Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022672 (acute tubular necrosis)
 2,175 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three urinary lysosomal enzymes, beta-glucuronidase (beta-Gluc), beta-galactosidase (beta-Gal) and N-acetyl-beta-D-glucosaminidase (NAG), were measured in twenty-one renal allograft recipients to evaluate their role in the diagnosis and prediction of rejection episodes, and in the prediction of eventual graft outcome. A fluorometric assay using methylumbelliferone substrates was used to measure the three enzymes in morning urine samples and enzyme activity was defined in terms of urine creatinine concentration. Urinary NAG levels increased significantly in 13/16 first rejection episodes and 4/4 instances of acute tubular necrosis and graft infarction. In 5 of the 16 first rejection episodes the NAG was predictive of the rejection. NAG was not useful in diagnosing second or subsequent rejections and beta-Gluc and beta-Gal were of little value in assessing any component of renal transplant pathology. As a prognostic index of eventual graft outcome, the peak urinary NAG was particularly encouraging. It correlated strongly with deterioration in graft function as time passed such that only 2/10 patients with peak NAG greater than 1400 Units had normal serum creatinines at 6 months post transplantation. Conversely 4/4 patients with peak NAG levels less than 700 Units had normal serum creatinine at that time. In our series the measurement of urinary NAG was a useful adjunct to the diagnosis of first rejections but appears to be more valuable in predicting graft outcome.
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PMID:Urinary lysosomal enzyme excretion after renal allotransplantation. 10 10

Strong evidence suggests that replicative senescence is involved in vivo because senescent cells have been detected in human tissues associated with physiological and pathological aging processes. Chronic allograft nephropathy (CAN) appears to be a major determinant of long-term survival in kidney transplantation. Several mechanisms are potentially involved; the aim of this study was to assess the impact of replicative senescence in CAN. Replicative senescent cells were detected on renal tissue cryosection using expression of a specific marker, senescence-associated beta-galactosidase (SA-beta-Gal) at pH 6. A total of 80 frozen renal samples (67 cases of CAN and 13 controls) were studied. To validate this marker, we measured in situ telomere length in cells expressing or not expressing SA-beta-Gal using a validated quantitative fluorescence in situ hybridization technique. The presence of senescent cells was correlated with clinicopathologic data. Telomere length was significantly lower in cells expressing SA-beta-Gal than in cells that did not. Replicative senescence was present in 45 out of 67 (67%) biopsy specimens and was significantly associated with the severity of CAN. No correlation with the notion of a previous episode of acute tubular necrosis, acute rejection, extrarenal epuration, duration of cold ischemia, and the delay between transplantation and biopsy was observed. However, the age of the donor, but not that of the recipient, was correlated with the occurrence of senescent cells. These results suggest that replicative senescence is a mechanism that might be involved in the development of CAN. The age of the donor appears to be the major determinant factor in replicative senescence.
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PMID:The role of replicative senescence in chronic allograft nephropathy. 1456 89