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Biomedical subjects

M Miyakawa

Publications and source records attributed to M Miyakawa.

At least 19 recordsLinked to original sources
PubMed1992

Endothelin-1 stimulates c-fos mRNA expression and acts as a modulator on cell proliferation of rat FRTL5 thyroid cells.

In FRTL5 thyroid cells, endothelin (ET)-1 alone had no effect on DNA synthesis but caused a transient increase in c-fos mRNA levels and stimulated IGF-I induced DNA synthesis and cell proliferation. By contrast, ET-1 inhibited the stimulatory effects of TSH actions on DNA synthesis, cell proliferation and c-AMP production. 8-Bromo-cAMP-induced DNA synthesis was also inhibited by ET-1, suggesting that ET-1 exerts its inhibitory effects at step(s) involving cAMP production and post cAMP pathway. ET-1-induced suppression of TSH actions were reversed by a C-kinase inhibitor, H-7. These results suggest that the effect of ET on functions of FRTL5 cells is, at least, in part mediated by C-kinase dependent pathway.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

Myasthenia gravis with thymoma associated with occult thyroid carcinoma.

We report herein a case of myasthenia gravis associated with thymoma and occult thyroid carcinoma with metastasis to a cervical lymph node, which was treated in two stages by a total thymectomy and radical dissection of the bilateral neck after a total thyroidectomy. A 48 year old woman was admitted with right blepharoptosis and hypodynamia of the proximal muscles. After various examinations, a diagnosis of myasthenia gravis was made. The association of thymoma was clarified upon CT scanning and a total thymectomy performed. However, after surgery, swelling of the cervical lymph nodes became apparent and a biopsy revealed metastasis of thyroid carcinoma in the lymph nodes. A diagnosis of occult thyroid carcinoma with metastasis to a cervical lymph node was subsequently made and a total thyroidectomy and radical dissection of the bilateral neck performed 37 days after the total thymectomy. The patient's postoperative course was uneventful and for the time being, no recurrence is expected. It is considered better to perform two-stage operations for easier and safer postoperative management when myasthenia gravis associated with occult thyroid carcinoma is treated, although it depends on the development of thyroid carcinoma being occult.

Female↗
PubMed1992

Thyroid ultrasonography related to clinical and laboratory findings in patients with silent thyroiditis.

We summarized the clinical course of 10 patients with silent thyroiditis and evaluated the clinical usefulness of ultrasonography, in combination with clinical and laboratory findings, for the differentiation from Graves' disease. Serum T3 and T4 were increased in all cases, and the ratio of T3/T4 (ng/micrograms) was 17.8 +/- 3.6 (SD). But in 3 of 10 patients the ratio was greater that 20. TSH receptor antibody (TRAb) and thyroid stimulating antibody (TSAb) were negative in all cases. The estimated thyroid volume by ultrasonography was 18.4 +/- 5.5 ml, which was slightly increased but significantly lower than those in Graves' disease (p less than 0.05). The internal texture of the thyroid showed a decreased echogenicity with a mean echo level of 70.4 +/- 15.4. There was a weak positive correlation between the echo level at the onset of thyrotoxicosis and the lowest T3 level during the clinical course (p less than 0.05). It is suggested that ultrasonography gives a useful information to the diagnosis and outcome of patients with silent thyroiditis.

Adult↗
PubMed1992

Ectopic aberrant adrenals with epididymal abnormality.

We report a rare case of ectopic aberrant adrenals associated with epididymal abnormality found during exploration for a left undescended testis. Two ectopic adrenals were found, one on the epididymis and the other adjacent to the spermatic cord. We believe the simultaneous occurrence of epididymal abnormality and ectopic aberrant adrenals has not been reported before.

Adrenal Glands↗
PubMed1992

A thymocytotoxic autoantibody reacts with the mouse brain cells in culture.

