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Biomedical subjects

M S Islam

Publications and source records attributed to M S Islam.

At least 55 records · Page 3Linked to original sources
PubMed1997

Evaluation of culture, histological examination, serology and the rapid urease test for diagnosis of Helicobacter pylori in patients with dyspepsia in Bangladesh.

Helicobacter pylori, a gram-negative, microaerophilic bacterium, has been established to have a causal association with chronic gastritis, peptic ulcer, gastric adenocarcinoma, and low-grade lymphoma. The present study was undertaken to evaluate the efficacy of culture, histological examination, the rapid urease test, and serology for the diagnosis of H. pylori infection. A total of 45 consecutive subjects with various upper gastrointestinal symptoms were included in this study. The rates of diagnosis of H. pylori infection were 51.1%, 55.6%, 82.2%, and 93.3%, by culture, rapid urease test (RUT), histological examination, and serology, respectively. The sensitivity, specificity, and positive and negative predictive values were 95.5%, 82.6%, 84.0%, and 95.0%, respectively for RUT; 95.5%, 30.4%, 56.8%, and 87.5% for histological examination; 100%, 13.6%, 54.8% and 100% for serology.

Adult↗
PubMed1997

Detection of non-culturable Shigella dysenteriae 1 from artificially contaminated volunteers' fingers using fluorescent antibody and PCR techniques.

Epidemiological studies have demonstrated that hands may be an important vehicle for transmission of shigellosis. The present study was carried out to find out the survival potential of Shigella dysenteriae 1 on fingers of volunteers. Finger surface was inoculated with 10(5) cfu of S. dysenteriae 1 and then the bacteria were detected using conventional culture, PCR and fluorescent antibody (FA) techniques after different time intervals. It was found that S. dysenteriae 1 survived for up to one hour in culturable form but up to four hours in non-culturable form on human fingers. The non-culturable S. dysenteriae was detected by PCR and FA techniques. This study elaborates on the role that fingers have in the transmission of shigellae.

DNA, Bacterial↗
PubMed1997

More than 17 years of peritoneal dialysis: a case report.

Very few patients have undergone long-term peritoneal dialysis (PD). We report a case of a female patient on PD since 26 May 1979. Suffering from malignant hypertension, she developed renal failure in April 1979. The renal biopsy showed a severe vascular nephropathy. She was 50 years old, her body weight (BW) was 45 kg, and her height was 1.49 m. She refused hemodialysis. A Tenckhoff catheter was installed, and 12-hour intermittent PD (IPD), three times a week, was started in the dialysis center. Ten months later, she began nightly home IPD. In March 1985 she started continuous ambulatory PD (CAPD); she was nearly anuric. During the following years, she developed renal osteodystrophy and suffered from repeated hyperparathyroidism requiring multiple surgical interventions, osteomalacia, pseudotumoral calcinosis, and, finally, adynamic bone disease. She is now 67.5 years old, her BW is 34 kg, and she is still using CAPD. This patient has the same Tenckhoff catheter. She never developed peritonitis or an exit-site or tunnel infection. She used acetate dialysis solution for nearly six years and then lactate solution. Presently her peritoneal permeability is of the high-average type; dialysis adequacy (weekly Kt/V: 2.15, weekly peritoneal clearance: 58 L/1.73 m2) as well as nutritional parameters are satisfactory. She has moderate anemia without erythropoietin treatment. She maintains a good quality of life. Although the patient lost 11 kg in 17 years, she has maintained good nutritional status. Dialysis adequacy could be achieved despite anuria for more than 11 years. Small body size, absence of infection and catheter-related problems, healthy peritoneal membrane, good acceptance of the technique, and vigilance towards dietary habits may be the keys for satisfactory long-term PD.

Aged↗
PubMed1997

Multiple papilloma of the larynx in an adult--a case report.

