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Biomedical subjects

K Matsui

Publications and source records attributed to K Matsui.

At least 757 records · Page 42Linked to original sources
PubMed1980

Predisposing factors of renal dysfunction following total correction of tetralogy of Fallot in the adult.

A retrospective study of 21 adult patients with tetralogy of Fallot (TOF) was undertaken to determine the predisposing risk factors of renal dysfunction following total correction of the disease. Five of the 21 patients exhibited moderate-to-severe postoperative azotemia and an additional five exhibited mild azotemia. Significant risk factors for postoperative renal dysfunction found in routine preoperative examinations were as follows: arterial oxygen saturation of less than 90%, cardiothoracic ratio (CTR) of greater than 50%, mean electrical axis of the QRS complexes of greater than +120 degrees, S wave in Lead V6 of greater than 7 mm, R/S voltage ratio in Lead V6 of less than 2, and negative T wave in Lead V6. In addition, preoperative cardiac catheterization data showed that the patients exhibiting postoperative azotemia had more severe pulmonary stenosis, a smaller pulmonary-to-systemic flow ratio (Qp/Qs), and a larger left ventricular cavity than nonazotemic patients. The incidence of postoperative low cardiac output state (LOS) was significantly higher in the azotemic patients. These findings suggest that a combination of the severe form of TOF and a large left ventricle increase susceptibility to LOS and postoperative renal dysfunction. The cause and the clinical significance of the large left ventricular cavity in adults with TOF are discussed.

Acute Kidney Injury↗
PubMed1980

A fluorinated glucose analog, 2-fluoro-2-deoxy-D-glucose (F-18): nontoxic tracer for rapid tumor detection.

Rapid uptake of F-18 FDG was observed in a variety of transplanted and spontaneous tumors in animals. The tumor uptake reached a peak by 30 min and remained relatively constant up to 60 min, with a very slow wash-out of F-18 activity from the tumor thereafter. Tumor-to-normal tissue and tumor-to-blood ratios ranged from 2.10-9.15 and 2.61-17.82, respectively, depending on the type of tumor. A scintiscan of a seminoma in a dog showed very high uptake in the viable part and lack of uptake in the necrotic mass. Toxicological studies in mice using 1000 times human tracer dose (HTD) per wk for 3 wk and in dogs using 50 times HTD per wk for 3 wk did not show any evidence of acute or chronic toxicity.

Abscess↗
PubMed1979

Spectroscopic studies of pyridoxamine (pyridoxine) 5'-phosphate oxidase. Equilibrium dissociation constants and spectra for riboflavin 5'-phosphate and analogues.

Pyridoxamine (pyridoxine) 5'-phosphate oxidase (EC 1.4.3.5) has been shown to bind 1 mol of riboflavin 5'-phosphate (FMN) per mol of apoenzyme and is active with or inhibited by numerous FMN analogues [Kazarinoff, M. N., & McCormick, D. B. (1975) J. Biol. Chem. 250, 3436--3442]. The KD values and spectra for selected apoenzyme--flavin complexes have been determined and used to elucidate some of the properties of the FMN-binding site of this flavoprotein. Alterations of the pyrimidinoid portion of the flavin ring decrease binding considerably. The absorption spectra for the protein complexes with 3-deaza-FMN and 8-hydroxy-FMN indicate the presence of a dipolar or positively charged protein group near N1 and O2. The substitution of methyl for hydrogen at N3 apparently causes distortion of the interaction between the flavin ring and an active-site aromatic amino acid residue. Although binding is also decreased somewhat by substitutions at postions 8 and 8 alpha, considerable bulk [e.g., 8-(diethylamino)-FMN and 8 alpha-S-(N-acetyl-cysteinyl)-FMN] is accommodated. Hence, this portion of the flavin ring is probably oriented toward, possibly in contact with, solvent, as has been found for the flavodoxins. The importance of optimum interactions between the flavin and the apoprotein is further emphasized by large differences in the activity of flavin analogues that have similar midpoint potentials in solution.

Apoenzymes↗
PubMed1979

Effects of dietary cadmium on rhesus monkeys.

