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Biomedical subjects

D Serur

Publications and source records attributed to D Serur.

At least 19 recordsLinked to original sources
PubMed2001

Noninvasive diagnosis of renal-allograft rejection by measurement of messenger RNA for perforin and granzyme B in urine.

BACKGROUND: Acute rejection is a serious and frequent complication of renal transplantation, and its diagnosis is contingent on the invasive procedure of allograft biopsy. A noninvasive diagnostic test for rejection could improve the outcome of transplantation. METHODS: We obtained 24 urine specimens from 22 renal-allograft recipients with a biopsy-confirmed episode of acute rejection and 127 samples from 63 recipients without evidence of acute rejection. RNA was isolated from the urinary cells. Messenger RNA (mRNA) encoding the cytotoxic proteins perforin and granzyme B and a constitutively expressed cyclophilin B gene were measured with the use of a competitive, quantitative polymerase chain reaction, and the level of expression was correlated with allograft status. RESULTS: The log-transformed mean (+/-SE) levels of perforin mRNA and granzyme B mRNA, which encode cytotoxic proteins, but not the levels of constitutively expressed cyclophiiin B mRNA, were higher in the urinary cells from the 22 patients with a biopsy-confirmed episode of acute rejection than in the 63 recipients without an episode of acute rejection (perforin, 1.4+/-0.3 vs. -0.6+/-0.2 fg per microgram of total RNA; P<0.001; and granzyme B, 1.2+/-0.3 vs. -0.9+/-0.2 fg per microgram of total RNA; P<0.001). Analysis involving the receiver-operating-characteristic curve demonstrated that acute rejection can be predicted with a sensitivity of 83 percent and a specificity of 83 percent with the use of a cutoff value of 0.9 fg of perforin mRNA per microgram of total RNA, and with a sensitivity of 79 percent and a specificity of 77 percent with the use of a cutoff value of 0.4 fg of granzyme B mRNA per microgram of total RNA. Sequential urine samples were obtained from 37 patients during the first nine days after transplantation; and measurements of the levels of mRNA that encoded cytotoxic proteins identified those in whom acute rejection developed. CONCLUSIONS: Measurement of mRNA encoding cytotoxic proteins in urinary cells offers a noninvasive means of diagnosing acute rejection of renal allografts.

Acute Disease↗
PubMed2001

Renin system activation and delayed function of the renal transplant.

Delayed graft function (DGF), defined as persistent renal failure that requires dialysis within the first week after kidney transplantation, occurs commonly after cadaveric renal transplantation (CRT). This has important implications for long-term outcome because the 1-year allograft survival rate is significantly reduced when DGF occurs. The mechanisms contributing to the development of DGF are not well established. However, several lines of evidence indicate that excess renin system activity, in both the cadaver kidney donor and recipient, contributes importantly to the pathogenesis of DGF. If this hypothesis can be verified in clinical studies, then pharmacologic agents that interrupt the renin-angiotensin system (eg, type 1 angiotensin II receptor blockade, angiotensin converting enzyme inhibition, and beta-adrenergic blockade) in the donor and recipient might significantly improve the outcome of cadaveric renal transplants.

Graft Survival↗
PubMed1999

Heterogeneously vancomycin-resistant Staphylococcus epidermidis strain causing recurrent peritonitis in a dialysis patient during vancomycin therapy.

Methicillin-resistant Staphylococcus epidermidis (MRSE) was recovered over a 2-month period from the dialysis fluid of a peritoneal dialysis (PD) patient who experienced recurrent episodes of peritonitis during therapeutic and prophylactic use of vancomycin. Characterization of five consecutive MRSE isolates by molecular and microbiological methods showed that they were representatives of a single strain, had reduced susceptibility to vancomycin, did not react with DNA probes specific for the enterococcal vanA or vanB gene, and showed characteristics reminiscent of the properties of a recently described vancomycin-resistant laboratory mutant of Staphylococcus aureus. Cultures of these MRSE isolates were heterogeneous: they contained-with a frequency of 10(-4) to 10(-5)-bacteria for which vancomycin MICs were high (25 to 50 microg/ml) which could easily be selected to "take over" the cultures by using vancomycin selection in the laboratory. In contrast, the five consecutive MRSE isolates recovered from the PD patient during virtually continuous vancomycin therapy showed no indication for a similar enrichment of more resistant subpopulations, suggesting the existence of an "occult" infection site in the patient (presumably at the catheter exit site) which was not accessible to the antibiotic.

