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S Yoshimoto

Publications and source records attributed to S Yoshimoto.

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

Parabolic flight experiments on physiological data acquisition and processing technologies using small jet aircraft (MU300).

The parabolic aircraft flight provides a short low gravity environment for approximately 20 seconds, which may not be sufficient for a research on the physiological phenomenon induced by actual weightlessness in space. However, the method is still useful to reveal essential and characteristic feature of physiological signs, and is available for testing hardware and also training of crew member during altered gravity. This paper reports the summary of parabolic flight experiments recently conducted as a NASDA program (1990-1992). The program is providing opportunities in low gravity research with small jet aircraft for researchers and agencies. The flight experiments in the life science area have been conducted mostly focused on a physiological changes and basic methodology which may be effective under the altered gravity condition. In this study, the following research team, NASDA, Research Institute of Environmental Medicine, Nagoya University, Toyohashi University of Technology, Tokyo Metropolitan Hospital, Torey Research Center and JSUP were involved and coordinated for the research.

Aircraft↗
PubMed1994

[Effects of ethanol on isometric tonus of guinea pig gall bladder strips].

Using gall bladder strips isolated from guinea pigs, effects of ethanol treatment in vitro and in vivo on gall bladder tonus were studied. In the control (glucose administrated) group, the reactivity and sensitivity of ACh contraction of the strips were attenuated by ethanol at the concentration of 200 mM and over, while those of CCK contraction was attenuated at the concentration of 200 mM over. On the other hand, in the strips from guinea pigs chronically administered 3% ethanol, both ACh- and CCK-induced contractions were inhibited by the ethanol at the concentrations of 200 mM over. It is known that CCK and ACh are main humoral factors in situ which influence gall bladder tone, and physiologically attainable concentrations of ethanol are below 100 mM. Therefore, it is concluded that the physiological concentrations of ethanol unlikely affect the motility of gall bladder in vivo.

Animals↗
PubMed1994

[Relationships between serum vitamin-A and subjective health, blood and urinary biochemical parameters, dietary intake and food preferences in students].

Students, 60 females (mean age of 19 years) and 54 male (mean age of 23.8 years), were studied for relationships between serum vitamin A concentration (V-A level) and subjective health (by CMI method), birth order, blood and urinary parameters, dietary intake and food preferences. V-A level for females was significantly lower than for males. V-A level significantly and positively correlated to the parameters of hepatic enzymes (gamma-GTP, GOT, GPT), lipid (T-chol, TG) and urinary Na/K. The V-A level showed independent significant correlation to gamma-GTP in multiple regression analysis. V-A level of those born second in birth order showed a tendency to be lower than those first and third in birth order. In females, subjects without subjective CMI complaints had higher level of V-A than those with complaints. This tendency was not seen in males except for items related to the respiratory system. V-A level showed an apparent increase corresponding to daily intake of soybean and vegetables in females, and with amounts of drinking or smoking in male. In males, V-A levels showed a significant positive correlation to serum oxygen peroxide measured by malondialdehyde and did not show an anti-peroxidation effect. In addition positive correlation to total cholesterol was observed in males.

Adult↗
PubMed1993

Effects of ethanol on contractile response of gall bladder isolated from guinea pig.

The effects of ethanol treatment in vitro and in vivo on gall bladder contraction were investigated using gall bladder strips isolated from guinea pigs. In vitro pretreatment of the strips with ethanol at a concentration of over 50 mM significantly attenuated the reactivity and sensitivity of contractile responses to KCl, acetylcholine and histamine in a concentration-dependent manner. Indomethacin treatment or removal of extracellular calcium remarkably reduced gall bladder contractile response to acetylcholine. The depressive effect of ethanol in vitro on gall bladder contraction was also noted in the presence of indomethacin or absence of calcium in the medium. The concentration-response curve of calcium-induced contraction in 40 mM KCl-depolarized gall bladder strip shifted to the right on pretreatment with ethanol. In the case of strips following the chronic administration of 3% ethanol solution ad libitum for 4 weeks, contractile responses to KCl, acetylcholine and histamine did not differ, compared to those in the pair-fed group. This chronic ethanol administration induced tolerance to the acute inhibitory effect of ethanol on gall bladder contractile responses to the agonists. Ethanol is thus shown to exert direct inhibitory action on gall bladder contraction by lowering the calcium sensitivity of the contractile apparatus of smooth muscle; it is unlikely that ethanol consumption would affect gall bladder motility in vivo, owing to the tolerance produced toward the acute inhibitory action of ethanol.

Acetylcholine↗
PubMed1993

Effect of diethyldithiocarbamate on diabetogenic action of alloxan in rats.

