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Biomedical subjects

T Michigishi

Publications and source records attributed to T Michigishi.

153 records · Page 9Linked to original sources

Flow cytometric DNA measurement in benign and malignant human thyroid tissues.

The occurrence of aneuploidy in 108 normal, benign and malignant thyroid tissues was evaluated by DNA flow cytometry. Aneuploid cell populations were found in 60% of the papillary carcinomas, 67% of the follicular carcinomas, 52% of the follicular adenomas and in 10% of the multinodular goiters. None of the non-neoplastic thyroid lesions (chronic thyroiditis and Graves' disease) showed aneuploidy. No significant differences in frequency of aneuploidy and DNA index were found between the well-differentiated and trabecular types of the papillary carcinomas (53%; 1.29 +/- 0.10 vs 75%; 1.30 +/- 0.10, respectively), although the latter type of papillary carcinomas have been shown to be associated with a more aggressive clinical behavior. Also no differences in frequency of aneuploidy were noted between the follicular carcinomas and the follicular adenomas, but the DNA index was significantly higher in the former. These findings indicate that flow cytometric analysis of DNA content may not be helpful in the evaluation of the clinical behavior of papillary carcinomas or in the determination of malignancy of follicular tumors, but may be useful in differentiating neoplastic from non-neoplastic thyroid lesions.

Adenocarcinoma↗

Differential (Ha-, K- and N-) ras p21 expression in benign and malignant human thyroid tumors: an immunohistochemical study.

An immunohistochemical study of 24 thyroid carcinomas, 10 thyroid adenomas and 10 normal thyroids was performed using monoclonal antibodies directed against each of the three members of ras p21s; Ha-, K- and N-ras p21. Normal thyroids showed a negative staining for all of the three ras p21s. The expressional levels of the three ras p21s were various in each benign and malignant thyroid tumor, but a higher expression of Ha- and N-ras p21 and a lower or negative expression of K-ras p21 was a common finding in thyroid tumors of all histologic categories. There were no correlations between the expressional levels of ras p21s and the histologic subtypes, tumor size or lymph node status in the thyroid carcinomas.

Adenocarcinoma, Follicular↗

Immunohistochemical demonstration of thyroid peroxidase (TPO) in human thyroid tissues from various thyroid diseases.

Human thyroid peroxidase (hTPO) was detected immunohistochemically in 61 normal, benign and malignant thyroid tissues with a monoclonal antibody (38E) against hTPO using paraffin-embedded sections. Thyroid peroxidase was expressed intensely not only in tissues from Graves disease and hyperfunctioning adenomas, but also in those from carcinomas, adenomas and Hashimoto's thyroiditis. The staining pattern of TPO in the follicular cells was a diffuse and fine granular one in the normal thyroids, Graves' thyroids and adenomas, but abnormal coarse granular deposits of TPO were characteristically identified in most of the papillary carcinomas and Hashimoto's thyroiditis. These coarse granular deposits of TPO suggested that qualitative or structural changes in the TPO molecule are present in carcinomas and Hashimoto's thyroiditis. Consequently, these qualitative changes in TPO may be responsible for the lack of biochemically measured TPO activity in these diseases. This finding may also be useful in distinguishing between benign and malignant thyroid tumors.

Humans↗

Tumor proliferation-related markers in papillary thyroid carcinomas: correlation with histologic subtypes.

Four sorts of tumor proliferation-related markers were studied in 50 papillary carcinomas of the thyroid, and the results were correlated with the histologic subtypes of papillary thyroid carcinoma, which have been shown to be associated with the prognosis of the disease. The mitotic count analyzed by light microscopy, the proliferating cell nuclear antigen (PCNA) and the epidermal growth factor (EGF) expressions by immunohistochemical analysis, and the ploidy status analyzed by DNA flow cytometry were used as the proliferation-related markers in this study. The presence of mitoses, high PCNA score and DNA aneuploidy did not correlate with the histologic subtypes, patient age, sex or the tumor extent. Only EGF expression was significantly correlated with the histologic subtypes. This finding suggests that EGF expression may be the most reliable marker to predict the prognosis of papillary carcinoma of the thyroid.

