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Biomedical subjects

Y Sato

Publications and source records attributed to Y Sato.

At least 487 records · Page 27Linked to original sources
PubMed2000

Vitamin E supplementation attenuates leakage of enzymes following 6 successive days of running training.

The purpose of this study was to examine whether vitamin E supplementation in humans would attenuate an increase of serum enzymes as an indirect marker of muscle damage following a sudden large increase in the running distance in a 6-day running training or not. A randomized and placebo-controlled study was carried out on fourteen male runners who were supplied vitamin E (alpha-tocopherol 1200 IU x day(-1); E) or placebo (P) 4 weeks prior to (T1) and during 6 successive days of running training (48.3 +/- 5.7 km x day(-1), means +/- SD). Resting venous blood samples were obtained before maximal treadmill running, at T1, the day immediately before (T2), the next day (T3), and three weeks (T4) after the running training. Serum levels of alpha-tocopherol, lipid peroxidation products (thiobarbituric acid; TBA), creatine kinase (CK), lactate dehydrogenase (LDH), and LDH isozyme 1-5 were quantitatively analyzed. No significant difference was found in maximal oxygen uptake (VO2max) and maximal heart rates following the exhaustive exercise between the P and E group during the experiments. Vitamin E supplementation significantly increased serum alpha-tocopherol (p<0.001) and decreased TBA levels (p < 0.001) compared with pre-supplementation levels. Although serum CK and LDH activities increased significantly at T3 in either group, significantly lower CK (p < 0.05) and LDH (p < 0.001) levels were observed in the E group compared with the P group. The ratio of LDH1 to LDH2 (LDH1/LDH2) decreased significantly at T3 in either group compared with the T1 levels, since there was no significant difference in the LDH1/LDH2 between the P and E group throughout the experiments. These results indicate that vitamin E supplementation can reduce the leakage of CK and LDH following 6 successive days of endurance running. The protective effect of vitamin E against free radicals probably inhibits free-radical-induced muscle damage caused by a sudden large increase in the running distance.

Adult↗
PubMed2000

Adherence of cyanoacrylate which leaked from gastric varices to the left renal vein during endoscopic injection sclerotherapy: a histopathologic study.

We report a case involving leakage of cyanoacrylate (CA) to the inferior vena cava (IVC) through a gastrorenal shunt and left renal vein. A 72-year-old man with liver cirrhosis was admitted to our hospital to undergo emergency treatment for massive hemorrhage of gastric varices. Endoscopic injection sclerotherapy (EIS) using CA was performed on the varices. Radiographic fluoroscopy revealed that most of the injected CA had adhered firmly to the gastric varices, but a certain portion of the CA had flowed to the IVC through the gastrorenal shunt and left renal vein. At that point, the patient did not complain of any symptoms. However, 6 months later, he died of hepatic failure and an autopsy was performed. Histopathologic examination of the wall of the IVC and renal vein, to which CA had adhered, revealed that the CA was covered with endothelial cells of the vessel and no nearby thrombus was present. Long-term anticoagulant therapy may not be indicated in cases of leakage of CA from the gastric varices to other veins, since the leaked CA may be readily covered with endothelium without thrombus formation as in our patient. It is possible for CA to flow to the IVC and have a fatal impact. Our patient was fortunate, and for safe EIS it is important that these complications are prevented.

Aged↗
PubMed2000

Nitric oxide decreases insulin resistance induced by high-fructose feeding.

