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Biomedical subjects

M Iqbal

Publications and source records attributed to M Iqbal.

At least 127 records · Page 7Linked to original sources
PubMed1993

Cloning and expression of the bovine intestinal alkaline phosphatase gene: biochemical characterization of the recombinant enzyme.

A complete genomic clone and a full-length cDNA coding for bovine intestinal alkaline phosphatase have been isolated and sequenced. The gene (5.4 kb) contains 11 exons separated by ten small introns at positions identical to those other members of the eukaryotic tissue-specific alkaline phosphatase family. In addition, 1.5 kb of upstream sequences contain putative regulatory elements showing sequence similarity to human and mouse intestinal alkaline phosphatase promoter sequences. To achieve recombinant bovine intestinal alkaline phosphatase expression, the coding region of the gene was subcloned into the pcDNA I eukaryotic expression vector and transfected into Chinese hamster ovary cells. Recombinant bovine intestinal alkaline phosphatase displays enzymatic properties comparable with those of purified native bovine intestinal alkaline phosphatase, a slightly increased thermal stability and, upon desialylation, it shows a homogeneous behaviour in agarose gel electrophoresis and isoelectric focusing. The availability of the recombinant bovine intestinal alkaline phosphatase and the elucidation of its primary sequence will help to accelerate our efforts to obtain the first crystallographic model of a eukaryotic alkaline phosphatase molecule.

Alkaline Phosphatase↗
PubMed1992

Characterization of a prototype strain of hepatitis E virus.

A strain of hepatitis E virus (SAR-55) implicated in an epidemic of enterically transmitted non-A, non-B hepatitis, now called hepatitis E, was characterized extensively. Six cynomolgus monkeys (Macaca fascicularis) were infected with a strain of hepatitis E virus from Pakistan. Reverse transcription-polymerase chain reaction was used to determine the pattern of virus shedding in feces, bile, and serum relative to hepatitis and induction of specific antibodies. Virtually the entire genome of SAR-55 (7195 nucleotides) was sequenced. Comparison of the sequence of SAR-55 with that of a Burmese strain revealed a high level of homology except for one region encoding 100 amino acids of a putative nonstructural polyprotein. Identification of this region as hypervariable was obtained by partial sequencing of a third isolate of hepatitis E virus from Kirgizia.

Amino Acid Sequence↗
PubMed1992

Association of hepatitis E virus with an outbreak of hepatitis in Pakistan: serologic responses and pattern of virus excretion.

Hepatitis E virus (HEV), a positive-strand RNA agent, has been associated with enterically transmitted non-A, non-B hepatitis in Asia, Africa, and Mexico. To evaluate the role of HEV in an outbreak of hepatitis in Pakistan, we used immune electron microscopy to detect 1) antibody to HEV, for evidence of infection, and 2) virus, to determine the pattern of HEV excretion. Paired sera from 2 patients were assayed for antibody by using reference HEV: one seroconverted, an atypical finding for HEV infections; the other had high levels of anti-HEV in both sera. Virus particles with the size (29 x 31 nm) and morphology of HEV were detected in feces from 10 of 85 patients and serologically identified as HEV by using reference antibodies from an HEV-infected chimpanzee. One of these HEV-containing specimens was collected 9 days before the onset of jaundice; it was among feces from 38 outpatients with nonspecific symptoms and biochemical hepatitis, 12 of whom subsequently developed jaundice. The other 9 feces with HEV were among 36 collected within 7 days of the onset of acute icteric hepatitis; all 11 feces from days 8 to 15 were negative for HEV. Fecal concentrations of HEV appeared to be lower than those of many enteric viruses: only one specimen contained as many as 5 particles per EM grid square. It is concluded that HEV was etiologically associated with the epidemic and was predominantly excreted at very low levels during the first week of jaundice.

Antibodies, Viral↗
PubMed1992

Mothers' fear of child death due to acute diarrhoea: a study in urban and rural communities in northern Punjab, Pakistan.

The investigation of cultural models of diarrhoeal illness which are employed by mothers and their emotional responses to children's illnesses is presented in a study of 595 households in urban and rural communities in Punjab, Pakistan. The household survey of mothers of children 0-36 months was complemented with in-depth interviews of a subsample of 70 mothers. Findings indicate that diarrhoea must be regarded not only as a disease but as a symptom belonging to several popular illness categories. Mothers' emotional responses to symptoms are in part shaped by the illness categories to which they assign a child's diarrhoea episode, and maternal fears that symptoms of diarrhoea may be life threatening are associated with previous experiences with death of children, with treatment choices and help-seeking. A significantly higher proportion of mothers who fear diarrhoea to be life threatening to their children than mothers with other concerns choose to use NIMKOL, the Pakistan ORS. The necessity of recognizing the complexity of interpretive and emotional processes which shape the care of children and the home treatment of childhood disease is emphasized.