Adult↗
PubMed1998

Interleukin-6 predicts hypoalbuminemia, hypocholesterolemia, and mortality in hemodialysis patients.

Low serum albumin and low serum cholesterol levels are among the most consistent predictors of mortality in patients with end-stage renal disease (ESRD) undergoing hemodialysis. Hypoalbuminemia is often interpreted as a marker of poor nutrition, but serum albumin and cholesterol levels can also be low as part of a cytokine-mediated acute-phase reaction to acute or chronic inflammation. Here we report the results from a 900-day prospective study designed to determine whether tumor necrosis factor-alfa (TNF-alpha) and interleukin-6 (IL-6) predict serum albumin and cholesterol levels and mortality in a group of 90 ambulatory, adult hemodialysis patients with no acute infection, hospitalization or surgery, and no known acquired immunodeficiency syndrome (AIDS), malignancy, or liver disease. Measurable levels of TNF-alpha and/or IL-6 were found in 89 of 90 patients. Significant relationships were found between TNF-alpha and IL-6 and the degree of hypoalbuminemia and dyslipoproteinemia. IL-6 was the strongest predictor of mortality in univariate and multivariate analysis, followed by age, albumin level, and body mass index (BMI). Although the cause of hypercytokinemia was not addressed in this study, the data support the view that hypoalbuminemia and hypocholesterolemia are negative acute-phase responses to inflammatory stimuli. These results suggest that efforts to identify the nature of the stimuli for cytokine production and to lower cytokine levels in hemodialysis patients might be effective in improving the survival of patients undergoing hemodialysis.

Adolescent↗
PubMed1997

Effect of nifedipine on renal allograft function and survival beyond one year.

We previously reported that a calcium channel blocker supplemented immunosuppression produced excellent patient and graft survival rates in cadaveric kidney transplantation. We report here the long term outcome of patients treated with nifedipine-supplemented triple immunosuppression as compared with those of historical controls who were treated similarly without nifedipine. Study subjects included 111 patients transplanted in 1990-1994, treated with nifedipine and triple immunosuppression and with functioning grafts for more than one year (Nifedipine group). The results of cyclosporine (CyA) dose, blood pressure (BP), serum creatinine (Cr), and actuarial graft survival rate (GSR) up to 5 years posttransplant in these patients were compared with those of 52 patients transplanted in 1985-1990, treated similarly without calcium channel blockers (Control group). Donor sources, gender ratio, age distribution, causes of end stage renal disease, incidence of hypertension prior to transplantation and incidence of rejection in the first year between the groups were comparable. Throughout the study period the Nifedipine group had significantly lower serum Cr (1.5 +/- 0.7 vs. 1.8 +/- 0.7 mg/dl) and higher GSR (93.8% vs. 88% at 5 years) than the Control group. BP was comparable despite higher CyA doses in the Nifedipine group (4.3 +/- 1.1 vs. 3.3 +/- 1.1 mg/kg/day). We conclude that nifedipine is beneficial in improving long-term graft function and survival in kidney transplant recipients by mitigating CyA associated renal injury.

Adult↗
PubMed1996

Molecular executors of cell death--differential intrarenal expression of Fas ligand, Fas, granzyme B, and perforin during acute and/or chronic rejection of human renal allografts.

