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Biomedical subjects

P Soares

Publications and source records attributed to P Soares.

36 records · Page 2Linked to original sources
PubMed1997

Prognostic factors in thyroid carcinomas.

The AA review the so-called prognostic factors in thyroid carcinoma taking in consideration four of the five major histotypes of thyroid tumours: Papillary ca. (5-year-survival -91%), follicular ca. (73%), poorly differentiated ca. (48%) and undifferentiated ca. (0%), with an emphasis on papillary carcinoma. The prognostic factors are described in two major groups: Clinicopathologic factors comprising the classic clinicopathologic features--age, gender, size, extrathyroidal extension, vascular invasion, nodal metastization and distant metastization--and Biologic factors, comprising a group of heterogeneous and less classic features such as DNA content and proliferation markers, oncogenes and tumour-suppressor genes, growth factors and growth factor receptors, pro- and anti-apoptotic genes, mucin and histo-blood group antigens, cytoskeletal filaments, adhesion molecules, and so forth. Finally, the AA address briefly a third group of (prognostic) factors that reflect the interaction between the neoplastic cells and their microenvironment: extracellular matrix and proteolytic enzymes (laminin, collagen IV, fibronectin, collagenases, alpha-1 anti-trypsin) and lymphocytic infiltration (S-100 positive cells, IGF-I and IGF-I receptor).

Adenocarcinoma, Follicular↗
PubMed1995

Recent advances in cytometry, cytogenetics and molecular genetics of thyroid tumours and tumour-like lesions.

In this review we summarize the most recent advances of flow and image cytometry, cytogenetics and molecular genetics of tumours and tumour-like lesions of the thyroid, especially focusing on the putative relationship between nodular goitres and adenomas, the differential diagnosis of benign and malignant neoplasms and the pathogenesis and prognosis of carcinomas. Data obtained by in situ hybridization and immunohistochemical detection of proliferative markers, metal binding proteins and oncogenes, anti-oncogenes, growth factors and growth factor receptors are also used whenever appropriate.

Cytogenetics↗
PubMed1994

Immunohistochemical detection of p53 in differentiated, poorly differentiated and undifferentiated carcinomas of the thyroid.

In an attempt to find whether or not p53 immunoreactivity in the thyroid gland is restricted to undifferentiated carcinomas and to evaluate the putative prognostic usefulness of its detection, we investigated p53 immunoreactivity in a series of 14 benign thyroid lesions and 65 thyroid carcinomas (12 papillary; six minimally invasive follicular; four widely invasive follicular; 31 poorly differentiated and 12 undifferentiated tumours). Unequivocal nuclear immunostaining for p53 was observed in two widely invasive follicular carcinoma (20.0%), five poorly differentiated carcinomas (16.1%) and in 10 undifferentiated carcinomas (83.3%). The percentage of immunoreactive cells was much smaller in the former groups than in undifferentiated carcinomas. Despite a trend to a more aggressive behaviour of the p53 immunoreactive cases no significant differences in the outcome of patients with positive and negative tumours was found when the comparison was made within each category of carcinomas. We conclude that p53 immunoreactivity can be detected both in undifferentiated carcinomas and in some differentiated and poorly differentiated thyroid carcinomas. Larger series of cases are necessary to evaluate the prognostic usefulness of this finding.

Adenocarcinoma, Follicular↗
PubMed1993

Cytogenetic findings in eleven gastric carcinomas.

We describe the results of the cytogenetic study of 10 primary adenocarcinomas of the stomach and one lymph node metastasis of a gastric adenocarcinoma after direct harvesting or short-term in vitro culture. All cases showed a variable number of numerical and/or structural clonal cytogenetic aberrations. Polysomy of chromosomes 2 and 20 were the most common numerical abnormalities. Rearrangements of chromosomes 1, 3, 7, and 13 were each observed in more than half the cases. Chromosomes 3 and 13 were the chromosomes more often exhibiting structural cytogenetic aberrations. In five tumors, rearrangements of chromosome 6 resulting in partial deletion of 6q were noted (common deleted region 6q21-22-->qter). The recurrent markers observed in our series were an i(8q) and an i(17q) in three and two cases, respectively. Double minutes (dmin) or homogeneously staining regions (hsr) were evident in three tumors. Contrary to the recent claim that structural abnormalities affecting 11p13-p15 were specifically involved in gastric cancer, we detected rearrangements of this region in only two cases.

Adenocarcinoma↗
PubMed1993

Cytogenetic findings in 18 follicular thyroid adenomas.

