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Biomedical subjects

M Miyachi

Publications and source records attributed to M Miyachi.

At least 55 records · Page 3Linked to original sources
PubMed1994

Kupffer cells cytotoxicity against hepatoma cells is related to nitric oxide.

We have previously demonstrated that rat resting macrophages have cytotoxicity against tumor cells. In the current study we have performed an in vitro experiment to explore the mechanism of Kupffer cells-mediated cytotoxicity against hepatomas. The coculture of tumor cells with Kupffer cells (derived from rat livers) stimulated syngeneic and allogeneic Kupffer cells to produce nitric oxide. Kupffer cell-mediated cytotoxicity was paralleled to the amount of nitric oxide and was abolished by the addition of NG-monomethyl-L-arginine. The ability to stimulate Kupffer cells to produce nitric oxide resided on the membranous fragment of tumor cells.

Animals↗
PubMed1994

The effect of epidural morphine on human intestinal motility in the early postoperative period.

The early postoperative recovery of intestinal motility and the response of motility to epidural morphine were investigated in 20 patients. Periodic motor activities in the jejunum were recovered within 32 hours in all cases. The length of these cycles increased gradually from the 1st (23.2 min) to the 4th (41.7 min) postoperative day. Morphine and lignocaine were given through an epidural catheter. Morphine induced premature migrating motor complexes (MMC) in all cases, whereas lidocaine failed to evoke this response in every case. The mean duration (19.8 min) and maximal amplitude (62.8 mmHg) of the burst activities induced by morphine were significantly longer and higher than those occurring spontaneously (7.7 min and 35.6 mmHg, respectively). The intervals between the induced and the subsequent spontaneous contractions were the same as the intervals between spontaneous contractions. These observations indicate that epidural morphine induced premature MMC without interrupting recovery patterns from postoperative gastrointestinal paralysis.

Adult↗
PubMed1994

[A new index of acceleration plethysmogram and its clinical physiological evaluation].

The purposes of the present study were to examine a new index of acceleratingly plethysmogram (APG) and to discuss the possibility to apply the APG index. One hundred sixty-three subjects voluntarily participated in the present study. The mean values (n = 10) of individual coefficient of variance were 7.22% in wave height B, 8.26% in the total area of the lower part under the base line, and 7.28% in a new APG index. The coefficient of variance in the APG index calculated from the previous method (18.67%) was larger than that of the present study. We recognized the significantly polynomial relationship between the new APG index and types of APG. Further, the value of new APG index remarkably increased when the index was beyond 50. There were significant differences in age, blood pressure, rate of body fat, blood glucose, total cholesterol, HDL cholesterol, and index of arteriosclerosis between above 50 and below 50 in the new APG index. These results suggest that the present APG index is adequate about about the individual reproducibility, and it has the possibility to apply as an index of arteriosclerosis.

Adult↗
PubMed1993

Purification and sequence determination of heat-stable enterotoxin elaborated by a cholera toxin-producing strain of Vibrio cholerae O1.

Four molecular species of heat-stable enterotoxins elaborated by a cholera toxin-producing strain of Vibrio cholerae O1 were isolated from its culture supernatant. The amino acid sequence of one of the enterotoxins was determined to be Phe-Ile-Lys-Gln-Val-Asp-Glu-Asn-Gly-Asn-Leu-Ile-Asp-Cys-Cys-Glu-Ile-Cys- Cys-Asn-Pro-Ala-Cys-Phe-Gly-Cys-Leu-Asn with three intramolecular disulfide linkages. The other enterotoxins had shorter amino acid sequences in the N-terminal regions, but possessed the same sequence in their C-terminal regions including the three disulfide linkages. The enterotoxins with the shorter N-terminal sequences showed more potent toxicities, and the minimum effective dose of the longest one with 28 amino acid residues was 10-folds of that of the shortest one.

Amino Acid Sequence↗
PubMed1992

Identification and characterization of apolipoprotein(AII-E2-AII) complex in human plasma lipoprotein.