Multiple papilloma of the larynx commonly affects the juvenile subjects. Only a few adult cases have been reported. Such a rare case in Bangladesh, is reported here. Twenty five years old one male patient was admitted into Sir Salimullah Medical College & Mitford Hospital with the complaints of hoarseness of voice & dysponea. He was diagnosed as papilloma clinically and histopathologically, and treated with tracheostomy & microlaryngoscopic excision of the masses. The patient was readmitted after 3 months with recurrence of papilloma at the same site and the growth was excised under anaesthesia. The past history of his illness revealed that he underwent to more surgeries for the same condition. The patient was lost to follow up.

Adult↗
PubMed1996

Insulin exocytosis and glucose-mediated increase in cytoplasmic free Ca2+ concentration in the pancreatic beta-cell are independent of cyclic ADP-ribose.

Stimulation of pancreatic beta-cells by glucose gives rise to an increase in the cytoplasmic free calcium concentration ([Ca2+]i) and exocytosis of insulin. Cyclic adenosine 5'-diphosphate ribose (cADPR), a metabolite of beta-NAD+, has been reported to increase [Ca2+]i in pancreatic beta-cells by releasing Ca2+ from inositol 1,4,5-trisphosphate-insensitive intracellular stores. In the present study, we have examined the role of cADPR in glucose-mediated increases in [Ca2+]i and insulin exocytosis. Dispersed ob/ob mouse beta-cell aggregates were either pressure microinjected with fura-2 salt or loaded with fura-2 acetoxymethyl ester, and [Ca2+]i was monitored by microfluorimetry. Microinjection of beta-NAD+ into fura-2-loaded beta-cells did not increase [Ca2+]i nor did it alter the cells' subsequent [Ca2+]i response to glucose. Cells microinjected with the cADPR antagonist 8NH2-cADPR increased [Ca2+]i in response to glucose equally well as those injected with cADPR. Finally, the ability of cADPR to promote exocytosis of insulin in electropermeabilized beta-cells was investigated. cADPR on its own did not increase insulin secretion nor did it potentiate Ca2+-induced insulin secretion. We conclude that cADPR neither plays a significant role in glucose-mediated increases in [Ca2+]i nor interacts directly with the molecular mechanisms regulating exocytosis of insulin in normal pancreatic beta-cells.

Adenosine Diphosphate Ribose↗
PubMed1996

Systemic uptake and clearance of chloroform by hairless rats following dermal exposure. I. Brief exposure to aqueous solutions.

The systemic uptake of chloroform from dilute aqueous solutions into live hairless rats under conditions simulating dermal environmental exposure was studied. Whole blood was sampled during a 30-min immersion of an animal within water containing a known concentration of chloroform and then for 5.5 h following its removal from the bath. The amount of chloroform systemically absorbed was determined by comparing the AUCs of the blood concentration vs. time plots from dermal exposure to that obtained after i.v. infusion (for a period of 30 min) of an aqueous solution containing a known amount of chloroform (positive control). Although dermal data implied two-compartment disposition characteristics, i.v. infusion data fit best to a three-compartment disposition. Linear pharmacokinetics was observed both by i.v. administration and percutaneous absorption at the dose levels studied. Chloroform was detected in the rat blood as early as 4 min following exposure. Our findings suggest that about 10.2 mg of chloroform was systemically absorbed after dermal exposure of a rat to an aqueous solution of 0.44 mg/ml. This amount is substantially higher than the predictions of mathematical risk-models put forth by some investigators. However, when expressed as the "effective" permeability coefficient (Kpeff), close agreement was noticed between our value and those estimated by others using physiologically based pharmacokinetic (PBPK) models. Also, in terms of Kpeff, reasonable agreement existed between our and another investigator's past estimates of uptake based on depletion of bath level of chloroform and the actual uptake measured in our current experiments. The estimated onset of systemic entry seen here is entirely consistent with our estimate of how long it takes to establish the diffusion gradient across the stratum corneum based on tape stripping.

Animals↗
PubMed1996

A simple filtration method to remove plankton-associated Vibrio cholerae in raw water supplies in developing countries.

