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S Sakata

Publications and source records attributed to S Sakata.

At least 253 records · Page 14Linked to original sources
PubMed1986

An improved and simplified method for the detection of thyroid hormone autoantibodies (THAA) in serum.

We have developed and evaluated a new and simplified method for the detection of thyroid hormone autoantibodies (THAA) in serum. The method includes acidification of serum followed by adsorption of liberated thyroid hormones onto dextran-coated charcoal and then alkalinisation of the serum in assay buffer prior to performing a binding study. Using our method, specific binding of 125I-T4 to serum THAA in two patients with Hashimoto's thyroiditis was almost the same regardless of whether or not the sera had been preincubated with a large amount of cold T4. On the other hand, without the acid treatment, preincubation with cold T4 considerably inhibited the binding of 125I-T4 to serum THAA in both cases. These results indicate that serum THAA can be easily detected under conditions in which circulating thyroid hormones hardly affect the binding study by using our new sensitive method.

Autoantibodies↗
PubMed1986

Thyroid hormone autoantibodies (THAA) in two cases of Graves' disease: effects of antithyroid drugs, prednisolone, and subtotal thyroidectomy.

Changes in titers of serum thyroid hormone autoantibodies (THAA) and anti-thyroglobulin (Tg) antibodies during treatment with antithyroid drugs (methimazole and propylthiouracil) were examined in two cases of Graves' disease. Effects of prednisolone and subtotal thyroidectomy were also investigated in one case (case 1). Initially both cases had only anti-T4 autoantibodies in their serum. During methimazole therapy, the titer of anti-T4 autoantibodies increased in both cases, and anti-T3 autoantibodies became detectable and their titer increased in case 2. The influence of propylthiouracil on the titer of THAA was not clear. Both prednisolone plus methimazole therapy and subtotal thyroidectomy decreased the level of anti-T4 autoantibodies in case 1. There was a significant correlation between titers of THAA and anti-Tg antibodies in both cases, although titers of anti-Tg antibodies in case 1 stayed within the normal range throughout the investigation period. These results indicate that methimazole treatment could induce and/or enhance the production of THAA and THAA are antibodies against thyroid hormone-containing Tg molecule.

Autoantibodies↗
PubMed1986

The effect of double filtration plasmapheresis on thyroid hormone economy and thyroid function.

Five cases of rheumatoid arthritis (RA), two cases of systemic lupus erythematosus (SLE), a case of mixed connective tissue disease (MCTD), and a case of cold urticaria were treated with double filtration plasmapheresis (DFP). Each aliquot of plasma was obtained at three different points of the DEP circuit during the treatment and concentrations of thyroid hormones as well as thyroxine binding globulin (TBG) were measured. Despite the removal of considerable amounts of triiodothyronine (T3), thyroxine (T4), and TBG from the plasma, levels of plasma free T3 (FT3) and free T4 (FT4) before and immediately after DFP treatment were not significantly different. These results indicate that DEP therapy rarely affects plasma concentration of active thyroid hormones in patients who undergo such therapy.

Adolescent↗
PubMed1986

Familiar hypercholinesterasemia. A case report.

A 58-year-old female who had a serum cholinesterase activity four times higher than normal is described. Investigation of her family revealed that five out of seven tested had high level of serum cholinesterase activity. The family distribution of the increased cholinesterase suggests that the inheritance is transmitted in a autosomal dominant manner. Analysis of the isoenzyme of serum cholinesterase of five cases including the patient showed that none of them had extracomponent (C5) of the cholinesterase. Examination of anti-cholinesterase antibodies in her serum was negative. Molecular weight of her serum cholinesterase by HPLC analysis was not different from that of a healthy subject. It was speculated that the overproduction of usual components (C1, C2, C3, C4), decreased clearance of cholinesterase by a certain mechanism(s), and/or the presence of cholinesterase which has more active catalysis could be responsible for her and her family's hypercholinesterasemia.

Cholinesterases↗
PubMed1986

Incubation procedure effective for decreasing oxygen affinity of red cells in the dog.

Because oxygen affinity of canine red cells had been hardly reduced by the conventional procedure of incubation with inosine-pyruvate-phosphate or dihydroxyacetone-pyruvate-phosphate, incubation with acidified phosphoenolpyruvate (PEP) medium was tested for its effect on oxygen affinity. As this procedure had been shown to induce a significant increase of 2,3-diphosphoglycerate (DPG) in human red cells, it was also proved to be effective for lowering oxygen affinity of canine red cells. Incubation with 15 mM PEP in ACD medium (pH 6.0) at 37 degrees C for 30 min was the standard procedure established after critical scrutiny. The incubated blood exhibited an average increase in half-saturation pressure (P50) amounting to 7 Torr (pH 7.40, Pco2 40 Torr, 37 degrees C), with no appreciable hemolysis and little change in mean corpuscular hemoglobin concentration. Results with Dowex 1-X8 anion exchange chromatography of acid soluble phosphates from the incubated red cells suggested that PEP penetrated rapidly through the canine red cell membrane and was metabolized to DPG via the retrograde process of the Embden-Meyerhof glycolytic pathway.

