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S H Hasan

Publications and source records attributed to S H Hasan.

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

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

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↗
PubMed1997

Is carcinoma breast a different disease in Pakistani population?

Carcinoma of the breast tends to be different in coloured and white races. Is this pattern also expressed in Pakistani population? To answer this query we carried out a retrospectively study of breast cancer on 193 cases who were divided into 2 groups i.e. less than and more than 50 years age groups. In the former group, 93% tumours were of grades II or III and approximately 51% were estrogen receptors negative. In more than 50 years age group, 75% tumors were in grade II and III, with almost 37% being estrogen negative tumors. Majority (75%) of the patients had over 6 cms lump with equal number having positive lymph node status. All these factors point to the fact that besides presenting late, our population has additional unfavourable prognostic factors.

Adolescent↗
PubMed1995

Reversibility of antigestagenic action of antiprogestin onapristone by exogenous progestagens during early pregnancy in guinea pig.

Ability of progesterone, gestodene, promegestone and cyproterone acetate (CPA) to reverse antigestagenic action of onapristone in adult female guinea pigs was investigated. Onapristone (10 mg/kg, s.c.) administered on post-conception days 8-11 caused resorption of implantations and vaginal bleeding in all animals. Simultaneous administration of progesterone, gestodene or promegestone on days 7-13 successfully reversed antigestagenic action of this antiprogestin, since most animals supplemented with these progestagens had viable implantations at autopsy on day 14. CPA was, however, ineffective and animals supplemented with it had only resorbed implantations and blood in uterus and vagina like that in onapristone per se treated animals. High plasma progesterone and low PGFM concentration were generally observed in all pregnant animals bearing viable implantations. PGFM (13, 14-dihydro-15-keto PGF2 alpha) was significantly elevated by day 14 in onapristone-treated (Group II) and CPA-supplemented (Group X) animals. No discernible effect on pregnancy or post-implantation embryonic development was observed in animals treated per se with these progestagens.

Animals↗
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↗
PubMed1994

Investigations on hormonal changes around parturition in the dog and the occurrence of pregnancy-specific non conjugated oestrogens.

Concentrations of progesterone and estradiol-17 beta were determined throughout pregnancy in 6 to 10 bitches (exp. 1); in experiment 2 peripartal changes of estradiol-17 beta, estrone, progesterone, cortisol, prolactin and growth hormone were determined in 5 bitches; in experiment 3 total unconjugated oestrogens were determined by radioimmunoassay and radioreceptorassay in placental tissue from 25, 53, 60 and 64 days pregnant bitches. No pregnancy specific increase of estradiol-17 beta could be observed; estradiol-17 beta levels decreased prior to parturition concomitant with the decrease of progesterone, suggesting a likewise luteal origin of estradiol-17 beta in the pregnant and non pregnant dog. Cortisol and growth hormone concentrations were elevated at the time of parturition, prolactin concentrations remained unchanged but were higher in pregnant than in non pregnant dogs. No hints in respect to a specific placental oestrogen production were obtained when examining placental tissue. The hypothesis is put forward that the high sensitivity of the haematopoietic system of the dog to oestrogen was an important factor in respect to evolution of endocrine control of pregnancy and parturition in this species which-in respect to placental oestrogen production-seems to be different from most other domestic animal species.

Animals↗
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↗
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↗
PubMed1992

Involvement of the adrenal glands in the prolactin rise induced in the female rat by an antiprogestin, onapristone.

The present study was undertaken to investigate our recent finding that the peripheral levels of prolactin are elevated after the treatment of intact tumor-bearing rats with antiprogestins, like ONAPRISTONE (ON) and MIFEPRISTONE (MI). In ovariectomized rats, s.c. administration of ON (10 mg/kg/day for 5 days) induced a significant increase in the peripheral levels of prolactin without stimulating uterine growth or suppressing LH secretion. Additionally, treatment with ON enhanced the estradiol-induced increase in the serum prolactin levels, suggesting different mechanism(s) for the effects of ON and estradiol on prolactin secretion. In the castrated animals treated with ON we also found a significant increase in the serum levels of aldosterone and corticosterone, but no measurable amount of estradiol and no significant change in the levels of serum androstenedione. Accordingly, we supposed that the effect of ON on prolactin secretion may be induced by suppression of the known activity of adrenal corticosteroids in inhibiting the prolactin secretion. In a further study using ovariectomized and adrenalectomized rats we, in fact, found no appreciable effect of ON on the serum prolactin levels at all. By contrast, dexamethasone (DEX) (0.15 mg/kg for 5 days, s.c.) significantly decreased the prolactin levels which were elevated after adrenalectomy. This effect of DEX was partially reversed by a simultaneous application of ON. From the present observations, it is anticipated that the increase in the peripheral prolactin levels found after treatment with ON is partly due to the antiglucocorticoid effect of the compound.

Adrenal Glands↗
PubMed1992

Ovarian and pituitary function in dogs after hysterectomy.

In studies of five hysterectomized and five control dogs, hysterectomy shortened the anoestrous interval (96.6 +/- 28.0 versus 149.4 +/- 50.9 days, P < 0.05). No differences in hormone concentrations (progesterone, oestradiol, prolactin and growth hormone) were observed between the control and hysterectomized dogs except for a brief fall in progesterone concentrations over 8 days immediately after surgery, between days 35 and 40 after onset of pro-oestrous bleeding; only these animals developed symptoms of overt pseudopregnancy. It is concluded that, in dogs, luteal regression occurs independently of a uterine luteolysin, but that the uterus may play a role in control of duration of anoestrus. Pseudopregnancy seems to be initiated by a fall in progesterone concentrations rather than by other hormonal changes.

Analysis of Variance↗