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Biomedical subjects

S Muzaffar

Publications and source records attributed to S Muzaffar.

46 records · Page 3Linked to original sources
PubMed1997

Immunophenotypic analysis of non-Hodgkin's lymphoma.

One hundred and three cases of Non-Hodgkin's lymphoma were evaluated immunohistochemically using a panel of monoclonal antibodies which includes leucocyte common antigen (LCA), CD45R (Pan-B marker), L-26 (CD 20-Pan-B marker) and UCHL-1 (Pan-T marker). Of the total 63 cases (61.17%) showed a B-cell phenotype while 40 (38.83%) were of T-cell origin. Most B-cell neoplasms belonged to intermediate (79.36%) or high grade (15.87%) according to the International Working Formulation (WF). Most T-cell lymphomas were of either intermediate (52.5%) or high grade (32.5%) neoplasms. Some T-cell neoplasms presented as specific clinicopathological entities like lymphomatoid granulomatosis (2 cases), mycosis fungoides (1 case) and AILD type NHL (1 case). In 27 cases the immunostaining pattern of two. Pan-B markers i.e., L26 and CD45R was compared. L26 staining was expressed in all 27 cases (100% sensitivity) while CD45R showed positive reaction in 22 cases (82% sensitivity). UCHL-1 is proved to be a sensitive and lineage specific T-cell marker and in 67% cases the staining pattern was moderate (+2) to intense (+3). The mean age for the B-cell lymphomas was 49 years and 36 years in T-cell neoplasm. Male to female ratio in both types of lymphomas was 2:1. The study indicates a high prevalence of T-cell when comparing the data from western countries and lower to those from Japan and Caribbean countries.

Adult↗
PubMed1996

Nitric oxide synthase inhibition is associated with decreased survival of cardiac allografts in the rat.

Nitric oxide is a biological mediator that regulates blood vessel wall tonus, enhances macrophage cytotoxicity, and inhibits cellular immune reactivity. Primary acute rejection is associated with increased intragraft production of NO but it is unknown whether this delays or enhances the loss of graft function. The aim of the current study was to determine the effect of L-NAME, a nitric oxide synthase inhibitor, on the course and histopathology of rat cardiac allografts with primary acute rejection. L-NAME decreased the graft survival time from 9.4+/-1.5 to 6.9+/-0.3 days; the histopathology at asystole showed predominantly ischemic necrosis. L-NAME combined with antihypertensive drugs restored the rejection time (from 8.6+/-0.4 to 14.2+/-3.2 days) and resulted in an acute rejection pattern. We conclude that blocking of nitric oxide formation during acute rejection of a vascularized cardiac graft results in a decreased graft survival time and ischemic graft necrosis, very likely secondary to unopposed vasoconstriction.

Animals↗
PubMed1996

Human phagocytes employ the myeloperoxidase-hydrogen peroxide system to synthesize dityrosine, trityrosine, pulcherosine, and isodityrosine by a tyrosyl radical-dependent pathway.

Myeloperoxidase, a heme protein secreted by activated phagocytes, may be a catalyst for lipoprotein oxidation in vivo. Active myeloperoxidase is a component of human atherosclerotic lesions, and atherosclerotic tissue exhibits selective enrichment of protein dityrosine cross-links, a well characterized product of myeloperoxidase. Tyrosylation of lipoproteins with peroxidase-generated tyrosyl radical generates multiple protein-bound tyrosine oxidation products in addition to dityrosine. The structural characterization of these products would thus serve as an important step in determining the role of myeloperoxidase in lipoprotein oxidation in the artery wall. We now report the identification and characterization of four distinct tyrosyl radical addition products generated by human phagocytes. Activated neutrophils synthesized three major fluorescent products from -tyrosine; on reverse phase HPLC, each compound coeluted with fluorescent oxidation products formed by myeloperoxidase. We purified the oxidation products to apparent homogeneity by cation and anion exchange chromatographies and identified the compounds as dityrosine (3,3'-dityrosine), trityrosine (3,3',5',3"-trityrosine) and pulcherosine (5-[4"-(2-carboxy-2-aminoethyl)phenoxy]3, 3'-dityrosine) by high resolution NMR spectroscopy and mass spectrometry. Additionally, we have found that dityrosine is a precursor to trityrosine, but not pulcherosine. In a search for a precursor to pulcherosine, we identified isodityrosine (3-[4'-(2-carboxy-2-aminoethyl)phenoxy]tyrosine), a non-fluorescent product of L-tyrosine oxidation by human phagocytes. Our results represent the first identification of this family of tyrosyl radical addition products in a mammalian system. Moreover, these compounds may serve as markers specific for tyrosyl radical-mediated oxidative damage in atherosclerosis and other inflammatory conditions.

Free Radicals↗
PubMed1996

The validity of classic symptoms and chest radiographic configuration in predicting pulmonary tuberculosis.

OBJECTIVE: Patients admitted to the pulmonary isolation service to rule out tuberculosis (TB) were prospectively studied to identify predictors of smear-positive TB. METHODS: History of symptoms--cough, sputum production, fever, weight loss, night sweats, hemoptysis, anorexia, and dyspnea; medical history--TB, tuberculin skin test (TST) status, TB contact; and social factors--crowding index, history of incarceration or living in a shelter, and employment status were obtained in face-to-face interviews. Chest x-rays (CXRs) were scored as typical, atypical, or negative. Serial morning sputa were collected. RESULTS: Complete data were collected on 101 patients; 44 had pulmonary TB; 33 patients were smear positive and considered infectious; 11 patients were smear negative but culture positive. There was no difference between TB and non-TB patients with respect to HIV status and social risk factors. Significant differences were found between patients who were smear positive for TB and smear negative with respect to cough, sputum, and typical CXR (79%, 76%, and 79% sensitivity, respectively). Eleven patients without TB had an atypical CXR and denied cough, sputum, and weight loss. Only one patient with TB presented this way. CONCLUSION: Even in high-risk populations, symptoms of cough, sputum, weight loss for less than 2 weeks, and the absence of a typical CXR are strong negative predictors for TB.

Female↗
PubMed1994

Inflammatory pseudotumour of the trachea: report of a case in an eight-year-old child.

A polypoid inflammatory pseudotumour was diagnosed in the trachea of an eight-year-old child who presented with asthmatic symptoms. The tumour showed 80 per cent blockage of the lower trachea and consisted of proliferating spindly fibroblastic cells admixed with a variable number of inflammatory cells. The literature on childhood inflammatory pseudotumours is reviewed together with the differential diagnosis of other polypoid mesenchymal tumours of the trachea.

Child↗
PubMed1993

Intraoperative frozen section consultation: an analysis of accuracy in a teaching hospital.

This is a retrospective quality assurance study of all frozen sections done at The Aga Khan University Hospital during a six year period (1986 to 1991). There were 1,031 frozen sections out of a cumulative total of 42,985 surgical specimens (2.39%). Nine hundred and severity-six (94.66%) were concordant. In 92 (8.9%) fresh specimens were brought from other hospitals of Karachi, in 37 cases (3.58%) the diagnosis was deferred till the evaluation of permanent paraffin sections and 18 (1.74%) were discordant with 7 (0.67%) false positive and 11 (1.06%) false negative. Among the discordant cases, 9 were attributed to misinterpretation, 7 due to sampling errors and 2 due to technical reasons. Some of these errors might have been avoided, but appear to be an irreducible minimum.

Frozen Sections↗