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Biomedical subjects

S Tsukamoto

Publications and source records attributed to S Tsukamoto.

At least 91 records · Page 5Linked to original sources
PubMed1996

Effects of bezafibrate on ethanol oxidation in rats.

Bezafibrate is used to lower serum lipid levels in humans. Fibrate derivatives induce an enzyme participating in the beta-oxidation by peroxisomes. We gave ethanol (2 g/kg) orally to bezafibrate-treated (300 mg/kg) male rats of the Wistar strain. Blood ethanol levels were remarkably lower and ethanol elimination stood at 432.6 mg/kg/hr (control, 336.6 mg/kg/hr) in the bezafibrate group (p < 0.01). Blood acetate levels were conversely higher in the bezafibrate group. The fatty acid beta-oxidation activity of liver peroxisome in bezafibrate-treated, clofibrate-treated, or gamma-linolenic acid-treated rats for 4 days was assayed. The activity was 5.8-fold higher in rats given bezafibrate, 5.4-fold in the clofibrate (p < 0.01), and 2.0-fold in the gamma-linolenic acid (p < 0.05). Alcohol dehydrogenase and aldehyde dehydrogenase activity of cytosol in the liver was not induced by the hypolipidemic drugs, but aldehyde dehydrogenase activity in the liver homogenate was induced. From foregoing results, bezafibrate induced in the organism beta-oxidation by peroxisomes and increased H2O2 production, which led to augmented ethanol metabolism by catalase.

Acetates↗
PubMed1996

Effects of tea (Camellia sinensis) chemical compounds on ethanol metabolism in ICR mice.

The effects of a green tea (Camellia sinensis) extract on ethanol metabolism in ICR male mice were studied. A crude green tea extract (GTE) and the tea components as (-)-epigallocatechin gallate (EGCg), (-)-epigallocatechin (EGC), and caffeine were administered before the tests. One hour later, the mice were orally given 2g/kg body weight (b.w.) of ethanol (20% ethanol w/v). The results show that the levels in the blood and liver of ethanol and acetaldehyde were lower, and that the levels of acetate and acetone were higher than in the controls orally given 500 mg/kg b.w. of GTE. After the administration of 75 mg/kg b.w. and 225 mg/kg b.w. of EGCg, the acetate and acetone concentrations in the blood and liver were lower than in the controls. The mice given caffeine at the same dose as that in GTE showed almost the same effects as the group treated with GTE. This suggests that EGCg and caffeine, the principal components of GTE, both had an effect on ethanol metabolism.

Acetaldehyde↗
PubMed1996

Aneurysmal bone cyst in a dog.

A one-year-old male mongrel dog was referred to the Veterinary Clinic with a several-week history of lameness and pain of the right front leg. Radiological examination of the right humerus revealed a cystic lesion at the distal end of the bone; the lesion was nodular in a gross appearance. Histologically, the nodular lesion consisted of large areas of haemorrhage and thick fibrous trabeculae mixed with a variably dilated cavernous structure of blood vessels attributed to haemangiosarcoma. Based on these findings, aneurysmal bone cyst secondary to the tumour was diagnosed.

Animals↗
PubMed1996

[Bronchial arterial infusion therapy for lung metastases of urogenital tumors].

Three patients with lung metastases of urogenital tumors were treated by bronchial arterial infusion therapy. Case 1: A 52-year-old man who had multiple lung metastases of right renal cell carcinoma fell into a dyspnea at 5 months after right radical nephrectomy. Though the effects of resection or laser coagulation with bronchoscopy were temporary, two sessions of BAI therapy with radiation improved the symptom of dyspnea for at least 3 months. Case 2: A 53-year-old man who had multiple lung metastases of right renal cell carcinoma was treated with systemic chemotherapy after right radical nephrectomy. Because the systemic chemotherapy showed only minor response, two sessions of BAI therapy were performed. No lung metastasis was detected in radiographs for 2 years after BAI therapy. Case 3: A 69-year-old man who had multiple lung metastases of left ureteral tumor was treated with 3 sessions of systemic chemotherapy. Though the systemic chemotherapy was effective, 2 sessions of BAI therapy with radiation showed a more suppressive effect, and the regrowth was not detected for 7 months after the therapy was performed. We concluded that BAI therapy was an effective therapeutic method not only for cases with no operative indication, but also for cases in which systemic chemotherapy was not effective.