The effect of nitric oxide (NO) on insulin resistance was studied in high-fructose-fed rats. A sequential hyperinsulinemic euglycemic clamp procedure was employed (insulin infusion rates: 3 and 30 mU/kg BW/min) in 12 high-fructose-fed rats and 12 chow-fed rats while awake. Half of the high-fructose-fed and the chow-fed rats, respectively, were continuously given sodium nitroprusside (SNP, 3 ng/kg BW/min) during the clamp study. Blood glucose was clamped at the fasting level in each rat. Plasma insulin levels during the 3 and 30 mU/kg BW/min insulin infusions were 30 and 400 microU/ml, respectively. Metabolic clearance rate of glucose (MCR) was regarded as an index of whole body insulin action. At both 3 and 30 mU/kg BW/min insulin infusions, high-fructose feeding showed a significant decrease in MCR compared with the chow-fed rats. However, decreased MCRs were stimulated by SNP administration and reached similar levels as the chow-fed rats. SNP infusion did not influence MCRs in the chow-fed rats. Therefore it could be concluded that NO can improve insulin resistance induced by high-fructose feeding.

Animals↗
PubMed2000

Walking at moderate speed with heel-less shoes increases calf blood flow.

This study was designed to examine the physiological and biochemical effects of wearing heel-less shoes over a wide range of walking speeds. Six male students wearing alternately regular shoes and heel-less shoes walked at the constant speeds of 60, 80, 100 and 120 m/min for 10 min on a treadmill at 0% grade. The average heart rate was higher during heel-less shoe trials than when subjects walked in regular shoes at each speed, but differences were not significant. The calf blood flow showed its highest mean value at 80 m/min when subjects walked in heel-less shoes, and at 100 m/min when they walked in regular shoes. However, at walking speeds higher than these, calf blood flow decreased for wearers of both types of shoes. The calf blood flow after 80 m/min was higher when walking in heel-less rather than regular shoes. Blood lactate concentration after walking in heel-less shoes at 120 m/min was significantly higher than basal level, but after walking in regular shoes it was unchanged from the level before walking. Noradrenaline concentration at 120 m/min while walking in heel-less shoes was significantly higher than while walking in regular shoes. In conclusion, walking exercise in heel-less shoes induced an increase of the calf blood flow at a moderate speed, and increased glycogen metabolism and noradrenaline secretion at a faster speed.

Adult↗
PubMed2000

Diabetes and life-styles: role of physical exercise for primary prevention.

Regular physical exercise has been known to be beneficial in the treatment of type 2 diabetes. Epidemiological studies of physical exercise: previous non-randomized studies suggested that a life-style intervention program involving diet and/or exercise reduced the progression of impaired glucose tolerance (IGT) to type 2 diabetes. Recent randomized controlled intervention trials also showed that diet and/or exercise intervention led to a significant decrease in the incidence of diabetes among those with IGT. Endocrinological and metabolic effects of exercise: in well controlled diabetic patients, physical exercise promotes utilization of blood glucose and lowers blood glucose levels. On the other hand, in poorly controlled diabetic patients with ketosis, physical exercise results in further rises in blood glucose, free fatty acids and ketone body concentrations. Long-term gentle regular jogging increases insulin action in respect of both carbohydrate and lipid metabolism despite no influence on body mass index or maximal oxygen uptake. A significant correlation was observed between deltaMCR (insulin sensitivity) and average daily steps Our recent data suggested that the improvement of insulin action by physical exercise was attributed, at least in part, to the increase in insulin-sensitive GLUT4 (glucose transporter 4) on the plasma membrane in skeletal muscle. In conclusion, as an adjunct to other forms of therapy, mild regular physical exercise will play an important role in primarily preventing type 2 diabetes.

Adult↗
PubMed2000

Ultrasonic surgical system (SONOPET) for microsurgical removal of brain tumors.