Plankton to which cells of Vibrio cholerae O1 and/or O139 were attached was introduced into 0.5% Instant Ocean microcosms maintained at 25 degrees C. The bulk of the plankton and associated particulates was removed with a filter constructed from either nylon net and one of several different types of sari material, the latter being very inexpensive and readily available in villages in Bangladesh, where V. cholerae is endemic. V. cholerae was enumerated before and after filtration to evaluate the efficiency of the filtration procedure. The results obtained indicate that 99% of V. cholerae, i.e., those cells attached to plankton, were removed from the water samples. Epidemic strains of V. cholerae O1 and O139 from various geographical sources, including Bangladesh, Brazil, India, and Mexico, were included in the experiments. Removal of vibrios from water by this simple filtration method was found to yield consistent results with all strains examined in this study. Thus, it is concluded that a simple filtration procedure involving the use of domestic sari material can reduce the number of cholera vibrios attached to plankton in raw water from ponds and rivers commonly used for drinking. Since untreated water from such sources serves as drinking water for millions of people living in developing countries (e.g., Bangladesh), filtration should prove effective at reducing the incidence and severity of outbreaks, especially in places that lack fuel wood for boiling water and/or municipal water treatment plants. The results of this study provide the basis for determining such reductions, which are to be carried out in the near future.

Animals↗
PubMed1996

[Anterior uveitis with ankylosing spondylitis and HLA].

We investigated the relationship between anterior uveitis with ankylosing spondylitis (AS) and human leukocyte antigen (HLA) alleles. Forty patients were studied, 19 with anterior uveitis and 21 without it. No deviation in the frequencies of HLA-B27 antigen and related alleles were observed between the two groups of patients. Twelve cases (63.2%) with anterior uveitis had expressed HLA-DR8 (DRB1 0803). On the other hand, only 1 case had expressed the same antigen and this difference was statistically significant (relative risk: 34.3 Pc < 0.007) as we reported previously. We found HLA-DR8 was a candidate for susceptibility to anterior uveitis in AS.

Alleles↗
PubMed1996

Survival of Shigella flexneri in artificial aquatic environment: effects of different physicochemical stress factors.

Survival of bacteria in aquatic environment is influenced by the prevailing physicochemical characteristics of water. A study was carried out to assess the effects of temperature, pH, and salinity of water on the survival of Shigella flexneri in laboratory microcosms. Survival of S. flexneri was assessed by viable counts of Shigella on MacConkey agar plates. At pH 7.0 and temperature of 4 degrees C, S. flexneri survived longer in 0.5% salinity than in salt-free distilled water, while at pH 7.0 and at higher temperatures (25 degrees C and 37 degrees C), the bacteria survived longer in distilled water than in 0.5% salinity. It was also observed that 2.0% NaCl solution was detrimental to bacterial survival at pH 8.0 and temperature of 37 degrees C. Survival times of the viable cells increased with reduction of temperatures and salinity. These findings demonstrated that survival of S. flexneri in the aquatic environment is greatly influenced by physicochemical factors.

Adaptation, Physiological↗
PubMed1995

Effects of caffeine on cytoplasmic free Ca2+ concentration in pancreatic beta-cells are mediated by interaction with ATP-sensitive K+ channels and L-type voltage-gated Ca2+ channels but not the ryanodine receptor.

