Biomedical subjects
Publications and source records attributed to A Masunaga.
We report herein an unusual case of a 35-year-old Japanese man who underwent thoracotomy for a mass in the mediastinum which was found to be a well circumscribed localized tumor within the thymus. Focal thymic hyperplasia in adults is extremely rare and the clinicopathological features of this case were particularly interesting and posed great difficulty in establishing a diagnosis.
Expression of the apoptosis-related antigens, Fas and BM-1, in thymuses from patients with myasthenia gravis (MG) was examined using immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Fas antigen was markedly decreased in lymphoid follicles in thymuses from patients with MG, but was expressed diffusely in the remaining thymus tissues and in neonatal thymuses. BM-1 antigen was not expressed in the lymphoid follicles or other parts of the thymus. Fas mRNA was also decreased to various degrees in the thymuses from MG patients. Therefore, Fas antigen may play an important role in autoimmune diseases including MG.
A 66-year-old woman was diagnosed as having myoma of the uterus and total hysterectomy with bilateral salpingo-oophorectomy was performed. The histopathological findings were puzzling, and the case was finally diagnosed as intramural uterine stromal tumor with epithelial differentiation. Three years after the operation, a firm tumor developed in the pelvic cavity. Laparotomy failed to remove the tumor and neither CAP (cyclophosphamide 500 mg, adriamycin 50 mg, CDDP 70 mg) therapy nor radiation therapy was effective. Oral administration of etoposide (25 mg/day), however, showed PR (50% decrease) as determined by CT scanning, and ultrasonography, and no metastatic lesions were found. This tumor was coincident with the endometrial stromal tumor with epithelial elements classified by Clement and Scully. The histological feature of the tumors and the efficacy of oral etoposide therapy are discussed in this study.
The reactivity of PC47H, a monoclonal antibody (mAb) directed against fucosylceramide, with cells of lymphoid lineage was examined. Immunoreactive fucosylceramide (FC) was recognized only in pokeweed mitogen (PWM)-stimulated B blasts, plasma cells and germinal center cells. mAb PC47H did not react with T cells at different stages or with peripheral blood B cells. Furthermore, FC was expressed abundantly in blastic cells of B-cell lymphoma, multiple lymphoma and myeloma cell lines KMS-12-BM and KMS-12-PE. In other words, FC was expressed more strongly in mature than in immature B cells. Immunoelectron microscopy showed that FC was located in the plasma membrane and rough endoplasmic reticulum. mAb PC47H can therefore be used as a unique B-cell differentiation marker for study of B-cell activation and differentiation and clonal analysis of lymphoid malignancies.
Relationships among tenascin expression, DNA ploidy, and P-glycoprotein were examined in 81 primary human colon cancers and 61 metastatic lymph nodes. First, the DNA ploidy patterns of colon cancerous tissue surrounded (TN+) and not surrounded (TN-) by tenascin immunoreactivity were investigated. Then the expression of P-glycoprotein, one of two multidrug resistance gene products, was examined in TN+ and TN- colon cancer tissues by immunohistochemistry. Aneuploid DNA patterns were observed at high frequency in TN- colon cancer tissues (37/61) and metastatic lymph nodes (44/52). In contrast, diploid DNA patterns were observed predominantly in TN+ colon cancer tissues (50/56). Although P-glycoprotein expression was observed in primary TN+ and TN- colon cancer (9/81), the level of P-glycoprotein expression was not correlated with DNA aneuploidy in TN- colon cancer tissues. Overall, reduced tenascin expression was correlated well with DNA aneuploidy, but no significant correlation was found between DNA aneuploidy and P-glycoprotein appearing when cancer cells become resistant to several anti-cancer drugs. Thus, tenascin may play an important role in preventing colon cancer cells from invading surrounding tissues.
L26 antigens (33- and 30-kDa proteins) are known to be present in human B lymphocytes. We have found that L26 antigens were strictly confined to the thymic medulla. However, the L26 antigens were not as abundant as those in human tonsils. At the ultrastructural level, L26 antigen-positive cells corresponded to thymic epithelial cells with thick bundle-like cytoplasmic filaments. These features may be useful for the identification of thymic epithelial cells both in vitro and in vivo.
