Search PubMed⌕ Search

Biomedical subjects

H Salazar

Publications and source records attributed to H Salazar.

At least 37 records · Page 2Linked to original sources
PubMed1995

The differential expression of N-cadherin and E-cadherin distinguishes pleural mesotheliomas from lung adenocarcinomas.

Malignant mesotheliomas are highly aggressive tumors that develop most frequently in the pleura of patients chronically exposed to asbestos. The distinction between malignant mesotheliomas and tumors of epithelial origin, particularly peripheral lung adenocarcinoma, can be difficult despite the use of immunocytochemical markers and other diagnostic tools. During embryonic development the cadherin cell-cell adhesion molecules participate in the segregation of cells into different tissues. As a result of complex mechanisms of tissue selectivity, N-cadherin is expressed by the developing pleural mesothelial cells and E-cadherin is expressed by the epithelial cells of the lung. Thus, we postulated that N-cadherin could be used as a marker of mesothelial cells and mesothelial tumors, in contrast to adenocarcinomas of the lung that are tumors of epithelial origin. We studied the expression of N-cadherin, E-cadherin and two cadherin-associated proteins, alpha-catenin and beta-catenin, in 19 pleural mesotheliomas, 16 lung adenocarcinomas and in 2 mesothelioma cell lines using specific monoclonal antibodies and immunohistochemical methods. Our results show that all mesotheliomas express high levels of N-cadherin, regardless of their histological type, in contrast to lung adenocarcinomas which expressed E-cadherin but no N-cadherin. The cadherin-associated proteins, alpha-catenin and beta-catenin, were present in both mesotheliomas and adenocarcinomas. Our results show that pleural mesotheliomas can be distinguished from lung adenocarcinomas based on the differential expression of N-cadherin and E-cadherin, using specific monoclonal antibodies and immunocytochemistry.

Adenocarcinoma↗
PubMed1995

A pilot study of preoperative chemoradiation for patients with localized adenocarcinoma of the pancreas.

BACKGROUND: We hypothesized that delivering adjuvant radiotherapy (RT) preoperatively with chemotherapy might enhance local control of the cancer and patient tolerance for the intervention. METHODS: Thirty-four patients with localized pancreatic cancer (24 head, 8 head and body, 2 body and tail) were treated during the past 6 years with an intramural protocol consisting of 5-fluorouracil (1,000 mg/m2 on days 2 to 5 and 29 to 32) and mitomycin-C (10 mg/m2 on day 2) given with preoperative external beam RT (median 5,040 cGy). Nine patients did not have surgery: 1 refused, 1 died of cholangitis, and 7 were noted to have distant (5) or unresectable local cancer (2) after RT. Of the 25 patients who underwent celiotomy, 11 had liver (8) or peritoneal (3) metastases and 3 had palliative pancreatectomies (2 with liver metastasectomy and 1 with hepatic artery and portal vein replacement). The remaining 11 patients (44% of the cohort with surgery, 32% of all patients) had potentially curative (PC) resections (5 total pancreatectomy, 5 Whipple, 1 distal pancreatectomy). Median tumor diameter by computed tomographic scan was 3.75 cm (range 3 to 5) for the 11 patients who received PC resections and 4.5 cm (range 3 to 7.5) for all patients. Of the 11 patients with PC resections, 8 had evidence of superior mesenteric, portal or splenic venous involvement and 4 had been deemed unresectable at previous celiotomies. RESULTS: One patient developed respiratory failure and one died postoperatively, yielding a 9% rate of major morbidity and mortality. Median follow-up of the surviving patients with curative resection is 33 months (range 14 to 70). Their median survival from the time of tissue diagnosis is 45 months with a median disease-free survival of 27 months. The product limit estimate of 5-year survival is 40% (95% confidence bounds +29%, -30%). One patient had a microscopically positive resection margin, which was a falsely negative frozen section margin at the pancreatic neck. Two patients had positive regional lymph nodes. Five patients have been diagnosed with recurrent cancer. Only 1 has had a local/regional component to the recurrence. CONCLUSIONS: Preoperative RT and chemotherapy followed by resection is well tolerated and safe for patients with locally advanced pancreatic cancer. This approach provides tumor free resection margins and offers prolonged survival to patients with truly localized pancreatic cancer.

Adenocarcinoma↗
PubMed1994

Spontaneous transformation of rat ovarian surface epithelial cells results in well to poorly differentiated tumors with a parallel range of cytogenetic complexity.

