Search PubMed⌕ Search

Biomedical subjects

M Matsuda

Publications and source records attributed to M Matsuda.

At least 1,513 records · Page 84Linked to original sources
PubMed1977

gamma-Aminobutyric acid metabolism in subcellular particles of mouse brain and its relationship to convulsions.

The in vivo effects of convulsant drugs (hydrazine and penicillamine) on the metabolism of gamma-aminobutyric acid (GABA) in subcellular fractions of mouse brain were studied. Both substances inhibited the activity of glutamic acid decarboxylase [EC 4.1.1.15] (GAD) in the synaptosomal fraction (nerve ending particles) and reduced the concentration of GABA in the same fraction at the onset of convulsions, though changes in the total GABA concentration in the brain did not correlate with the onset of convulsions. Therefore, it is suggested that the concomitant decrease of GAD activity and GABA concentration in the nerve endings, independently of the total GABA concentration, is probably an important factor in the onset of some kinds of convulsions.

4-Aminobutyrate Transaminase↗
PubMed1977

The behavior of alpha2-plasmin inhibitor in fibrinolytic states.

Human plasma alpha2-plasmin inhibitor in fibrinolytic states was studied using immunochemical methods and radioiodinated plasminogen. The concentration and activity of plasma alpha2-plasmin inhibitor decreased when urokinase was added to plasma in vitro or infused intravenously in man. The decrease was associated with the appearance of plasmin-alpha2-plasmin inhibitor complex which subsequently disappeared from the circulation in a short time. A decrease of other major inhibitors, such as alpha2-macroglobulin and alpha1-antitrypsin, was not observed when the amount of urokinase added or infused was relatively small, and conversion of plasminogen to plasmin was not extensive. The formation of plasmin-alpha2-macroglobulin complex was observed only when plasma plasminogen was activated with a larger amount of urokinase, and after most of the alpha2-plasmin inhibitor was consumed by forming complexes with plasmin. The formation of plasmin-alpha1-antitrypsin complex was not observed even in the highly activated plasma unless exogenous plasmin was added to the plasma. alpha2-Plasmin inhibitor was the only inhibitor of which the concentration in plasma was significantly decreased in patients with disseminated intravascular coagulation and fibrinolysis among the major plasmin inhibitors in plasma. The most reactive inhibitor for regulating plasma fibrinolysis very likely is alpha2-plasmin inhibitor.

Alpha-Globulins↗
PubMed1977

Systolic time intervals in patients with progressive muscular dystrophy of the Duchenne type.

Systolic time intervals (STIs) were measured in 57 patients with progressive muscular dystrophy (PMD) of the Duchenne type, and were correlated with the stages of physical disability. The total electromechanical systole (Q-A2), pre-ejection period (PEP), and left ventricular ejection time (LVET) were corrected for heart rate using the linear regression equations calculated from 91 normal subjects. Each systolic time interval index (STII), i.e. corrected STI, was analyzed. In 15 ambulatory patients (Group P-1), the STIIs did not differ significantly from those in normal controls. In 37 patients who were unable to walk (Group P-2) and 5 patients who were confined to bed (Group P-3), there was a significant increase (p less than 0.001) in the PEP index (PEPI), a decrease (p less than 0.001) in the LVET index (LVETI), and an increase (p less than 0.001) in the PEP/LVET compared with those in controls. The PEPI (p less than 0.001), LVETI (p less than 0.025), and PEP/LVET (p less than 0.001) in Group P-2 differed significantly from those in Group P-1. In Group P-3, the PEPI (p less than 0.005), LVET (p less than 0.001), and PEP/LVET (p less than 0.001) were significantly changed in comparison with those in Group P-2. Remarkable myocardial histopathologic changes suggestive of dystrophy were revealed in autopsies of 3 patients who had been in the severely disabled stage and had shown impaired STIs. It is suggested that cardiac function in patients with moderate to advanced PMD of the Duchenne type is deteriorated in proportion to the disability stages, i.e. the severity of changes in the skeletal muscles.

Adolescent↗
PubMed1977

Effects of cyclic AMP and dibutyryl cyclic AMP on cerebral hemodynamics and metabolism in the baboon.

