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Biomedical subjects

Y Hara

Publications and source records attributed to Y Hara.

At least 631 records · Page 35Linked to original sources
PubMed1987

Immunoregulatory abnormalities in autoimmune thyroid diseases.

We have investigated the ability of lymphocytes from normal subjects and patients with autoimmune thyroid diseases to respond to a thyroidal antigen (human thyroglobulin, hTG) and a non-thyroidal antigen (Keyhole limpet hemocyanin, KLH) in vitro, using a hapten (trinitrophenol, TNP)-carrier system. This system is based on the concept that the T helper cells which respond to hTG or KLH should stimulate anti-TNP antibody producing B cells in the presence of TNP conjugated hTG (TNP-hTG) or KLH (TNP-KLH). After 5 or 6 days of culture of peripheral blood mononuclear cells with pokeweed mitogen (PWM), PWM and TNP-hTG, or PWM and TNP-KLH, IgM anti-TNP and IgM anti-sheep red blood cell (SRBC) plaque forming cells (PFC) were enumerated. The results showed that (1) in normal controls, hTG caused only suppression in both TNP and SRBC response, and KLH caused dose-related enhancement and suppression in TNP response without a change in SRBC response, and (2) in patients, both hTG and KLH resulted in dose-related enhancement in TNP response without a change in SRBC response. These data suggest that patients with autoimmune thyroid diseases have regulatory cell abnormalities confined to a thyroid antigen.

Adult↗
PubMed1987

Spontaneous in vitro production of thyroglobulin specific helper factor in patients with autoimmune thyroid diseases.

We have investigated regulatory cell abnormalities in patients with autoimmune thyroid diseases through in vitro thyroglobulin (Tg) specific helper factor production. Helper activities were measured in the mice spleen cell assays, using hapten-carrier system. Peripheral blood leukocytes (PBL) from 5 out of 6 patients produced the Tg specific helper factor not only when they were stimulated in vitro with Tg but also when they were not stimulated. On the contrary, normal PBL did not produce the factor when they were not stimulated in vitro. However, 3 out of 5 normal PBL did produce the factor when they were stimulated in vitro with Tg. From several lines of studies, this helper factor was specific for Tg in its production and action. From these results it is concluded that (a) Tg specific helper T cells are already activated in vivo in patients with autoimmune thyroid diseases, indicating the presence of immunoregulatory abnormalities in these patients, and that (b) normal PBL have a potential to produce this helper factor when they are appropriately stimulated.

Biological Assay↗
PubMed1987

HLA immunogenetic heterogeneity in black American patients with Graves' disease.

Seventy-three American black patients with Graves' disease were typed for HLA-A, HLA-B, and HLA-DR antigens. There was a slight increase in HLA-DRw6 antigen frequency compared with 238 normal American black controls, but this was not significant after correction for the number of antigens tested. A significant increase in HLA-DR4 and HLA-DRw6 frequency was found in a subgroup of patients with exophthalmos (22.9% and 29.2% compared with 7.6% and 10.1% of normal black controls). There was a significant increase in HLA-DRw6 in a subgroup of patients who were thyroid antibody-positive (26.0%). The increment in HLA-DRw6 was higher in 32 patients who had both exophthalmos and who were antibody positive (37.5%). A significant increase in HLA-DR5 was found in a subgroup of patients who did not have exophthalmos and who were antibody-negative (83.3%). Our findings support previous evidence for immunogenetic heterogeneity in patients with toxic Graves' disease. In American blacks HLA-DRw6 is in some way associated with the disease in contrast to the well-recognized HLA-DR3 association in whites.

Black or African American↗
PubMed1987

[Changes in steroid enzyme activity in the human endometrium during the menstrual cycle].

Sulfokinase, sulfatase, 17 beta-HSD, 20 alpha-HSD, 3 beta-HSD and 5 alpha-reductase activity and steroid concentrations including estradiol, estrone, estrone-sulfate, progesterone, 20 alpha-dihydroprogesterone, DHA and DHA-sulfate in endometrial tissue were examined in order to study the changes in steroid metabolism in relation to the menstrual cycle in the human endometrium. Thirty-one (14) proliferative and 17 secretory) endometrial tissue samples were obtained from women who underwent hysterectomy. Low enzymatic activity of sulfokinase, sulfatase and 17 beta-HSD activity were observed in the proliferative phase (0.25, 8.5, 3.1 nmole/mg protein/h). A pronounced increase in enzymatic activity was observed in the early secretory phase and activity gradually decreased toward the mid and late secretory phase. On the other hand, 20 alpha-HSD and 3 beta-HSD activity did not change during the cycle. 5 alpha-reductase activity was not detectable under the conditions used. The concentration of progesterone in the secretory phase was significantly higher than that in the proliferative phase. The concentration of estradiol in the proliferative phase was significantly higher than that in the secretory phase. There was no significant change in the concentration of estrone, estronesulfate, 20 alpha-dihydroprogesterone, DHA or DHA-sulfate during the cycle. The relationship between the steroid concentration and the enzymatic activity was discussed. The results suggested an active role of the endometrium in controlling the biological effect of steroids.

Adult↗
PubMed1987

[Intraoperative radiotherapy].

