Search PubMed⌕ Search

Biomedical subjects

M Rahman

Publications and source records attributed to M Rahman.

At least 127 records · Page 7Linked to original sources
PubMed1998

Diabetes mellitus associated with arsenic exposure in Bangladesh.

The objective of this study was to assess whether arsenic exposure is a risk factor for diabetes mellitus as indicated in a few earlier studies. Arsenic in drinking water is known to occur in western Bangladesh, and in 1996, two of the authors conducted a survey of the prevalence of diabetes mellitus among 163 subjects with keratosis taken as exposed to arsenic and 854 unexposed individuals. Diabetes mellitus was determined by history of symptoms, previously diagnosed diabetes, glucosuria, and blood sugar level after glucose intake. The crude prevalence ratio for diabetes mellitus among keratotic subjects exposed to arsenic was 4.4 (95% confidence interval 2.5-7.7) and increased to 5.2 (95% confidence interval 2.5-10.5) after adjustment for age, sex, and body mass index. On the basis of a few earlier measurements of arsenic concentrations in drinking water by the authorities in Bangladesh and another 20 new ad hoc analyses, approximate time-weighted exposure levels to arsenic in drinking water could be estimated for each subject. Three time-weighted average exposure categories were created, i.e., less than 0.5, 0.5-1.0, and more than 1.0 mg/liter. For the unexposed subjects, the corresponding prevalence ratios were 1.0, 2.6, 3.9, and 8.8, representing a significant trend in risk (p < 0.001). The result corroborates earlier studies and suggests that arsenic exposure is a risk factor for diabetes mellitus.

Adult↗
PubMed1998

IMPALA: a simple restraint field to simulate the biological membrane in molecular structure studies.

The lipid bilayer is crucial for the folding of integral membrane proteins. This article presents an empirical method to account for water-lipid interfaces in the insertion of molecules interacting with bilayers. The interactions between the molecule and the bilayer are described by restraint functions designed to mimic the membrane effect. These functions are calculated for each atom and are proportional to the accessible surface of the latter. The membrane is described as a continuous medium whose properties are varying along the axis perpendicular to the bilayer plane. The insertion is analyzed by a Monte Carlo procedure applied to the restraint functions. The method was successfully applied to small alpha peptides of known configurations. It provides insights of the behaviors of the peptide dynamics that cannot be obtained with statistical approaches (e.g., hydropathy analysis).

Algorithms↗
PubMed1998

Monoclonal antibodies to the epitope alpha-Gal-(1-4)-beta-Gal-(1- of Moraxella catarrhalis LPS react with a similar epitope in type IV pili of Neisseria meningitidis.

Murine monoclonal antibodies (MAbs) against the A, B and C LPS serotypes of M. catarrhalis were generated and their binding specificity was examined in an enzyme-linked immunosorbent assay (ELISA). Two broadly cross-reactive monoclonal antibodies (MCA1 and MCC2) against the outer core region of LPS were further characterized. A panel of synthetic glycoproteins and glycolipids was used to determine the binding specificity of the MAbs. MCA1 and MCC2 bound specifically to alpha-Gal-(1-4)-beta-Gal of galabiose and globotriose glycoconjugates. The reactivity of the MAbs with galabiose was higher than that with globotriose. The MAbs could recognize the alpha-Gal-(1-4)-beta-Gal epitope only when it was in a terminal position. MCA1 was further shown to react with a similar epitope in the glycosylated type IV pili of N. meningitidis, which has been shown to contain a 1-4 linked digalactose at the terminal part of the saccharide present in the pili. MCA1 could efficiently recognize this epitope indicating that it was exposed on the surface of the pili.

Animals↗
PubMed1998

Prevention of cardiovascular disease in hypertensive patients with normal renal function.

