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Rivera A, Vega C, Ramos-Rivera A, Maldonado ER, Prado GN, Karnes HE, Fesko YA, Snyder LM, Alper SL, Romero JR. Blockade of the mineralocorticoid receptor improves markers of human endothelial cell dysfunction and hematological indices in a mouse model of sickle cell disease. FASEB J 2023; 37:e23092. [PMID: 37482902 PMCID: PMC10372847 DOI: 10.1096/fj.202300671r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 06/24/2023] [Accepted: 07/03/2023] [Indexed: 07/25/2023]
Abstract
Increased endothelin-1 (ET-1) levels in patients with sickle cell disease (SCD) and transgenic mouse models of SCD contribute to disordered hematological, vascular, and inflammatory responses. Mineralocorticoid receptor (MR) activation by aldosterone, a critical component of the Renin-Angiotensin-Aldosterone-System, modulates inflammation and vascular reactivity, partly through increased ET-1 expression. However, the role of MR in SCD remains unclear. We hypothesized that MR blockade in transgenic SCD mice would reduce ET-1 levels, improve hematological parameters, and reduce inflammation. Berkeley SCD (BERK) mice, a model of severe SCD, were randomized to either sickle standard chow or chow containing the MR antagonist (MRA), eplerenone (156 mg/Kg), for 14 days. We found that MRA treatment reduced ET-1 plasma levels (p = .04), improved red cell density gradient profile (D50 ; p < .002), and increased mean corpuscular volume in both erythrocytes (p < .02) and reticulocytes (p < .024). MRA treatment also reduced the activity of the erythroid intermediate-conductance Ca2+ -activated K+ channel - KCa 3.1 (Gardos channel, KCNN4), reduced cardiac levels of mRNAs encoding ET-1, Tumor Necrosis Factor Receptor-1, and protein disulfide isomerase (PDI) (p < .01), and decreased plasma PDI and myeloperoxidase activity. Aldosterone (10-8 M for 24 h in vitro) also increased PDI mRNA levels (p < .01) and activity (p < .003) in EA.hy926 human endothelial cells, in a manner blocked by pre-incubation with the MRA canrenoic acid (1 μM; p < .001). Our results suggest a novel role for MR activation in SCD that may exacerbate SCD pathophysiology and clinical complications.
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Affiliation(s)
- Alicia Rivera
- Division of Nephrology, Vascular Biology Research Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
- Departments of Laboratory Medicine and Pathology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Christopher Vega
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Arelys Ramos-Rivera
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Enrique R Maldonado
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Gregory N Prado
- Departments of Laboratory Medicine and Pathology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | | | | | | | - Seth L Alper
- Division of Nephrology, Vascular Biology Research Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Jose R Romero
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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Romero JR, Inostroza‐Nieves Y, Pulido‐Perez P, Lopez P, Wohlgemuth JG, Dlott JS, Snyder LM, Alper SL, Rivera A. Magnesium homeostasis in deoxygenated sickle erythrocytes is modulated by endothelin-1 via Na + /Mg 2+ exchange. FASEB J 2022; 36:e22638. [PMID: 36331552 PMCID: PMC9703344 DOI: 10.1096/fj.202201339r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/14/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022]
Abstract
Painful crises in sickle cell disease (SCD) are associated with increased plasma cytokines levels, including endothelin-1 (ET-1). Reduced red cell magnesium content, mediated in part by increased Na+ /Mg2+ exchanger (NME) activity, contributes to erythrocyte K+ loss, dehydration and sickling in SCD. However, the relationship between ET-1 and the NME in SCD has remained unexamined. We observed increased NME activity in sickle red cells incubated in the presence of 500 nM ET-1. Deoxygenation of sickle red cells, in contrast, led to decreased red cell NME activity and cellular dehydration that was reversed by the NME inhibitor, imipramine. Increased NME activity in sickle red cells was significantly blocked by pre-incubation with 100 nM BQ788, a selective blocker of ET-1 type B receptors. These results suggest an important role for ET-1 and for cellular magnesium homeostasis in SCD. Consistent with these results, we observed increased NME activity in sickle red cells of three mouse models of sickle cell disease greater than that in red cells of C57BL/J6 mice. In vivo treatment of BERK sickle transgenic mice with ET-1 receptor antagonists reduced red cell NME activity. Our results suggest that ET-1 receptor blockade may be a promising therapeutic approach to control erythrocyte volume and magnesium homeostasis in SCD and may thus attenuate or retard the associated chronic inflammatory and vascular complications of SCD.
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Affiliation(s)
- José R. Romero
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, and Department of MedicineHarvard Medical SchoolBostonMassachusettsUSA
| | - Yaritza Inostroza‐Nieves
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, and Department of MedicineHarvard Medical SchoolBostonMassachusettsUSA,Department of Biochemistry and PharmacologySan Juan Bautista School of MedicineCaguasPuerto RicoUSA
| | - Patricia Pulido‐Perez
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, and Department of MedicineHarvard Medical SchoolBostonMassachusettsUSA
| | - Pablo Lopez
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, and Department of MedicineHarvard Medical SchoolBostonMassachusettsUSA
| | | | | | | | - Seth L. Alper
- Division of Nephrology and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, and Department of MedicineHarvard Medical SchoolBostonMassachusettsUSA
| | - Alicia Rivera
- Division of Nephrology and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, and Department of MedicineHarvard Medical SchoolBostonMassachusettsUSA,Division of Laboratory Medicine, Boston Children's Hospital, and Department of PathologyHarvard Medical SchoolBostonMassachusettsUSA
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Rivera A, Nasburg JA, Shim H, Shmukler BE, Kitten J, Wohlgemuth JG, Dlott JS, Snyder LM, Brugnara C, Wulff H, Alper SL. The erythroid K-Cl cotransport inhibitor [(dihydroindenyl)oxy]acetic acid blocks erythroid Ca 2+-activated K + channel KCNN4. Am J Physiol Cell Physiol 2022; 323:C694-C705. [PMID: 35848620 PMCID: PMC9448282 DOI: 10.1152/ajpcell.00240.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/07/2022] [Accepted: 07/08/2022] [Indexed: 11/22/2022]
Abstract
Red cell volume is a major determinant of HbS concentration in sickle cell disease. Cellular deoxy-HbS concentration determines the delay time, the interval between HbS deoxygenation and deoxy-HbS polymerization. Major membrane transporter protein determinants of sickle red cell volume include the SLC12/KCC K-Cl cotransporters KCC3/SLC12A6 and KCC1/SLC12A4, and the KCNN4/KCa3.1 Ca2+-activated K+ channel (Gardos channel). Among standard inhibitors of KCC-mediated K-Cl cotransport, only [(dihydroindenyl)oxy]acetic acid (DIOA) has been reported to lack inhibitory activity against the related bumetanide-sensitive erythroid Na-K-2Cl cotransporter NKCC1/SLC12A2. DIOA has been often used to inhibit K-Cl cotransport when studying the expression and regulation of other K+ transporters and K+ channels. We report here that DIOA at concentrations routinely used to inhibit K-Cl cotransport can also abrogate activity of the KCNN4/KCa3.1 Gardos channel in human and mouse red cells and in human sickle red cells. DIOA inhibition of A23187-stimulated erythroid K+ uptake (Gardos channel activity) was chloride-independent and persisted in mouse red cells genetically devoid of the principal K-Cl cotransporters KCC3 and KCC1. DIOA also inhibited YODA1-stimulated, chloride-independent erythroid K+ uptake. In contrast, DIOA exhibited no inhibitory effect on K+ influx into A23187-treated red cells of Kcnn4-/- mice. DIOA inhibition of human KCa3.1 was validated (IC50 42 µM) by whole cell patch clamp in HEK-293 cells. RosettaLigand docking experiments identified a potential binding site for DIOA in the fenestration region of human KCa3.1. We conclude that DIOA at concentrations routinely used to inhibit K-Cl cotransport can also block the KCNN4/KCa3.1 Gardos channel in normal and sickle red cells.
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Affiliation(s)
- Alicia Rivera
- Division of Nephrology and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Joshua A Nasburg
- Department of Pharmacology, School of Medicine, University of California, Davis, California
| | - Heesung Shim
- Department of Pharmacology, School of Medicine, University of California, Davis, California
| | - Boris E Shmukler
- Division of Nephrology and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | | | | | | | | | - Carlo Brugnara
- Department of Laboratory Medicine, Boston Children's Hospital, Boston, Massachusetts
- Department of Pathology, Harvard Medical School, Boston, Massachusetts
| | - Heike Wulff
- Department of Pharmacology, School of Medicine, University of California, Davis, California
| | - Seth L Alper
- Division of Nephrology and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
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Heneghan JF, Majmundar AJ, Rivera A, Wohlgemuth JG, Dlott JS, Snyder LM, Hildebrandt F, Alper SL. Activation of 2-oxoglutarate receptor 1 (OXGR1) by α-ketoglutarate (αKG) does not detectably stimulate Pendrin-mediated anion exchange in Xenopus oocytes. Physiol Rep 2022; 10:e15362. [PMID: 35851763 PMCID: PMC9294391 DOI: 10.14814/phy2.15362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 06/01/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023] Open
Abstract
SLC26A4/Pendrin is the major electroneutral Cl- /HCO3- exchanger of the apical membrane of the Type B intercalated cell (IC) of the connecting segment (CNT) and cortical collecting duct (CCD). Pendrin mediates both base secretion in response to systemic base load and Cl- reabsorption in response to systemic volume depletion, manifested as decreased nephron salt and water delivery to the distal nephron. Pendrin-mediated Cl- /HCO3- exchange in the apical membrane is upregulated through stimulation of the β-IC apical membrane G protein-coupled receptor, 2-oxoglutarate receptor 1 (OXGR1/GPR99), by its ligand α-ketoglutarate (αKG). αKG is both filtered by the glomerulus and lumenally secreted by proximal tubule apical membrane organic anion transporters (OATs). OXGR1-mediated regulation of Pendrin by αKG has been documented in transgenic mice and in isolated perfused CCD. However, aspects of the OXGR1 signaling pathway have remained little investigated since its original discovery in lymphocytes. Moreover, no ex vivo cellular system has been reported in which to study the OXGR1 signaling pathway of Type B-IC, a cell type refractory to survival in culture in its differentiated state. As Xenopus oocytes express robust heterologous Pendrin activity, we investigated OXGR1 regulation of Pendrin in oocytes. Despite functional expression of OXGR1 in oocytes, co-expression of Pendrin and OXGR1 failed to exhibit αKG-sensitive stimulation of Pendrin-mediated Cl- /anion exchange under a wide range of conditions. We conclude that Xenopus oocytes lack one or more essential molecular components or physical conditions required for OXGR1 to regulate Pendrin activity.