Ten male rhesus monkeys, each weighing 3.5 kg, were divided into four groups of 3, 3, 2, and 2, and were fed daily with 100 g pelleted food containing 300, 30, 3, and 0 ppm cadmium, respectively. Urine samples were collected every 2 weeks and blood samples every 4 weeks. One monkey each of the 300 and 30 ppm groups was autopsied for pathological examination and tissue cadmium determination at the week 24 of the experiment; the remaining 8 animals were killed after 55 weeks. The lowest exposed group (3 ppm) did not show any specific biological response to cadmium over a period of 55 weeks. In the 30 ppm group, no significant changes were observed for up to 24 weeks, although cadmium concentration in the renal cortex and urine at 24 weeks were 300 mug/g wet weight and 18 mug/l., respectively. Plasma urea nitrogen and urine protein (quantitative determination) increased after 30 and 36 weeks. At 55 weeks of the experiment, qualitative tests were negative for low molecular weight proteinuria and glycosuria, and the results remained normal for renal and liver function tests and blood analysis, although cadmium concentrations in the renal cortex of two monkeys were 460 and 730 mug/g wet weight and those in the liver were 110 and 160 mug/g wet weight, respectively. In the highest exposure group (300 ppm), urine cadmium increased to 250 mug/l. by 11 weeks, and urine retinol-binding protein, plasma GOT, GPT, and LDH increased after 12 weeks. Proteinuria (quantitative determination), glycosuria, aminoaciduria (panaminoaciduria), and erythrocytopenia were observed after 16 weeks, when urine cadmium was 500-900 mug/l. Hypohemoglobinopathy and proteinuria (qualitative determination) were observed after 20 and 24 weeks, while cadmium concentrations in the renal cortex and the liver were 760 and 430 mug/g wet weight at 24 weeks, respectively. Slightly depressed tubular reabsorption of phosphate, increased urine beta(2)-microglobulin, increased plasma urea nitrogen, and increased plasma alpha(2)-globulin fraction (electrophoresis) were observed between 28 and 30 weeks of the experiment. Creatinine clearance and plasma cholinesterase decreased after 47 and 54 weeks, respectively. Cadmium concentrations in the renal cortex and the liver of two monkeys at 55 weeks were 350 and 580 mug/g wet weight and 410 and 630 mug/g wet weight, respectively. Pathological examinations revealed denaturation, destruction, and regeneration of the epithelial cells in renal proximal tubules, but no pathological changes in osseous tissues. Critical cadmium concentration in the renal cortex was estimated to be 380 mug/g wet weight for low molecular weight proteinuria and 470 mug/g wet weight for proteinuria, glycosuria, and aminoaciduria. Critical concentration in the liver was also estimated to be 210 mug/g wet weight. The apparent biological half-time of cadmium in monkeys at autopsied stage was calculated to be 0.66, 6.4, 5.2, and 22.4 years for the 300, 30, 3, and 0 ppm groups, respectively.

Animals↗
PubMed1979

Hypothalamic hypernatremia due to volume--dependent ADH release, and its treatment with carbamazepine and clofibrate.

A 23-year-old man, diagnosed as having a pituitary adenoma at the age of 17 and received an operation 1 month ago showed a fluctuating hypernatremia and hypodipsia. The water deprivation, water load and hypertonic saline infusion tests were carried out. After a 14-hr water deprivation test, plasma osmolality was 310 mOsm/kg, plasma ADH was 1.5 microunits/ml, and urine osmolality was 591 mOsm/kg. On the water load test subsequently performed, the plasma osmolality decreased to 297 mOsm/kg, but the urine was still hypertonic. Infusion of 2.5% saline solution elicited paradoxically a marked diuresis and dilution of urine despite the elevàtion of plasma osmolality. On the treatment with carbamazepine and clofibrate, the urinary osmolality increased, the hypernatremia was normalized, and a marked natriuresis was elicited with a gain in body weight. These results suggested that the secretion of ADH is regulated by changes in blood volume rather than by the plasma osmolality in this patient. The hypernatremia may be explained as a disturbance or lack of osmoreceptor function for ADH release and the loss of thirst sensation, though the volume receptor still remains functioning for ADH secretion. Depletion of the extracellular fluid volume may be another contributing factor to the elevation of serum sodium level by enhancing the reabsorption of sodium from renal tubules.

Adult↗
PubMed1979

Anti-riboflavin activity of 8-O-alkyl derivatives of riboflavin in some Gram-positive bacteria.

Two new 8-O-alkyl derivatives of riboflavin (RF), i.e., 8-methoxy- (MOF), and 8-ethoxy-8-demethyl-D-riboflavin (EOF), their tetraacetate, and the tetraacetate of 8-hydroxy-8-demethyl-D-riboflavin (HOF) were synthesized. The anti-RF activity of MOF, EOF and HOF was estimated from the ratio CR/CI, where CI is the concentration of test flavin added to the culture medium and CR is the minimum concentration of RF needed to restore the growth inhibition. Their activity was also compared with that of roseoflavin (RoF). The decreasing order of anti-RF activity was as follows: MOF greater than RoF greater than EOF in Sarcina lutea: RoF greater than MOF greater than EOF in Bacillus cereus and Staphylococcus aureus. HOF showed no activity in any of the bacteria tested. The redox potential of these compounds decreases as follows: RF greater than RoF greater than EOF greater than MOF greater than HOF, and the RF activity of MOF and EOF could be explained by the redox potential difference between these compounds and RF.

Bacillus cereus↗