Hypertension is an important risk factor for cardiovascular disease (CVD) in patients with normal renal function. After reviewing over two decades of clinical trial data and an even longer history of epidemiologic data, multiple consensus panels worldwide have made recommendations for the aggressive treatment of hypertension using both lifestyle modification and drug therapy. These data and recommendations provide the basis of the recommendations for preventing CVD in patients with renal disease. Most patients should have elevated blood pressure (BP) lowered to less than 140 mm Hg systolic and less than 90 mm Hg diastolic. Earlier and more aggressive intervention is recommended in high-risk hypertensive patients with risk factors (especially diabetes mellitus) or evidence of target organ damage or clinical CVD. Lifestyle changes are indicated as either initial therapy or concomitant therapy in all hypertensive patients to lower BP and to normalize other CVD risk factors. There is general agreement that clinical outcome data from controlled clinical trials should guide the selection of antihypertensive agents. Currently, these data are only available for thiazide diuretics and beta-blockers for most hypertensive patients with normal renal function and for the dihydropyridine calcium channel blockers in older hypertensive patients with isolated systolic hypertension. However, data may support the use of other agents in hypertensives with selected comorbidity (eg, ACE inhibitors in heart failure, beta-blockers after myocardial infarction, and so forth). However, with only 25% of hypertensive patients controlled to less than 140/90 mm Hg, achieving blood pressure control remains the most important goal in managing hypertension in this population.

Antihypertensive Agents↗
PubMed1998

Increasing frequency of mecillinam-resistant shigella isolates in urban Dhaka and rural Matlab, Bangladesh: a 6 year observation.

A total of 14,915 shigella isolates obtained in 1991-1996 from patients attending the Dhaka (urban) and Matlab (rural) treatment centres of the International Centre for Diarrhoeal Disease Research, Bangladesh were examined for susceptibility to ampicillin, co-trimoxazole, nalidixic acid, mecillinam and ciprofloxacin by a disc diffusion method. There were no ciprofloxacin-resistant shigella isolates. The prevalence of resistance to ampicillin, co-trimoxazole and nalldixic acid varied between isolates. It increased to similar degrees in isolates from both Matlab and Dhaka. However, resistance to mecillinam was more prevalent among isolates from Matlab than from Dhaka. The increase in mecillinam-resistant shigellae in the community may have grave implications for the empirical treatment of shigellosis in Bangladesh and other developing countries.

Amdinocillin↗
PubMed1998

Expression of apolipoprotein(a) kringle IV type 9 in Escherichia coli: demonstration of a specific interaction between kringle IV type 9 and apolipoproteinB-100.

A number of studies have provided evidence that lipoprotein(a) [Lp(a)] assembly is a two-step process in which initial non-covalent interactions between apolipoprotein(a) [apo(a)] and apolipoproteinB-100 (apoB-100) precede specific disulfide bond formation. We have designed a construct encoding apo(a) kringle IV type 9 (KIV9) in which the unpaired cysteine at position 67 in this kringle is replaced with a tyrosine. The single kringle was expressed in bacteria and purified to homogeneity from cell homogenates. The purified derivative (designated KIV9deltaCys) was assessed for its ability to bind to purified human LDL. This interaction was detected either by ELISA using immobilized LDL or by column chromatography in which LDL binding to KIV9deltaCys immobilized on Ni2+-Sepharose was determined. In both cases, the interaction of KIV9deltaCys and LDL was observed. Further, we demonstrated that the binding interaction was sensitive to the addition of amino acids including lysine, the lysine analogue epsilon-aminocaproic acid, arginine, phenylalanine and proline, with arginine and lysine having the greatest inhibitory effect. Binding of KIV9deltaCys to an immobilized apoB peptide spanning residues 3732-3745 of apoB was also demonstrated by ELISA. As was the case for LDL, this binding interaction was sensitive to the addition of arginine and lysine. Computer modeling of KIV9 demonstrated an excellent fit with residues 3732-3738 (PSCKLDF) of the apoB peptide. The modeling predicts the presence of overlapping lysine and phenylalanine-binding pockets in KIV9 which explains the inhibitory effects of lysine, arginine and phenylalanine which were observed in the binding assays. In summary, this study represents the first demonstration that KIV9 can interact directly with LDL through non-covalent interactions which may contribute to the first step of Lp(a) formation.

Amino Acid Sequence↗
PubMed1998

Rates of, and the factors affecting, cycle helmet use among secondary schoolchildren in East Sussex and Kent.

