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M Ryska

Publications and source records attributed to M Ryska.

45 records · Page 3Linked to original sources
PubMed1984

Determination of metabolites of 3-chloro-4-benzyloxyphenylacetic acid (benzofenac) by GC/MS method.

Metabolites of benzofenac (3-chloro-4- benzyloxyphenylacetic acid) were determined in rat, rabbit, dog, and human urine by GC/MS. Before analysis the urine was extracted and the extracts were treated with diazomethane. Deuterium-labelled benzofenac , 3-chloro-4-[( methylene-2H2]- benzolyoxy ) phenylacetic acid was used for the elucidation of the structures of some main metabolites and the determination of trace metabolites. The structures of the metabolites were determined from spectra obtained by electron impact and chemical ionization.

Animals↗
PubMedDate not supplied

Devascularization surgical model of acute liver failure in minipigs.

AIM: The study was designed to develop a readily reproducible model of acute liver failure (ALF) in the minipig, to gain an 8-hour therapeutic window to mimic, as closely as possible, acute liver failure in man. METHOD: We used reversible devascularization model of ALF in the minipig involving hepatic artery ligation and establish an end-to-side portocaval anastomosis. Standard laboratory monitoring was complemented with intracranial pressure (ICP) measurement. MATERIAL: Twenty minipigs (weight 25-30 kg) were used for the experiment. The animals were divided into 3 groups: I: 10 animals in an experimental group with ALF; II: 5 animals in an experimental group with ALF and ICP measurement, and III: 5 animals in a control group without ALF. RESULTS: Laboratory testing has shown the significant changes in levels of AST (33.44 +/- 39.96 vs. 1.56 +/- 0.50 mmol/l), lactate (2.97 +/- 1.16 vs. 1.18 +/- 0.61 mmol/l), and ammonia (264.3 +/- 93.05 vs. 42.5 +/- 12.98 mmol/l) between ALF groups and controls (p < 001) 6 h after the operative procedure, and significant changes in hypoglycemia and intracranial pressure were found 4 h after the operative procedure. The difference in Quick values (67.4 +/- 17.03 vs. 75.2 +/- 2.68) was not significant. We assume that the therapeutic window starts 4 h after the beginning of the experiment. CONCLUSION: Our devascularization model of ALF is simple and readily reproducible. The therapeutic window occurring shortly after surgery and persisting for a mean 9 h is suitable to evaluate bioartificial liver devices.

Animals↗
PubMedDate not supplied

Preservation injury of jejunal grafts and its modulation by custodiol and university of wisconsin perfusion solutions in wistar rats.

BACKGROUND: The two preservation solutions most commonly used in human transplantation surgery are University of Wisconsin (UW) and Custodiol (histidine-tryptophan-ketoglutarate; HTK). The aim of our study was to compare the protective effect of UW and HTK solutions on preservation-induced injury of jejunal grafts, as evaluated by the histological changes (semiquantitative method) and small bowel mucosal serotonin levels (as a possible new quantitative method). METHODS: Male Wistar rats (n = 50) weighing 316 +/- 52 g were divided into two main groups according to which preservation solution was used, i.e. UW (n = 25) or HTK (n = 25), and each of these groups was divided into five subgroups according to cold ischemic time (0, 1, 6, 9 and 12 h). Jejunal mucosa biopsy specimens were obtained to determine the serotonin concentration in mucosa and for standard light histology. To grade histological changes in mucosa, Park's small bowel injury grading system was used. RESULTS: Histological examination revealed that injury increased with cold ischemic time in the UW as well as in the HTK group, and there were no significant differences in injury between the two groups, except for the 6-hour cold ischemic period (p < 0.05), when HTK-preserved grafts showed a lower degree of injury (0.97 +/- 0.41) compared with UW-preserved grafts (1.25 +/- 0.39). The mucosal serotonin concentration decreased with cold ischemic time in both groups, and there were significant differences (p < 0.05) in concentrations between the groups after 9 and 12 h of cold ischemia. A significantly higher concentration was measured in grafts preserved in UW solution at these time points. CONCLUSION: The concentration of mucosal serotonin in rat small bowel grafts preserved for 9 and 12 h in UW preservation solution was significantly higher than that in HTK solution. These findings indicate a better protective effect of UW solution on small bowel injury after 9 h of cold ischemia.

Adenosine↗