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Biomedical subjects

K Hassan

Publications and source records attributed to K Hassan.

At least 37 records · Page 2Linked to original sources
PubMed1998

Cutaneous malignant melanoma in women and the role of oral contraceptives.

The role of oral contraceptives (OC) in the aetiology of cutaneous malignant melanoma (CMM) has been controversially discussed over the last two decades. In an extensive literature search we identified 18 case-control studies, published between 1977 and 1996, offering information on this relationship. Using a meta-analytical approach we combined the study-specific risk estimates and derived a summary odds ratio of 0.95 (95% confidence interval: 0.87-1.04). Based on the data of 3796 cases and 9442 controls, we thus found no evidence for an aetiological role of OC use in the development of CMM.

Case-Control Studies↗
PubMed1997

Factors associated with anemia in refugee children.

A nutrition survey was performed in 1990 among children 6 through 35 mo of age living in Palestinian refugee camps in Syria, Jordan, the West Bank, Gaza Strip and Lebanon. Overall, 67% [95% confidence interval (CI): 66, 68] were anemic (hemoglobin <110 g/L), ranging from 54% in the West Bank to 75% in Syria. The following factors were significantly associated with anemia in one or more of three age groups (6-11.9, 12-23.9 and 24-35.9 mo) by logistic regression: living in Syria, Lebanon, or Gaza [with prevalence odds ratios (POR) in the range of 1.4-2.6 depending on the age group and area, relative to children living in Jordan]; never having been breast-fed (POR = 1.7); male sex (POR = 1.2); maternal illiteracy (POR = 1.4 relative to those with >/=6 y of education); having a recent (within 2 wk) or current episode of fever or diarrhea; and stunting. Recent or current illness and stunting interacted in two age groups with the general trend of stunted children with recent or current illness having high POR. Early childhood anemia is associated with factors reflecting poor socioeconomic status and recent diarrheal and febrile illnesses in Palestinian refugee camps.

Aging↗
PubMed1997

Systematic review of case-control studies: oral contraceptives show no effect on melanoma risk.

BACKGROUND: Parallel to the rising incidence of malignant melanoma in fair-skinned populations, intensive efforts are currently devoted to identifying risk factors for melanoma in addition to the well-known cutaneous factors and those variables related to UV-exposure. OBJECTIVE: Systematic review of published results to elucidate the role of oral contraceptives in the development of malignant melanoma. DATA SOURCES: Literature retrieval systems MEDLINE and CANCERLIT as well as reference lists of already collected studies. STUDY SELECTION: All 18 (non-duplicate) case-control studies on the above relationship. DATA EXTRACTION: From the published data, study-specific odds ratios (OR) and accompanying confidence intervals (CI) were recalculated. For a quantitative meta-analytical summarisation two different models have been applied: a "fixed effects" (FE) and a "random effects" (RE) model. DATA SYNTHESIS: Study-specific ORs ranged from 0.13 up to 1.85; however, the majority of studies (14 of 18) yielded similar ORs within the interval [0.82, 1.15]. The summary ORs estimated from FE- and RE-models were both 0.95 (95% CI: [0.87, 1.04] for the FE-model, [0.87, 1.05] for the RE-model). CONCLUSION: The systematic review of case-control studies revealed no evidence for an aetiological role of oral contraceptives in the development of malignant melanoma.

Case-Control Studies↗
PubMed1995

Expression of beta-galactosidase in neurons of dorsal root ganglia which are latently infected with herpes simplex virus type 1.

Explanation into culture of dorsal root ganglia (DRG) latently infected with herpes simplex virus type 1 (HSV-1) causes reactivation of the virus. Previous studies have suggested that either latency-associated transcripts (LATs) were removed as an early consequence of reactivation or, alternatively, there was a population of latently infected cells which did not contain LATs. We have now attempted to detect this population of neurons by inserting a reporter gene (Escherichia coli lacZ gene), under the control of promoters other than LAT, into the HSV-1 strain 17 mutant in 1814, which was used in the earlier studies. One of these promoters, the human cytomegalovirus enhancer, resulted in weak expression of beta-galactosidase in DRG neurons for at least 5 months. The pattern of staining was predominantly homogeneous in neurons at 3 or 5 days post-infection or at 3 days post-explanation, and was predominantly speckled in latently infected neurons (1 to 5 months post-infection). About 30% of the beta-galactosidase-positive neurons did not contain LATs by in situ hybridization. However, the detergents used to enable penetration of the substrate for beta-galactosidase had also reduced the levels of the LATs; in neurons which originally had only small numbers of LATs this may have reduced levels to below those detectable by the methods used. There was, therefore, no unequivocal evidence for a population of latently HSV-1-infected cells which did not express LATs.