To determine whether alloxan action is mediated by hydroxyl radicals in vivo, we assayed methane sulfinic acid (MSA), a product of the trapping reaction of dimethyl sulfoxide (DMSO) with hydroxyl radicals. In DMSO-treated rats, the plasma levels of MSA were increased after injection of alloxan (75 mg/kg). This supports the hypothesis that the diabetogenic action of alloxan is mediated by hydroxyl radicals in vivo. The role of cytosolic superoxide dismutase (SOD) in protecting B cells against chemically induced diabetes was studied in rats injected intraperitoneally with diethyldithiocarbamate (DDC). When rats were injected intraperitoneally with DDC (750 mg/kg), the SOD activity at 2.5 h was decreased by 44% in the whole pancreas. The decreased SOD activity was affected by DDC but not by alloxan. Intraperitoneal injection of rats with DDC (750 mg/kg) increased diabetogenic susceptibility to a nondiabetogenic dose of alloxan (20 mg/kg). Subcutaneous injection of vitamin E, prior to administration of both DDC and alloxan, provided partial protection to the rats against the diabetogenic action. These findings suggest that the susceptibility to diabetogenic action of alloxan in B cells is augmented when the cellular SOD activity is inhibited. Thus, cellular SOD may play an important role in the maintenance of B cell function.

Alloxan↗
PubMed1993

Role of metallothionein in 4-aminopyrazolo[3,4-d]pyrimidine-administered mouse pancreas.

Pancreatic metallothionein (MT) and zinc levels were measured after the administration of 4-aminopyrazolo(3,4-d)pyrimidine (4APP) to mice to determine the role of pancreatic MT. 4APP was found to increase the pancreatic MT level dose-dependently; the pancreatic MT level in mice administered 175 mg/kg of 4APP was 3.9 fold higher than that in control mice. When 40 mg/kg or less of 4APP was administered, the zinc concentration of the pancreatic cytosol fraction did not differ from that in control mice, while after 175 mg/kg of 4APP it was 1.7-fold higher. There was no difference in plasma glucose and insulin levels between the controls and mice administered 175 mg/kg of 4APP, although the plasma alpha-amylase activity was reduced in the latter. Moreover, a linear negative relationship was observed between pancreatic MT level and plasma alpha-amylase activity (r = -0.795, p < 0.01). These findings suggest that pancreatic MT is affected by the disruption of the exocrine function in 4APP-administered mouse pancreas.

Adenine↗
PubMed1993

Effect of lower body negative pressure on cerebral circulation.

This experiment was performed to study the effects of lower body negative pressure (LBNP) on cerebral circulation. Cerebral hemodynamics were monitored continuously and noninvasively in eight subjects at 30 mmHg of LBNP for 25 minutes by following items: 1) the carotid Doppler flowmeter which measures the carotid blood flow, 2) the transcranial Doppler sonography which measures the flow velocity of the middle cerebral artery, 3) the near infrared spectrophotometer which measures the oxygenated and deoxygenated hemoglobin in the brain. The mean flow velocity of the middle cerebral artery and the blood flow of the common carotid artery significantly decreased during LBNP, even though the mean arterial blood pressure was well maintained. The oxygenated hemoglobin was significantly increased during LBNP, while the deoxygenated hemoglobin was not changed significantly. Our results suggest that exposure to moderate LBNP (30 mmHg) decreased the cerebral blood flow with the vasodilation on the arterial side of the brain.

Adult↗
PubMed1993

[Effect of ethanol on isometric tone of aorta from guinea pig].

Using aortic strips isolated from guinea pig, effects of ethanol on vascular smooth muscle tone were studied. Low concentrations (5, 50, 100 mM) of ethanol potentiated norepinephrine and serotonin-induced contractions, but not KCl-induced one. Ethanol (100 mM) potentiated calcium-induced contraction in the presence of norepinephrine, but not that in the presence of KCl. Ethanol (100 mM) showed no effects on norepinephrine-induced contraction in the calcium-free medium. Ethanol (100 mM) augmented 45Ca uptake stimulated with norepinephrine, but not that with KCl. Ethanol at the higher concentration of 600 mM by itself induced contraction, which was inhibited by trifluoperazine or in the calcium-free medium, but not by phentolamine, diphenhydramine, methysergide, indomethacin or nifedipine. Ethanol (600 mM) directly increased 45Ca uptake, which was not affected by nifedipine. These findings indicate that the low concentrations of ethanol potentiate receptor-mediated vascular smooth muscle contraction and the higher concentration of ethanol directly contracts it via facilitation of transmembranous calcium influx.

Animals↗
PubMed1993

[Anemia and neutropenia due to copper deficiency during long-term total parenteral nutrition].

