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Biomedical subjects

K Ota

Publications and source records attributed to K Ota.

At least 757 records · Page 42Linked to original sources
PubMed1979

Continuous blood pressure monitoring during hemodialysis.

As the number of patients suffering from circulatory problems increases, continuous blood pressure monitoring during hemodialysis is desirable. Monitoring of the fistulated venous pressure was proven to be a satisfactory substitute for that of the systemic arterial pressure, after fistulated venous pressure had been ascertained to correlate strictly with systemic arterial pressure. Utilization of a double-lumened cannula, one lumen for blood outflow and another for monitoring of fistulated venous pressure, was established and showed clinical applicability. This principle is considered to be useful not only for blood pressure monitoring, but also for activation of a dialysis machine control system.

Animals↗
PubMed1979

A new method of urea removal using urease and expanded polytetrafluoroethylene membrane.

A new method for urea removal using a gas membrane is introduced along with some preliminary results. The membrane used was expanded polytetrafluoroethylene (E-PTFE) which is highly permeable to gaseous substances, while at the same time it is highly resistant to water permeation. In in vitro experiments using 10 mmol/L ammonia solution it was revealed that the single-pass reduction rate was approximately 95% at 30 degrees C at a flow rate of 200 ml/min. In animal experiments using four dogs, the extraction rate of urea was 40.4 +/- 4.4% after four hours of dialysis using 5 L dialysate. However, elevation of blood ammonia was observed in all dogs tested. Removal of ammonia by means of a gas membrane is considered to be feasible and has the possibility of being used for maintenance hemodialysis in combination with urease and charcoal.

Ammonia↗
PubMed1979

Lactation in the rabbit: mammary blood flow and cardiac output.

In anaesthetized rabbits, cardiac output (C.O.) and its distribution to the mammary glands, heart, liver and kidneys have been determined in established lactation (11--13 days), later lactation (26--27 days) and in virgins. During lactation, the volume of circulating blood, C.O., mammary blood flow and mammary weight were significantly greater than in virgins. There were no significant differences in C.O. and % C.O. received by the mammary glands between established and late lactation, and no significant decrease in mammary blood flow in late lactation. The weights of the liver and kidneys were significantly increased in lactation but there were no significant differences in liver, heart (coronary) and kidney blood flow. The rate of growth of the young was positively and significantly correlated with % C.O. received by the mammary glands and mammary weight, but not with C.O. Strong correlation was also observed between the % C.O. received by the mammary glands and mammary weight. There were no significant differences in C.O., mammary % C.O. and mammary blood flow in animals in established lactation 2--3 h and 24 h after suckling (i.e. shortly after and just before suckling). By 48 h after the last suckling mammary blood flow and % C.O., but not C.O., were significantly decreased. Possible factors causing these changes are discussed. The results are discussed in relation to the change in milk composition that occurs in late lactation in this species and to the role and effects of prolactin. It is suggested that events occurring during lactation have different sensitivities to prolactin.

Animals↗
PubMed1979

Hypothalamic hypernatremia due to volume--dependent ADH release, and its treatment with carbamazepine and clofibrate.

A 23-year-old man, diagnosed as having a pituitary adenoma at the age of 17 and received an operation 1 month ago showed a fluctuating hypernatremia and hypodipsia. The water deprivation, water load and hypertonic saline infusion tests were carried out. After a 14-hr water deprivation test, plasma osmolality was 310 mOsm/kg, plasma ADH was 1.5 microunits/ml, and urine osmolality was 591 mOsm/kg. On the water load test subsequently performed, the plasma osmolality decreased to 297 mOsm/kg, but the urine was still hypertonic. Infusion of 2.5% saline solution elicited paradoxically a marked diuresis and dilution of urine despite the elevàtion of plasma osmolality. On the treatment with carbamazepine and clofibrate, the urinary osmolality increased, the hypernatremia was normalized, and a marked natriuresis was elicited with a gain in body weight. These results suggested that the secretion of ADH is regulated by changes in blood volume rather than by the plasma osmolality in this patient. The hypernatremia may be explained as a disturbance or lack of osmoreceptor function for ADH release and the loss of thirst sensation, though the volume receptor still remains functioning for ADH secretion. Depletion of the extracellular fluid volume may be another contributing factor to the elevation of serum sodium level by enhancing the reabsorption of sodium from renal tubules.

Adult↗
PubMed1979

Increase of superoxide dismutase activity in various human leukemia cells.