A new apolipoprotein complex designated as the apo(AII-E2-AII) complex was identified in the lipoprotein fractions of human plasma with apoE phenotypes containing apoE2 (E4/E2, E3/E2, and E2/E2). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by an immunoblotting assay using anti-apoE or anti-apoAII antibodies, established that the apo(AII-E2-AII) complex, with a molecular weight of 58,000, was identical to the complex consisting of apoE and apoAII, and that it also dissociated following reduction with beta-mercaptoethanol. This new complex was also demonstrated to be distinct from the apo(E-AII) complex and apoE monomer by isoelectric focusing, in the samples that were not treated with beta-mercaptoethanol. In apoE phenotype E3/E2, the apo(AII-E2-AII) complex was primarily included in the high-density lipoprotein (HDL, 1.063 < d < 1.21 g/ml) fraction, but was also observed in a small quantity in the very-low-density lipoprotein (VLDL, d < 1.006 g/ml) fraction. For further characterization, the apo(AII-E2-AII) complex was isolated by preparative SDS-PAGE, and no contamination of apo(E-AII) complex and apoE monomer was detected by immunoblotting assay using an anti-apoE antibody. It was confirmed by an enzyme-linked immunosorbent assay (ELISA) system that a molecular ratio between apoAII monomer and apoE in the isolated apo(AII-E2-AII) complex was approx. 2, when the apo(E-AII) complex was used as a standard with the ratio of 1:1. It indicates that the apo(AII-E2-AII) complex is formed from two molecules of apoAII monomer and one molecule of apoE.(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoprotein A-II↗
PubMed1992

Mesenteric vasoconstriction in cardiogenic shock in pigs.

The quantitative impact of mesenteric vasoconstriction on the systemic hemodynamic response to cardiogenic shock induced by pericardial tamponade was evaluated. Graded increases in pericardial pressure produced corresponding decreases in cardiac output to 44% +/- 2% and arterial pressure to 64% +/- 3% of baseline and increases in total peripheral vascular resistance to 131% +/- 4% of baseline. Total mesenteric blood flow decreased disproportionately, to 28% +/- 3% of baseline, because of a disproportionate increase in mesenteric vascular resistance to 223% +/- 6% of baseline. Nonmesenteric vascular resistance increased only to 119% +/- 4% of baseline. Thus mesenteric vasoconstriction accounted for 42% of the increase in total peripheral resistance. Prior blockade of the renin-angiotensin axis ablated this response and eliminated the mesenteric contribution to systemic vascular resistance, while confirmed blockade of the alpha-adrenergic system or vasopressin system had no effect. Without shock, central intravenous infusions of angiotensin II (but not norepinephrine or vasopressin) closely mimicked this selective vasoconstriction. Angiotensin-mediated selective mesenteric vasoconstriction accounts for more than 40% of the overall increase in systemic vascular resistance in cardiogenic shock.

Animals↗
PubMed1992

Relationship between arterial oxygen desaturation and ventilation during maximal exercise.

The purpose of the present study was to investigate the contribution of ventilation to arterial O2 desaturation during maximal exercise. Nine untrained subjects and 22 trained long-distance runners [age 18-36 yr, maximal O2 uptake (VO2max) 48-74 ml.min-1 x kg-1] volunteered to participate in the study. The subjects performed an incremental exhaustive cycle ergometry test at 70 rpm of pedaling frequency, during which arterial O2 saturation (SaO2) and ventilatory data were collected every minute. SaO2 was estimated with a pulse oximeter. A significant positive correlation was found between SaO2 and end-tidal PO2 (PETO2; r = 0.72, r2 = 0.52, P < 0.001) during maximal exercise. These statistical results suggest that approximately 50% of the variability of SaO2 can be accounted for by differences in PETO2, which reflects alveolar PO2. Furthermore, PETO2 was highly correlated with the ventilatory equivalent for O2 (VE/VO2; r = 0.91, P < 0.001), which indicates that PETO2 could be the result of ventilation stimulated by maximal exercise. Finally, SaO2 was positively related to VE/VO2 during maximal exercise (r = 0.74, r2 = 0.55, P < 0.001). Therefore, one-half of the arterial O2 desaturation occurring during maximal exercise may be explained by less hyperventilation, specifically for our subjects, who demonstrated a wide range of trained states. Furthermore, we found an indirect positive correlation between SaO2 and ventilatory response to CO2 at rest (r = 0.45, P < 0.05), which was mediated by ventilation during maximal exercise. These data also suggest that ventilation is an important factor for arterial O2 desaturation during maximal exercise.

