Search PubMed⌕ Search

Biomedical subjects

T Kameya

Publications and source records attributed to T Kameya.

At least 145 records · Page 8Linked to original sources
PubMed1990

Relationships among expression, transcription and rearrangement of T-cell receptor beta gene in T-cell lymphomas.

The expression of T-cell receptors (TCR) in malignant lymphomas was examined immunohistochemically by monoclonal antibodies which react with the TCR beta or TCR delta chain. TCR beta was expressed in 16 out of 47 non-Hodgkin's lymphomas. These included 15 T-cell lymphomas and 1 Ki-1 lymphoma. The anti-TCR beta chain antibody, beta F1, did not react with 26 B-cell lymphomas, 1 Ki-1 lymphoma or 6 Hodgkin's disease. This anti-TCR delta chain antibody, TCR delta 1, did not react with any type of malignant lymphoma. Although TCR beta and CD3 were co-expressed in normal lymphoid tissues and most T-cell lymphomas, 3 cases of CD3+ CD4+ CD8- T-cell lymphoma failed to express TCR beta. TCR beta and Ig JH gene configurations in malignant lymphomas were examined by Southern hybridization. Although each of 9 T-cell lymphomas had a rearranged TCR beta locus, TCR beta gene rearrangement in the 3 cases of beta F1- CD3+ T-cell lymphomas was demonstrated by Southern blot. No transcripts of the TCR beta gene could be found in 2 out of the 3 beta F1- CD3+ T-cell lymphomas by Northern blot, indicating the lack of TCR beta protein expression to be due to non-transcription of the TCR gene. Loss of TCR beta proteins in these T-cell lymphomas is thus quite likely to be associated with T-cell tumour activation and progression, since 3 beta F1- CD3+ T-cell lymphomas expressed CD25 (interleukin-2 receptor) to a high degree.

Adolescent↗
PubMed1990

Somatostatin analogue (SMS 201-995) decreases plasma levels of corticotropin (ACTH) and corticotropin-releasing hormone in a patient with ectopic ACTH-producing tumors.

Effects of long-acting somatostain analogue (SMS 201-995) on plasma corticotropin (ACTH) and corticotropin-releasing hormone (CRH) levels were studied in a patient (63-year-old woman) with ectopic ACTH-producing tumors associated with type I multiple endocrine neoplasia (MEN-I). The patient had undergone bilateral adrenalectomy. Plasma CRH, as well as plasma ACTH, beta-endorphin and alpha-MSH, increased. The hormone levels were dramatically decreased by acute administration of SMS 201-995. Moderately higher doses of dexamethasone (0.05 or 0.1 mg/kg a day) did not decrease plasma CRH or ACTH. An extremely high dose of dexamethasone (0.2 mg/kg a day), however, decreased plasma ACTH, but failed to decrease plasma CRH. Acute administration of SMS 201-995 further lowered the level of plasma ACTH even in this condition. In addition to the decrease in ACTH, SMS 201-995 decreased plasma CRH. Chronic administration of SMS 201-995 continuously decreased plasma CRH, ACTH and beta-endorphin. The decrease in these hormone concentrations accompanied the disappearance of hyperpigmentation. These results suggested that SMS 201-995 inhibits hypersecretion not only of ACTH but also of CRH, and that the agent is therapeutically useful in normalizing the hypersecretion of these hormones.

ACTH Syndrome, Ectopic↗
PubMed1989

[Characterization and calcitonin secretion of a human well differentiated C-cell tumor cell line].

Useful cell lines actively producing hormone (s) have been rare, especially those of human origin. A C-cell tumor human cell line abundantly producing calcitonin and related hormones, TT-cell, has proved remarkably useful for the study of endocrine tumors as their representative model. We proved intracellular presence of translation and transcript products of calcitonin and calcitonin gene related peptide gene by immunostain, radioimmunoassay, immunoelectron microscopy, Northern blot and in situ hybridization. We also demonstrated remarkably enhanced secretion of the hormones and chromogranins by the stimulation of protein kinase activators such as phorbol ester, forskolin, and calcium-ionophore.

Animals↗
PubMed1988

Developmentally regulated expression of the calcitonin gene related peptide (CGRP) in rat lung endocrine cells.