We use the ultrasonic surgical system in the treatment of brain tumors such as meningioma, neurinoma, glioma, etc. SONOPET is a useful and safe ultrasonic surgical system for microsurgery. The outer diameter of the tip of ultrasonic surgical systems is usually 2.5 mm and the inner diameter 2.0 mm. However, the outer diameter of the SONOPET is 1.9 mm and the inner diameter 1.5 mm. Even in a deep site, because of the small diameter tip, the operation can be done easily. Further, the very thin outer diameter of the tip flue, 5 mm, makes it easy to operate in the deep site. The maximum amplitude of the distal end tip, which can be an important factor in tissue fragmentation, is 240 microns. It is said that the thinner tip breaks down easily, but by reducing metal fatigue the lifetime of the tip is longer and a larger amplitude can be obtained. As a result, hard tissue fragmentation becomes available even with a thinner tip. The handpiece is very light in weight, approximately 110 g, helping to reduce operator fatigue when in long term use. The weight is approximately one-half of conventional types. Because of the high efficiency of the electricity/vibration energy conversion rate, the handpiece does not heat up during the operation. Also, since water cooling is not necessary, the procedures before and after use are simple. Changing the handpiece during the operation is also easy.

Brain Neoplasms↗
PubMed2000

Extracellular superoxide dismutase in tissues from obese (ob/ob) mice.

We have examined the protein content and gene expression of three superoxide dismutase (SOD) isoenzymes in eight tissues from obese ob/ob mice, particularly placing the focus on extracellular-SOD (EC-SOD) in the white adipose tissue (WAT). Obesity significantly increased EC-SOD level in liver, kidney, testis, gastrocnemius muscle, WAT, brown adipose tissue (BAT), and plasma, but significantly decreased the isoenzyme level in lung. Tumor necrosis factor-alpha and interleukin-1beta contents in WAT were significantly higher in obese mice than in lean control mice. Immunohistochemically, both WAT and BAT from obese mice could be stained deeply with anti-mouse EC-SOD antibody compared with those from lean mice. Each primary culture per se almost time-dependently enhanced EC-SOD production, and overtly expressed its mRNA. The loss of heparin-binding affinity of EC-SOD type C with high affinity for heparin occurred in kidney of obese mice. These results suggest that the physiological importance of this SOD isoenzyme in WAT may be a compensatory adaptation to oxidative stress.

Adipose Tissue↗
PubMed2000

Sensitive thyroid-stimulating antibody assay in whole serum containing five percent polyethylene glycol using porcine thyroid cells.

Previously we reported that the amounts of cyclic adenosine monophosphate (cAMP) production by polyethylene glycol (PEG) 22.5% precipitated fraction (PF) (crude immunoglobulin G [IgG]) from thyroid-stimulating antibody (TSAb)-positive serum were higher than those by PEG 12.5% PF, and that PEG (5%) augmented affinity purified TSAb-IgG-stimulated cAMP production in porcine thyroid cells (PTC) assay. In the present work, we studied sensitive TSAb assay using whole sera in the presence of high PEG concentrations in PTC assay. cAMP produced by TSAb-positive serum increased in proportion to serum amounts up to 0.05 mL, but gradually decreased in 0.075 mL. The maximal augmentative effect of PEG on TSAb-positive serum (0.05 mL)-stimulated cAMP production was found in 5% PEG (final). Thus, TSAb assay using whole serum (0.05 mL) in the absence of 5% PEG (serum method) and sensitive TSAb (sTSAb) assay using whole serum (0.05 mL) in the presence of 5% PEG (serum plus 5% PEG method) were performed. The sensitive thyroid-stimulating antibody (sTSAb) activities of Graves' sera showed significantly higher (twofold to sevenfold) compared to simple TSAb activity with sera. sTSAb and TSAb activities were positive in 91% (29/32) and 47% (15/32) of untreated Graves' patients with hyperthyroidism. The sTSAb activities by serum plus 5% PEG method were higher than that by PEG 12.5% precipitated fraction (PF) from test serum (0.2 mL) in many Graves' sera, but lower than that by PEG 22.5% PF from test serum (0.2 mL). PEG (5%) did not augment cAMP produced by high TSH serum (127-210 mU/L) in thyroiditis chronica. sTSAb activity was negative in adenomatous goiter, subacute thyroiditis, and thyroid cancer. sTSAb activity was also negative in TSH stimulation blocking antibody (TSBAb)-positive hypothyroidism (during thyroxine [T4] treatment), but was positive in Graves' sera with coexistence serum of TSAb and TSBAb because of augmentative effect of 5% PEG on TSAb activity. This assay in whole serum (0.05 mL) containing 5% PEG is less sensitive than sensitive TSAb assay using PEG 22.5% PF from test serum (0.2 mL), but this method can be available clinically as routine TSAb assay using whole serum because of the technical simplicity.