Aged↗
PubMed1996

Effects of bezafibrate on erythrocyte membrane phospholipids in alcohol-treated rats.

Male rats of the Wistar strain were divided 4 groups, and give a liquid diet of control feed, bezafibrate (150 mg/kg), ethanol, and ethanol plus bezafibrate for 5 week. The effect of bezafibrate supplementation on rats fed ethanol was examined in terms of the fatty acid composition of the phospholipids in the erythrocyte membrane. In the phospholipids profiles of erythrocyte membranes, PI was significantly decreased. The decrease in PI caused by bezafibrate appeared to substantially affect the membrane and consequently lead to changes in the membrane anchor. In the fatty acid composition of the PC, C20: 4 was significantly decreased in the group receiving alcohol (p < 0.05) but increased in the groups receiving bezafibrate (p < 0.05). In the fatty acid composition of the PE, C16: 0 was significantly increased in the three groups when compared with the control, and C20: 4 was decreased in the alcohol group (p < 0.05). In the fatty acid of SM and PI, C20: 4 was decreased and C18: 0 increased in the alcohol group. In the PS, C14: 0 was increased in the alcohol group, and decreased in the alcohol plus bezafibrate group (p < 0.01). The levels of arachidonic acid in the total fatty acids that constituted the membrane phospholipids were decreased in the rats given ethanol (p < 0.05). However, arachidonic acid in the group of bezafibrate supplementation on rats fed ethanol were elevated in comparison with the alcohol group (p < 0.05). With decreasing arachidonic acid as a marker of alcohol tissue injury following chronic alcohol intake, the effects of bezafibrate supplementation appear to contribute to membrane fluidity by altering the biochemical flexibility of the membrane.

Alcohol Drinking↗
PubMed1996

Experiences of postcardiotomy assist: pneumatic ventricular assist device or venoarterial bypass with percutaneous cardiopulmonary support.

From October 1982 to the present, 16 patients have been supported by a pneumatic ventricular assist device (VAD). Since April 1990, we have introduced a venoarterial bypass (VAB) with percutaneous cardiopulmonary support (PCPS) system. This PCPS system was used in 12 patients. The long-term survival rate of PCPS cases (41%) was much better than that of VAD cases (19%). The main cause of death in VAD cases was multiple organ failure (MOF). Although VAB was initiated more recently than VAD, the duration on support was longer in the VAD group than in the VAB group. Because of the longer support duration and the presence of many patients with MOF, coagulopathy deteriorated more readily in the VAD group than in the VAB group. In the case of postcardiotomy cardiopulmonary bypass weaning or low-output syndrome (LOS), the VAB with PCPS system should be applied first under intraaortic balloon pumping assist because of its simplicity and low cost. Thereafter, VAD should be applied in cases refractory to VAB support.

Adult↗
PubMed1995

Frequency of D1S80 and HLA DQ alpha alleles in a Chinese population.

Allele frequency distributions for the D1S80 (MCT118) and HLA DQ alpha loci were determined in a Chinese population sample using the polymerase chain reaction (PCR). A total of 25 alleles and 100 phenotypes were observed for D1S80. The frequency of allele 18 was higher than allele 24 only in this Chinese population when compared to other reported populations. A total of 6 alleles and 21 possible phenotypes were observed for HLA DQ alpha. The power of discrimination was 0.97 and 0.93 for D1S80 and HLA DQ alpha, respectively.

Asian People↗
PubMed1995

Synthesis and structure-activity studies of a series of 1-oxa-2,8-diazaspiro[4.5]decan-3-ones and related compounds as M1 muscarinic agonists.

