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Biomedical subjects

S Iqbal

Publications and source records attributed to S Iqbal.

At least 19 recordsLinked to original sources
PubMed1998

A two-color BCR-ABL probe that greatly reduces the false positive and false negative rates for fluorescence in situ hybridization in chronic myeloid leukemia.

The t(9;22) translocation resulting in the fusion of BCR and ABL genes is pathognomonic in chronic myeloid leukemia (CML) and may be investigated at the molecular level using fluorescence in situ hybridization (FISH). Two-color BCR-ABL probes visualizing one fusion signal (1F FISH) have high false positive rates (FPR) and false negative rates (FNR). The FPR is a result of the random spatial association of probe signals within normal interphase cells so that some cells appear to contain the BCR-ABL fusion gene. The FNR of 1F FISH probes depends on the distance between the BCR and ABL probes hybridized to the BCR-ABL fusion gene (< or =368 kb); the "gap" between the signals causing the cell to be interpreted as normal. To overcome these difficulties, a two-color probe was used, employing four yeast artificial chromosome (YAC) sequences that span the breakpoint regions of the BCR and ABL genes and that visualize the two fusion signals BCR-ABL and ABL-BCR in CML cells (2F FISH). The FNR for the 2F FISH probes was assessed on clonal Ph+ granulocyte-macrophage-colony-forming cell (CFU-GM) derived colonies and was reduced to 0.4% (2/450), compared with an FNR of 13.5% (111/823) with 1F FISH. The FPR in normal mononuclear cells for the 2F FISH was 0. 19 +/- 0.12% (3/1,700), whereas the FPR using 1F FISH was 4.5 +/- 2.3% (63/1,294). The 2F FISH can thus be used to evaluate very small frequencies of BCR-ABL-positive and -negative interphase cells and may be of use in the clinical monitoring of CML.

Adult↗
PubMed1997

Efficiency of the polymerase chain reaction amplification of the uid gene for detection of Escherichia coli in contaminated water.

Direct detection of Escherichia coli from polluted river water was achieved using polymerase chain reaction (PCR) amplification of the uid gene. Amplification using DNA from environmental samples resulted in non-specific DNA fragments. Specific amplification was achieved through use of the touch-down PCR procedure. Targeting the uidA structural region of the gene gave reproducibly better amplification than targeting the uidR regulatory region. The data demonstrate conditions for optimal specific detection.

Bacteriological Techniques↗
PubMed1997

Prevalence and severity of viral hepatitis in Pakistani pregnant women: a five year hospital based study.

A hospital based observational study was carried out on pregnant women presenting with either acute hepatitis or fulminant hepatic failure (FHF), during the past years. Of 53 patients, 20 (38%) developed FHF.Non-A, Non-B was the commonest cause (62%) followed by hepatitis B in 17% and hepatitis A in 4% cases. Eight women expired (case fatality rate 15%) with a high maternal mortality (62%) caused by NANB hepatitis. Perinatal mortality was 30%. Poor prognostic factors identified were lack of antenatal care, severity of jaundice, history of somnolence, gastrointestinal bleeding and a high grade of encephalopathy.

Adult↗
PubMed1996

Analysis of a family containing three members with common variable immunodeficiency.

BACKGROUND: Common variable immunodeficiency (CVID), a diverse immunodeficiency syndrome characterized by low immune globulin levels and recurrent infections, has been observed in families with the HLA A1 B8 DR3 haplotype. METHODS: We report a two-generation family with three members affected by CVID. Immunoglobulin levels, antibody titers, lymphocyte marker analyses, T cell proliferation assays, and HLA typing were performed on the affected family members. RESULTS: Studies of the affected patients revealed low levels of immunoglobulin G and A; normal tetanus, rubella and rubeola antibody titers; low B cell numbers; normal T cell numbers; normal CD4/CD8 ratios and normal lymphocyte proliferation studies. HLA typing did not reveal the HLA A1 B8 DR3 haplotype previously associated with familial CVID. CONCLUSION: We report a family with a unique presentation of CVID involving possible genetic inheritance other than the HLA A1 B8 DR3 haplotype and possessing lymphocyte characteristics distinct from those usually seen in sporadic CVID.