A 33 year-old man with undiagnosed neuropathy showing mental retardation and involuntary movements has been nourished for a long period by total parenteral nutrition (TPN) because of frequent vomiting and repeated aspiration pneumonitis. After ten months' TPN, macrocytic anemia and neutropenia developed and iron preparation was administered without hematological improvement. Bone marrow examination revealed normocellular marrow without features of megaloblastosis and dysplasia. In some erythroblasts and immature myeloid cells, vacuoles were observed and mature granulocytes were reduced in the bone marrow. Both serum copper and ceruloplasmin were very low (12 micrograms/dl and 7mg/dl, respectively). Thus, oral administration of copper sulfate resulted in marked increase of reticulocytes and subsequent improvement of anemia and neutropenia within two months. Copper deficiency is a rare condition, but during an unusual nutrition such as TNP, hematological abnormality due to copper deficiency must be noticed to occur.

Administration, Oral↗
PubMed1992

Effect of chromium administration on glucose tolerance in stroke-prone spontaneously hypertensive rats with streptozotocin-induced diabetes.

The present study was conducted to assess the effect of chromium (Cr) administration on glucose tolerance in insulin-dependent diabetes that accompanies hypertension. Four rat groups were used: stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar Kyoto rats (WKY) with and without streptozotocin (SZ, 40 mg/kg)-induced diabetes. Each group of rats was subdivided to the Cr-dose group and the control group. The Cr-dose group, which was intraperitoneally administered Cr solution (20 micrograms trivalent chromium/kg body weight/d for 4 weeks), and the control group (saline) were studied for plasma glucose and plasma insulin during intraperitoneal glucose tolerance test (IPGTT) and insulin action by isolated adipocytes. For diabetic SHRSP showing the highest plasma glucose and lowest plasma insulin among the four groups, Cr administration led to the greatest reduction in plasma glucose without a significant effect on plasma insulin during IPGTT. For each diabetic WKY and normal SHRSP and WKY, those given Cr showed lower levels of plasma glucose with lower levels of plasma insulin than the controls. For diabetic SHRSP, glucose uptake by isolated adipocytes in the Cr-dose group was higher than that in the control group. This effect of Cr administration involved enhancement of insulin responsiveness and sensitivity, attributed to enhanced affinity of the insulin receptor. A similar tendency was observed for diabetic WKY. However, for normal SHRSP and WKY, the increase in glucose uptake due to Cr administration coincided only with enhanced insulin responsiveness.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Decrease in plasma GLP-1 immunoreactivity in starved rats.

To determine whether starvation affects the metabolism of glucagon-like peptide-1 (GLP-1), we measured the plasma levels of proglucagon-derived peptides and the biosynthesis and posttranslational processing of proglucagon in groups of six rats starved for 1, 3 and 5 days. The plasma levels of GLP-1 immunoreactivity (GLP-1 IR) and glucagon-like immunoreactivity (GLI) decreased during starvation reaching 79 and 56% of the respective control values by day 5 (P less than 0.05 and less than 0.01 vs control). The same is true of the plasma IRI level. The ileal contents of GLP-1 IR and GLI were 50.8 +/- 3.8 pmol/g wet weight and 161.8 +/- 13.2 pmol/g wet weight, respectively, on day 5 of starvation, which were significantly lower (P less than 0.01) than the respective values of 94.8 +/- 16.6 pmol/g wet weight and 262.7 +/- 28.1 pmol/g wet weight in control rats. However, the pancreatic contents of proglucagon-derived peptides tended to increase during starvation, although their increases were not statistically significant. No significant change in the posttranslational processing of proglucagon was detected during starvation. The decrease in the ileal proglucagon-derived peptides content was not associated with a decrease in intestinal proglucagon mRNA transcripts. These results suggested that decreased synthesis of proglucagon-derived peptides by the intestine was largely responsible for the reductions in their circulating levels in starved rats.

Analysis of Variance↗
PubMed1992

[A study of factors affecting the concentration of serum lipid peroxide in the elderly inhabitants in a rural area].

Among 16 male (mean age of 66.6 years) and 51 female (mean age of 65.3 years) inhabitants of a rural area, the concentration of serum lipid peroxide measured as malondialdehyde (MDA) by Yagi's method was analyzed by physicochemical and food intake items. The MDA level in serum showed a peak of 6.2 nmol/ml at fifties years old in females and showed constant values of 4.6 and 6.1 nmol/ml for females and males, respectively, in those aged 60 more. The MDA level significantly correlated positively to total- or LDL-cholesterol level and urinary K/Cr, thus MDA level seemed to be a risk factor of arteriosclerosis. Fruit intake significantly positively correlated to MDA level in male. The MDA level showed a significantly higher level in the group with both higher total-cholesterol and urinary K/Cr levels, than in the other groups. It is suggested that a high intake of potassium increases the MDA level in the group with higher total-cholesterol level.

Aged↗
PubMed1992

[Chinese medicine discovered in "Jing Ping Mei"].

