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Biomedical subjects

S Takai

Publications and source records attributed to S Takai.

At least 289 records · Page 16Linked to original sources
PubMed1990

[Tumor suppressor gene: implication in the clinical medicine].

Several genetic events are necessary for a cell to become malignant. Some of these events are activation of proto-oncogenes, and other events are loss of normal function of tumor suppressor gene(s). Two or more different tumor suppressor genes may be inactivated in some tumors, and the same suppressor gene may be involved in different types of tumors. Loss of constitutional heterozygosity (LOH) in the tumor suggests that a certain tumor suppressor gene may reside near the locus of the probe by which the LOH was demonstrated. However, LOH is not necessarily found when a tumor suppressor gene is inactivated. The frequency of LOH found by a probe depends upon the distance between the probe and the tumor suppressor gene. Moreover, inactivation of the suppressor gene by point mutation or very small deletion does not cause any change in electrophoretic mobility of the DNA fragment detected by the probe. Treatment of a cancer by tumor suppressor gene(s) is not possible until a technique by which we can introduce the gene into all the tumor cells is established. At present, clinicians should cooperate with basic scientists in the search for tumor suppressor genes. The comparison of clinical features and the genetic alterations in the tumor will shed light on the malignant behavior of the tumor cells such as rapid growth and/or tendency to metastasis.

Adenomatous Polyposis Coli↗
PubMed1990

[Sipple's syndrome: a case report].

A 41-year-old woman was hospitalized for evaluation of diabetes mellitus and hypertension. The hormonal and radiological examinations revealed that she had pheochromocytoma of bilateral adrenal gland and medullary carcinoma of thyroid gland. Therefore, she was diagnosed as having Sipple's syndrome. She had no definite familial history, but her two sisters, already dead, had been strongly suspected of having had pheochromocytoma. First, bilateral adrenalectomy was performed and secondly, total thyroidectomy, excision of parathyroid and cervical lymph node dissection were performed. Histopathological diagnosis was pheochromocytoma of bilateral adrenal gland, medullary carcinoma of thyroid gland and chief cell hyperplasia of parathyroid gland. We report a case of Sipple's syndrome, which probably is the 88th case in Japan, with the review of the previous Japanese literature.

Adrenal Gland Neoplasms↗
PubMed1990

[Smoothed skeletal maturity curve of Japanese children by Tanner-Whitehouse 2 (TW2) method and its application].

This paper reports the TW2 skeletal maturity status on some 8,800 Ogi schoolchildren aged 6.5-17.5 years, who participated in the 1979-1988 Ogi Longitudinal Growth Study. The smoothing B-spline function was applied to 3, 10, 25, 50, 75, 90, and 97 percentile TW2 RUS, carpal and 20-bone scores. The carpal maturity pattern was variable throughout the periods. The RUS matured with narrower variation during preadolescent period, then became variable with advancing age. The dispersion of the 20-bone score converged toward post-adolescent period. Ogi children showed retarded skeletal maturation compared with British standard during preadolescent period, then the children have surpassed the standard at adolescence. The skeletal maturity status of Ogi children was not identical with that of two Chinese samples. Harbin and Beijing children. Ogi girls showed similar maturity pattern to Harbin girls, but Ogi boys retarded in the RUS score compared with Harbin boys during preadolescent period. Ogi girls retarded in the TW2 20-bone bone age at ages 7-9 years, then they surpassed Beijing girls. Ogi boys always exceeded Beijing boys during the period of 7-17 years. Tokyo children in 1960s surpassed the Ogi children during whole periods studied. Tokyo children in 1980s exceeded Ogi children only at postadolescent period in boys, and they retarded during adolescent period in girls. I examined a possible secular change in the skeletal maturation with a cohort analysis of Ogi children. The median test revealed the secular change only at the specific cohorts and age classes, but not general secular trend of acceleration of the skeletal maturation. I examined the socioeconomic influence to the skeletal maturation within Kyushu populations, Naze, Nomozaki and Ogi children. Although Ogi and Naze samples showed similar socioeconomic status, their skeletal maturity status differed significantly. Ogi and Nomozaki children showed similar skeletal maturity pattern irrespective of their socioeconomic discrepancy.