Adolescent↗
PubMed1995

Enhanced biodegradation and emulsification of crude oil and hyperproduction of biosurfactants by a gamma ray-induced mutant of Pseudomonas aeruginosa.

A gamma ray-induced mutant of Pseudomonas aeruginosa strain S8, capable of hyperproduction of biosurfactant from hydrocarbons, was isolated and named as EBN-8. The mutant showed 3-4 times more hydrocarbon emulsification/conversion as compared to the parent when grown on Khaskheli crude oil in minimal medium. Enhanced biosurfactant production and hydrocarbon utilization by the mutant was also observed during growth on heptadecane in minimal medium as indicated by emulsion index and surface tension of cell-free culture broth. Using heptadecane as carbon and energy source, time course for the growth (cfu ml-1) and biosurfactant production were compared for both parent and mutant. These studies were carried out for 24 d at 30 +/- 2 degrees C and for 20 d at 37 degrees C. Growth of EBN-8 was much faster compared to the parent as well as being 2-3 times more hyperproductive.

Alkanes↗
PubMed1994

Intralesional corticosteroid therapy for childhood cutaneous hemangiomas.

Response to intralesional steroid therapy (triamcinolone acetonide and betamethasone acetate) was studied in 70 children of all ages with 74 cutaneous hemangiomas located in a variety of locations. One to seven injections were given without anesthesia with a mean interval of 6 weeks between the injections. Results analyzed 2 months after the last injection showed more than 75% reduction in volume in 43 (58.11%), 50% to 75% reduction in 16 (21.62%), 25% to 50% reduction in 9 (12.16%), and less than 25% reduction in 6 (8.11%) lesions. Response was not related to age, sex, or site of the lesion, but only 2 lesions (22.22%) with an initial volume of more than 20 cm3 showed more than 50% reduction. None showed regrowth within a mean follow-up period of 14 months. Transient cushingoid faces and hypopigmentation were noted in 2 patients each. We feel that intralesional steroid therapy is safe and effective for all cutaneous hemangiomas irrespective of site, sex, or age of the patient.

Betamethasone↗
PubMed1993

SK&F 97426-A a more potent bile acid sequestrant and hypocholesterolaemic agent than cholestyramine in the hamster.

SK&F 97426-A is a novel bile acid sequestrant which was selected for comparison with cholestyramine in vivo because of its superior in vitro bile acid binding properties. The effects of the two sequestrants on faecal bile acid excretion, plasma total cholesterol, VLDL + LDL and HDL cholesterol and triglyceride concentrations and on liver enzymes involved in the synthesis and metabolism of cholesterol were investigated in normocholesterolaemic hamsters. Four studies were conducted to determine the relative potencies of the two resins using a range of doses of the sequestrants over treatment periods of up to 2 weeks. Curves fitted to the resulting data allowed common maximum responses and separate ED50s to be calculated for each sequestrant. The maximum response of both sequestrants was to increase bile acid excretion by 352% and lower plasma total cholesterol by 37-58%. LDL + VLDL and HDL cholesterol were reduced by 56-75% and 25-41%, respectively. SK&F 97426-A was 3 times more potent than cholestyramine at increasing the excretion of bile acids in the faeces and 2.1-3.4-fold and 2.3-3.2-fold more potent at lowering total plasma cholesterol and LDL plus VLDL cholesterol, respectively. In some of the experiments SK&F 97426-A was also more potent than cholestyramine at lowering HDL cholesterol. Plasma triglycerides were also lowered by both sequestrants by up to 31% after 1 week but the relative potency could not be determined. These HDL cholesterol and total triglyceride lowering effects of bile acid sequestrants in the hamster are known not to occur in people treated with cholestyramine. There were minimal differences between hamsters treated for 1 or 2 weeks in the relative potencies or ED50s calculated for the total plasma cholesterol, LDL + VLDL and HDL cholesterol. Both sequestrants may have been slightly more efficacious on these parameters after 2 weeks of treatment. Liver weights were reduced by about 15% by both sequestrants at 2% (w/w) in the diet for 1 week. The activities of the liver HMG-CoA reductase and cholesterol 7 alpha-hydroxylase were increased as expected, whilst the activity of the acyl-CoA:cholesterol acyltransferase was reduced by both sequestrants at this dose. SK&F 97426-A was, therefore, 2-3-fold more potent as a bile acid sequestrant and hypocholesterolaemic agent than cholestyramine when tested in the hamster.

