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Biomedical subjects

F Moatamed

Publications and source records attributed to F Moatamed.

35 records · Page 2Linked to original sources
PubMed1984

Electron microscopy in small cell lung carcinomas: clinical correlation.

In order to investigate the relationship of subcellular differentiation of small cell lung carcinomas (SCLC) and clinical response, we reviewed the electron microscopic (EM) features of tumor biopsy specimens from 33 patients with SCLC diagnosed by light microscopy (LM). These tumors were divided by EM into four groups according to the ultrastructural features. Group I (13 patients) had tumors with only neurosecretory granules on EM. Group II (11 patients) had tumors with neurosecretory granules and other subcellular features of non-SCLC. Group III (five patients) had tumors that lacked neurosecretory granules but contained subcellular features of non-SCLC. Group IV (four patients) had tumors that lacked all of these features. The complete and partial response rate to systemic chemotherapy with or without radiation therapy was 88% in the total population studied. The response rates were not statistically different in any of the four groups based on EM findings. The results of this study suggest that the LM diagnosis of SCLC alone adequately identifies lung cancer patients with a high response rate to systemic therapy.

Adult↗
PubMed1983

Acute interstitial nephritis associated with chronic active hepatitis.

Chronic active hepatitis has been associated with renal abnormalities and immune-mediated glomerulonephritis or vasculitis. We report a case of acute reversible renal failure due to renal interstitial infiltration by lymphocytes, plasma cells, and neutrophils. The acute renal failure responded to the administration of prednisone. It is possible that interstitial nephritis is commonly associated with acute and chronic hepatitis.

Acute Disease↗
PubMed1982

Immunopathology of rheumatic pericarditis.

Immunologic mechanisms have been implicated in the endocarditis, myocarditis, and arthritis of acute rheumatic fever. However, pericarditis, a major manifestation of acute rheumatic fever with a clinical incidence of 5-10%, has not been studied. We have evaluated a patient who had this febrile disease with arthritis and pericarditis. Pericardial tissue showed extensive deposition of IgG, IgM, and C3 both on the pericardial surface and within the walls of pericardial blood vessels. Our findings of immunoglobulins and complement within the inflamed pericardium suggest an immune-mediated mechanism for the pericarditis of acute rheumatic fever.

Adult↗
PubMed1981

Characterization of a variety of standard collagen substrates: ultrastructure, uniformity, and capacity to bind and promote growth of neurons.

Collagen substrates were characterized after preparation by the four methods most commonly used for tissue culture (saline precipitation, exposure to ammonium hydroxide vapor, exposure to ultraviolet light, and air drying). Although roughly equivalent percentages of collagen were precipitated by each technique (87 to 97%), marked differences were found in surface uniformity and ultrastructure. Substrates were quite uniform if precipitated by exposure to ammonium hydroxide or ultraviolet light, of intermediate uniformity if saline precipitated, and not at all uniform if air dried. Scanning electron microscopy revealed that (a) ammonium hydroxide and saline precipitation primarily resulted in formation of collagen fibrils, (b) air drying produced a small number of fibrils plus a large amount of amorphous material, and (c) exposure to ultraviolet light only resulted in the formation of globular, nonfibrillar collagen aggregates. The capacity of collagen substrates to bind and grow neurons differed markedly with the method of preparation and the amount of collagen plated per unit area. Quantifications of binding and growth of both cerebral and sympathetic neurons revealed that these are separate measures of the biocompatibility of a surface and that growth was uniformly inferior on globular collagen that had been precipitated by ultraviolet light. Long-term (greater than or equal to 2 wk) growth of sympathetic neurons was optimal on thick beds of saline-precipitated collagen, whereas short-term growth was best on thin layers of either saline or ammonium hydroxide-precipitated collagen. Cerebral neurons bound and grew optimally on thick collagen beds after both short- and long-term culture. In addition, cerebral neurons were found to be more dependent on the method of precipitation of the thin collagen substrates than were sympathetic neurons.

Ammonium Hydroxide↗
PubMed1975

Early cellular responses to mitogens and adjuvants in the mouse spleen.