Adolescent↗
PubMed1990

[A case of primary pulmonary hypertension with high venous thromboxane B2 concentration].

A 30-year-old male was admitted because of dyspnea, which had started three years before the admission. Chest roentgenogram showed prominence of the proximal pulmonary arteries and diminished vascularity of the peripheral pulmonary arteries. Electrocardiogram showed right axis deviation and right ventricular hypertrophy. Right heart catheterization revealed a markedly elevated pulmonary arterial pressure and pulmonary vascular resistance with normal capillary wedge pressure. Oximetry showed no evidence of intracardiac shunt. Perfusion lung scan revealed nonsegmental, patchy defects in both lungs. Pulmonary arteriography showed no evidence of pulmonary thromboembolism. From the above findings, primary pulmonary hypertension was diagnosed. Nifedipine, ISDN, prazosin, and captopril were administered to evaluate the short term-effect of he vasodilators. Nifedipine was found to be the most effective. The venous thromboxane B2 level was high. After oxygen therapy, venous thromboxane B2 level fell within the normal range following improvement of arterial oxygenation and decrease in venous FDP level. Hemodynamic changes induced by ice-water hand immersion showed marked increase in the mean pulmonary arterial pressure and total pulmonary arterial resistance. These results suggested that chemical mediators such as thromboxane, and pulmonary arterial vasospasm were involved in the pathogenesis.

Adult↗
PubMed1989

[Graves' disease with markedly elevated serum immunoglobulin E].

A 37-year-old female with Graves' disease was reported. An abnormally high concentration of serum IgE was observed by radioimmuno-sorbent test before treatment. Laboratory findings showed no evidence of atopic diseases or other known diseases with hyperglobulinemia E. There is no reported case of Graves' disease associated with remarkably elevated plasma IgE level. In the present patient, a further elevation of serum IgE concentration was observed when the dose of methimazole reached about 500 mg in total. Allergic mechanism may be the cause of this phenomenon. Serum IgE level was decreased gradually after replacement of methimazole by propylthiouracil. IgE level was not parallel with thyroid functions, and even when her thyroid function was normalized after subtotal thyroidectomy, IgE concentration was still increased around 900 IU/ml. The mechanism of hyperglobulinemia E in this case was discussed.

Adult↗
PubMed1989

An improved method for the detection of IgE antibody of defined specificity by ELISA using rat monoclonal anti-IgE antibody.

An improved method for the detection of IgE antibody of defined specificity by ELISA using rat monoclonal anti-IgE antibodies is described. The innovation consists of coating the plates first by a monoclonal rat anti-murine IgE antibody, adding the sera to this antibody-coated plates and then adding the biotin-conjugated antigen after the sera. The plates are then reacted with streptavidin-peroxidase and developed. This procedure eliminates possible competitions with other isotypes of the same specificity. The method is useful especially to quantitate IgE with defined specificity in the presence of high amounts of isotypes of the same specificity.

Animals↗
PubMed1989

Squamous metaplasia with Hashimoto's thyroiditis presenting as a thyroid nodule.

A 59-year-old Japanese female presented a well-limited and movable thyroid nodule. Histologically, the nodule consisted of clusters of squamous cells surrounded by dense connective tissue in Hashimoto's thyroiditis. The squamous cells were well arranged and showed no mitotic figures. We therefore interpreted this nodule as being squamous metaplasia with Hashimoto's thyroiditis rather than squamous carcinoma of the thyroid. There are no previous reports in the literature of nodular formation of squamous metaplasia in the thyroid.

Carcinoma, Squamous Cell↗
PubMed1989

Close linkage of MEN2A with RBP3 locus in Japanese kindreds.