Attitude to Death↗
PubMed1992

Study of arterial aneurysms.

A review of 46 patients operated for arterial aneurysms over an eight years period is presented. Twenty-nine patients developed aneurysm following vascular trauma while 17 had atherosclerotic aneurysms. Thirty-one patients presented with painless swelling or swelling with mild pain and four patients with frank rupture. Reconstruction was successful in all cases with a peri-operative mortality of only 4.3%. Unlike western countries, trauma is the leading cause of aneurysm and aneurysms can be managed with minimal morbidity and mortality.

Adolescent↗
PubMed1991

An opioid pancreatic peptide produces ileal muscle inhibition and naloxone-reversible analgesia.

The opioid activity of immunoreactive beta-endorphin-like peptide extracted from pork pancreas duplicates the effects of morphine and synthetic beta-endorphin when measured by inhibition of isolated guinea pig ileal muscle response to electro-stimulation in vitro and by morphine-like analgesia following intravenous injection in the mouse. These responses are reversed by the opiate antagonist naloxone, indicating that a potent opioid mu receptor binding ligand is present in pancreatic extract. These findings imply a pancreatic source of plasma immunoreactive beta-endorphin that may explain a number of physiological and behavioral effects generally attributed to hypophyseal beta-endorphin alone.

Analgesics↗
PubMed1991

Feeding practices for young Pakistani children: usual diet and diet during diarrhoea.

Diarrhoea is among the foremost disorders responsible for high mortality and morbidity in children of third world countries. In addition, improper feeding during diarrhoea leads to a vicious cycle of frequent episodes of diarrhoea and malnutrition in these children. In this study 595 households (200 urban and 395 rural) with 741 children who met the age criteria of 36 months or less were randomly selected for assessing the feeding practices during diarrhoea. Out of these, 276 (37%) were infants and 465 (63%) were toddlers. The majority of both breastfed and non breastfed children were also receiving solids and liquid foods. Animal milk was used by 89% of non-breastfed children. Forty six percent of breastfed and 78% of non-breastfed children were given "Khitchri" (rice cooked with lentils) as a solid diet. During diarrhoeal episodes, most mothers (70%) continued breast feeding their children. Whereas, 53% children also received solid and semi-solid diet which was either "Khitchri" or banana as mentioned by more than half of the respondents. The majority of mothers (97%) considered breast-feeding to be a good practice during childhood diarrhoea.

Breast Feeding↗
PubMed1990

Comparative trial of low-dose, intradermal, recombinant- and plasma-derived hepatitis B vaccines.

The immunogenicity and reactogenicity of low-dose, recombinant DNA and plasma-derived hepatitis B vaccines were investigated in a prospective, double-blind, randomized, controlled trial. Volunteers (153) received either recombinant vaccine, 10 micrograms in 1 ml intramuscularly; plasma-derived vaccine, 2 micrograms in 0.1 ml intradermally or recombinant vaccine, 1 microgram in 0.1 ml intradermally at 0, 30, and 150 days. Peak geometric mean concentrations of antibody to hepatitis B surface antigen at day 200 were 1094, 387, and 43 mIU/ml, respectively. By day 360, these concentrations had fallen to 346, 124, and 19 mIU/ml, respectively (P less than .05 between groups both dates). Number of subjects with antibody greater than or equal to 10 mIU/ml at day 200 was similar between the 10-micrograms recombinant and 2-micrograms plasma-derived groups (94% vs. 90%), while only 78% of the 1-microgram recombinant group had protective concentrations of antibodies (P less than .05). Erythema and induration occurred in most subjects in both intradermal groups, while pain was prominent at the intramuscular site especially after the second dose. Thus, plasma-derived vaccine, 2 micrograms in 0.1 ml intradermally, appears to be an acceptable cost-saving method for hepatitis B immunization, while recombinant-derived vaccine, 1 microgram in 0.1 ml intradermally, produced less satisfactory results.

Adult↗
PubMed1990

The use of ORS (Nimkol) in management of childhood diarrhoea by mothers in the suburbs of Rawalpindi-Islamabad.