2,3-Diphosphoglycerate↗
PubMed1986

Structural and functional characterization of a canine minor glycosylated hemoglobin, Hb Can AIc.

Structural and functional studies of minor glycosylated hemoglobins in non-human mammals have been very few. Therefore, we attempted further characterization of a canine glycosylated hemoglobin (tentatively designated as Hb Can AIc) which had been isolated by Bio-Rex 70 chromatography (Enoki, Y. et al. (1982) Hemoglobin 6, 143-151). After isolation of the constituent subunits by hybridization-mercuration technique, we found by peptide mapping that the structural modification was confined in amino-termini of the beta subunits in which glycosyl ketoamine linkage was also shown to be localized by thiobarbituric acid reaction. Compared with the major hemoglobin (Hb Can A0), Hb Can AIc was characterized by such functional properties as a slightly lower oxygen affinity and a markedly reduced response to the allosteric effects of carbon dioxide and organic phosphates. The anion and H+ Bohr effects were not different from those in Hb Can A0. All these facts support that this hemoglobin is a canine counterpart of Hb AIc.

Amino Acids↗
PubMed1986

Concentrations of free thyroxine, total thyroxine, and total triiodothyronine in rabbits immunized with human thyroglobulin.

Levels of serum free thyroxine, total triiodothyronine and total thyroxine were measured in two rabbits (TG-1, TG-2) which had been immunized with human thyroglobulin and produced both anti-thyroglobulin and anti-thyroid hormone antibodies. Despite the presence of both anti-triiodothyronine and -thyroxine antibodies, levels of serum free thyroxine in serial sera obtained from a rabbit (TG-1) stayed within normal range up to 249 days after the first immunization, whereas in the other rabbit (TG-2), serum free thyroxine concentrations of serial sera declined after three immunizations and stayed at lower levels than normal range up to 249 days. Extraction of serial sera from both rabbits disclosed the presence of larger amounts of triiodothyronine and thyroxine in immune sera than preimmune sera. From these results, it is concluded that the presence of anti-thyroid hormone antibodies per se can reduce serum level of free thyroxine in rabbits.

Animals↗
PubMed1986

Effect of anti-insulin antibodies on glycemic control in insulin treated diabetic patients.

In order to examine the effect of anti-insulin antibodies on serum insulin concentration and glycemic control, sera from 49 insulin-treated diabetic patients (20 males and 29 females) were examined for their titer of anti-insulin antibodies, and concentrations of total insulin (TIRI), free insulin (FIRI) and hemoglobin A1c. Titer of anti-insulin antibodies correlated only with TIRI (r = 0.72, p less than 0.001) and did not correlate with duration of insulin treatment, FIRI concentration, daily dose of insulin, or HbA1c concentration. These results indicate that elevated titer of anti-insulin antibodies in patients under insulin therapy, increases total serum insulin concentration but does not affect serum free insulin level, and has little effect, if any, on glycemic control and the required daily dose of insulin.

Adult↗
PubMed1986

Genetic control of the production of anti-thyroid hormone antibodies in mice immunized with human thyroglobulin.

Various strains of mice with different H-2 and Igh-I allotypes were immunized with human thyroglobulin (HTg) and genetic control of the production of anti-thyroid hormone antibodies was examined. Anti-HTg antisera obtained from different strains of mice were examined for the presence of anti-thyroid hormone antibodies. At least one Ir-gene which controls the production of anti-T4 antibodies by immunization with HTg was identified in the I-A subregion. The presence of Ir-genes outside the H-2 was also suspected. Concerning the production of anti-T3 antibodies, only three strains (B10.A, C3H.SW, BALB/cJ) were high responders and therefore we were unable to identify the Ir-gene for them. These results indicate the presence of Ir-gene which controls the immune response in mice against thyroid hormone and suggest that the anti-thyroid hormone antibodies observed in various thyroidal and non-thyroidal disorders could be anti-HTg antibodies. The significance of genetic control of the production of anti-thyroid hormone antibodies in mice immunized with HTg is discussed.

Animals↗
PubMed1986

[SPECT images using a multislice fan beam collimator].