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Affiliation(s)
- John F. Heneghan
- Division of NephrologyBeth Israel Deaconess Medical CenterBostonMassachusettsUSA
- Department of MedicineHarvard Medical SchoolBostonMassachusettsUSA
| | - Amar J. Majmundar
- Division of NephrologyBoston Children's HospitalBostonMassachusettsUSA
- Department of PediatricsHarvard Medical SchoolBostonMassachusettsUSA
| | - Alicia Rivera
- Division of NephrologyBeth Israel Deaconess Medical CenterBostonMassachusettsUSA
- Department of MedicineHarvard Medical SchoolBostonMassachusettsUSA
| | | | | | | | - Friedhelm Hildebrandt
- Division of NephrologyBoston Children's HospitalBostonMassachusettsUSA
- Department of PediatricsHarvard Medical SchoolBostonMassachusettsUSA
- Department of GeneticsHarvard Medical SchoolBostonMassachusettsUSA
| | - Seth L. Alper
- Division of NephrologyBeth Israel Deaconess Medical CenterBostonMassachusettsUSA
- Department of MedicineHarvard Medical SchoolBostonMassachusettsUSA
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Ferreira A, Rivera A, Wohlgemuth JG, Dlott JS, Snyder LM, Alper SL, Romero JR. Dysregulated Erythroid Mg2+ Efflux in Type 2 Diabetes. Front Cell Dev Biol 2022; 10:861644. [PMID: 35445032 PMCID: PMC9013827 DOI: 10.3389/fcell.2022.861644] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/09/2022] [Indexed: 12/23/2022] Open
Abstract
Hyperglycemia is associated with decreased Mg2+ content in red blood cells (RBC), but mechanisms remain unclear. We characterized the regulation of Mg2+ efflux by glucose in ex vivo human RBC. We observed that hemoglobin A1C (HbA1C) values correlated with Na+-dependent Mg2+ efflux (Na+/Mg2+ exchange) and inversely correlated with cellular Mg content. Treatment of cells with 50 mM D-glucose, but not with sorbitol, lowered total cellular Mg (2.2 ± 0.1 to 2.0 ± 0.1 mM, p < 0.01) and enhanced Na+/Mg2+ exchange activity [0.60 ± 0.09 to 1.12 ± 0.09 mmol/1013 cell × h (flux units, FU), p < 0.05]. In contrast, incubation with selective Src family kinase inhibitors PP2 or SU6656 reduced glucose-stimulated exchange activation (p < 0.01). Na+/Mg2+ exchange activity was also higher in RBC from individuals with type 2 diabetes (T2D, 1.19 ± 0.13 FU) than from non-diabetic individuals (0.58 ± 0.05 FU, p < 0.01). Increased Na+/Mg2+ exchange activity in RBC from T2D subjects was associated with lower intracellular Mg content. Similarly increased exchange activity was evident in RBC from the diabetic db/db mouse model as compared to its non-diabetic control (p < 0.03). Extracellular exposure of intact RBC from T2D subjects to recombinant peptidyl-N-glycosidase F (PNGase F) reduced Na+/Mg2+ exchange activity from 0.98 ± 0.14 to 0.59 ± 0.13 FU (p < 0.05) and increased baseline intracellular Mg content (1.8 ± 0.1 mM) to normal values (2.1 ± 0.1 mM, p < 0.05). These data suggest that the reduced RBC Mg content of T2D RBC reflects enhanced RBC Na+/Mg2+ exchange subject to regulation by Src family kinases and by the N-glycosylation state of one or more membrane proteins. The data extend our understanding of dysregulated RBC Mg2+ homeostasis in T2D.
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Affiliation(s)
- Ana Ferreira
- Interdisciplinary Centre of Social Sciences (CICS.NOVA), Faculty of Social Sciences and Humanities (NOVA FCSH), Lisbon, Portugal
| | - Alicia Rivera
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
- *Correspondence: Alicia Rivera,
| | | | | | | | - Seth L. Alper
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Jose R. Romero
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, United States
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6
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Shmukler BE, Rivera A, Nishimura K, Hsu A, Wohlgemuth JG, Dlott JS, Michael Snyder L, Brugnara C, Alper SL. Erythroid-specific inactivation of Slc12a6/Kcc3 by EpoR promoter-driven Cre expression reduces K-Cl cotransport activity in mouse erythrocytes. Physiol Rep 2022; 10:e15186. [PMID: 35274823 PMCID: PMC8915159 DOI: 10.14814/phy2.15186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 11/24/2022] Open
Abstract
Investigation of erythrocytes from spontaneous or engineered germ‐line mutant mice has been instrumental in characterizing the physiological functions of components of the red cell cytoskeleton and membrane. However, the red blood cell expresses some proteins whose germline loss‐of‐function is embryonic‐lethal, perinatal‐lethal, or confers reduced post‐weaning viability. Promoter regions of erythroid‐specific genes have been used to engineer erythroid‐specific expression of Cre recombinase. Through breeding with mice carrying appropriately spaced insertions of loxP sequences, generation of erythroid‐specific knockouts has been carried out for signaling enzymes, transcription factors, peptide hormones, and single transmembrane span signaling receptors. We report here the use of Cre recombinase expression driven by the erythropoietin receptor (EpoR) promoter to generate EpoR‐Cre;Kcc3f/f mice, designed to express erythroid‐specific knockout of the KCC3 K‐Cl cotransporter encoded by Kcc3/Slc12A6. We confirm KCC3 as the predominant K‐Cl cotransporter of adult mouse red cells in mice with better viability than previously exhibited by Kcc3−/− germline knockouts. We demonstrate roughly proportionate preservation of K‐Cl stimulation by hypotonicity, staurosporine, and urea in the context of reduced, but not abrogated, K‐Cl function in EpoR‐Cre;Kcc3f/f mice. We also report functional evidence suggesting incomplete recombinase‐mediated excision of the Kcc3 gene in adult erythroid tissues.
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Affiliation(s)
- Boris E Shmukler
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Alicia Rivera
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Katherine Nishimura
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Ann Hsu
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | | | | | | | - Carlo Brugnara
- Department of Laboratory Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA
| | - Seth L Alper
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.,Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
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Vandorpe DH, Shmukler BE, Ilboudo Y, Bhasin S, Thomas B, Rivera A, Wohlgemuth JG, Dlott JS, Snyder LM, Sieff C, Bhasin M, Lettre G, Brugnara C, Alper SL. A Grammastola spatulata mechanotoxin-4 (GsMTx4)-sensitive cation channel mediates increased cation permeability in human hereditary spherocytosis of multiple genetic etiologies. Haematologica 2021; 106:2759-2762. [PMID: 34109777 PMCID: PMC8485688 DOI: 10.3324/haematol.2021.278770] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Indexed: 11/09/2022] Open
Affiliation(s)
- David H Vandorpe
- Division of Nephrology and Vascular Biology Research Center, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, MA 02215
| | - Boris E Shmukler
- Division of Nephrology and Vascular Biology Research Center, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, MA 02215
| | - Yann Ilboudo
- Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada, H1T 1C8
| | - Swati Bhasin
- Division of Integrative Medicine and Vascular Biology Research Center, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, MA 02215
| | - Beena Thomas
- Division of Integrative Medicine and Vascular Biology Research Center, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, MA 02215
| | - Alicia Rivera
- Division of Nephrology and Vascular Biology Research Center, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, MA 02215
| | | | | | | | - Colin Sieff
- Cancer and Blood Disorders Center, Dana-Farber Cancer Center and Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, MA 02115
| | - Manoj Bhasin
- Division of Integrative Medicine and Vascular Biology Research Center, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, MA 02215
| | - Guillaume Lettre
- Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada, H1T 1C8
| | - Carlo Brugnara
- Department of Laboratory Medicine, Boston Children's Hospital and Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Seth L Alper
- Division of Nephrology and Vascular Biology Research Center, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, MA 02215.
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Shmukler BE, Rivera A, Bhargava P, Nishimura K, Kim EH, Hsu A, Wohlgemuth JG, Morton J, Snyder LM, De Franceschi L, Rust MB, Hubner CA, Brugnara C, Alper SL. Genetic disruption of KCC cotransporters in a mouse model of thalassemia intermedia. Blood Cells Mol Dis 2020; 81:102389. [PMID: 31835175 PMCID: PMC7002294 DOI: 10.1016/j.bcmd.2019.102389] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/14/2019] [Accepted: 11/15/2019] [Indexed: 02/07/2023]
Abstract
β-thalassemia (β-Thal) is caused by defective β-globin production leading to globin chain imbalance, aggregation of free alpha chain in developing erythroblasts, reticulocytes, and mature circulating red blood cells. The hypochromic thalassemic red cells exhibit increased cell dehydration in association with elevated K+ leak and increased K-Cl cotransport activity, each of which has been linked to globin chain imbalance and related oxidative stress. We therefore tested the effect of genetic inactivation of K-Cl cotransporters KCC1 and KCC3 in a mouse model of β-thalassemia intermedia. In the absence of these transporters, the anemia of β-Thal mice was ameliorated, in association with increased MCV and reductions in CHCM and hyperdense cells, as well as in spleen size. The resting K+ content of β-Thal red cells was greatly increased, and Thal-associated splenomegaly slightly decreased. Lack of KCC1 and KCC3 activity in Thal red cells reduced red cell density and improved β-Thal-associated osmotic fragility. We conclude that genetic inactivation of K-Cl cotransport can reverse red cell dehydration and partially attenuate the hematologic phenotype in a mouse model of β-thalassemia.
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Affiliation(s)
- Boris E Shmukler
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA 02215, United States of America; Department of Medicine, Harvard Medical School, Boston, MA 02215, United States of America
| | - Alicia Rivera
- Department of Laboratory Medicine, Boston Children's Hospital, Boston, MA 02115, United States of America; Department of Pathology, Harvard Medical School, Boston, MA 02115, United States of America
| | - Parul Bhargava
- Department of Laboratory Medicine, UCSF, San Francisco, CA, United States of America
| | - Katherine Nishimura
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA 02215, United States of America
| | - Edward H Kim
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA 02215, United States of America
| | - Ann Hsu
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA 02215, United States of America
| | - Jay G Wohlgemuth
- Quest Diagnostics, San Juan Capistrano, CA, United States of America
| | - James Morton
- Quest Diagnostics, San Juan Capistrano, CA, United States of America
| | | | - Lucia De Franceschi
- Dept. of Medicine, Universita Verona and Azienda Ospedaliera Universitaria Verona, Policlinico GB Rossi, Verona, Italy
| | - Marco B Rust
- Institute of Physiological Chemistry, Philipps-Universität Marburg, Marburg, Germany
| | | | - Carlo Brugnara
- Department of Medicine, Harvard Medical School, Boston, MA 02215, United States of America; Department of Laboratory Medicine, Boston Children's Hospital, Boston, MA 02115, United States of America
| | - Seth L Alper
- Renal Division and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Boston, MA 02215, United States of America; Department of Pathology, Harvard Medical School, Boston, MA 02115, United States of America.
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9
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Rivera A, Vandorpe DH, Shmukler BE, Andolfo I, Iolascon A, Archer NM, Shabani E, Auerbach M, Hamerschlak N, Morton J, Wohlgemuth JG, Brugnara C, Snyder LM, Alper SL. Erythrocyte ion content and dehydration modulate maximal Gardos channel activity in KCNN4 V282M/+ hereditary xerocytosis red cells. Am J Physiol Cell Physiol 2019; 317:C287-C302. [PMID: 31091145 DOI: 10.1152/ajpcell.00074.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hereditary xerocytosis (HX) is caused by missense mutations in either the mechanosensitive cation channel PIEZO1 or the Ca2+-activated K+ channel KCNN4. All HX-associated KCNN4 mutants studied to date have revealed increased current magnitude and red cell dehydration. Baseline KCNN4 activity was increased in HX red cells heterozygous for KCNN4 mutant V282M. However, HX red cells maximally stimulated by Ca2+ ionophore A23187 or by PMCA Ca2+-ATPase inhibitor orthovanadate displayed paradoxically reduced KCNN4 activity. This reduced Ca2+-stimulated mutant KCNN4 activity in HX red cells was associated with unchanged sensitivity to KCNN4 inhibitor senicapoc and KCNN4 activator Ca2+, with slightly elevated Ca2+ uptake and reduced PMCA activity, and with decreased KCNN4 activation by calpain inhibitor PD150606. The altered intracellular monovalent cation content of HX red cells prompted experimental nystatin manipulation of red cell Na and K contents. Nystatin-mediated reduction of intracellular K+ with corresponding increase in intracellular Na+ in wild-type cells to mimic conditions of HX greatly suppressed vanadate-stimulated and A23187-stimulated KCNN4 activity in those wild-type cells. However, conferral of wild-type cation contents on HX red cells failed to restore wild-type-stimulated KCNN4 activity to those HX cells. The phenotype of reduced, maximally stimulated KCNN4 activity was shared by HX erythrocytes expressing heterozygous PIEZO1 mutants R2488Q and V598M, but not by HX erythrocytes expressing heterozygous KCNN4 mutant R352H or PIEZO1 mutant R2456H. Our data suggest that chronic KCNN4-driven red cell dehydration and intracellular cation imbalance can lead to reduced KCNN4 activity in HX and wild-type red cells.
