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Biomedical subjects

M Rahman

Publications and source records attributed to M Rahman.

At least 19 recordsLinked to original sources

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

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

Antimicrobial resistance in organisms causing diarrheal disease.

Antimicrobial resistance is becoming increasingly important in the treatment of enteric infections, particularly those due to Shigella, Vibrio cholerae, enterotoxigenic Escherichia coli (associated with traveler's diarrhea), and Salmonella typhi. The rate of antimicrobial resistance is highest in the developing world, where the use of antimicrobial drugs is relatively unrestricted. Of greatest immediate concern is the need for an effective, inexpensive antimicrobial that can be used safely as treatment for small children with dysentery due to Shigella, primarily Shigella dysenteriae type 1.

Campylobacter jejuni

Human immunoglobulin isotype and IgG subclass response to different antigens of Moraxella catarrhalis.

Enzyme immunoassays were tested for the determination of antibodies of different isotypes and IgG subclasses to Moraxella catarrhalis in human sera. An assay based on an outer membrane protein preparation (OMP) as antigen was compared to assays using whole bacterial cells and a purified lipopolysaccharide preparation. There was a good correlation between the results obtained with the OMP preparation and the whole-cell antigen. In paired sera, optimal sensitivity was obtained by using the OMP preparation as coating antigen and testing for a rise in IgG3 antibodies. However, patients with high levels of antibodies in acute serum had no or only an insignificant antibody response during infection.

Adult

Phenotypic and genotypic changes in Vibrio cholerae O139 Bengal.

To find reasons for the recent decline of Vibrio cholerae O139 Bengal cholera in Bangladesh, phenotypic and genotypic changes in O139 isolates obtained from patients with cholera from 1993 to 1996 were studied. The isolates were tested for the presence of ctx and tcpA genes, hemagglutinin/protease (HA/P), capsule, D-mannose-sensitive hemagglutinin (MSHA), L-fucose-sensitive hemagglutinin (FSHA), tube test (tube) and CAMP test (CAMP) hemolytic activities, resistance to 2,4-diamino-6,7-diisopropyl pteridine (O/129) and trimethoprim-sulfamethoxazole (TMP-SMX), and genotype by pulsed-field gel electrophoresis (PFGE). All isolates possessed ctx and tcpA genes, HA/P, and a capsule. Most isolates were negative for FSHA, but although the majority of the isolates were positive for MSHA, no discernible trend in the activity was found during the study period. All early isolates were CAMP hemolysin positive and resistant to the vibriostatic compound O/129 and TMP-SMX, the two properties that could be used for the presumptive diagnosis of O139 cholera. However, subsequently, isolates that were CAMP hemolysin negative and susceptible to TMP-SMX and O/129 were increasingly encountered, with all the 1996 isolates being so, which suggested that these properties can no longer be used for the presumptive diagnosis of O139 cholera. V. cholerae O139 isolates that were CAMP hemolysin positive and resistant to O/129 and TMP-SMX produced a disease of greater severity than that caused by the CAMP hemolysin-negative and susceptible isolates on the basis of the lengths of stay of the hospitalized patients. The study period witnessed the evolution of four different genotypes by PFGE. All of these data suggested that the V. cholerae O139 isolates have undergone changes in some properties. However, how these changes influenced their prevalence relative to that of V. cholerae O1 in human infection is not clear. Studies of the environmental factors will provide the key for an understanding of the relative abundance of these vibrios.

Adult

Awareness of sexually transmitted disease among women and service providers in rural Bangladesh.