Two distinct cytolytic pathways have been characterized: one in which the interaction between the Fas antigen and its ligand results in apoptosis, and another in which the pore forming protein perforin and the serine protease granzyme B contribute to DNA fragmentation and cell death. We investigated intrarenal expression of these molecular executors of cell death in light of the potential participation of cytolytically active cellular elements in the antiallograft repertory. Reverse transcriptase-polymerase chain reaction was used to identify intrarenal expression of Fas antigen, Fas ligand, granzyme B and perforin in eighty human renal allograft biopsies; mRNA display was correlated with the Banff histological diagnosis of renal allografts. Our studies demonstrate that: (1) intrarenal expression of Fas ligand mRNA and of granzyme B mRNA are correlates of acute but not chronic rejection; (2) Fas ligand mRNA is not detectable in allografts in the absence of rejection; (3) intrarenal coexpression of members of each lytic pathway (Fas ligand and Fas, granzyme B, and perforin) and that of both pathways (e.g., Fas ligand and granzyme B) are correlates of acute rejection; and (4) a direct correlation exists between the histological severity of acute rejection and intrarenal coexpression of mRNA encoding Fas ligand, Fas, granzyme B, and perforin. Our studies identify, for the first time, the differential expression of the two major lytic pathways in acute and chronic allograft rejection and suggest that specific therapy directed at the cytotoxic attack molecules might be efficacious in the prevention and/or treatment of acute rejection.

Acute Disease↗
PubMed1996

Intragraft TGF-beta 1 mRNA: a correlate of interstitial fibrosis and chronic allograft nephropathy.

Chronic allograft nephropathy is a relentlessly progressive process and a major cause of long-term graft dysfunction and ultimate failure. Interstitial fibrosis, tubular atrophy, and glomerular and vascular lesions characterize this mechanistically unresolved disorder. Given the prominent role of TGF-beta 1 in tissue repair and in fibrosis, we have explored the hypothesis that fibrosis and chronic allograft nephropathy would be distinguished by intragraft TGF-beta 1 mRNA expression. This postulate was tested by mRNA phenotyping of RNA isolated from 127 human renal allograft biopsies. Reverse transcription assisted polymerase chain reaction was used to amplify and identify ingraft gene expression. Our investigation demonstrated a significant correlation between intragraft TGF-beta 1 mRNA display and renal allograft interstitial fibrosis and chronic allograft nephropathy. In contrast, intragraft expression of mRNA encoding immunoregulatory cytokines, IL-2, IFN-gamma, IL-4, IL-10, or cytotoxic attack molecules, granzyme B and perforin was not a correlate of interstitial fibrosis or chronic allograft nephropathy. Our studies identify, for the first time, a significant association between intragraft TGF-beta 1 mRNA expression and renal allograft interstitial fibrosis, and advance a candidate molecular mechanism for chronic allograft nephropathy.

Base Sequence↗
PubMed1995

Intragraft expression of IL-10 messenger RNA: a novel correlate of renal allograft rejection.

A major conceptual advance is the formulation that type I cytokines (such as IL-2 and IFN-gamma) enhance cellular immunity and are host-protective, and that type II cytokines (such as IL-4 and IL-10) dampen cellular immunity and facilitate the progression of infection. We have explored the intragraft expression of type I and type II cytokines during human renal allograft rejection. RNA was isolated from 98 allograft biopsies, and reverse transcription-PCR was used to amplify and identify intragraft expression of mRNA encoding IL-2, IFN-gamma, IL-4, or IL-10. Intragraft expression of IL-7 mRNA and TGF-beta 1 mRNA was also investigated. Our investigation demonstrated that: (a) intragraft expression of IL-10 mRNA and IL-2 mRNA are significant correlates of acute rejection; (b) IL-4, IL-7, IFN-gamma and TGF-beta 1 mRNA expression do not correlate with acute rejection; and (c) IL-10 does not prevent in vivo expression of IFN-gamma, IL-2, IL-7, or TGF-beta 1. Our studies identify, for the first time, a significant association between intragraft IL-10 mRNA expression and acute rejection, and suggest that treatment strategies capable of constraining IL-10 expression might be of value in the prevention of acute rejection.

Base Sequence↗
PubMed1994

How well is hypertension controlled in CAPD patients?