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Affiliation(s)
- Alicia Rivera
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - David H Vandorpe
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Boris E Shmukler
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Immacolata Andolfo
- Department of Molecular Medicine and Medical Biotechnologies, "Federico II" University of Naples, CEINGE Biotecnologie Avanzate, Naples, Italy
| | - Achille Iolascon
- Department of Molecular Medicine and Medical Biotechnologies, "Federico II" University of Naples, CEINGE Biotecnologie Avanzate, Naples, Italy
| | - Natasha M Archer
- Division of Hematology and Oncology, Boston Children's Hospital, Dana-Farber Cancer Center, Department of Pediatrics, Harvard Medical School, Boston, Massachusetts
| | - Estela Shabani
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | | | - Nelson Hamerschlak
- Department of Hematology, Hospital Israelita Albert Einstein, Sao Paulo, Brazil
| | - James Morton
- Quest Diagnostics, San Juan Capistrano, California
| | | | - Carlo Brugnara
- Department of Laboratory Medicine, Boston Children's Hospital and Department of Pathology, Harvard Medical School, Boston, Massachusetts
| | - L Michael Snyder
- Quest Diagnostics, Marlborough, Massachusetts.,Departments of Medicine and Laboratory Medicine, University of Massachusetts Medical Center, Worcester, Massachusetts
| | - Seth L Alper
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.,Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts
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10
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Lewandrowski K, Keegan A, Makarenko V, Maryamchak E, Mata DA, Palte MJ, Rudolf JW, Safdar N, Schmidt RJ, Stuart L, Xiong Y, Rao L, Melanson SEF, Michael Snyder L. Development of a Commercial Reference Laboratory Elective Rotation for Residents in Clinical Pathology. Am J Clin Pathol 2018; 150:485-490. [PMID: 30053105 DOI: 10.1093/ajcp/aqy070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES To develop a curriculum for a commercial reference laboratory clinical pathology training elective. METHODS A 4-day elective at Quest Diagnostics was developed. The elective included 32 sessions composed of interactive didactic sessions and laboratory tours/demonstrations. Ten residents who attended the elective completed a written evaluation and scored each component of the curriculum. RESULTS Written comments were very positive and demonstrated the goals of the elective were achieved. Laboratory tours and one-on-one sessions with the medical directors were especially well received. Most of the residents stated that the rotation gave them exposure to an area of laboratory medicine that they were not familiar with. CONCLUSIONS The elective provided a resident training experience that was highly regarded and exposed residents to an area of laboratory medicine not encountered in most pathology training programs. Our curriculum could serve as a model for establishing a similar elective in other training programs.
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Affiliation(s)
- Kent Lewandrowski
- Department of Pathology, Massachusetts General Hospital, Boston
- Department of Pathology, Harvard Medical School, Boston, MA
| | - Alissa Keegan
- Department of Pathology, Harvard Medical School, Boston, MA
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA
| | | | - Elena Maryamchak
- Department of Pathology, Massachusetts General Hospital, Boston
- Department of Pathology, Harvard Medical School, Boston, MA
| | - Douglas A Mata
- Department of Pathology, Harvard Medical School, Boston, MA
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA
| | - Michael J Palte
- Department of Pathology, Harvard Medical School, Boston, MA
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA
| | - Joseph W Rudolf
- Department of Pathology, University of Minnesota Medical School, Minneapolis
| | - Nida Safdar
- Department of Pathology, Massachusetts General Hospital, Boston
- Department of Pathology, Harvard Medical School, Boston, MA
| | - Ryan J Schmidt
- Department of Pathology, Harvard Medical School, Boston, MA
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA
| | - Lena Stuart
- Department of Pathology, Massachusetts General Hospital, Boston
- Department of Pathology, Harvard Medical School, Boston, MA
| | | | - Lokinendi Rao
- UMass Memorial Medical Center, Worcester
- Quest Diagnostics, Marlborough, MA
| | - Stacy E F Melanson
- Department of Pathology, Harvard Medical School, Boston, MA
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA
| | - L Michael Snyder
- UMass Memorial Medical Center, Worcester
- Quest Diagnostics, Marlborough, MA
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11
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Kaufman HW, Niles JK, Gallagher DR, Rivera A, Alper SL, Brugnara C, Snyder LM. Revised prevalence estimate of possible Hereditary Xerocytosis as derived from a large U.S. Laboratory database. Am J Hematol 2018; 93:E9-E12. [PMID: 28971500 DOI: 10.1002/ajh.24923] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 09/27/2017] [Indexed: 11/12/2022]
Affiliation(s)
| | | | | | - Alicia Rivera
- Division of Nephrology and Vascular Biology Research Center; Beth Israel Deaconess Medical Center, and Department of Medicine, Harvard Medical School; Boston Massachusetts 02215
| | - Seth L. Alper
- Division of Nephrology and Vascular Biology Research Center; Beth Israel Deaconess Medical Center, and Department of Medicine, Harvard Medical School; Boston Massachusetts 02215
| | - Carlo Brugnara
- Department of Laboratory Medicine, Boston Children's Hospital and Department of Pathology; Harvard Medical School; Boston Massachusetts 02115
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12
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Rivera A, Vandorpe DH, Shmukler BE, Gallagher DR, Fikry CC, Kuypers FA, Brugnara C, Snyder LM, Alper SL. Erythrocytes from hereditary xerocytosis patients heterozygous for KCNN4 V282M exhibit increased spontaneous Gardos channel-like activity inhibited by senicapoc. Am J Hematol 2017; 92:E108-E110. [PMID: 28295477 DOI: 10.1002/ajh.24716] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 03/08/2017] [Indexed: 01/08/2023]
Affiliation(s)
- Alicia Rivera
- Division of Nephrology; Beth Israel Deaconess Medical Center; Boston Massachusetts USA
- Department of Medicine; Harvard Medical School; Boston Massachusetts USA
| | - David H. Vandorpe
- Division of Nephrology; Beth Israel Deaconess Medical Center; Boston Massachusetts USA
- Department of Medicine; Harvard Medical School; Boston Massachusetts USA
| | - Boris E. Shmukler
- Division of Nephrology; Beth Israel Deaconess Medical Center; Boston Massachusetts USA
- Department of Medicine; Harvard Medical School; Boston Massachusetts USA
| | | | | | - Frans A. Kuypers
- Childrens' Hospital of Oakland Research Institute; Oakland California USA
| | - Carlo Brugnara
- Division of Laboratory Medicine; Boston Childrens' Hospital, Harvard Medical School; Boston Massachusetts USA
- Department of Pathology; Harvard Medical School; Boston Massachusetts USA
| | - L. Michael Snyder
- Quest Diagnostics; Marlborough Massachusetts USA
- Departments of Medicine and Pathology; UMass Memorial Medical Center; Worcester Massachusetts USA
| | - Seth L. Alper
- Division of Nephrology; Beth Israel Deaconess Medical Center; Boston Massachusetts USA
- Department of Medicine; Harvard Medical School; Boston Massachusetts USA
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13
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Jamshed S, Snyder LM. An Intact Dissecting Baker's Cyst Mimicking Recurrent Deep Vein Thrombosis. J Investig Med High Impact Case Rep 2016; 4:2324709616650703. [PMID: 27231697 PMCID: PMC4871195 DOI: 10.1177/2324709616650703] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 04/19/2016] [Indexed: 11/17/2022] Open
Abstract
We report a case of a 75-year-old female with a history of acute deep vein thrombosis (DVT) 6 years ago who presented with unilateral calf swelling and pain. D-dimer was normal, and compression ultrasound revealed findings typical of DVT, including an incompressible dilated and hypoechoic peroneal vein. Despite 4 months of anticoagulation for supposed recurrent DVT, pain symptoms persisted and repeat D-dimer and compression ultrasound were unchanged. A magnetic resonance imaging scan to investigate the leg demonstrated a 6-cm dissecting Baker's cyst extending posterolaterally resulting in venous compression and distal dilation, which appeared to have been confused with a DVT. Ultrasound-guided aspiration of the cyst provided immediate and sustained relief. Herein we provide a review of the literature for the management of this rare scenario.
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Affiliation(s)
- Sarah Jamshed
- University of Massachusetts Medical School, Worcester, MA, USA
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14
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Andolfo I, Russo R, Manna F, Shmukler BE, Gambale A, Vitiello G, De Rosa G, Brugnara C, Alper SL, Snyder LM, Iolascon A. Novel Gardos channel mutations linked to dehydrated hereditary stomatocytosis (xerocytosis). Am J Hematol 2015; 90:921-6. [PMID: 26178367 DOI: 10.1002/ajh.24117] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 07/08/2015] [Indexed: 02/06/2023]
Abstract
Dehydrated hereditary stomatocytosis (DHSt) is an autosomal dominant congenital hemolytic anemia with moderate splenomegaly and often compensated hemolysis. Affected red cells are characterized by a nonspecific cation leak of the red cell membrane, reflected in elevated sodium content, decreased potassium content, elevated MCHC and MCV, and decreased osmotic fragility. The majority of symptomatic DHSt cases reported to date have been associated with gain-of-function mutations in the mechanosensitive cation channel gene, PIEZO1. A recent study has identified two families with DHSt associated with a single mutation in the KCNN4 gene encoding the Gardos channel (KCa3.1), the erythroid Ca(2+) -sensitive K(+) channel of intermediate conductance, also expressed in many other cell types. We present here, in the second report of DHSt associated with KCNN4 mutations, two previously undiagnosed DHSt families. Family NA exhibited the same de novo missense mutation as that recently described, suggesting a hot spot codon for DHSt mutations. Family WO carried a novel, inherited missense mutation in the ion transport domain of the channel. The patients' mild hemolytic anemia did not improve post-splenectomy, but splenectomy led to no serious thromboembolic events. We further characterized the expression of KCNN4 in the mutated patients and during erythroid differentiation of CD34+ cells and K562 cells. We also analyzed KCNN4 expression during mouse embryonic development.
