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Biomedical subjects

N Takeuchi

Publications and source records attributed to N Takeuchi.

At least 271 records · Page 15Linked to original sources
PubMed1986

Effects of castration and testosterone administration on serum lipoproteins and their apoproteins in male spontaneously hypertensive rat.

Serum triglyceride and very low density lipoprotein (VLDL) concentrations were higher in male spontaneously hypertensive rat than in male control Wistar Kyoto rat, whereas serum cholesterol, phospholipids, and high density lipoprotein (HDL) concentrations were lower. Castration of hypertensive rats induced an increase in serum cholesterol, phospholipids, and HDL, and a decrease in serum triglyceride and VLDL. The cholesterol content of HDL increased, whereas the triglycerides decreased after gonadectomy of hypertensive rats. These changes in serum lipids and lipoproteins could be reversed by the administration of testosterone. Apolipoprotein E contents in VLDL and HDL of hypertensive rats were low when compared with control rats but rose after castration and could be reduced by testosterone administration. Hypertensive rats accumulated triglycerides and cholesterol in the liver, which resulted in an increase of liver weight. Castration reduced the hepatic lipids as well as liver weight. The effects of castration and testosterone treatment on lipids and lipoproteins were more prominent in spontaneously hypertensive rats than in control rats. These results suggest that testosterone reduces VLDL catabolism which is related to changes of apolipoprotein composition, and that hypertensive rats are more sensitive to testosterone than control rats.

Animals↗
PubMed1986

[A study of prostatic tissue levels of latamoxef, cefoperazone and cefotaxime].

Although Cephem antibiotics are transferred to the prostatic fluid in relatively low levels, they are clinically effective for bacterial prostatitis. In the present study, the prostatic tissue concentration of Latamoxef (LMOX), Cefoperazone (CPZ) and Cefotaxime (CTX) were determined, and their penetration rates into the prostatic tissue were analyzed. Before the transurethral resection of the prostate (TUR-P), 2 g of LMOX (21 patients), 1 g of CPZ (15 patients) and 2 g of CTX (14 patients) were intravenously administered in a total of 50 patients with benign prostatic hypertrophy at our two Hospitals. The prostatic tissue was taken by TUR-P at 30 minutes and 60 minutes after the injection. The serum concentration and the prostatic tissue concentration of the three antibiotics were determined by the bioassay method. Additionally their serum concentration and the prostatic tissue concentration in the six cases of CTX-injected patients were also determined by high performance liquid chromatography (HPLC). The penetration rate into the prostatic tissue was obtained by the formula; the penetration rate = the prostatic tissue concentration/the serum concentration. The prostatic tissue concentrations determined by the bioassay method were, 36.9 +/- 10.6 micrograms/g at 30 minutes after the injection of 2 g of LMOX and 28.0 +/- 9.0 micrograms/g at 60 minutes, 31.0 +/- 8.3 micrograms/g at 30 minutes after the injection of 1 g of CPZ and 21.1 +/- 10.0 micrograms/g at 60 minutes, and 8.8 +/- 4.1 micrograms/g at 30 minutes after the injection of 2 g of CTX and 4.5 +/- 2.0 micrograms/g at 60 minutes (mean +/- S.D.). The penetration rates determined by the bioassay method were 36.2 +/- 10.9% at 30 minutes after the injection of LMOX and 34.8 +/- 15.3% at 60 minutes, 43.6 +/- 14.4% at 30 minutes after the injection of CPZ and 39.7 +/- 24.1% at 60 minutes, and 11.1 +/- 4.1% at 30 minutes after the injection of CTX and 9.6 +/- 3.8% at 60 minutes (mean +/- S.D.). The penetration rate of CPZ and LMOX were significantly higher than that of CTX (P less than 0.05, P less than 0.01). In 6 of the 14 CTX-injected patients, the serum and prostatic tissue concentrations of CTX and its metabolite, desacetyl-CTX, were also determined by HPLC. The penetration rate of CTX into the prostatic tissue was obtained by the formula; the penetration rate of CTX = the prostatic tissue concentration (CTX + Desacetyl-CTX)/the serum concentration (CTX + Desacetyl-CTX).(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1986

[Diastolic left ventricular pressure-mitral valve flow velocity curve: influence of heart rate change induced by atrial pacing].

