Search PubMed⌕ Search

Biomedical subjects

M Matsuda

Publications and source records attributed to M Matsuda.

At least 1,351 records · Page 75Linked to original sources

Body heat balance and urine excretion during a 4-day saturation dive at 4 ATA.

Five male volunteers were exposed for 4 days to a 4-ATA helium-oxygen saturation dive. Partitional calorimetry was performed during 2-h test periods at various ambient temperatures (Ta). Heat production during the period at 4 ATA in helium-oxygen was identical to that at 1 ATA in air. The nonevaporative heat loss (convective and radiant heat losses) was increased with a concomitant decrease in evaporative heat loss. The mean skin and mean body temperatures fell significantly at 4 ATA, and a slight reduction was observed in the rectal temperature. The conductive heat transfer coefficient from the core to skin (hk) was reduced, probably due to vasoconstriction at 4 ATA. Subjective thermal neutrality at rest at 4 ATA was obtained around Ta = 32 degrees C. A diuresis was observed at 4 ATA, but it disappeared with an increase in chamber temperature. An inverse relationship of urine flow to mean skin temperature was observed. An increase in urine flow at 4 ATA might be attributed to cold stress due to lower skin temperature that was caused by the increased nonevaporative heat loss.

Adult↗

Effect of L-glutamic acid on [14C]GABA release from isolated rat retina.

The effect of various putative neurotransmitters on the release of [14C]GABA taken up by isolated rat retina was investigated by a perfusion technique. L-Glutamic acid initially enhanced the GABA release and subsequently reduced it to a level below the baseline rate. This enhancing effect of L-glutamic acid was Ca2+-dependent and tetrodotoxin-sensitive. L-Aspartic acid only reduced the GABA release, whereas kainic acid exhibited only a marked enhancement of its release. Acetylcholine, norepinephrine, dopamine, glycine and taurine did not have any significant effects on GABA release.

Animals↗

Cytologic characteristics of oat-cell carcinoma of the lung in relation to the effect of chemotherapy.

The cytologic study of the effect of chemotherapy was performed in oat-cell carcinoma of the lung. Cellular characteristics of tumor cells obtained by brushing via bronchoscopy were compared between responders (13 patients in complete and partial regressions) and nonresponders (13 patients with no response) treated with cyclophosphamide. The tumor cells in the responders more frequently showed finely granular chromatin evenly distributed throughout the nuclei. The tumor cells in nonresponders showed predominantly either deeply stained nuclei with coarsely granular chromatin distributed evenly or pale nuclei with unevenly distributed chromatin. These findings were also applied in the evaluation of the effect of combination chemotherapy. The nuclear chromatin pattern from oat-cell carcinoma of the lung may be an indicator to predict the degree of response to chemotherapy.

Aged↗

Solitary ulcer of the rectum: report of a case and review of the literature.

A 13-year-old girl with Prader-Willi syndrome was admitted to our hospital with an 18-month history of anal bleeding and mucus discharge on defecation. Physical examination revealed obesity, hypogonadism, hypotonia and hypomentia. On digital examination, a nodular mass was palpated on the right wall of the ampulla recti, which was suspected to be carcinoma on a barium enema study. Proctoscopic examination revealed a large, irregular ulceration with white slough at the base, surrounded by the nodular and lumpy mucosa. The lesion was excised by the abdomino-anal pull-through method. The resected specimen showed a lesion of large, shallow, irregular ulcer, 5.0 x 2.2 cm in size. Microscopic examination revealed obliterated lamina propria by fibroblasts and muscle fibers derived from the muscularis mucosae, and misplaced cystic dilated glands in the submucosa at the margin of the ulcer. The gross and microscopic appearances are identical to those of "solitary ulcer of the rectum" described by Madigan and others, and similar to those of "colitis cystica profunda" described by Goodall and others. According to these findings, this lesion was diagnosed as solitary ulcer of the rectum. In the present report, the relationship between solitary ulcer of the rectum and colitis cystica profunda was discussed.

Adolescent↗

A case of multifocal proliferations of histiocytic cells containing Langerhans' cell granules.

A 61-year-old male was found to have multiple cutaneous nodules, four subcutaneous tumors, and diffuse small nodular lesions of both lungs. The biopsy specimen of the skin lesions revealed a proliferation of histiocytic cells containing Langerhans' cell granules (Birbeck granules). Chemotherapy including vincristine, cyclophosphamide (endoxan), 6-mercaptopurine, and prednisolone (VEMP) for ten weeks improved the skin lesions, some of which disappeared. After resection of all the remaining skin lesions, there was no recurrence. This case seems to be a special type of eosinophilic granuloma or multicentric reticulohistiocytosis.

Eosinophilic Granuloma↗

The problems in replantation of limbs amputated through the upper arm region.

We performed three replantations at the upper arm: two patients had severely crushed arms and one patient was at advanced age (50 years). One replanted arm was reamputated because of severe neuralgia 1 year, 3 months after replantation. In the other two cases, sensation was recovered to fingertips and powerful motion of the elbow joint was gained. However, pinch or grasp was impossible because of insufficient reinnervation to the extensor muscles. In replantation at the proximal region, recovery of motor function generally tends to be poor especially in a crush injury or in the case of advanced age. Therefore we consider that the decision about arm replantation at the upperarm region should be made more strictly than with a distal amputation.

Amputation, Traumatic↗

Malignant fibrous histiocytoma of bone associated with focal hemangiopericytomatous pattern.