Autoimmune-prone New Zealand Black mice produce a large amount of autoantibodies cytotoxic for thymocytes (natural thymocytotoxic autoantibodies, NTA). A monoclonal NTA (NTA260) has been found to react with brain tissues as well as the cell surface of thymocytes. We investigated the expression of NTA 260 antigen in the primary culture of fetal brain cells. NTA260 labeled strongly the cytoplasm of nerve cells after fixation, but failed to stain the living cells. Western blot analysis revealed that NTA260 recognized predominantly a band at approximately 53 kDa in brain and thymic extracts. These findings indicate that neuronal NTA260 antigen, which has a molecular mass similar to that of thymocytes, is likely an intracellular component.

Animals↗
PubMed1992

Alcohol-related problems encountered by Japanese, Caucasians, and Japanese-Americans.

Using population-based survey data, personal-problematic and socioproblematic factors were examined among Japanese in Japan, Japanese-Americans in Hawaii, and Japanese-Americans; Caucasians in California were analyzed as a control group. Caucasian males were more likely to exhibit drinking-related social problems, whereas Japanese males showed more personal-problematic symptoms. Japanese-American men, both in Hawaii and California, were least likely among the three ethnic groups to have personal-problematic symptoms and were more likely to have socioproblematic symptoms than Japanese men. These differences might be explained by differences in the perception of social problems.

Adult↗
PubMed1992

Estimating a summarized odds ratio whilst eliminating publication bias in meta-analysis.

Publication bias is a recognized phenomenon, i.e. studies with statistically significant results are more likely to be published than those finding no difference between the groups studied. Summarized odds ratio calculated from odds ratios of published studies in a meta-analysis may be overestimated because of publication bias. This is a significant problem in research areas involving weak associations between causes and results. The magnitude of publication bias in a given research area cannot be determined directly. The present study enables us to calculate the summarized odds ratio of hypothetical unpublished studies from odds ratios of published studies indirectly, employing a moment method by assuming the natural logarithm value of the odds ratio to be distributed normally. We can then estimate summarized odds ratio in all studies, which include not only those published but also those unpublished. When these studies are homogeneous in quality and their odds ratios homogeneous in quantity, the method can eliminate publication bias.

Bias↗
PubMed1991

Endometriosis of bladder after menopause.

We report a rare case of endometriosis of the bladder in a 68-year-old postmenopausal woman. The patient had not received any exogenous estrogen therapy and the hormone levels were normal for a castrated female subject. Endometriosis of the bladder should be considered as a cause of an abnormal mass of the bladder even after menopause. This case documents that urinary involvement by endometriosis may persist even after years of a hormonally castrated state.

Aged↗
PubMed1991

Programmable sweep radiometer system as a new tool for non-invasive thermometry.

A new microwave radiometer system consisting of a frequency sweep-type radiometer and an ultra wideband antenna has been developed. A computer-controlled radiometer system covers the input frequency range from 0.5 GHz to 8 GHz. It can be used not only as a multispectral radiometer system whose frequencies can be chosen freely, but also as a frequency sweep-type radiometer system whose frequency is continuously swept during measurement. When an antenna is attached to a forearm, the sensitivity of the radiometer system exceeds 0.09 degree C when the integration time is 3 sec and IF bandwidth is 500 MHz. The new microwave radiometer system may be utilized for non-invasive thermometry of the human body.

Humans↗
PubMed1991

Effects of retinoids on iodine metabolism, thyroid peroxidase gene expression, and deoxyribonucleic acid synthesis in porcine thyroid cells in culture.

Effects of retinoids on DNA synthesis, iodine metabolism, and thyroid peroxidase messenger RNA levels were studied in cultured porcine thyroid cells. Retinol (10(-8)-10(-5) M) alone did not affect DNA synthesis but potentiated that induced by epidermal growth factor or insulin-like growth factor-I without changes in the number or affinity of receptors for the growth factors, suggesting that retinol stimulates postreceptor events responsible for DNA synthesis. Retinol was an inhibitor of TSH-stimulated iodine metabolism. Iodide uptake and release of organified iodine stimulated by TSH or forskolin were inhibited dose dependently by treatment with retinol. The inhibition was detected at 10(-8) M and was approximately 50% at 10(-6) M. The potency of retinoic acid was comparable to that of retinol. The inhibitory effect of retinol was detected after treatments of thyroid cells for 24 h, and the maximal effect occurred after 48 h incubation. The cAMP accumulation in cultures treated with TSH plus retinol was lower than that of control cultures treated with TSH alone. However, iodide uptake stimulated by 8-bromo-cAMP was also inhibited by retinoids. Retinol reduced TSH- or 8-bromo-cAMP-stimulated gene expression of thyroid peroxidase. Thus, the data suggest that retinoids inhibit TSH-stimulated iodine metabolism by reducing cAMP accumulation and also by acting on the steps subsequent to cAMP production.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1991