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Affiliation(s)
- Immacolata Andolfo
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
| | - Roberta Russo
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
| | - Francesco Manna
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
| | - Boris E. Shmukler
- Renal Division And Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Harvard Medical School; Boston Massachusetts
- Department Of Medicine, Harvard Medical School; Boston Massachusetts
| | - Antonella Gambale
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
| | - Giuseppina Vitiello
- Biotecnologie Avanzate; CEINGE; Naples Italy
- Medical Genetics Unit; Policlinico Tor Vergata University Hospital; Viale Oxford Rome Italy
| | - Gianluca De Rosa
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
| | - Carlo Brugnara
- Department Of Laboratory Medicine, Boston Children's Hospital And Department Of Pathology; Harvard Medical School; Boston Massachusetts
| | - Seth L. Alper
- Renal Division And Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Harvard Medical School; Boston Massachusetts
| | - L. Michael Snyder
- Dept Of Hospital Laboratories; University Of Massachusetts Medical Center; Worcester MA
- Quest Diagnositics, LLC MA; Marlborough Massachusetts
| | - Achille Iolascon
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
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15
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Kiefer CR, Stock RE, Flanagan SS, Darling CE, Smith CS, Snyder LM. Early verification of myocardial ischemia with a novel biomarker of acute tissue damage: C-reactive protein fractional forms. Clin Chim Acta 2012; 413:1536-41. [PMID: 22735342 DOI: 10.1016/j.cca.2012.06.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND We evaluated the utility of an independent biomarker of early ischemic cellular damage-circulating fractional forms of C-reactive protein (fracCRP), to verify the diagnostic relevance of low Troponin I (TnI) values within the context of a workup for Acute Coronary Syndrome (ACS). METHODS On a semi-preparative scale, the molecular characteristics of fracCRP were established by electron microscopy and Western Blot, using isolates captured from patient serum on phosphorylcholine beads and purified by size exclusion high-pressure liquid chromatography (SE-HPLC). Captured on an analytical scale, the diagnostic utility of fracCRP was evaluated in first-draw plasma specimens (total CRP not exceeding 6 mg/l) recovered from 300 cardiac emergency patients with final discharge diagnoses of ACS ruled out (N=132) or ruled in (N=168). RESULTS At a cutoff value chosen for 97.7% test specificity, the test metric (fracCRP×TnI) identified in the first blood draw 39.9% of all emergency patients ultimately diagnosed with ACS, and 17.9% of ultimately diagnosed patients who arrived with TnI values within the normal reference range (0.01-0.04 ng/ml). CONCLUSIONS These findings suggest that the fracCRP test metric could serve as a rule-in test for ACS in a significant proportion of low to moderate risk emergency patients.
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Affiliation(s)
- Charles R Kiefer
- Department of Hospital Laboratories, UMass Memorial Medical Center, One Biotech Park, 365 Plantation Street, Worcester, MA 01605, USA.
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16
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Yu H, Ok CY, Hesse A, Nordell P, Connor D, Sjostedt E, Pechet L, Snyder LM. Evaluation of an Automated Digital Imaging System, Nextslide Digital Review Network, for Examination of Peripheral Blood Smears. Arch Pathol Lab Med 2012; 136:660-7. [PMID: 22646275 DOI: 10.5858/arpa.2011-0285-oa] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Context.—Several automated digital imaging systems have been introduced in recent years to improve turnaround time and proficiency in examining peripheral blood smears in hematology laboratories.
Objective.—To evaluate a new automated digital imaging system, Nextslide Digital Review Network (Nextslide), for examination of peripheral blood smears.
Design.—We evaluated 479 peripheral blood smears, of which 247 (51.6%) were included for comparison of Nextslide and manual white blood cell differential counts and morphology evaluation, 204 (42.6%) were included for comparison of Nextslide and CellaVision (DM96) differential counts, and 28 (5.8%) were neonatal samples examined for enumeration of nucleated red blood cells.
Results.—Results from both method comparisons showed excellent correlation for all major white blood cell classes with correlation coefficients ranging from 0.70 to 0.99. Evaluation of white blood cell, red blood cell, and platelet morphology also showed good correlation among methods. White blood cell preclassification capability in the system was evaluated for rate and accuracy. Leukopenic samples demonstrated markedly decreased review time with Nextslide. Enumeration of nucleated red blood cells showed good correlation among methods.
Conclusions.—Our evaluation of Nextslide shows excellent correlation when compared with conventional manual differentials and CellaVision (DM96) differentials for evaluation of peripheral blood smears.
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Affiliation(s)
- Hongbo Yu
- Department of Hospital Laboratories and Department of Pathology, University of Massachusetts Memorial Medical Center, One Biotech Park, 365 Plantation Street, Worcester, MA 01605, USA.
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17
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Contois JH, Hartigan C, Rao LV, Snyder LM, Thompson MJ. Analytical validation of an HPLC assay for urinary albumin. Clin Chim Acta 2006; 367:150-5. [PMID: 16423336 DOI: 10.1016/j.cca.2005.12.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 12/05/2005] [Accepted: 12/05/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Microalbuminuria is the earliest clinical finding for renal disease. Diabetic individuals often produce modified forms of albumin, perhaps due to impaired lysosomal processing, that are undetectable by common immunoassays but accurately measured by HPLC. METHODS We evaluated the performance of a commercially available, FDA-approved HPLC assay (AusAm Biotechnologies, NY) and compare results to our immunoturbidimetric assay (ITA, Beckman-Coulter, CA) using random urine specimens from 32 nondiabetic and 60 type 1 and 2 diabetic subjects. RESULTS The HPLC assay was linear to 963 mg/l with a limit of detection of 6.1 mg/l. Within-run and between-run precision was <2% and 7-10%, respectively. Unpreserved urine was stable for at least 3 days at room temperature and 10 days at 4 degrees C. In both diabetic and nondiabetic subjects urinary albumin concentrations were higher by HPLC than by ITA, and many more diabetic and nondiabetic individuals were classified as microalbuminuric by HPLC than by ITA. The HPLC assay showed acceptable performance; however, because urinary albumin concentrations are higher in apparently healthy nondiabetic as well as diabetic subjects, different cutpoints will be necessary to accurately differentiate microalbuminuria. CONCLUSIONS Prospective studies are necessary to determine whether the HPLC assay can effectively detect microalbuminuria earlier than current assays without a concomitant increase in the false positive rate.
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Affiliation(s)
- John H Contois
- Department of Hospital Laboratories, UMass Memorial Medical Center, Worcester, MA, USA.
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18
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Kiefer CR, McKenney JB, Trainor JF, Snyder LM. Pulse pressure-driven neutral lipid accumulation and correlative proinflammatory markers of accelerated atherogenesis. Atherosclerosis 2005; 183:17-24. [PMID: 16216588 DOI: 10.1016/j.atherosclerosis.2005.02.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Revised: 01/12/2005] [Accepted: 02/15/2005] [Indexed: 11/23/2022]
Abstract
In athero-prone areas of the human aorta, an accumulation of neutral lipids in the arterial intima precedes the arrival of monocytes and the initiation of the fatty streak. This study continues the investigation of a similar preinflammatory process in the coronary arteries of the sodium-sensitive hypertensive Dahl S rat, focusing on the hemodynamic forces associated with the neutral lipid influx and on concurrent changes in serum levels of certain proinflammatory markers. Animals were conditioned from weaning on a high-saturated fat, high-cholesterol diet until early adolescence (age 12 weeks), at which point dietary sodium was increased, and changes in blood pressure, serum analytes and histologic markers were tracked. The first half of the 12-day induction period was characterized by an immediate rise in pulse pressure that persisted above baseline. Serum levels of free monomeric C-reactive protein (mCRP) (as monomer/dimer ratio by Western blot densitometry) rose concurrently with pulse pressure and preceded the influx of neutral lipid into the arterial intima. Levels of oxidized LDL-cholesterol (oxLDL) closely tracked that of neutral lipid accumulation. In this model, elevated pulse pressure appears to drive the activation of circulating CRP and the influx of neutral lipids into the arterial intima, which leads to increased oxLDL levels.
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Affiliation(s)
- Charles R Kiefer
- Department of Hospital Laboratories, UMass Memorial Medical Center, One Biotech Park, Suite 200, 365 Plantation Street, Worcester, MA 01605-2376, USA.
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19
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Kiefer CR, McKenney JB, Trainor JF, Snyder LM. Maturation-dependent acquired coronary structural alterations and atherogenesis in the Dahl sodium-sensitive hypertensive rat. Circulation 2002; 106:2486-90. [PMID: 12417547 DOI: 10.1161/01.cir.0000036599.31371.8f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The Dahl sodium-sensitive hypertensive rat exhibits atherogenic lesions after the initiation of a high-sodium/high-fat diet. This study was designed to gauge the effect of a preadolescent high-fat diet on the postadolescent rate of atherogenesis after supplementation of the diet with sodium. METHODS AND RESULTS Fifty-three Dahl S male rats were assigned to 2 dietary groups for the postweaning to early adolescence period (3 to 12 weeks): 29 to a standard diet (low-fat/low-sodium) and 24 to a high-fat/low-sodium diet. At age 9 weeks (just after puberty), animals from the high-fat group exhibited a relatively diminished density of coronary elastic fibers. There was no evidence of either lipid or monocytic infiltration of the subendothelial space. At age 12 weeks, most or all of the remaining animals in both groups were switched to a high-sodium/high-fat diet and were sampled through the following 8 weeks for the appearance of arterial lipid. After the switch, the high-fat-conditioned animals developed more extensive atherosclerotic pathological lesions more rapidly than their prepubertal standard-diet counterparts. The importance of the animal's stage of maturation in this effect was underscored by the observation that delaying onset of the high-fat diet to early adolescence resulted in no ultimate difference from the pubertal controls in elastic fiber density. CONCLUSIONS The maturation-dependent high-fat conditioning of these postweanling rats correlated with an accelerated rate of atherogenesis on the initiation of the high-sodium/high-fat diet, possibly as a direct result of an alteration in arterial elasticity.
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Affiliation(s)
- Charles R Kiefer
- Department of Hospital Laboratories, UMass Memorial Medical Center, Worcester, Mass 01605-2376, USA.
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20
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Abstract
Direct macrophage recognition of an externalized phosphatidylserine signal on senescent erythrocytes is a process of erythrophagocytic clearance that is in line with the general clearance process of all other circulating cells that become apoptotic. Advances in deciphering this process suggest that oxidation of the erythrocyte's hemoglobin, the salient target of the free radicals encountered in the circulatory environment, may drive subsequent steps. The progressive accumulation of oxidized hemoglobin covalently bound to the membrane skeleton not only disrupts membrane organization but also threatens eventual phospholipid oxidation via a calcium-promoted quasi-lipoxygenase activity. The emergence on the cell surface of a threshold concentration of oxidized phospholipids, principally phosphatidylserine, signals recognition by the CD36 macrophage receptor.
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Affiliation(s)
- C R Kiefer
- Department of Hospital Laboratories/Clinical Pathology, UMASS Memorial Medical Center, Worcester, Massachusetts 01605, USA
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21
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Innes DS, Sinard JH, Gilligan DM, Snyder LM, Gallagher PG, Morrow JS. Exclusion of the stomatin, alpha-adducin and beta-adducin loci in a large kindred with dehydrated hereditary stomatocytosis. Am J Hematol 1999; 60:72-4. [PMID: 9883810 DOI: 10.1002/(sici)1096-8652(199901)60:1<72::aid-ajh13>3.0.co;2-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Defects in stomatin, alpha-adducin, and beta-adducin have been implicated in erythrocyte disorders of cation permeability. We performed linkage analysis of the genetic loci for these proteins in a large kindred with xerocytosis (dehydrated hereditary stomatocytosis). Using polymerase chain reaction-based genotyping techniques, all three loci are excluded as disease gene candidates.