The nm 23 gene product, which possesses nucleoside diphosphate kinase activity, is a possible mediator of cancer cell invasion and metastasis. It has been divided into two distinct gene products, nm23-H1 and nm23-H2. We have developed a method for detecting nm 23-H1 and nm 23-H2 RNA using the polymerase chain reaction, based on the amplification of complementary DNA copies of nm 23-H1 and nm 23-H2 RNA. Using this method, the nm 23-H1 and nm 23-H2 messenger (m)RNA levels in 35 thyroid papillary carcinomas, 11 metastatic lymph nodes from patients with thyroid papillary carcinomas, five thyroid follicular adenomas, and three normal thyroid tissue samples were studied. Both nm 23-H1 and nm 23-H2 mRNA were expressed ubiquitously in normal and malignant thyroid tissues. However, in metastatic lymph nodes no (3 of 11) or weak expression (8 of 11) of nm 23-H1 mRNA was observed, the extent of which was inversely proportional to the degree of cancer cell occupancy, whereas nm 23-H2 mRNA was expressed and the levels were similar to those in other tissue tested. These results show that nm 23-H1 only may play a role in cancer cell invasion and metastasis although the exact mechanisms involved have yet to be elucidated.
We have developed a sensitive reverse transcription (RT)-polymerase chain reaction (PCR) to evaluate multidrug resistance in various tissues, using seven mdr-specific primer sets. mdr1 mRNA expression was noted in 16/197 samples. However, the apparent degree of mdr1 mRNA expression depended on the sequence of the primers employed. These findings suggest that more than two sets of primers should be used for effective RT-PCR.
A case of intrauterine tumor in a 62-year-old Japanese woman is presented. It was thought initially that this was a case of uterine tumor resembling an ovarian sex cord tumor. To examine the cytological features of the tumor cells, electron microscopical and immunohistochemical studies were done, and a hormone assay of the tumor tissue was performed. The tumor cells were rich in rough endoplasmic reticulum (rER), mitochondria and microfilaments. Some tumor cells tended to form glandular patterns, but these epithelial elements were frequently scattered among fibrous stromal elements. Though many tumor cells with an epithelial appearance possessed a large quantity of cytokeratin and vimentin, they did not secrete estradiol, progesterone, testosterone or human chorionic gonadotropin. This case was finally diagnosed as an intramural uterine stromal tumor with epithelial differentiation after taking all the available data into consideration. This would be classified as an endometrial stromal tumor with epithelial elements, recently proposed and named by Clement and Scully.
We have studied expression of tenascin (TN) in colonic carcinoma cells from 81 patients with colonic carcinoma without (20) and with (61) lymphogenous metastases, in order to assess whether TN plays a role in local invasiveness and metastasis of tumors. In metastatic colonic carcinoma tissues from 52 cases, moderate, partial expression of TN was observed in the primary foci but no TN expression was observed in tissues from 9 others. However, in every case of nonmetastatic colonic carcinoma, very strong TN expression was observed in the tissues. Furthermore, the presence of dense TN accumulation correlated well with the prognoses (1-year survival) of colonic cancer patients (p less than 0.01). Weak TN expression was observed in 24/61 of the metastatic lymph nodes examined. In 2 patients with metastatic colonic carcinoma, the colonic cancer cells produced TN. TN may, therefore, play a role in limiting or preventing local tumor invasion rather than preventing metastasis and is a useful marker for predicting the prognoses of patients with colonic cancer.
We analyzed immunohistologically the expression of T-cell receptor (TCR)alpha chain on human tonsils and on T-cell lymphoma (T-ML) tissues using the avidin-biotin-peroxidase method. A murine monoclonal antibody alpha F1, specific for the constant region of the TCR alpha chain, was employed. On normal tonsil, alpha F1-positive cells were observed mainly in T-zones and germinal centers. In T-zones, the staining intensities varied markedly, with heavy staining evident in less than one fourth. In germinal centers, a proportion of stained cells showed a histiocytic pattern with small cytoplasmic projections. All the T-ML tissues expressed TCR alpha, whereas the staining intensities varied among cases and among lymphoma cells. No correlations were observed in the expressions of TCR alpha chain and other T-cell markers including CD3, CD4 and CD8.
The chronic toxicity study of mofezolac (N-22), a new developed analgesic and anti-inflammatory agent, was carried out in beagle dogs by oral administration of the test compound at dose levels of 1, 3, 6 and 12 mg/kg once daily for 52 weeks. The recovery study was also carried out by withdrawal for 5 weeks. 1. No death occurred during the administration and recovery periods in all groups, there were no abnormal findings due to N-22 administration on behavior and appearance, body weight and food consumption. 2. There were no abnormal findings due to N-22 administration on fecal test, urinalyses, hematological and biochemical examinations, hepatic and renal function tests, ophthalmological examination, electrocardiography, blood pressure and organ weight. 3. By histopathological examination, loss of villi in small intestine was found in one female of 6 mg/kg group, erosion in small intestine in one male of 12 mg/kg group, and shortening of villi and ulcer in small intestine in each one female of 12 mg/kg 4. Accordingly, the non-effective dose levels of N-22 were estimated to be 6 mg/kg for male and 3 mg/kg for female in this study.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.