Calcitonin (CT) and the calcitonin gene-related peptide (CGRP) are generated by alternative RNA processing from a single CT/CGRP gene. Recently, we reported the existence of CGRP-immunoreactivity and CGRP mRNA in endocrine cells or Kulchitsky (K) cells of human and rat lung [Wada et al. 1987b]. In this report, an examination was made of developmental changes in the expression of the CGRP gene in rat lungs by immunohistochemistry, radioimmunoassay (RIA) and Northern hybridization. CGRP-positive K-cells in lung tissue appeared on the 18th day of gestation. Their number was greatest on the 20th day of gestation and then decreased postnatally. The level of CGRP in rat lung was found to be highest in a 1-day-old neonate by RIA. In the Northern hybridization of rat lung using the CGRP 3' non-coding region (exon 6) of the first human CT/CGRP gene as the probe, 1.0 kilobase (kb) CGRP mRNA was found to be abundant on the 20th day of gestation and in a 1 day-old neonate. It thus appears that CGRP in rat lung is essential for pulmonary adaptation at birth and/or from the last intrauterine stage to the early neonatal period.

Animals↗
PubMed1988

Malignant pituitary tumors.

Pituitary malignancies are rare. The definition of pituitary malignancy is still subject to debate. Three types of malignancy with the description of clinical course and complete autopsy were presented; i) true carcinosarcoma, ii) ectopic sphenoid invasive tumor, and iii) post-irradiation sarcoma. The first true carcinosarcoma had a long natural tumor history of 46 years, ending in malignant transformation with extracranial metastasis from a pituitary adenoma. The second ectopic sphenoid tumor was prolactin-producing, locally invasive, with the intact pituitary gland. The third post-irradiation sarcoma was followed by chromophobe pituitary adenoma. The interval between irradiation to the adenoma and malignant transformation to fibrosarcoma was about 14 years.

Adenoma↗
PubMed1988

Monoclonal antibody directed against neuroendocrine properties of both normal and malignant cells.

A monoclonal antibody, 6H7, was produced by the immunization of small cell carcinoma of the lung (SCCL). Immunohistochemical examination indicated that 6H7 reacted not only with SCCL but also various neuronal and/or endocrine tumors such as neuroblastoma, pheochromocytoma, carcinoid and adrenal cortical tumors. 6H7 was also reactive with normal neuroendocrine tissues including brain, spinal cord, thyroid follicular cells, pancreatic islet cells and adrenal cells. 6H7 did not react with squamous cell carcinomas, one large cell carcinoma or most adenocarcinomas of the lung, or carcinomas of the stomach, colon, pancreas, breast and esophagus. The antigen recognized by 6H7 was analyzed on gel filtration after purification of the antigen by liquid chromatography which indicated the molecular weight of the antigen to be 270,000-300,000. From SDS-PAGE analysis the antigen reactive with 6H7 appeared to consist of polypeptide dimers of 128,000.

Animals↗
PubMed1988

[Folliculo-stellate cells in normal human adenohypophyses and in pituitary adenomas].

Nine normal human adenohypophyses and 155 cases of pituitary adenoma of various endocrinological types were studied for existence of folliculo-stellate cells (FSCs) by an immunohistochemical method using the antibody for S-100 (S-100 protein). In all normal materials, S-100 positive FSCs were distributed throughout the glands, constituting 0.9-4.0% of the adenohypophysial cells. FSCs were morphologically characteristic showing a few slender cytoplasmic processes which extended among the other endocrine cells. On the other hand, FSCs were recognized in 13 cases (8%) of the adenomas, which we called FSC-containing pituitary adenomas. In them, S-100 positive FSCs existed diffusely in the tissue and increased in number, but did not differ in appearance from those in the normal gland. We also examined immunoreactivity of FSCs for the anti-GFAP (glial fibrillary acidic protein) antibody. GFAP positive cells showed a greater number than S-100 positive cells in the normal glands, but a smaller number in the adenomas. Ultrastructural features of FSCs were observed in the tumor by an electron microscope. We studied clinical aspects of these FSC-containing adenomas, expecting some common features. However, we found no rules in age, sex, endocrinological type, tumor size, previous therapy, intraoperative finding of the tumor, and recurrence. So far, the function of FSC has not been clearly elucidated, and the present study did not contribute in this respect. The property of FSCs which proliferate in some adenomas is enigmatic. They may be entrapped normal cells, or reactive hyperplastic cells, or neoplastic cells. We considered them reactive hyperplastic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1987

Activation of N-ras gene in a rat hepatocellular carcinoma induced by dibutylnitrosamine and butylated hydroxytoluene.