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Affiliation(s)
- D S Innes
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06520-8023, USA
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22
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Kiefer CR, McKenney JB, Trainor JF, Lambrecht RW, Bonkovsky HL, Lifshitz LM, Valeri CR, Snyder LM. Porphyrin loading of lipofuscin granules in inflamed striated muscle. Am J Pathol 1998; 153:703-8. [PMID: 9736020 PMCID: PMC1853029 DOI: 10.1016/s0002-9440(10)65613-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/30/1998] [Indexed: 11/15/2022]
Abstract
To further the understanding of oxidative effects on inflammation injury to muscle fiber structure, fluorescent imaging analysis of human striated muscle tissues from a variety of inflammatory or postinflammatory etiologies was undertaken in a search for accumulated coproporphyrin, a red autofluorescent byproduct of heme biosynthesis that would theoretically be formed under oxidative insult. Using a differential excitation method of in situ analysis, porphyrin autofluorescence was detected in intact fibers within the context of the yellow autofluorescent subsarcolemmal lipofuscin granules. Relative measurements of porphyrin concentration in the granules from different patients indicated that the acute/subacute inflammatory specimens grouped significantly higher than the more chronic inflammatory and nonpathological specimens. Myoglobin was also found to be associated with the granules. Myoglobin heme iron could potentially serve as a Fenton reagent for the intracellular generation of hydroxyl radicals, which are responsible for the oxidation of the porphyrinogens. High-performance liquid chromatography analysis of extracted dense particles revealed coproporphyrin as the sole porphyrin present. The observation of coproporphyrin within lipofuscin granules, previously unreported, suggests that lipofuscin accumulation in striated muscle may begin under conditions of acute oxidative stress, as marked by the oxidation of extramitochondrial porphyrinogens that are immediately incorporated into the granules.
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Affiliation(s)
- C R Kiefer
- Department of Hospital Laboratories/Clinical Pathology, University of Massachusetts Medical Center, Worcester, USA.
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23
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Kuypers FA, Yuan J, Lewis RA, Snyder LM, Kiefer CR, Bunyaratvej A, Fucharoen S, Ma L, Styles L, de Jong K, Schrier SL. Membrane phospholipid asymmetry in human thalassemia. Blood 1998; 91:3044-51. [PMID: 9531618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Phospholipid asymmetry in the red blood cell (RBC) lipid bilayer is well maintained during the life of the cell, with phosphatidylserine (PS) virtually exclusively located in the inner monolayer. Loss of phospholipid asymmetry, and consequently exposure of PS, is thought to play an important role in red cell pathology. The anemia in the human thalassemias is caused by a combination of ineffective erythropoiesis (intramedullary hemolysis) and a decreased survival of adult RBCs in the peripheral blood. This premature destruction of the thalassemic RBC could in part be due to a loss of phospholipid asymmetry, because cells that expose PS are recognized and removed by macrophages. In addition, PS exposure can play a role in the hypercoagulable state reported to exist in severe beta-thalassemia intermedia. We describe PS exposure in RBCs of 56 comparably anemic patients with different genetic backgrounds of the alpha- or beta-thalassemia phenotype. The use of fluorescently labeled annexin V allowed us to determine loss of phospholipid asymmetry in individual cells. Our data indicate that in a number of thalassemic patients, subpopulations of red cells circulate that expose PS on their outer surface. The number of such cells can vary dramatically from patient to patient, from as low as that found in normal controls (less than 0.2%) up to 20%. Analysis by fluorescent microscopy of beta-thalassemic RBCs indicates that PS on the outer leaflet is distributed either over the entire membrane or localized in areas possibly related to regions rich in membrane-bound alpha-globin chains. We hypothesize that these membrane sites in which iron carrying globin chains accumulate and cause oxidative damage, could be important in the loss of membrane lipid organization. In conclusion, we report the presence of PS-exposing subpopulations of thalassemic RBC that are most likely physiologically important, because they could provide a surface for enhancing hemostasis as recently reported, and because such exposure may mediate the rapid removal of these RBCs from the circulation, thereby contributing to the anemia.
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Affiliation(s)
- F A Kuypers
- Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
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24
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Bell J, Ash DE, Snyder LM, Kulathila R, Blackburn NJ, Merkler DJ. Structural and functional investigations on the role of zinc in bifunctional rat peptidylglycine alpha-amidating enzyme. Biochemistry 1997; 36:16239-46. [PMID: 9405058 DOI: 10.1021/bi970903d] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Bifunctional peptidylglycine alpha-amidating enzyme (alpha-AE) catalyzes the two-step conversion of C-terminal glycine-extended peptides to C-terminal alpha-amidated peptides and glyoxylate. The first step is the ascorbate-, O2-, and copper-dependent hydroxylation of the alpha-carbon of the glycyl residue, producing an alpha-hydroxyglycine-extended peptide. The second step is the ascorbate-, O2-, and copper-independent dealkylation of the carbinolamide intermediate. We show that alpha-AE requires 1.1 +/- 0. 2 mol of zinc/mol of enzyme for maximal (S)-N-dansyl-Tyr-Val-alpha-hydroxyglycine dealkylation activity. Treatment of the enzyme with EDTA abolishes both the peptide hydroxylation and the carbinolamide dealkylation activities. Addition of Zn(II), Co(II), Cd(II), and Mn(II) partially restores carbinolamide dealkylation activity to the EDTA-treated enzyme. Addition of Co(II) produces the greatest restoration of dealkylation activity, 32% relative to a control not treated with EDTA, while Mn(II) addition results in the smallest restoration of dealkylation activity, only 3% relative to an untreated control. The structure and coordination of the zinc center has been investigated by X-ray absorption spectroscopy. EXAFS data are best interpreted by an average coordination of 2-3 histidine ligands and 1-2 non-histidine O/N ligands. Since catalytic zinc centers in other zinc metalloenzymes generally exhibit only O/N ligands to the zinc atom, a zinc-bound water or hydroxide may serve as a general base for the abstraction of the hydroxyl proton from the carbinolamide intermediate. Alternatively, the zinc may function in a structural role.
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Affiliation(s)
- J Bell
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282, USA
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25
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Waugh RE, McKenney JB, Bauserman RG, Brooks DM, Valeri CR, Snyder LM. Surface area and volume changes during maturation of reticulocytes in the circulation of the baboon. J Lab Clin Med 1997; 129:527-35. [PMID: 9142049 DOI: 10.1016/s0022-2143(97)90007-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Changes in the surface area and volume of reticulocytes were measured in vivo during late stage maturation. Baboons were treated with erythropoietin to produce mild reticulocytosis. Reticulocyte-rich cohorts of cells were obtained from whole blood by density gradient centrifugation. The cohorts were labeled with biotin, reinfused into the animal, and recovered from whole blood samples by panning on avidin supports. Changes in the surface area, volume, and membrane deformability were measured using micropipettes during the 2 to 6 weeks subsequent to reinfusion. For the entire cohort, the membrane area decreased by 10% to 15% and the cell volume decreased by approximately 8.5%, mostly within 24 hours after reinfusion. Estimates of the cellular dimensions of the reticulocyte subpopulation within this cohort indicated larger reductions in the mean cell area (12% to 30%) and mean cell volume (approximately 15%) of the reticulocytes themselves. Two weeks after reinfusion, the distribution of cell size for the cohort was indistinguishable from that of whole blood. There was evidence of slightly elevated membrane shear rigidity in some reticulocytes before reinfusion, but this slight increase disappeared within 24 hours after reinfusion. These are the first direct measurements of changes in the membrane physical properties of an identifiable cohort of reticulocytes as they mature in vivo.
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Affiliation(s)
- R E Waugh
- Department of Biophysics, University of Rochester School of Medicine and Dentistry, New York 14642, USA
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26
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Schrier SL, Bunyaratvej A, Khuhapinant A, Fucharoen S, Aljurf M, Snyder LM, Keifer CR, Ma L, Mohandas N. The unusual pathobiology of hemoglobin constant spring red blood cells. Blood 1997; 89:1762-9. [PMID: 9057661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Hemoglobin Constant Spring (HbCS) is the most common nondeletional alpha-thalassemic mutation and is an important cause of HbH-like disease in Southeast Asia. HbCS variants have an almost normal mean cell volume (MCV) and the anemia is more severe when compared with other alpha-thalassemic variants. We explored the pathobiology of HbCS red blood cells (RBCs) because the underlying cause(s) of this MCV "normalizing" effect of HbCS and the more severe anemia are not fully explained. HbCS containing RBCs are distinctly overhydrated relative to deletional alpha-thalassemia variants, and the derangement of volume regulation and cell hydration occurs early in erythroid maturation and is fully expressed at the reticulocyte stage. Furthermore, the membrane rigidity and membrane mechanical stability of HbCS containing RBCs is increased when compared with HbH and alpha-thalassemia-1 trait RBCs. In seeking the cause(s) underlying these cellular alterations we analyzed membranes from HbCS and deletional alpha-thalassemic variants and found that in addition to oxidized beta-globin chains, oxidized alpha cs-globin chains are also associated with the membranes and their skeletons in HbCS containing RBCs. We propose that the membrane pathology of HbCS variants is caused by combination of the deleterious effects induced by membrane-bound oxidized alpha cs- and beta-globin chains. The membrane alterations induced by alpha cs chains are more akin to those induced by beta A-globin chains than those induced by the alpha A-globin chains that accumulate in the beta-thalassemias. Thus, each globin chain, alpha cs, alpha A, beta A, appears to produce its own form of membrane perturbation.
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Affiliation(s)
- S L Schrier
- Division of Hematology, Stanford University, CA, USA
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27
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Lieberthal W, McKenney JB, Kiefer CR, Snyder LM, Kroshian VM, Sjaastad MD. Beta1 integrin-mediated adhesion between renal tubular cells after anoxic injury. J Am Soc Nephrol 1997; 8:175-83. [PMID: 9048335 DOI: 10.1681/asn.v82175] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
beta 1 integrin-mediated adhesion between renal tubular cells after anoxic injury. This study examined the effect of sublethal injury, induced by ATP depletion (5 mM cyanide in the absence of dextrose), on the distribution and function of beta 1 integrins in primary cultures of mouse proximal tubular (MPT) cells. It was shown in this study that sublethal injury results in loss of focal contacts present in uninjured MPT cells, and that the beta 1 integrin molecule becomes redistributed to the apical membrane domain of sublethally injured cells. Polystyrene beads coated with Arg-Gly-Asp (RGD)-containing peptide adhere to the surface of sublethally injured MPT cells but not to control, dextrose-treated cells, indicating that the beta 1 integrins present on the apical surface of the cell remain functional. The presence of an excess of free RGD-containing peptide reduces binding of RGD-coated beads to sublethally injured MPT cells by approximately 50%. It was also demonstrated that adherence of MPT cells in suspension to cyanide-treated monolayers is increased more than 300% above adhesion to control, uninjured monolayers. This abnormal cell-cell adhesion is ameliorated by the presence of an excess of RGD-containing peptide and is reversed if cyanide-treated cells are allowed to recover for 1 h. It was concluded that the beta 1 integrin becomes expressed on the apical surface of MPT cells after sublethal injury. These apically expressed integrins remain functional and mediate aberrant adhesion between MPT cells.
