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)

A group of 40 cadaveric kidneys was studied just prior to planned transplantation to further assess the applicability of 31P-MRS in the analysis of clinical renal transplant viability. Renal intracellular high-energy phosphorus metabolites (ATP [or NADP], phosphomonoester [PME] and inorganic phosphate [Pi]) and pH were measured noninvasively with MRS surface coils external to cold storage containers. Pretransplant MRS parameters were correlated with subsequent renal function in recipient patients (measured one week postoperatively by the need of dialysis, drop in serum creatinine, urine output, and 123I or 131I Hippuran assessed renal tubular function). ATP and NADP was detected in eleven kidneys and was significantly (P less than 0.001) associated with the best renal function posttransplantation. These kidneys also had the highest PME/Pi ratios (1.66-0.54), while lower ratios (0.36-0.10) were associated with prolonged acute tubular necrosis. The PME/Pi ratios significantly (P less than 0.0001) correlated with subsequent clinical renal function, whereas cold storage times (37 +/- 10 hr) or intracellular renal pH (6.53-7.91) did not. These preliminary data suggest that MRS is a noninvasive, nondestructive and sterile method for assessing clinical viability during hypothermic storage of human cadaver kidneys and the subsequent recovery of renal function postrenal transplantation.
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PMID:Pretransplant assessment of renal viability by phosphorus-31 magnetic resonance spectroscopy. Clinical experience in 40 recipient patients. 266 35

As acute tubular necrosis (ATN) is still an important cause for postoperative malfunction of renal grafts, it would be useful to have a method predicting such a complication. We investigated the possibility to predict ATN by measuring the ratio of phosphomonoesters (PME, largely consisting of adenosine monophosphate) and inorganic phosphate (Pi) in the renal tissue, using 31P magnetic resonance spectroscopy (MRS) during the cold ischemia period. Assuming that this ratio reflects the tissue high-energy phosphate status, we studied five kidneys from living related donors (LRD), 28 kidneys from heart beating donors (HBD) and nine kidneys from non-heart beating donors (non-HBD). All kidneys were preserved with a phosphate free solution. We found an inverse relation between the time of 31P MRS and the PME/Pi ratio, suggesting a graded decay of tissue high energy phosphates during cold ischemia. The PME/Pi ratio was highest in grafts from LRD (2.65 +/- 0.50, no ATN), intermediate in grafts from HBD (1.65 +/- 0.41, 21% ATN) and lowest in those derived from non-HBD (1.05 +/- 0.47, 56% ATN). The differences in PME/Pi ratio between the groups was statistically significant (P < 0.01). Moreover, the ratio was significantly lower in grafts developing ATN (1.73 +/- 0.41 vs. 1.35 +/- 0.29 in the HBD group, 1.41 +/- 0.24 vs. 0.76 +/- 0.36 in the non-HBD group, P < 0.05). These observations point to a general relation between the pre-transplant kidney PME/Pi ratio and the development of ATN. However, the predictive value of a low PME/Pi ratio was too low (36%) to reliably predict development of ATN in individual cases.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pre-transplantation assessment of renal viability with 31P magnetic resonance spectroscopy. 770 29

Volume-selective 31P-MR spectra were obtained from 37 patients using a whole-body MR scanner in combination with surface coils and a modified ISIS sequence. The quantitative evaluation took place by line fitting to the signal in the time domain using a non-linear procedure. The following signal intensities were determined: PME, PDE, Pi, gamma-, alpha-, beta-ATP and pH. 1024 excitations were averaged to achieve an adequate signal-to-noise ratio (10.0 +/- 3.3), measurements lasting 34 minutes on average. The mean measured volume was 174 +/- 52.4 ml. Contamination by muscle tissue could be excluded based on the absence of phosphocreatinine signal in the spectra. Contamination by fatty tissue was excluded by visualisation. A reduction in the value of the Pi/alpha-ATP ratio as a function of time was observed due to the regeneration process following reperfusion injury. In transplant rejection (n = 7) a significant rise in Pi/alpha-ATP ratio was seen compared to the control group (n = 20) (0.4 +/- 0.16 vs. 0.22 +/- 0.11, p < 0.01), the calculated difference in pH was significant as well. In cases of acute tubular necrosis a reduced value fore the PME/PDE ratio was observed (0.65 +/- 0.1 vs. 0.96 +/- 0.5, p < 0.04). Acute tubular necrosis could be differentiated from rejection by difference in pH (6.93 +/- 0.1 vs. 7.14 +/- 0.19, p < 0.04).
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PMID:[Volume selective 31P NMR spectroscopy for differentiation of graph rejection and acute tubular necrosis after kidney transplantation]. 1451 32