Biomedical subjects

N Perez-Reyes

Publications and source records attributed to N Perez-Reyes.

6 recordsLinked to original sources

PubMed1992

Immortalization of primary human smooth muscle cells.

Primary human aortic and myometrial smooth muscle cells (SMCs) were immortalized using an amphotropic recombinant retroviral construct containing the E6 and E7 open reading frames (ORFs) of human papillomavirus type 16. The SMCs expressing the E6/E7 ORFs have considerably elevated growth rates when compared with nonimmortalized control cells and show no signs of senescence with long-term passage. The first SMC line derived in this study has been maintained in continuous tissue culture for greater than 1 year (greater than 180 population doublings). The immortalized SMCs have decreased cell size and decreased content of muscle-specific alpha-actin filaments as determined by indirect immunofluorescence. Southern blot analysis has demonstrated the stable integration of the E6/E7 ORFs in the retrovirally infected cells, and radioimmunoprecipitation has confirmed the continued expression of the E6 and E7 genes. Cytogenetic studies of the SMC lines have revealed essentially diploid populations except for the myometrial clonal line, which became aneuploid at late passage (greater than 125 doublings). These cell lines were not tumorigenic in nude mice.

Animals↗

PubMed1991

Progression of human papillomavirus type 18-immortalized human keratinocytes to a malignant phenotype.

We have developed a model system for progression of human epithelial cells to malignancy, using a human papillomavirus type 18 (HPV-18)-immortalized human keratinocyte cell line. Cells of cell line FEP-1811 were nontumorigenic in athymic mice through at least 12 passages in culture, but after 32 passages were weakly tumorigenic, producing tumors that regressed. After 62 passages they produced invasive squamous cell carcinomas that grew progressively. The progression to malignancy was associated with an increase in the efficiency of forming colonies in soft agar and with altered differentiation properties. In an organotypic culture system, FEP-1811 cells at passages 12 and 32 exhibited features typical of premalignant intraepithelial neoplasia in vivo, and cells at passage 68 exhibited features consistent with squamous cell carcinomas. No change in copy number of the transfected HPV-18 genome or in the level of expression of the viral transforming gene products E6 and E7 was detected between tumorigenic and nontumorigenic cells. Cytogenetic analysis of cells at early, middle, and late passage levels and cells cultured from tumors revealed that several chromosomal abnormalities segregated with the tumorigenic cell populations.

Animals↗

PubMed1991

Epithelial cells immortalized by human papillomaviruses have premalignant characteristics in organotypic culture.

Three HPV-16--and four HPV-18--immortalized human foreskin keratinocyte cell lines were analyzed on organotypic epidermal raft cultures at various passage levels. This culture system allowed normal cultured keratinocytes to stratify and differentiate in a manner similar to normal epidermis. All seven HPV-immortalized cell lines displayed epidermal morphologies on organotypic cultures, which were clearly abnormal and resembled premalignant lesions in vivo. Features of premalignant lesions that were shared by all of the HPV-immortalized cell lines included disorganized tissue architecture, mitotic cells present throughout the living layers of the epidermal sheet, abnormal mitoses, enlarged nuclei, and variable cell size and shape. Most HPV-immortalized cell lines were stable in terms of epidermal morphology with long-term passage in culture. Two of the HPV-18--immortalized cell lines, however, lost all morphologically apparent terminal squamous differentiation potential after long-term passage in monolayer culture. These results strongly support the idea that immortalization of squamous epithelial cells in culture by HPV-transforming genes generates a morphologically premalignant cell.

Cell Line, Transformed↗

PubMed1987

Angioinvasion in breast carcinoma. An immunohistochemical study of factor VIII-related antigen.

Histologic sections from 63 patients with infiltrating duct carcinoma of the breast were selected for study by immunohistochemical staining with antibody against human Factor VIII-related antigen. Of these 63, 30 had no lymph node metastases at the time of surgery, while 33 had axillary lymph node metastases. A positive correlation exists between the presence of vascular invasion and lymph node metastases. Sixty-nine percent of patients with lymph node metastases had vascular invasion while only 26% of patients without lymph node metastases showed evidence of invasion of blood vessels. The finding of vascular invasion by tumor in patients without axillary lymph node metastases at the time of mastectomy may explain the occurrence of disseminated disease years after treatment.

Breast Neoplasms↗

PubMed1987

Squamous cell carcinoma of head and neck in patients with well-differentiated lymphocytic lymphoma.

Seventy-six cases of well-differentiated lymphocytic lymphoma (WDLL) were reviewed for evidence of additional malignancies. Of these, 18 patients (24%) had one to three further tumors; one half (nine) had squamous cell carcinoma (SCC). The head and neck area was the primary site in all but one case of SCC. The carcinomas were frequently multiple, recurrent, and clinically aggressive. The tumors showed unusually poor differentiation histologically. Actinic keratosis and basal cell carcinomas were frequently associated with SCC. Fifty percent metastasized to cervical lymph nodes replaced by WDLL. Lymphadenopathy due to metastatic SCC may be mistaken for malignant lymphoma alone. In two of five patients (40%), death was directly attributable to SCC. As in renal transplant recipients, SCC of the head and neck in WDLL patients is a common cause of significant complications and mortality requiring aggressive management. Immunosuppression due to WDLL and/or to chemotherapy is likely an important predisposing factor in combination with sun exposure.

Aged↗

PubMed1987

Thoracic disk herniation: MR imaging.

The authors undertook a retrospective study to assess the role of magnetic resonance (MR) imaging in thoracic disk herniation. The initial MR images were interpreted independently of other findings. These interpretations were compared with the findings of plain and computed tomography (CT) myelography and surgery, when available. Sixteen thoracic disk herniations were confirmed with plain and CT myelography and/or surgery. Plain myelography was performed on 14 patients and showed focal ventral filling defects in nine. Results of CT myelography were equivalent to those of MR imaging with three pulse sequences (sagittal T1 and T2 weighted, axial T1 weighted) in the identification of all the abnormal levels. In two patients, the signal from the herniated disk was so low on all sequences that thoracic disk herniation had to be inferred from the mass effect on the spinal cord. Precise location of the abnormal level with body coil MR images was achieved in six of 13 patients.

Adult↗