Several methods to improve the image resolution of single photon emission computed tomography (SPECT) occur to us. It is one method to use multislice fan beam collimators which have the parallel collimation along the cephalic-caudul axis of a patient and the conversing collimation within planes parpendicular to that axis. It is impossible to obtain corrective image when we used the algorithm which is commonly used for reconstruction of SPECT images. We proposed a reconstruction algorithm for multislice fan beam collimator in this paper. An interpolation method developed for fan beam type X-ray CT was modified to reconstruct images from SPECT with multislice fan beam collimator. This algorithm was confirmed by means of computer simulation studies. Beside improving the system resolution by effectively reducing the intrinsic resolution of the cameras, this collimator also increases the system sensitivity by utilizing a large fraction of the crystal area. We have thought that to use multislice fan beam collimator is beneficial for SPECT images.

Tomography, Emission-Computed↗
PubMed1985

[Investigations on the mechanism(s) of the production of anti-thyroid hormone antibodies 4: the effect of adjuvant on the immune response to human thyroglobulin].

Forty-five female DDYK mice were divided into three groups and immunized with different preparations of human thyroglobulin (HTg). Group 1 mice were immunized subcutaneously in the back with HTg emulsified with FCA. Group 2 mice were immunized subcutaneously in the back with HTg dissolved in PBS. Group 3 mice were immunized with HTg dissolved in PBS and FCA separately in the right (HTg) and left (FCA) of the back. After the fourth immunization (45 days after the first immunization), antisera as well as thyroid glands were obtained, and titers of anti-HTg, anti-T3, anti-T4 and the presence of lesions of autoimmune thyroiditis were examined. In group 1 mice, titers of anti-HTg and anti-T4 antibodies were significantly higher than those of the other two groups, whereas titers of anti-T3 antibodies were significantly lower than those of the other two groups. In group 1 mice, a significant correlation between titers of anti-T3 and anti-T4 antibodies was observed, whereas in group 2 and group 3 mice, no such correlation was observed. The incidence of lesions of autoimmune thyroiditis was significantly higher in group 2 and group 3 mice than in group 1 mice. Thus emulsification of HTg with FCA had inhibitory effects on the induction of experimental thyroiditis in mice immunized with HTg. These results indicate the possibility that FCA has a modulatory effect both quantitatively and qualitatively on the immune response against HTg in mice.

Animals↗
PubMed1985

In vitro erythropoietin assay based on erythroid colony formation in fetal mouse liver cell culture.

Critical studies were made on erythroid colony formation from cultured fetal mouse liver cells in an attempt to develop a simple and sensitive erythropoietin (Epo) assay procedure. The maximum colony formation was observed 24 h after plating of the cells when an evident dose-response relation was found for Epo added. The colony forming ability decreased steadily as the gestational age of the fetus advanced and was gradually lost by postnatal days 10-11. By morphological and cytochemical criteria almost all the colonies were found to be erythroid. 59Fe-labelling experiments revealed a fairly good correlation between the colony number and 59Fe incorporation into both cells and haem. Dose-response curves for plasma were parallel to the Epo standard curve. Based on these findings we developed a procedure which could measure as little as 0.4 mU of Epo without requiring 59Fe. Using this method, plasma Epo titres were determined in 16 normal and 69 anaemic subjects.

Animals↗
PubMed1985

Monoclonal antibodies to thyroglobulin elucidate differences in protein structure of thyroglobulin in healthy individuals and those with papillary adenocarcinoma.

Monoclonal antibodies specific for human thyroglobulin (Tg) from normal subjects were prepared by the hybridoma technique. Antibodies from three clones (clones B2F, C6E, and C6G) were found to produce linear Scatchard plots, as predicted for homogeneous antibodies. Based on different patterns of cross-reactivity with Tg from various species, these monoclonal antibodies recognized different determinants on the Tg molecule. Moreover, antibodies from clone B2F bound simultaneously with clone C6E or C6G to Tg. Therefore, antibody from clone B2F must bind to a site on Tg distant from those recognized by clone C6E or C6G. The monoclonal antibodies C6G and C6E bound almost equally to normal Tg and Tg from patients with Graves' disease, adenoma, follicular carcinoma, and papillary adenocarcinoma. In contrast, whereas clone B2F bound equally well to normal Tg and Tg from patients with Graves' disease, adenoma, and follicular carcinoma, this clone bound poorly to Tg from patients with papillary adenocarcinoma. Since the binding activity of clone B2F for unfolded or degenerated Tg was remarkably decreased, these differences in binding activities to native Tg may reflect changes in conformation of the Tg molecule. Thus, the results indicate there may be conformational changes in Tg from patients with different thyroid diseases.

Adenocarcinoma, Papillary↗