The purpose of this study was to evaluate the cellular events in the spleens of mice following the intravenous injection of mitogens and adjuvants. The compounds used were concanavalin A, polyadenylic polyuridylic acid, beryllium sulfate, bacterial endotoxin, tuberculin-purified protein derivative, and dextran sulfate. Nine different strains of mice (some deficient in the C5 component of complement) received a single dose of these compounds, and their spleens were studied at sequential time intervals, ranging from 1 hour to 14 days. Concanavalin A triggered marked blast activity in the T cell zones of the splenic white pulp which was maximal at 24 hours following the injection. -3H-thymidine incorporation increased significantly, but the number of immunoglobulin-negative cells did not increase, probably because of a concomitant loss of hematopoietic cells. Polyadenylic polyuridylic acid and beryllium sulfate produced an increase in the number of lymphocytes in the T cell zones by 12 to 24 hours, but mitotic activity was unremarkable. None of the above T cell zone changes was observed in neonatally thymectomized mice. Endotoxin, purified protein derivative, and dextran sulfate produced marked B cell zone hyperplasia. Similar histologic changes were seen in the thymectomized animals. -3H-thymidine incorporation and number of immunoglobulin-positive cells were significantly increased by 24 hours. Endotoxin and dextran sulfate in some strains of mice caused marked depletion of the T cell zones. The effects of concanavalin A, endotoxin, and dextran sulfate were unrelated to the presence or absence of C5 protein. These experiments show that (1) concanavalin A, bacterial endotoxin, tuberulin-purified protein derivative, and dextran sulfate trigger in vivo the same cellular components of the immune system as they do in vitro; (2) polyadenylic polyuridylic acid and beryllium sulfate may influence the immune system by increased localization of lymphocytes in the T cell zones.

Adjuvants, Immunologic↗
PubMedDate not supplied

Characterization of zeolite fiber sizes using scanning electron microscopy.

A synthetic zeolite and four natural zeolites from the western United States were examined for fibers using a scanning electron microscope. The distributions of fiber sizes were compared to distributions of fiber sizes of erionite and fibrous glass to determine if the fiber sizes were similar to those associated with mesothelioma in humans and animals. Fibers were abundant in two samples of natural erionite, rare in two samples of natural mordenite, and not present in the sample of synthetic mordenite. Although the majority of the erionite fibers were short (less than 8 mu long) and thicker than the tumorigenic erionite (greater than 0.25 mu wide), 6% and 11% of the fibers corresponded to fiber size categories of fibrous glass that have correlated with pleural mesothelioma production in rats. Even a single species of zeolite (erionite) is not uniform in its distribution of fiber sizes. On the basis of fiber size, these natural zeolites should be evaluated because of their potential carcinogenic risk.

Aluminum Silicates↗
PubMedDate not supplied

Electron microscopy and L-dopa reaction in the evaluation of an unusual amelanotic malignant melanoma of the neck.

A 28-year-old white man with a neck mass is described. A diagnosis of amelanotic melanoma was made by L-dopa reaction and electron microscopy. This tumor could represent a metastasis from an unknown primary or a primary that had undergone spontaneous regression. It could also be a rare primary tumor of the cervical sympathetic chain. Electron microscopy and the L-dopa reaction are emphasized as important adjuncts in the diagnoses of amelanotic melanoma.

Adult↗
PubMedDate not supplied

Detection of chromosome 11q13 amplification in head and neck cancer using fluorescence in situ hybridization.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) remains a cancer with one of the lowest five-year survival rates. Despite a better understanding of the disease and recent advances in diagnosis and treatment, survival rates for HNSCC patients have not improved. Chromosomal abnormalities are common in HNSCC, and aberrations of chromosome 11q13 have been correlated with a poor prognosis. MATERIALS AND METHODS: In this study we utilized fluorescence in situ hybridization (FISH) to determine the incidence of 11q13 amplification in twenty primary HNSCC tumors. INT-2 was used as the 11q13 probe, and 9 and 11 centromeric probes were used as controls. RESULTS: Polysomy, greater than two copies of chromosome 11, was found in 2 of 20 tumors. INT2 (11q13) amplification was found in 3 other tumors. CONCLUSIONS: These preliminary studies indicate tht analysis of a larger sample of tumors using FISH may yield important diagnostic and prognostic information about head and neck tumors.

Adult↗