Biomedical subjects

P Validire

Publications and source records attributed to P Validire.

62 records · Page 4Linked to original sources

PubMed1991

Association of Ki-ras mutation with differentiation and tumor-formation pathways in colorectal carcinoma.

The occurrence of a point mutation on the 12th and 13th codons of the Ki-ras oncogene has been investigated in 99 colorectal carcinomas in relation to 3 histological parameters: extent of differentiation, occurrence of a mucinous component within the tumor, and presence of peripheral adenomatous polyp remnants. The mutation frequency increased with each parameter: from 13% (2/15) to 44% (37/84) with differentiation, from 33% (26/79) to 65% (13/20) with mucinous character, and from 27% (15/56) to 56% (24/43) with the presence of polyp remnants. The frequency was highest in well-differentiated mucinous tumors with adenomatous remnants 83% (5/6). We suggest that Ki-ras mutation is preferentially involved in carcinomas that have developed from adenoma and that the mutation preserves differentiation and mucin secretion in these cancer cells.

Adenocarcinoma, Mucinous↗

PubMed1991

Leydig cell tumor of the testis: a case diagnosed by fine-needle sampling without aspiration with histologic, immunohistologic, and electron microscopic analysis.

Fine-needle sampling without aspiration was performed in a patient with a testicular mass. The cytologic diagnosis was consistent with Leydig cell tumor. Cytologic features included abundant grey-blue cytoplasms with spherical or oval nuclei in May-Grünwald-Giemsa-stained smears. Intranuclear inclusions were observed but no Reinke's crystals were detected. Histologic findings confirmed the diagnosis and tumor cells were positive for vimentin. Electron microscopic analysis of the tumor showed abundant smooth endoplasmic reticulum and mitochondria with tubulovesicular cristae but no Reinke's crystals.

Adult↗

PubMed1990

Oncogene amplification correlates with dense lymphocyte infiltration in human breast cancers: a role for hematopoietic growth factor release by tumor cells?

One hundred six primary breast cancer samples were analysed for c-erbB2, int-2, and c-myc gene amplification. Surgically confirmed nodal involvement was observed in 42%. Level of gene amplification was studied by Southern and/or slot blot techniques. Amplified c-erbB2 gene sequences were present in 21.5% of all samples. Int-2 was amplified in 13.1% and c-myc was amplified in 10.3%. In a non-parametric test (Kruskal-Wallis) a strong negative association was found between high levels of c-erbB2 amplification and absence of estrogen receptor (ER) (P = .0009) or progesterone receptor (PR) (P = .011) expression. No correlations were found between all or high levels of amplification of each oncogene separately or combined with T, N, grade, multifocality of tumor, or associated carcinoma in situ. There was a trend approaching statistical significance for patients with c-erbB2 amplifications to have positive lymph nodes at surgery (P = 0.09). A somewhat surprising finding however was a very strong association between oncogene amplification and dense lymphocyte infiltration of the tumor (P = .05). This correlation is even stronger when only high levels of amplification are considered, either for each oncogene separately (P = .0048) or in combination (P = .0007). We propose that malignant cell cytokine production may help explain this observation.

Breast Neoplasms↗

PubMed1989

Multiple genetic alterations in distal and proximal colorectal cancer.

Multiple genetic alterations were investigated in colorectal cancer, including changes in DNA content, mutations in ras oncogenes, and deletions involving chromosomes 5, 17, and 18. A non-random association of deletions and mitotic abnormalities by site was seen, with both types of alterations occurring significantly more frequently in distal tumours. In contrast, the frequency of c-Ki-ras mutations did not differ between proximal and distal cancers. In addition, deletions were significantly associated with each other and with change in DNA content. The data provide strong support for the hypothesis that proximal and distal colon carcinoma might differ in the genetic mechanisms in their initiation and/or progression.

Adenocarcinoma↗

PubMed1989

Long term bone marrow culture in metastatic neuroblastoma.

