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Lundehøj L, Jensen HC, Wybrandt L, Nielsen UG, Christensen ML, Quist-Jensen CA. Layered double hydroxides for phosphorus recovery from acidified and non-acidified dewatered sludge. Water Res 2019; 153:208-216. [PMID: 30716564 DOI: 10.1016/j.watres.2019.01.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/07/2019] [Accepted: 01/08/2019] [Indexed: 06/09/2023]
Abstract
Phosphate, which contains the essential element phosphorous (P), is a necessary fertilizer for agriculture, but the current phosphate deposits are running out and alternative sources are needed. Sludge obtained from wastewater treatment plants contains high concentrations of phosphorus and represents an alternative, sustainable source. In this study, sludge obtained from a wastewater treatment plant with biological and chemical phosphorus removal was acidified (pH = 3, 4, 5 and 6) to release orthophosphate followed by sequestration of the orthophosphate by a zinc aluminum layered double hydroxide (Zn2Al-LDH). Sulfuric acid (H2SO4), nitric acid (HNO3), and hydrochloric acid (HCl) was tested, which showed that only sulfate anions compete with phosphate and results in reduced phosphate recovery (25-35%). The orthophosphate concentration in the liquid phase increased from 20% (raw sludge) to 75% of the total phosphorus concentration at a pH of 3, which enhanced the phosphate uptake by the ZnAl-LDH from 1.7 ± 0.2% to 60.3 ± 0.6%. During acidification, the competing anion carbonate is degassed as CO2, which further improved the phosphate uptake. PXRD showed the intercalation of carbonate in the LDH in the raw sludge at pH = 8, whereas orthophosphate was intercalated at lower pH values. 27Al MAS NMR spectroscopy and powder X-ray diffraction (PXRD) proved preservation of the LDH at all pH values. Furthermore, about a fourth of the Al is present as an amorphous aluminum phosphate (AlPO4) upon exposure to phosphate at low pH (pH = 3 and 5) based on 27Al MAS NMR spectroscopy. At a pH of 6 about a third of the P is present as brushite (CaHPO4·2H2O).
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Affiliation(s)
- L Lundehøj
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - H C Jensen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg East, Denmark
| | - L Wybrandt
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg East, Denmark
| | - U G Nielsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - M L Christensen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg East, Denmark
| | - C A Quist-Jensen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg East, Denmark.
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Poorasgari E, Larsen P, Zheng X, Nielsen PH, Keiding K, Christensen ML. Irreversible fouling of membrane bioreactors due to formation of a non-biofilm gel layer. Water Sci Technol 2014; 69:1641-1647. [PMID: 24759523 DOI: 10.2166/wst.2014.068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Extra-cellular polymeric substances (EPS), known to contribute to fouling in membrane bio-reactors (MBRs), are generally divided into bound and free EPS. The free EPS are able to form a gel layer on the membrane active surface. The mechanisms involved in formation of such layer and its effects on performance of the MBR membranes were studied. The free EPS, extracted by centrifugation and microfiltration, contained a significant amount of humic-like substances. Under static contact to the membrane, adsorption of humic-like substances to the membrane occurred and could be explained by conventional adsorption kinetics. Due to static adsorption, surface roughness of the membrane declined significantly, indicating that adsorbed matters to the membrane filled the cavities of the membrane surface. Filtration of the free EPS caused 50% water flux decline. The fouling resistance linearly increased with the amount of the humic-like substances retained during filtration as predicted by gel growth theory. A low pressure backwash could re-establish the water flux only up to 70%.
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Affiliation(s)
- E Poorasgari
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, DK-9000, Aalborg, Denmark E-mail:
| | - P Larsen
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, DK-9000, Aalborg, Denmark E-mail:
| | - X Zheng
- Grundfos Holding, Poul Due Jensensvej 7, DK-8850 Bjerringbro, Denmark
| | - P H Nielsen
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, DK-9000, Aalborg, Denmark E-mail:
| | - K Keiding
- Grundfos Holding, Poul Due Jensensvej 7, DK-8850 Bjerringbro, Denmark
| | - M L Christensen
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, DK-9000, Aalborg, Denmark E-mail:
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Palarasah Y, Nielsen C, Sprogøe U, Christensen ML, Lillevang S, Madsen HO, Bygum A, Koch C, Skjodt K, Skjoedt MO. Novel assays to assess the functional capacity of the classical, the alternative and the lectin pathways of the complement system. Clin Exp Immunol 2011; 164:388-95. [PMID: 21401574 DOI: 10.1111/j.1365-2249.2011.04322.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Deficiencies in many of the complement proteins and their regulatory molecules have been described and a variety of diseases, such as recurrent infections, systemic lupus erythematosus (SLE) and renal diseases, may be linked to deficiency in the complement system. Screening for complement defects is therefore of great importance. In this study, we present novel improved enzyme-linked immunosorbent assays for the functional assessment of the three individual pathways of the complement system. The method is applicable at high serum concentrations and we demonstrate that it minimizes both false negative as well as false positive results. In particular, for the functional mannose-binding lectin activity it represents an improvement on the existing assays. In this respect, the present assays represent novel improved diagnostic protocols for patients with suspected immunodeficiencies related to the complement system.
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Affiliation(s)
- Y Palarasah
- Department of Cancer and Inflammation, Institute of Molecular Medicine, Faculty of Health Science, University of Southern Denmark, Odense, Denmark
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Blake MJ, Gaedigk A, Pearce RE, Bomgaars LR, Christensen ML, Stowe C, James LP, Wilson JT, Kearns GL, Leeder JS. Ontogeny of dextromethorphan O- and N-demethylation in the first year of life. Clin Pharmacol Ther 2007; 81:510-6. [PMID: 17301735 DOI: 10.1038/sj.clpt.6100101] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [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: 01/02/2023]
Abstract
The exponential increase in the number of drugs used to treat infant and childhood illnesses necessitates an understanding of the ontogeny of drug biotransformation for the development of safe and effective therapies. Healthy infants received an oral dose (0.3 mg/kg) of dextromethorphan (DM) at 0.5, 1, 2, 4, 6, and 12 months of age. DM and its major metabolites were measured in urine. CYP2D6 genotype was determined by polymerase chain reaction-restriction fragment length polymorphism. Genotyping data indicated a strong correlation between CYP2D6 genotype and DM O-demethylation (beta=-0.638; 95% CI: -0.745, -0.532; P<0.001). CYP2D6 activity was detectable and concordant with genotype by 2 weeks of age, showed no relationship with gestational age, and did not change with post natal age up to 1 year. In contrast, DM N-demethylation developed significantly more slowly over the first year of life. Genotype and the temporal acquisition of drug biotransformation are critical determinants of a drug response in infants.
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Affiliation(s)
- M J Blake
- Division of Pediatric Pharmacology and Medical Toxicology, Department of Pediatrics, Children's Mercy Hospitals and Clinics, Kansas City, Missouri, USA
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Christensen ML, Eades SK, Fuseau E, Kempsford RD, Phelps SJ, Hak LJ. Pharmacokinetics of naratriptan in adolescent subjects with a history of migraine. J Clin Pharmacol 2001; 41:170-5. [PMID: 11210397 DOI: 10.1177/00912700122009980] [Citation(s) in RCA: 12] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Naratriptan is a novel 5-HT1 agonist developed to treat acute migraine. The study objective was to characterize the pharmacokinetics of oral naratriptan in adolescent migraine patients outside a migraine attack. Subjects received a single 2.5 mg naratriptan tablet. Serial serum samples for naratriptan concentrations were collected over 24 hours. Blood pressure, pulse rate, and 12-lead ECG were recorded at baseline and at regular intervals after dosing. Seven patients--3 males and 4 females, 12 to 16 years of age--received drug and completed the study. The geometric mean and 95% confidence interval maximum concentration (Cmax) was 8.0 ng/mL (5.9-10.7), elimination half-life (t1/2) was 4.9 hours (4.5-5.4), area under the concentration-time curve (AUC) was 74.6 ng.h/mL (56.6-98.2), and apparent total clearance (Cl/F) was 558.8 mL/min (424.3-735.9). The median time to maximal concentration (tmax) was 4 hours, with a range of 1.5 to 4. Blood pressure, pulse rate, and ECG parameters did not change significantly from baseline. No serious adverse events or subject withdrawal after drug administration occurred. Oral naratriptan pharmacokinetic parameters in adolescents were similar to values reported in adults. Naratriptan doses for adolescents older than 12 years of age would be expected to be similar to adult doses.
