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Biomedical subjects

N Takeuchi

Publications and source records attributed to N Takeuchi.

At least 307 records · Page 17Linked to original sources
PubMed1982

Endurance training regimen based upon arterial blood lactate: effects on anaerobic threshold.

The purpose of this investigation was to assess the effect of endurance training based upon the intensity as determined by the arterial blood lactate concentration (LA). Seven healthy male college students performed endurance training on a Monark bicycle ergometer for 15 min on 3 days/week for 8 weeks, at an intensity corresponding to 4 mmol X l-1 arterial blood LA determined during an incremental exercise test (25 watts increment every minute on a bicycle at 50 rpm). Another six male students served as the control group. To assess the training effect, both an incremental exercise test and a submaximal exercise test were performed before and after the endurance training. In the incremental exercise test, VO2max, VE at VO2max, anaerobic threshold (AT), and the onset of respiratory compensation for metabolic acidosis (RCMA) were measured. AT was determined as the point at which arterial LA rose above the resting value, and RCMA was determined as the point at which Paco2 decreased during the incremental exercise test. After training, AT increased significantly (37% increment expressed in VO2, p less than 0.05). There was a significant increase (p less than 0.05) in RCMA (17%) and VO2max (14%). This training decreased VO2 (4%), VE (15%), heart rate (10%), respiratory exchange ratio (5%), and LA (23%) significantly (p less than 0.05) during the submaximal exercise test after training. On the other hand, there were no significant changes in the control group through the period when the training group performed their training. These results showed that the endurance training intensity corresponding to 4 mmol X l-1 arterial blood LA was effective for the improvement in AT as well as VO2max. It is suggested that the present training regimen could delay the onset of anaerobic glycolysis, thus shifting AT to the higher workload and decreasing LA at a given submaximal exercise after training.

Adult↗
PubMed1982

Effect of clinofibrate, a new hypolipidemic agent, on biliary and serum lipids in patients with hyperlipidemia.

Clinofibrate was given to 15 patients with hyperlipidemia, for 6-8 weeks at the daily dose of 600 mg, and its effect on 3 biliary lipid components (cholesterol, bile acids and phospholipids) and on the lithogenic index was investigated. After clinofibrate treatment, 6 of the patients were given 1.5 g/day clofibrate for 6-8 weeks to compare the effect of clofibrate with that of clinofibrate. The molar percentages of biliary cholesterol and phospholipids to the total mol number of the 3 biliary lipid components decreased, and that of bile acids increased during clinofibrate administration. In this way, the molar ratio of bile acids to cholesterol increased during the treatment. Neither the lithogenic index calculated by the formula of Admirand and Small nor that of Hegardt, Dam and Holzbach was altered significantly by the treatment. There was no apparent relationship between the effect of the drug on the lithogenic index and any of the factors initial lithogenic index, rate of decrease of serum lipids, or type of hyperlipidemia. Although clofibrate had no significant effect on the maximum solubility of cholesterol in the bile, the molar percentage of biliary cholesterol was elevated and the lithogenic index increased as compared with the control and clinofibrate period. No significant influence on bile acid composition in the bile was observed, with either clinofibrate or clofibrate.

Adult↗
PubMed1982

Age-related changes in cholesterol and bile-acid metabolism in spontaneously hypertensive rats.