DNA samples from eighteen rat hepatocellular carcinomas, including those induced by oral administration of dibutylnitrosamine (DBN) with butylated hydroxytoluene (BHT), or DBN with butylated hydroxyanisole (BHA), have been tested for the presence of transforming activity by transfection assay with NIH3T3 cells. Of the eighteen samples, only one from a tumor induced by DBN and BHT gave transformants. the activated oncogene was identified as rat N-ras by Southern blot analysis.

Animals↗
PubMed1986

Histiocytes in nasopharyngeal carcinoma in relation to prognosis.

Forty-nine biopsy specimens of nasopharyngeal carcinoma and 20 biopsy specimens of nasopharyngeal mucosa obtained from non-cancer patients were studied for the presence of T-zone histiocytes (Langerhans' cells and their precursors) and macrophages by immunohistochemical methods with the use of antibodies against S-100 protein and lysozyme (lys), respectively. Patients with dense infiltration of T-zone histiocytes in the primary sites survived longer than those without such infiltration (mean survival times, 8, 39, and 72 months in the patients with the density of -, +, and ++, respectively; P less than 0.005). In contrast, there was no relationship between patient prognosis and density of lys+ macrophages in the tumor tissue (P = 0.33). The distribution of T-zone histiocytes in the tumor tissue was different from that of macrophages. T-zone histiocytes may play an important role in the immune reaction against cancer, probably acting through mechanism different from that of macrophages.

Adolescent↗
PubMed1986

Immunohistochemical examination of lung cancers using monoclonal antibodies reacting with sialosylated Lewisx and sialosylated Lewisa.

In order to explore the relationship between the expression of cancer-associated glycolipids such as sialylated Lex (SLEX) and sialylated Lea (SLEA) and the histological subtypes of lung cancers, 30 cases of small cell carcinoma (SCC) and 47 cases of non-small cell carcinoma (non-SCC) were examined immunohistochemically using monoclonal antibodies reacting with SLEX and SLEA. The forty-seven cases of non-SCC included 20 cases of adenocarcinoma, 20 of squamous cell carcinoma and 7 of large cell carcinoma. Tumour cells of most non-SCCs expressed SLEX and SLEA. In adenocarcinomas, the number of tumour cells having SLEX and SLEA was more than that of squamous cell carcinomas, large cell carcinomas and SCC. In SCC, 14 of the 30 cases were found to be positive for both antigens. Although the cancer cells of 11 cases of 17 intermediate cell type SCC had both antigens, the cells of only 3 of 13 oat cell tumours expressed SLEX and SLEA. The present study shows that SLEX and SLEA are useful markers for lung adenocarcinomas, that most cases of intermediate cell type of SCCs have characteristics similar to non-SCC but that many oat cell tumours lack them.

Adenocarcinoma↗
PubMed1986

Calcitonin-producing insulinoma. An immunohistochemical and electron microscopic study.

A pancreatic endocrine tumor measuring 1.5 X 1.0 X 1.0 cm in a 67-year-old man with recurrent hypoglycemic attacks was examined by immunohistochemistry and electron microscopy. The tumor cells were relatively uniform, and almost all of them were immunoreactive to insulin. A few calcitonin-positive cells could be identified scattering in tumor cell strands, and the content of calcitonin in the tumor was 85 ng/g wet tissue. Coexistence of insulin and calcitonin in tumor cells was demonstrated by using adjacent semithin sections of the Epon-embedded material. Electron microscopically, the tumor consisted of a single type of cells with secretory granules identical to B-cell granules in the normal counterpart.

Adenoma, Islet Cell↗
PubMed1986

Primary leptomeningeal ependymoblastoma. Case report.

Ependymoblastoma is considered to be a primitive malignant glioma with ependymal differentiation. This rare tumor occurs in very early life and shows rapid growth and a diffuse infiltration through the leptomeningeal space. The tumor cells are highly immature, with numerous mitoses and multilayered ependymal rosettes. The ependymoblastoma described in this report was found in a 17-year-old girl. In spite of detailed clinical and postmortem examinations, no definite primary site was identified in the neuraxis. The lesion spread predominantly throughout the leptomeningeal space. Histological analysis strongly suggested that this tumor originated from a heterotopic glial nest in the subarachnoid space. The absence of immunohistochemical neural tissue markers, glial fibrillary acidic protein, S-100 protein, neuron-specific enolase, and neurofilaments ruled out neuronal or glial differentiation. The authors were unable to find any previous report of primary leptomeningeal ependymoblastoma.

Adolescent↗