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Biomedical subjects

S Pervez

Publications and source records attributed to S Pervez.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1998

Soft tissue sarcomas: pattern diagnosis or entity?

Soft tissue sarcomas (STS) are a diverse and heterogeneous group of tumours. The sub-classification of these tumours is of importance for both prognosis and treatment. Classically, sub-categorization is based purely on histomorphological grounds, but as new techniques evolve, a more conclusive and accurate diagnosis can be made. This study describes the prevalence of soft tissue sarcomas in adults diagnosed at The Aga Khan University Hospital (AKUH) and the impact of immunohistochemistry (IHC) on the precise sub-categorization of these tumours. The study included 364 adults (age 16+) who were diagnosed as soft tissue sarcoma in the past six years (May 1991-July 1997) at the Histopathology lab of the AKUH. Where indicated, tumours were stained with a panel of antibodies using the PAP technique. Of these, 237 (65%) were male and 127 (35%) were female. The median age at which all sarcomas were diagnosed was 39.5 years. The most common site was the lower extremity (29%). The most frequently diagnosed sarcoma was leiomyosarcoma (13%), followed by malignant nerve sheath tumour (12%), rhabdomyosarcoma (10%) and liposarcoma (10%). Cases were further analyzed by dividing them into two groups, each group comprised of all sarcomas diagnosed during the specified period. In the period 1991-1994, only 16% of cases were further analyzed using IHC, while in the period 1995-1997, IHC was performed on 59% of cases. In the 1991-1994 group, a conclusive diagnosis was made in 57% of the cases and in the 1995-1997 group in 78%. A Chi-square test was performed, which proved that these results were statistically significant. Soft tissue sarcoma is one of the key areas in surgical pathology where immunohistochemistry plays an important role in both precise diagnosis and sub-categorization.

Abdominal Neoplasms↗
PubMed1998

Changing patterns and re-distribution of antigen in poorly differentiated carcinomas: its implications in tumour diagnosis.

The variability of expression of tumour-associated antigens via either antigenic heterogeneity or antigenic modulation presents a basic problem in immunohistochemical diagnosis of poorly/undifferentiated tumours. This work was designed to study antigenic expression on human resected epithelial tumours by a panel of most widely used antibodies (EMA, CEA, AUAI & Cytokeratin) in relation to tumour differentiation and polarization. It was observed that poorly differentiated carcinoma with loss of polarity show homogeneous membrane staining (with antibodies against EMA, CEA & AUAI) in contrast to either apical (luminal) or basolateral membrane staining in well differentiated counterparts. Biochemical studies have shown that apical and basolateral epithelial cell membrane domains have a characteristic set of glycoproteins. Tight junctions are essential for maintaining this functional polarization. It was concluded that structural and functional abnormalities of tight junctions in poorly differentiated carcinomas results in loss of polarity with progressive invasion of the cell surface by antigenic glycoprotein and resultant homogeneous individual cell antigenic expression in poorly differentiated carcinomas. This study demonstrates that antigenic expression on tumour cells is not static, but dynamic and heterogeneity of antigenic expression may well be due to biological factors such as spatial configuration of the lesion.

Adenocarcinoma↗
PubMed1998

Diagnostic evaluation of fine needle aspiration cytology in the management of palpable breast lesions.

A total of 113 fine needle aspirates of the breast masses were evaluated in which the subsequent biopsy or mastectomy specimen were also available for histological examination. The age ranged from 16 to 80 years with a mean of 42 years. In benign conditions the mean age was 34.7 years while in malignant cases it was 48 years. The cytological diagnoses were compared with the histological results which revealed that the specificity and sensitivity of fine needle aspiration cytology in the palpable breast lesions was 86.1% and 89.2% respectively with a positive predictive value of 93% and efficiency of 88.2%. Similar statistics from other series in which the cytological results of breast lesions were compared with histological results, revealed almost same results which suggest that fine needle aspiration cytology is an effective and accurate technique for the diagnosis and management of palpable breast lumps.

Adolescent↗
PubMed1997

Management of children with acute respiratory infections (ARI) by general practitioners in Multan - an observational study.

A knowledge, attitude and practices (K.A.P.) survey was conducted among doctors working as general practitioners (GP) in Multan, for diagnosis and management of acute respiratory infections (ARI) in children under five years of age. GPs in Multan were not familiar with national ARI control programme and rational drug use guidelines. They rarely asked about symptoms describing severity of disease while taking patient histories and did not look for signs of severe pneumonia during physical examinations. Most patients diagnosed as URTI (upper respiratory tract infection) received oral antibiotics and those with pneumonia received injectable antibiotics. Other drugs prescribed included cough syrups, antihistamines and antipyretics. The average number of drugs prescribed per patient was 3.4. The doctors were deficient in providing home care advice for sick children to the caretakers. Average time spent by doctors on each patient was two minutes and twenty-three seconds. A combination of biomedical and social factors help to perpetuate this irrational prescribing behaviour of the GPs. Continuing education programmes for doctors in general practice about ARI management in children and rational use of drugs and health education of the public may improve the current prescribing practices.

Acute Disease↗
PubMed1997

Classification and immunophenotyping of acute leukemias: a prospective study.

Over a period of 3-1/2 years, 86 cases of acute leukemia were analyzed by immunohistochemical (IHC) means on ficoll separated cytospin preparations of peripheral blood and/or bone marrow samples. Antibodies included in the panel were specific against Tdt, HLA-DR, CD19/CD20/CD22, CALLA (CD10), CD2, CD11C as well as against Ig heavy chains. Of 86 cases analyzed, 48 cases were of ALL, (25 of common pre-B ALL, 15 of pre-B/NULL and 8 of T ALL phenotype), twenty-four (24) out of 86 cases were of non-lymphoblastic (AML/AMML) type. In six cases, there was suggestion of a mixed lineage, while in 8 cases there was inconclusive diagnosis. Mean age was lower in common ALL sub-set of ALL as compared to pre-B/NULL group (i.e., 8 vs 12 years), while in non-lymphoblastic group it was 36 years. T cell phenotype was invariably seen in young adults, who usually presented with a mediastinal mass.

Adult↗
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

Computed tomography appearance of malignant schwannoma of the liver.

Malignant schwannoma of the liver without associated neurofibromatosis is rare. The authors present one such case in a 35-year-old woman. Computed tomography demonstrated large liver masses with contiguous involvement of adjacent stomach tissue, consistent with local invasion.

Adult↗
PubMed1994

Immunohistochemical estrogen receptor determination in human breast carcinoma: correlation with histologic differentiation and age of the patients.

An immunohistochemical assay for the measurement of estrogen receptor (ER) has been evaluated on 290 consecutive human breast biopsy and mastectomy specimens in the year 1992 at The Aga Khan University Hospital laboratories. Immunohistochemical localization of estrogen receptor on frozen/paraffin section was scored in a semi-quantitative fashion incorporating both the intensity and the distribution of specific staining. Histologic grading of the tumour was performed according to Bloom's method. In this study, 21% of the tumours were estrogen receptor negative, 15% were weak positive, 25% intermediate positive and 39% strong positive. Fifty percent of the well differentiated tumours showed strong ER positivity against 27% of the poorly differentiated tumours. Seventy eight percent of all negative estrogen receptors were in patients younger than 50 years of age (pre-menopausal group), while 52% of strong estrogen receptor positivity was observed in patients older than 50 years (post- menopausal). This study demonstrates the value of immunohistochemical method to determine the ER status in patients with advanced breast cancer.

Adult↗