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Biomedical subjects

K Matsuda

Publications and source records attributed to K Matsuda.

At least 559 records · Page 31Linked to original sources
PubMed1989

Correlation between culture medium pH, extracellular proteinase activity, and cell growth of Candida albicans in insoluble stratum corneum-supplemented media.

Candida albicans produces a major extracellular proteinase whose activities are observed only in weakly acidic pH. However, in affected lesions, a variety of pH conditions exist, including neutral pH. To verify the pathological importance of the extracellular proteinase, the correlation between culture medium pH, extracellular proteinase activity, and cell growth of C. albicans was followed for 3 weeks with unbuffered and insoluble stratum corneum-supplemented liquid media. Each medium pH, initially adjusted within a range of pH 3-7 by the addition of sodium hydroxide or hydrochloric acid solution, was acidified, and a subsequent high proteolytic activity and rapid fungal growth were observed. After full fungal growth, neutralization of each medium to pH 7 and reduction of proteinase activity occurred. Results from a glucose addition experiment suggest that acidification of each medium was produced by the acid formation from glucose and neutralization by the exhaustion of glucose and increase of ammonia from denatured stratum corneum. These data suggest that extracellular proteinase from C. albicans could act as a virulence factor under a wide range of pH conditions by the acidification of the environmental pH close to the organism.

Ammonia↗
PubMed1989

Biochemical examination on the increased superoxide dismutase-like plasma substance observed in a state of acute gastric mucosal lesions.

When experimental acute gastric mucosal lesions were produced in guinea pig by water-immersion and restraint stress, superoxide dismutase (SOD)-like substance in the plasma increased. On analysis by gel filtration, it was shown that the molecular weight of the increased SOD-like plasma substance was about 130,000, and even after treatment with trypsin, 84% of this substance remained. Since the molecular weight of intracellular SOD is about 40,000, it seems that this substance is similar to extracellular SOD, located on the endothelial cell-surface, as previously reported by Marklund et al. Our results suggest that in the presence of acute gastric mucosal lesions, SOD-like plasma substance is not identical to intracellular SOD, which derived from cell destruction by stress or free radical-induced microvascular damage or by hemolysis. Furthermore, this substance may itself work as a scavenger of free radicals generated under conditions, such as these described in the present experiment.

Animals↗
PubMed1989

Intra- and extracellular distribution and immunochemical characterization of hepatitis B virus nucleocapsid proteins produced by a human hepatoma cell line transfected with cloned viral DNA.

Hepatitis B virus (HBV)-related antigens produced by the human hepatoma cell line (HB611 cell), which had been transfected with a cloned HBV DNA and established as a stable producer of HBV (T. Tsurimoto, A. Fujiyama, and K. Matsubara, 1987, Proc. Natl. Acad. Sci. USA 84, 444-448), were investigated immunochemically and morphologically. All HBV-related antigens, HBV surface (HBsAg), e (HBeAg), and core (HBcAg), were semiquantitatively examined by the respective reversed passive hemagglutination assay (RPHA). RPHAs for HBcAg and for HBeAg were characterized as reacting only to the core particles and to the free form of nucleocapsid proteins, respectively. The amounts of HBsAg and nucleocapsid protein in culture medium were roughly related to the number of viable cells. The amount of core particles was, instead, proportional to the number of dead cells. Relative amounts of HBsAg, core particles, and nucleocapsid proteins in culture medium, cell surface, and cell lysate were determined and it was found that HBsAg and nucleocapsid proteins were effectively secreted into culture medium but core particles were not. Molecular species of nucleocapsid proteins were identified to be p17 and p18 (HBeAg polypeptides) in the culture medium and HBeAg polypeptides and p21.5 (HBcAg polypeptide) in the cytosol fraction. The p21.5 was preferentially found in the nuclear fraction.

Carcinoma, Hepatocellular↗
PubMed1989

Synthesis and thromboxane synthetase inhibitory activity of di- or tetrahydrobenzo[b]thiophenecarboxylic acid derivatives.