We have developed a long term marrow culture assay for the study of advanced bone marrow metastatic neuroblastoma. In this in vitro system the hemopoietic growth (GM-CFU) is not affected by the presence of tumor cells. The neuroblastoma cells grow and differentiate partially when in contact with the stromal layer, arresting the culture. We present culture and histological data suggesting that the solid tumors interact specifically with the stromal layer of marrow origin.

Bone Marrow↗

PubMed1986

[Heterotopic segmental autotransplantation of the pancreas with digestive system anastomosis in the dog].

Segmental autotransplantation of pancreas in the heterotopic position, with digestive anastomosis protected by an epiploplasty was performed in a series of 22 dogs. Twenty dogs survived the operation and nine were followed up for 4 weeks: the histologic and morphologic qualities of the graft were very favorable from both endocrine and exocrine points of view. This morphohistologic quality can be related to the digestive anastomosis performed, which failed to provoke any specific complications to a large extent. This study should be completed by improvement in the vascularization of the graft by a splenic arteriovenous fistula and a concomitant study of the endocrine function of the transplanted pancreas in dogs with experimentally-induced diabetes.

Animals↗

PubMedDate not supplied

Human endometriosis-derived permanent cell line (FbEM-1): establishment and characterization.

A human epithelial-like cell line derived from peritoneal implants from a patient with gonadotrophin-releasing hormone (GnRH) agonist-resistant endometriosis graded as stage IVd according to the American Fertility Society classification was established in vitro. This cell line, designated FbEM-1, exhibited an epithelial-like morphology, grew in suspension and was immunoreactive for cytokeratins 8, 18, 19, vimentin and human leukocyte class I antigens. The cultured cells were negative for various haematopoietic cell markers, including the lymphoid cell antigens CD3, CD20 and CD45, von Willebrandt factor, carcinoembryonic antigen and the carcinoma antigen-125 (CA-125). In addition, the FbEM-1 cells were found to be moderately positive for periodic acid Schiff's (PAS) solution but were negative for alpha-naphthyl acetate esterase, peroxidase and chloroacetate esterase activities. Using specific antibodies against the progesterone, androgen and oestrogen receptors, approximately 40% and 5-10% of the cells immunostained for progesterone and androgen receptors respectively, while oestrogen receptors were not detected. On cytogenetic analysis using R-banding, these cells showed numerous chromosomal aberrations, including loss of one chromosome X, 4q+, 5q+, trisomy 7,8 and 10 and tetrasomy of chromosomes 17, 18, 19 and 20. These data show that the continuously growing FbEM-1 cell line established from endometriotic implants may be useful in achieving better understanding of the histogenesis of endometriosis.

Animals↗

PubMedDate not supplied

Comparison of the prognostic value of Scarff-Bloom-Richardson and Nottingham histological grades in a series of 825 cases of breast cancer: major importance of the mitotic count as a component of both grading systems.

The most commonly used system in Europe for breast carcinoma was developed by Scarff, Bloom and Richardson (SBR). It was recently modified by Elston and Ellis and significant improvement in reproducibility has been shown by using precise grading guidelines. This study investigated whether the use of this new grade (defined as the Nottingham grade, NG) would improve the prognostic stratification of patients. The respective prognostic value of the two grading schemes was compared in a retrospective series of 825 patients uniformly treated for a small invasive breast carcinoma and followed for a median of 6 years. Univariate and multivariate analysis showed that both histological grades were strongly correlated to overall and metastasis free survival. We have separately analysed the prognostic value of each of the three components used to assess the two grading systems and found that the mitotic index was the only significant prognostic factor for 5 year survival. Univariate analysis showed the count to be more discriminant in the NG scheme (p = 0.0006) than in the SBR scheme (p = 0.04). However, in univariate and multivariate analysis, the prognostic value of the global NG was not significantly better than SBR grade. This may be related, in part, to an uneven distribution of cases reflected by a much lower number of cases with a high mitotic index in the NG system (2%) than in the SBR system (10%). Our study emphasizes the importance of the mitotic count in assessing the prognosis of breast cancers and indicates that the factors which condition this count (tissue processing, microscopic observation, threshold) must be well standardized and controlled.

Adult↗