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Biomedical subjects

K Kushima

Publications and source records attributed to K Kushima.

At least 37 records · Page 2Linked to original sources

[Reevaluation of serum TSH determination in various pituitary disorders using highly sensitive immunoradiometric assay].

In thirty-one patients with various pituitary disorders, their serum TSH levels were reevaluated using two kinds of highly sensitive immunoradiometric assays (IRMAs). TSH levels were measured by radioimmunoassay (RIA) supplied by Daiichi Radioisotope Laboratory and the IRMAs, which were RIA-gnost TSH Ultrasensitive and SUCROSEP TSH IRMA using two types of monoclonal antibodies. The sensitivities of them were 0.08 and 0.1 microU/ml, respectively. Free thyroxine and free triiodothyronine levels were measured by RIAs (Amerlex kits). There was a significant correlation between basal TSH levels and the maximum increase in serum TSH above baseline using the RIA and the IRMAs when responses to TRH (500 micrograms i.v.) was determined, but no correlation between basal TSH and thyroid free hormone levels. In their TRH tests, three patients showed absent responses to TRH which were measured by the RIA, although by the IRMAs slight responses were observed. In two patients, exaggerated responses to TRH were observed and the increase of TSH levels measured by the IRMAs showed 143 approximately 210% higher than that of the RIA. The IRMAs were able to handle their peak levels time in all the patients with responses, however, in some patients the RIA was not sensitive enough to distinguish it. These results indicated that measurement of TSH levels by the IRMAs might be useful in the evaluation of the TSH secretion capacity in patients with various pituitary disorders.

Humans↗

[Hyperthyroidism due to a TSH-secreting pituitary tumor].

A 28-year-old female with a 12-year history of goiter is presented. She had both clinical and laboratory evidence of hyperthyroidism, and her serum TSH was persistently and markedly elevated after treatment with antithyroid drugs. A TRH stimulation test resulted in no further rise in serum TSH after cessation of medication. Menses were regular and serum prolactin levels were normal. Serum LH and FSH responses to LHRH stimulation test were normal. No other evidence of pituitary or peripheral endocrine deficiencies existed. She underwent a subtotal thyroidectomy followed by 131I therapy three years later. A pituitary adenoma with sphenoidal and suprasellar extension was completely removed by transphenoidal approach. On light microscopy, it was mostly composed of chromophobic cells with occasional calcification showing sinusoidal pattern. On electron microscopy, most of the cells contained fine granules, which suggested thyrotroph. The immunoperoxidase technique revealed TSH beta in the cytoplasm of some adenoma cells. Three days postoperatively the patient's serum TSH levels returned to normal. TRH stimulation test produced a normal response in serum TSH. The patient was diagnosed hypothyroid by laboratory findings and is currently on thyroid replacement therapy. The patient became pregnant and delivered twice prior to the operation for pituitary adenoma. The previously reported TSH secreting adenomas associated with hyperthyroidism were reviewed.

Adenoma↗

Epithelioid granuloma formation requiring no T-cell function.

Muramyl dipeptide (MDP), a minimal structure in bacterial cell walls essential for their adjuvant activity, was incorporated in a water-in-oil emulsion and injected into the footpads of nude rats devoid of functional T cells. MDP thus injected evoked massive epithelioid granulomas in the draining lymph nodes, indicating that MDP induced epithelioid granuloma formation requires no T cells. This finding with other data available strongly suggest that epithelioid granulomas can be induced without immunologic reactions.

Acetylmuramyl-Alanyl-Isoglutamine↗

Extraction and purification of a substance with luteinizing hormone releasing activity from the leaves of Avena sativa.

Attempts were made to purify the LH-releasing substance extracted from the leaves of Avena sativa by means of two-step chromatographic procedures using a weakly acidic ion-exchange resin (CG-50,type II) and DEAE-Sephadex A-25 (coarse) with successful results. For preliminary fractionation of such starting materials as dried leaves, fresh leaves, and acetone-extracted powder(crude extracts), 5% acetate-buffered active carbon proved to be more effective than starch zone electrophoresis. From its behavior on chromatography with weakly acidic ion-exchange resins as well as Sephadex gel filtration, the active fraction extracted from the leaves of Avena saliva was assumed to be different from the LH-RH present in the hypothalamus. This partially purified material, however, was demonstrated to have an LH-releasing activity by the ovarian ascorbic acid depletion method using Wistar-Imamichi strain rats. Evidence was presented that its site of action is in the adenohypophysis.

Animals↗