Clinical and immunological characteristics and prognosis of patients with autoantibody negative dermatomyositis: a case control study

OBJECTIVES

Myositis-specific antibodies (MSAs) and myositis-associated antibodies (MAAs) are associated with distinctive dermatomyositis (DM) clinical phenotypes. The aim of this study is to explicate the clinical and immunological features of MSAs-negative DM patients.

METHODS

A total of 515 individuals diagnosed with DM was screened from 2013 to 2022 and 220 DM patients were enrolled in this retrospective cohort. Clinical and laboratory data of these patients were analyzed.

RESULTS

MSAs-negative DM patients were categorized into two groups: MAAs-negative (MSAs (-)/MAAs (-)) group and MAAs-positive (MSAs (-)/MAAs (+)) group. The percentage of Raynaud's phenomenon (P=0.026) was higher in the MSAs (-)/MAAs (+) DM patients than the MSAs-positive DM patients and MSAs (-)/MAAs (-) DM patients. The proportion of rapidly progressive interstitial lung disease (RP-ILD) in the MSAs-negative DM patients was lower than that in the MSAs-positive group. The MSAs (-)/MAAs (+) group had a higher proportion of organizing pneumonia and usual interstitial pneumonia (P=0.011), and elevated eosinophils in their bronchoalveolar lavage fluid (P=0.008). Counts of lymphocytes (P=0.001) and CD16+CD56+ natural killer (NK) cells (P=0.012) were higher in the MSAs-negative group. Additionally, the percentage of CD4+TNFα+ (P=0.040), CD4+IFNγ+ (P=0.037), and CD4+IL-2+ (P=0.018) cells among total CD4+ T cells were higher in the MSA-negative DM patients compared with the MSAs-positive DM patients. Besides, MSAs-negative patients demonstrated a more favorable prognosis than MSAs-positive patients. Multivariable regression analysis identified advanced onset age, higher level of carcinoembryonic antigen (CEA), and RP-ILD as risk factors for mortality in DM patients.

CONCLUSIONS

Compared with MSAs-positive group, MSAs-negative DM patients suffered less from organ involvement compared with MSAs-positive group and tend to have better prognosis. Key Points MSAs-negative DM patients exhibited distinct characteristics in comparison with MSAs-positive DM patients:   • The MSAs (-)/MAAs (+) DM patients demonstrated a higher prevalence of organizing pneumonia (OP) and usual interstitial pneumonia (UIP), and elevated eosinophil counts in bronchoalveolar lavage fluid.   • CEA levels were lower in MSAs-negative patients compared with MSAs-positive patients.   • Elevated counts of lymphocytes and CD16+CD56+ NK cells were identified in the MSAs-negative patients. Additionally, proportions of CD4+TNFα+, CD4+IFNγ+, and CD4+IL-2+ cells among total CD4+ T cells were higher in the MSAs-negative DM patients compared with DM MSAs-positive DM patients.   • MSAs-negative DM patients had a more favorable prognosis than MSAs-positive DM patients. A multivariable regression analysis revealed the advanced onset age, high CEA levels, and RP-ILD were risk factors for mortality in DM patients.

MicroRNA-206 Contributes to the Progression of Preeclampsia by Suppressing the Viability and Mobility of Trophocytes via the Inhibition of AGTR1

The development of preeclampsia (PE) is associated with the impaired trophoblast motility. MicroRNAs (miRs) contribute to the modulation of trophoblast invasion. In the current study, the role of miR-206/AGTR1 in the TNF-alpha-induced invasion defect of trophoblasts was explored. The levels of miR-206 and ATGR1 in clinical placenta tissues were investigated. Trophoblasts were treated with TNF-alpha, and the levels of miR-206 and ATGR1 were modulated. Changes in cell viability, invasion, and inflammation in trophoblasts were detected. The level of miR-206 was induced, while the level of AGTR1 was suppressed in placenta tissues. In in vitro assays, TNF-alpha suppressed viability, induced inflammatory response, inhibited invasion, upregulated miR-206, and down-regulated AGTR1. The inhibited expression of miR-206 or the overexpression of AGTR1 counteracted the effects of TNF-alpha, indicating the key role of the miR-206/AGTR1 in progression of PE. Collectively, miR-206 suppressed viability, induced inflammatory response, and decreased invasion of trophoblasts by inhibiting AGTR1.

Can we assess severity of Guillain-Barré syndrome using absolute monocyte count?

INTRODUCTION

Guillain-Barré syndrome (GBS) is an inflammatory demyelinating autoimmune disease, associated with blood-nerve barrier breakdown, inflammatory cells infiltration, and cytokine leakage in the peripheral nervous system. Currently, it has been revealed that monocytes play key roles in the inflammatory response. Therefore, we aimed to assess the correlation between monocyte count and GBS in this study.