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Affiliation(s)
- M L Christensen
- Department of Clinical Pharmacy, Pediatric Pharmacology Research Unit, Center for Pediatric Pharmacokinetics and Therapeutics, University of Tennessee, Memphis 38163, USA
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Edick CM, Parnell D, Christensen ML, Hak LJ. Falsely elevated systolic blood pressure with patient-operated blood pressure measuring devices. J Am Pharm Assoc (Wash) 2000; 40:670-2. [PMID: 11029849 DOI: 10.1016/s1086-5802(16)31108-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Affiliation(s)
- C M Edick
- Department of Clinical Pharmacy, University of Tennessee, Memphis 38163, USA
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Abstract
Tacrolimus is an immunosuppressant used to prevent rejection of transplanted organs. It is metabolized in both the gut and the liver by the cytochrome P450 (CYP) 3A4 enzyme system and is a substrate for the P-glycoprotein (P-gp) drug efflux pump. As CYP3A4 enzymes and P-gp are present at differing concentrations throughout the gastrointestinal tract, the bioavailability of tacrolimus may be influenced by changes in gastrointestinal transit time in addition to changes in hepatic metabolism. We report the case of a pediatric renal transplant patient who experienced a three-fold increase in serum tacrolimus concentrations during an episode of gastroenteritis with chronic diarrhea.
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Affiliation(s)
- S K Eades
- Department of Pediatrics, Tulane University School of Medicine and Tulane University Medical Center, New Orleans, Louisiana 70112, USA.
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Mouser JF, Hak EB, Helms RA, Christensen ML, Storm MC. Chromium and zinc concentrations in pediatric patients receiving long-term parenteral nutrition. Am J Health Syst Pharm 1999; 56:1950-6. [PMID: 10554913 DOI: 10.1093/ajhp/56.19.1950] [Citation(s) in RCA: 12] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Serum, urine, and parenteral nutrition (PN) chromium and zinc concentrations in pediatric patients receiving long-term PN were studied. Serum, urine, and PN chromium and zinc concentrations were measured at baseline and four to six months later in four infants (less than 1 year old) and seven children (1-12 years old) receiving long-term PN. In the children, serum, urine, and PN solution zinc concentrations were measured monthly after the amino acid product was changed from a standard to a pediatric product with monthly dosages of 0, 20, 30, and 40 mg of cysteine hydrochloride per gram of amino acids. The mean +/- S.D. baseline serum chromium concentration was 4.9+/-1.9 microg/L (normal value, <0.3 microg/L); the urine chromium concentration ranged from 3.4 to 32.2 microg/L. The mean +/- S.D. prescribed chromium dosage was 0.18+/-0.05 microg/kg/day, and the dosage delivered in PN solutions was 0.41+/-0.23 microg/ kg/day. At baseline, the mean +/- S.D. serum zinc concentration was 1383+/-472 microg/L (normal range, 430 to 940 microg/L), and the prescribed and delivered zinc dosages were 177+/-10 and 238+/-145 microg/kg/ day, respectively. With 20, 30, and 40 mg of cysteine per gram of amino acids, the mean +/- S.D. serum zinc concentration was 1728+/-782, 1664+/-349, and 1685+/-268 microg/L, respectively, and the actual zinc dosages delivered were 209+/-10, 270+/-148, and 322+/-194 microg/kg/day, respectively. Serum and urine chromium concentrations were abnormally high in infants and children receiving PN solutions supplemented with normal doses of these trace elements; an escalating dosage of cysteine in the children tended to increase serum and urine zinc concentrations.
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Affiliation(s)
- J F Mouser
- Department of Pharmacy Practice, University of Connecticut, Storrs, USA
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Christensen ML, Helms RA, Chesney RW. Is pediatric labeling really necessary? Pediatrics 1999; 104:593-7. [PMID: 10469796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
Affiliation(s)
- M L Christensen
- Departments of Pediatrics, Pediatric Pharmacology Research Unit, Center for Pediatric Pharmacokinetics and Therapeutics, The University of Tennessee, LeBonheur Children's Medical Center, Memphis, Tennessee, USA
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Helms RA, Storm MC, Christensen ML, Hak EB, Chesney RW. Cysteine supplementation results in normalization of plasma taurine concentrations in children receiving home parenteral nutrition. J Pediatr 1999; 134:358-61. [PMID: 10064677 DOI: 10.1016/s0022-3476(99)70465-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We evaluated plasma sulfur amino acid concentrations in children with short gut syndrome receiving home parenteral nutrition (n = 6). Cysteine HCl addition to solutions formulated with a pediatric amino acid product will increase plasma taurine concentrations to within the normal reference range.
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Affiliation(s)
- R A Helms
- Departments of Clinical Pharmacy and Pediatrics, Center for Pediatric Pharmacokinetics and Therapeutics, The University of Tennessee, Memphis 38163-2111, USA
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Abstract
The loop diuretics furosemide and bumetanide are frequently employed in the pediatric population for the management of fluid overload in both acute and chronic disease states. They act mainly by inhibiting sodium reabsorption in the nephron at the thick ascending limb of Henle's loop. Important pharmacokinetic differences between adults and infants include a reduced clearance and prolonged half-life, that may cause accumulation of these agents to potentially toxic levels if dosing intervals are not adjusted. Unfortunately, little is known about the time required for maturation of loop diuretic elimination in older infants, children, and adolescents. Similar to adults, limited pharmacodynamic evidence in neonates suggests that a maximally efficient diuretic dose exists. Increasing the diuretic dose beyond this maximum does not offer further benefit, but may increase the risk of toxicity. Common problems encountered in the pediatric patient as well as in adults are loop diuretic tolerance and resistance. Loop diuretic dosing strategies aimed at overcoming these phenomena include administration by continuous infusion, coadministration with albumin, and coadministration with metolazone or thiazides. This article reviews the pharmacology, pharmacokinetics, and pharmacodynamics of furosemide and bumetanide in pediatric patients. A better understanding of the clinical pharmacology of the loop diuretics should aid clinicians in the development of dosing regimens aimed at producing adequate diuresis without promoting excessive diuretic tolerance.
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Affiliation(s)
- S K Eades
- Department of Clinical Pharmacy, Crippled Children's Foundation Research Center, University of Tennessee, Memphis, 38163, USA
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Pachman LM, Hayford JR, Hochberg MC, Pallansch MA, Chung A, Daugherty CD, Athreya BH, Bowyer SL, Fink CW, Gewanter HL, Jerath R, Lang BA, Szer IS, Sinacore J, Christensen ML, Dyer AR. New-onset juvenile dermatomyositis: comparisons with a healthy cohort and children with juvenile rheumatoid arthritis. Arthritis Rheum 1997; 40:1526-33. [PMID: 9259435 DOI: 10.1002/art.1780400822] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To determine, in a case-control study, if patients with new-onset juvenile dermatomyositis (juvenile DM) have increased symptoms prior to onset, exposure to certain environmental conditions, frequency of familial autoimmune diseases, or antibody titers, compared with 2 control groups. METHODS A structured interview with the families of 80 children with juvenile DM, 40 children with juvenile rheumatoid arthritis (JRA), or 23 healthy children, from the same geographic area as the children with juvenile DM, was conducted. All children's sera were tested for antibody to Toxoplasma gondii, herpes simplex virus (HSV), or coxsackievirus B (CVB). RESULTS A high proportion of children with juvenile DM had constitutional symptoms 3 months before the disease-onset date (P = 0.013 versus control children). Children with JRA had more relatives with rheumatoid arthritis (P = 0.0001) and pernicious anemia (P = 0.003) than did children with juvenile DM or healthy children. Among children < or =7 years of age, elevated enteroviral titers were more frequent in those with juvenile DM (81%) and in healthy controls (90%) than in those with JRA (64%), suggesting a common environmental exposure. Titers to T gondii, HSV, or CVB 1-6 were normal. CONCLUSION Frequencies of familial autoimmune disease, exposure to environmental factors, or elevated antibody titers to T gondii, HSV, or CVB are not increased in juvenile DM. Children with juvenile DM do have symptoms of illness 3 months before the disease-onset date, and young patients have elevated enteroviral titers, as do young geographic controls.