Age-related changes in serum and liver cholesterol, phospholipid and triglyceride levels, serum lipoproteins, biliary secretion of cholesterol, phospholipids and bile acids, fecal excretion of sterols and bile acids, and the pool size of bile acids were examined in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKR). SHR showed distinct age- and sex-related changes when young and marked aged-rat hypercholesterolemia after 1 yr of age. (1) Cholesterol shifted from blood to the liver between 10 and 20 wk only in male SHR and not at all in WKR. (2) Serum lipoprotein percentages changes; alpha-lipoprotein decreased, pre-beta-lipoprotein increased, but beta-lipoprotein did not change. These changes appeared only in male SHR and after 13 to 15 wk of age. (3) Liver enlargement in SHR, although not detected at 5 to 6 wk, progressed more rapidly than in WKR, giving values almost double those in WKR after 13 to 15 wk. Liver enlargement in female SHR was much less than in the male. (4) Bile flow, biliary secretion, and the pool size of bile acids increased. However, when expressed on the basis of liver weight, these values were similar to those in WKR, suggesting that the increases were caused by the hepatomegaly. (5) Differences appeared in the bile acid composition. A large amount of beta-muricholic acid was present in SHR of both sexes and the cholic acid percentage was low in male SHR. (6) Changes were observed in fecal bile acid excretion. Since the daily amounts in male SHR were similar to those in WKR, the hepatic synthesis activity (mg per day per 10 g liver) in male SHR was almost half that in WKR at all ages.

Aging↗
PubMed1982

[Antibacterial activities of cefotiam against various pathogens isolated from clinical materials (author's transl)].

Bacteriological evaluation was made on cefotiam (CTM), a new broad-spectrum cephalosporin antibiotic, and the following results wer obtained. 1) CTM has shown very potent antibacterial activities against Staphylococcus aureus, Escherichia coli, Edwardsiella tarda, Citrobacter intermedius, Salmonella, Klebsiella, Proteus mirabilis, Proteus rettgeri, Proteus inconstans, Yersinia enterocolitica, Aeromonas hydrophila, Plesiomonas shigelloides and Pseudomonas putrefaciens. 2) Streptococcus faecalis, Enterobacter and Proteus morganii isolated from urine, Serratia and glucose non fermentative Gram-negative bacilli except Pseudomonas putrefaciens, were almost insusceptible to cefotiam.

Bacteria↗
PubMed1981

The validity of anaerobic threshold determination by a Douglas bag method compared with arterial blood lactate concentration.

Using an open circuit system (Douglas bag method), measurement of the anaerobic threshold (AT) was performed on ten healthy male college students during an incremental exercise test on a bicycle ergometer in an attempt to determine the validity of this method as compared with arterial blood lactate AT measurement. Blood samples were taken from either the radial or brachial artery through a Teflon catheter (3 ml/each time) every minute until the subject's maximal exercise tolerance was reached. Blood lactate was analyzed by the enzymatic method. Differences in work rate, VO2, %VO2max, VE, HR, and R at ATLA(AT determined by the increase in blood lactate) and at ATGE (gas exchange AT based on the non-linear increases in VE, VCO2, and other respiratory parameters), respectively, were all found to be statistically insignificant. There was a significant correlation (r = 0.866, p less than 0.01) between ATLA and ATGE when expressed i VO2 values (l/min). There was also a significant correlation between ATLA and VO2max (r = 0.778, p less than 0.01). These results indicate that the commonly used Douglas bag method could provide a valid non-invasive measure of anaerobic threshold.

Acidosis↗
PubMed1981

Effects of cholesterol-rich diet and hypolipidemic drug (clofibrate, CPIB) on the adrenal cortex in rats--ultrastructural stereological and biochemical analysis.

Stereological analysis at the electron microscope level was performed on zona fasciculata and zona reticularis of the adrenal cortex of male rats maintained on normal rat chow, clofibrate (hypolipidemic drug), cholesterol-rich diet or cholesterol-rich diet plus clofibrate. The purpose of this study is to know whether the alteration in the serum cholesterol level is accompanied by an alteration in the ultrastructure and steroidogenic activity of the adrenal cortex, and to compare these changes with those of Leydig cells reported previously. The corticosterone level in both serum and the adrenal tissue of cholesterol-fed rats remained unchanged. Treatment of the cholesterol-fed rats with clofibrate caused a significant rise in the serum corticosterone level but the concentration in the adrenal remained unchanged. Lipid droplets increased in number and volume significantly in both cortical zones in all experimental groups as compared with the control group. But neither cholesterol feeding nor clofibrate treatment of normal rats caused a change in the volume or surface area of smooth endoplasmic reticulum (ER). Treatment with clofibrate on the cholesterol-fed rats resulted in a decrease in the volume of smooth ER in both cortical zones. Mitochondria showed no change except for a decrease in volume and inner membrane surface area of zona reticularis of cholesterol-fed rats. Peroxisomes did not proliferate but rather decreased in clofibrate-treated rats. These changes in the adrenal cortex were different from those in Leydig cells. Possible reasons for these differences were discussed.