METHODS

Retrospective study was conducted in 114 patients with GBS and 120 age- and gender-matched individuals.

RESULTS

Absolute monocyte count in patients with GBS was higher than that in healthy controls (0.61 ± 0.24 vs 0.41 ± 0.10; P  < .001). Interestingly, monocyte count had significant positive correlations with CRP, ESR, and disease severity of GBS (r = .244, P = .009; r = .269, P = .004; r = .322, P < .001). A cutoff value of 0.515 for monocyte count was observed in patients with GBS (areas under the curve = 0.808, 95% confidence interval = 0.749-0.868, P  < .001). Meanwhile, absolute monocyte count was independently associated with GBS in logistic regression analysis (odds ratio = 2.291, 95% confidence interval = 3.557-27.493, P < .001).

CONCLUSION

Our findings demonstrated that elevated monocyte count is independently associated with GBS patients, and suggested monocyte count is positively associated with disease severity of GBS.

Molecular alterations of the WWOX gene in nasopharyngeal carcinoma

The WW domain-containing oxidoreductase (WWOX) gene is a candidate tumor suppressor gene. However, its exact mechanism is unclear. This study aimed to investigate the role of the WWOX gene in the development of nasopharyngeal carcinoma (NPC). Tissues were collected from 65 NPC patients. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis and immunohistochemistry were performed on NPC tissues to determine the expression of WWOX in NPC. The status of WWOX promoter methylation was analyzed by methylation-specific PCR. Moreover, a PCR-based loss of heterozygosity (LOH) assay was conducted to detect the presence of WWOX deletion in NPC. The expression of WWOX in NPC tissues was significantly downregulated compared with that in non-tumorous tissues (P<0.05). The low expression of WWOX was significantly correlated with clinical TNM stage (P<0.05). In addition, methylation of WWOX was detected in 27 (87%) of 31 WWOX protein negative tissues, suggesting that methylation of the WWOX promoter may regulate its expression. We found that a relatively high percentage of LOH was observed in NPC tissues. A significant inverse correlation between WWOX expression and methylation of its promoter was found in NPC tissue (rs=-0.582, P=0.001). However, LOH was not correlated with WWOX expression and methylation of its promoter. Our results show that WWOX gene alteration is an early genetic alteration and may contribute to tumorigenesis of NPC. WWOX may be an important prognostic marker in NPC.

Coagulation factor III (tissue factor) is required for vascularization in zebrafish embryos

Tissue factor (coagulation factor III) is a cell surface receptor for coagulation factor VII/VIIa; it was initially recognized as an initiator of the extrinsic coagulation pathway. Recently, the zebrafish tissue factor gene (TF) has been cloned. Paralogs encode coagulation factors IIIa and IIIb; both show remarkable sequence identity to the human and mouse coagulation factor III gene. It has been reported that TF could have additional properties that are essential for normal embryonic development, since knockout of the murine coagulation factor III gene resulted in 90% embryonic lethality. We examined the role of coagulation factor IIIb (f3b) during zebrafish embryonic development. Expression analysis revealed that endogenous f3b was chronologically expressed in the pectoral fins and in the vicinity of the pharynx. Knockout of f3b by injection of an f3b morpholino at the one-to-two cell stage caused distinctive morphological defects in embryos, including edema in the fourth brain ventricle at early embryonic stages and occasional bleeding at later stages. Furthermore, f3b morphants displayed abnormal vascular patterning. We conclude that f3b is required for brain vascular development and for development of part of the somatic vasculature during embryogenesis in the zebrafish.

Hyaluronan oligosaccharides are potential stimulators to angiogenesis via RHAMM mediated signal pathway in wound healing

Purpose: To determine if oligosaccharides of hyaluronan (o-HA) promotes wound recovery by accelerating angiogenesis and to study the mechanisms by which o-HA stimulates endothelial cell (EC) proliferation. Methods: Using hyaluronidase digestion, we prepared a mixture of hyaluronan (HA) fragments sizesd 2 to 10 disaccharides units, and studied their effects on EC growth and migration in mimicking wound recovery in vitro. The effects of o-HA on EC growth in vitro were studied by counting cell numbers. The roles of 2 hyaluronan receptors on EC cells, CD44 and RHAMM (Receptor for HA-Mediated Motility), were studied in initiating signaling cascades, using immunoblot assay. Signal transduction was determined by blocking antibodies to CD44 and RHAMM. An in vitro wound healing model was prepared by scratching the cellular layer of cultured EC, and movement of cells into the denuded area was quantified. Results: o-HA was a strong stimulator to EC proliferation at low concentration 10µg/ml compared with native high molecular weight HA (n-HA) (P < 0.01). Signal transduction may be initiated by o-HA via RHAMM receptor on EC membrane, but not CD44. In the in vitro model, the lesion area was nearly completely recovered when the EC layer was exposed to o-HA 40hrs post-injury, whereas the wound area remained half recovered pretreated with native undegraded large HA and control medium.(P < 0.05 from 24 to 40hrs). Conclusion: Hyaluronan oligosaccharides may play a role in wound healing by increasing angiogenesis. o-HA-RHAMM binding dependent signal transduction pathway may be important in the regulation of angiogenesis associated with EC proliferation.

