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Biomedical subjects

K Ohshima

Publications and source records attributed to K Ohshima.

At least 415 records · Page 23Linked to original sources

Changes in the multiple components of rat pituitary TSH and TSH beta subunit following thyroidectomy.

Heterogeneity of pituitary TSH was investigated in rats following thyroidectomy. Adult male rats were sacrificed at varying periods (2-28 days) after thyroidectomy. In another experiment, thyroidectomized rats were injected daily with various doses of L-T4 (0.3-7.5 micrograms/100 g body weight, ip) and sacrificed 2 weeks later. The homogenate of the pituitaries was applied on an isoelectric focusing column or a Sephacryl S-200 column. The normal rat pituitary contained 5 major components of immunoreactive (IR) TSH in isoelectric focusing, in which the isoelectric point (pI) ranged from 6.6 to 8.8. The multiple components of IR-TSH beta were observed almost in the same areas as those of IR-TSH. Following thyroidectomy IR-TSH components with more acidic pI, associated with IR-TSH beta, were evident. A large amount of IR-TSH beta in the pituitaries of thyroidectomized rats appeared near the void volume in gel filtration, suggesting the presence of big TSH beta. Supplement of L-T4 minimized these thyroidectomy-induced changes in isoelectric focusing and gel filtration. Furthermore, big IR-TSH beta was little affected by ultracentrifugation and was relatively stable after treatment with 6 M guanidine hydrochloride. We demonstrated that the rat pituitary gland contained multiple components of IR-TSH and IR-TSH beta, both of which became variegated after thyroidectomy. It is suggested that a discernible degree of heterogeneity of TSH, particularly of TSH beta, is dependent upon the increased rate of TSH biosynthesis at the pituitary level.

Animals↗

Muscle protein turnover in the perfused hindquarters of lean and genetically obese-diabetic (db/db) mice.

The stability of the perfused mouse hindquarter was assessed for a period of 5 h, and the preparation shown to remain stable for metabolic studies over this time period. Muscle protein synthesis and degradation rates in lean and diabetic-obese (db/db) mice were measured using the in situ perfused hindquarter preparation. The rates of protein synthesis were 48% lower in the muscles of intact db/db mice than in the lean controls when expressed per gram TCA precipitable protein and 46% lower when expressed per gram dry weight. Adrenalectomy, which has been shown to restore the lean body mass of the db/db mice to normal, had the effect of returning protein synthesis rate in muscle of db/db mice to lean control values. Insulin at a dose of 1 mU/ml stimulated protein synthesis in lean mice only, showing that the process of protein synthesis in the db/db mice is also insensitive to insulin. Measurements of the rates of degradation of muscle protein showed no differences between lean and db/db mice. These findings suggest that the decreased lean body mass of db/db mice is the result of a defect in protein synthesis rather than due to altered degradation.

Adrenalectomy↗

Benzethonium chloride resistance in Pseudomonas aeruginosa isolated from clinical lesions.

The benzethonium chloride resistance of 341 strains of Pseudomonas aeruginosa isolated from Jikei University Hospital was determined. The distribution pattern of the susceptibility to benzethonium chloride clearly revealed two peaks, and the resistance was differentiated by 1000 micrograms/ml (0.1%) of benzethonium chloride. The frequency of resistance to benzethonium chloride was 51.6%. Furthermore, the frequencies of resistance to SM, TC, CP, KM, GM, PIP, Hg, Cd, As and chlorhexidine were 42.5, 15.8, 41.3, 29.6, 14.0, 8.2, 88.3, 97.9, 97.1, and 74.5%, respectively.

Anti-Bacterial Agents↗

Atypical nervous lesion in Haemophilus somnus infection of cattle.

Two cows affected with Haemophilus somnus were examined pathologically. Although manifested lesions were composed of fibrinopurulent meningitis without the usual parenchymatous lesions in the central nervous system, Haemophilus somnus was isolated in pure culture from the cerebral cortex of both cases. Presence of this atypical lesion in the nervous system should be kept in mind for the differential diagnosis of the disease.

Animals↗

Survey of resistance to metals and volatilization activity of Hg-resistant R plasmids in Citrobacter isolated from clinical lesions in Japan.