To assess the left ventricular (LV) diastolic properties, the influence of heart rate change induced by atrial pacing on LV pressure-mitral valve (MV) flow velocity curves was studied. Simultaneous recording of MV flow velocity using pulsed Doppler echocardiography and LV pressure via a catheter-tip micromanometer was performed in 12 cases with past history of Kawasaki disease. Heart rates were increased in gradations of 10 beats from rest to 180 beat/min, or to the time when A-V block occurred. Diastolic LV pressures and MV flow velocities were plotted manually every 10 msec to establish pressure-velocity relationships at each heart rate. The relationship of LV pressure and MV flow velocity was non-linear, and formed a loop. At rest, this loop showed counterclockwise rotation (CCR) in all cases. By increasing heart rate, rotation changed from CCR to clockwise rotation (CR), except in two cases. With much greater increase in heart rate, CCR reappeared in five cases (second CCR). CCR may indicate that the increment of MV flow is smaller than the fall in LV pressure in the early diastolic filling period, suggesting the existence of inflow resistance. This is thought to be physiologic, and it is suspected that it is produced mainly by the MV and subvalvular structures. CR indicates that the MV flow velocity increases more rapidly than the fall in LV pressure, demonstrating that the resistance to inflow is reduced by increasing heart rate, and the increment of left atrial (LA) driving pressure plays a main role. In a case with simultaneous recording of LA and LV pressures, LA pressure became elevated and the LA-LV pressure gradient increased with an increasing heart rate. This suggests that the increment of LA pressure relates to a decrease of inflow resistance. The second CCR suggests that a resistance is produced beyond a capacity to compensate for elevated LA pressure. It can be speculated that this resistance is related to visco-elasticity of the LV, in addition to the MV and subvalvular structures.

Blood Flow Velocity↗
PubMed1986

Cholesterol gallstones in alloxan-diabetic mice.

Normal and alloxan-diabetic male mice (Crj-ICR) were fed a diet containing 0.5% cholesterol for 5 and 10 weeks, and gallbladder bile was analyzed for cholesterol, phospholipids and bile acids, feces for sterols and bile acids, and plasma and liver for cholesterol, phospholipids, and triglycerides. Normal mice developed no gallstones but the diabetic mice developed cholesterol gallstones with an incidence of 70% by 5 weeks and 80% by 10 weeks after feeding of the cholesterol diet. Diabetic mice fed the ordinary diet also developed stones (23%) by 10 weeks. In the diabetic mice, the gallbladder was enlarged about threefold, and biliary lipid concentration, diet intake, and fecal excretion of sterols and bile acids increased but body weight decreased. Cholic acid and beta-muricholic acid comprised over 40% each of the total biliary bile acids in normal mice, but cholic acid increased to about 80% and beta-muricholic acid decreased to a few percent in the diabetic mice. Fecal excretion of bile acids increased after cholesterol feeding in both normal and diabetic mice, but the increased bile acid in the normal animals was beta-muricholic acid and that in the diabetic mice was deoxycholic acid. The mice that developed gallstones showed a marked increase in biliary cholesterol value and decreases in gallbladder bile and bile acid concentration, but no difference in biliary and fecal bile acid composition, bile acid synthesis, fecal sterols, or plasma and liver lipid levels. Cholesterol absorption was increased in the diabetic mice when examined by plasma 14C/3H ratio and fecal 14C-labeled sterol excretion after a single oral administration of [14C]cholesterol and a simultaneous intravenous injection of [3H]cholesterol. These data led to the conclusion that cholesterol gallstones developed in alloxan-diabetic mice fed excess cholesterol, due to the hyperphagia and the enhancement of cholesterol absorption caused by increases in the synthesis and secretion of cholic acid.

Administration, Oral↗
PubMed1985

Aging changes of riboflavin concentration and glutathione reductase activity in erythrocytes.

Aged erythrocytes obtained by fractionation using gradient centrifugation with Dextran 40, showed lower glutathione reductase activity and riboflavin content than young cells. However, both young and old cells displayed almost the same increase in enzyme activity upon addition of flavin adenine dinucleotide to the test hemolysate in vitro. The lipid peroxide content in the cell membranes showed no consistent changes with aging.

Centrifugation, Density Gradient↗
PubMed1985

Preparation of tritium standard gas by the use of tritiated methane.

Tritium standard gas for calibrating radioactivity detectors was prepared by the use of tritiated methane synthesized by the reaction of tritiated water with aluminum carbide at ca. 470 degrees C. A long-path proportional counter was used to standardize the radioactivity of the prepared gas. Tritiated gas of less than 10(4) Bq could be measured by this counter with the overall error of 3.5% (3 sigma). Finally, two types of standard were prepared in a metal cylinder and a glass ampoule. The latter type could be used as a handy calibration source for detectors.

Aluminum↗
PubMed1985

[The residual calculi in conservative operation for renal calculi].