The gene responsible for multiple endocrine neoplasia type 2A (MEN2A) has recently been assigned to the pericentromeric region of chromosome 10 in European Caucasian kindreds by linkage analysis using a DNA marker, interstitial retinol-binding protein 3 (RBP3). We have found tight linkage between the MEN2A and RBP3 loci in Japanese MEN2A kindreds. The maximum lod score is 5.19 at a recombination fraction of 0.00. This result suggests that mutation of a certain gene close to RBP3 is responsible for MEN2A irrespective of ethnic backgrounds.

Female↗
PubMed1989

Allele loss on chromosome 10 and point mutation of ras oncogenes are infrequent in tumors of MEN 2A.

The multiple endocrine neoplasia type 2A (MEN 2A) gene has been mapped to the centromeric region of chromosome 10 by linkage analysis. We examined 36 medullary thyroid carcinomas (MTCs) (16 hereditary and 20 sporadic) and ten pheochromocytomas (eight hereditary and two sporadic) to detect loss of alleles on chromosome 10 using seven polymorphic DNA markers mapped to this chromosome. Of 20 informative cases, only one (5%) sporadic MTC showed loss of heterozygosity at the locus RBP3. Allele loss at the RBP3 locus was not found in pheochromocytomas from six heterozygotes. All tumors retained constitutional heterozygosity at six other loci on chromosome 10 (D10S17, D10S34, D10S24 on the short arm, D10S15 in the pericentromeric region, D10S20, and D10S4 on the long arm). Our findings suggest that the second hit for tumorigenesis in MEN 2A may not be loss of function of the normal allele at the homologous locus on the other copy of chromosome 10. Mutated ras oncogene was found only in one of 18 MTCs at the codon 61 of H-ras.

Adrenal Gland Neoplasms↗
PubMed1989

Results of a screening program for multiple endocrine neoplasia type 2A: a clinical study of a Japanese family.

A Japanese family of 87 members in five generations with multiple endocrine neoplasia type 2A (MEN 2A) is described regarding the utility of screening tests for early detection of medullary thyroid carcinoma and the potential for DNA diagnosis of MEN 2A gene carriers. The screening programs for family members in this series include measurements of plasma calcitonin concentrations after intravenous injection of pentagastrin (0.5 micrograms/kg/5 sec) and 24-hour urinary excretion of catecholamines. While 18 MEN 2A patients had been previously diagnosed, these screening programs revealed five additional patients with MEN 2A (aged 16, 19, 35, 37, and 57). Prediction of MEN 2A gene carriers by DNA analysis has been attempted but is not yet possible in this family.

Adolescent↗
PubMed1989

Protein kinase C activation in a 3T3 cell variant morphologically unresponsive to tumor-promoting phorbol esters.

To investigate the mechanism of the morphological changes induced in cells by tumor-promoting phorbol esters, we isolated a 3T3 cell variant which was morphologically unresponsive to phorbol esters and analyzed the activation of protein kinase C induced by the phorbol esters in it. The variant resembled the parent cells in its activation and appeared to have been altered at some step distal to the early events of protein kinase C activation.

Animals↗
PubMed1989

[The effect of thyroid hormone on the growth of thyroid cancer].

Thyroid cancer is well known to be hormone sensitive as well as breast cancer, prostatic cancer, and endometrial cancer of the uterus. Various experimental results suggest that the growth regulation for thyroid cancer, as well as the normal thyroid gland, appears to depend upon the TSH (Thyroid stimulating hormone) receptor on cell membranes. Differentiated thyroid carcinoma cells possess TSH receptor, although anaplastic carcinoma cells do not; therefore suppression therapy of TSH with thyroid hormone is considered to be effective against differentiated thyroid carcinoma. It has been recognized that some recurrent differentiated thyroid cancers cause regression in size in response to treatment with thyroid hormone. But the administration of the thyroid hormone after the operation for the differentiated thyroid carcinoma does not necessarily enhance the survival rate. To analyze the difference in survival rate is very difficult because of the excellent survival rate of thyroid cancer patients after the operation. It is hoped that further clinical study and laboratory investigation about suppression in adjuvant therapy for differentiated thyroid cancer will give us a conclusive answer.

Adolescent↗