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A Yeldandi

Publications and source records attributed to A Yeldandi.

9 recordsLinked to original sources
PubMed2001

Follicular dendritic cell tumor presenting in the lung: a case report.

An example of extranodal follicular dendritic cell sarcoma (FDCS) presenting in the lung, a heretofore unreported site, is described. Macroscopically, a 9.5-cm, tan-white, dominant mass and multiple smaller parenchymal and pleural nodules were identified. Microscopically, the tumor was composed of spindled cells with uniform cytologic features arranged in short, intersecting fascicles and intermixed small lymphocytes and plasma cells. One of 4 peribronchial and hilar lymph nodes evaluated microscopically was focally involved by the process. Immunohistochemically, the neoplastic spindled cells expressed complement receptors CD21 and CD35 and low-affinity nerve growth factor receptor but did not express keratin (AE1/AE3 and CAM5.2), CD45 (leukocyte common antigen), CD20 (L26), S-100 protein, muscle-specific actin, or gp100 protein (HMB45). Ultrastructurally, the tumor cells have complex interdigitating cell surface processes and desmosomes. Epstein-Barr virus (EBV) was not detected in the tumor cells by in situ hybridization for EBV-encoded RNA or by polymerase chain reaction for viral DNA. FDCS should be considered in the differential diagnosis of any spindled-cell tumor with interspersed chronic inflammatory cells occurring in the lung. An immunohistochemical panel, including anti-CD21 and -CD35, can assist in its diagnosis, especially with small bronchial biopsy specimens. 2001 by W.B. Saunders Company.

Adult↗
PubMed2001

Asbestos causes apoptosis in alveolar epithelial cells: role of iron-induced free radicals.

Asbestos causes asbestosis and malignancies by mechanisms that are not fully understood. Alveolar epithelial cell (AEC) injury by iron-induced reactive oxygen species (ROS) is one important mechanism. To determine whether asbestos causes apoptosis in AECs, we exposed WI-26 (human type I-like cells), A549 (human type II-like cells), and rat alveolar type II cells to amosite asbestos and assessed apoptosis by terminal deoxynucleotidyl transferase-mediated deoxyuridine-5'-triphosphate-biotin nick end labeling (TUNEL) staining, nuclear morphology, annexin V staining, DNA nucleosome formation, and caspase 3 activation. In contrast to control medium and TiO2, amosite asbestos and H2O2 each caused AEC apoptosis. A role for iron-catalyzed ROS was suggested by the finding that asbestos-induced AEC apoptosis and caspase 3 activation were each attenuated by either an iron chelator (phytic acid and deferoxamine) or a.OH scavenger (dimethyl-thiourea, salicylate, and sodium benzoate) but not by iron-loaded phytic acid. To determine whether asbestos causes apoptosis in vivo, rats received a single intratracheal instillation of amosite (5 mg) or normal saline solution, and apoptosis in epithelial cells in the bronchoalveolar duct regions was assessed by TUNEL staining. One week after exposure, amosite asbestos caused a 3-fold increase in the percentage of apoptotic cells in the bronchoalveolar duct regions as compared with control (control, 2.1% +/- 0.35%; asbestos, 7.61% +/- 0.15%; n = 3). However, by 4 weeks the number of apoptotic cells was similar to control. We conclude that asbestos-induced pulmonary toxicity may partly be caused by apoptosis in the lung epithelium that is mediated by iron-catalyzed ROS and caspase 3 activation.

Animals↗
PubMed2001

Alveolar fluid reabsorption is impaired by increased left atrial pressures in rats.