Adult↗
PubMed1992

Ventilatory capacity and exercise-induced arterial desaturation of highly trained endurance athletes.

Recent evidence suggested that exercise-induced arterial O2 desaturation may occur in highly trained endurance athletes. So, Dempsey brought the hypothesis that the pulmonary capacity for oxygen transport cannot meet superior demands imposed by cardiovascular system in highly trained endurance athletes, and endurance training primarily causes adaptation in the skeletal muscles and in the systemic cardiovascular system, with little change in the pulmonary system. In the present study, we determined the propriety of the hypothesis due to measure the ventilatory capacity of endurance athletes. Sixteen highly trained endurance athletes (ET) and thirteen untrained subjects (UT) volunteered to participate in these experiments. All subjects performed the four experiments, 1) the highest oxygen uptake (peak VO2) during incremental cycle exercise and ventilation (VE), ventilatory equivalent for O2 (VE/VO2) and arterial O2 saturation (SaO2) at which peak VO2 was observed, 2) the maximal voluntary ventilation for 30 sec at rest (MVV), 3) the pulmonary diffusing capacity for CO (DLCO) and expressed per unit of alveolar lung volume (KCO) at rest by the single breath method, and 4) the ventilatory response to hypercapnia (S) at rest by rebreathing method, were measured. The peak VO2 of ET (66.7 ml.min-1.kg-1) was significantly (30.8%) higher than UT (52.4 ml.min-1.kg-1), and VE/VO2 and SaO2 of ET (29.3 and 93.7%, respectively) were significantly lower than UT (34.6 and 95.8%). There were no differences in VE, MVV, DLCO, and S between two groups.

Adult↗
PubMed1992

[Diagnosis and management of benign biliary strictures with percutaneous transhepatic cholangioscopy (PTCS)].

From January 1981 through March 1991, we encountered twenty four cases of benign biliary strictures. In 10 cases of anastomotic stricture, percutaneous dilatation was carried out in 1 patient under fluoroscopy and in 3 patients under PTCS without recurrence. Endoprosthesis with silicone or polyurethane catheters was carried out under PTCS in 5 patients. One of them died of hepatic failure due to clogging of the catheter, and in other four patients the endoprosthetic catheter was dislodged spontaneously or removed by PTCS because of dislodgement or obstruction of the catheter, and PTCS revealed that the anastomotic stricture had improved. Reoperation of cholangiojejunostomy was carried out in 1 patient, who died of hepatic failure 5 years later due to recurrent of stricture. In 8 cases of the iatrogenic and 1 case of traumatic stricture, percutaneous dilatation was carried out (1 under fluoroscopy and 4 under PTCS) without recurrence. Cholangiojejunostomy was carried out in 3 cases without anastomotic stricture. PTCS was performed for 5 cases of the inflammatory stricture of the hepatic hilus due to cholecystitis to confirm the histological findings by cholangioscopic biopsy. And all cases could be managed by cholecystectomy. Authors recommend that PTCS should be used for the diagnosis and treatment of benign biliary stricture.

Aged↗
PubMed1991

Effect of low blood glucose on plasma CRF, ACTH, and cortisol during prolonged physical exercise.