We previously used rat ovarian surface epithelial cells subjected to repetitious growth in vitro to provide experimental evidence in support of a role for incessant ovulation in the etiology of ovarian cancer. We have now initiated a series of 30 independent rat ovarian surface epithelial cell lines. This report describes findings in eight of the cell lines that, based on tumor formation in athymic mice, have undergone malignant transformation. Each of the tumors exhibited chromosomal alterations. Two well to moderately differential tumors had only one or two cytogenetic changes, and they had in common the presence of numerical gains. Each of five poorly differentiated tumors had complex karyotypes with three to eight clonal aberrations, prominent among them being unbalanced rearrangements and numerical losses. Several poorly differentiated tumors also had marker chromosomes, double minutes, or homogeneously staining regions. These findings demonstrate that the malignant tumors produced by spontaneously transformed rat ovarian surface epithelial cell lines range in degree of differentiation, which is paralleled by the cytogenetic complexity. Thus, this model system may fill an important void in future efforts to define the genetic basis of common epithelial tumors of the ovary and many features characteristic of these neoplasms.

Adenocarcinoma↗
PubMed1990

Influence of histological features and treatment on the prognosis of patients with cervical cancer metastatic to pelvic lymph nodes.

Ninety-seven patients with stage IB through IIB cervical cancer metastatic to pelvic lymph nodes treated at Magee-Womens Hospital, Pittsburgh, Pennsylvania, between 1955 and 1979 were analyzed retrospectively to determine histological factors which might predict treatment failure. All patients were treated by radical hysterectomy with a pelvic lymphadenectomy (S) or in combination with radiation therapy (S + RT) (27 and 73%, respectively) and were followed for a minimum of 5 years or until death. There were no significant differences between the two treatment groups when compared for patient age at diagnosis, distribution of disease stages, cell type, and tumor differentiation. The groups were dissimilar only with respect to the number of lymph nodes found to contain metastatic carcinoma. Significantly more patients treated by S + RT than by S alone were found to have metastasis to more than one node. Of patients treated with S alone, 65% recurred within 5 years compared with 51% with the addition of RT (P less than 0.16). The extent of both lymphocytic and polymorphonuclear infiltration of the tumor did not influence the probability of recurrence following treatment; however, tumors with a marked eosinophilic infiltration recurred significantly more frequently than those without (P less than 0.05).

Combined Modality Therapy↗
PubMed1984

Ultrastructural diagnosis in gynaecological pathology.

This chapter presents a brief description and discussion of some of the most representative examples of neoplastic and non-neoplastic lesions of the female genital system, in which electron microscopy and ultrastructural analysis may play a significant diagnostic role. The contribution of ultrastructural data in the accurate diagnosis of ovarian neoplasms, particularly the less differentiated ones, is evident and would eventually ensure the proper management of the patients. Similar considerations are explored in the analysis of fine structural studies for the differential diagnosis of lesions of the uterus, vagina and vulva, not only neoplastic but also pseudo-tumoral and inflammatory. In conclusion, electron microscopy represents a very important resource in the modern armamentarium of techniques and approaches available to the general surgical pathologist and the gynaecological pathologist for the diagnostic study of lesions of the female genital system.

Carcinoma↗
PubMed1981

Intramuscular angiomatosis of pelvic wall complicating pregnancy. Clinical, histological, and ultrastructural observations.

This is the first report of intramuscular angiomatosis involving the right bulbocavernous muscle in a pregnant woman, who underwent a cesarean section because of the risk of dystocia. The tumor was formed by well- and poorly differentiated vessels infiltrating the skeletal muscle fibers, which showed various degrees of degeneration. On electron microscopy, the neoplastic vessels were formed by large endothelial cells rich in organelles, limiting a luminal space and surrounded by a multilayered basal lamina. Pericytes were usually present around the endothelial layers. The neoplastic vascular structures seemed to grow by a process of gemmation. Our observations confirm the notion that this kind of benign neoplasm may pursue a rapidly growing course and presents a disturbing histological appearance which requires proper interpretation and precise diagnosis.

Adult↗
PubMed1980

Prolactin-secreting pituitary adenomas: serum and tissue prolactin levels with ultrastructural correlation.