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Affiliation(s)
- L M Pachman
- Northwestern University Medical School, Chicago, Illinois 60614, USA
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Abstract
PURPOSE The purpose of this study was to determine the dose-concentration relationship and clinical effect of transdermal fentanyl (TF) in patients with sickle cell pain crisis (SCPC). PATIENTS AND METHODS Ten patients aged 9-16 years were studied. Patients initially received a TF dose of 25 (n = 7) or 50 (n = 3) micrograms/h if morphine use was > 2.5 mg/h. Supplemental morphine usage via patient-controlled analgesia (PCA), sedation status, pain status, respiratory rate, pulse rate, oxygen saturation, and blood pressure were monitored. RESULTS The average TF dose was 0.77 +/- 0.37 micrograms/kg/h on day 1 and 1.17 +/- 0.46 micrograms/kg/h on day 2. Fentanyl concentrations measured at 24 and 48 h were 0.60 +/- 0.31 and 1.18 +/- 0.44 ng/ml, respectively. A significant relationship existed between TF dose and fentanyl concentration (r2 = 0.56, p < 0.01). There was no difference in any of the clinical monitoring parameters between day 1 and day 2. However, 7 of 10 patients reported subjective improvement in pain control over that achieved with PCA alone. No adverse effects were noted. CONCLUSIONS Improved understanding of the dose-effect relationship for TF in children and adolescents is necessary before adequate pain control can be achieved with this delivery system.
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Affiliation(s)
- M L Christensen
- Department of Clinical Pharmacy, University of Tennessee, Memphis 38163, USA
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Christensen ML. Effect of abrupt discontinuation of high glucose infusion rates during parenteral nutrition. JPEN J Parenter Enteral Nutr 1996; 20:309-10. [PMID: 8865116 DOI: 10.1177/014860719602000415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Crom WR, de Graaf SS, Synold T, Uges DR, Bloemhof H, Rivera G, Christensen ML, Mahmoud H, Evans WE. Pharmacokinetics of vincristine in children and adolescents with acute lymphocytic leukemia. J Pediatr 1994; 125:642-9. [PMID: 7931891 DOI: 10.1016/s0022-3476(94)70027-3] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We studied the pharmacokinetics of vincristine in children with acute lymphocytic leukemia by means of a specific high-performance liquid chromatographic assay with ultraviolet and electrochemical detection and a limited sampling strategy. Our objectives were to characterize the disposition of vincristine in pediatric patients, to determine clinical, demographic, or biochemical variables related to variability in vincristine pharmacokinetic parameters, and to assess the relationship between pharmacokinetic parameters and vincristine neurotoxicity. Plasma samples were collected at 5 and 30 minutes, and 1, 3, and 24 hours after a rapid intravenous injection during 3 minutes. Vincristine-induced neurotoxicity was retrospectively evaluated by chart review. Pharmacokinetic studies were completed for 64 doses in 54 children between 2 months and 18 years of age (median, 4.3 years), including 2-month-old monozygous twin girls. Vincristine clearance, estimated by Bayesian methods, was highly variable, with a mean (SD) clearance of 19.9 (14.9) ml/min per kilogram or 482 (342) ml/min per square meter. Mean clearance for all subjects was faster than in published studies of adults, which may be related in part to the greater specificity of the assay used in our study, as well as to age-related differences in drug disposition. Vincristine-associated neurotoxicity was frequent but mild and was not predicted by vincristine systemic exposure; however, neurotoxicity may have been underestimated. Clearance in one patient who received concomitant treatment with pentobarbital exceeded the 75th percentile for all patients, and four of five patients receiving concomitant histamine2 antagonists had clearances below the 25th percentile for all subjects, suggesting that drugs that induce or inhibit hepatic cytochrome P-450 enzymes may affect vincristine disposition. Further studies are needed to identify the factors responsible for interpatient variability in vincristine disposition and to develop improved dosing guidelines.
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Affiliation(s)
- W R Crom
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee
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Abstract
BACKGROUND Recent meta-analyses of published controlled studies concluded that adult patients with cancer randomly assigned to receive parenteral nutrition had higher rates of infectious complications than control subjects. METHODS The infection risk associated with parenteral nutrition was assessed in 310 pediatric patients with cancer. These patients had central venous access devices (CVAD), Hickman/Broviac (H/B) catheters, or implantable subcutaneous ports in place for the delivery of chemotherapy and supportive care. RESULTS The median duration of CVAD placement was 363 days; a total of 450 patient years (i.e., the sum of the total years of catheters experienced from all patients studied) were examined. Overall, the infection rate was 0.06 infections/100 days. During the period of parenteral nutrition administration, the rate increased to 0.5 infections/100 days. Among patients who received parenteral nutrition, there were no significant differences in any clinical parameter between the patients who developed an infection and those who did not. When evaluating the entire study population, infection was more likely to occur in patients who had acute nonlymphocytic leukemia (P < 0.01) or H/B catheters (P < 0.01), or who received parenteral nutrition (P < 0.02); there was no relationship between infection and catheter duration, days hospitalized, or days neutropenic (absolute neutrophil count < 0.5 x 10(9)/l). Only CVAD type and parenteral nutrition retained significance in a multivariate Cox proportional hazards model. After adjustment for diagnosis and CVAD type, the risk of infection was 2.4-fold greater in patients given parenteral nutrition (95% confidence interval 1.5 to 3.9; P < 0.001). CONCLUSION These data confirm that administration of parenteral nutrition is associated with an increased risk of infection in children who have CVAD in place for cancer therapy.
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Affiliation(s)
- M L Christensen
- Pharmaceutical Division, St. Jude Children's Research Hospital, Memphis, Tennessee
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Christensen ML, Helms RA, Veal DF, Boehm KA, Storm MC. Clearance of N-acetyl-L-tyrosine in infants receiving a pediatric amino acid solution. Clin Pharm 1993; 12:606-9. [PMID: 8222526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- M L Christensen
- Department of Clinical Pharmacy, University of Tennessee, Memphis 38163
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19
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Christensen ML, Burgess J, Helms RA, Mirro J, Kalwinsky DK, Storm MC. Plasma amino acids in patients with acute nonlymphocytic leukemia receiving parenteral nutrition. Ann Pharmacother 1993; 27:146-50. [PMID: 8439686 DOI: 10.1177/106002809302700201] [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: 01/30/2023] Open
Abstract
OBJECTIVE To assess the effect of parenteral amino acid solutions on plasma amino acid concentrations in patients with acute nonlymphocytic leukemia (ANLL) receiving parenteral nutrition (PN). DESIGN Ten patients were studied at diagnosis, on the morning PN was started, and three times during PN therapy coinciding with the sequential administration of three different amino acid solutions (Aminosyn, FreAmine HBC, and TrophAmine). The order of amino acid solution administration in each patient was by a randomized, block design. RESULTS The patients were undergoing identical intensive induction therapy. There was no significant difference in the number of days they received PN or the amount of protein or calories received during the three PN study periods. At diagnosis, phenylalanine and glutamic acid concentrations were elevated compared with previously published normal values and remained elevated at all observation times. During PN, asparagine, aspartic acid, and tyrosine concentrations were significantly lower with all three amino acid solutions compared with their concentrations at diagnosis. Glycine and threonine concentrations were also significantly lower with FreAmine HBC and TrophAmine administration and cysteine concentrations were significantly lower with FreAmine HBC administration than at the time of diagnosis. Aminosyn was associated with plasma amino acid concentrations most similar to those measured at diagnosis. CONCLUSIONS These results indicate that most amino acid concentrations fall within the normal range at diagnosis in the ANLL patients studied. Plasma concentrations for certain amino acids can be influenced by the amino acid solution used in PN. Further understanding of the derangements in amino acid metabolism and the influence of parenterally administered amino acid solutions on plasma amino acid concentrations may lead to improvements in the nutritional support of cancer patients.