Enzymatic vitreolysis with recombinant microplasminogen and tissue plasminogen activator

PURPOSE

To generate microplasmin (microPlm) using recombinant microplasminogen (microPlg) and recombinant tissue plasminogen activator (rt-PA) before intravitreous injection and to investigate the efficacy of microPlm in inducing posterior vitreous detachment (PVD).

METHODS

Forty-eight female or male New Zealand white rabbits were randomized into three groups. Recombinant human microPlg was incubated with rt-PA with a 200:1 molar ratio at 37 degrees C for 40 min. The right eyes of groups 1, 2, and 3, were injected with 0.5, 1.0, and 1.5 U microPlm in 0.1 ml respectively, and 0.1 ml balanced salt solution (BSS) was injected into the left eye as controls. Scanning electron microscopy (SEM), gross specimen examination, B-ultrasonography and optical coherence tomography (OCT) were performed to detect vitreoretinal interface.

RESULTS

Over eighty percent of recombinant human microPlg could be activated to active microPlm by rt-PA after 40 min incubation. Complete PVD was found at vitreous posterior pole of microPlm-treated eyes without morphological change of retina. Complete PVD of 25, 75, and 87.5% rabbit eyes was induced by 0.5, 1.0 and 1.5 U recombinant microPlm respectively on day 1. The remnants of vitreous cortex at the posterior pole were dependent on the concentration of microPlm. Among the four approaches for detecting PVD, SEM, gross specimen examination, and B-ultrasonography were more effective methods than OCT.

CONCLUSION

Intravitreous injection of 1.5 U microPlm can effectively induce complete PVD in rabbit eyes on day 1 without morphological change of retina.

Sustained and stable hematopoietic donor-recipient mixed chimerism after unrelated cord blood transplantation for adult patients with severe aplastic anemia

We evaluated the engraftment of donor cells from unrelated cord blood into adult patients with severe aplastic anemia (SAA) and the outcome of allo-CBSCT (cord blood stem cell transplantation). Nine patients were conditioned with decreased dosage of immunosuppressive agents of CTX (60 mg/kg) and ALG (120 mg/kg). The prophylaxis of GVHD consisted of standard CsA and MTX. Patients have a media age of 25.3 yr (range: 15-37), and a median weight of 57.2 kg (range: 52.5-60) at the time of transplantation. Cord blood searches were all conducted at Guangzhou Cord Blood Bank. The engraftment state of the donor cells into recipients was confirmed by microsatellite DNA fingerprinting and fluorescent quantitative PCR analysis. Engrafted evidence has been found in seven patients involved by biomolecular analyses showing donor-recipient mixed chimerism post-transplant which was stable and persistent. After a median follow up of 32.2 months (range: 4-69), seven patients were alive and disease free. This study shows that durable donor-recipient stable mixed chimerism can be achieved by unrelated CBSCT in patients with SAA. Umbilical cord blood could be employed as a source of hematopoietic stem cell for adult transplantation.

Umbilical cord blood transplant for adult patients with severe aplastic anemia using anti-lymphocyte globulin and cyclophosphamide as conditioning therapy

Allo-CBSCT (cord blood stem cell transplant) has been applied in six adult patients with severe aplastic anemia (SAA). Anti-lymphocyte globulin (ALG) 40 mg kg(-1) d(-1) x 3 days combined with cyclophosphamide (CTX) 20 mg kg(-1) d(-1) x 3 days constituted a lower intensive conditioning regimen. The prophylaxis of GVHD consisted of standard CsA and MTX. Patients are all male having a mean age of 26.5 years (range 22-38), and a median weight of 55.6 kg (range 52-60 kg). Cord blood searches were all conducted at Guangzhou Cord Blood Bank. Three of six patients in our study received one unit of cord blood in a procedure, whereas for another three patients, two units of cord blood (double units) were infused at the same time in a transplant protocol. The nine units of umbilical cord blood (UCB) infused contained 1.6-10.7 x 10(7) nucleated cells/kg body weight of the recipient after thawing. HLA antigens were identical in one unit, 1 antigen mismatched in seven, 2 antigens mismatched in 1. As of February 2003, after a median follow up of 20 months (range 7-50), four patients are alive and disease free. Five patients engrafted with molecular biology analyses showing donor-recipient mixed chimerism post transplant which is stable and persistent. One patient died of severe infection in the third month from transplant and another patient died in the early stage post transplant of serious aspergillus infection without evidence of engraftment.