Sexually transmitted disease (STD) in rural Bangladesh is currently a topic of great concern. To date, little information is available in the literature regarding its prevalence. It is now known, however, that the current level of STD awareness among the rural population with regard to modes of transmission and means of prevention is inadequate. In 1994, the MCH-FP Extension Project (Rural) of ICDDR, B surveyed 8674 married women of reproductive age (MWRA) in 4 rural thanas to examine their awareness of STDs. The association between socio-demographic and programmatic factors (variables which affect STD information availability) and awareness of STDs was examined by both bivariate and multivariate analyses. Seven focus group discussions were conducted among groups of government health and family planning workers and paramedics to assess their knowledge of STDs and attitudes about their prevention. Only 12% of the original group had even a basic understanding about STDs and how to protect themselves from them. Twenty-five per cent of the women surveyed had ever heard of either syphilis or gonorrhoea. Of these women, less than half could mention specific mechanisms involved in the transmission of these diseases. Seven per cent reported that syphilis and gonorrhoea are transmitted through sexual intercourse. Thirteen per cent reported that the infections are transmitted from spouses to their partners. Four per cent reported that STDs can be spread by having multiple sexual partners. The results of logistic regression analysis indicate that awareness of STDs was higher among relatively older women than among younger women. Awareness of STDs was most strongly and positively associated with the education of both the women and their husbands. Awareness of STDs was also found to be higher among women who were more socially mobile (e.g. those who frequent cinemas or mothers' clubs). The findings of focus group discussions indicate that family planning and health care service providers have a moderate level of STD awareness. Modes of transmission and means of prevention, however, were areas of weakness. It will, therefore, be necessary, whether to prevent a potential STD epidemic or to combat current STD prevalence, to implement culturally acceptable and affordable means of disseminating knowledge in rural areas of Bangladesh. Training of health care providers will be an essential first step.

Adult

Mortality and survival among a cohort of drug injectors in Glasgow, 1982-1994.

There has been much speculation about the nature and extent of mortality among drug injectors in Glasgow. In order to determine injectors' mortality rate and compare this rate to the general population, identifier information from 459 drug injectors who received treatment for drug misuse in Glasgow between 1982 and 1994 was linked to the Scottish Mortality Register. The average duration of follow-up from cohort entry was 5.5 years and 10.2 years from commencement of drug injection. By the end of 1994, 53 cohort members had died. The average annual mortality rate of 1.8% was the same as that observed in a London cohort followed-up from 1969 to 1991. However, the excess mortality ratio (EMR) of 22.0 was almost double the London rate (11.9) because of the much lower average age of mortality (26.3 vs. 38.2 years). There was no significant time trend in EMR. Kaplan-Meier hazard analyzes show that younger patients and those who were HIV positive had significantly elevated mortality rates. The main cause of death was overdose, although it is unclear how many were accidental and how many intentional. Three of the six fatalities among HIV positive injectors were AIDS related. This study enables the first realistic assessment of the hypothesis that drug-related deaths in Glasgow are especially high. In relation to other populations of drug injectors, the annual mortality rate is comparable, although the average age of mortality is much lower in Glasgow. Consequently, in comparison to the general population, the mortality rate of drug injectors is higher in Glasgow compared to other cities.

Adolescent

IgA nephropathy in teaching hospitals of Dhaka.

A light and immunofluorescence microscopic study on renal biopsies were performed on 42 patients. Nephrotic syndrome with accompanying microhematuria and recurrent hematuria (Macroscopic/microscopic) with or without renal failure were the commonest indications for renal biopsy. Primary IgA nephropathy was diagnosed in five cases. Among the IgA nephropathy patients, the commonest light microscopic finding was mesangial proliferative glomerulonephritis. Macroscopic hematuria with proteinuria was the commonest feature. Three of the patients had hypertension at the time of renal biopsy. The age of the patients ranged from 19-38 years with a mean of 26 years. The high frequency of hypertension, degree of proteinuria and associated renal failure in one patient that it is a progressive disease. This preliminary study revealed that IgA nephropathy exists in Bangladesh. Larger samples need to be studied with a view to find out its prevalence and its peculiarities in this part of the world.

Adult

The structures of oligosaccharides isolated from the lipopolysaccharide of Moraxella catarrhalis serotype B, strain CCUG 3292.