Animals↗
PubMed1991

Maintenance of mixed-function oxidase and conjugation enzyme activities in hepatocyte cultures prepared from normal and diseased human liver.

Isolated hepatocytes were prepared from normal and diseased human livers and maintained in primary monolayer culture for up to 96 h. The viability and yields of cell preparations obtained from diseased livers did not differ significantly from those obtained from normal livers. During the culture period a significant increase in cell protein/DNA ratio was observed in both normal and diseased hepatocytes. The maintenance of a number of drug metabolising enzyme activities was determined in these hepatocytes during 96 h of culture. In normal hepatocytes the maintenance pattern of mixed-function oxidase activities (ethoxycoumarin-O-deethylase and ethoxyresorufin-O-deethylase) was clearly different from that of the conjugating enzymes (sulfotransferase and glutathione transferase). Whereas ethoxycoumarin-O-deethylase and ethoxyresorufin-O-deethylase activities declined sharply over the first 24 h in culture and then either totally or partially recovered, sulfotransferase and glutathione transferase activities were found to be relatively more stable initially but thereafter decline progressively. In diseased hepatocytes mixed-function oxidase activities were maintained less well than the corresponding activities in normal hepatocytes whereas conjugation enzyme activities were maintained to a similar extent.

Adolescent↗
PubMed1990

Drug metabolism in end-stage liver disease. In vitro activities of some phase I and phase II enzymes.

The activities of a number of drug metabolising enzymes were measured in liver samples obtained from three groups of subjects: normal donors, patients with primary biliary cirrhosis (PBC), and patients with other types of liver disease. In the latter group, all the enzyme activities determined were impaired relative to the normal group. In the PBC group, however, enzyme activities were altered more selectively. (a) Activities of the methyl cholanthrene-inducible forms of cytochrome P-450 were decreased compared to normal controls, whereas the activities of the phenobarbitone-inducible isozymes were relatively unaffected. (b) Sulfotransferase activities were decreased significantly compared to the normal group, whereas sulfatase activities remained unaltered.

Adolescent↗
PubMed1988

Ileal entrapment as a complication of fractured pelvis.

A case of entrapment of small bowel in a fracture of the pelvis is presented. It was found on laparotomy in the present case, but contrast enema or computerized tomography have been reported as diagnostic of this rare, life-threatening condition.

Adult↗
PubMed1987

Ileal absorption of tyrosine-conjugated bile acids in Wistar rats.

We recently reported that tyrosine-conjugated bile acids, when injected intravenously into bile-fistula rats, are extracted by the liver and secreted intact into bile with an efficiency similar to that seen for taurocholate. Now the effect of tyrosine and glycyltyrosine conjugation of bile acids on ileal absorption has been studied in Wistar rats. 125I-labelled tyrosine- and glycyltyrosine-conjugated bile acid or [14C]taurocholate was injected in 400 microliters aliquots of physiological saline buffered to pH 7.8 into the ileal lumen of bile-fistula rats. Recovery of bile salts in bile was taken as proof of ileal absorption. In comparison with taurocholate, ileal absorption was about 10% less for cholyltyrosine and chenodeoxycholyltyrosine and about 50% less for deoxycholyltyrosine. Thus, tyrosine-conjugated bile acids are absorbed by the ileum and excreted into bile and may undergo enterohepatic circulation. Low recoveries of deoxycholyltyrosine relative to deoxycholylglycine suggested that side chain structure was important for ileal absorption of 3 alpha,12 alpha-dihydroxy bile acids. Elongation of cholic acid to form cholylglycyltyrosine markedly reduced 90-min cumulative ileal absorption relative to cholyltyrosine. Although initial rates of recovery of cholylglycyltyrosine were comparable to those of the other bile acids, very little further absorption was seen in the last hour of the experiment, suggesting that this compound was rapidly degraded within the intestinal lumen.

Animals↗