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Affiliation(s)
- W Lieberthal
- Renal Section, Boston University Medical Center Hospital, MA 02118, USA
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28
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Jarolim P, Murray JL, Rubin HL, Taylor WM, Prchal JT, Ballas SK, Snyder LM, Chrobak L, Melrose WD, Brabec V, Palek J. Characterization of 13 novel band 3 gene defects in hereditary spherocytosis with band 3 deficiency. Blood 1996; 88:4366-74. [PMID: 8943874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Hereditary spherocytosis (HS) is a common hemolytic anemia of variable clinical expression. Pathogenesis of HS has been associated with defects of several red cell membrane proteins including erythroid band 3. We have studied erythrocyte membrane proteins in 166 families with autosomal dominant HS. We have detected relative deficiency of band 3 in 38 kindred (23%). Band 3 deficiency was invariably associated with mild autosomal dominant spherocytosis and with the presence of pincered red cells in the peripheral blood smears of unsplenectomized patients. We hypothesized that this phenotype is caused by band 3 gene defects. Therefore, we screened band 3 DNA from these 38 kindred for single strand conformational polymorphisms (SSCP). In addition to five mutations detected previously by SSCP screening of cDNA, we detected 13 new band 3 gene mutations in 14 kindred coinherited with HS. These novel mutations consisted of two distinct subsets. The first subset included seven nonsense and frameshift mutations that were all associated with the absence of the mutant mRNA allele from reticulocyte RNA, implicating decreased production and/or stability of mutant mRNA as the cause of decreased band 3 synthesis. The second group included five substitutions of highly conserved amino acids and one in-frame deletion. These six mutations were associated with the presence of comparable levels of normal and mutant band 3 mRNA. We suggest that these mutations interfere with band 3 biosynthesis leading thus to the decreased accumulation of the mutant band 3 allele in the plasma membrane.
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Affiliation(s)
- P Jarolim
- Department of Biomedical Research, St Elizabeth's Medical Center, Tufts University School of Medicine, Boston, MA, USA
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29
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Aljurf M, Ma L, Angelucci E, Lucarelli G, Snyder LM, Kiefer CR, Yuan J, Schrier SL. Abnormal assembly of membrane proteins in erythroid progenitors of patients with beta-thalassemia major. Blood 1996; 87:2049-56. [PMID: 8634456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The life threatening anemia in beta-thalassemia major (Cooley's anemia) is characterized by profound intramedullary lysis, the cause of which is incompletely understood. Using marrow obtained from beta thalassemia major patients undergoing allogeneic bone marrow transplantation in Pesaro Italy, it became possible to directly study the mechanism of the intramedullary hemolysis. Based on our previous studies, we hypothesized that the unmatched alpha globin chains would interfere with normal assembly of erythroid precursor membrane proteins. Patient and control erythroid precursors were reacted with monospecific polyclonal rabbit antibodies directed against spectrin, band 3, and band 4.1 and with a monoclonal anti-alpha globin chain antibody. Using laser confocal fluorescence microscopy, normal erythroid precursors show no alpha globin chain accumulation and exhibited uniformly smooth rim fluorescence of the three membrane proteins. In some thalassemic precursors, spectrin appeared to interact with large alpha globin accumulations, and in many of these cells the spectin appeared clumped and discontinuous. Band 4.1 interacted strongly with accumulations of alpha globin in thalassemic precursors to produce bizarrely clumped zones of abnormal band 4.1 distribution. Band 3 was incorporated smoothly into thalassemic erythroblast membranes. However, the proerythroblasts and basophilic erythroblasts were significantly deficient in band 3. Thus, accumulations of alpha globin in beta-thalassemia major colocalized with and disrupt band 4.1 and spectrin assembly into the membrane. The cause of deficient band 3 incorporation into thalassemic proerythroblast membranes remains unknown. These profound membrane alterations would likely contribute to the intramedullary lysis seen in Cooley's anemia.
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Affiliation(s)
- M Aljurf
- Division Ematologica Di Muraglia, Centro Trapianto Di Midollo Osseo, Pesaro, Italy
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30
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Patiño-Sarcinelli F, Knecht H, Pechet L, Pihan G, Savas L, Snyder LM. Leukemia with megakaryocytic differentiation following essential thrombocythemia and myelofibrosis. Case report and review of the literature. Acta Haematol 1996; 95:122-8. [PMID: 8638441 DOI: 10.1159/000203860] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Leukemias of megakaryocytic lineage are rare and heterogeneous clinical entities. The nomenclature published in the literature is confusing and perhaps inappropriate to designate these primary myeloproliferative disorders. We describe a patient with essential thrombocythemia who evolved through myelofibrosis and myeloid metaplasia to a final picture of leukemia with megakaryocytic differentiation in the peripheral blood. This case illustrates different aspects of a chronic myeloproliferative disorder where myelofibrosis and myeloid metaplasia are frequent but secondary events. We have reviewed the literature focusing on the role of clonal megakaryocytic proliferation in myelofibrosis and on the clinical characterization of leukemia with megakaryocytic phenotype. We also present our interpretation of the literature which indicates that a formal review of the nomenclature is urgently needed.
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Affiliation(s)
- F Patiño-Sarcinelli
- Division of Hematology-Oncology, University of Massachusetts Medical Center, Worcester 01665, USA
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31
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Kiefer CR, Trainor JF, McKenney JB, Valeri CR, Snyder LM. Hemoglobin-spectrin complexes: interference with spectrin tetramer assembly as a mechanism for compartmentalization of band 1 and band 2 complexes. Blood 1995; 86:366-71. [PMID: 7795245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The irreducible complexation of hemoglobin with spectrin is a natural phenomenon of red blood cell aging, positively correlating with increasing cell density and decreasing cell deformability. The current study begins to address the role of these complexes in the disruption of membrane skeletal physiology and structure. The effect of bound hemoglobin on spectrin dimer self-association was investigated in vitro. The extent of conversion of isolated spectrin dimers to tetramers was evaluated as a function of peroxide-induced globin complexation before the conversion incubations. The incremental accumulation of tetramer was observed to decrease with increasing peroxide concentration used in the globin complexation step. The role of oxidized heme in this process was made apparent by the inability of carboxyhemoglobin to inhibit tetramer accumulation. A Western blot analysis of naturally formed globin-spectrin conjugates demonstrated irreducible complexes of globin with both bands 1 and 2. The complexes are tentatively designated "h1" and "h2". This analysis also demonstrated that h1 is completely extractable from cell ghosts, whereas h2 is only 50% extractable. These findings are incorporated into a hypothesis linking globin-spectrin complexation and the consequent inhibition of spectrin dimer self-association to the clustered band 3 senescence antigen (Low et al, Science 227:531, 1985).
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Affiliation(s)
- C R Kiefer
- Department of Immunology and Microbiology, Medical College of Georgia, Augusta, USA
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32
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Nardella A, Pechet L, Snyder LM. Continuous improvement, quality control, and cost containment in clinical laboratory testing. Effects of establishing and implementing guidelines for preoperative tests. Arch Pathol Lab Med 1995; 119:518-22. [PMID: 7605167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE To develop guidelines for laboratory tests ordered before admission for elective surgery. DESIGN A seven-step continuous quality improvement process. SETTING The Departments of Laboratory Medicine, Surgery, and Anesthesia of the University of Massachusetts Medical Center, a 384-bed, teaching, tertiary-care facility. PARTICIPANTS Core group of the Department of Laboratory Medicine and the Laboratory Medical Advisory Committee. INTERVENTION Guidelines were developed for laboratory tests ordered before elective surgery. They were divided into four major groups as well as by age and gender. After an intense educational effort, consent was obtained from the majority of surgeons, who agreed to delegate the ordering of tests to the nurses and anesthesiologists who examine patients before surgery. MAIN OUTCOME MEASURE Charts chosen at random by the medical records department for the period prior to implementation of guidelines were reviewed and compared with records 1 and 2 years later. RESULTS Reductions of 50% and 60% in the first and second years, respectively, in the overall number of tests ordered per patient were demonstrated. An improvement in the appropriateness of tests was also documented: 81% in the first year and 86% in the second year, compared with 65% appropriateness prior to implementation of guidelines. A 1-year savings of $66,981 and an overall 2-year savings of $75,995 were documented. CONCLUSIONS We have described an approach that involves a sustained educational effort and collaboration of nurses and physicians and have presented specific guidelines for preoperative testing. A major decrease in the number of tests ordered, an increase in their appropriateness, and marked fiscal savings were documented.
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Affiliation(s)
- A Nardella
- Department of Hospital Laboratories, University of Massachusetts Medical Center, Worcester 01655, USA
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33
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Griffiths EB, Pechet L, Snyder LM. A laboratory rotation for medical house officers. Bridging the gap. Arch Pathol Lab Med 1995; 119:480-2. [PMID: 7748080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In an attempt to improve physicians' laboratory practice behavior, the Department of Hospital Laboratories at the University of Massachusetts Medical Center developed a rotation for first year housestaff. Medical interns were chosen for this pilot program because they are the most frequent users of our laboratory facilities. Rotations provide an overview of the laboratory organization, quality control and assurance, appropriate use of laboratory testing, cost containment, and an introduction to different laboratory disciplines. As assessed by discussions during an interview following completion of the program, the participants have shown an increased understanding of how a modern hospital laboratory functions and of the complexity of services provided. The respect for the laboratory staff and confidence in test results issued have increased, and house officers are more likely to use laboratory services in a more cost-efficient manner.
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Affiliation(s)
- E B Griffiths
- Department of Hospital Laboratories and Clinical Pathology, University of Massachusetts Medical Center, Worcester 01655, USA
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34
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Collins K, Quinlan A, Farrell M, Snyder LM. Influencing physician behavior with CQI: a case study. Qual Manag Health Care 1995; 2:27-35. [PMID: 10135581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Health care reform will require unprecedented levels of cooperation among physicians, health care administrators, and other providers in order to ensure high-quality, affordable care for all. At the University of Massachusetts Medical Center, CQI techniques helped engage physicians in an effort to substantially alter ordering patterns to cut costs and achieve quality goals.
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35
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Nardella A, Farrell M, Pechet L, Snyder LM. Continuous improvement, quality control, and cost containment in clinical laboratory testing. Enhancement of physicians' laboratory-ordering practices. Arch Pathol Lab Med 1994; 118:965-8. [PMID: 7944897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In 1991, the University of Massachusetts Medical Center, in Worcester, developed a model for change by using a program of continuous quality improvement to enhance physicians' laboratory-ordering practices, particularly the test for bleeding times. We describe a model that was developed through a seven-step continuous quality improvement process, and we discuss our success in increasing the appropriateness of ordering the tests for bleeding times while significantly reducing the costs for patients and hospitals. The following factors contributed to the program's success: an advisory structure; presentations to the medical staff; focused feedback sessions; and most important, well-documented guidelines with institutional support for new behavior.
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Affiliation(s)
- A Nardella
- Hospital Laboratories, University of Massachusetts Medical Center, Worcester 01655
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36
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Kulathila R, Consalvo AP, Fitzpatrick PF, Freeman JC, Snyder LM, Villafranca JJ, Merkler DJ. Bifunctional peptidylglcine alpha-amidating enzyme requires two copper atoms for maximum activity. Arch Biochem Biophys 1994; 311:191-5. [PMID: 8185317 DOI: 10.1006/abbi.1994.1225] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The conversion of C-terminal glycine-extended peptides to C-terminal alpha-amidated peptides occurs in two distinct reactions, both of which are catalyzed by bifunctional peptidylglycine alpha-amidating enzyme. The first step is the alpha-hydroxylation of the C-terminal glycine residue and the second step is the dealkylation of the alpha-hydroxyglycine-extended peptide to the alpha-amidated peptide and glyoxylate. We show that the bifunctional enzyme requires 1.9 +/- 0.2 mol of copper/mol of enzyme for maximal dansyl-Tyr-Lys-Gly amidation activity under the conditions of high enzyme concentration (approximately 80 microM) required to measure initial rates for this poor substrate. The enzyme, as purified, contains a substoichiometric amount of copper and has only trace levels of amidation activity. Addition of exogenous Cu(II) ions stimulates amidation activity approximately 3000-fold at the optimum copper stoichiometry and the enzyme is then inhibited by excess Cu(II). No stimulation of amidation activity is observed upon the addition of the following divalent metal ions: Mn(II), Fe(II), Ni(II), Cd(II), and the oxovanadium cation, VO(II). The enzyme-catalyzed dealkylation of alpha-hydroxyhippuric acid to benzamide shows no dependence on copper, indicating that the copper dependence of the amidation reaction must be attributed to a copper dependence in peptide alpha-hydroxylation.