Animals↗
PubMed2000

Remission of Graves' hyperthyroidism predicted by smooth decreases of thyroid-stimulating antibody and thyrotropin-binding inhibitor immunoglobulin during antithyroid drug treatment.

It is important to know whether a patient with Graves' disease will get into remission or not during antithyroid drug (ATD) treatment. Thyrotropin (TSH) receptor antibodies (TRAb) cause Graves' disease. Thyroid-stimulating antibody (TSAb) and TSH-binding inhibitor immunoglobulin (TBII) have been measured as TRAb to diagnose Graves' disease and to follow Graves' patients. Smooth decreases of TSAb and TBII during ATD treatment predict the remission of Graves' hyperthyroidism. We followed serial changes of TSAb and TBII in 58 Graves' patients before, during, and after ATD treatment; TSAb was measured as a stimulator assay, using porcine thyroid cells, and TBII as a receptor assay. Patterns of TSAb and TBII changes during ATD treatment differ from one patient to another. TSAb and TBII activities decreased and disappeared in 52 (group A) but continued to be high in the other 6 (group B); 39 of the 52 group A patients achieved remission, but all of the 6 group B patients with persistently positive TSAb and TBII continued to have hyperthyroidism. No differences in the initial TSAb and TBII activities were noted between the 52 group A patients and the 6 group B patients. Of the 52 group A patients in whom TSAb and TBII had disappeared, 44 had smooth decreases of TSAb and TBII (group A1), and 8 had complex changes of TSAb and/or TBII (group A2); 36 of the 44 group A1 patients (82%) but only 3 of the 8 group A2 patients (37%) continued to be in remission more than 1 year after ATD discontinuation. The number of remission in group A1 was significantly larger than that in group A2. No differences in the initial TSAb and TBII activities were noted between group A1 and group A2. More than 80% of group A1 patients, who had smooth decreases of TSAb and TBII, continued to be in remission longer than 1 year. We demonstrated that smooth decreases of TSAb and TBII during ATD treatment predicted the remission of Graves' hyperthyroidism. The Graves' patients can be classified into A1, A2, and B groups according to the patterns of TSAb and TBII changes during ATD treatment. Group A1 patients, who had smooth decreases of TSAb and TBII, had higher rate of remission than the others. Smooth decreases of TSAb and TBII during the early phase of ATD treatment are a reliable predictor of the remission.

Adult↗
PubMed2000

In vivo trafficking and catabolism of IgG1 antibodies with Fc associated carbohydrates of differing structure.

We have now produced mouse-human chimeric IgG1 in wild-type Chinese hamster ovary (CHO) cell lines Pro-5 as well as in the glycosylation mutants Lec 2, Lec 8, and Lec 1. Analysis of the attached carbohydrates shows those present on IgG1-Lec 1 were mannose terminated. Carbohydrate present on IgG1-Lec8 was uniformly biantennary terminating in N-acetylglucosamine. The glycosylation profiles of IgG1-Lec 2 and IgG1-Pro-5 were heterogeneous. Only IgG1-Pro-5 was sialylated with sialic acid present on only a small percentage of the carbohydrate structures. When the in vivo fate of antibodies labeled with (125)I-lactotyramine was determined, it was found that the majority of all of the antibodies, irrespective of the structure of their attached carbohydrate, is catabolized in the skin and muscle. However, the attached carbohydrate structure does influence the amount that is catabolized in the liver and the liver serves as a major site for the catabolism of proteins bearing carbohydrate with the Lec2 (with terminal galactose) or Lec1(with terminal mannose) structure.