Using a novel written in the Ming dynasty and dealing with the time of Zong dynasty, I tried to assess the common medical services available in those days. The name of the novel is "Jing Ping Mei". The book contains many descriptions of sexual acts and had long been listed as an erotic novel, but by studying its contents closely we came to see that the life of the people in olden times is vividly and concisely illustrated. When a person became critically ill, first a doctor was called in, and then the so-called "three nuns and six old women" gave herb drugs or moxa treatments. They sometimes worked as midwives, said prayers, or acted as a shaman. They lived closely with the family of Xi Men Qing. If these women were unsuccessful, taoists came to pray and perform rituals. Finally the diviner or fortune-teller (yin-yang master) made preparations to allow free passage to the other world. Then the date of the funeral, position of the tomb, and the fate of the person were told. These steps are all described in the book. The doctor deals with many departments, such Ren, He, Liu. Bogus doctors such as Hu, and Zhao also appear in the stories. They are generally called bell doctors or wandering doctors. They are regarded as second-class doctors, but they were more popular with the common people and were engaged in medical services. In fact, it seems that they were respected by the townspeople. In some ways, they were associated with taoism. ...

China↗
PubMed1992

[A case of pulmonary atypical mycobacteriosis complicated with aplastic anemia, treated with surgical resection and postoperative sparfloxacin].

A few weeks after treatment with INH, RFP and SM, severe aplastic anemia developed in a 49-year-old man with pulmonary atypical mycobacteriosis due to M. kansasii. All drugs were discontinued immediately after bone marrow examination revealed severely hypoplastic marrow, but pancytopenia continued for several months. Although M. kansasii was sensitive to other drugs including CS and TH, these two drugs were also discontinued because of their respective psychiatric and hepatic adverse effects. Ofloxacin (OFLX), to which M. kansasii was sensitive, was administered without clinical improvement and complete resistance to OFLX developed after several months treatment. Right upper and middle lobectomy and S6 partial lobectomy was performed, and postoperative sparfloxacin (SPFX) administration resulted in cure of the disease. Drug sensitivity testing revealed that the organism had acquired resistance to OFLX, but was still sensitive to SPFX. Thus, SPFX appears to be an useful drug for the treatment of atypical mycobacteriosis.

Anemia, Aplastic↗
PubMed1992

[Secondary sideroblastic anemia caused by long term administration of anti-tuberculous agents including isoniazid].

A 54 year-old man, who had been treated for several years with isoniazid, was transferred to our hospital because of intractable pulmonary tuberculosis. He was given several anti-tuberculous agents including INH, CS and/or PZA for a long period of time without improvement of the pulmonary tuberculosis. After 7 years' treatment with INH, hypochromic microcytic anemia developed. Parenteral administration of iron preparation failed to improve the anemia. The bone marrow findings revealed erythroid hyperplasia and a few erythroblasts showed megaloblastic change. The bone marrow iron staining revealed increased sideroblasts of which 88% were ringed-form. INH was then discontinued and pyridoxal phosphate was administered with rapid complete improvement of the anemia. INH is well known as a causative agent for acquired secondary sideroblastic anemia, however only one case of INH-induced sideroblastic anemia has been reported in Japan. This is the second reported Japanese case of INH-induced secondary sideroblastic anemia, which appears to be a very rare condition because of genetically determined rapid acetylation of INH in Japanese.

Anemia, Sideroblastic↗
PubMed1992

[Post-gastrectomized vitamin B12 deficient anemia with marked leukoerythroblastosis and ringed sideroblasts].

A 77 year-old man, who had received total gastrectomy and splenectomy 11 years ago for gastric cancer was transferred to our hospital because of severe macrocytic anemia. He had been treated with vitamin B1, B2, C and iron preparations for several weeks. Ten days before admission numbness developed in his legs. On physical examination he appeared severely anemic. Laboratory findings revealed severe macrocytic anemia with poikilocytosis, anisocytosis, polychromasia, red cell fragmentation, Howell-Jolly bodies, Cabot rings and marked erythroblastosis (421/100 WBC). Hypersegmented neutrophils and immature granulocytes were also seen in the blood. The bone marrow picture showed marked erythroid hyperplasia, but erythroblasts revealed only slight megaloblastic changes. On bone marrow iron staining all erythroblasts were classified as type III sideroblasts and 15% of them were ringed-form. Serum vitamin B12 was low (44 pg/ml). Methylcobalamin given intramuscularly led to the rapid improvement of all hematological abnormalities including leukoerythroblastosis. Two weeks after vitamin B12 administration, ringed sideroblasts could no longer be detected in the bone marrow. Post-gastrectomy vitamin B12 deficiency anemias combined with erythroblastosis and ringed sideroblasts is a rare condition. Splenectomy is thought to play an important role in the pathogenesis of these conditions.

Aged↗