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Affiliation(s)
- M L Christensen
- Pharmaceutical Division, St. Jude Children's Research Hospital, Memphis, TN
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Helms RA, Mowatt-Larssen CA, Boehm KA, Christensen ML, Hughes MA, Fernandes ET, Storm MC. Urinary nitrogen constituents in the postsurgical preterm neonate receiving parenteral nutrition. JPEN J Parenter Enteral Nutr 1993; 17:68-72. [PMID: 8437328 DOI: 10.1177/014860719301700168] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Minimal information is available defining urinary nitrogen constituents in preterm neonates receiving parenteral nutrition (PN). The study objective was to evaluate 24-hour urine collections for total urinary nitrogen (TUN), urinary urea nitrogen (UUN), and the nitrogen content in creatinine, ammonia, free amino acids, protein, hippuric acid, and uric acid at baseline (days 1 to 2 of PN and days 1 to 3 after surgery) and 7 days later in eight preterm, postsurgical neonates. Calculation of undetermined nitrogen was also completed. Comparisons with historic, normal data were made for each urinary nitrogen constituent. At baseline, PN provided 59 +/- 10 nonprotein kcal/kg.day-1 and 430 +/- 54 mg/kg.day-1. At day 7, PN provided 106 +/- 23 nonprotein kcal/kg.day-1 and 432 +/- 30 mg/kg.day-1. TUN, UUN, and protein nitrogen decreased significantly from baseline at day 7 (p < .05). The percentages of TUN as amino acids, creatinine, and uric acid nitrogen were calculated. Percent amino acid nitrogen (6.0 +/- 2.3% vs 8.4 +/- 1.5%, p < .05), percent creatinine nitrogen (1.6 +/- 0.5% vs 2.9 +/- 0.8%, p < .001) and percent uric acid nitrogen (1.7 +/- 0.9% vs 3.6 +/- 2.1%, p < .05) increased significantly at day 7. The observed urinary free amino acid nitrogen fraction represented a higher percentage of TUN both at baseline and at day 7 when compared with term neonatal reference data, whereas creatinine nitrogen, uric acid nitrogen, and protein nitrogen represented a lower percentage of TUN. However, amino acid and creatinine nitrogen as a percentage of TUN were similar to levels in milk formula-fed preterm infants.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R A Helms
- Department of Clinical Pharmacy, University of Tennessee, Memphis 38163
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21
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Clifton GL, Christensen ML. Use of moderate hypothermia during elective craniotomy. Tex Med 1992; 88:66-9. [PMID: 1287870] [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: 12/26/2022]
Abstract
Use of moderate hypothermia as an adjunct to elective craniotomy is described in 21 patients. Systemic hypothermia to 32 degrees C was induced by cooling blankets at a mean cooling rate of 1.6 degrees C/min. Patients were rewarmed at the same rate prior to closure of wounds. There were no hypothermia-related complications and the method increased brain relaxation. The rationale for use of this therapy in elective craniotomy and severe head injury is reviewed.
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Affiliation(s)
- G L Clifton
- Department of Surgery, University of Texas Health Science Center, Houston 77030
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22
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Abstract
PURPOSE A possible pharmacokinetic interaction between teniposide and anticonvulsant medications was evaluated in pediatric patients. PATIENTS AND METHODS The systemic clearance of teniposide was determined in six pediatric patients with acute lymphocytic leukemia receiving concomitant therapy with anticonvulsants. Clearance was then compared with a control group of patients treated with the same protocol therapy and matched for age at diagnosis, sex, and race but not receiving anticonvulsants or other agents known to induce hepatic metabolism or alter protein binding of drugs. Eight blood samples were obtained during and after 4-hour infusions of teniposide, and plasma concentrations were measured by a specific high-performance liquid chromatography (HPLC) assay. A two-compartment model was fitted to each subject's data. RESULTS The mean systemic clearance (range) for the six anticonvulsant-treated patients studied during 22 courses of therapy was 32 mL/min/m2 (range, 21 to 54 mL/min/m2), significantly higher (P less than .001) than the mean value of 13 mL/min/m2 (range, 7 to 17 mL/min/m2) for the control patients studied during 26 courses of therapy. Clearance estimates for control patients were similar to previously published values for pediatric patients. CONCLUSION These data indicate that the systemic clearance of teniposide is consistently increased two- to three-fold by concomitant phenobarbital or phenytoin therapy. The consequent substantial reduction in systemic exposure may reduce teniposide's efficacy.
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Affiliation(s)
- D K Baker
- Pharmacokinetics and Pharmacodynamics Section, St Jude Children's Research Hospital, Memphis, TN 38105
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23
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Crom WR, Relling MV, Christensen ML, Rivera GK, Evans WE. Age-related differences in hepatic drug clearance in children: studies with lorazepam and antipyrine. Clin Pharmacol Ther 1991; 50:132-40. [PMID: 1868674 DOI: 10.1038/clpt.1991.117] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [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: 12/29/2022]
Abstract
The disposition of intravenous antipyrine and lorazepam, administered as model substrates for hepatic oxidative metabolism and conjugation, was evaluated in 50 children (mean age, 7.8 years; range, 2.3 to 17.8 years) with acute lymphocytic leukemia in complete remission and compared with a group of ten healthy adults. Antipyrine clearance normalized to body weight was significantly greater in children than in adults (0.91 versus 0.59 ml/min/kg; p = 0.012), but was not different when normalized to body surface area. In contrast, lorazepam total clearance (CL) and unbound clearance (CLu) normalized to body weight were not significantly different between children and adults but were smaller in children when normalized to body surface area (CL = 31.9 versus 40.6 ml/min/m2, p = 0.036; CLu = 352 versus 485 ml/min/m2, p = 0.010). The mean lorazepam fraction unbound in children was 0.087, which was not different from adult volunteers (0.084). This study has identified significant differences between children and adults in the disposition of these two compounds, with higher milliliter per minute per kilogram clearance for antipyrine but not lorazepam.
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Affiliation(s)
- W R Crom
- Pharmacokinetics and Pharmacodynamics Section, St. Jude Children's Research Hospital, Memphis, TN 38105
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24
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Phelps SJ, Brown RO, Helms RA, Christensen ML, Kudsk K, Cochran EB. Toxicities of parenteral nutrition in the critically ill patient. Crit Care Clin 1991; 7:725-53. [PMID: 1907525] [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: 12/29/2022]
Abstract
Critically ill patients have unique nutritional substrate requirements. Although important advances have been made in understanding these requirements in the face of pathophysiologic and biochemical alterations induced by stress or trauma, nutrition-associated toxicities still occur. The importance of these toxicities to the critically ill patients cannot be over-stated. Many of these toxicities can be avoided by conservative use of selected nutrition substrates in specific subsets of the critically ill population. Practitioners must continue to anticipate and recognize parenteral nutrition-associated toxicities, however, as well as delineate any toxicity from the progression or exacerbation of disease.
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Affiliation(s)
- S J Phelps
- Department of Clinical Pharmacy, University of Tennessee, Memphis
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25
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Howard C, Friedman DL, Leete JK, Christensen ML. Correlation of the percent of positive Chlamydia trachomatis direct fluorescent antibody detection tests with the adequacy of specimen collection. Diagn Microbiol Infect Dis 1991; 14:233-7. [PMID: 1889175 DOI: 10.1016/0732-8893(91)90037-g] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [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: 12/29/2022]
Abstract
Chlamydia trachomatis is an obligate, intracellular parasite infecting the columnar and transitional cells lining the endocervix, uterus, fallopian tubes, rectum, urethra, and epididymis. We determined if the percent of specimens positive for C. trachomatis in the Microtrak Direct Specimen Test depended on the quality of specimens obtained. Female genital slides (649) were evaluated by the direct fluorescent antibody (DFA) test for the presence and numbers of (a) C. trachomatis elementary bodies and (b) columnar, transitional and squamous epithelial cells, and polymorphonuclear neutrophils (PMNs). Only 138 (21.3%) of the 649 slides were considered to be adequately taken, that is, containing columnar/transitional cells either alone or in conjunction with squamous cells and/or PMNs. Of the 138 adequate slides, 10 (7.2%) were C. trachomatis positive. However, 511 (78.7%) of the 649 slides were judged inadequate; 395 contained only squamous cells and/or PMNs, 19 were too thick to determine cell types, 46 contained only cell debris, and 51 contained neither cells nor debris. Only four (0.78%) of 511 were C. trachomatis positive. Thus adequate specimens containing columnar/transitional cells for C. trachomatis detection had a tenfold increase in the percent of positive results compared to inadequately collected specimens. By using the DFA test, one has the advantage of determining the adequacy of the specimens obtained as well as the presence of chlamydiae.