The effects of low blood glucose concentration during low-intensity prolonged physical exercise on the hypothalamus-pituitary-adrenocortical axis were investigated in healthy young men. In experiment 1, six subjects who had fasted for 14 h performed bicycle exercise at 50% of their maximal O2 uptake until exhaustion. At the end of the exercise, adrenocorticotropic hormone (ACTH) and cortisol increased significantly. However, this hormonal response was totally abolished when the same subjects exercised at the same intensity while blood glucose concentrations were maintained at the preexercise level. In experiment 2, in addition to ACTH and cortisol, the possible changes in plasma concentration of corticotropin-releasing factor (CRF) were investigated during exercise of the same intensity performed by six subjects. As suggested by a previous study (Tabata et al. Clin. Physiol. Oxf. 4: 299-307, 1984), when the blood glucose concentrations decreased to less than 3.3 mM, plasma concentrations of CRF, ACTH, and cortisol showed a significant increase. At exhaustion, further increases were observed in plasma CRF, ACTH, and cortisol concentrations. These results demonstrate that decreases in blood glucose concentration trigger the pituitary-adrenocortical axis to enhance secretion of ACTH and cortisol during low-intensity prolonged exercise in humans. The data also might suggest that this activation is due to increased concentration of CRF, which was shown to increase when blood glucose concentration decreased to a critical level of 3.3 mM.

Adrenocorticotropic Hormone↗
PubMed1991

Development of an enzyme-linked immunosorbent assay of apolipoprotein E-AII complex in plasma.

Measurement of apolipoprotein (apo) E-AII complex in human plasma is important in determining the role of apoE in lipoprotein metabolism. In this paper, we demonstrate a new and simple method to determine apoE-All complex by using an enzyme-linked immunosorbent assay. Anti-apoE IgG (goat) was used as a capture antibody, and captured apoE-All complexes were detected by an anti-apoAll (rabbit) horseradish peroxidase-conjugated anti-rabbit IgG (goat) system. With this method, apoE-All complex was specifically determined without the interference of apoAll and was not affected by apoE monomer less than 250 mg/L. The content of the complex in reference serum, a normolipidemic serum pooled from five subjects with phenotype E3/E3, was arbitrarily defined as 100%. The coefficients of variation were 3.5%-6.3% within assay and 8.8%-11.6% between assays.

Apolipoproteins E↗
PubMed1990

Griffonia simplicifolia agglutinin-2-binding glycoprotein as a novel carbohydrate antigen of human colonic carcinoma.

Griffonia simplicifolia agglutinin-2-binding glycoprotein (GBG) in human colonic carcinoma was examined immunochemically and histochemically, GBG was extracted from colonic carcinoma as a serum-type glycoprotein of 160 kilodaltons. GBG was not identical with carcinoembryonic antigen (CEA), since its molecular weight and localization in tissue sections were different from those of CEA. The non-reducing terminals of GBG probably carry N-acetylglucosamine, but not blood group determinants. Furthermore, GBG was released by phosphatidylinositol-specific phospholipase C from cell membrane. GBG was suggested to be anchored to the membrane via linkage to a glycosyl-phosphatidylinositol molecule. Among colonic carcinoma-associated antigens, serum-type glycoproteins having N-acetylglucosamine at non-reducing terminals have not previously been reported. GBG is a novel carbohydrate antigen of human colonic carcinoma.

Adult↗
PubMed1985

[A case of leiomyosarcoma of the rectum with widespread lymph node metastases].

A case of leiomyosarcoma of is reported. A 78-year-old man was admitted with a history of constipation and deformation of the stools. Barium contrast study and sigmoidoscopy showed a submucosal tumor of the rectum. On computed tomography and angiography, the tumor was suspected of being leiomyosarcoma. Abdominoperineal resection was performed. Microscopic examination revealed a leiomyosarcoma of the rectum and widespread lymph node metastases were found. Leiomyosarcoma of the rectum is an uncommon tumor. In our country, 89 cases have been reported. Six had lymph node metastases initially and another six subsequently. We have referred to the literature on leiomyosarcoma of the rectum.

Aged↗