Animals↗
PubMed2000

Relationship between intraocular pressure and obesity in Japan.

BACKGROUND: Some cross-sectional studies have suggested that age, systolic blood pressure and obesity are positively related to intraocular pressure (IOP), but few longitudinal studies have examined this relationship. This study was carried out to evaluate the association between intraocular pressure and obesity by cross-sectional and longitudinal analyses in a large Japanese population. METHODS: Data were collected from annual health examinations between 1989 and 1997 and reviewed retrospectively. Subjects of the cross-sectional analysis were 70 139 males and females aged 14-94 years. Among these subjects, 25 216 males and females who had undergone IOP measurements more than three times were analysed longitudinally. The association between IOP and obesity was examined cross-sectionally and longitudinally. RESULTS: Cross-sectional analysis: The mean IOP at the last visit was 11.6 mmHg. The IOP decreased gradually with age and was significantly higher in males than in females in almost all age groups. Body mass index (BMI) significantly correlated with IOP after controlling for age, gender and blood pressure. Longitudinal analysis: There was a significant association between longitudinal change in IOP and change in weight. This relationship remained significant after controlling for initial BMI, initial blood pressure, change in blood pressure, gender and age. CONCLUSION: This study showed a significant association between IOP and obesity in both cross-sectional and longitudinal analysis. These findings suggest that obesity is an independent risk factor for increase in IOP.

Adolescent↗
PubMed2000

In vitro and in vivo antibacterial activities of a new injectable carbapenem, S-4661, against gynaecological pathogens.

Carbapenems are often used to treat infections in obstetrics and gynaecology because of their activity against anaerobes. S-4661, a new injectable carbapenem antibiotic, has favourable pharmacokinetic properties and is not hydrolysed by dehydropeptidase I. We investigated the in vitro and in vivo antibacterial activities of S-4661 against strains of Streptococcus agalactiae, Escherichia coli, Peptostreptococcus magnus, Bacteroides fragilis and Prevotella bivia, which are major pathogens in the fields of obstetrics and gynaecology. The MIC(50) and MIC(90) of S-4661 for these strains were 0.25 and 1 mg/L, respectively. The in vivo efficacy of S-4661 was evaluated in a rat model of intrauterine infection, namely pyometra caused by E. coli and B. fragilis. The accumulation of neutrophils in the uterus in the S-4661-treated group was less marked and the number of bacteria significantly lower than those in the untreated group. These results suggest that S-4661 may be useful for treating polymicrobial infections in the fields of obstetrics and gynaecology.

Animals↗
PubMed2000

In vitro antifungal activity of FK463, a new water-soluble echinocandin-like lipopeptide.

The antifungal activity of FK463 against 72 recent clinical isolates of Candida albicans (24), Candida glabrata (17), Candida tropicalis (11), Candida krusei (8) and Candida parapsilosis (12) was compared with those of amphotericin B, fluconazole and itraconazole by means of a broth microdilution method specified by the National Committee for Clinical Laboratory Standards (NCCLS) document M27-A. The lowest drug concentration at which 90% of the population was inhibited (MIC(90)) of FK463 against C. albicans, C. glabrata, C. tropicalis, C. krusei and C. parapsilosis was 0.0156, 0. 0156, 0.0313, 0.125 and 1 mg/L, respectively. FK463 exhibited broad-spectrum activity against clinically important Candida spp. (MIC range < or =0.0039-2 mg/L), and its MICs for such fungi were lower than those of other antifungal agents tested. The minimum fungicidal concentrations for Candida spp. did not differ by more than two-fold from the MICs. Results from pre-clinical evaluations performed to date indicate that FK463 should be a potent parenteral antifungal agent.

Antifungal Agents↗