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Affiliation(s)
- C Howard
- Department of Pathology, Children's Memorial Hospital, Chicago, IL 60614
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26
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Helms RA, Mauer EC, Hay WW, Christensen ML, Storm MC. Effect of intravenous L-carnitine on growth parameters and fat metabolism during parenteral nutrition in neonates. JPEN J Parenter Enteral Nutr 1990; 14:448-53. [PMID: 2122016 DOI: 10.1177/0148607190014005448] [Citation(s) in RCA: 30] [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] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To determine whether intravenous carnitine can improve nutritional indices, neonates requiring parenteral nutrition were randomized into carnitine treatment (n = 23) and control (n = 20) groups. Observed plasma lipid indices, carnitine and nitrogen balances, and plasma carnitine concentrations were not different in the prestudy period. Under standardized, steady-state conditions, 0.5 g/kg Intralipid was administered intravenously over 2 hr prior to carnitine administration, after infants received 7 days of 50 mumol/kg/day, and after a second 7 days of 100 mumol/kg/day of continuous intravenous L-carnitine as part of parenteral nutrition. Triglyceride (TGY), free fatty acid (FFA), acetoacetate (AA), beta-hydroxybutyrate (BOB), and plasma carnitine concentrations were measured prior to and at 2, 4, and 6 hr after the initiation of the lipid bolus. Twenty-four-hour urine collections for nitrogen and carnitine balance were obtained on days 7 and 14. Neonates receiving carnitine had significantly greater concentrations of plasma carnitine on days 7 and 14 (p less than 0.001). Greater nitrogen (p less than 0.05) and carnitine (p less than 0.001) balances and weight gain (week 2, p less than 0.05) were found in the carnitine-supplemented group when compared with controls. On day 14, (BOB + AA)/FFA ratios were significantly higher (p less than 0.05), and peak TGY concentrations and 6-hr FFA concentrations were significantly lower (p less than 0.05) in the treatment group. Carnitine supplementation was associated with modest increases in growth and nitrogen accretion possibly by enhancing the neonate's ability to utilize exogenous fat for energy.
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Affiliation(s)
- R A Helms
- Center for Pediatric Pharmacokinetics and Therapeutics, University of Tennessee, Memphis
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27
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Tucker JD, Wyrobek AJ, Ashworth LK, Christensen ML, Burton GV, Carrano AV, Everson RB. Induction, accumulation, and persistence of sister chromatid exchanges in women with breast cancer receiving cyclophosphamide, adriamycin, and 5-fluorouracil chemotherapy. Cancer Res 1990; 50:4951-6. [PMID: 2379160] [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]
Abstract
The induction, accumulation, and persistence of sister chromatid exchanges (SCEs) and high SCE frequency cells (HFCs) was measured in peripheral blood lymphocytes of women with breast cancer before chemotherapy and on multiple occasions during and after therapy. Chemotherapy consisted of i.v. infusion of cyclophosphamide, Adriamycin, and 5-fluorouracil, administered on day 1 of each of approximately six 21-day cycles. This treatment resulted in a highly significant induction of SCEs (1.8-fold, P less than 0.0001) and HFCs (5-fold, P less than 0.0001) measured in samples obtained 1 week after the first therapy. Accumulation of lesions leading to SCEs was measured by comparing samples surrounding the first and last rounds of therapy and was significant for both SCEs and HFCs in most comparisons. Persistence of lesions leading to SCEs was evaluated at multiple times until 9 months after completion of therapy, and both SCEs and HFCs remained significantly elevated throughout this time. Differences between donors were observed throughout the study, although they were not always consistent with time. Our results also indicate that the SCE frequency declines rapidly within a few weeks after treatment but that residual damage remains up to 9 months after the end of chemotherapy.
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Affiliation(s)
- J D Tucker
- Lawrence Livermore National Laboratory, Biomedical Sciences Division, University of California, Livermore 94551
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28
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Abstract
The traditional analysis and assembly of metaphase chromosomes into a karyogram is a slow and tedious process requiring intermediate photographic steps and manual manipulation of the chromosome images. Much of this task is highly repetitive and readily lends itself to partial automation. Semi-automated karyotyping systems now are being used increasingly in both clinical and research cytogenetic laboratories. Digital image processing techniques are used to capture, manipulate, and make an initial classification of chromosome images. The Athena system uses commercially available components based on a Macintosh II personal computer. Digital image processing procedures automatically isolate chromosome images from the metaphase and arrange them into a karyogram, using information about relative chromosome length, centromeric index, and banding pattern. The operator uses the intuitive graphics interface of the Macintosh computer to monitor each phase of the analysis, to resolve any problems in isolating chromosome images, and to rearrange the individual chromosome images while assembling the final karyogram. Athena is designed as a semi-automated karyotyping system that is easy to learn and has sufficient power and versatility for routine use in the analysis of human metaphase chromosomes.
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Affiliation(s)
- B H Mayall
- Biomedical Sciences Division L-452, Lawrence Livermore National Laboratory, California 94551
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29
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Abstract
The alterations in aminoglycoside disposition in patients previously treated with cisplatin were determined by reviewing the medical records of 37 cancer patients. The patients received 44 courses of an aminoglycoside antibiotic (gentamicin, n = 27; amikacin, n = 14; and tobramycin, n = 3). The mean (SD) half-life of 171 (120) min was greater than our previously published mean aminoglycoside half-life in children with cancer who were not receiving cisplatin. Twenty-five of 44 courses were completed without an aminoglycoside dosage reduction and only 5 courses were discontinued because of delayed aminoglycoside elimination. There was no significant difference in the duration of aminoglycoside therapy between the group that had a dosage reduction and the group that did not [6.6 (2.3) versus 5.8 (2.9) days, p = 0.42, respectively]. Multiple linear regression analysis of patient variables identified serum creatinine and cumulative cisplatin dose as the best predictors of aminoglycoside half-life (r2 = 46.0%, p less than 0.001). The only predictor of aminoglycoside clearance was serum creatinine (r2 = 35.2%, p less than 0.001). Patients previously treated with cisplatin are at greater risk for delayed aminoglycoside elimination. Prior administration of cisplatin is not an absolute contraindication to the use of aminoglycoside antibiotics. When clinically indicated, patients who have previously received cisplatin and have apparently normal renal function should be treated cautiously with standard doses of aminoglycoside antibiotics, and pharmacokinetic monitoring should be routinely performed.
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Affiliation(s)
- M L Christensen
- Pharmaceutical Division, St. Jude Children's Research Hospital, Memphis, Tennessee
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30
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Abstract
The relationships among plasma total carnitine concentration, postnatal age, and fatty acid metabolism were evaluated in 57 infants receiving parenteral nutrition. Concentrations of plasma carnitine, triglycerides, free fatty acids, acetoacetate, and beta-hydroxybutyrate were determined before and at 2 and 4 hours from the beginning of a standardized 2-hour lipid infusion. Plasma carnitine concentrations declined with increasing postnatal age. There were no significant differences in gestational age or triglyceride concentrations between infants less than or equal to 4 weeks of age and those greater than 4 weeks of age, whereas free fatty acid concentrations were lower and acetoacetate and beta-hydroxybutyrate concentrations were higher in the younger infants. Infants less than or equal to 4 weeks of age were further grouped according to plasma carnitine concentration greater than 13 nmol/ml (group 1) and less than or equal to 13 nmol/ml (group 2) and were then compared with infants greater than 4 weeks of age (group 3). There were no significant differences in triglyceride concentrations among the three groups; free fatty acids, acetoacetate, and beta-hydroxybutyrate concentrations for group 2 patients were similar to those of group 1 patients or fell between values for group 1 and group 3 patients. These results demonstrate decreasing plasma carnitine concentrations and possibly for more than 4 weeks.
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Affiliation(s)
- M L Christensen
- Pharmaceutical Division, St. Jude Children's Research Hospital, Memphis, Tennessee
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31
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Tucker JD, Taylor RT, Christensen ML, Strout CL, Hanna ML, Carrano AV. Cytogenetic response to 1,2-dicarbonyls and hydrogen peroxide in Chinese hamster ovary AUXB1 cells and human peripheral lymphocytes. Mutat Res 1989; 224:269-79. [PMID: 2507914 DOI: 10.1016/0165-1218(89)90166-3] [Citation(s) in RCA: 19] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mutagenic 1,2-dicarbonyls have been reported to occur in coffee and other beverages and in various foods. We have measured the induction of sister-chromatid exchanges (SCEs) and endoreduplicated cells (ERCs) to determine the genotoxicity of various 1,2-dicarbonyl compounds in Chinese hamster ovary (CHO) AUXB1 cells and human peripheral lymphocytes. The 1,2-dicarbonyls glyoxal, methylglyoxal and kethoxal each induced highly significant increases in both SCEs and ERCs in AUXB1 cells. Glyoxal and kethoxal induced SCEs but not ERCs in human peripheral lymphocytes. In addition, hydrogen peroxide induced highly significant levels of SCEs and ERCs in AUXB1 cells. Bisulfite, which reacts with carbonyl groups to form addition products, significantly reduced the frequency of SCEs and the proportion of ERCs when glyoxal, methylglyoxal, kethoxal and diacetyl were administered to AUXB1 cells. In addition, bisulfite blocked the formation of ERCs, but not SCEs, induced by hydrogen peroxide. These in vitro results suggest that 1,2-dicarbonyls may play an important role in the genotoxicity of some foods and beverages.