Animals↗
PubMed1995

A new breakthrough in treatment of visceral leishmaniasis in children.

Fifty cases of visceral leishmaniasis were admitted in Children's Hospital, Islamabad. Common clinical features were fever (100%), splenomegaly (100%), hepatomegaly (100%), anaemia (96%), abdominal distension (40%), bronchopneumonia (26%) and bleeding diathesis (22%). Hb was below 7.0 G/dl in 80%, white cell count below 4 x 10(9)/cmm in 88% and platelet count below 100 x 10(9)/c4mm in 86%. All the patients showed leishmania donovani bodies in the marrow smears. Fourteen patients were treated with aminosidine (15 mg/kg), intramuscularly daily for 4 weeks. All responded dramatically and none of them went into relapse in a year's follow-up. No side-effects were observed. Aminosidine can therefore, be recommended as a treatment of choice for visceral leishmaniasis in children.

Anemia↗
PubMed1995

Visceral leishmaniasis--a study of 38 cases on the basis of geographical distribution.

Geographical distribution of thirty-eight cases of visceral leishmaniasis (VL), who were diagnosed in the department of Pathology, Rawalpindi Medical College and two private laboratories in Rawalpindi and Islamabad is presented. Majority (84.2%) came from Azad Kashmir, especially from areas around Poonch (e.g., Rawlakot-28.9%; Bagh-23.7%; Dirkot-5.3% and Pallandari-2.6%) and areas around Muzaffarabad (e.g., Chakothi-13.2% and Punja Sharif-5.3%). Only two patients (5.3%) belonged to Gilgit agency. Four cases came from villages around Murree, Rawalpindi and Abbottabad. These places are not known as endemic areas of VL. It is proposed that epidemiological studies for VL should be carried out in areas of Azad Kashmir, especially concentrating on the places from where patients keep on presenting for treatment in various hospitals of Rawalpindi and Islamabad.

Adolescent↗
PubMed1995

The pattern of bone marrow infiltration in non-Hodgkin's lymphomas.

The pattern of bone marrow infiltration in 40 consecutive cases of non-Hodgkin's lymphomas (NHLs) having marrow involvement is presented. For histological break-up, working formulation of NHLs was used. Low grade NHLs (50%) were the commonest, followed by intermediate (32.5%) and high grade NHLs (17.5%), respectively. Histologically, small lymphocytic type (32.5%) was the commonest, followed by diffuse small cleaved cell (15%) type; follicle small cleaved cell, diffuse mixed small and large cell as well as lymphoblastic types were equally frequent (12.5% each). Other histological types were less common. The pattern of infiltration of the bone marrow was diffuse in 76.7% of intermediate, 70% of low and 100% of high grade NHLs. It was focal random (non-paratrabecular) in 15% of low grade and 15.4% of intermediate grade NHLs. Focal paratrabecular pattern was evident in 15% of low grade and 7.7% of intermediate grade NHLs.

Adolescent↗
PubMed1994

Reactivation of latent herpes simplex virus from explanted dorsal root ganglia.

Reactivation was induced by explantation of dorsal root ganglia (DRG) from mice that were latently infected with herpes simplex virus type 1. Reactivation was first detected, using combined in situ hybridization and immunocytochemistry, at 2 or 3 days post-explantation (p.e.). Evidence of reactivation was found primarily in neurons that did not also contain latency-associated transcripts (LATs). Occasionally, mRNA of immediate early gene 2 (IE2) or IE4/5, in the absence of other viral mRNAs or antigen, was found in LAT+ neurons. Thus, if reactivation was occurring in LAT+ neurons, the LATs must have been lost as an early consequence; however we could detect neither a decrease in the percentages of LAT+ neurons nor a reduction in the intensity of the LAT signal during the period of reactivation. However, the number of foci of reactivation was generally less than 2.9% of the estimated number of LAT+ cells in the DRG; this may account for our failure to see such changes. A redistribution of the LATs into the cytoplasm was found in some cells but this could reflect the poor survival and consequent death of the explanted neurons. We conclude that the majority of LAT+ neurons did not reactivate on explantation and that if reactivation occurred only in LAT+ neurons, the LATs must have been removed from the nucleus as an early consequence of reactivation. Alternatively, there may be a population of latently infected cells that do not express LATs.

Animals↗
PubMed1994

The increasing importance of vitamin B12 deficiency as a contributing factor to anemia in Malaysia.

A comparative study was done to determine the profile of vitamin B12 and folate status in Malaysians during two different periods. For the period of 1987/88, we analysed a total of 9,162 cases (inpatients) referred for vitamin B12 estimation and 10,290 cases for folate estimation. We found that 2.6% were vitamin B12 deficient and 31.2% were folate deficient. For the period of 1992/93, of the 9,962 cases assayed, 8.2% were found to be vitamin B12 deficient whereas 7.6% of the 10,355 cases referred were folate deficient. Vitamin B12 and folate were assayed either using microbiological or radioassays. These findings indicate that there appears to be a change in the status of both vitamin B12 and folate over the five year interval.