The oligosaccharides from the lipopolysaccharides of Moraxella catarrhalis serotype B, strain CCUG 3292, were isolated after mild acid hydrolysis and separated by high-performance anion-exchange chromatography. The structures of the oligosaccharides were established by fast atom bombardment mass spectrometry and nuclear magnetic resonance spectroscopy. It is concluded that the oligosaccharides comprise a mixture of mainly a nona- and a deca-saccharide. [formula: see text] Smaller amounts of undeca-saccharides and of truncated forms, namely, hexa-, hepta-, and octa-saccharides, were also detected.

Carbohydrate Conformation

Gentamicin resistance gene transfer from Enterococcus faecalis and E. faecium to Staphylococcus aureus, S. intermedius and S. hyicus.

Transfer of gentamicin resistance from Enterococcus faecalis and E. faecium to Staphylococcus aureus, S. hyicus and S. intermedius was accomplished by filter mating. Transfer from E. faecalis was plasmid mediated and a probe to the gentamicin resistance gene aac(6')-aph(2") hybridized to HindIII fragments of various sizes (7.5, 6.2 and 4.7 kbp) of these plasmids. Transfer from E. faecium was apparently to the chromosome in 9 of 10 instances with HindIII fragments of 3.3 or 3.0 kbp hybridizing to the probe. These results are consistent with transposon mediated resistance. Plasmid transfers to S. intermedius were at much lower frequencies than to S. aureus or to S. hyicus but presumed transposon transfer direct to the chromosome was equal in all three species.

Burns

Prednisone improves renal function and proteinuria in human immunodeficiency virus-associated nephropathy.

PURPOSE: To determine if prednisone ameliorates the course of human immunodeficiency virus-associated nephropathy (HIV-AN). PATIENTS AND METHODS: Twenty consecutive HIV-infected adults with biopsy-proven HIV-AN (n = 17) or clinical characteristics of HIV-AN (n = 3) with serum creatinine concentrations > 177 mumol/L (2 mg/dL) or proteinuria > 2.0 g/d or both were prospectively evaluated and treated with prednisone at a dose of 60 mg/d for 2 to 11 weeks, followed by a tapering course of prednisone over a 2- to 26-week period. Serum creatinine concentration, 24-hour protein excretion, serum albumin, and steroid-related adverse effects were assessed before and after treatment. RESULTS: Nineteen patients had serum creatinine concentrations > 117 mumol/L (2 mg/dL). Two of them progressed to end stage renal disease (ESRD) in 4 to 5 weeks. In 17 patients serum creatinine levels decreased from 717 +/- 103 mumol/L (8.1 +/- mg/dL) (mean +/- SE) to 262 +/- 31 mumol/L (3.0 +/- 0.4 mg/dL) (P < 0.001). Five patients relapsed after prednisone was discontinued and were retreated. In these 5 the serum creatinine declined from 728 +/- 107 mumol/L (8.2 +/- 1.2 mg/dL) to 344 +/- 47 mumol/L (3.9 +/- 0.5 mg/dL) (P < 0.01) in response to the second course of prednisone. Twelve of 13 tested patients showed a reduction in 24-hour urinary protein excretion with an average decrement from 9.1 +/- 1.8 g/d to 3.2 +/- 0.6 g/d (P < 0.005). Serum albumin increased from 24.4 +/- 3.6 g/L to 29.3 +/- 2.6 g/L (P = NS) in the 11 patients with paired 24-hour urine collections for whom pre- and post-treatment determinations were available. In one non-azotemic patient with nephrotic syndrome, protein excretion declined from 15.2 to 2.2 g/day and the serum albumin increased from 4.0 g/L to 31.0 g/L. The 20 patients have been followed for a median of 44 weeks (range 8 to 107). Eight ultimately required maintenance dialysis. Eleven died from complications of HIV disease 14 to 107 weeks after institution of prednisone; none was receiving prednisone at the time of death. Seven are alive and free from ESRD a median of 25 weeks (range 8 to 81) from the initiation of prednisone therapy. Six patients developed a total of seven serious infections while receiving prednisone, including Mycobacterium avium-complex infection in 2 and CMV retinitis in 3. CONCLUSION: Prednisone improves serum creatinine and proteinuria in a substantial proportion of adults with HIV-AN. Corticosteroid-related side effects are not prohibitive. A prospective, randomized controlled trial is required to confirm these preliminary results.

