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Biomedical subjects

K Matsui

Publications and source records attributed to K Matsui.

At least 19 recordsLinked to original sources

Mitomycin C, vindesine, and cisplatin in advanced non-small-cell lung cancer. A phase II study.

Between August 1985 and June 1986, 49 previously untreated patients with locally advanced or metastatic non-small-cell lung cancer (NSCLC) were treated with the combination of cisplatin 80 mg/m2 i.v. on day 1, vindesine 3 mg/m2 i.v. on days 1 and 8, and mitomycin-C 8 mg/m2 i.v. on day 1 (MVP), repeating after an interval of 4 weeks, and thereafter every 6 weeks. The median age for all patients was 62 years, with a range of 21 to 77 years. All patients had a performance status of 0, 1, or 2 (ECOG scale) and measurable disease. Histologic types included squamous cell carcinoma (22 patients), adenocarcinoma (22 patients), and large-cell carcinoma (6 patients). Forty-eight patients were evaluable for response. Out of 48 patients, one (2%) achieved a complete response and 24 patients (50%) achieved a partial response, resulting in an overall response rate of 52% (95% confidence interval, 38-68%). The response rates were 52% for squamous cell carcinoma, 45% for adenocarcinoma, and 80% for large-cell carcinoma, respectively. The median duration of response was 4.2 months and the median duration of survival for all patients was 10.6 months. The major toxicity was myelosuppression. Leukopenia and thrombocytopenia of grade 3 or 4 occurred in 85% and 33%, respectively. One patient died of sepsis associated with leukopenia. Other toxicities were manageable and reversible. In conclusion, the MVP regimen was active and tolerable in patients with advanced NSCLC. Prospective randomized study comparing the MVP regimen with the two-drug combination of vindesine and cisplatin is warranted.

Adult

Partial seizures in two cases of metachromatic leukodystrophy: electrophysiologic and neuroradiologic findings.

This report concerns two cases of metachromatic leukodystrophy presenting partial seizures. One was a 2-year-old boy with a late infantile type and the other a 17-year-old girl with a juvenile type. The former had tonic-clonic seizures on the left with concomitant twitching of the left side of the face and adversive conjugate deviation of the eyes. After a while, his interictal sleep electroencephalogram (EEG) showed spikes in the right central area. The second case had hemiconvulsions on the right side, consisting mainly of tonic flexion of the upper limb followed by clonic flexions, and accompanied by adversive conjugate deviation of the head and eyes. Her ictal EEG showed rhythmic 6- to 7-Hz wave bursts in the left frontal area. To this date, no report has given a detailed discussion of the type of seizures and ictal EEG in metachromatic leukodystrophy. In addition, there have been few detailed reports of magnetic resonance imaging (MRI) in the juvenile type. It is interesting that typical partial seizures were observed in a hereditary metabolic disorder characterized by diffuse demyelination of the white matter, and the pathophysiology is discussed here mainly in relation to MRI findings of the case with the juvenile type.

Adolescent

[Prostate cancer after subcapsular prostatectomy diagnosed as benign prostate hypertrophy--clinico-pathological analysis].

Of 160 newly diagnosed cases of prostate cancer during last 11 years, six (3.75%) had a prior subcapsular prostatectomy. Digital rectal examination in these six cases revealed a significant prostatic abnormality and multiple bone metastases were showed. Histological examination by step-section technique was done retrospectively using surgical materials from subcapsular prostatectomy. Two cases of incidental carcinoma were detected histologically. One showed stage A1 and another stage A2. Continuous observation should be performed after prostatectomy, even if the surgical specimens revealed no carcinoma.

Aged

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

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

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

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

Formation of roseoflavin from guanine through riboflavin.

A synthesis of roseoflavin by Streptomyces davawensis from guanine through riboflavin was demonstrated. The lines of evidence are (1)incorporations of 14C of [2-and U-14C] guanine and [2-14C] riboflavin into roseoflavin, (2) no incorporation of 14C of [8-14C] guanine into roseoflavin, (3) localizations of 14C in roseoflavin, and (4) a decrease of specific radioactivity of roseoflavin formed from [2-14C]guanine on addition of riboflavin to the culture. The 14C atoms in roseoflavin formed were localized by radioactivity analysis of the NaOH-hydrolysis products, i.e., urea and 1,2-dihydro-6-methyl-7-dimethylamino-2-keto-1-D-ribityl-3-quinox-alinecarboxylic acid (QC), a new substance. These hydrolysis products were identified by the isolation of dixanthylures, decomposition with urease, and from the properties of QC and QC tetraacetate isolated. These finding suggest that the pyrimidine ring of guanine is conserved in the formation of roseoflavin from guanine through riboflavin.

Anti-Bacterial Agents