Anemia↗
PubMed1994

Severe aplastic anaemia--an aetiological correlation.

Over 4 years, 43 cases of severe aplastic anaemia (SAA) were seen. Etiologically 58.1% had idiopathic, 39.5% secondary and 2.3% congenital aplastic, anaemia. Idiopathic SAA was more common in patients between 0-15 years of age, whereas secondary SAA was more frequent in 16-60 years age group. Males were more commonly affected with a male:female ratio of 3.3:1. Amongst 17 cases of secondary SAA, chloramphenicol was responsible for 4, septran for 3, insecticides for 2 and anti-scabitic drugs, anti-diabetic drugs and "kushta from hakeem" in one patient each. Hepatitis associated SAA was suspected in 3 cases.

Adolescent↗
PubMed1994

A morphological pattern of 234 cases of leukemias.

Morphological pattern of 234 consecutive cases of various types of leukemias is presented. Acute leukemias (62.8%) were commoner than chronic (37.2%). Amongst acute leukemias, myeloid leukemias (AML) were more frequent as compared to lymphoblastic (ALL). AML:ALL ratio was 2.57:1 in adults and 1:3 in children. Amongst AML cases, M4 was the commonest, followed by M2, M1, M3 and M4 and M6 and M7 respectively. In ALL patients, L1 was the commonest, followed by L2 and L3 respectively. Amongst chronic leukemias, myelocytic leukemia (CML) was more common than lymphocytic leukemia (CLL) with a CML:CLL ratio of 3.1:1. In a total of 60 CML cases, two had juvenile CML, four were between 10 and 15 years of age and the remaining 54 were adults. Hairy cell leukemia (2 cases) and lymphoma/leukemia syndrome (5 cases) were uncommon.

Acute Disease↗
PubMed1993

Neurons containing latency-associated transcripts are numerous and widespread in dorsal root ganglia following footpad inoculation of mice with herpes simplex virus type 1 mutant in1814.

The herpes simplex virus type 1 (HSV-1) mutant in1814 lacks the ability to trans-activate immediate early gene transcription and enter lytic replication but it can establish and reactivate from latency. We therefore investigated the number of neurons that expressed latency-associated transcripts (LATs) in animals latently infected with in1814, the rescued revertant (1814R), or wild-type (wt) HSV-1. The percentage of LAT+ neurons increased with increasing doses of each of the viruses. After inoculation of equal amounts of infectious virus many more LAT+ neurons were observed in animals infected with in1814 than with 1814R or wt HSV-1. Whereas the LAT+ neurons in animals infected with 1814R or wt HSV-1 were largely confined to lumbar dorsal root ganglia (DRG) L4/L5/L6 (those which innervate the lower leg), in animals infected with in1814 they were also present in DRG not directly involved with such innervation (thoracic 12 and 13, L1, L2 and L3). We concluded that the large number of LAT+ neurons observed with in1814 was related to the high particle numbers in the inoculum and that spread of virus was related to limited replication as well as to the low neurovirulence of in1814. This spread was not unique to in1814 but when it occurred with more virulent viruses such as 1814R or wt HSV-1, it resulted in the death of the host.

Animals↗
PubMed1993

Reactivation in vivo and in vitro of herpes simplex virus from mouse dorsal root ganglia which contain different levels of latency-associated transcripts.

In the dorsal root ganglia (DRG) of mice latently infected with the herpes simplex virus type 1 mutant in1814, there are more neurons that contain latency-associated transcripts (LATs) than in DRG of mice infected with a dose of equal infectivity of either a revertant or a wild-type virus. We investigated whether higher levels of LAT+ neurons resulted in more extensive reactivation either in vivo following neurectomy of the sciatic nerve or in vitro after explantation into culture. Neurectomy appeared to induce expression of immediate early 1 mRNA (IE1mRNA) in neurons of mice latently infected with each of three viruses. However IE1mRNA was detected in no more than 0.25% of the neurons of DRG from animals 2 to 4 days after neurectomy, irrespective of the percentage of LAT+ neurons present. Of the 22 neurons shown to express IE1mRNA, none expressed LATs also. However the lack of expression of viral antigen and the absence of a reduced potential for reactivation on explanation suggested that neurectomy had not induced full reactivation involving lytic replication leading to the death of the latently infected neurons. When DRG were explanted into culture, the distribution of the frequency of reactivation was similar to the distribution of DRG that contained LAT+ neurons. The presence of a high proportion of LAT+ neurons was not directly associated with earlier detection of reactivation but such experiments cannot be regarded as quantitative. We therefore concluded that neurectomy did not result in a reduced reactivation potential as described by others and that the frequency of expression of IE1mRNA following neurectomy did not correlate with the number of LAT+ neurons present.