1-Imidazolylalkyl-substituted di- or tetrahydrobenzo[b]thiophenecarboxylic acid derivatives and related compounds were synthesized from tetrahydrobenzo[b]thiophene derivatives (1 or 4) in order to study the structure-activity relationships of the inhibition of thromboxane A2 synthetase in vitro. Sodium 2-(1-imidazolylmethyl)-4,5-dihydrobenzo[b]thiophene-6-carboxylate (26) and 2-(1-imidazolylmethyl)-4,5,6,7-tetrahydrobenzo[b]thiophene-6-carbo xylic acid hydrochloride (28) showed the most potent and specific activity in vitro for thromboxane A2 synthetase inhibition.

Animals↗
PubMed1989

Modification of essential carboxyl group in rabbit muscle phosphorylase by water-soluble carbodiimide.

Water-soluble carbodiimide (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) (EDC) and glycine ethyl ester (GEE) as a nucleophile were used to modify the essential carboxyl group of phosphorylases. The inactive b form of the muscle phosphorylase was modified faster than the active a form and potato phosphorylases. Use of N,N,N',N'-tetramethyl-ethylenediamine (TEMED)-HCl buffer system (pH 6.2) resulted in a remarkable difference from the previous results obtained with phosphate and beta-glycerophosphate buffer systems. That is, the substrate glucose 1-phosphate gave the best protection of the three phosphorylase activities. Glucose and glycogen were also effective to retard the inactivation of muscle phosphorylases, though glycogen was not effective for the potato enzyme. The EDC-GEE-modified phosphorylase b retained the affinity for AMP-Sepharose, though partially modified enzyme completely lost the homotropic cooperativity. Phosphorylase b was subjected to differential labeling with [14C]GEE. A labeled peptide was obtained after CNBr cleavage and peptic digestions, and corresponded to the catalytic site sequence surrounding the GEE-substituted Asp 661 and Glu 664. Either or both of these EDC-modified carboxyl residues may have an important role in the catalytic reaction.

Amino Acids↗
PubMed1989

Focal CT abnormality and epileptogenic focus.

In 31 patients with temporal lobe epilepsy, the precise site of epileptogenic focus was determined by means of a depth EEG recording as one of the presurgical evaluations. In 13 patients, a CT scan revealed focal lesions; 7 in the left temporal lobe and 6 in the right temporal lobe. In 5 of the 7 patients and in 5 of the 6 patients the epileptogenic foci were determined in the temporal lobe on the side of a CT lesion. However, in 2 of the patients with a CT lesion in the left temporal lobe, independent epileptogenic foci were found in both the temporal lobes, and in the other patient with a CT lesion in the right temporal lobe, they were found in the right frontal and left temporal lobes. Thus, the CT lesions agreed in lateralization and focality with the epileptogenic foci in 10 of the 13 patients (77%), but they disagreed in 3 (23%). A CT lesion disclosed in the temporal lobe does not necessarily indicate the side and/or site where the epileptogenic focus may be localized. Although exceptions may be made, spatial disagreement was exemplified between the CT lesion and epileptogenic focus. Therefore, extreme caution has to be taken on the side and/or site of the epileptogenic focus when functional surgical indication is to be made.

Adolescent↗
PubMed1989

MRI lesion and epileptogenic focus in temporal lobe epilepsy.

The spatial relationship between a circumscribed lesion in the temporal lobe detected by MRI and an epileptogenic focus identified by ictal depth EEG along with a correlation of the MRI lesion with neuropathological findings were investigated in patients with medically intractable temporal lobe epilepsy but without any focal lesion on CT. Four parameters (an areal ratio of the temporal lobe against the hemisphere, area and calculated T1, T2 values of the hippocampus) were used to determine the abnormal MRI side. An agreement was reached in 67-72% of 18 patients between the abnormal values of the hippocampal area and of calculated T1, T2 and the side of the epileptogenic focus. In 14 of 17 patients, typical hippocampal sclerosis was demonstrated in resected tissue in accordance with the MRI lesions (atrophy and/or prolonged T2 of hippocampus). These results imply: 1) MRI abnormality thus defined may, if not all, indicate the side of the epileptogenic focus, and 2) also the presence of hippocampal sclerosis. It was emphasized that the MRI lesion would be a usable instrument to explore the causal relationship of hippocampal sclerosis to a generation of epileptogenic lesions as well as for presurgical evaluation.