Preparation and mass spectrometric study of egg yolk antibody (IgY) against rabies virus

Rabies virus was used as the antigen to immunize laying chickens. Anti-rabies virus immunoglobulin Y(IgY) was isolated from yolks of the eggs laid by these chickens using a two-step salt precipitation and one-step gel filtration protocol. The purified IgY was reduced with dithiothreitol, and heavy chains (HC) and light chains (LC) were obtained. In addition, the purified IgY was digested with pepsin and the fragment with specific antigen binding properties (Fab) was produced. Using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOFMS), the average molecular weights of IgY, HC, LC, and Fab were determined as 167 250, 65 105, 18 660, and 45,359 Da, respectively. IgY has two structural differences compared with mammalian IgGs. First, the molecular weight of the heavy chain of IgY is larger than that of its mammalian counterpart, while the molecular weight of the light chain of IgY is smaller. Second, upon pepsin digestion, anti-rabies virus IgY is degraded into Fab, in contrast to mammalian IgG, which has been reported to be degraded into F(ab')(2) under the same conditions.

Characterization of phosphopeptides from protein digests using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nanoelectrospray quadrupole time-of-flight mass spectrometry

A two-step mass spectrometric method for characterization of phosphopeptides from peptide mixtures is presented. In the first step, phosphopeptide candidates were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) based on their higher relative intensities in negative ion MALDI spectra than in positive ion MALDI spectra. The detection limit for this step was found to be 18 femtomoles or lower in the case of unfractionated in-solution digests of a model phosphoprotein, beta-casein. In the second step, nanoelectrospray tandem mass (nES-MS/MS) spectra of doubly or triply charged precursor ions of these candidate phosphopeptides were obtained using a quadrupole time-of-flight (Q-TOF) mass spectrometer. This step provided information about the phosphorylated residues, and ruled out nonphosphorylated candidates, for these peptides. After [(32)P] labeling and reverse-phase high-performance liquid chromatography (RP-HPLC) to simplify the mixtures and to monitor the efficiency of phosphopeptide identification, we used this method to identify multiple autophosphorylation sites on the PKR-like endoplasmic reticulum kinase (PERK), a recently discovered mammalian stress-response protein.

Use of nitrocellulose films for affinity-directed mass spectrometry for the analysis of antibody/antigen interactions

Combination of affinity extraction procedures with mass spectrometric analyses is termed affinity-directed mass spectrometry, a technique that has gained broad interest in immunology and is extended here with several improvements from methods used in previous studies. A monoclonal antibody was immobilized on a nitrocellulose (NC) membrane, allowing the corresponding antigen to be selectively captured from a complex solution for analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). This method was also used to rapidly determine the approximate binding region responsible for the antibody/antigen interaction. The tryptic fragments of antigen protein in buffer were applied to the antibody immobilized on NC film and allowed to interact. The NC film was then washed to remove salts and other unbound components, and subjected to analysis by MALDI-TOFMS. Using interferon-alpha(2a) and anti-interferon-alpha(2a) monoclonal antibody IgG as a model system, we successfully extracted the antigen protein and determined the approximate binding region for the antigen/antibody interaction (i.e., the tryptic fragment responsible).

Umbilical cord blood transplantation from unrelated HLA-matched donor in an adult with severe aplastic anemia

A 23-year-old male suffering from severe aplastic anemia (SAA) weighing 60 kg was successfully treated by unrelated allo-CBSCT (cord blood stem cell transplantation). A six-loci HLA-identical umbilical cord blood (UCB) was infused after conditioning with low-dose cyclophosphamide (CTX) and antilymphocyte globulin (ALG). The prophylaxis of GVHD consisted of CsA and MTX. The infused cord blood provided 1.89 x 10(7) nucleated cells per kg, CD34-positive cells: 0.89%. Neutrophils >0.5 x 10(9)/l were reached 10 days after transplant, and platelets greater than 50.0 x 10(9)/l at day 26. RBC and platelet transfusion independence were reached on days 15 and 18. The patient developed grade 1 skin GVHD 10 months after engraftment of the donor cells. Microsatellite DNA fingerprinting indicated a stable and persistent donor-recipient mixed chimerism, whilst the circulating red cells remain of host origin.

[Umbilical cord blood stem cells transplantation from an unrelated donor into an adult with severe aplastic anemia]

OBJECTIVE

To evaluate the availability of the treatment of adult severe aplastic anemia with unrelated allo-cord blood stem cell transplantation (CBSCT).