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Affiliation(s)
- R Kulathila
- Analytical Protein and Organic Chemistry Group, Unigene Laboratories, Inc., Fairfield, New Jersey 07004
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37
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Yuan J, Angelucci E, Lucarelli G, Aljurf M, Snyder LM, Kiefer CR, Ma L, Schrier SL. Accelerated programmed cell death (apoptosis) in erythroid precursors of patients with severe beta-thalassemia (Cooley's anemia). Blood 1993; 82:374-7. [PMID: 8329696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The profound and life-threatening anemia in patients with Cooley's anemia is ascribed primarily to intramedullary hemolysis (ineffective erythropoiesis), the cause of which is obscure. Based on prior morphologic data showing nuclear abnormalities, we hypothesized that accelerated apoptosis could occur in these erythroid precursors. The highly successful bone marrow (BM) transplantation program for patients with Cooley's anemia provided us with a unique opportunity to test this hypothesis. We obtained pretransplantation BM aspiration samples from patients undergoing BM transplantation in Pesaro, Italy and from their allogeneic donors. The erythroid precursors were isolated using ficoll sedimentation and then panning selecting fro CD45- cells. Cytospin and Giemsa staining showed that the separation provided greater than 90% erythroblasts. Five million of these erythroblasts were lysed and their DNA was isolated. There were obvious ladder patterns of DNA breakdown products in beta-thalassemia major samples, with less occurring in beta-thalassemia trait. Normal individuals showed only a slight smear of breakdown of DNA. These results indicate there is enhanced apoptosis in the erythroblasts in the BMs of Cooley's anemia patients. This finding might partially explain why most of these erythroblasts never survive to become mature erythrocytes.
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Affiliation(s)
- J Yuan
- Divisione Ematologica di Muraglia, Centro Trapianto di Midollo Osseo, Ospedale Di Pesaro, Italy
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38
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Abstract
Prolonged arterial infusions of cisplatin (DDP) have been effective in the treatment of regionally confined malignancies. It is unclear whether the route or schedule of DDP administration was responsible for the observed therapeutic benefit. To resolve this issue, tumor and normal tissue platinum (Pt) levels were determined in rats bearing hind-limb rat mammary tumors after intravenous (IV) and intra-arterial (IA) DDP infusions of constant dose and varying lengths. Infusions of DDP at 6 mg/kg were conducted IA over 30 minutes, and 3, 6, 24, and 48 hours and IV over 30 minutes and 48 hours. After infusion, Pt concentrations in solubilized tissue homogenates were measured by flameless atomic absorption spectroscopy. Maximum tumor Pt levels were seen after 48-hour IA infusion (29.3 micrograms Pt/mg tissue). IA infusions of 24 hours or less resulted in significantly lower Pt levels. Maximum tumor Pt concentration after IV administration was only 0.98 micrograms/mg tissue (48-hour infusion). Muscle Pt levels adjacent to the tumor were highest in the IA infused extremities, but at the 48-hour interval, were 53-fold less than tumor levels. Tumor and adjacent muscle Pt levels were not significantly different from each other after IV administration. This study provides pharmacologic evidence that lengthening the duration of IA DDP infusion increases tumor levels of Pt over that of IV or rapid IA administrations. The benefit of prolonged IA DDP infusions is dependent upon both route and schedule of drug administration.
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Affiliation(s)
- J G Jakowatz
- Department of Surgery, University of California Irvine, Orange
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39
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Abstract
Experiments are described that have lead to the development of a highly reproducible tryptic map of recombinant DNA derived bovine somatotropin (rbSt). Tryptic digestion of rbSt at 37 degrees C results in the formation of a precipitate. Preliminary characterization of the precipitate suggests that its formation is due to the association of intermediate tryptic fragments. An examination of the temperature dependence of the digestion has revealed that precipitate formation is inhibited when digestion is performed at 10 degrees C or less. The combination of a 5-mg sample, the use of highly purified trypsin, and digestion at 5 degrees C generate a tryptic map that exhibits an average 1.3% RSD (0.5-3.6%) for all anticipated fragments. Validation studies demonstrate that while the peak response precision is rugged to daily variation of operators or chromatographic systems, the fragment retention is not. This dictates that peaks be assigned by qualitative pattern recognition. Assay ruggedness in the peak response domain allows for the implementation of quantitative methods for the comparison of rbSt reference standard and sample tryptic maps. The assay is linear for all anticipated fragments within 50-150% of the operating range. Specificity is established by assay of pituitary somatotropins from other species and rbSt analogs produced by site-specific mutagenesis. The data demonstrate that all single amino acid substitutions examined are identified by using the technique. Assay sensitivity is validated for selected tryptic fragments through analysis of reference standard digests spiked with known amounts of rbSt analog digests. The data indicate that potential impurities of 3.2, 2.0, and 4.5% can be quantitated with statistical confidence in the tryptic fragments T1, T10, and T23 + 25, respectively.
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Affiliation(s)
- J J Dougherty
- Biotechnology and Spectroscopy Development, Upjohn Company, Kalamazoo, Michigan 49001
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40
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McKenney J, Valeri CR, Mohandas N, Fortier N, Giorgio A, Snyder LM. Decreased in vivo survival of hydrogen peroxide-damaged baboon red blood cells. Blood 1990; 76:206-11. [PMID: 2364171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In this study we attempt to establish the consequence of in vitro hydrogen peroxide (H2O2)-induced membrane damage as manifested by spectrin-hemoglobin (Sp-Hb) complex formation and decreased red blood cell (RBC) deformability to in vivo RBC survival in baboons. After exposure to 135 to 581 mumols/L H2O2 and reduction with dithiothreitol (DTE), baboon RBCs were infused into the animal, and the fraction of cells remaining in circulation after 24 hours and the lifespan of surviving cells were quantitated. In a dose-dependent fashion, a positive correlation was observed between in vitro membrane alterations and the 24-hour in vivo survival. While 12% of the control cells were removed from circulation in 24 hours, 23% were removed after treatment with 339 mumols/L H2O2, and 36% following exposure to 581 mumols/L H2O2. Pretreatment with carbon monoxide before exposure with H2O2 increased the survival of oxidized RBCs. RBCs not removed from circulation in the first 24 hours had a normal lifespan. Moreover, by selectively isolating biotin-labeled, peroxide-treated cells that survived the first 24-hour posttransfusion period, a significant decrease in Sp-Hb crosslinking was observed in these cells. These results suggest that a subpopulation of cells sensitive to oxidation were removed during the first 24 hours. To identify this population, the survival of density-fractionated RBCs exposed to oxidant stress was quantitated. No differences in either the 24-hour survival or RBC life span were observed between untreated low-density (MCHC less than or equal to 32g/dL) and high-density cells (MCHC greater than or equal to 37g/dL). However, striking differences were noted after treatment with 339 mumols/L H2O2, with the 24-hour survival of high-density cells showing a marked decrease compared with low-density cells. These data support our hypothesis that during peroxidative membrane damage, Hb oxidation initiates a sequence of events resulting in skeletal changes that lead to membrane alterations and, eventually, in vivo destruction, and that the dense, dehydrated cells are more susceptible to oxidant damage.
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Affiliation(s)
- J McKenney
- Division of Hematology, St Vincent Hospital, Worcester, MA 01604
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Abstract
This study was done to determine whether hereditary spherocytosis (HS) red blood cells (RBC) have decreased amounts of Rh antigens. Initially we studied the RBC of five members of one family, two of whom had HS. Using automated quantitative haemagglutination tests, we demonstrated that HS RBC agglutinated less with Rh antisera of four specificities than did normal RBC, indicating that Rh antigens are decreased on HS RBC. In this family, the strength of other blood group antigens on HS RBC was estimated by manual titres and agglutination scores. No appreciable differences in the agglutination of HS and normal RBC were observed with non-Rh antisera. To assess the strength of the D antigen more accurately, the number of D sites was quantitated on the RBC of 19 individuals with HS and 11 of their healthy relatives. HS RBC had 9209 +/- 4084 (mean +/- SD) D sites, whereas the normal RBC had 15 394 +/- 5763 D sites. These two means were significantly different (P less than 0.01). HS RBC were also compared to normal RBC of unrelated individuals who had the same Rh phenotype. These analyses showed that HS RBC had about half of the normal number of D sites. Our data indicate that HS red cells have decreased amount of the Rh antigen D and probably also of other Rh antigens.
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Affiliation(s)
- I O Szymanski
- University of Massachusetts Medical Center, Worcester 01655
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Sheerin HE, Snyder LM, Fairbanks G. Cation transport in oxidant-stressed human erythrocytes: heightened N-ethylmaleimide activation of passive K+ influx after mild peroxidation. Biochim Biophys Acta 1989; 983:65-76. [PMID: 2758051 DOI: 10.1016/0005-2736(89)90381-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Normal and chronically dehydrated (hereditary xerocytosis) human red cells were subjected to mild peroxidative treatment (315 microM hydrogen peroxide (H2O2), 15 min) in the presence of azide. The subsequent expression of passive (ouabain-resistant) K+ transport activities was analyzed by measurement of 86Rb+ influx. Peroxidation of normal red cells did not affect basal K+ transport activity, but the increment in K+ influx elicited by 0.5 mM N-ethylmaleimide (NEM) was increased 3-fold. The enhanced K+ influx was chloride-dependent, but only partially inhibited by 0.1 mM furosemide. Stimulated activity declined progressively after NEM activation, but could be restored by a second NEM treatment. Prior conversion of hemoglobin to the carbonmonoxy form abolished the response to peroxide, while 200 microM butylated hydroxytoluene (BHT) exerted only partial inhibition, suggesting that the effect of H2O2 requires interaction of activated, unstable hemoglobin species with the membrane, but that lipid peroxidation is not sufficient. Peroxidation following NEM treatment also enhanced NEM activation, indicating that enhancement does not require altered NEM reactions with stimulatory or inhibitory sites. Passive K+ transport in hereditary xerocytosis red cells was not activated by NEM, with or without H2O2 pretreatment. The results demonstrate that modest peroxidative damage to red cells can heighten the activation of a transport system that is thought to be capable of mediating net K+ efflux and volume reduction in cells that express it. Models are proposed in which the effects of NEM, H2O2, cell swelling and other factors are mediated by conformational changes in a postulated subpopulation of anion channel (Band 3) molecules that bind the K+ transporter.