Adolescent↗
PubMed1989

Emotional facial expressions at the onset of temporal lobe seizures: observations on scalp and intracranial EEG recordings.

The initial facial expressions of 195 complex partial seizures of 98 patients with temporal lobe epilepsy were reviewed in relation to the laterality and focality of electroencephalographic (EEG) seizure origin. A neutral expression was observed most often (71) followed in frequency by expressions of disgust (13), happiness (7) and sadness (7). There was no expression of anger, surprise and fear. No correlation was found between the type of facial expression and the side of seizure origin. However, among 27 patients examined by means of intracranial EEG recordings, it was evident that a disgust expression occurred with oro-alimentary automatisms at the beginning of mesial temporal lobe seizures, whereas a happy one occurred without oro-alimentary automatisms at the beginning of lateral temporal lobe seizures. Although the facial expressions were not always related to the concurrent ictal emotion, it appeared that the majority of the patients with the disgust expression had autonomic features, while those of the happy/sad expression had psychic/sensory ones. It was concluded that (1) a disgust expression occurs as an indirect consequence of "crude sensation," while a happy/sad expression occurs as a direct consequence of "elaborate mental state" (Jackson) and (2) facial expressions must be reviewed in relation to focality rather than laterality in temporal lobe seizures.

Adolescent↗
PubMed1989

A correlative study between hippocampal atrophy quantified by tomo-pneumoencephalography and epileptogenic focus in temporal lobe epilepsy.

It appeared certain that we can quantify the rate of hippocampal atrophy by utilizing the sagittal cuts in tomo-pneumoencephalography. This is a reliable method to infer the side of the epileptogenic focus in temporal lobe epilepsy since a close correlation was disclosed between the side with more atrophic features of the hippocampus and that of the epileptogenic focus explored by depth EEG, in particular, in the mesial temporal focus group. On the other hand, it seems to be plausible that the hippocampal atrophy could be secondarily induced by epileptic discharges in the lateral temporal group. Namely, controversies dealing with the casual relationship of hippocampal atrophy should be discussed based on the epileptogenic focus localization in temporal lobe epilepsy.

Amygdala↗
PubMed1989

Experimental study on the adsorption of excess heparin with anion exchange resin fiber.

Anion exchange resin fiber (Ionex) was used as a heparin adsorbent. Ionex has the adsorption capacity of 70 mg/g (weight by desiccation) for heparin, and was used in an attempt to remove the heparin from blood-perfused artificial organs, before the blood was transfused back into the patients. In the ex vivo study, the 5 systemically heparinized dogs (500 U/kg) were treated with a 35-40 g column of Ionex, by direct hemoperfusion (DHP). The concentration of heparin was significantly reduced, within 15 to 60 minutes, using the Ionex. This suggested the possibility of removing excess heparin from the living body. In in vitro, the relationship between the amount of heparin by Ionex and the blood-flow volume were evaluated. Whole blood taken from dogs was added to 5 U/ml of heparin. This was then introduced into a small column containing 0.9 g Ionex, at blood-flow rates of 0.8, 1.6, and 3.2 ml/min. A good adsorption capacity was shown at the blood-flow rate of 0.8 ml/min. One possible explanation for this is that the heparin dispersed in the blood cells gradually was passed on into the plasma and, so, did not have time to be adsorbed at the faster flow rates.

Adsorption↗
PubMed1989

In vitro and in vivo antibacterial activities of BO-1341, a new antipseudomonal cephalosporin.