METHODS

HLA-matched unrelated cord blood transplantation has been successfully performed for an adult severe aplastic anemia patient. A unit of cord blood provided by Guangzhou Cord Blood Bank containing 1.89 x 10(7)/kg mononucleated cells, 1.8 x 10(4)/kg CFU-GM and of CD(34) positive cells was 0.009. The patient was conditioned with CTX (60 mg/kg) and anti-lymphocyte globulin (ALG, 120 mg/kg). GVHD prophylaxis consisted of both MTX and CsA. The CsA had been given for 8 months.

RESULTS

The lowest ANC was 0.6 x 10(9)/L post-transplantation. The patient achieved an ANC of greater than 0.5 x 10(9)/L at 10 days, and the platelet of greater than 50.0 x 10(9)/L at day 20 after transplantation. He developed Grade 1 GVHD in the tenth month after grafting. Microsatellite DNA fingerprinting indicated a stable donor-recipient mixed chimerism, whilst the circulating red cells remained host origin.

CONCLUSION

It is the first report in China on successful treatment of adult severe aplastic anemia by unrelated allo-CBSCT.

[Clinical analysis of 106 cases of inhalation injury induced by gas explosion]

OBJECTIVE

To review the management of inhalation injury induced by gas explosion in our department, so as to draw some experience and lessons for future work.

METHODS

One hundred and six cases of inhalation injury induced by gas explosion were analyzed in terms of the characteristics of and therapeutic methods for the disease.

RESULTS

The injury induced by gas explosion was very complicated with high incidences of compound injuries, severe inhalation injury and systemic infection. In addition, respiratory dysfunction occurred very quickly and severely at early postburn stage, which could easily develop to respiratory failure. The latter could ultimately lead patients to death due to improper management.

CONCLUSION

In order to raise cure rate of the inhalation injury induced by gas explosion, airway obstruction should be cleared immediately and fiberbronchoscopy and respirator should be employed as soon as possible to help remove endotracheal obstruction and to maintain effective gas exchange. In addition, correct pulmonary resuscitation and continuous blood gas analysis were advocated.

Novel rearranged ions observed for protonated peptides via metastable decomposition in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

C-terminal rearrangement ions [b(n-1) + H2O] (where n refers to the total number of residues of peptides) are frequently observed for peptides which contain basic amino acid(s), especially arginine, at or near their N termini in low- and high-energy collision-induced dissociation or post-source decay (PSD) spectra. Here we report a novel rearrangement, associated with PSD for serine- or threonine-containing peptides that are susceptible to C-terminal rearrangement. Based on PSD analyses of serine- or threonine-containing bradykinin and its analogs, which have been ethyl-esterified or 18O labeled at their C termini, the [b(k) + H2O] (where k denotes the position adjacent to the left of the Ser/Thr residue) ion is generally thought to be formed by the transfer of the hydroxyl moiety of a serine or threonine residue to the carbonyl group of the residue to its left accompanied by the loss of the remaining C-terminal portion of the peptide. When the Ser/Thr is at or near the C terminus, the present [b(k) + H2O] ion could be formed via two pathways, i.e., the Ser/Thr-related rearrangement and the conventional C-terminal rearrangement, which has been clearly verified by 18O labeling at the C terminus. In addition, the ions which are formally designated as [y(m)b(l) + H2O], where y(m)b(l) denotes a b-type internal ion, are also briefly described.

Structural characterization of chemically derivatized oligosaccharides by nanoflow electrospray ionization mass spectrometry

Oligosaccharides released from several glycoproteins were derivatized with either 4-aminobenzoic acid 2-(diethylamino)ethyl ester (ABDEAE) (Yoshino, K.; et al. Anal. Chem. 1995, 67, 4028-4031) or 2-aminopyridine. The resulting derivatives were analyzed on a nanoflow electrospray ionization (ESI) quadrupole-inlet time-of-flight mass spectrometer using the low-energy collision-induced dissociation technique. In the MS/MS spectra, the oxonium (b or internal series) and y series ions, which are derived from the multiply charged precursor ions, were predominant and were used for the structural readout. Some oxonium ions that were observed in the low-mass region, but that were not found in the PSD analyses (Mo, W.; et al. Anal. Chem. 1998, 70, 4520-4526), rendered a more detailed structural insight. The oxonium ions at m/z 512.2, which are derived from the fucosylated oligosaccharides of immunoglobulin Y and thyroglobulin, were observed, suggesting that fucosylation had occurred proximal to the outer nonreducing terminus. In addition, the data herein show that structural elucidation can be routinely achieved at a low sample concentration. For the case of ABDEAE derivatives, this can be achieved at the 50 fmol/microL level and with the actual sample consumption at the attomole level using nanoflow ESI MS/MS.