Adenosine 3',5'-cycle monophosphate (cyclic AMP) (0.5 mg/kg) was infused into the carotid artery of baboons anesthesized with sodium pentobarbital, causing a biphasic increase in cerebral blood flow (CBF) and reduction in cerebrovascular resistance (CVR) associated in each phase with stimulation of cerebral metabolism evidenced by increased cerebral oxygen consumption (COMRO2) and cerebral glucose consumption (CMRG1). Intracarotid dibutyryl cyclic AMP (0.5 mg/kg) caused a monophasic increase in CBF and reduction of CVR but failed to alter cerebral metabolism. This may be due to its rapid removal from the circulation with ineffective passage across the blood-brain barrier since intracisternal infusion of dibutyryl cyclic AMP caused sustained increase in CBF, CMRO2 and CMRG1 and reduction in CVR. Intracarotid AMP (0.4 mg/kg) and adenosine (0.3 mg/kg) caused an immediate and more marked increase in CBF and decrease in CVR unassociated with cerebral metabolic change making it unlikely that the observed effects of cyclic AMP can be attributed to its breakdown products. Cyclic AMP or its dibutyryl derivative may alter cerebral metabolism secondary to neuronal activation but increase in glucose/oxygen utilization ratio after intracarotid cyclic AMP and intracisternal dibutytyl cyclic AMP also suggests an influence on enzymatic regulation of glucose metabolism.

Adenosine↗
PubMed1977

Isolation and some properties of nontoxigenic derivatives of a strain of Clostridium tetani.

Nontoxigenic derivatives of a toxigenic strain of Clostridium tetani were isolated gy treatment with acridine orange, N-methyl-N'-nitro-soguanidine, rifampicin or ultraviolet light. The frequency of appearance fo non-toxigenic derivatives on these treatments was 0.8 to 3.2 per cent. The nontoxigenic derivatives peoduced all the same extracellular antigenic and protein components as the toxigenic parent strain, except the toxin and materials cross-reacting with the toxin. The nontoxigenic strains, like the toxigenic parent strain, were lyzed by trratment with mitomycin C. Bacteriophage was detected in the lysates of all the nontoxigenic derivatives produced with mitomycin C, and this bacteriophage was morphologically indistinguishable from that obtained from the toxigenic parent strain. The genetic factor controlling tetanus toxin production is discussed.

Antigens, Bacterial↗
PubMed1977

Surgical treatment of intracranial hematoma and hydrocephalus in an infant with hemophilia A.

A seven-month0old hemophiliac infant developed intracerebral, subdural and intraventricular hematomas and hydrocephalus. Removal of hematomas and placement of ventriculoperitoneal shunt could be performed quite safely even in an infant under the cover of highly potent human antihemophilic factor concentrate. Computerized tomography is very useful for neurosurgical care of the hemophiliac patients as a noninvasive and atraumatic method of examination. Intracranial bleeding is listed as the most common cause of death among hemophiliacs. The literature of intracranial operations on the patients with hemophilia A is reviewed.

Cerebral Hemorrhage↗
PubMed1977

Hana Kai II: a 17-day dry saturation dive at 18.6 ATA. I. Objectives, design, and scope.

The dive (Hana Kai II) described in these papers was designed to determine the effects on man of a prolonged exposure to a dry helium-oxygen hyperbaric environment. Comprehensive studies on energy balance, body fluid balance, cardiorespiratory functions, maximal oxygen uptake, psychological performance, and physiological responses to cold were performed at a simulated depth of 580 ft (18.6 ATA) over a 30-day period in March-April 1975. Following a 3-day predive control period at 1 ATA air (period 1), 5 male divers spent 17 days at 18.6 ATA in a helium-oxygen environment (periods 2-6), and returned to 1 ATA air after 7 days of decompression (periods 7-8). They stayed an additional 3 days inside the chamber for postdive control measurements (period 9). The chamber temperature was maintained at 25-27 degrees C during periods 1 and 9, 30-31 degrees C during periods 2-5, and 27-28 degrees C during period 6. At 18.6 ATA, the PO2 and PCO2 of the chamber gas were maintained at approximately 225 and 2 mmHg, respectively. In this introductory paper, physical and physiological characteristics of individual subjects, the major daily activity schedule, and the scope of investigation are presented.

Activities of Daily Living↗