OBJECTIVES: To assess the level of cycle helmet wearing among young people in two counties in the South East of England in 1994, and to identify the factors associated with helmet wearing. DESIGN: Cross sectional survey in a convenience sample. SETTING: Secondary schools in East Sussex and Kent. SUBJECTS: Students in year 7 (aged 10-12 years) and year 11 (aged 14-16 years). Main outcome measures--Self reported "always wears a helmet". RESULTS: Among those who ride a bicycle, 32% of boys and 29% of girls aged 10-12 years, and 14% of boys and 10% of girls aged 14-16, reported that they always wear helmets. The variables that were most consistently associated with helmet wearing (that is significantly associated with helmet wearing in at least five of the six age, sex, and county subgroups) were: "parental encouragement to wear a helmet" "closest friend wears a helmet", "belief that laws that make children wear helmets are good", and "sometimes rides off-road". CONCLUSIONS: The self reported rates of always wearing a cycle helmet in East Sussex and Kent are consistent with overseas findings for populations who had not been exposed to intensive helmet promotion. The evidence suggests that parental encouragement has a favourable effect on rates of cycle helmet use among secondary schoolchildren, which is separate from and additional to peer influences. When designing a helmet promotion programme, therefore, it will have added impact if both parents and children are addressed.

Adolescent↗
PubMed1998

Cost-effectiveness analysis of partner notification program for human immunodeficiency virus infection in Japan.

Successful implementation of partner notification program (PNP) as a part of human immunodeficiency virus (HIV) prevention strategies in some developed countries motivated the execution of cost-effectiveness analysis of this program in Japan. Total number of HIV infected individuals and best estimated number of their partners in 1995 were used to elicit incremental cost-effectiveness ratio over no partner notification program. Index cases and their HIV positive partners world change their sex practice to safer one, thus preventing HIV transmission at a certain rate. This was translated to prevention of certain number of new HIV carriers and finally life years gained were calculated for it. The incremental cost-effectiveness ratio was US$ 4,930 per life year gained. Sensitivity analysis indicated that partner notification program was cost-effective over a wide range of assumptions. These results compare favorably with other medical interventions in Japan. In conclusion, the results of this analysis strongly support the implementation of partner notification program as a part of HIV prevention strategies in Japan.

Adult↗
PubMed1998

Knowledge and practices about HIV/AIDS among the commercial sex workers in Bangladesh.

A survey on knowledge and practices of 228 Bangladeshi commercial sex workers (CSWs) concerning AIDS was conducted in the largest brothel in Narayangonj, 20 km from the capital Dhaka in September through December, 1993. Only 18% of the respondents heard about AIDS and 8% knew about its propensity to sexual transmission. AIDS was believed to be curable by 5% of the total respondents. None were regular condom users, but 8% said condom use could prevent HIV infection. Vigorous AIDS awareness campaigns for the CSWs and their clients, leading to regular condom use, is necessary to prevent an explosive epidemic in Bangladesh.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Epidemiology of aplastic anaemia in the state of Sabah, Malaysia.

Aplastic anaemia is a rare disease which is more prevalent in the Far East. In Malaysia, it appears to be unusually common in the state of Sabah. A retrospective analysis of all cases of aplastic anaemia diagnosed between January 1993 and March 1996 was undertaken. The criteria of the International Aplastic Anaemia and Agranulocytosis Study (IAAAS) was used. In this 39 month period, 31 cases were confirmed by marrow trephine biopsy to be aplastic anaemia. The male-to-female ratio was 3.4. Median age of diagnosis was 23 years. There were 24 patients (77%) who were from the Kadazan-Dusun ethnic group, which forms 18% of the population of Sabah. The incidence of aplastic anaemia in Sabah appears to be higher than that reported elsewhere in the Far East, at 4.8 per million population per year. Peak incidence is in the elderly group at 8.6 per million followed by a second peak in young people aged 15 to 24 (7.9 per million). The aplastic anaemia to total acute leukaemia ratio is 0.37. The marked male preponderance and apparent susceptibility of the Kadazan-Dusun people are also notable. A further prospective study to address the true incidence of aplastic anaemia and possible aetiologic factors accounting for these observations is necessary.

