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Biomedical subjects

K Miyai

Publications and source records attributed to K Miyai.

At least 163 records · Page 9Linked to original sources
PubMed1988

Increase in peripheral large granular lymphocytes in postpartum autoimmune thyroiditis.

In order to elucidate the mechanism of postpartum aggravation of autoimmune thyroid disease (AITD), we serially examined the change in the proportion of peripheral large granular lymphocytes (LGL), which have activities of NK, K and/or cytotoxic T cells, in their postpartum period. Within 6 months postpartum, the percentage of LGL increased transiently in patients with AITD who remained euthyroid, or developed destructive thyrotoxicosis and/or hypothyroidism due to thyroiditis and even in normal controls. These changes in the LGL percentage were more obvious in the patients who had marked postpartum thyroid dysfunction. In contrast, we did not find a definite increase in the LGL percentage within 6 months postpartum in patients with Graves' disease who relapsed into Graves' thyrotoxicosis. These deta suggest that the increase in LGL in the postpartum period may be related to the induction of postpartum destructive thyrotoxicosis and/or hypothyroidism in AITD.

Female↗
PubMed1988

Serum free thyrotropin subunit in congenital isolated thyrotropin deficiency.

In two patients with congenital isolated thyrotropin (TSH) deficiency, serum TSH determined by a sensitive immunoradiometric assay (IRMA) was consistently undetectable. The basal levels of serum free TSH-alpha subunit (TSH-alpha) determined by a specific radioimmunoassay (RIA) were elevated in the hypothyroid state, and decreased to the undectable level during displacement therapy with thyroid hormone. The serum free TSH-alpha significantly increased following intravenous administration of thyrotropin releasing hormone (TRH). Serum free TSH-beta subunit (TSH-beta) was undectable. These findings suggest that TSH deficiency in this disease is not due to absence of thyrotroph in the pituitary gland or deficiency of TSH-alpha, but to abnormalities of the TSH-beta gene.

Adult↗
PubMed1988

Protein C in human plasma determined by homogeneous enzyme immunoassay with use of a centrifugal analyzer.

We describe the simple and rapid enzyme immunoassay of protein C in human plasma with use of a Cobas Fara centrifugal analyzer. The antibody, labeled with horseradish peroxidase, is reacted with antigen (protein C) for 15 min. The peroxidase activity of the resulting antigen-antibody conjugate is measured at 500 nm for 5 min in the presence of excess H2O2, phenol, and 4-aminoantipyrine, as compared with that of free conjugates. Results are calculated from a stored standard curve and expressed as a percentage of the value determined for a pooled specimen of normal adult plasma. The standard curve is linear from 0% to 200%. The CV is generally less than 4% for different concentrations of protein C. In liver cirrhosis, hepatocellular carcinoma, therapy with warfarin, thrombosis, and disseminated intravascular coagulation, protein C concentrations are about 40-70% of normal. Results obtained with the present homogeneous enzyme immunoassay correlated well with those by enzyme-labeled immunosorbent assay (r = 0.97).

Adult↗
PubMed1988

Morning sickness and thyroid function in normal pregnancy.

Thyroid function in early normal pregnancy was evaluated with reference to morning sickness using a newly developed free thyroxine (T4) radioimmunoassay and a highly sensitive TSH immunoradiometric assay. A significant increase in serum free T4 and a decrease in serum TSH were observed in early pregnancy relative to the levels in nonpregnant controls. The increased free T4 and hCG and decreased TSH correlated with the severity of morning sickness, and these changes were especially marked in subjects with nausea and vomiting. The individual serum levels of hCG in the pregnant group correlated significantly, directly with the levels of free T4 and inversely with those of TSH. The increased free T4 and decreased TSH in subjects with emesis returned to the normal ranges of nonpregnant controls after improvement of emesis. These data indicate that the thyroid gland is physiologically activated in early pregnancy, possibly by hCG or a related substance, which may induce gestational emesis. On the other hand, an increased level of free T4 and a reduced level of TSH in early normal pregnancy are not indications of thyrotoxicosis and may not necessitate antithyroid drug treatment.

Analysis of Variance↗
PubMed1987

Production of human thyroid-stimulating hormone in Chinese hamster ovary cells.

Human thyroid-stimulating hormone (hTSH) has been produced in Chinese hamster ovary (CHO) cells co-transformed with two plasmids: one carrying the alpha subunit cDNA with mouse dihydrofolate reductase gene and the other carrying hTSH beta subunit cDNA. Each cDNA was driven to expression under the control of SV40 early promoter. hTSH and its alpha subunit were secreted into culture media, and their secretion increased with exposure of the cells to increasing concentrations of methotrexate. Gel filtration analysis revealed that the molecular size of the hTSH was the same as that of natural hTSH. Furthermore, the CHO cell-produced hTSH elevated the cyclic AMP level in the rat thyroid cell line FRTL-5 in the same manner as natural hTSH does.

Animals↗
PubMed1987

A new type of albumin with predominantly increased binding affinity for 3,3',5-triiodothyronine in a patient with Graves' disease.

A new type of serum albumin, that shows a markedly enhanced binding activity for 3,3', 5-triiodothyronine (T3), a somewhat increased activity for thyroxine (T4), and a normal activity for 3,3', 5-triiodothyronine (rT3) is described. This albumin was found in a patient with Graves' disease. After successful subtotal thyroidectomy, the existence of abnormal binding activity for T3 was suspected in this patient because of persistently increased total T3 concentrations in spite of elevated thyrotropin levels. Although free T3 and T4 concentrations measured by radioimmunoassay using commercial tracer analogue kits were markedly increased, those measured by equilibrium dialysis were within normal ranges. Electrophoretic studies revealed that these abnormalities were due to the markedly increased T3 binding activity by the serum albumin; that for T4 was also slightly increased. Scatchard plot analysis revealed that the association constant (Ka) for T3 of the patient's albumin was 5.1 X 10(6)/M (normal pooled albumin; 6.2 X 10(5)/M), and those for T4 and rT3 were 5.2 X 10(6)/M and 2.7 X 10(6)/M, respectively (normal pooled albumin; 2.1 X 10(6)/M for both T4 and rT3). The increased binding of albumin to T3 and T4 was markedly inhibited by barbitone, and 8-anilino-1-naphthalene-sulfonic acid. These characteristic features, and erroneously high values of free T3 and T4 concentrations measured by tracer analogue kits were similar to those seen in patients with familial dysalbuminemic hyperthyroxinemia, which have been previously reported. These findings strongly suggest that this albumin is a new variant in various dysalbuminemic syndromes, and the abnormal binding of iodothyronines moieties in these syndromes are not biochemically identical.

Adult↗