Search PubMed⌕ Search

Biomedical subjects

K Ohta

Publications and source records attributed to K Ohta.

At least 811 records · Page 45Linked to original sources
PubMed1984

[Studies on pathogenesis of muscular dystrophy: levels of thiobarbituric acid-reactive products in avian muscular dystrophy].

Lipid peroxidation and other free radical reactions are known to disrupt and damage cellular structures and function, and it has been postulated as possible mechanisms of cellular damage of muscular dystrophy because increased levels of thiobarbituric acid (TBA)-reactive products and increased activities of superoxide dismutase and glutathione peroxidase were reported in avian muscular dystrophy. We reported that activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase were significantly increased in avian muscular dystrophy from the early developmental stage. Since these enzymes protect cellular structures from free radicals and peroxides, increased activities of these enzymes would indicate increased formation of radicals. Then it seems to be important to assay TBA-reactive products which indicate tissue malondialdehyde content, a by-product of lipid peroxidation. We used dystrophic chickens of New Hampshire series line 413 and their controls line 412 for assay of TBA-reactive products. Four or five birds from respective lines were killed by decapitation two weeks, four weeks and four months after hatching. The superficial pectoral muscle was immediately weighed and levels of TBA-reactive products in the muscle homogenate was assayed by fluorophotometry according to the modified method of Ohkawa and Tanizawa. Levels of TBA-reactive products were significantly higher in dystrophic chickens at all stages of development studied than those of the control group. At two weeks of age morphological changes are minimum if present and increased levels of TBA-reactive products cannot be considered as a secondary change of morphological alterations. Therefore, the results indicate involvement of lipid peroxidation damage in pathogenesis of this avian muscular dystrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Correlation of the real-time ultrasonographic appearance of hepatic hemangiomas with angiography.

The ultrasonographic appearance of hepatic hemangiomas was studied in 19 patients (31 lesions). The detectability rate by real-time ultrasonography was 77%. A hyperechoic, sharply-marginated and internally homogeneous lesion is highly suggestive of hemangioma. If the hypoechoic lesion has homogeneous internal echoes and/or strong marginal echoes, it is also suggestive of hemangioma. It is difficult to detect small lesions in the lower lateral part of the right lobe and lesions in the right lobe immediately under the diaphragm. Computed tomography should be the next procedure of choice in the evaluation process. If the computed tomography is not characteristic, angiography should be done to confirm the diagnosis.

Adult↗
PubMed1983

Immunocytochemistry of the Microtubules of fat-laden cells. Brown fat cells and adrenocortical cells in primary monolayer culture.

Cytoplasmic microtubules of fat-laden cells containing fine lipid droplets, such as brown fat cells and adrenocortical cells, were studied in relation to the metabolism of intracellular lipid. In these cells, the amount and distribution of lipid droplets reflect the state of inherent cellular function. Materials used were primary monolayer culture of fetal rat brown fat cells and that of bovine adrenocortical cells. The method was the immunocytochemistry with anti-tubulin antibody. When brown fat cells were being lipolyzed or the steroidogenesis of adrenocortical cells were being stimulated, the cytoplasmic microtubules in the cells were organized in a radial pattern in response to the behavior of the lipid droplets. It is assumed that the microtubules were in the regulation of cellular function in terms of the metabolism of lipid droplets in these cells. We have devised, in the course of the current study, a double fluorescence technique as an observational method whereby microtubules were observed immunocytochemically and lipid droplets by a secondary fluorescence with phosphine E staining.

Adipose Tissue, Brown↗
PubMed1983

Human tonsillar IgE biosynthesis in vitro. I. Enhancement of IgE and IgG synthesis in the presence of pokeweed mitogen by T-cell irradiation.

A study of the events regulating human IgE biosynthesis in vitro was undertaken with tonsillar lymphocytes. IgG synthesis was also studied to evaluate the specificity of our observations. T-cell irradiation significantly enhanced synthesis of IgE by pokeweed mitogen (PWM)-stimulated B cells from 12 of 18 donors and IgG in all 18 donors. This enhancement was the result of de novo immunoglobulin synthesis, since the amount of IgE and IgG spontaneously released from lysed and lysed-and-cultured mononuclear cells was significantly less than that detected in the cell cultures, and the augmentation was completely ablated by the treatment of the cells with cycloheximide or mitomycin C. Enhancement was also dependent on the presence of PWM; T-cell irradiation did not enhance IgE synthesis in unstimulated cultures. Moreover, this enhancement was also observed in the co-cultures of B cells and allogeneic irradiated T cells. These observations suggest that radiosensitive T cells exert a suppressive activity that contributes to regulation of human IgE and IgG synthesis and that the suppressor function as well as the helper function can overcome allogeneic disparities.

Adolescent↗
PubMed1983

Hormonal sensitivity of brown fat cells of fetal rats in monolayer culture.

The primary monolayer culture of brown fat cells was performed with the brown adipose tissue of fetal rats as the material. Brown fat cells in the culture were highly sensitive to some hormones. Insulin had a marked effect of lipogenesis and it made the cells contain large multilocular lipid droplets. Lipolysis is also mediated by hormones, e.g., epinephrine or ACTH etc., and lipolytic process was controlled through cyclic AMP system. Brown fat cells of fetal rats in monolayer culture seem to be a suitable material for long-term experiment of lipogenesis and lipolysis.