Cocaine-induced hypertension: role of the peripheral sympathetic system

Cocaine causes hypertension at least in part by stimulating the sympathetic nervous system, but it is not clear if this effect is centrally or peripherally mediated. To address this issue we studied the vasoconstrictive effect of cocaine in vivo and in isolated artery segments. In vivo cocaine increased mean arterial blood pressure (MAP) by 40 mmHg within 1 min of administration. Pretreatment with prazosin blocked this response by 62%. With clonidine the pre-cocaine MAP was lower and the hypertensive effect of cocaine was blocked by 50%, indicating an important role for central alpha-adrenergic mechanisms. In isolated rat carotid arteries cocaine-induced vasoconstriction was completely blocked by prazosin, phentolamine, and 6-hydroxydopamine, indicating a clear role for a peripheral effect. However, the relative contribution of the central alpha-adrenergic mechanism to the total vasoconstrictive response of cocaine was not clarified. 1999 Academic Press.

Changes in collagenases and TGF-beta precede structural alterations in a model of chronic renal fibrosis

BACKGROUND

To study the role of collagenases and transforming growth factor-beta (TGF-beta) in the genesis of interstitial fibrosis, we used the model of bromoethylamine (BEA)-induced papillary necrosis, which is known to lead over a period of 1 to 12 months to interstitial fibrosis and renal insufficiency.

METHODS

Rats were injected with BEA, and urine and kidney tissue (cortex and medulla) were collected after 1, 2, 3, 7, and 30 days. One kidney was perfused and fixed for morphological studies and immunostained for collagen type I, III, and IV. The other kidney was used to prepare cortex and medulla extracts for gelatinases (by fluorometric and zymographic techniques), tissue inhibitors of metalloproteinase-1 (TIMP-1), and TIMP-2 (by enzyme-linked immunosorbent assay, ELISA) and TGF-beta1 (by ELISA).

RESULTS

Albuminuria and interstitial fibrosis were present in BEA rats by day 7, which continued until day 30. Immunocytochemical staining for collagen types showed that collagen III and IV increased in the interstitium by day 30, but collagen I remained unchanged. Gelatinase activity in the medulla decreased by 57% compared with control by day 2 and remained low until day 30. In the cortex, gelatinase activity remained unchanged between 0 and 7 days after BEA but decreased by 72% by day 30. TIMP-1 and TIMP-2 were decreased by 80% compared with day 0 in both the medulla (by day 1) and cortex (by day 2) and remained low up to day 30. TGF-beta1 immunoreactivity increased progressively until day 2 in the medulla (16-fold higher than control) and day 3 in the cortex (8-fold higher than control) and returned to control level by day 3 in the medulla and by day 30 in the cortex. Two days after BEA injection, the mRNA for TGF-beta1 was increased eightfold in the cortex and 12-fold in the medulla, and it remained high for up to 30 days.

CONCLUSIONS

The fibrosis that follows papillary necrosis is associated with both high TGF-beta1 expression and depressed gelatinolytic activity.

Carbamylated proteins activate glomerular mesangial cells and stimulate collagen deposition

Carbamylated proteins formed in renal insufficiency from the spontaneous decomposition of urea exert a variety of metabolic effects. Here we examined the effects of carbamylated proteins on glomerular mesangial cells to determine whether urea retention in early renal insufficiency may itself promote glomerular sclerosis and hasten the progression to kidney failure. To this effect we carbamylated fetal bovine serum proteins in vitro and tested their effect on mesangial cell proliferation (by tritiated thymidine uptake), de novo protein synthesis (by tritiated leucine uptake), collagen I and collagen IV accumulation (by avidin-biotin enzyme immunoassay), and gelatinase levels in the medium (by zymography and quantitative fluorescence assay). Carbamylated fetal bovine serum at concentrations present in uremia increased tritiated thymidine incorporation by 50% without altering tritiated leucine incorporation, and it increased collagens I and IV in the monolayer by 150% to 300%. Gelatinase activity was unchanged. We conclude that carbamylated proteins can activate mesangial cells to a profibrogenic phenotype. From a clinical perspective, the carbamylation of proteins by elevated urea levels may accelerate the progression to kidney failure and thus set up a vicious cycle in which the nitrogen retention itself would cause further progression of fibrosis and deterioration of kidney function.