A series of novel 2,8-dialkyl-1-oxa-2,8-diazaspiro[4.5]decan-3-ones and 2,8-dimethyl-1,2,8-triazaspiro[4.5]-decan-3-one (13), related to M1 muscarinic agonists YM796 and RS86, were synthesized by using Michael addition reaction of hydroxyurea or methylhydrazine to alpha, beta-unsaturated esters followed by cyclization reaction. These compounds were assessed for binding affinities for M1 and M2 receptors and in vivo muscarinic activity: namely, amelioration of scopolamine-induced impairment in rat passive avoidance tasks and induction of hypothermia, tremor, and salivation. 2,8-Dimethyl-1-oxa-2,8-diazaspiro[4.5]decan-3-one (6a) exhibited high affinities for both M1 and M2 receptors, showed antiamnesic activity (0.1 mg/kg, s.c.) and induced hypothermia (3 mg/kg, s.c.). In addition, 6a stimulated phosphoinositide hydrolysis in rat hippocampal slices, indicating partial agonistic activity for M1 muscarinic receptors. The alteration of the methyl group at N2 of 6a increased the selectivity in binding affinities for M1 over M2 receptors, but resulted in loss of M1 agonistic activity or antiamnesic activity. Compound 13 exhibited only low affinity for M1 receptors, suggesting that a basic nitrogen atom is not tolerated in M1 receptor binding as a substitute for an oxygen atom or a carbonyl group at the 1-position of 6a or RS86. None of these derivatives exhibited high selectivity for antiamnesic effect over induction of hypothermia compared to YM796.

Animals↗
PubMed1995

Synthesis and structure-activity studies of a series of 1-oxa-8-azaspiro[4.5]decanes as M1 muscarinic agonists.

2,8-Dimethyl-1-oxa-8-azaspiro[4,5]decan-3-one (17), designed by incorporating the tetrahydrofuran ring moiety of muscarone into an 8-azaspiro[4,5]decane skeleton, and related 1-oxa-8-azaspiro[4.5]decanes were synthesized and assessed as M1 muscarinic agonists for the symptomatic treatment of dementia of Alzheimer's type. The compounds were tested for central muscarinic M1 and M2 receptor affinity and in vivo muscarinic activities: namely, amelioration of scopolamine-induced impairment in rat passive avoidance tasks, and induction of hypothermia, tremor, and salivary secretion. Compound 17 exhibited potent muscarinic activities in vitro and in vivo with no selectivity. Systematic modifications of 17 were conducted, and a number of compounds, including the 2-ethyl analogue (18), 3-methylene analogue (29), 3-dithioketal analogues (26, 28), and 3-oxime analogue (37) were found to display preferential affinity for M1 receptors over M2 receptors and, in addition, to exhibit potent antiamnesic activity sufficiently separated from hypothermia-inducing activity, taken as an index of cholinergic side effects, compared with the reference compound RS86 (1). Structure-activity relationships are discussed in comparison with those for muscarone analogues. Of these compounds only two, 2-ethyl-8-methyl-1-oxa-8-azaspiro[4.5]decan-3-one (18) and 2,8-dimethyl-3-methylene-1-oxa-8-azaspiro[4.5]decane (29), stimulated phosphoinositide hydrolysis in rat hippocampal slices, indicating partial agonistic activity for M1 muscarinic receptors. The optical resolution of 18 and 29 was performed. Eudismic ratios of both compounds in binding affinity were low, but M1 agonist activity resided preferentially in the (-)-isomers. The absolute configuration of (-)-29 was determined by X-ray crystal structure analysis to be S, being the same as that of muscarone. Based on the in vivo selectivity, (-)-29 was selected for clinical studies.

Alkanes↗
PubMed1995

[An experiment on drinking using breath alcohol monitor (Alcomed 3010) by an electrochemical method].

A drinking experiment was performed to evaluate the efficiency of a breath alcohol monitor, Alcomed 3010. The ethanol concentrations in blood and breath were determined by gas chromatography, and in particular the breath ethanol concentration was determined with the breath alcohol monitor and by gas chromatography. The results obtained by two methods were compared. Based on the blood and breath ethanol concentrations, the following conclusions were drawn reading the breath alcohol monitor. The monitor has practical merit for determination of the breath ethanol level. It is small, usable anywhere, with little error in determination. In measuring principle, tobacco and acetone did not affected levels with the meter, but methanol, n-propanol and n-butanol affected determinations with the alcohol monitor. The breath (AM)/blood (GC) ethanol ratio was 1:2555. Comparison of the values determined with the alcohol monitor and gas chromatography yielded the equation: y = 0.998 x +/- 0.012 (r = 0.994). When determinations were made on the pure ethanol gas by the meter and gas chromatograph, the equation was: y = 0.974 x +/- 0.021 (r = 0.994). It may be said therefore that the alcohol monitor is both practically and functionally excellent.