In the pancreatic beta-cell, an increase in the cytoplasmic free Ca2+ concentration ([Ca2+]i) by caffeine is believed to indicate mobilization of Ca2+ from intracellular stores, through activation of a ryanodine receptor-like channel. It is not known whether other mechanisms, as well, underlie caffeine-induced changes in [Ca2+]i. We studied the effects of caffeine on [Ca2+]i by using dual-wavelength excitation microfluorimetry in fura-2-loaded beta-cells. In the presence of a non-stimulatory concentration of glucose, caffeine (10-50 mM) consistently increased [Ca2+]i. The effect was completely blocked by omission of extracellular Ca2+ and by blockers of the L-type voltage-gated Ca2+ channel, such as D-600 or nifedipine. Depletion of agonist-sensitive intracellular Ca2+ pools by thapsigargin did not inhibit the stimulatory effect of caffeine on [Ca2+]i. Moreover, this effect of caffeine was not due to an increase in cyclic AMP, since forskolin and 3-isobutyl-1-methylxanthine (IBMX) failed to raise [Ca2+]i in unstimulated beta-cells. In beta-cells, glucose and sulphonylureas increase [Ca2+]i by causing closure of ATP-sensitive K+ channels (KATP channels). Caffeine also caused inhibition of KATP channel activity, as measured in excised inside-out patches. Accordingly, caffeine (> 10 mM) induced insulin release from beta-cells in the presence of a non-stimulatory concentration of glucose (3 mM). Hence, membrane depolarization and opening of voltage-gated L-type Ca2+ channels were the underlying mechanisms whereby the xanthine drug increased [Ca2+]i and induced insulin release. Paradoxically, in glucose-stimulated beta-cells, caffeine (> 10 mM) lowered [Ca2+]i. This effect was due to the fact that caffeine reduced depolarization-induced whole-cell Ca2+ current through the L-type voltage-gated Ca2+ channel in a dose-dependent manner. Lower concentrations of caffeine (2.5-5.0 mM), when added after glucose-stimulated increase in [Ca2+]i, induced fast oscillations in [Ca2+]i. The latter effect was likely to be attributable to the cyclic AMP-elevating action of caffeine, leading to phosphorylation of voltage-gated Ca2+ channels. Hence, in beta-cells, caffeine-induced changes in [Ca2+]i are not due to any interaction with intracellular Ca2+ pools. In these cells, a direct interference with KATP channel- and L-type voltage-gated Ca(2+)-channel activity is the underlying mechanism by which caffeine increases or decreases [Ca2+]i.

Adenosine Triphosphate↗
PubMed1995

Why treatment centres failed to prevent cholera deaths among Rwandan refugees in Goma, Zaire.

In July, 1994, in one of the worst cholera outbreaks in recent times, an estimated 12,000 Rwandan refugees died in Goma in eastern Zaire. The Vibrio cholerae strains were resistant to tetracycline and doxycycline, the commonly used drugs for cholera treatment. Despite the efforts of international organisations, which provided medical relief by establishing treatment centres in Goma, mortality from the disease was much higher than expected. In the area of Muganga camp, which had the largest concentration of refugees and where most of the medical aid organisations were active, the highest reported case-fatality ratio for a single day was 48%. The slow rate of rehydration, inadequate use of oral rehydration therapy, use of inappropriate intravenous fluids, and inadequate experience of health workers in management of severe cholera are thought to be some of the factors associated with the failure to prevent so many deaths during the epidemic. In one of the temporary treatment centres with the worst case-fatality record, our team showed that improvement of these factors could increase the odds of survival of cholera patients even in a disaster setting.

Ambulatory Care Facilities↗
PubMed1995

Post-defecation handwashing in Bangladesh: practice and efficiency perspectives.

Inadequate handwashing after defecation and anal cleaning practices in the Indian subcontinent is an important source of faeco-oral transmission of enteric diseases. To better understand the process as traditionally practised, 90 women in semi-rural Bangladesh were observed washing hands after defecation. Several components of handwashing practices were identified: the cleaning agent, using left or both hands; frequency of rubbing hands, type and amount of water used to wash, and the drying of hands on the wearer's clothes. A subsequent experiment was conducted to assess the effect of currently practised handwashing and drying according to standardised procedure on faecal coliform count of hands. As a rubbing agent, soil was commonly used (40%); soap was used by 19% and was reported unaffordable by about 81% of the non-users. Good handwashing behaviour was positively associated with better social and economic indicators including education of the women observed. Both hands were unacceptably contaminated after traditional handwashing (the geometric mean count of left was 1,995 and right hand was 1,318 faecal coliform units/hand). After standardising the observed components of handwashing procedures the use of any rubbing agent, i.e. soil, ash or soap, produced similar acceptable cleaning. Use of a rubbing agent (e.g. soil, ash or soap), more rubbing (i.e. six times), rinsing with safer water (e.g. 2 litres of tubewell water) and drying with a clean cloth or in the air produced acceptable bacteriological results. Components of traditional handwashing practices were defined through careful observation, and experiments on handwashing with standardised components showed that efficient and affordable options for handwashing can be developed; this knowledge should be helpful in disease control programmes.