[CT-guided biopsy of paraaortic lesions: report of three cases].

Computed tomographic (CT)-guided biopsies of the lesions in paraaortic region were performed for three urologic disease conditions: retroperitoneal fibrosis, lymph node metastases of transitional cell carcinoma of renal pelvis and lymph node metastasis of renal cell carcinoma. The biopsies were performed without complications using the Bard Biopty biopsy gun with a Bard Biopty-Cut needle. Every biopsy specimen we obtained by the Biopty rendered an excellent biopsy core from which a definite histopathological diagnosis was made. CT-guided biopsy is considered to be safe and useful for diagnosis of the disease of the paraaortic region, even when ultrasonography guided biopsy is difficult. The use of the Biopty for CT-guided biopsy provides a high quality specimen for histopathological diagnosis.

Aged↗
PubMed1991

[A case of idiopathic chronic scrotal hematocele].

A case of chronic scrotal hematocele is reported. A 63-year-old male first noticed the painless swelling of his left scrotal contents about 30 years before he visited our clinic on September 16, 1987. Examination revealed a hard mass, 10 x 8 cm in diameter, in the left scrotum. The scrotum did not transmit light. Since it was impossible to exclude testicular tumor completely, we performed left high orchiectomy. The extracted mass contained old brownish black clotted blood and a normal testis. Histopathological examination revealed that the hematocele showed a dense, fibrous wall with hyalinization. Six cases of chronic scrotal hematocele including our case have been reported in the Japanese literature.

Chronic Disease↗
PubMed1990

Induction of pituitary tumors in germ-free rats exposed to Aspergillus versicolor.

We clarified the role of mold exposure in pituitary tumor induction using 53 germ-free Wistar rats exposed before birth and continually exposed thereafter, to Aspergillus versicolor alone. Rats were autopsied at 540 to 730 days. Untreated germ-free controls were autopsied on day 730. Thirty-three of the 53 monoassociated rats had pituitary tumors (62.3%), while only three of the 41 control germ-free rats had tumors (7.3%). It seems likely that this high incidence of pituitary tumor in the experimental rats is due to metabolites derived from the mold.

Adenoma↗
PubMed1990

[Study on influence of cigarette smoking on the mutagenicity of urine. I. Influence of cigarette smoking on the mutagenicity of urine in healthy smokers and bladder cancer patients].

We studied the mutagenicity of urine of healthy smokers and smokers with bladder tumors by the Ames test. The 41 healthy smokers studied showed a significant increase in urinary mutagenic activity compared to the 24 passive smokers and the 22 non-smokers, but there was no significant difference between the passive smokers and non-smokers. In the 5 healthy subjects, the urinary mutagenic activity increased in accordance with the increase of tobacco consumption. In the 32 healthy subjects and 22 smokers with bladder tumors, the time-course changes of the mutagenicity of urine after smoking were investigated by testing the urine every 2 hours. In the healthy subjects, urinary mutagenic activity was increased up to 4 hours after cigarette smoking and decreased to the level noted before smoking after the 6th hour. By contrast, in the 22 smokers with bladder tumors, the urinary mutagenic activity remained high even after the 6th hour, and only decreased to the level seen before smoking after the 8th hour. The influence of smoking on the mutagenicity of urine tended to protract in smokers with bladder tumors in comparison to healthy smokers. There was no correlation between urinary mutagenic activity and tumor status and recurrence rate of the bladder tumors.

Adult↗