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Biomedical subjects

K Ota

Publications and source records attributed to K Ota.

At least 775 records · Page 43Linked to original sources

Short-time hemodiafiltration using polymethylmethacrylate hemodiafilter.

Three times 3 hr/wk hemodiafiltration (simultaneous hemofiltration and dialysis: HDF) using Toray HDF system has been carried out on 4 patients. Filters used were Toray Filtryzers (membrane: polymethylmethacrylate, surface area 1.15 M2) with a dialysate flow of 500 ml/min. Nine to 10 L of body fluid was removed and 7-8 L of substitution fluid was reinfused distal to the filter (postdilution). Short-time HDF was favorable accepted by the patients. Blood pressure was stable, and disequilibrium syndrome negligible. Clinical courses as well as laboratory findings of the patients were satisfactory. The reduction rate of middle to larger molecules was 20 to 100% higher compared to conventional HD as measured by chromatogram. Loss of amino acids was about 3 gm/treatment. Reduction of hormones was negligible and no depletion syndrome was observed throughout the observation period up to 10 mos. Acidosis was corrected within 3-4 hrs. Elevated blood concentration of lactate and acetate gradually decreased to a pretreatment level within 2-3 hrs after termination of the procedure. Removal of middle molecules by HDF, in addition to removal of small molecules by conventional hemodialysis, is considered to be the treatment of choice for uremic patients.

Acrylic Resins↗

Enhancement of DNA chain breakage by bleomycin A2 in the presence of microsomes and reduced nicotinamide adenine dinucleotide phosphate.

Chain breakage in DNA induced by bleomycin A2 (BLM) was enhanced more than 150-fold by the reduced nicotinamide adenine dinucleotide phosphate-dependent electron transport system of rat liver microsomes. However, the enhancement effect on DNA was partially reduced by the preincubation of BLM with the microsomal systems. BLM-Cu2+ was found to stimulate considerably microsomal reduced nicotinamide adenine dinucleotide phosphate-dependent oxygen consumption and malondialdehyde formation, whereas BLM inhibited both of the effects. These findings suggest that the pharmacological action of BLM is strongly affected by a membrane system, such as microsomes, that produces free radicals.

Animals↗

Genetic polymorphism of eserine resistant esterases in canine plasma.

Six plasma eserine resistant esterase phenotypes were observed in a population of 1438 dogs consisting of 38 breeds. Analysis of parentage records of the dogs examined revealed that the phenotypic variation of eserine resistant esterases was controlled by 3 codominant alleles ESA, ESB and ESC at one autosomal locus. The gene frequency of ESB was high in most of the breeds examined. Allele ESC was only seen in 5 Japanese native breeds, Akita, Shikoku, Hokkaido, Shinshu-Shiba and Mino-Shiba, and in a Spitz dog. Allele ESA has a low frequency in Japanese breeds but a higher frequency in some of the European breeds tested.

Alleles↗

Genetic variants of glucose phosphate isomerase (E.C. 5.3.1.9) in canine erythrocytes.

Genetic polymorphism of glucose phosphate isomerase (GPI) was found in the erythrocytes of dogs of six Japanese breeds by using starch gel electrophoresis. Analysis of parentage records of dogs revealed that the phenotypic variation of erythrocyte glucose phosphate isomerase was controlled by one autosomal locus with two codominant alleles, GPIA and GPIB. The allele GPIB was observed in the following breeds: San'in-Shiba, Shinshu-Shiba, Shikoku, Kai and Kishu, but not in Hokkaidoes and Akitas. All the dogs belonging to 25 European breeds, 5 oriental or China-origin (except Japan) breeds examined in this experiments had the genotype constitution GPIA/GPIA, whereas one Dalmation dog was heterozygous GPIA/GPIB.

Alleles↗

Noonan syndrome with hypertrophic obstructive cardiomyopathy.

A case of a 20 years old female who had Noonan syndrome associated with obstructive cardiomyopathy was presented. It is well known that Noonan syndrome is frequently complicated with cardiac anomaly, and although no autopsies were performed two cases have been diagnosed clinically as Noonan syndrome accompanied with idiopathic cardiomyopathy in our country. The present case would be the first autopsied case in Japan of Noonan syndrome associated with idiopathic obstructive cardiomyopathy.

Adult↗

Calcium metabolism in aging inhabitants of mountain versus seacoast communities in the Kii Peninsula.

A survey was conducted on age-related changes in various measures of calcium metabolism in 609 men and women over the age of 30 (more than half were over the age of 60) in two communities of the Kii Peninsula at the central southern tip of the Japanese mainland. One community was on Oshima Island, with adequate nutritional intake; the other community was in the mountainous Shichikawa district, with a low intake of calcium and protein. The subjects of the Shichikawa study showed shorter stature, higher prevalence of lumbago, thinner clavicular cortex, lower serum levels of phosphorus, total protein and cholesterol, and a higher level of alkaline phosphatase than did the subjects of the Oshima study. There was no difference in the serum calcium levels.