Adult

Antibody response in rabbits to serotype-specific determinants in lipopolysaccharides from Moraxella catarrhalis.

Antibodies against the serotype determinant epitopes of Moraxella catarrhalis lipopolysaccharides (LPS) were demonstrated in sera from rabbits immunised with whole bacterial cells. Purified LPS preparations from eight strains of M. catarrhalis were used as antigens in enzyme-linked immunosorbent assays (ELISA) and immunoblotting. The serotype specificity of the antibodies was shown by neutralisation with LPS and with purified polysaccharide obtained from LPS prepared from strains belonging to different serotypes. In immunoblots, antisera against the A and B LPS serotypes reacted only with LPS of its own type, confirming the presence of type-specific antibodies. A weak band was observed with type A LPS and antibody to type C, indicating cross-reactivity between the A and C serotypes. This cross-reaction can be explained on the basis of the known chemical structure of the LPS of the different serotypes. After heterologous absorption of sera, bands were obtained with homologous LPS antigen. These results suggest that the predominant antibody response in rabbits to LPS from M. catarrhalis is serotype-specific, unlike that previously observed in infected human patients.

Animals

Estimation of the prevalence of non-insulin dependent diabetes mellitus in a rural area of Japan.

The objective of this paper is to describe a method of estimating the prevalence of non-insulin dependent diabetes mellitus (NIDDM) in a community. We first counted subjects with previously diagnosed NIDDM and those newly diagnosed by use of the 75-gram oral glucose tolerance test (OGTT). We then used the OGTT data to predict the prevalence of NIDDM at different levels of fasting plasma glucose (FPG) among the subjects who did not undergo the OGTT. Data were derived from 3,614 residents aged 20 years and older in a rural area where population-based screening for NIDDM was performed using FPG or post-prandial plasma glucose (PG). Of the 318 participants who underwent an OGTT in 1992, 35 (11.0%) were judged to have NIDDM by the 2-hour PG criterion. We applied the above-described method to the 1,179 subjects who had anFPG but failed to undergo the OGTT. The estimated prevalence of NIDDM, which included the previously diagnosed group, the newly diagnosed group and the expected group, was calculated. The estimated prevalence of diabetes in this population aged 20 years and older turned out to be 6.1% (95% CI: 5.3-6.9). As a validation study, the same method was applied to 220 subjects who did not undergo the OGTT in 1992 but did so in 1994. The actual prevalence of NIDDM among these subjects was compared to the prevalence expected from the 1992 data by our method. The actual value was within the 95% confidence interval of the expected value.

Adult

Partner notification program and possibility of including it in the HIV prevention strategies in Japan.

This article discusses the possibility of implementing partner notification program as a part of HIV prevention strategy in Japan. Relevant factors, like HIV seroprevalence, general population attitudes toward HIV, legislation, resources, barriers, behavioral changes, cost and effectiveness are analyzed in Japanese perspectives. Effectiveness of this program is also predicted based on the two informal contact tracing program in Japan. At the same time a review was made on the global perspectives of partner notification program and operational procedures are also outlined. Published literatures were investigated regarding prevalence of new HIV infection among the partners who underwent testing (11-39%), cost per new HIV positive case found (US $810-3,205), and secondary infection rate (11-20%) in Japan. Having considered all relevant factors we recommend that the partner notification program be implemented, initially in a limited area, then all over Japan. Further analysis on cost-benefit of this program remains to be done.

Adult

Diabetes mellitus among Swedish art glass workers--an effect of arsenic exposure?