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Affiliation(s)
- J D Tucker
- Lawrence Livermore National Laboratory, University of California 94550
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32
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Abstract
Using a variety of in vivo cytogenetic endpoints, we have investigated the effects of several compounds formed during the cooking of meat. C57Bl/6 mice were used to test for an increase in the frequency of sister-chromatid exchanges (SCEs), chromosomal aberrations, and micronucleated erythrocytes by 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx). 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). MeIQx and DiMeIQx did not induce SCEs in mouse bone marrow cells. PhIP induced sister-chromatid exchanges, but not chromosomal aberrations in bone marrow. In peripheral blood lymphocytes, PhIP did induce aberrations at 100 mg/kg, the highest dose tested. PhIP induced a low but significantly increased frequency of micronuclei in normochromatic but not polychromatic erythrocytes in bone marrow and peripheral blood. However, dose responses were not observed. With the exception of the SCEs induced by PhIP, these results contrast with observations made in vitro, where these compounds were found to have significant genotoxicity in mammalian cells and a very high mutation frequency in prokaryotic systems.
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Affiliation(s)
- J D Tucker
- Biomedical Sciences Division, Lawrence Livermore National Laboratory, CA 94550
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33
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Tucker JD, Taylor RT, Christensen ML, Strout CL, Hanna ML. Cytogenetic response to coffee in Chinese hamster ovary AUXB1 cells and human peripheral lymphocytes. Mutagenesis 1989; 4:343-8. [PMID: 2687627 DOI: 10.1093/mutage/4.5.343] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [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: 01/02/2023] Open
Abstract
We have investigated the genotoxic effects of three different brands and three types of coffee (freshly brewed regular, instant regular and freshly brewed decaffeinated) in two mammalian systems: the Chinese hamster ovary (CHO) AUXB1 cell line and human peripheral lymphocytes. Sister-chromatid exchanges (SCEs) and endoreduplicated cells (ERCs) were used as the endpoints. Coffee was prepared according to the manufacturer's suggestions, and after cooling, administered to cultured cells at dilutions ranging up to 11% that of full-strength coffee. Each brand and type of coffee induced significant levels of SCEs and ERCs in AUXB1 cells. SCEs, but not ERCs, were induced in human peripheral lymphocytes. Bisulfite, which complexes with carbonyls and reduces their genotoxicity, significantly diminished the number of SCEs and ERCs found after administration of coffee. Catalase and peroxidase, enzymes that destroy hydrogen peroxide activity, had no significant effect upon the SCE and ERC frequencies in AUXB1 cultures treated with freshly brewed regular coffee. These experiments indicate that different brands and types of coffee have sufficient genotoxic activity to increase SCEs and ERCs at levels only a fraction of those normally consumed. 1,2-Dicarbonyls alone and peroxides alone do not appear to be responsible for the majority of SCEs and ERCs that were observed to be induced by dilute coffee.
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Affiliation(s)
- J D Tucker
- Lawrence Livermore National Laboratory, Biomedical Sciences Division, University of California, Livermore 94550
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34
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Evans WE, Relling MV, de Graaf S, Rodman JH, Pieper JA, Christensen ML, Crom WR. Hepatic drug clearance in children: studies with indocyanine green as a model substrate. J Pharm Sci 1989; 78:452-6. [PMID: 2760818 DOI: 10.1002/jps.2600780605] [Citation(s) in RCA: 24] [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: 01/02/2023]
Abstract
For several drugs metabolized by the liver, higher dosages (mg/kg body weight) are required in children to attain serum concentrations comparable to those in adults. Indocyanine green (ICG), a commonly used model substrate for hepatic elimination of high intrinsic clearance drugs, has been extensively evaluated in adults but not in children. We evaluated the disposition of ICG in 115 children with leukemia and nine healthy adult volunteers. The mean (SD) ICG plasma clearance (CLp) for all 115 children (age 0.9-17.8 years) was significantly greater (p = 0.0006) than for adults [14.8 (7.8) versus 10.6 (2.4) mL/min/kg]. When clearances from only children less than 10 years of age (N = 85) were compared with those from adults, the difference was even greater [15.6 (7.3) versus 10.6 (2.4) mL/min/kg; p = 0.0001]. However, when ICG CLp was normalized to body surface area, values for children did not differ significantly from adults [378 (204) versus 422 (102) mL/min/m2]. These data provide insight as to why dosage (mg/kg) requirements of certain drugs are higher in children.
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Affiliation(s)
- W E Evans
- Pharmacokinetics and Pharmacodynamics Section, St. Jude Children's Research Hospital, Memphis, TN
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35
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Abstract
During the last 15 years, several different groups of fastidious viruses that are responsible for a large proportion of acute viral gastroenteritis cases have been discovered by the electron microscopic examination of stool specimens. This disease is one of the most prevalent and serious clinical syndromes seen around the world, especially in children. Rotaviruses, in the family Reoviridae, and fastidious fecal adenoviruses account for much of the viral gastroenteritis in infants and young children, whereas the small caliciviruses and unclassified astroviruses, and possibly enteric coronaviruses, are responsible for significantly fewer cases overall. In addition to electron microscopy, enzyme immunoassays and other rapid antigen detection systems have been developed to detect rotaviruses and fastidious fecal adenoviruses in the stool specimens of both nonhospitalized patients and those hospitalized for dehydration and electrolyte imbalance. Experimental rotavirus vaccines have also been developed, due to the prevalence and seriousness of rotavirus infection. The small, unclassified Norwalk virus and morphologically similar viruses are responsible for large and small outbreaks of acute gastroenteritis in older children, adolescents, and adults. Hospitalization of older patients infected with these viruses is usually not required, and their laboratory diagnoses have been limited primarily to research laboratories.
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Affiliation(s)
- M L Christensen
- Department of Pathology, Northwestern University Medical School, Chicago, Illinois 60611
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36
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Christensen ML, Rivera GK, Crom WR, Hancock ML, Evans WE. Effect of hydration on methotrexate plasma concentrations in children with acute lymphocytic leukemia. J Clin Oncol 1988; 6:797-801. [PMID: 3163362 DOI: 10.1200/jco.1988.6.5.797] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [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: 01/04/2023] Open
Abstract
Hydration and urinary alkalinization are used with high-dose methotrexate (HDMTX) to minimize renal toxicity resulting from methotrexate (MTX) precipitation in the kidney tubules. The effect of two hydration and alkalinization schedules on MTX plasma concentrations were evaluated in 100 children with acute lymphocytic leukemia (ALL) following two courses of MTX, 2 g/m2. The mean 21- and 44-hour MTX plasma concentrations were significantly lower in the group receiving the greater hydration and alkalinization schedule: 0.79 (0.90 SD) v 1.39 (1.99 SD) mumol/L for 21-hour MTX plasma concentrations, P = .01; and 0.18 (0.38 SD) v 0.25 (0.50 SD) mumol/L for 44-hour MTX plasma concentrations, P = .01. Although the overall incidence of toxic events was similar in both groups, the incidence of severe toxicity was reduced in the group that received the greater hydration and alkalinization, 6% v 16%. This study demonstrated that the amount of hydration and alkalinization can affect MTX plasma concentrations. Optimizing the hydration and alkalinization schedule is important for minimizing the incidence of severe toxicity associated with HDMTX.