Adolescent↗
PubMed1998

The effect of child mortality on fertility regulation in rural Bangladesh.

This study analyzes longitudinal data from Matlab, Bangladesh, to examine the impact of child mortality on subsequent contraceptive acceptance and continuation. The strong negative impact is found to attenuate with family size, indicating a "replacement effect". An "insurance effect" is observed as contraceptive acceptance and continuation were negatively associated with the number of previous deaths of children. Couples seem to find contraceptive use acceptable if the child who dies is one of a large family. Potentially, contraceptive use could be acceptable for spacing after a child in a small family dies. Family planning programs can help to reduce fertility and maternal and child health risks substantially by supplying appropriate methods to those couples who have experienced a young child's death; to be most effective, methods should be supplied immediately after the child's death.

Adult↗
PubMed1997

Pathophysiology and treatment implications of hypertension in the African-American population.

Regardless of the etiology, hypertension remains a major public health problem in African-Americans and is associated with significant morbidity and mortality. Additional data on the pathophysiology of this disease in this population are needed, as are data on the best therapies to decrease the high complication rate. Because many of the large studies on hypertension have included few African-Americans, recruitment of this ethnic group into clinical trials should be promoted. Further studies into the genetic factors in the pathophysiology of racial differences in hypertension may shed more light on this complex issue.

Antihypertensive Agents↗
PubMed1997

The role of the cytochrome P450-dependent metabolites of arachidonic acid in blood pressure regulation and renal function: a review.

Arachidonic acid metabolism through the cytochrome P450-dependent monooxygenase system has been the subject of considerable research interest over the last several years. This article reviews the biological actions of the metabolites generated through this pathway and explores their role in the regulation of renal function and systemic blood pressure. Arachidonic acid is metabolized by the cytochrome P450-dependent monooxygenase system in three ways: epoxidation, resulting in the formation of 5,6-, 8,9-, 11,12-, 14,15-epoxyeicosatrienoic acids; allylic oxidation, resulting in the formation of 5,8,9,11,12,15-hydroxyeicosatetraenoic acids (HETE); and hydroxylation, resulting in the formation of 19,20-HETEs and 20-carboxyl arachidonic acid. Elements of this pathway have been localized in the kidney and several extrarenal sites. Vasodilation, vasoconstriction, inhibition of Na+,K+-ATPase, inhibition of ion transport and modulation of cell growth have been some of the diverse physiological actions demonstrated by metabolites produced by this pathway. As a physiological correlate of these properties, considerable evidence has accumulated regarding the role of the cytochrome P450-dependent metabolites of arachidonic acid in the pathogenesis of hypertension in the spontaneously hypertensive rat. Data in humans are limited, but in small studies increased production of these metabolites has been shown in hypertensive persons. In summary, several properties of products of this "third" pathway of arachidonic acid metabolism suggest a role in cardiovascular and renal function. Additional studies are needed to precisely define the role of this pathway in human hypertension.

Animals↗
PubMed1997

PilC of pathogenic Neisseria is associated with the bacterial cell surface.

Adherence of pathogenic Neisseria to target host cells is mediated by pili. PilC1 and PilC2 are two high-molecular-weight proteins involved in pilus assembly and cellular adherence functions of the pili. Inactivation of pilC1 or pilC2 in N. meningitidis resulted in clones that expressed the same number of pili as the parent, contained no alterations in pilE and showed no detectable differences in PilE glycosylation. However, the PilC2+ pilC1- mutant showed much reduced adherence to target cells, indicating that production of PilC1 is essential for pilus-mediated adherence. To study further the functional differences between the meningococcal pilC genes, we determined the complete nucleotide sequence of pilC1 and pilC2 of N. meningitidis. Alignment of six PilC sequences demonstrated that PilC is composed of both conserved and variable regions. By immunogold labelling of bacterial sections we showed that PilC is present in the membranes of both piliated and non-piliated bacteria. Further, we demonstrated that PilC is associated with the bacterial cell surface.

Amino Acid Sequence↗