Animals↗
PubMed1993

Regional cerebral blood flow in chronic stroke patients.

BACKGROUND AND PURPOSE: The aim of this study was to investigate regional cerebral blood flow parameters during the postacute phase of unilateral ischemic stroke and to correlate them with clinical data. METHODS: Regional cerebral blood flow was measured in 187 patients in the stabilized phase of stroke by the xenon-133 inhalation method with 32 extracranial detectors. Thirty-eight patients were reexamined after a mean +/- SD time of 32 +/- 21.4 months. RESULTS: The overall detection of hypoperfusion was 92.0%, with asymmetries as the most sensitive index, especially for patients with a lesser degree of neurological disability. Neurological disability score was strongly associated with regional cerebral blood flow in the affected hemisphere (p < 0.0001) and with asymmetries (p < 0.0001). The presence of carotid obstruction further decreased the regional cerebral blood flow in the affected hemisphere and significantly increased asymmetry (p < 0.0001). Subjects who had no hypoperfusion at absolute values analysis were more frequently free of carotid disease and had less severe disability than those who had bilateral or unilateral regional absolute cerebral blood flow reduction. In 38 patients without new cerebrovascular events, a significant (p = 0.005) reduction of hemispheric regional cerebral blood flow asymmetries was found on a follow-up examination. CONCLUSIONS: These data confirm the value of regional cerebral blood flow asymmetries in stroke detection and point out that important clinical information is also contained in absolute values analysis.

Adolescent↗
PubMed1993

Regional cerebral blood flow and cerebrovascular reactivity in IDDM.

OBJECTIVE: To investigate both rCBF and cerebrovascular reactivity, evaluated as pre- and post-ACZ rCBF differences in a group of IDDM patients with differences in duration of disease and severity of complications. RESEARCH DESIGN AND METHODS: rCBF was measured by the 133Xenon inhalation method in 20 IDDM patients and in 15 healthy control subjects before and after an intravenous injection of ACZ, a carbonic anhydrase inhibitor commonly used to assess cerebrovascular reactivity. RESULTS: Basal global CBF (the mean of 32 regional values) was within the normal range in all patients but 1, who showed slight hyperperfusion; moreover, in 3 patients with long-lasting disease, some hypoperfused regions were found. ANOVA showed an inverse correlation between basal global CBF (P < 0.01) and duration of diabetes, but no correlation with Hb, MABP, serum glucose concentration, or GHb. Compared with control subjects, the percentage of global CBF increment after ACZ administration was significantly impaired in 4 patients and gave a borderline response in 2 patients; 4 of these poor ACZ responders had retinopathy, and 1 had suffered from a TIA. Duration of diabetes, Hb, MABP, serum glucose concentration, and GHb did not correlate with the percentage of post-ACZ global CBF changes, and did not differ among the 6 poor ACZ responders and the other diabetic patients or control subjects. CONCLUSIONS: These results confirm that global CBF is within the normal range in most IDDM patients, although it is significantly influenced by the duration of diabetes; pathophysiological correlates of the altered cerebrovascular reactivity need to be further investigated. rCBF measurements, before and after ACZ administration, seem to represent a safe and reliable tool for assessing cerebrovascular function in IDDM.

Acetazolamide↗
PubMed1993

Acute myeloid leukemia-FAB classification and its correlation with clinico-haematological features.

The French-American and British (FAB) classification of 62 consecutive cases of acute myeloid leukemia was undertaken. AML-M2 was the commonest FAB type (32.26%), followed by M1 and M4 (22.58% each), M5 (8.6%) and M6 and M7 (1.61% each), respectively. One of the patients was diagnosed as AML-MO (not a FAB type). The mean age of M1, M2, M3 and M5 cases was between 25 and 29 years, whereas in M4 patients it was 45.6 years. AML-M2, M4 and M5 were commoner in males, M1 in females and M3 equal in both sexes. Feeling of weakness, easy fatiguability and pallor were invariably present in all FAB types. All the patients of M1 and M5, 85% of M2, 64% of M4 and 50% of M3 presented with fever. Bleeding manifestations were most frequent in M3 cases followed by M5, M1, M4 and M2, respectively. Hepatomegaly and splenomegaly were relatively less prominent features in M3 as compared to other FAB types. Amongst the haematological parameters, anaemia was more severe in M1, leucocytosis in M2 and thrombocytopenia in M3 cases as compared to other FAB types.

Acute Disease↗