OBJECTIVES: The purpose of this study was to search for evidence of an association between occupational arsenic exposure and diabetes mellitus, as implied by the relation of this disease to arsenic in drinking water in a recent study from Taiwan. METHODS: A case-referent analysis on death records of 5498 individuals in the art glass producing part of southeastern Sweden was performed. Out of all the enrolled subjects, 888 were glass workers. According to occupational title, glassblowers, foundry workers, and unspecified workers were regarded as potentially exposed to arsenic. Persons with a diagnosis of diabetes mellitus either as an underlying or contributing cause of death were considered cases. Referents were decedents without any indication of cancer, cardiovascular disease, or diabetes. RESULTS: A slightly elevated risk [Mantel-Haenszel odds ratio (MH-OR) 1.2, 95% confidence interval (95% CI) 0.82-1.8] was found for diabetes mellitus among the glassworks employees, especially in combination with cardiovascular disease (MH-OR 1.4, 95% CI 0.81-2.3). For the glassblowers, other foundry workers and unspecified glassworkers probably exposed to arsenic, the M-H odds ratio was 1.4 (95% CI 0.92-2.2). Unspecified glass workers, who probably included persons with high exposure, carried the higher risk (MH-OR 1.8, 95% CI 1.1-2.8). CONCLUSIONS: The observations from this study provide limited support for the possibility that occupational arsenic exposure could play a role in the development of diabetes mellitus. Many other metallic compounds are also used in art glass production, however, and there is a possibility of confounding.

Age Distribution

A study of prolonged pyrexia in Dhaka.

In a prospective study conducted in the Institute of Postgraduate Medicine & Research (IPGMR), Dhaka, 212 patients with prolonged pyrexia were thoroughly evaluated clinically and with the help of laboratory investigations with a view to reaching the diagnosis. Their clinical and laboratory data were recorded. Clinical features pertaining to a particular organ gave appropriate clue in 52% cases. Imaging techniques were instrumental in 24%, microbiological or serological investigations in 35%, invasive procedures were diagnostic in 42%, laparotomy had to be resorted to in five cases. Infectious diseases were the commonest causes of prolonged pyrexia accounting for about 63.21% of cases followed by neoplasms (12.74%) and connective tissue disorders (10.85%). Tuberculosis was the most common infection (24.53% of all cases) followed by enteric fever (12.74%) and visceral leishmaniasis (9.43%). Pleura was the commonest seat for tuberculosis followed by lymph nodes and abdomen. Leukemias were the commonest neoplasm and SLE the commonest connective tissue disorder presenting with prolonged fever. Several fundamental observations were made in the study. Infections are the commonest cause of prolonged fever in our community, neoplasms and connective tissue disorders are also not rare. Secondly, patients with temperature between 100 to 101 degrees F should not be denied evaluation with the apprehension of unnecessarily investigating for habitual hyperthermia, as the condition was distinctly rare in the series. Thirdly, analysis of materials from organs or systems suspected to be abnormal clinically or by simple imaging techniques had high diagnostic yield. Finally, usual causes of prolonged fever are illnesses ordinarily encountered in clinical practice, pyrexia becomes protracted either because the presentation is atypical or incomplete, or because we fail to make proper use of available clinical or paraclinical information.

Adolescent

Structural studies of the O-antigen oligosaccharides from two strains of Moraxella catarrhalis serotype C.

The oligosaccharide parts from Moraxella (Branhamella) catarrhalis serotype C lipooligosaccharides were isolated by mild acid hydrolysis followed by gel permeation chromatography. Four different oligosaccharides could be identified from strain RS26 and two from strain RS10. The structures of the O-oligosaccharides were established by methylation analyses, mass spectrometry, and NMR spectroscopy. It is concluded that the oligosaccharide O-antigens from RS26 are a mixture of octa-, deca-, and undeca-saccharides, and most likely a heptasaccharide. Strain RS10 contains the deca- and the undeca-saccharide only. The structures for the oligosaccharides are shown below. [formula: see text] OS(7) [formula: see text] OS(8) [formula: see text] OS(10) [formula: see text] OS(11) Methylation analysis of the intact lipooligosaccharides showed that two Kdo residues were present, one terminal and one 4,5-substituted residue. It also showed that they consisted of a lipid A portion with 6-substituted glucosamine residues.

Carbohydrate Sequence