Clinical isolates of Citrobacter (277 strains) were studied for the resistance to four metals and four drugs. The distribution patterns of their susceptibility to Hg, Cd and As clearly revealed two peaks, but only a single peak of resistance to Pb. The frequencies of resistance to Hg, Cd, As, SM, TC, CP and KM were 31.8, 94.2, 57.8, 51.3, 44.8, 35.7 and 28.9%, respectively. And we selected 88 mercury resistant strains, and they were tested for their ability to transfer the resistance to the mercury and drug sensitive recipients of E. coli K12-ML1410-Nx and E. coli JE17-Rif. Among 88 strains of Hg resistant Citrobacter, 80 R plasmids with Hg resistance could be demonstrated. It should be noted that transferable R plasmids with Hg resistance were demonstrated in 91% of the Hg-resistant isolates. Furthermore, we tested the volatilization of mercury by strains containing these mercury resistance plasmids, by using radioactive 203Hg2+. All of these isolates of Citrobacter have volatilization activity of Hg2+. Also, all of these volatilization activity is inducible.

Anti-Bacterial Agents↗

Functional morphology of the pineal gland in young chickens.

One and two-month-old chickens were killed at mid light and mid dark under the experimental photoperiod (LD 12: 12). The pineal glands of the young chickens are composed of parenchymal cells and large follicles, presenting a tubulofollicular arrangement. The sensory-like pinealocytes are pear-shaped and have a cilium with 9 + 0 axial configuration projecting into the lumen. Their cytoplasm has cell organelles, small granulated vesicles about 100 nm in diameter and synaptic ribbons. The concentric lamellar complexes like myelin sheaths are frequently observed in the follicular lumen. The secretory-like supporting cells have irregular-shaped microvilli and some granulated vesicles about 200 nm in diameter in the vicinity of the apical surfaces. Occasionally, a few nerve cells are found in the pineal parenchyma. It was found that the sensory-like pinealocytes of the young chickens have many mitochondria, well-developed Golgi complexes and large lysosomes in solid type in the light period, whereas they have a few cell organelles and somewhat smaller rod-like lysosomes with some vacuoles in the dark period. On the other hand, the sensory-like pinealocytes have more synaptic ribbons in the dark period than in the light period.

Animals↗

[Evaluation of prognostic factors in hepatocellular carcinoma using multiple regression analysis].

We analysed the relationship between 19 prognostic factors and the life span of patients with hepatocellular carcinoma. Among 52 patients who had been admitted to the Gifu Prefectural Gifu Hospital, in 46 the pathological diagnosis was confirmed. We selected 9 of 19 variables by the stepwise forward regression method. These were Arels Classification, ascites, HBsAg, performance status, method of therapy, sex, GOT, albumin and bilirubin. Results of multiple regression analysis demonstrated that the presence of ascites is the most important factor; other significant factors are Ariel's Classification, performance status, positivity of HBsAg, method of therapy, and GOT. These parameters were paralleled with the survival curves, most of which had been categorized. Although intra-arterial infusion of ADM was considered the most favourable treatment method, the survival curves suggested that other methods were equally effective.

Adult↗

TSH and prolactin secretions in Hashimoto's thyroiditis following withdrawal of thyroid hormone therapy.

Changes in the pituitary-thyroid axis in patients with Hashimoto's thyroiditis following withdrawal of thyroid suppressive therapy were analyzed. The group of patients with thyroid adenoma served as control (group I). Patients with Hashimoto's thyroiditis were divided into 2 groups on the basis of serum TSH levels 8 weeks after discontinuing the exogenous thyroid hormone (group II, less than 10 microunits/ml; group III, more than 10 microunits/ml). During treatment with L-T4(200 micrograms/day) or L-T3(50 micrograms/day), there was no significant difference in serum T4-I and T3 levels among the three groups. Following L-T4 withdrawal, basal serum TSH levels were higher at 2 to 8 weeks in groups II and III than in group I. Serum TSH response to TRH was greater at 4 to 8 weeks in groups II and III than in group I. Following L-T3 withdrawal, basal serum TSH levels were higher at 1 and 2 weeks in group II than in group I, while those of group III were consistently higher during the study. Higher TSH responses to TRH were observed at 1 to 8 weeks in groups II and III. Neither basal nor TRH-induced prolactin (PRL) secretion differed significantly among the three groups. We have demonstrated that pituitary TSH secretion in patients with Hashimoto's thyroiditis is affected more by withdrawal of thyroid hormone therapy than in patients with thyroid adenoma. In addition, the present findings suggest a difference between the sensitivity of thyrotrophs and lactotrophs in Hashimoto's thyroiditis after prolonged thyroid therapy is discontinued.

Adenoma↗