A total of 595 respondents (200 from urban Kachi-abadis and 395 from rural communities of Rawalpindi-Islamabad) were interviewed for their knowledge about the use of ORS (Nimkol) in childhood diarrhoea. Most of the respondents were mothers with low literacy rate (23%). The prevalence of current diarrhoea among children was 36.8% on the day of interview whereas 57% of the children had history of having suffered from an episode of diarrhoea during the past two weeks. About 75% respondents claimed that they had an experience of using ORS (Nimkol). Most of them (72.1%) had used ORS (Nimkol) for childhood diarrhoea and dehydration and 28% had used it for diseases other than childhood diarrhoea or on doctor's advice. Only 11% mothers of children who were currently suffering from diarrhoea were using ORS (Nimkol) and a few mothers mentioned of giving home made fluid remedies like salt-water, salt-sugar-water or lemon-sugar-salt water for childhood diarrhoea. The use of ORS (Nimkol) was more common among the families with higher income. Regarding the preparation of ORS (Nimkol) solution, 57.8% respondents had fairly accurate knowledge. Fifty percent of the respondents had procured ORS (Nimkol) from the hospitals or clinics.

Age Factors↗
PubMed1989

An outbreak of enterically transmitted non-A, non-B hepatitis in Pakistan.

An epidemic of enterically transmitted non-A, non-B hepatitis occurred at a college in Sargodha, Pakistan in early 1987. There were 133 clinical cases, an attack rate of approximately 20%. Though the disease was relatively mild, all clinical cases required hospitalization and prolonged convalescence. Nearly all cases were associated with a single water source. The epidemic ended when the water supply was improved. This is the 4th described epidemic of non-A, non-B hepatitis in Pakistan.

Acute Disease↗
PubMed1989

Prospective study of 111 cases of thyroid surgery for post-operative morbidity and mortality.

One hundred and eleven patients were operated for various types of goitre between December, 1985 to June, 1988. These were evaluated to assess the morbidity and mortality associated with thyroid operations. A mortality of 0.9% was noted, owing to advanced age and fatal laryngeal oedema. Recurrent laryngeal nerve damage was seen in one (0.90%) case. Transient Parathyroid insufficiency appeared in 8.10% cases while the permanent damage occurred in one (0.9%) case only. Wound complications, including haematoma formation were noted in 14.40% cases. This study indicates that the thyroid surgery can be performed with acceptable morbidity and mortality, under the prevailing circumstances.

Adolescent↗
PubMed1988

Implications of protein folding. Additivity schemes for volumes and compressibilities.

Partial specific volume and compressibility properties of the extended state of proteins are estimated from additivity schemes using revised amino acid and peptide data. These calculated properties are compared with the experimental data of the native state in order to assess the contribution from folding. Results of this treatment show that, in the case of partial specific volumes, there is close agreement between the two data sets for a number of proteins. The implication is that subtle compensatory contributions in volume occur during the folding process. In the case of compressibilities, however, a substantial difference is observed which is believed to arise because of the hydrophobic interior created in the native protein as a result of the folding process. Using suitable measures of protein hydrophobicities and estimates of the fraction of buried apolar residues, a "micellar model of protein compressibility" is proposed and tested for several proteins. Results obtained from this model show good agreement with the experimental data for the native state of a number of proteins.

Algorithms↗
PubMed1988

Field bioassays of permethrin-treated uniforms and a new extended duration repellent against mosquitoes in Pakistan.

Field bioassays were conducted to evaluate the effectiveness of different treatment combinations of permethrin-impregnated clothing and a new extended duration repellent formulation of deet against natural populations of mosquitoes in Islamabad, Pakistan. Tests were initiated 2-2 1/2 hours prior to sunset and volunteers who wore the topical repellent applied it 8 hours earlier. The most effective treatment was a combination of wearing both the permethrin-impregnated clothing and the repellent on exposed skin. This combination provided 100% protection from bites whereas volunteers wearing only treated clothing received 57% protection. Those wearing only repellent received 89% protection, but, under the biting pressure observed, this was not significantly different from the treated clothing-repellent combination.

Animals↗
PubMed1988

Effect of oxidation on the properties of apolipoproteins A-I and A-II.

Purified apolipoprotein A-I has been separated by reversed-phase high performance liquid chromatography (HPLC) into multiple peaks and these peaks have been characterized. One peak, apoA-Ib had a relatively longer retention time on HPLC but its retention time could be shortened by treatment by hydrogen peroxide. CNBr cleavage studies indicated that the differences in apoA-Ib and in its oxidation product, apoA-Ia, were due to the different oxidation states of methionine. This phenomenon was also observed in apoA-II, where methionine oxidation produced two more forms of this apolipoprotein in addition to the native form. These isomers were found to have different secondary structures and affinities for lipid. Model peptide analogs of the amphipathic helix with the same sequence but with methionine and methionine sulfoxide at the nonpolar face of the amphipathic helix were synthesized and studied. It was found that the lipid affinities of these synthetic peptide isomers were very different. They also differed in their secondary structures as studied by circular dichroism (CD). We propose that methionine oxidation introduces hydrophilic residues at the nonpolar face of the amphipathic helical domains of these apolipoproteins and, therefore, alters their secondary structure and lipid affinity.

Apolipoprotein A-I↗