Adult↗
PubMed1995

[Arterial oxygen saturation monitoring of sleeping infants by pulse-oximeter--effect of sleeping position on arterial oxygen saturation in infants].

Monitoring of the arterial oxygen saturation (SaO2) in two sleeping infants was reported. They were a couple of female twins and had grown up normally after admission to NICU (Neonatal Intensive Care Unit) for a month. We investigated their SaO2 with the puls-oximeter at the terms between the 2nd and the 10th month. There was no significant difference between SaO2 in prone positions (n = 29) and that in supine positions (n = 30). In the infant with the sniffing conditions, however, SaO2 in prone positions seemed to be slightly lower than that in the healthy conditions. The slightly low SaO2 would give no effects on the healthy infants, but it may cause ALTE (Apparent Life Threatening Event) or death from SIDS (Sudden Infant Death Syndrome) to some infants who are not in good health and/or who are prone to get into ALTEA or SIDS. Especially, in the sniffing condition with hyperthermia, as the oxygen dissociation curve sifts to right and SaO2 degradation appears easily, sudden infant death may be possible to happen in prone position.

Blood Gas Analysis↗
PubMed1995

Bilateral common iliac artery aneurysms secondary to fibromuscular dysplasia accompanied with a coronary aneurysm. A case report.

Fibromuscular dysplasia (FMD) is found in various arteries but the common iliac arteries and the coronary arteries are seldom involved. A 49-year-old woman was referred to our hospital with a pulsatile mass in her right lower quadrant. She had subdural hemorrhage in a postpartum state at the age of 27. After admission angiography diagnosed the bilateral iliac artery aneurysms and coronary angiography revealed a coronary artery aneurysm, the size of which was 12 mm x 19 mm in the region of the left main trunk. The bilateral iliac artery aneurysms were resected and Y-shaped vascular prosthesis was replaced. Microscopic sections of the aneurysm showed remarkable decrease of elastic fibers and thinning of the media, but no increase occurred in the smooth muscle. Histopathological diagnosis was FMD (periarterial fibroplasia). To our knowledge, no patient with a iliac arterial aneurysm caused by FMD has been reported and only a few cases with coronary arterial FMD have been described. This is the first report of iliac arterial aneurysm due to FMD. Since this case has multiple aneurysms, a long-term follow-up is definitely required, especially focusing on the coronary aneurysm.

Aneurysm↗
PubMed1994

Characterization of a novel muscarinic receptor agonist, YM796: comparison with cholinesterase inhibitors in in vivo pharmacological studies.

Previous reports have shown that (+/-)-YM796 (2,8-dimethyl-3-methylene-1-oxa-8-azaspiro[4.5]decane) exhibits M1 agonistic activity and ameliorates cognitive impairment, and that the (-)-S isomer is active in in vitro studies. We report here the characterization of the (-)-S isomer, YM796 ((-)-(S)-2,8-dimethyl-3-methylene-1-oxa-8-azaspiro[4.5]decane L-tartrate monohydrate), and its (+)-R isomer in in vivo pharmacological studies in comparison with the cholinesterase inhibitors tacrine, amiridine and E-2020. YM796 (0.031-0.5 mg/kg p.o.), like the racemate, reversed the cognitive impairment in passive avoidance tasks of rats with nucleus basalis magnocellularis lesions, whereas (+)-R-YM796 was ineffective in this experimental amnesia. YM796 exhibited only weak effects on mouse salivation and hypothermia, a peripheral cholinergic response and a central cholinergic response, respectively. The (+)-R isomer, however, failed to induce these cholinergic responses. YM796 also ameliorated the memory deficits induced by scopolamine in rats and electroconvulsive shock in mice. The potency of YM796 in these experimental amnesia models was over a 100 times greater than that of tacrine, over 10 times greater than that of E-2020, and 6 times greater than that of amiridine. In salivary secretion and hypothermia, YM796 was 2-4 times weaker than tacrine and E-2020, and 1-2 times stronger than amiridine. Thus, YM796's ratio of anti-amnesic effects to salivary secretion and hypothermia was much greater than that of the cholinesterase inhibitors tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