Adenomatous tissue was obtained from 10 women with evidence of prolactin-secreting pituitary adenoma at the time of transsphenoidal removal of the tumor. Tissue levels of prolactin (hPRL) were estimated after extraction and were compared to preoperative peripheral serum levels of hPRL. No correlation was found between the tissue and serum concentrations of hPRL, although high levels of hPRL were found in the tissue extracts. Electron microscopy confirmed active secretion of the individual cells, and the ultrastructural findings were compatible with prolactin-secreting adenomas. Associated with the active secretion was extensive exocytosis of the secretory granules away from the capillary wall. These findings suggest that, although active secretion of hPRL is occurring, large amounts of secreted hPRL are not available for immediate uptake into the capillary plexus; thus a slow absorption of hPRL could be taking place from the adenomatous tissue. These data could explain the failure of provocative tests of hPRL stimulation and inhibition to unequivocally characterize an adenoma in an individual with elevated serum levels of hPRL.

Adenoma↗
PubMed1979

Massive ovarian edema: a nonneoplastic pelvic mass of young women.

Two cases of massive ovarian edema are reported in addition to the eight previous cases published in the English literature. The predominance of the right-sided involvement and the histopathological characteristics of this lesion support the hypothesis that the basic pathogenetic mechanism is an impairment of the venous and lymphatic drainage of the ovary, triggered by recurrent partial torsion of the mesovarium. This nonneoplastic lesion should be recognized as a distinct entity in ovarian disease and treated conservatively.

Adolescent↗
PubMed1978

Malignant meningioma: ultrastructure and observations on histogenesis.

A malignant meningioma was studied by light and electron microscopy. Histologically, the tumour was composed predominantly of spindle shaped cells arranged in interlacing bundles with numerous mitoses and much nuclear atypia. There were many necrotic foci as well as invasion of the cerebral cortex, dura mater and blood vessels. Ultrastructurally, the main findings included moderate plasma membrane interdigitation, many intracytoplasmic filaments, and junctional attachments of three kinds: desmosomes, hemidesmosomes, and zonulae adhaerentes. These subcellular features are suggestive of arachnoidal cell origin.

Cerebral Cortex↗
PubMed1977

Tubular carcinoma of the breast. Clinical, histological, and ultrastructural observations.

Tubular carcinoma is a neoplasm with good prognosis of features that warrant its differentiation from other mammary carcinomas and from sclerosing adenosis. Cases of nine primary unilateral neoplasms are presented and ultrastructural observations in three discussed. The mean diameter was 1.2 cm and the mean patient age was 48.7 years. None of the patients died and only one of six had residual tumor in the mastectomy specimens. Three patients had an excisional biopsy, one followed by radiation. All biopsy specimens showed infiltrating angular tubules with single-lining epithelium, minimal anaplasia, rare mitosis, and scant or absent myoepithelium. The tumor cells related to each other by desmosomes, cytoplasmic interlocking processes, and tight junctions. Myoepithelial cells were rare. Since tubular carcinomas are distinct variety of ductal epithelial neoplasms of the breast, and are well differentiated with low malignant biological behavior, a less radical approach may be the treatment of choice.

Breast↗
PubMed1975

Ultrastructure of the human mammary gland. II. Postpartum lactogenesis.

The history and fine structure of 7 human mammary glands were studied in the post partum. Widespread hypertrophy and hyperplasia of the mammary acini were observed accompanied by dilatation and engorgement of the lumen by milk. Loose strands of connective tissue surrounding the mammary lobules and ductules contained dilated, engorged vascular channels. The lactogenic epithelial cells displayed rich cytoplasm containing prominent layering stacks of rough endoplasmic reticulum closely related to the enlarged oval mitochondria, on occasion surrounding their entire circumference. Also noted were numerous ribosomes and polyribosomes. The markedly hypertrophied golgi apparatus revealed cisternae containing particulate electron dense material and vesicles with dense granules. The latter were frequently seen being discharged in the lumen devoid of limiting membrane. Abundant fat droplets were present in the basal and apical regions and "pinched off" into the lumen, apparently surrounded by a limiting membrane. The lactogenic cells were richly endowed with slender microvilli in their luminal pole and related to one another by cytoplasmic prolongations, desmosomes and tight junctions. The myoepithelium was stretched and thinned out toward the periphery of the acini between the lactogenic epithelium and the basement lamina. Abundant myofilaments were present in the myoepithelial cells. Pinocytotic vesicles were also present, although not very numerous, in both the lactogenic and the myoepithelial cells. In general the human mammary gland during lactopoiesis follows similar structural changes as those previously described in other mammals.

Biopsy↗