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Biomedical subjects

S Muzaffar

Publications and source records attributed to S Muzaffar.

18 recordsLinked to original sources
PubMed1999

Assessment of nucleolar organizer regions (NORs) in proliferative conditions of the liver.

To overcome the diagnostic dilemma in proliferative conditions of the liver which sometimes pose a problem to the working pathologist especially when the material is inadequate, a special staining technique (AgNOR) has been applied. By using this technique, nucleolar organizer regions were counted which determine the proliferative status of the cells. This prospective study included 65 cases of randomly selected liver core and fine needle aspiration biopsies. AgNOR staining was performed on formalin-fixed, paraffin-embedded tissue sections NOR dots were counted in 100 randomly selected hepatocytes at x100 oil immersion objective, and the mean count per cell was calculated for each case. Statistical analysis was done by using the Mann Whitney U test. AgNOR count results were later compared with the histologic diagnosis. The study revealed a gradual increase in mean AgNOR counts from normal liver through cirrhosis to hepatocellular carcinoma. The difference in NOR counts was significant in these three groups. The hepatocellular carcinomas were graded according to the Edmondson-Steiner histological grading system. The Grade I hepatocellular carcinomas show AgNOR counts ranging between 5-6/cell, a score which is much higher than in the normal liver, where it ranges between 1.2-2.0/cell. This technique can be used to assess the lesions where the distinction between normal liver and Grade I hepatocellular carcinoma is difficult with the use of routine methods. AgNOR counts in normal liver and chronic hepatitis cases were insignificant, but there was an appreciable difference between cases of chronic hepatitis, cirrhosis and hepatocellular carcinoma. In view of the results of this study, the AgNOR staining method is found to be a useful diagnostic tool to differentiate between normal liver, cirrhosis and hepatocellular carcinoma and also to precisely discriminate between cases of normal liver and Grade I hepatocellular carcinoma.

Biopsy, Needle↗
PubMed1999

T cell rich B cell lymphoma (TCRBCL): study of sixteen cases with review of literature.

T cell rich B cell lymphoma (TCRBCL) is a recently described variant of diffuse non Hodgkin's lymphoma (NHL), the acronym of which has gained wide acceptance among hematopathologists in a relatively shorter period of time. The recognition of this entity requires immunohistochemical facilities especially on paraffin embedded tissues. TCRBCL is one of the many examples in the diagnostic anatomic pathology which emphasizes the need of immunocytochemistry and availability of this technique at least in referral laboratories. One of the differential diagnosis in this case includes lymphocyte predominance Hodgkin's disease (LPHD) which is the most favorable prognostic histologic subtype of Hodgkin's disease (HD) while TCRBCL is an aggressive B Cell NHL and should be treated as high grade large cell lymphoma. The other close differential includes peripheral T cell non-Hodgkin's lymphoma (PTCL). We reported sixteen (16) cases of TcRBCL diagnosed during a period of two and a half years (January 1995 to June 1997). HD and PTCL were the main differential diagnoses in most of these cases. The median age at diagnosis was 39 years and male to female ratio was equal. TCRBCL was nodal in location in 15 cases and a single case in extranodal site presenting as spinal tumor. The mean neoplastic B cell population was 12%, while that of reactive T cells was 82%. A significant polymorphous inflammatory cellular background was noted in 5 cases. Reed-Stenberg like cells were observed in 3 cases. Immunoglobulin light chain restriction studies were performed in fourteen cases and revealed lambda light chains in ten cases while in four cases kappa light chains were present.

Adolescent↗
PubMed1999

Clinico-morphological pattern and frequency of bone cancer.

OBJECTIVE: The present study was done to find out the frequency of malignant tumors of bone and to categorize the prevalence of various histological types of osseous malignancies with respect to age, sex and site of origin. SETTING: This study included consecutive cases of malignant bone tumors, which were diagnosed in the department of pathology at the Aga Khan University Hospital, Karachi during the period of three years (1995-1997). METHODS: These tumors were initially evaluated on H & E stained section from paraffin embedded tissue blocks. Special stains and immunohistochemical analysis was performed whenever required. RESULTS: A total of 169 malignant bone tumors were diagnosed during the study period. Metastatic tumors accounted for 28.4% of all malignant tumors of bone. Osteogenic sarcoma (27.2%) was the most frequent primary tumor of bone followed by Ewing's sarcoma (12.4%), Non-Hodgkin's lymphoma (10.6%), Chondrosarcoma (8.3%), Plasma Cell Myeloma (8.3%) and other rare entities (4.8%) in order of frequency. CONCLUSION: The most common malignant neoplasm diagnosed in osseous biopsies was metastatic tumors. Osteogenic sarcoma was the most frequent primary bone tumor in this series. The bone tumors were relatively more prevalent in males. The frequency of malignant bone tumor was relatively high as compared to developed countries.

Adolescent↗
PubMed1998

Diagnosis of pulmonary tuberculosis using PCR assays on sputum collected within 24 hours of hospital admission.

There have been few studies evaluating the efficacy of polymerase chain reaction (PCR) testing in front-line clinical practice. We assessed the diagnostic yield of PCR prospectively in a blinded study of patients admitted to rule out tuberculosis and compared PCR results to a culture and clinical diagnosis of tuberculosis. Specimens were sent for routine smear, culture, and PCR analysis. Sputum sediments were submitted for PCR amplification of IS6110 sequences by an in-house assay and also the Roche Amplicor PCR assay targeting 16s ribosomal RNA genes. Eighty-five patients were enrolled: 27 patients had cultures positive for tuberculosis; 12 were smear-positive. PCR by both assays on the first specimen picked up all patients smear-positive on any specimen. A positive PCR on at least one of two specimens collected in the first 24 h was 85 and 74% sensitive and 88 and 93% specific for tuberculosis by the in-house and Roche techniques, respectively. Sensitivity in smear-negative patients was 73 and 53%, respectively. The in-house PCR detected 100% and Roche detected 95% of patients with more than paucibacillary (greater than 20 colonies) tuberculosis. We conclude that PCR may be a useful tool to evaluate patients for tuberculosis within the first hospital day.

Female↗
PubMed1998

Spinal cord compression: histologic spectrum of lesions.

Histologic diagnosis ultimately determines the prognosis and treatment of lesions causing spinal cord compression. Modern imaging techniques have revolutionized the procedure of localizing lesions presenting with signs and symptoms of spinal cord compression. As a result, these lesions are more accessible for fine needle aspiration and biopsy. A quick diagnosis is possible if cytologic preparation is made. Similarly, intraoperative frozen section facility not only provides rapid diagnosis, but also offers opportunity of appropriate management decision there and then. Histology in many cases needs help of special stains and immunocytochemistry. This study looks at the histologic spectrum of these lesions, gender distribution and age range in Pakistani population.

Adenocarcinoma↗
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↗