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Affiliation(s)
- H E Sheerin
- Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, MA
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Willey P, Snyder LM. Canid modification of human remains: implications for time-since-death estimations. J Forensic Sci 1989; 34:894-901. [PMID: 2760591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Time-since-death estimations are usually based on physical decomposition of the corpse, insect succession, and contextual associations. The rates of change and succession are based on decomposition studies, most of which control access of scavengers to the corpse; however, many naturally exposed corpses are subject to scavenger modification. These modifications change the rate of decomposition, the pattern of insect succession, and the context of associations, thus altering estimations of time since death. A controlled feeding study with captive wolves and road-killed deer is pertinent to understanding canid scavenging and how scavenging may alter postmortem changes. During feeding, the wolves commonly dismember and devour the deer in a predictable sequence. Although there are some variations in the usual sequence, the carcass is always moved, and skeletal elements are separated, diminished in size and scattered. Scavenging must, therefore, be considered in estimating time since death.
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Affiliation(s)
- P Willey
- Department of Anthropology, University of Tennessee, Knoxville
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Snyder LM, Kar R, Wile AG. Plasma ultrafiltration as successful therapy of rabbit VX-2 carcinoma. J Surg Oncol 1988; 39:165-8. [PMID: 3184952 DOI: 10.1002/jso.2930390306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
It has been demonstrated that tumor-bearing animals elaborate a low molecular weight (less than 10,000 daltons) factor capable of inhibiting in vitro lymphocyte function. It was postulated that removal of this factor would have a favorable effect on host immune response that would translate into improved tumor control. A study was conducted in rabbits bearing the VX-2 carcinoma. Ultrafiltration (UF) was performed 10 days following IV tumor inoculation. UF was achieved by passing blood through an Amicon Diafilter (molecular weight cutoff 10 kD) positioned between the arterial and venous cannulae after heparinization. Two plasma volumes of ultrafiltrate were removed with continuous saline replacement. Two groups of animals received the nonspecific immunoadjuvant, Detox, at time of therapy. Survival in the UF group (N = 9) was compared to untreated tumor-bearing animals (N = 10), sham-operated animals (N = 6), animals receiving Detox (N = 7), and animals receiving UF plus Detox (N = 6). UF imparted a survival advantage when compared to controls (mean 35 days vs. 25 days, P less than .01). The sham group had survival identical to controls. Detox alone conferred minimal survival advantage (mean 29 days, P greater than .05). However, UF + Detox demonstrated maximal survival benefit (mean 40 days, P less than .01). We conclude that UF is an effective anticancer modality in this preclinical model. This study suggests that efforts aimed at eliminating suppressor molecules in cancer patients may be of benefit, especially when combined with biological response modifiers such as Detox.
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Affiliation(s)
- L M Snyder
- Department of Surgery, University of California, Irvine Medical Center, Orange 92668
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Fortier N, Snyder LM, Garver F, Kiefer C, McKenney J, Mohandas N. The relationship between in vivo generated hemoglobin skeletal protein complex and increased red cell membrane rigidity. Blood 1988; 71:1427-31. [PMID: 3359048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In vitro induced oxidative damage to normal human RBCs has previously been shown to result in increased membrane rigidity as a consequence of the generation of a protein complex between hemoglobin and spectrin. In order to determine if in vivo generated hemoglobin-spectrin complexes may play a role in increased membrane rigidity of certain pathologic red cells, we measured both these parameters in membranes prepared from hereditary xerocytosis (Hx), sickle cell disease (Sc), and red cells from thalassemia minor (beta thal). Membranes were prepared from density-fractionated red cells, and membrane deformability was measured using an ektacytometer. Hemoglobin-spectrin complex was determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel analysis, as well as by Western blot analysis using a monoclonal antibody against the beta-subunit of hemoglobin. For these three types of pathologic red cells, progressive cellular dehydration was associated with increased membrane rigidity and increased content of hemoglobin-spectrin complex. Moreover, the increase in membrane rigidity appeared to be directly related to the quantity of hemoglobin-spectrin complex associated with the membrane. Our findings imply that hemoglobin-spectrin complex is generated in vivo, and this in turn results in increased membrane rigidity of certain pathologic red cells. The data further suggest that oxidative crosslinking may play an important role in the pathophysiology of certain red cell disorders.
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Affiliation(s)
- N Fortier
- Department of Hematology, St. Vincent Hospital, Worcester, MA 01604
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Snyder LM, Fortier NL, Leb L, McKenney J, Trainor J, Sheerin H, Mohandas N. The role of membrane protein sulfhydryl groups in hydrogen peroxide-mediated membrane damage in human erythrocytes. Biochim Biophys Acta 1988; 937:229-40. [PMID: 3337802 DOI: 10.1016/0005-2736(88)90245-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The formation of spectrin-hemoglobin complex following treatment of red cells with hydrogen peroxide (H2O2) has previously been shown to be associated with alterations in cell shape, decreased membrane deformability and increased recognition of modified cells by anti-IgM immunoglobulin in a phagocytic assay by monocytes. Prior treatment with carbon monoxide completely inhibited the H2O2-associated membrane changes, indicating a role for oxidized hemoglobin in the complex formation. Also, in a cell-free system, blockage of sulfhydryl (SH) groups on purified spectrin by N-ethylmaleimide significantly reduced the complex formation, suggesting a role for SH groups of spectrin in crosslinking process. The present study was undertaken to examine the role of SH blockade by N-ethylmaleimide on intact red cells undergoing oxidative damage. Pretreatment of erythrocytes with N-ethylmaleimide at concentrations ranging from 0.1 to 0.2 mM resulted in decreased lipid peroxidation and spectrin hemoglobin crosslinking. Moreover, pretreatment with N-ethylmaleimide resulted in less marked alterations in cell shape and membrane deformability as well as reduced recognition of peroxidized cells by antiglobulin serum. N-Ethylmaleimide treatment had no effect on methemoglobin formation. Studies with 14C-labeled N-ethylmaleimide showed that over 50% of N-ethylmaleimide was incorporated into spectrin. Pretreatment of cells with higher concentrations of N-ethylmaleimide (over 0.2 mM) was associated with membrane dysfunction independent of H2O2. These results imply that blocking of reactive SH groups leads to reduced interaction of spectrin with oxidized globin. These data, along with our prior observations, indicate that SH groups on spectrin play an important role in hemoglobin oxidation-induced formation of spectrin-hemoglobin complex and the resultant deleterious effects on membrane properties.
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Affiliation(s)
- L M Snyder
- St. Vincent Hospital, Worcester, MA 01604
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Leb L, Snyder LM, Fortier NL, Andersen M. Antiglobulin serum mediated phagocytosis of normal senescent and oxidized RBC: role of anti-IgM immunoglobulins in phagocytic recognition. Br J Haematol 1987; 66:565-70. [PMID: 3499168 DOI: 10.1111/j.1365-2141.1987.tb01345.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Fresh human monocytes usually do not recognize normal RBCs; however, in our newly developed assay antiglobulin-opsonized normal RBCs were phagocytized. Both anti-IgG and anti-IgM fractions present in the antiglobulin serum were involved but the major opsonin was anti-IgM. The anti-IgM opsonized mainly senescent RBCs and therefore could be used to discriminate young from senescent RBCs. The antiglobulin serum and monospecific anti-IgM increased opsonization of in vitro oxidized and desialylated RBCs, whereas trypsin-treatment of RBCs decreased phagocytosis. The material removed by trypsin from the RBCs surface inhibited the antiglobulin and monospecific anti-IgM phagocytic assay supporting the view that membrane associated elements crossreacted with anti-IgM. These results suggest that both internal cellular events and external removal of sialic acid play a role in the emergence of non-IgG covered epitopes on the surface of senescent and oxidized erythrocytes.
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Affiliation(s)
- L Leb
- Division of Hematology, St Vincent Hospital, Worcester, Massachusetts 01604
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Snyder LM, Garver F, Liu SC, Leb L, Trainor J, Fortier NL. Demonstration of haemoglobin associated with isolated, purified spectrin from senescent human red cells. Br J Haematol 1985; 61:415-9. [PMID: 4063205 DOI: 10.1111/j.1365-2141.1985.tb02845.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Employing a direct and sensitive radioimmunoassay (RIA) we have confirmed the presence of haemoglobin associated with isolated, purified spectrin from senescent red cells. Haemoglobin associated with spectrin occurs in the highest amount in cells with an MCHC greater than 36 g/dl and is approximately 3% of the total spectrin extract. Spectrin from the young cells had the least haemoglobin, while an intermediate amount was found in unfractionated, whole red cells. The RIA results were in close approximation with estimation of the haemoglobin-spectrin complex obtained by carefully integrating the Coomassie blue stain profiles from 4% SDS PAGE in densitometric scans from isolated spectrin.
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Snyder LM, Fortier NL, Trainor J, Jacobs J, Leb L, Lubin B, Chiu D, Shohet S, Mohandas N. Effect of hydrogen peroxide exposure on normal human erythrocyte deformability, morphology, surface characteristics, and spectrin-hemoglobin cross-linking. J Clin Invest 1985; 76:1971-7. [PMID: 4056060 PMCID: PMC424255 DOI: 10.1172/jci112196] [Citation(s) in RCA: 177] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
To further define the conditions for forming spectrin-hemoglobin cross-linking in human erythrocyte membranes and to examine its possible effects on membrane function, we incubated normal human erythrocytes for up to 3 h in concentrations of H2O2, varying from 45 to 180 microM, in an azide phosphate buffer, pH 7.4. The chemical changes observed indicated that methemoglobin formation occurred early and at a low concentration (45 microM). Morphologic changes characterized by increased echinocyte formation occurred in a dose-dependent fashion. In addition, decreased cell deformability commensurate with increased membrane rigidity was found. Finally, an increase in cell recognition as determined by monocyte phagocytosis and adherence in vitro, as well as decreased phosphatidylcholine accessibility to bee venom phospholipase A2, was found in H2O2-treated erythrocytes compared with controls. Both of these latter changes were closely correlated with the extent of spectrin-hemoglobin cross-linking. In addition to these protein-mediated interactions, lipid peroxidation also occurred after H2O2 exposure, as shown by generation of fluorescent amino propene derivatives. The addition of the antioxidant, butylated hydroxytoluene, decreased the fluorescent derivatives, but did not prevent the effects on membrane function. This suggests that lipid peroxidation, though present, was not necessary for the membrane changes found. In contrast, spectrin-hemoglobin aggregation and the alterations in membrane function were completely prevented by prior exposure of the erythrocytes to carbon monoxide.
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Leb L, Beatson P, Fortier N, Newburger PE, Snyder LM. Modulation of mononuclear phagocyte cytotoxicity by alpha-tocopherol (vitamin E). J Leukoc Biol 1985; 37:449-59. [PMID: 2982985 DOI: 10.1002/jlb.37.4.449] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The in vitro effect of colloidal suspensions of alpha-tocopherol (alpha-T) on phorbolmyristate-acetate (PMA)-induced monocyte cytotoxicity and on antibody-dependent monocyte cytotoxicity (ADCC) was studied. We observed that 1) in the presence of alpha-T, the inhibition was twice as high in the PMA-induced assay than in ADCC; 2) monocytes preincubated with alpha-T were inhibitory in both assays but much less in ADCC, and 3) target erythrocytes preincubated with alpha-T decreased the cytotoxicity in the PMA-induced assay only. Since alpha-T preincubated monocytes showed a decreased release of H2O2 but not of O2-, we concluded that one of the mechanisms by which alpha-T decreased cytotoxicity could be decreased release of H2O2. Whereas the role of H2O2 was documented in the PMA-induced cytotoxicity, in ADCC non-oxidative injury seems more important. This is supported by 1) lesser inhibition of the assay with alpha-T preincubated monocytes; 2) lack of protection with alpha-T preincubated erythrocytes, and 3) mild inhibition with protease inhibitor.
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