A case of malignant fibrous histiocytoma of the tibia of a 49-year-old Japanese farmer was presented. The patient was diagnosed as malignant hemangiopericytoma by biopsy, whereas the amputated material showed a marked pleomorphism representing features of malignant fibrous histiocytoma. Ultrastructurally, undifferentiated mesenchymal cells, intermediate cells between the undifferentiated mesenchymal cells and fibroblastic cells, fibroblastic cells and histiocytoid cells including bizarre giant cells were confirmed in a broad modulating spectrum. The hemangiopericytomatous lesion was predominated by intermediate cells, the ultrastructure of which bore a close resemblance to that of pericytes, and was regarded to be resulted from a differentiation of undifferentiated mesenchymal cells towards the pericyte.

Bone Neoplasms↗

Characterization of gamma-aminobutyric acid binding sites on crude synaptic membranes.

[3H]GABA binding to crude synaptic membranes of rat brain was studied in an attempt to identify GABA binding to its synaptic receptor in the presence of Na+. Membrane vesicles prepared from crude synaptic membrane fractions were useful as a tool to differentiate synaptic GABA receptors from GABA uptake sites. The crude synaptic membranes treated with Triton X-100 [membranes (TX)] involved two classes of GABA binding sites (KD = 38.7 and 78.0 nM) in the absence of Na+, but the high-affinity sites disappeared in the presence of Na+ and a single class of GABA binding sites (KD = 75.0 nM) was detected. The failure to detect an active uptake of [3H]GABA into the vesicles prepared from membranes (TX) suggests that the [3H]GABA binding in the presence of Na+ was related to synaptic GABA receptors. It is probable that Na+ could mask the presence of the high-affinity class of GABA receptor.

Animals↗

Effects of sodium and bicarbonate ions on gamma-aminobutyric acid receptor binding in synaptic membranes of rat brain.

Crude synaptic membranes treated with Triton X-100 (TX) bound gamma-aminobutyric acid (GABA) to two classes of receptor site in Na+-free 10 mM-Tris-sulfate buffer (pH 7.4), but to only a single class of receptor site in 10 mM Tris-sulfate buffer (pH 7.4), containing 150 mM-NaCl. The high-affinity receptor site in TX membranes was specifically masked in the presence of Na+. However, TX membranes incubated in Krebs-Ringer bicarbonate solution (pH 7.4) bound GABA to two classes of receptor site despite the presence of Na+. It was found that addition of bicarbonate ions to the Na+-containing 10 mM-Tris-sulfate buffer (pH 7.4) could restore that high-affinity class of GABA receptors, rendering both classes detectable. This finding suggests that both Na+ and HCO-3 may have a regulatory function on GABA binding to the receptor.

Animals↗

Influence of sodium-independent gamma-aminobutyric acid binding on the assay of sodium-dependent gamma-aminobutyric acid binding in a membrane preparation of rat brain.

A large amount of [3H]GABA was bound to crude synaptic membrane fractions of rat, by sodium-independent process in a medium that contained 100 microM [3H]GABA used for assaying GABA uptake site. This [3H]-GABA binding was different from receptor binding of GABA. It was confirmed that this sodium-independent [3H]GABA binding scarcely occurred in the presence of a physiological concentration of sodium chloride, and that sodium-independent GABA binding had a negligible influence on sodium-dependent GABA binding.

Animals↗

Evaluation of left ventricular performance and of its reserve by radionuclide angiocardiography: comparison with other methods.

This study was performed, i) to compare radionuclide angiocardiography with the other methods, and ii) to evaluate its usefulness in investigating left ventricular performance and its reserve. Radionuclide angiocardiography, chest X-ray film, chest X-ray cinegraphy, echocardiography, two-dimensional echocardiography, pulsed Doppler flowmetry, cardiokymography, myocardial imaging, contrast ventriculography and coronary arteriography were performed (:also at exercise) in 105 subjects including various kinds of cardiac patients. Radionuclide angiocardiography could be performed both at rest and at exercise, contrary to invasive methods. In detailed analysis of left ventricular mechanics in non-ischemic heart disease, echocardiography at rest and at exercise may be appropriate, because of its high image resolution. In evaluation of ischemic heart diseases, radionuclide angiocardiography at rest and at exercise might be appropriate, because of bidirectional informations and its high success rate. Two-dimensional echocardiography with M-mode echocardiography might compensate for it, particularly for continuous informations during exercise. Detection of regional wall motion dysfunction at exercise is more specific than exercise ECG and is more sensitive than exercise myocardial imaging. From many kinds of examinations, appropriate one should be selected according to the purpose of investigators. Much more technical progress in these methods can be expected.

Adolescent↗

The effects of administration of semicarbazide and aminooxyacetic acid on B6 vitamer levels in subcellular fractions of mouse brain.

The in vivo effects of semicarbazide (SC) and aminooxyacetic acid (AOAA) on the B6 vitamer concentrations in brain subcellular fractions, especially in extrasynaptosomal, synaptosomal plasma, extrasynaptosomal and synaptosomal mitochondria, were investigated. Treatment of mice with SC decreased levels of pyridoxal phosphate (PLP) in extrasynaptosomal and synaptosomal plasma, while it had no effect on those in extrasynaptosomal and synaptosomal mitochondria. On the contrary, treatment with AOAA more significantly decreased pyridoxamine phosphate (PMP) levels in extrasynaptosomal and synaptosomal mitochondria than those in extrasynaptosomal and synaptosomal plasma. According to these results, the difference between in vivo effects of SC and AOAA on vitamin B6-enzymes was discussed.

Acetates↗