BO-1341, a new antipseudomonal semisynthetic cephalosporin, was evaluated for in vitro and in vivo antibacterial activities in comparison with ceftazidime, cefotaxime, and cefoperazone. The in vitro activity of BO-1341 was generally superior or comparable to the activities of the reference antibiotics against clinical isolates of the family Enterobacteriaceae. BO-1341 was highly active against Pseudomonas aeruginosa (MIC for 90% of the strains tested, 1.56 micrograms/ml), Pseudomonas maltophilia (MIC for 50% of the strains tested, 1.56 micrograms/ml), and Acinetobacter calcoaceticus (MIC for 90% of the strains tested, 3.13 micrograms/ml). Furthermore, BO-1341 was highly active against P. aeruginosa isolates resistant to the other antibiotics. Of 199 P. aeruginosa isolates tested, only 2 were resistant to BO-1341. These two strains were also resistant to ceftazidime, cefotaxime, and cefoperazone. Haemophilus influenzae, Branhamella catarrhalis, and nonenteric streptococci were also susceptible to BO-1341, but Staphylococcus aureus, Streptococcus faecalis, and Bacteroides fragilis were not susceptible to the compound. The protective efficacy against experimental infections in mice caused by nine strains of gram-negative bacteria, including P. aeruginosa, reflected the potent in vitro activity.

Animals↗
PubMed1989

A longitudinal assessment of haloperidol doses and serum concentrations in Asian and Caucasian schizophrenic patients.

Over 3 months, 13 Caucasian and 16 Asian schizophrenic patients were sequentially treated with weight-adjusted fixed doses and clinically determined, variable doses of haloperidol. During the fixed-dose phase, Asians had a slightly higher mean serum haloperidol concentration and a significantly higher rating for extrapyramidal symptoms. During the variable-dose phase, the Asian patients' mean required dose was significantly lower, resulting in lower serum haloperidol concentrations at the first emergence of extrapyramidal symptoms and for optimal clinical response. These results indicate pharmacodynamic differences in therapeutic response but no significant difference in steady-state serum concentration between the two groups.

Adult↗
PubMed1989

Effects of coronary artery bypass surgery on regions showing persistent defects in thallium myocardial images.

The indications for revascularization surgery and its effects on myocardial regions showing persistent defects in thallium myocardial images are controversial. The effects of aortocoronary bypass surgery on myocardial perfusion and wall motion in the regions with persistent defects were evaluated in 47 patients with thallium-201 single photon emission computed tomography and left ventriculography. In areas showing persistent thallium defects preoperatively the rate of improvement of perfusion was only 24% by postoperative thallium imaging, and 57% by wall motion analysis. These results were significantly inferior to those of regions with transient defects, which were 84% and 82%, respectively. A persistent defect may not be a definitive marker of a non-viable scar, but the results of surgery on such regions were unsatisfactory. It is concluded, therefore, that revascuralization surgery in regions with persistent defects is not always recommended and that the indications for surgery should be individually determined with operative risk balanced against benefits.

Adult↗
PubMed1989

A case of primary aldosteronism with chronic renal failure undergoing hemodialysis treatment.

A 56-year-old man with primary aldosteronism and chronic renal failure undergoing hemodialysis is described. He complained of numbness of the extremities and showed persistent hypopotassemia in spite of anuria. In the endocrinological examination, a very high plasma aldosterone concentration was observed, while plasma renin activity was within the normal range. From the abdominal Computed Tomography (CT), adrenal scintigraphy, and segmental venous sampling data, he was diagnosed as primary aldosteronism due to left adrenocortical adenoma. In this case, hypopotassemia could not be explained by potassium loss through the kidneys, which suggests potassium excretion in the gastrointestinal tract as the mechanism of hypopotassemia. This was clearly shown from a potassium-balance study and the results of spironolactone administration. Our report is on the first case showing hypopotassemia due to primary aldosteronism in spite of anuria. If a patient treated with maintenance dialysis should have persistent hypopotassemia, as in the present report, it is necessary to consider an association with primary aldosteronism.

Humans↗