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Affiliation(s)
- M L Christensen
- Pharmaceutical Division, St. Jude Children's Research Hospital, Memphis, TN 38105
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37
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Christensen ML, Flanders R. Comparison of the Abbott and Ortho enzyme immunoassays and cell culture for the detection of respiratory syncytial virus in nasopharyngeal specimens. Diagn Microbiol Infect Dis 1988; 9:245-50. [PMID: 3053011 DOI: 10.1016/0732-8893(88)90116-2] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A comparison of the Abbott Laboratories and the Ortho Diagnostic Systems Respiratory Syncytial Virus (RSV) Enzyme Immunoassays (EIA) and HEp-2 cell culture for the detection of RSV in 81 nasopharyngeal (NP) specimens from pediatric patients with lower respiratory tract infection was carried out. The sensitivity and specificity of the Abbott test compared to confirmed infection was 92.3% and 100.0%, respectively. The sensitivity and specificity of the Ortho test was 87.5% and 80.3%, respectively. We found the Abbott EIA test to be sensitive, specific, rapid, and easy to perform.
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Affiliation(s)
- M L Christensen
- Department of Pathology, Northwestern University Medical School, Chicago, IL
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38
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Horowitz ME, Etcubanas E, Christensen ML, Houghton JA, George SL, Green AA, Houghton PJ. Phase II testing of melphalan in children with newly diagnosed rhabdomyosarcoma: a model for anticancer drug development. J Clin Oncol 1988; 6:308-14. [PMID: 3276826 DOI: 10.1200/jco.1988.6.2.308] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.4] [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: 01/05/2023] Open
Abstract
We describe events that led to successful testing of melphalan, one of the nitrogen mustard compounds, in children with newly diagnosed, poor-risk rhabdomyosarcoma (RMS). Preclinical studies with xenografts of human RMS, growing in the flanks of immune-deprived mice, had indicated superior oncolytic activity by melphalan compared with other agents commonly used to treat this tumor. However, in a conventional phase II trial, melphalan failed to produce partial responses in 12 of 13 heavily pretreated patients with recurrent tumors. Subsequent comparison of the drug's pharmacokinetics in mice and patients indicated that its poor clinical performance was not the result of interspecies differences in drug disposition. Therefore, we elected to retest melphalan in untreated patients, before they were enrolled in a phase III study. Of 13 children who received the drug for 6 weeks, ten had partial responses, confirming the significant antitumor activity seen in the xenograft system. These findings illustrate the inherent limitations of phase II drug trials in previously treated patients and suggest a useful paradigm for the development of antineoplastic drugs.
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Affiliation(s)
- M E Horowitz
- Department of Hematology-Oncology, St. Jude Children's Research Hospital, Memphis, TN
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Tucker JD, Christensen ML, Carrano AV. Simultaneous identification and banding of human chromosome material in somatic cell hybrids. Cytogenet Cell Genet 1988; 48:103-6. [PMID: 3197447 DOI: 10.1159/000132600] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We have developed a method that identifies human chromosomes in human x hamster somatic cell hybrids and simultaneously bands these same metaphases. Other methods generally require separate slides for banding and detection of human chromosome material, making the precise characterization of human material difficult. Our procedure involves denaturing metaphase chromosomes, followed by in situ hybridization of biotinylated whole human DNA. Fluoresceinated avidin is then bound to the biotinylated DNA, staining the human chromosomes yellow-green when excited with UV light. Chromosome banding is achieved by staining the slides with DAPI and actinomycin D. The fluorescein and DAPI excite maximally at 488 and 355 nm and emit at 520 and 450 nm, respectively. This permits identification of the human material at one excitation wavelength and visualization of the banding patterns at another wavelength. With this procedure, we have successfully identified both intact and broken human chromosomes, as well as human material involved in human x hamster translocations. The results indicate that this procedure is more accurate and considerably more rapid than previous methods and can be routinely employed for the cytogenetic analysis of human x rodent hybrids.
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Affiliation(s)
- J D Tucker
- Lawrence Livermore National Laboratory, Biomedical Sciences Division, University of California, Livermore 94550
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Thompson LH, Tucker JD, Stewart SA, Christensen ML, Salazar EP, Carrano AV, Felton JS. Genotoxicity of compounds from cooked beef in repair-deficient CHO cells versus Salmonella mutagenicity. Mutagenesis 1987; 2:483-7. [PMID: 3328038 DOI: 10.1093/mutage/2.6.483] [Citation(s) in RCA: 107] [Impact Index Per Article: 2.9] [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: 01/05/2023] Open
Abstract
A series of compounds isolated on the basis of their mutagenicity in the Ames/Salmonella reversion assay were previously identified in fried beef and chemically synthesized for further evaluation. In this study three of these compounds were tested for genotoxic effects in the UV5 line of Chinese hamster ovary (CHO) cells, which is deficient in nucleotide excision repair. Both 2-amino-3,4-dimethyl-imidazo]4,5-f]quinoline (MeIQ) and 2-amino-3,8-dimethyl-imidazo[4,5-f]quinoxaline (MeIQx) gave very weak responses for cell killing, hprt mutation induction and sister chromatid exchange. These effects occurred at doses in the range of 100-800 micrograms/ml (approximately solubility limit), and dose-dependent increases were not observed. Induction of chromosomal aberrations did not occur with either compound. Nor did either of these compounds produce differential cytotoxicity in normal CHO cells versus UV5 cells, indicating that potentially repairable DNA damage was not responsible for the observed cell killing. In contrast to these results, 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP), which constitutes greater than 90% of the mass of bacterial mutagens in beef, was strongly positive for all endpoints at doses in the range 1-3 micrograms/ml. PhIP also gave marked differential cytotoxicity (ratio of 6) and cell survival curves that were strongly dependent on repair capacity. Because PhIP is 50- to 300-fold less mutagenic than MeIQ and MeIQx in Salmonella TA1538, these results point to major differences between the bacterial and mammalian assays in terms of the relative potency of these food-related compounds.
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Affiliation(s)
- L H Thompson
- Biomedical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550
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41
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Stewart CF, Christensen ML, Evens RP, Cremer M, Evans WE. Influence of concomitant aspirin or prednisone on methotrexate synovial fluid concentration. J Pharmacol Exp Ther 1987; 243:131-7. [PMID: 3668846] [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: 01/06/2023] Open
Abstract
Methotrexate (MTX) is currently being used in the treatment of patients with rheumatoid arthritis. The purpose of this study was to investigate the effect of two classes of drugs, steroids and salicylates, on MTX synovial fluid concentrations. A novel canine model of monoarticular inflammation was used, in which each animal served as its own control with both inflamed and normal knees in the same animal. After the 6-week immunization process, animals in each group received either no drug (control), prednisone or aspirin (low dose and high dose) for 1 week before MTX. On the day of the study, each animal was given i.v. MTX, and serial serum and synovial fluid samples were obtained. Laboratory, histologic and clinical observations supported the presence of monoarticular inflammation. The end-of-infusion synovial MTX concentration in inflamed knees was significantly greater than in normal knees (P less than .05), but, 2 hr after the end of infusion, they were not different. The end-of-infusion ratio of synovial fluid MTX concentration to serum MTX concentration (both total and unbound) was significantly lower in the prednisone group than in the other treatment groups (P less than .05). The end-of-infusion ratio of the MTX synovial concentration in the inflamed knee compared with the normal knee at 2 hr was significantly lower in the prednisone group than in the other three treatment groups (P less than .05). These results have therapeutic implications for the use of MTX in treating rheumatoid arthritis.
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Affiliation(s)
- C F Stewart
- Department of Clinical Pharmacy, University of Tennessee, Memphis
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42
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Christensen ML. Development and use of functional client outcome measures. NLN Publ 1987:249-53. [PMID: 3684550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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43
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Choi T, Josten L, Christensen ML. Health-specific family coping index for noninstitutional care. NLN Publ 1987:161-7. [PMID: 3684529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Tucker JD, Christensen ML. Effects of anticoagulants upon sister-chromatid exchanges, cell-cycle kinetics, and mitotic index in human peripheral lymphocytes. Mutat Res 1987; 190:225-8. [PMID: 3102960 DOI: 10.1016/0165-7992(87)90034-0] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The effects of 3 blood anticoagulants, heparin, acid citrate dextrose (ACD), and ethylenediaminetetraacetic acid (EDTA) were investigated using human peripheral lymphocytes. Three different endpoints were examined: sister-chromatid exchange (SCE), cell kinetics index (CKI), and mitotic index (MI). SCEs were significantly increased in cells treated with EDTA, while the CKI and MI were significantly decreased in cultures treated with either ACD or EDTA when compared to cultures treated with heparin. These results suggest that anticoagulants may produce undesired effects upon cultured cells and indicate that the type of anticoagulant should be considered carefully prior to commencing cytogenetic studies using human peripheral lymphocytes.