Adult↗

Control of parathyroid hormone hydrolysis by the kidney.

In order to assess the role of the kidney in controlling the degradation, fate, half-life, and consequently the functional level of the parathyroid hormone in vivo, highly purified bovine parathyroid hormone (bPTH 1-84) and synthetic N-terminal peptide of the bovine parathyroid hormone (bPTH 1-34) were iodinated and their hydrolysis by the kidney and liver tissue of rats were measured under various levels of parathyroid function and calcium metabolism. While the hydrolysis of bPTH 1-84 did not change significantly in response to acute change of serum parathyroid hormone in response to injections of EDTA, phosphate, and calcium or after parathyroidectomy, less bPTH 1-34 was hydrolyzed 60 min after injection of EDTA or phosphate along with the rise of serum PTH than in the controls. No significant change was found in the hydrolysis of bPTH 1-34 after calcium infusion or parathyroidectomy with a consequent fall of serum parathyroid hormone. Increase of calcium ions in the incubation medium in vitro resulted in a more pronounced increase of bPTH 1-34 hydrolysis than that of bPTH 1-84. Hydrolysis of the N-terminal portion of parathyroid hormone probably plays a more important role in the acute control of the functional level of the parathyroid hormone than the hydrolysis of the whole molecule.

Animals↗

Effect of 1alphaOH-vitamin D3 in a case of pseudohypoparathyroidism.

A 37-year-old woman with typical features of pseudohypoparathyroidism (chronic tetany, paresthesia, persistent hypocalcemia, round face, short stature, short metacarpals and metatarsals, cucutaneous calcification and lack of response to exogenous and endogenous parathyroid hormone as regards urinary phosphate and cyclic AMP excretion) was treated with oral administration of 2 microgram/day of 1alphaOH-vitamin D3. Serum calcium started to rise within 3 days returning to the normal level with disappearance of symptoms referrable to hypocalcemia. Such a favorable effect of a small dose of 1alphaOH-vitamin D3 in a patient with typical hypoparathyroidism suggests an important role of disturbance of 1alpha-hydroxylation of vitamin D3 by the kidney in the pathogenesis of calcium and phosphorus abnormality in this disease. Forty-four cases of pseudohypoparathyroidism in the Japanese literature were briefly reviewed.

Administration, Oral↗

Clinical experience with circumferentially reinforced expanded polytetrafluoroenthylene (E-PTFE) graft as a vascular access for haemodialysis.

Circumferentially reinforced E-PTFE grafts were implanted 50 times in 46 patients. Seven grafts became occluded during the observation period of 233 patient-months. Puncture and haemostasis were quite satisfactory in the majority of the patients. Histologically, the inner surface of the grafts was covered with a thin fibrin layer. Puncture sites were stuffed with fibro-fibrinous tissue preventing bleeding or aneurysmal dilatation. Clinical experience has proved the E-PTFE graft to be a suitable vascular prosthesis for blood access.

Adolescent↗

Aging and parathyroid hormone secretion.

Influence of age on parathyroid hormone secretion and release was studied in vitro using rat parathyroid glands in culture and in vivo by EDTA injection. Parathyroid hormone was measured by radioimmunoassay using guinea pig antibody for bovine parathyroid hormone and 125I-labeled synthetic N-terminal peptide of bovine parathyroid hormone. Significantly less PTH was released from parathyroid glands of 18-mo-old rats than from those of 1 mo of age at various calcium concentrations of the medium in vitro. Secretion of parathyroid hormone in response to EDTA-induced hypocalcemia in vivo was also less in older rats than in younger ones, giving lower deltaPTH/deltaCa values in the older animal. Secretion of parathyroid hormone therefore appears to decrease along with aging in rats.

Aging↗

Changes in body weight, milk production, food and water consumptions and vaginal smears in rats during prolonged lactation.

Concurrent observations were made in the rat on the changes in the milk production, body and organ weight, food and water consumptions and in the ovarian function in two separate series of experiments in which the period of lactation was prolonged to 60 and 45 days, respectively, by replacing suckling pups by younger ones. In most of the variable examined, marked changes occured between day 20 and 30 of lactation, that is, at the stage correspondong to the end of the normal lactation period. Milk production rate during prolonged lactation expressed by daily gain in weight of litters decreased to 60% of the level before day 20, and was associated with a great reduction of nucleic acid contents of the mammary gland. Definite decreases in weight of the anterior pituitary and the adrenal glands were observed. The food intake remained constant from day 15 of lactation onwards, therefore, the feed efficiency for milk production declined gradually during the period of normal lactatation remaining at a low level thereafter.. After the first recurrence of vaginal estrus which also occured between day 20 and 30, the replacement of litters was followed by the appearance of estrus, whereas replacement before day 15 did not affect the ovarian function. In addtition to these changes, a depressing effect of estrus on the milk production was observed.

Adrenal Glands↗