Adrenal Cortex↗
PubMed1980

Effects of cholic acid, chenodeoxycholic acid, and their related bile acids on cholesterol, phospholipid, and bile acid levels in serum, liver, bile, and feces of rats.

Effects of sodium cholate, deoxycholate, chenodeoxycholate, and lithocholate on serum and liver cholesterol levels, bile flow, biliary cholesterol, phospholipids, and bile acids, and fecal sterols and bile acids were examined in Wistar strain male rats fed either an ordinary diet or a 2% cholesterol diet. Cholate and deoxycholate increased serum and liver cholesterol levels, serum pre beta-lipoprotein, bile flow, and biliary secretion of cholesterol, phospholipids, and bile acids, but chenodeoxycholate and lithocholate did not. The total amounts of sterols and of bile acids in the feces did not differ between the cholate and the chenodeoxycholate groups. All the bile acids except lithocholate decreased fecal coprostanol when the diet included cholesterol. Cholate and deoxycholate produced similar bile acid compositions in the bile and feces, as was the case between chenodeoxycholate and lithocholate, though chenodeoxycholate slightly increased the amount of muricholic acids, and lithocholate that of hyodeoxycholic acid, in the feces. The effects of cholate and deoxycholate are similar to each other but different from that of chenodeoxycholate or lithocholate in rats. Cholate causes marked accumulation of cholesterol in tissues, increased bile flow and biliary lipid secretion but chenodeoxycholate does not. Cholate is absorbed much more efficiently than chenodeoxycholate.

Animals↗
PubMed1980

Cystosarcoma phyllodes of the breast with features of malignant fibrous histiocytoma.

A case of a 33-year-old female with metastasizing malignant cystosarcoma phyllodes of the left breast showing histologic features of malignant fibrous histiocytoma is reported. Metastases consisting of only undifferentiated mesenchymal cells were found in the lungs, liver, pleurae, kidneys, ileum, and vertebrae. Seven cases of fibrohistiocytic tumors of the breast previously recorded in the literature were reviewed. Although rare, this type of tumor should be included in the differential diagnosis of mesenchymal mammary tumors.

Adult↗
PubMed1980

Development of 132 Ir sources for brachytherapy.

Techniques for the production of three kinds of 192Ir sources, i.e. hairpin, single-pin and seed, for brachytherapy were developed in Japan Atomic Energy Research Institute. Platinumiridium, alloy wire sheathed with platinum tube in advance were irradiated by the JRR-2 or JRR-3 reactor. The platinum tube cuts off beta-rays so as to minimize unnecessary radiation exposure to patients. Irradiation conditions were determined to obtain the radioactivity of 0.74 GBq (20 mCi) for a hairpin, 0.37 GBq (10 mCi) for a single-pin and 0.37 X 10(-1) GBq (1 mCi) for a seed, respectively, at the end of irradiation. Fluctuation in the linear distribution of the radioactivity along the hairpin source or the single-pin source was small enough on the viewpoint of its application. No significant impurity or surface contamination was observed in the source produced with pre-encapsulation. Seed targets were loaded in a polyethylene tube so as to be suitable for the new treatment technique of tumor. Irradiation of seed targets, packed alternately with nylon spacers in a polyethylene tube, was found to be satisfactory for preparing ribbon sources.

Brachytherapy↗