Adult↗

The diagnosis of internal mammary node metastases of breast cancer.

It is important to know the status of internal mammary lymph node (IMN) in estimating the prognosis in patients with breast cancer and/or planning the treatment. In the first series of this study, the diagnostic value of internal mammary lymphoscintigraphy (IMLS) and that of parasternal sonography (PS) were evaluated in 57 patients. The overall diagnostic accuracy of IMLS was 72% and that of PS, 84%, compared with IMN metastases confirmed on a biopsy. In the second series, 23 patients who underwent extended radical mastectomy and were found to have IMN metastases, were examined for the sizes and locations of metastatic IMN. Minute metastatic lymph nodes not detectable by IMLS or PS were found in 9 (39%) of the patients. However, the incidence of metastases to the first and/or second intercostal spaces was 97% for the patients. We concluded that a biopsy of the first and second intercostal spaces is useful in providing the information of IMN status.

Adult↗

Multivariate study of prognostic factors for differentiated thyroid carcinoma: the significance of histologic subtype.

We re-examined 239 patients with differentiated thyroid carcinoma (222 with papillary carcinoma and 17 with follicular carcinoma) especially for the clinico-pathologic entity of poorly differentiated carcinoma, and made univariate and multivariate analyses of the results to evaluate whether it would be of value in estimating the prognosis in thyroid cancer patients. In the univariate study, no significant difference was found in either survival and disease-free survival between papillary and follicular carcinomas, but between well differentiated and poorly differentiated carcinomas. In the multivariate study, however, the presence of poorly differentiated carcinoma did not appear to be an unfavorable prognostic factor. The sex, tumor size, and presence of distant metastases or grossly malignant residue in the neck after operation were, on the other hand, confirmed by the analyses to be important prognostic factors. We concluded that histologic subclassification may be less useful in estimating the prognosis in patients with differentiated thyroid carcinoma than other factors such as sex and the extent of the tumor.

Adenocarcinoma↗

N-myc protein expression in human breast carcinoma: prognostic implications.

The overexpression of N-myc gene and its protein products has been thought to be limited to cases of neuroblastoma, retinoblastoma and small cell lung carcinoma, but there is increasing evidence of its wider distribution in human tumors. This study showed that the protein of N-myc gene is associated in normal, benign and malignant human breast tissues. We found that N-myc oncoprotein is overexpressed in most breast carcinomas and that N-myc overexpression is significantly correlated with clinical stage, and histological grading of the tumors, and, more importantly with the clinical outcome of the patients. Analysis of DNA, mRNA and protein levels suggested that the high N-myc expression in breast cancer occurs without concomitant gene amplification. The finding of a direct inverse correlation between N-myc overexpression and the prognosis of patients with breast carcinoma suggests that N-myc expression may be useful as a prognostic factor in human breast cancer.

Breast Neoplasms↗

Breast conserving treatment versus modified radical mastectomy in Japanese patients with operable breast cancer.

From January, 1988 to October, 1995, 96 patients with operable breast cancer were treated by breast conserving treatment (BCT) including wide excision and axillary dissection followed by breast radiation. During the same period, 188 patients were treated by modified radical mastectomy (MRM) with or without breast reconstruction. In order to compare the survival of BCT and MRM groups, univariate and multivariate analyses were performed in this retrospective study. Univariate analysis revealed that the 5-year survival rates in the BCT and MRM groups were 97% +/- 2% and 87% +/- 3%, respectively (p < 0.05 with the Cox-Mantel test). However, the baseline variables were different between the groups. The adjusted Cox regression analysis revealed that the results of BCT were almost equivalent with those of MRM. Moreover, no breast recurrence was found in the BCT group. Therefore, it is suggested that our technique of BCT is as effective as modified radical mastectomy in treating operable breast cancer in Japanese patients.

Adult↗