Intraoperative radiotherapy, which delivers a large single dose of electrons to a tumor intraoperatively, is applied for locally advanced and/or difficult to cure malignancies which are rather difficult to treat by conventional external beams. Although this method was initially developed in Japan, increasing numbers of institutes have recently been working with IORT on a world-wide basis because of the increased availability of medical accelerators and the better results obtained. The malignancies for which IORT is indicated are cancers of the stomach, liver, biliary tract, pancreas, colo-rectum, urinary bladder, prostate and uterus, which are surrounded by normal tissues or organs with low tolerance doses, and also recurrent or difficult to cure malignancies of the brain, lung, mediastinum, bone and soft tissues are becoming candidates for IORT treatment.

Female↗
PubMed1986

ATP-dependent proton uptake by proteoliposomes reconstituted with purified Na+,K+-ATPase.

Proton transport catalyzed by the sodium pump was demonstrated using proteoliposomes reconstituted with purified pig kidney Na+,K+-ATPase. Intravesicular pH was monitored with fluorescence from fluorescein isothiocyanate dextran introduced into the vesicles. An ATP-induced ouabain-sensitive acidification of the intravesicular medium was observed, when the vesicles were incubated with ATP and without Na+. The ATP-induced acidification was blocked by either extravesicular Na+ or pretreatment of the enzyme with ouabain before reconstitution. Protonophores, X-537A or carbonyl cyanide m-chlorophenylhydrazone, abolished the intravesicular acidification. The acidification was not inhibited by 3 mM tetra-n-butylammonium. The initial rate of the H+ uptake was increased with a decrease in pH of the extravesicular medium, and the maximum rate was obtained at pH 5.5-5.6. It is concluded that H+ can be transported in place of Na+ by the sodium pump.

Adenosine Triphosphate↗
PubMed1986

The pyrogallol related compounds reduce UV-induced mutations in Escherichia coli B/r WP2.

Plant components with bio-antimutagenic activity were screened on UVC (254 nm)-induced mutagenesis using E. coli B/r WP2. The components with a pyrogallol moiety including gallic acid, (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG) reduced the mutation induction, but other components such as caffeic acid, chlorogenic acid and quercetin did not. The above compounds with a pyrogallol moiety were also effective on UVAB (295-400 nm)-induced mutagenesis, while they showed little effect on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutagenesis. As this bio-antimutagenic effect was not seen in the DNA excision-repair-deficient strains WP2s and ZA159, the activity by the above plant components might be based on the promotion of the excision-repair system in E. coli B/r WP2.

Escherichia coli↗
PubMed1986

Proton transport catalyzed by the sodium pump. Ouabain-sensitive ATPase activity and the phosphorylation of Na,K-ATPase in the absence of sodium ions.

The possibility that H+ might substitute for Na+ at Na+ sites of Na+,K+-ATPase was studied. Na+,K+-ATPase purified from pig kidney showed ouabain-sensitive K+-dependent ATPase activity in the absence of Na+ at acid pH (H+,K+-ATPase). The specific activity was 1.1 mumol Pi/mg/min at pH 5.7, whereas the specific activity of Na+,K+-ATPase was 14 mumol Pi/mg/min at pH 7.5. The enzyme was phosphorylated from ATP in the absence of Na+ at the acid pH. The initial rate of the phosphorylation was also accelerated at the acid pH in the absence of Na+, and the maximal rate obtained at pH 5.5 without Na+ was 9% of the rate at pH 7.0 with Na+. The phosphoenzyme was sensitive to K+ but almost insensitive to ADP. The phosphoenzyme was sensitive to hydroxylamine treatment and the alpha-subunit of the enzyme was found to be phosphorylated. H+,K+-ATPase was inhibited as effectively as Na+,K+-ATPase by N-ethylmaleimide but was less inhibited by oligomycin or dimethyl sulfoxide. These results indicate that protons have an Na+-like effect on the Na+ sites of Na+,K+-ATPase and suggest that protons can be transported by the sodium pump in place of Na+.

Adenosine Triphosphatases↗
PubMed1986

Characterization of ouabain-sensitive phosphatase activity in the absence of potassium ion in purified pig kidney Na,K-ATPase.

The ouabain-sensitive phosphatase activity of purified pig kidney Na,K-ATPase preparation in the absence of potassium ion ((-K)phosphatase) was examined precisely. During the preparation procedures, the (-K)3-O-methylfluoresceinphosphatase ((-K)3-OMFPase) activity or the (-K)p-nitrophenylphosphatase ((-K)pNPPase) activity appeared to be purified in parallel with the Na,K-ATPase activity. The (-K)phosphatase activity was competitively inhibited by ATP and by ADP, with the K1 values of 0.25 microM and 1.4 microM, respectively. These values are consistent with their Kd values for the high-affinity ATP binding site of the Na,K-ATPase (Hegyvary, C. & Post, R.L. (1971) J. Biol. Chem. 246, 5234-5240). The substrate, pNPP, apparently competed with covalently bound fluorescein-5'-isothiocyanate (FITC), which is known to bind in the neighborhood of the high-affinity ATP binding site of the Na,K-ATPase, in both the (-K)phosphatase and the (+K)phosphatase reactions. The FITC-fluorescence intensity of FITC-labeled enzyme at the maximal steady-state activity of the (-K)phosphatase reaction was at a similar level to that of the E2 species. However, the FITC-labeled enzyme in the presence of only magnesium ion or only pNPP gave a fluorescence level similar to that of the E1 species. Oligomycin inhibited the (-K)phosphatase activity by at most 46%. On the basis of these results, it is strongly suggested that the (-K)phosphatase reaction is catalyzed at the high-affinity ATP binding site of Na,K-ATPase, and the (-K)phosphatase reaction proceeds in a cyclic manner (E1----E2----E1).

Animals↗