Cardiogenic pulmonary edema results from increased hydrostatic pressures across the pulmonary circulation. We studied active Na(+) transport and alveolar fluid reabsorption in isolated perfused rat lungs exposed to increasing levels of left atrial pressure (LAP; 0--20 cmH(2)O) for 60 min. Active Na(+) transport and fluid reabsorption did not change when LAP was increased to 5 and 10 cmH(2)O compared with that in the control group (0 cmH(2)O; 0.50 +/- 0.02 ml/h). However, alveolar fluid reabsorption decreased by approximately 50% in rat lungs in which the LAP was raised to 15 cmH(2)O (0.25 +/- 0.03 ml/h). The passive movement of small solutes ((22)Na(+) and [(3)H]mannitol) and large solutes (FITC-albumin) increased progressively in rats exposed to higher LAP. There was no significant edema in lungs with a LAP of 15 cmH(2)O when all active Na(+) transport was inhibited by hypothermia or amiloride (10(-4) M) and ouabain (5 x 10(-4) M). However, when LAP was increased to 20 cmH(2)O, there was a significant influx of fluid (-0.69 +/- 0.10 ml/h), precluding the ability to assess the rate of fluid reabsorption. In additional studies, LAP was decreased from 15 to 0 cmH(2)O in the second and third hours of the experimental protocol, which resulted in normalization of lung permeability to solutes and alveolar fluid reabsorption. These data suggest that in an increased LAP model, the changes in clearance and permeability are transient, reversible, and directly related to high pulmonary circulation pressures.

Absorption↗
PubMed1997

Lymphoepithelioma-like carcinoma of the lung.

Primary lymphoepithelioma-like carcinoma of the lung is rare; only 26 case reports have been identified in the literature. The present report presents a case of a 67-year-old white man with a T1 N1 M0 lymphoepithelioma-like carcinoma of the lung. He presented with severe arthritic complaints that resolved after resection of the tumor. The majority of these tumors have occurred in Asian patients who have shown evidence of previous exposure to the Epstein-Barr virus.

Aged↗
PubMed1988

Almost total conversion of pancreas to liver in the adult rat: a reliable model to study transdifferentiation.

Study of transdifferentiation provides an excellent opportunity to investigate various factors and mechanisms involved in repression of activated genes and derepression of inactivated genes. Here we describe a highly reproducible in vivo model, in which hepatocytes are induced in the pancreas of adult rats that were maintained on copper-deficient diet containing a relatively non-toxic copper-chelating agent, triethylenetetramine tetrahydrochloride (0.6% w/w) for 7-9 weeks and then returned to normal rat chow. This dietary manipulation resulted in almost complete loss of pancreatic acinar cells at the end of copper-depletion regimen, and in the development of multiple foci of hepatocytes during recovery phase. In some animals, liver cells occupied more than 60% of pancreatic volume within 6-8 weeks of recovery. Northern blot analysis of total RNA obtained from the pancreas of these rats revealed the expression of albumin mRNA. Albumin was demonstrated in these pancreatic hepatocytes by immunofluorescence. The advantages of this model over the previously described models are: a) low mortality (10%), b) depletion of acinar cells, and c) development of multiple foci of hepatocytes in 100% of rats.

Animals↗
PubMedDate not supplied

Expression of Das-1 in primary lung adenocarcinomas represents reactivation of an oncofetal pulmonary antigen.

OBJECTIVE: The monoclonal antibody (mAb) designated as mAb Das-1 was generated against a colonic epithelial protein. It reacts with bronchiolar epithelium and submucosal glands and weakly with alveolar lining cells of fetal lung. Adult alveolar epithelium is, however, nonreactive for mAb Das-1. The present study was designed to evaluate the immunoexpression of Das-1 and to correlate it with the histomorphology of primary lung adenocarcinomas and intestinal metaplasia. METHODS: Eighty-four cases of primary lung adenocarcinomas were reviewed and categorized according to histologic grade and subtype. Immunohistochemical staining with mAb Das-1 was performed with normal colon as control. RESULTS: Expression of Das-1 in the submucosal bronchial glands also served as internal control. Strong and diffuse staining was seen in 33 of the 84 cases of adenocarcinomas (39%). CONCLUSIONS: Expression of Das-1 was seen in primary lung adenocarcinomas even though adult alveolar epithelium is negative. Staining with mAb Das-1 was seen regardless of the grade or histological subtype of the lung adenocarcinomas. As most primary lung adenocarcinomas are not of bronchial gland origin, expression of Das-1 represents activation of oncofetal antigens.

Adenocarcinoma↗