Structural analysis of oligosaccharides derivatized with 4-aminobenzoic acid 2-(diethylamino)ethyl ester by matrix-assisted laser desorption/ionization mass spectrometry

Oligosaccharides derivatized with 4-aminobenzoic acid 2-(diethylamino) ethyl ester (ABDEAE) can be analyzed by ESI (Yoshino, K.; et al. Anal. Chem. 1995, 67, 4028-4031) and MALDI (Takao, T.; et al. Rapid Commun. Mass Spectrom. 1996, 10, 637-640) mass spectrometry. In this study, oligosaccharides derived from the enzymatic cleavage of the sugar chains of glycoproteins ribonuclease B, erythropoietin, and transferrin were subjected to ABDEAE derivatization, prior to analysis on a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS) for high-resolution mass measurement and a postsource decay (PSD) experiment. In the mass measurement of ABDEAE derivatives, quasi-molecular ion species have been observed in monoisotopic resolution using 2,5-dihydroxybenzoic acid as the matrix from spots that contain 50-200 fmol of sample; in the PSD analyses from the spots contained 500 fmol-1 pmol of sample, the predominant backbone ion series which covers the entire mass range for all the derivatives, the internal ion series which reflect the branched trimannosyl core structure of N-glycans, and the low m/z fingerprint ion of ABDEAE were consecutively observed, permitting structure elucidation of the oligosaccharides. Given the effectiveness of this derivatization in terms of its high sensitivity and resolution with respect to MALDI-TOF MS, current methodology is clearly applicable to the sensitive detection and accurate structural analysis of N-glycans.

Role of nitric oxide in cocaine-induced acute hypertension

Cocaine causes acute hypertension by blocking catecholamine reuptake. There is evidence that it also impairs the peripheral endothelial nitric oxide system, which is normally vasodilatory. We further explored the role of nitric oxide in cocaine-induced vasoconstriction in anesthetized rats, and in vitro by using isolated carotid artery segments. Cocaine administered intravenously in rats increased mean arterial pressure by 30 to 40 mm Hg within 1 min. This effect was dose dependent and the maximum effect was observed at a dose of 1.25 mg/kg. The prototype catecholamine norepinephrine induced a similar increase in blood pressure. When rats were pretreated with NG-monomethyl-L-arginine (L-NMMA, a blocker of nitric oxide) and challenged with cocaine, the increase in blood pressure was blocked by 80%, whereas pretreatment with L-NMMA did not block norepinephrine-induced vasoconstriction. Both cocaine and norepinephrine also induced an immediate vasoconstriction in isolated carotid artery preparations. The in vitro vasoconstriction induced by cocaine was blocked by pretreatment with L-NMMA, whereas L-NMMA did not block the norepinephrine-induced vasoconstriction in vitro. Furthermore, carotid artery stripped of endothelium responded to norepinephrine but failed to respond to L-NMMA or cocaine. S-nitroso-N-acetyl-D,L-penicillamine (SNAP)-a precursor of nitric oxide- stimulated nitric oxide production in control coronary artery fragments. When these fragments were incubated with cocaine there was a 20% reduction in the production of nitrite oxide. These results suggest that cocaine exerts its peripheral vasoconstriction at least in part by inhibiting local vasodilator nitric oxide.

Effect of glycated proteins on the matrix of glomerular epithelial cells

In this study, cultured glomerular epithelial cells (GEC) were exposed to a diabetic milieu containing glycated proteins to determine whether such proteins cause metabolic alterations that may lead to defects seen in the extracellular matrix in diabetic nephropathy. Cultured glomerular epithelial cells were cloned and maintained in RPMI media containing 10% fetal bovine serum (FBS). The medium was changed to RPMI-1% glycated FBS (experimental) or RPMI-1% control FBS, and cells were incubated for 1 or 4 d. Mitogenicity was tested by 3H-thymidine uptake. The media were collected and analyzed for collagenase activity by a quantitative fluorescence assay and by zymography. The cell layers were processed for matrix antigen (collagen I, glomerular basement membrane antigens, laminin, and fibronectin) and for the proteins of the tight junction (cadherin, desmosomal protein) by quantitative immunoperoxidase and immunofluorescence. Cell lysates were tested for cadherin and desmosomal protein by immunoblotting. Cells were also grown on 0.2-microM filter membranes to test for permeability to 3H-inulin and 125I-albumin. Glycated FBS resulted in a 1.8-fold increase in 3H-thymidine uptake in subconfluent layers accompanied by an increase in cell number. The treatment caused accumulation of laminin (18% above control, P < 0.05) and basement membrane antigens (33% above control, P < 0.05). Collagen I and fibronectin were unchanged. Exposing cells to glycated FBS changed the distribution of cadherin from a linear to a diffuse pattern associated with a decrease in cadherin observed on immunoblots. The media of glycated FBS-treated cells contained 45% lower collagenase activity (72-, 92-, and 150-kD species). Permeability to inulin increased by 550% and to albumin by 320% in glycated FBS-treated monolayers compared with controls. It is concluded that glycated proteins increased the accumulation of matrix proteins in the GEC, associated with a concomitant depression in collagenase activity. There were qualitative and quantitative changes in the tight junction protein cadherin. These matrix changes resulted in a functional defect in the permselective properties of the GEC tight junctions and manifested as increased leakage of inulin and albumin. Thus, the GEC are metabolically sensitive to the presence of glycated proteins, and this could play a role in the pathogenesis of diabetic nephropathy.