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Crom WR, Glynn-Barnhart AM, Rodman JH, Teresi ME, Kavanagh RE, Christensen ML, Relling MV, Evans WE. Pharmacokinetics of anticancer drugs in children. Clin Pharmacokinet 1987; 12:168-213. [PMID: 3555940 DOI: 10.2165/00003088-198712030-00002] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Interpatient pharmacokinetic variability normally observed in adults is often of even greater magnitude in paediatric patients because of age-related maturation of physiological processes responsible for drug disposition. Several antineoplastic agents have shown age-related changes, including alterations in volume of distribution, hepatic (doxorubicin, cyclophosphamide), and renal (bleomycin, methotrexate) clearances. These differences in pharmacokinetics as a function of age alter systemic exposure to chemotherapy, and may alter the efficacy and toxicity profile for standard doses of antineoplastic drugs. The relationship of systemic exposure to toxicity has been most clearly defined for methotrexate. Clinical monitoring of methotrexate serum concentrations, and adjustment of folinic acid dosages and duration of rescue based on methotrexate disposition is now routine. More recently, pharmacodynamic data have been published for high-dose methotrexate, epipodophyllotoxins, cisplatin, and cytarabine (cytosine arabinoside), indicating a relation between drug disposition and toxicity or efficacy. Collectively, these data suggest that the pharmacokinetics of many anticancer drugs in children is different from adults, and that variability in drug disposition may have an important influence on toxicity or efficacy.
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Helms RA, Christensen ML, Mauer EC, Storm MC. Comparison of a pediatric versus standard amino acid formulation in preterm neonates requiring parenteral nutrition. J Pediatr 1987; 110:466-70. [PMID: 3102712 DOI: 10.1016/s0022-3476(87)80519-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Helms RA, Whitington PF, Mauer EC, Catarau EM, Christensen ML, Borum PR. Enhanced lipid utilization in infants receiving oral L-carnitine during long-term parenteral nutrition. J Pediatr 1986; 109:984-8. [PMID: 3097293 DOI: 10.1016/s0022-3476(86)80281-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Fourteen infants requiring long-term total parenteral nutrition but able to tolerate small quantities of enteral feedings were randomized into carnitine treatment and placebo control groups. All infants had received nutritional support devoid of carnitine. Plasma carnitine levels and observed plasma lipid indices were not different before supplementation. Under standardized, steady-state conditions, 0.5 g/kg fat emulsion (intralipid) was administered intravenously over 2 hours both before and after infants received 7 days of continuous nasogastric or gastric tube L-carnitine (50 mumol/kg/day) or placebo. Plasma triglyceride, free fatty acid, acetoacetate, beta-hydroxybutyrate, and carnitine concentrations were observed at 0 (start of lipid infusion), 2, and 4 hours for pre- and post-treatment periods, and in addition at 6 and 8 hours after carnitine supplementation. Infants receiving carnitine had significantly greater beta-hydroxybutyrate plasma concentrations (P less than 0.05) and carnitine (P less than 0.001) at 0, 2, 4, 6, and 8 hours, and greater plasma acetoacetate concentrations (P less than 0.05) at 2, 4, 6, and 8 hours, compared with controls. Twenty-four-hour urinary carnitine excretion was very low for both groups before supplementation; after supplementation, excretion was higher (P less than 0.05) in the carnitine group. No significant differences were found between groups for plasma triglyceride or free fatty acid concentrations at any observation period. This study demonstrated enhanced fatty acid oxidation, as evidenced by increased ketogenesis, with L-carnitine supplementation in infants receiving long-term total parenteral nutrition.
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Christensen ML, Pachman LM, Schneiderman R, Patel DC, Friedman JM. Prevalence of Coxsackie B virus antibodies in patients with juvenile dermatomyositis. Arthritis Rheum 1986; 29:1365-70. [PMID: 3022759 DOI: 10.1002/art.1780291109] [Citation(s) in RCA: 127] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A number of viruses have been implicated as being the cause of various forms of myositis, including acute transient myositis, chronic polymyositis, and dermatomyositis. However, the cause of juvenile dermatomyositis (JDM) has remained elusive. Our study of serum samples taken within 4 months of the onset of disease in 12 children with JDM showed that 83% had detectable titers of complement-fixing (CF) antibody to 1 or more coxsackie B viral antigens. Detectable titers were found in only 25% of age-, sex-, and date-matched control sera taken from 24 patients with juvenile rheumatoid arthritis (JRA), and in 25% of serum samples taken from 2,192 "normal" children who had been hospitalized because of viral syndromes. Titers of CF antibody to coxsackie B1, B2, and B4 were positive in 58%, 50%, and 58%, respectively, of the JDM patients. In matched JRA controls, the respective values were 8%, 13%, and 8%. There were no significant antiviral titers and no significant differences in the results of tests for 13 other viral CF antigens, hepatitis B surface antigen, and Mycoplasma pneumoniae CF antigen in the JDM patient sera compared with the JRA patient sera. When titers of neutralizing antibody were determined, 58%, 58%, and 67% of the JDM patients were positive for coxsackie B2, B4, and B5, respectively, whereas 16%, 26%, and 21%, respectively, of the JRA controls were positive for the 3 antigens. These data suggest that the host response to coxsackie B virus might be related to the pathophysiology of JDM.
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Helms RA, Dickerson RN, Ebbert ML, Christensen ML, Herrod HG. Retinol-binding protein and prealbumin: useful measures of protein repletion in critically ill, malnourished infants. J Pediatr Gastroenterol Nutr 1986; 5:586-92. [PMID: 3090221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Plasma prealbumin (PA) and retinol-binding protein (RBP) concentrations were serially measured in 25 critically ill, malnourished infants requiring parenteral nutrition to determine if these visceral protein markers are useful in assessing acute protein repletion. Significant increases in both proteins (p less than 0.05) were noted as early as 5 to 7 days after institution of parenteral nutrition and continued significantly above baseline values through 2 weeks of observation. Gestational development (in infants less than 4 weeks old) and mean protein intake influenced visceral protein responses. Appropriate for gestational age neonates had more rapid and quantitatively greater PA responses (p less than 0.05) than small for gestational age neonates. Small for gestational age neonates never exceeded baseline RBP responses. Average protein intake of less than or equal to 2 g/kg/day resulted in PA and RBP concentrations below baseline and significantly lower than infants on higher protein intakes (p less than 0.05), at the end of 2 weeks. Average calorie intake of greater than 100 cal/kg/day had no differential influence on PA or RBP when compared with infants on less calories. Prealbumin values correlated with RBP values observed simultaneously (r = 0.588, p less than 0.0001). We conclude that PA and RBP are useful measures of protein repletion in critically ill infants requiring parenteral nutrition.
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Tucker JD, Christensen ML, Strout CL, Carrano AV. Determination of the baseline sister chromatid exchange frequency in human and mouse peripheral lymphocytes using monoclonal antibodies and very low doses of bromodeoxyuridine. Cytogenet Cell Genet 1986; 43:38-42. [PMID: 2430761 DOI: 10.1159/000132295] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We measured the frequency of sister chromatid exchanges (SCEs) in human and mouse peripheral lymphocytes using doses of bromodeoxyuridine (BrdU) ranging from 30 nM to 100 microM (human) and from 10 nM to 10 microM (mouse). Heparinized peripheral blood was obtained from five healthy nonsmokers and from six C57B1/6 male mice. The blood was stimulated with PHA (human) or lipopolysaccharide (LPS, mouse) and grown for the first of two cell cycles in BrdU. Metaphase chromosomes were denatured and exposed to a monoclonal antibody reactive to single-stranded DNA containing BrdU. A second antibody was used to label the first antibody with fluorescein, and propidium iodide was used as a counterstain. Second-division metaphases were thus differentially stained red to indicate DNA content and yellow-green to indicate the presence of BrdU. The results indicate that the baseline SCE frequency in human and mouse peripheral lymphocytes is 3.6 and 2.4 SCEs per cell per generation, and that in the human these frequencies are invariant at the lowest BrdU levels. This suggests that SCEs are an integral part of DNA replication, even in the absence of agents known to induce SCEs. The distribution of SCEs per chromosome was analyzed and found to be Poisson-distributed in all 24 murine cultures and in 25 of 36 human cultures. The distribution of SCEs per chromosome may be due to either species-specific chromosome packaging or to karyotypic differences between the species.
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