UNLABELLED: To determine how well hypertension is controlled in continuous ambulatory peritoneal dialysis (CAPD) patients, we monitored the blood pressure of 31 hypertensive adult CAPD patients treated with antihypertensive agents. Blood pressure (BP) monitoring, using a noninvasive, ambulatory BP monitor, began in the morning and continued every 30-60 min for 24 h (mean 42 readings per patient). The mean BP of all patients over 24 h was 145.6/91.3 mm Hg. In these, 40.5% of systolic BP readings exceeded 150 mm Hg and 50.2% of diastolic readings exceeded 90 mm Hg, suggesting that hypertension was inadequately controlled for a considerable period of time. Diabetic patients had even worse control of BP. Mean BP, heart rates, and BP loads were not different, between daytime or nighttime. These findings suggest that CAPD patients do not preserve the normal circadian rhythm of BP and that their hypertension is not controlled any better during the night than during the day. We repeated BP monitoring after adjustment of antihypertensive medications in 8 patients who had poorly controlled hypertension. Systolic and diastolic BP loads in subsequent studies improved significantly from the first study. IN CONCLUSION: hypertension is suboptimally controlled in most CAPD patients; diabetic patients fare even worse in the control of hypertension; most patients do not preserve the circadian rhythm of BP and there is no difference in the adequacy of hypertension control during the day or at night; assessment of hypertension with ambulatory BP monitoring helps guide therapy and control of hypertension.

Adult↗
PubMed1988

Agenesis of the corpus callosum: clinical, neuroradiological and cytogenetic studies.

This study examined 35 patients with developmental disabilities who were referred for diagnostic evaluation that later revealed agenesis of the corpus callosum (ACC) by computerized tomography (CT). Sixteen had partial ACC, six had complete ACC, and one had a hypoplastic corpus callosum. In the other twelve cases, ACC existed, but the degree of callosal defect was not specified. Other intracranial defects were frequently present. Clinically, 15 patients (43%) had a history of seizures, 28 (82%) were mentally retarded or developmentally delayed and an additional five patients (15%) possessed borderline intelligence, and 10 (29%) had cerebral palsy. Ocular, spinal, and orofacial abnormalities were often present. Detailed summaries of these findings are given in Table I. Although several genetic causes of ACC have been identified, in the vast majority, the etiology is assumed to be multifactorial. In our study, two patients had trisomy 8 mosaicism and 11 (35%) had a family history of developmental disability. A review of the literature on chromosomal abnormalities in acalossal patients revealed 81 additional cases, which are discussed and outlined in Table II.

Adolescent↗
PubMed1987

Clinicopathological findings associated with agenesis of the corpus callosum.

Seven hundred five cases of agenesis of the corpus callosum (ACC) are reviewed from the literature (n = 660) and from our own observations (n = 45). The diagnosis was made or confirmed using neuroradiological techniques (n = 519) and necropsy or surgery (n = 231). Association with abnormalities often of chromosomes 8, 11, 13-15 and 18 suggests their involvement in abnormal corpus callosum (CC) morphogenesis. Four syndromes (e.g. Aicardi, acrocallosal, Andermann and Shapiro) are characterized by ACC, while others are only sporadically associated (e.g. fetal alcohol syndrome, Dandy-Walker syndrome, Leigh disease, Arnold-Chiari II syndrome). In non-Aicardi patients, the male-to-female ratio was 3:2 and X-linked recessive inheritance is postulated to play a role in some cases. Common abnormalities in acallosal patients included: mental retardation (MR), 73% [corrected]; seizures, 42%; ocular anomalies, 42%; gyral abnormalities, 32%; hydrocephalus, 23%; other central nervous system (CNS) lesions, 29%; costovertebral defects, 24%. Developmental disabilities are not attributable to absence of the CC per se, but due to other CNS malformation or dysfunction, which may be genetic or non-genetic. Future research using recombinant DNA techniques will enable isolation and identification of specific chromosomal defects in those cases with a genetic abnormality.

Abnormalities, Multiple↗