Bangladesh↗
PubMed1995

Uptake of chloroform by skin during short exposures to contaminated water.

Uptake of chloroform into hairless rat stratum corneum from dilute aqueous solutions was studied using tape-stripping to determine amounts deposited in the skin under various environmental exposure scenarios. The length of exposure of sedated animals to the chloroform-containing medium, the frequency and duration of tape-stripping, and the number of tape-strips per location were varied to map the stratum corneum substantivity of chloroform. Eight minutes immersion of the rat within a well-stirred solution at 36 degrees C was found to be adequate time for the gradient to be established fully across the stratum corneum. Penetration was progressively deeper as the exposure time increased. Substantial evaporative loss of chloroform from the aqueous medium of application seem to be responsible for lower cumulative amounts taken up when the same solution was held on the rat's skin within a stainless steel template of fixed area. Of the total uptake (29 mg) from a dilute stirred solution of chloroform (0.44 mg/ml) at 36 degrees C, about 95% was systematically absorbed after a 30 min exposure as determined by residuals (measurement of bath concentrations).

Animals↗
PubMed1995

Characterization of Aeromonas trota strains that cross-react with Vibrio cholerae O139 Bengal.

It has previously been shown that Vibrio cholerae O139 Bengal shares antigens with V. cholerae serogroups O22 and O155. We detected six surface water isolates of Aeromonas trota that agglutinated in polyclonal antisera to V. cholerae O139 and V. cholerae O22 but not in antiserum to V. cholerae O155. On the basis of agglutinin-absorption studies, the antigenic relationship between the cross-reacting bacteria were found to be in an a,b-a,c fashion, where a is the common antigenic epitope and b and c are unique epitopes. The antigen sharing between A. trota strains and V. cholerae O139 was confirmed in immunoblot studies. However, A. trota strains did not react with two monoclonal antibodies specific for V. cholerae O139 and, consequently, tested negative in the Bengal SMART rapid diagnostic test for V. cholerae O139 which uses one of the monoclonal antibodies. A polyclonal antiserum to a cross-reacting A. trota strain cross-protected infant mice against cholera on challenge with virulent V. cholerae O139. All A. trota strains were cytotoxic for HeLa cells, positive for adherence to HEp-2 cells, and weakly invasive for HEp-2 cells; one strain was heat-stable toxin positive in the suckling mouse assay; however, all strains were negative for cholera toxin-like enterotoxin. Studies on bacteria that share somatic antigen with V. cholerae O139 may shed further light on the genesis of V. cholerae O139.

Aeromonas↗
PubMed1995

Isolation of sucrose late-fermenting and nonfermenting variants of Vibrio cholerae O139 Bengal: implications for diagnosis of cholera.

The sucrose-containing selective medium thiosulfate-citrate-bile salt-sucrose agar missed a sucrose nonfermenting and four sucrose late-fermenting variant strains of Vibrio cholerae O139 Bengal from diarrheal stools. These strains were, however, correctly identified as V. cholerae O139 on a sucrose-deficient selective medium, taurocholate-tellurite-gelatin agar.

Cholera↗
PubMed1995

Abundance of Aeromonas spp. in river and lake waters in and around Dhaka, Bangladesh.

Aeromonas spp. are widely distributed in the aquatic environment. In Bangladesh, seasonal distribution of these organisms in aquatic environment was studied during July 1986-August 1987. Water, sediment, plant, and plankton samples were collected monthly from the Dhanmondi lake and the Buriganga river during the study period. Aeromonas spp. were isolated from all samples throughout the year. The seasonal peak of Aeromonas spp. was observed in warmer months (April-May) in the surface waters. In the sediment, the highest peak was observed in March and August. In most plants, the highest peak was observed during the winter months (December-February). In the plankton samples of the Dhanmondi lake and the Buriganga river, the highest counts were obtained in July and February respectively. In both the sampling sites, plants were observed to contain more Aeromonas than did the water and sediment samples. The prevalence of Aeromonas spp. throughout the year in aquatic environment suggests the autochthonous nature of these organisms and that there is an association of Aeromonas with the aquatic environment.

Aeromonas↗