Cytogenetic study of 18 follicular thyroid adenomas showed clonal chromosome changes in 12 tumors. These results suggest the existence of at least three cytogenetically distinct subgroups: a hyperploid group characterized by the presence of a cluster of numerical changes including +5, +7, and +12 as the most frequent anomalies and, less frequently, +4, +9, +14, +16, and +17; a pseudo- or near-diploid group characterized by simple karyotypic aberrations; and a cytogenetically normal group.

Adenoma↗
PubMed1993

Thyroid nodular hyperplasia: chromosomal studies in 14 cases.

Cytogenetic study of 14 thyroid nodular hyperplasias revealed a hyperdiploid karyotype in two cases (14%) and a normal chromosomal complement in the remaining cases. Some of the numerical alterations found were identical to the ones considered characteristic of a subset of thyroid adenomas (+5, +7, +9, +12, +14, and +16). Our findings suggest that the cytogenetic events involved in the pathogenesis of thyroid hyperplastic lesions and benign tumors may be closely related, which supports the hypothesis of a biologic "continuum" between these two types of lesions.

Adult↗
PubMed1992

Loss of Y chromosome in gastric carcinoma. Fact or artifact?

Loss of chromosome Y has been reported in gastric cancer cells together with other chromosomal abnormalities. We noted loss of chromosome Y and near-diploid karyotypes in five cases of gastric adenocarcinoma, but DNA flow cytometry performed on fresh tumor tissue showed aneuploid peaks in four of them. Our findings suggest that loss of the Y chromosome in gastric cancer probably reflects the karyotype of a subpopulation of stromal cells and not a neoplasia-related chromosomal aberration.

Adult↗
PubMed1992

Clonal cytogenetic abnormalities and telomeric associations in a fibroxanthoma of the stomach.

A cytogenetic study of a fibroxanthoma (fibrous histiocytoma) of the stomach revealed a clonal structural abnormality involving chromosome 12 and frequent telomeric associations between the short arm of chromosome 12 and different chromosomes. A marker chromosome possibly derived from chromosome 11 was also present. This is the second reported case of gastric fibroxanthoma and the first studied cytogenetically.

Adult↗
PubMed1992

c-erbB-2 expression in primary gastric carcinomas and their metastases.

In an attempt to evaluate the relationship between c-erbB-2 expression and/or gene amplification, DNA ploidy and morphology, wall penetration, lymphatic permeation, and vascular invasion, we studied a series of 87 primary gastric carcinomas and their respective metastases (n = 335) using immunohistochemistry and performed DNA analysis of 30 primary tumors and 10 metastases from eight cases. Flow cytometry of fresh or frozen material was performed in 79 primary tumors. Five out of 87 primary tumors (5.7%) and 17 out of 335 lymph node metastases (5.1%) showed unequivocal membrane immunostaining for c-erbB-2. Seven out of 30 primary tumors (23.3%) showed gene amplification while amplification was identified in four out of 10 metastases (40.0%) from three patients. Eight tumors (9.2%) showed c-erbB-2 protein immunoreactivity, gene amplification, or both. One of these cases showed c-erbB-2 protein immunoreactivity only in the metastatic deposits, while gene amplification could be identified in the primary tumor. Three primary tumors showed gene amplification, but immunoreactive cells could not be identified. In no case was protein overexpression identified in the absence of gene amplification. Five cases with c-erbB-2 expression/amplification were well/moderately differentiated, and all the eight cases with c-erbB-2 expression/amplification disclosed aggressive features. Lymphatic permeation/lymph node metastases were found in all the cases and seven cases showed vascular invasion as well. In one case, there was also a liver metastasis. Two cases were early gastric carcinomas (T1sm) showing lymphatic permeation/nodal metastases and venous invasion. Six cases were aneuploid.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Signet ring cell carcinoma of the stomach: a morphometric, ultrastructural, and DNA cytometric study.

The present study was undertaken to determine whether or not signet ring cell (diffuse, isolated cell) gastric carcinomas display a specific profile at the ultrastructural, morphometric, and DNA cytometric levels. Thirty-two cases of gastric carcinoma and 8 cases of peptic ulcer (control group) were studied with electron microscopy, morphometry, flow cytometry, and image cytometry. Despite the ultrastructural cellular heterogeneity of signet ring cell carcinomas, the neoplastic cells display fairly constant morphometric features: The cellular and nuclear volumes are significantly smaller than those of the other types of gastric carcinomas and closely resemble those of normal foveolar cells. The relatively small size of signet ring cell carcinoma nuclei fits with the high percentage of the cases of this type of gastric carcinoma that are either diploid or nearly diploid. There is a relationship between the infiltrative pattern of growth of gastric carcinoma (regardless of histologic subtype and ultrastructural cell differentiation) and the small size of neoplastic cells and their nuclei.

Adenocarcinoma, Mucinous↗