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Biomedical subjects

M Sudo

Publications and source records attributed to M Sudo.

At least 271 records · Page 15Linked to original sources

Renal hemodynamics in oliguric and nonoliguric acute renal failure of rabbits.

The role of renal hemodynamic alterations in the curtailment of renal functions was studied in uranyl acetate-induced oliguric (ORF) and nonoliguric (NORF) renal failures of rabbits. 5 days after drug injection, renal functional and morphological changes were most remarkable. A depression of Cin and elevation of serum creatinine concentration were more marked in ORF than in NORF. Renal blood flow was high as compared to controls. Cortical blood flow redistributed to the inner cortex. There was no significant difference in renal blood flow or cortical flow distribution between renal failure models. The findings suggest the minor roles of renal blood flow and cortical flow distribution in maintaining renal failure in these nephrotoxic models. Prominent tubular necrosis was found in ORF but not in NORF. Arterial inulin concentration during retrograde ureteral infusion of 14C-inulin solution was significantly high in ORF as compared to controls and NORF. However, this inulin leakage was too small to explain severely curtailed inulin clearance.

Acute Kidney Injury↗

Identification of fatty acid methyl esters in kidneys and livers of two patients with Reye's syndrome.

An unusual lipid, having an Rf value between that of cholesterol ester and of triglyceride on thin-layer chromatography, was clearly demonstrated in lipids from kidneys and livers of two Japenese children with Reye's syndrome. Gas chromatography-mass spectrometry revealed that the unusual lipid from viscera of the patients was a mixture of fatty acid methyl esters. Whether the occurrence of fatty acid methyl ester is the result of an inborn error of metabolism common to both patients, who were the progeny of consanguineous marriages, or whether it is a common biochemical feature in Reye's syndrome remains the subject of future studies.

Chromatography, Gas↗

Studies on the CEA-like substance in gastric juice.

Concentration and heterogeneity of CEA-like substance in gastric juice were studied using radioimmunoassay. Statistically significant increase of CEA-like substance in gastric juice was found in advanced atrophic gastritis (P less than 0.01), early gastric cancer (P less than 0.05) and advanced gastric cancer (P less than 0.01) as compared with normal subjects. In cases with atrophic gastritis with a high degree of intestinal metaplasia, the concentrations above 300 microgram/dl were noticed. The results indicate that increased concentrations of CEA-like substance in gastric secretions may strongly suggest the presence of a marked intestinal metaplasia and/or cancerous changes of gastric mucosae, including the early cancer. The distribution of CEA activity in gel filtration fractions of gastric juice was compared using kits of two different radioimmunoassay systems. The patterns of CEA activities were different between the two different kits used, but the main peaks were located in the fractions with the molecular weight of 20x10(4) daltons corresponding to that of serum CEA. It is considered, however, that the CEA-like substance in gastric juice specimens may be more or less heterogenous when any of the methods is used.

Carcinoembryonic Antigen↗

Renal hemodynamics in uranyl acetate-induced acute renal failure of rabbits.

The role of renal hemodynamic alterations in the curtailment of renal function was studied in rabbits with uranyl acetate-induced acute renal failure. The day following the i.v. injection of uranyl acetate (2 mg/kg of body wt), renal blood flow (RBF) and clearance of creatinine (Ccr) decreased to approximately 60 and 20% of controls, respectively. Intracortical fractional flow distribution, estimated by radioactive microsphere method, did not change. The extraction ratio of para-aminohippurate (EPAH) decreased and the renal extraction of sodium (CNa/Ccr) increased, with minimal structural change in the kidney. Urine output increased to two to three times that of the control. After three days oliguria appeared despite complete recovery of RBF. The zonal flow redistributed toward the deep cortex. CCr and EPAH reached their minimums, concomitantly with tubular necrosis and intratubular casts. After seven days animals could be divided into the oliguric and diuretic groups. CCr and EPAH were higher in the diuretic group, while there was no significant difference in RBF and the flow distribution between groups. Regeneration of damagee tubular cells was found in the diuretic group but not in the oliguric group. The findings suggest the minor roles of RBF and the intracortical flow distribution, and a fundamental role of back leakage of filtrate across damaged tubular epithelium in the maintenance of reduced CCR and urine output during the oliguric stage in rabbits with uranyl acetate-induced renal failure.

Acute Kidney Injury↗

Analysis of estrogen glucuronides. I--Characterization of estrogen glucuronides by gas chromatography mass spectrometry.

The mass spectral characterization of nine kinds of estrogen glucuronides was investigated. The glucuronides were analysed after conversion to n-propyl ester-O-TMS ether derivatives by gas chromatography mass spectrometry. The fragmentation of these derivatives is discussed using deuterium labels and TMS-d9 imidazole. A clear-cut difference was found between aliphatic and aromatic glucuronic acid conjugates. In particular the [M - 362]+- fragment ion was characteristic in the mass spectra of estrogen 3-glucuronides. On the other hand, four isomers of estriol and 16-epiestriol glucuronides containing an aliphatic acetal linkage were also characterized by the fragment ions of m/e value 204, 345, 415, and 431 and their relative intensities. Thus, all nine estrogen glucuronides were discriminated mass spectrometrically.

Chemical Phenomena↗

Syntheses of estetrol monoglucuronides.

Four possible monoglucuronides of estetrol (estra-1,3,5(10)-triene-3,15 alpha, 16 alpha, 17 beta-tetraol) have been prepared from appropriately protected estetrol by the Koenigs-Knorr reaction employing cadmium carbonate as a catalyst. Condensation of methyl acetobromoglucuronate with estetrol 15,16,17-triacetate provided the 3-glucuronide acetate-methyl ester in a satisfactory yield. Introduction of the glucuronyl residue into C-17 was similarly attained by the use of estetrol 3-benzoate 15,16-acetonide. When estetrol 3,17-diacetate and acetobromosugar were stirred in anhydrous toluene in the presence of cadmium salt, the reaction occurred at C-16 and C-15 yielding two isomeric monoglucuronide derivatives in a ratio of ca. 5 to 2. Removal of the protecting groups in the four glucuronide acetate-methyl esters gave the desired estetrol glucuronides, respectively. These synthetic substrates underwent readily enzymatic hydrolysis with beef-liver beta-glucuronidase to afford estetrol.

Animals↗