One hundred and three kidneys with calculi in 100 patients, were treated by conservative renal surgery from Jan., 1980 to Dec., 1982. The operative technique consisted of pyelolithotomy, extended pyelolithotomy, dismembered pyelolithotomy, nephrolithotomy (bivalve or anatrophic nephrolithotomy) partial nephrectomy and pyelo-nephrolithotomy. Intraoperative X-ray and coagulum lithotomy were employed when pyelolithotomy was performed. Thirty-five residual calculi in 20 kidneys were observed on postoperative X-ray film. The rate of residual calculi was 19.4%. Factors causing residual calculi, were analysed on these 103 kidneys. The factors were as follows; the shape of calculi: staghorn calculus with multiple small calculi, the shape of the renal collecting system: narrow pelvis with narrow caliceal neck and dilatated calices, and the operative technique: nephrolithotomy. These results suggested that it would be necessary to minimize residual calculi when performing nephrolithotomy.

Adolescent↗
PubMed1985

[Surgical removal of the staghorn calculi in the solitary kidney patients].

Seven patients undergoing surgical removal of extensive renal calculi involving a solitary kidney are reviewed. Problems arising from the surgery for the extensive renal calculi in a solitary kidney patient are demonstrated and indication of the surgery is also discussed. From January, 1978 to July, 1984, extensive renal calculi were removed in 7 solitary kidney patients. The operative technique for removing calculi consisted of anatrophic nephrolithotomy (in 2 patients) and ex vivo surgery (in 5 patients). There were 2 operative deaths and 2 major complications. Calculi were completely removed in 6 and 1 patient undergoing anatrophic nephrolithotomy, had a 3 X 4 mm residual calculus. The postoperative serum creatinine was improved in 5 patients. These major complications were observed in the patients who had severe renal dysfunction during the early postoperative period. It was indicated that good renal function should be maintained even during the early postoperative period in the surgery on a solitary kidney patient. Investigating injury to the operated kidney, the early postoperative serum creatinine level was analysed in these 7 patients and 3 patients undergoing ex vivo surgery for removal of aneurysm in a solitary kidney. The results indicated that nephrotomy was the most extensive damage to the kidney. However, pyelotomy and cold ischemia during ex vivo surgery, are not always harmful. In performing surgery for extensive renal calculous disease involving a solitary kidney, we should choose pyelotomy rather than nephrotomy in in situ operation. Ex vivo surgery can provide an effective treatment.

Adult↗
PubMed1984

A method for testing an extended poisson hypothesis of spontaneous quantal transmitter release at neuromuscular junctions.

A statistical method for testing the Poisson hypothesis of spontaneous quantal transmitter release at neuromuscular junctions has been proposed. The notion of the Poisson hypothesis is extended so as to allow for nonstationarity in the data, since nonstationarity is commonly seen in the occurrence of spontaneous miniature potentials. Special emphasis has been put on the nonstationary analysis of the quantal release. A time scaling technique has been introduced and is discussed for the analysis. Artificially generated data, which simulate three types of nonstationary spontaneous quantal release, i.e., Poisson, non-Poisson-clustered, and non-Poisson-ordered types, were analyzed to demonstrate the effectiveness of the method. Some sets of miniature endplate potentials, intracellularly recorded at frog sartorius neuromuscular junctions in low Ca++ and high Mg++ solutions showing apparent nonstationarities, were analyzed as illustrative examples. The proposed method will extend the range of applicable data for the statistical analysis of spontaneous quantal transmitter release.

Acetylcholine↗
PubMed1984

Atheromatous embolization. Report of two cases with unusual complications.

Two cases of spontaneous atheromatous embolization associated with unusual complications are presented. One is an 85-year-old man who developed an acute abdomen and underwent a surgical resection of totally infarcted left-sided colon. Histologically, multiple acute atheromatous emboli were found occluding the serosal and pericolic mesenteric arteries causing transmural necrosis of the involved portion of bowel. The other is an 80-year-old woman who had had a coronary heart disease, hypertension, and renal insufficiency, and terminally developed a rapid deterioration of renal function and melena. Postmortem examination showed a severely, ulcerated, aortic atherosclerosis and widespread, recurrent, atheromatous emboli in many abdominal organs with the resultant severe nephrosclerosis, gastrointestinal mucosal hemorrhagic necrosis, and multiple infarcts in the pancreas and spleen. In addition, there was focal cortical necrosis of the kidneys accompanied with glomerular capillary fibrin thrombi indicating disseminated intravascular coagulation (DIC). These findings seen in the present two cases were briefly discussed in light of the previous pertinent literature.

Aged↗