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F A Tavassoli

Publications and source records attributed to F A Tavassoli.

113 records · Page 7Linked to original sources
PubMedDate not supplied

Mammary "comedo"-DCIS: apoptosis, oncosis, and necrosis: an electron microscopic examination of 8 cases.

The terms apoptosis and necrosis are commonly used to imply two distinct types of cell death. Apoptosis reflects a genetically mediated. ATP-dependent form of cell death. A passive form of cell death (oncosis) also occurs, often in response to some form of injury. Both pathways can lead to necrosis (postmortem autolytic cell changes). The nature of intraluminal necrosis in mammary ductal carcinoma in situ (DCIS) was evaluated using ultrastructural analysis on paraffin-embedded material of 8 cases with "comedo"-DCIS. In each case, intraepithelial proliferation zones and intraluminal zones (peripheral and central luminal zones) were examined. All cases with "comedo"-DCIS revealed abundant apoptosis, characterized by apoptotic cells showing chromatin condensation and margination with sharply circumscribed, uniformly dense crescents, as well as cytoplasmic condensation. Numerous membrane-bound apoptotic bodies with condensed cytoplasm (with or without nuclear fragments) were also observed. The central luminal zones of "comedo"-DCIS, however, revealed necrotic debris characterized by severe degradative changes, largely devoid of recognizable cell structures. In addition, two cases displayed features of oncosis, characterized by nuclear and cytoplasmic swelling, vacuolization of cytoplasm, and mitochondrial swelling with occasional dense bodies. The results indicate that necrosis (postmortem, secondary degradative cell changes) in "comedo"-DCIS is the end result of either apoptosis (programmed cell death) alone or a combination of apoptosis and oncosis (passive or "accidental" cell death).

Apoptosis↗
PubMedDate not supplied

A comparison of two commercially available in vitro chemosensitivity assays.

In vitro chemosensitivity assays (IVCAs) are expensive laboratory tests utilized to assist oncologists in the selection of chemotherapeutic regimens. Their utility is disputed; yet, these assays continue to be requested because of the importance of the information they can provide and their scientifically logical approach. Therefore, we compared the results of two assays offered to clinicians at our hospital; the extreme drug resistance assay performed by Oncotech (OT) and the fluorescent cytoprint assays performed by Analytical Biosystems (AB). The two techniques used and the expression of assay results by the two companies are discussed. Twenty neoplasms, all at least 3 cm in diameter and predominantly of breast and ovarian origin, were compared. OT performed 74 drug assays on 17 tumors, while AB performed 194 assays on the corresponding neoplasms; 3 neoplasms were insufficient for comparison. Evaluation of the results revealed apparent disagreement on at least 44 drug assays with complete disagreement on at least 2 of the drugs tested in 12 of 17 cases. In conclusion, based on available information, comparisons between IVCAs show great variation in results; prospective studies are needed to evaluate commercially available assays for correlation with clinical outcome, and results should be expressed so comparisons can be readily made. Though utility may be limited to tumors resistant to standard therapy, cost and benefit to the patient will ultimately determine the fate of these tests.

Antineoplastic Agents↗
PubMedDate not supplied

Coexistence of intracytoplasmic lumens and membrane-bound vesicles in an invasive carcinoma arising in a cystosarcoma phyllodes.

An unusual invasive breast carcinoma, arising in a cystosarcoma phyllodes and characterized by a variable cytoplasmic appearance and mucin content, was evaluated to determine the nature of the secretory material within the cells as well as the type of secretory organelle at the ultrastructural level. Histochemical studies revealed both acidic (sialic acid) and neutral mucin within the tumor cells. Ultrastructural analysis revealed secretory material within membrane-bound vesicles in some cells and within intracytoplasmic lumens in others; some cells contained both membrane-bound vesicles and intracytoplasmic lumens simultaneously. The Golgi derivation of the intracytoplasmic lumens was supported by their presence within or near hyperplastic Golgi complexes. The histochemical characteristics of the secretory material is correlated with their ultrastructural site of accumulation.

Aged↗
PubMedDate not supplied

Intranuclear helioid inclusions in mammary intraductal hyperplasias.

Intranuclear helioid bodies were identified by light microscopy in eight cases of mammary intraductal hyperplasia, only one of which was atypical. These structures appear as round, intranuclear eosinophilic bodies on light microscopic examination. When prominent, they may be and have been mistaken for viral inclusions. Ultrastructural analysis of these inclusions shows a single-membrane-bound structure containing a laminated or homogeneously electron-dense core with a corona of radiating filaments. In the first and only previous report of this structure in the breast, helioid bodies were identified incidentally during an ultrastructural analysis of a breast adenoma, but the light microscopic counterpart of this structure was not described or illustrated. In view of the similarity of the laminated inclusions to psammoma bodies, the possibility that helioid bodies serve as a nidus for development of microcalcification in the breast was considered. Actual microcalcification was not evident in the vicinity of any of these inclusions, however, and there was no evidence of calcification in these structures on von Kossa's stain for calcium.

Adult↗