(1) Superoxide dismutase activity in polymorphonuclear cells from human blood is considerably lower than that in lymphocytes. Macrophages from ascites show the middle level between the other two cells. (2) In myelocytic, monocytic, and lymphocytic leukemia cells, the enzyme activities are increased compared to those in the corresponding normal cells. (3) Gel electrophoresis patterns of all normal cells reveal bands corresponding to the cytosol and mitochondrial bands reported in previous studies. However, the mitochondrial Mn-containing superoxide dismutase activities are diminished or absent in leukemia cells. CN-insensitive superoxide dismutase activity in leukemia cells is not detected under the conditions.

Humans↗
PubMed1979

Orally diluting hemofiltration.

Orally diluting hemofiltration (ODHF), herein reported, is a new technique where the body fluid is purified by cooperative procedures of dilution-supplementation with oral electrolyte solution and filtration using the RP-6 dialyzer. One uremic patient was maintained for two months on a five-hour, three-times-per-week ODHF schedule, and another patient was maintained for four months on the same regimen with no supportive hemodialysis.

Administration, Oral↗
PubMed1978

[Degradation of the parathyroid hormone in the kidney and liver (author's transl)].

The cleavage of the parathyroid hormone has been reported to take place in various peripheral tissues, especially in the kidney and liver. In order to claify the mechanism of such a degradation, bovine PTH (bPTH 1--84) and its synthetic N-terminal peptide (bPTH 1--34) labelled with 125I by the chroramine-T method (125I-bPTH 1--84) and (125I-bPTH 1--34) or labelled with horseradish peroxidase Pox-125I-bPTH 1--84 and Pox 125I-bPTH 1 34) were used to study the disappearance from the blood stream and degradation and retension in the kidney and liver after intravenous injections in male Wiastar rats, weighing approximately 200g. Degradation of PTH was also studied in vitro, using isolated cells and a homogenate of the kidney and liver. PTH labeled with 125I and Pox was more readily degraded by the kidney than PTH labelled with 125I alone, but the opposite was found in the degradation by the liver. Isolated intact kidney cells degraded PTH less efficiently than the homogenate, but the isolated intact liver cells degraded PTH more efficiently than the homogenate, indicating the prominence of an intracellular mechanism of degradation in the kidney and an extracellular mechanism in the liver.

Animals↗
PubMed1978

Experimental results with the combination of bleomycin plus mitomycin C.

This investigation has established the following: 1. Bleomycin, in combination with mitomycin C or other quinone-containing anticancer agents, stimulated the damage to KB cells in culture. 2. In AH66 tumor-bearing rats, the simultaneous treatments of bleomycin plus mitomycin C extend the lifespan. 3. The bleomycin-induced DNA chain breakage was enhanced by the NADPH-dependent microsomal electron transport system. The enhancement was also observed at the level of isolated nuclei and cells. Vitamin K2 and mitomycin C increased breakage at the cellular level by bleomycin and NADPH. 4. Bleomycin-Cu2+ had tendency to increase the lipid peroxidation reaction by the microsomes. However, the reaction was effectively inhibited by antioxidants. 5. Bleomycin induced aldehyde formation from DNA breakage. The formation was effectively inhibited by scavenging reactions with hydralazine hydrochloride or isoniazid. The possibility of suppressing the side effect of bleomycin was discussed in relation to TBA reactive compounds.

Antibiotics, Antineoplastic↗
PubMed1978

Genetic variants of hemoglobin in canine erythrocytes.

Genetic polymorphism of hemoglobin was found in the erythrocytes of dogs of seven Japanese native breeds by using starch gel electrophoresis. Analysis of parentage records of the dogs revealed that the phenotypic variation of hemoglobin is controlled by one autosomal locus with two codominant alleles, HbA and HbB. the allele HbA occurred only in Japanese native breeds except Shikoku. The frequency of HbA in the Japanese breeds was low and 0.08. All the dogs belonging to 25 European breeds and 5 oriental origin (except Japan) breeds examined in this experimnets had the homozygous genotype constitution HbB/HbB.

Alleles↗
PubMed1978

Clinical evaluation of a pre-set ultrafiltration rate controller available for single pass and hemodiafiltration systems.

Introduction of high flux-type dialyzers, such as the RP-6, makes it necessary to devise an ultrafiltration rate controller for a single pass system. For this purpose, a new pre-set ultrafiltration rate controller has been developed and examined experimentally and clinically. The controller has twin chambers, each of which is divided into two symmetrical parts by a vertically-placed diaphragm. The diaphragm shifts repeatedly from right to left, aspirating in and driving out fresh or used dialysate alternately. If one removes a certain amount of used dialysate from a branch of the efferent line, negative pressure develops and aspirates an equal amount of water from the dialyzer. Therefore, extra dialysate obtained by a pump precisely reflects ultrafiltration rate. The controller has been used on five patients. The scheduled ultrafiltration rate was easily obtainable. The apparatus is also available for hemodiafiltration. Initial clinical trial has been promising.

Body Fluids↗