Accurate peptide sequencing by post-source decay matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Partial 18O-labeling of peptides has been applied to post-source decay experiments in a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. The ions which originate from the carboxyl terminus of a peptide partially retain 18O atoms which have readily been incorporated into the C-terminal carboxyl groups during enzymatic hydrolysis in a buffer containing 40 atom percent H218O. The isotopic resolution of singly charged precursor ions and their product ions obtained for peptides up to ca. 2800 Da has been achieved using the delayed extraction method, which permits the rapid identification and assignment of the 18O-labeled and non-labeled ion species in the PSD spectra. The results obtained from several 18O-labeled peptides, derived from an enzymatic digest, demonstrate the accuracy and reproducibility of the present method, which will be in widespread use for protein identification via database searching or for investigations of totally unknown proteins.

[The development of a microcomputerized fetal electrocardiograph]

A new microcomputerized Fetal Electrocardiograph (FECG) is presented in this paper. A two-grade configuration (front-end & back-end) is designed for the instrument. The front-end processor is based on a Digital Signal Processor (DSP) TMS32010 and the Adaptive Noise Cancelling (ANC) algorithm to extract FECG with non-invasive method. The processed results are sent to the back-end personal computer for real time display, analysis and record. Clinical tests show the instrument is designed smartly and operated easily, and can be applied widely to many medical situations.

[Influence of bitumen on burn wounds and their surrounding skin in guinea-pigs]

This study assessed the topical effects of bitumen on burn wounds and their surrounding skin in guinea-pigs. It consisted of three different experiments. The bitumen used in this experiment was a soft tar produced by Daye Steel Plant. The first experiment showed that the skin of the bitumen group marked pathological changes under both light and electron microscopes. The second experiment suggested that healing of the burn wounds of bitumen group was delayed, and less hair follicle counts and a lower intradermal thickness were found as compared with the other groups. The third experiment indicated that the wound edges had been seriously destroyed by bitumen, leading to enlargement of the size of the ulcers, and hypertrophy of scar occurred after healing. It is concluded that bitumen, especially the soft coal tar, has more errosive, irritating and destructive effects, therefore in bitumen burns the bitumen must be immediately and entirely removed from burn wounds.

Epiglottic laryngoplasty after hemilaryngectomy for glottic cancer

Epiglottic laryngoplasty is technically feasible as a one-stage procedure with excellent functional results. Although the Kambic-Sedlacek-Tucker (K-S-T) technique of glottic reconstruction offers early extubation with an adequate airway, a subsequent wide neoglottis may increase the chance of aspiration and a poor voice. To better restore the laryngeal functions of closure and phonation, we made some modifications on the original K-S-T technique as follows: (1) One of the lateral margins of the epiglottis with the aryepiglottic fold is sutured to the arytenoid region of the cricoid rather than a thyroid cartilage remnant. A neo-arytenoid is formed. (2) The other lateral margin of the epiglottis with the aryepiglottic fold is sutured to the cut edge of the false and true cord instead of a thyroid ala remnant. Therefore both margins of the epiglottis with the aryepiglottic folds are lowered as much as possible to the level of the glottis. A new pseudocord is formed. (3) A cartilage cut is made at the anterior aspect of the epiglottis, leaving its laryngeal surface of mucoperichondrial intact. A new anterior commissure with a sharp angle is shaped by this maneuver. Nineteen hemilaryngectomies with modified epiglottic laryngoplasty have been performed by members of the Department of Otolaryngology of Guangxi Medical College since 1984. Results in this series are fairly good and indicate that the modified epiglottic laryngoplasty is effective in enhancing functional results in terms of respiration, deglutition, and phonation.

Epiglottic laryngoplasty after extended hemilaryngectomy for glottic cancer

This paper reports the experience in the application of modified epiglottic laryngoplasty in 20 extended hemilaryngectomies for glottic carcinoma. The Kambic-Sedlacek-Tucker (K-S-T) technique using the epiglottis in glottic reconstruction can lead to early decannulation with an excellent airway, but a wide glottis formed after operation will increase the chance of aspiration and poor voice. Sphincteric function preservation of the glottis is a key point to success in partial laryngectomy. In order to prevent aspiration and to improve the quality of voice, the reconstructive technique as modified as follows: (1) Lateral margin of the epiglottis was sutured to the cricoid. (2) The superior edge of the epiglottis was lowered to reconstruct the ventricular band. (3) A cut was made at the anterior aspect of the epiglottis to reconstruct the anterior commissure. It is the experience of the authors that modified epiglottic laryngoplasty is better than the K-S-T technique for preservation of laryngeal function after extended hemilaryngectomy.