Adipose Tissue, Brown↗
PubMed1983

Plasma exchange for treatment of intractable psoriasis.

Hemofiltration and plasma exchange, using a plasma separator with membranes, were used in 14 psoriatic patients. The efficacies of the treatments were compared. Among the patients, 13 were treated with hemofiltration and/or direct hemoperfusion, 5 experienced complete remission, 5 improved, and 3 remained unaffected. In these 3 cases, plasma exchange was performed. The first patient, who suffered from psoriasis pustulosa with arthropathica, achieved complete remission with only two treatment of 2-L plasma exchange. Joint pain was also eliminated. Both skin lesions and joint pain were markedly improved in the second patient, who suffered from psoriasis vulgaris with arthropathica. The third patient showed marked improvement with only two plasma exchanges, and is under continuing observation.

Adult↗
PubMed1983

Role of tween 80 and monoolein in a lipid-sterol-protein complex which enhances ethanol tolerance of sake yeasts.

An exogenous ternary complex composed of Tween 80, ergosterol, and albumin increased the final ethanol concentration of fermentation by sake yeasts from 17.2 to 19.0% (vol/vol) and reduced the fermentation time from 30 to 25 days. Likewise, a complex of monoolein, albumin, and either ergosterol or ergosteryl oleate increased the final ethanol concentration of fermentation to 19.7 or 19.8% (vol/vol), respectively, and reduced the fermentation time to 25 days. Both Tween 80 and monoolein promoted the fermentative activity (Q(CO(2) )) of cells, and the effect was enhanced by the presence of ergosterol.

Journal Article↗
PubMed1983

Ultrasonographical diagnosis of fatty liver: significance of the liver-kidney contrast.

In order to investigate the reliability of ultrasonography in the diagnosis of fatty liver, retrospective evaluation was made of abdominal echograms in 45 patients with various diffuse liver diseases who underwent liver biopsy within 2 weeks after the ultrasound study. Instead of the well-recognized but subjective diagnostic criterion, i.e. the bright liver pattern, liver-kidney contrast is proposed as a new criterion. The liver-kidney contrast is based on the brightness of the liver in comparison to the renal parenchyma where fatty change seldom occurs. Combination of this liver-kidney contrast with two other well-known ultrasonographical findings of fatty liver, vascular blurring and deep attenuation, enables us to grade fatty change semiquantitatively. When fatty change of over 30% in the hepatic lobule was adopted as the definition of fatty liver, the satisfaction of both liver-kidney contrast and vascular blurring presented an ultrasound diagnostic criterion for fatty liver, with sensitivity of 83%, specificity of 100%, and an accuracy of 96%.

Abdominal Muscles↗
PubMed1983

A case of idiopathic fatty liver detectable only by ultrasonography.

A 40-year-old man was diagnosed as fatty liver according to our ultrasonographical criteria for fatty liver, i.e., liver-kidney contrast in the ultrasound mass screening of the liver, biliary tract and pancreas. He lacked any signs or symptoms, nor any known causes of fatty liver, i.e., obesity, diabetes, hyperlipidemia, ingestion of alcohol or drugs. Liver biopsy of this patient revealed fatty change of about 50% of the hepatic lobules. It has been difficult to suspect the presence of latent fatty liver which lacked both the abnormality in the liver function test and hepatomegaly, and even impossible when it lacked any risk factors. In the future as the ultrasonography becomes more generally used as a primary screening examination, "idiopathic latent fatty liver", like this patient, will be more frequently found and this, in turn, will contribute to the progress of the epidemiology and etiology of fatty liver.

Adult↗
PubMed1983

Genetic studies of autoimmunity in New Zealand mice. IV. Contribution of NZB and NZW genes to the spontaneous occurrence of retroviral gp70 immune complexes in (NZB X NZW)F1 hybrid and the correlation to renal disease.

We designed a polyethylene glycol precipitation method for detecting retroviral gp70-anti-gp70 immune complexes (gp70 IC) in the circulation of mice. To determine the genetic contribution of NZB and NZW strains to the spontaneous occurrence of circulating gp70 IC in NZB X NZW (B/W)F1 hybrids, we measured these IC in female NZB, NZW, (NZB X NZW)F1 (B/W F1), B/W F1 X NZW backcross, and B/W F1 X NZB backcross mice. The highest amounts of gp70 IC were found in B/W F1 and the lowest in NZW mice, and the order of the average serum levels was B/W F1, B/W F1 X NZB, B/W F1 X NZW, NZB, and NZW. Genetic analyses suggested that two major dominant genes, one from NZB and the other from NZW, are involved in the formation of these gp70 IC. A single dominant gene of NZB strain determines the formation of these IC, and the magnitude is to a great degree modified (intensified) by the NZW gene. In addition, statistical analyses of data obtained in the studies of B/W F1 X NZW backcrosses suggested the presence of one additional dominant NZB gene that also regulates the magnitude of gp70 IC formation in concert with the other NZB gene. Since all these New Zealand mice share a high serum level of free gp70, the formation of gp70 IC represents the gene action on the production of anti-gp70 antibodies. Linkage studies showed that both of the major NZB and NZW genes are loosely linked to the H-2 complex but not to either the Mup-1 or coat color gene loci examined. The incidence of proteinuria correlated well with the serum level of gp70 IC in both B/W F1 X NZW and B/W F1 X NZB backcross mice.

Aging↗