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Biomedical subjects

M A Chowdhury

Publications and source records attributed to M A Chowdhury.

At least 19 recordsLinked to original sources
PubMed2002

Comparative study between tubotympanic and atticoantral types of chronic suppurative otitis media.

This prospective study was done to compare the different aspects of tubotympanic (group I) and atticoantral types (group II) of chronic suppurative otitis media. The study included 200 patients of chronic suppurative otitis media, of them 100 were of tubotympanic type and 100 were with atticoantral disease. The age (mean +/- SD) of group I and II were 17 +/- 2.7 years and 12 +/- 2.3 years respectively (P < 0.05). The majority of the patients having poor socio-economic condition 69% in group I and 87% in-group II. In both groups, slum dwellers with bathing habit in pond or river and illiterate were more sufferer (P < 0.05). There was central perforation in all patients in-group I, and in-group II, 67% were with attic and 33% were with marginal perforations. In group I, aural discharge was mucoid or mucopurulent in majority of cases 80% and in-group II foul smelling scanty ear discharge was from 88% of subjects. In atticoantral type, hearing impairment was more than tubotympanic disease. Complications were more in atticoantral type of disease. In-group II, post auricular sinus 25% was the commonest extracranial complication followed by subperiosteal abscess 18%, and meningitis 10% was the commonest intracranial complication followed by brain abscess 8%. In tubotympanic type conservative treatment with reconstructive surgery were the treatment of choice, whereas radical or some modifications of radical surgery (with or without reconstruction) were the treatment plan for atticoantral disease. Among the groups the mortality rate was only 4% in-group II and was due to intracranial complications. The study recommends early detection and effective surgical treatment of the disease to improve the situation.

Adolescent↗
PubMed2000

Retention versatility of silica-supported comb-shaped crystalline and non-crystalline phases in high-performance liquid chromatography.

Silica-supported comb-shaped polymer (Sil-ODA18) provided a specific selectivity towards aromatic and non-aromatic solutes. Selectivity of Sil-ODA18 and ODS (polymeric and monomeric) columns towards polycyclic aromatic hydrocarbons and geometric isomers have been discussed in respect of molecular shapes and sizes. The retention versatility of this phase arises from the orientation change on transition from the ordered crystalline to the less ordered non-crystalline state. Selectivity in the crystalline and non-crystalline regions of Sil-ODA18 is similar to that of polymeric and monomeric ODS phases, respectively. Sil-ODA18 column also exhibited the characteristic temperature dependency of liquid-crystalline phases, i.e., an increase in retention with increasing temperature on transition from crystalline to isotropic state.

Chromatography, High Pressure Liquid↗
PubMed2000

Vegetarian diet in the treatment of fibromyalgia.

Brain tryptophan is low in fibromyalgia. Intake of protein rich in large neutral amino acids is reported to lower brain tryptophan. This study was undertaken to assess whether any reduction of such proteins by exclusion of animal protein from the diet reduced pain and morbidity in fibromyalgia patients. It was an open, randomized controlled trial. 37 subjects with fibromyalgia were enrolled in the vegetarian diet and 41 in the amitriptyline groups. The outcome was assessed with the help of frequencies of fatigue, insomnia & non-restorative sleep, pain score on a 10-point VAS and tender point count. Fatigue, insomnia and non-restorative sleep were present in 41, 26 and 32 subjects before and in 3, 0 and 0 subjects respectively at six weeks of treatment in the amitriptyline group. The pain score and tender point count were 6.2 +/- 1.9 & 16.1 +/- 2.3 before and 2.3 +/- 1.3 & 6.4 +/- 3.0 after treatment. All these differences were significant (P < 0.001). In the vegetarian diet group, fatigue, insomnia and non-restorative sleep were present in 36, 24 and 27 subjects before and in 34, 29 and 29 subjects at six weeks of treatment. The pain score and tender point count were 5.7 +/- 1.8 and 15.7 +/- 2.4 before and 5.0 +/- 1.8 & 14.7 +/- 3.6 after treatment. All these differences were insignificant except that in the pain score. The decrease in the pain score, though significant, was much smaller than that in the amitriptyline group. So, it may be concluded that vegetarian diet is a poor option in the treatment of fibromyalgia.

Adult↗
PubMed1999

Laboratory evaluation of selected larvicides and insect growth regulators against field-collected Culex quinquefasciatus larvae from urban Dhaka, Bangladesh.

Five organophosphates (OPs) (chlorpyrifos, chlorpyrifos methyl, fenthion, malathion, and temephos), 3 pyrethroids (bifenthrin, cypermethrin, and permethrin), 1 phenyl pyrazole (fipronil), 2 microbial pesticides (Bacillus thuringiensis serovar. israelensis [B.t.i.] and Bacillus sphaericus), and 3 insect growth regulators (IGRs) (diflubenzuron, methoprene, and pyriproxyfen) were evaluated against field-collected Culex quinquefasciatus larvae from urban Dhaka, Bangladesh. The LC90 values of all OPs, except for temephos (LC90 = 0.0096 ppm), were high, ranging from 0.13 ppm (fenthion) to 2.882 ppm (chlorpyrifos methyl). Pyrethroid LC90 values were 0.021 ppm (bifenthrin), 0.00061 (cypermethrin), and 0.017 ppm (permethrin). Fipronil exhibited a superior activity with LC90 value of 0.000896 ppm. Technical powders of B.t.i. and B. sphaericus (VectoBac TP and VectoLex TP) were considered highly effective against the Cx. quinquefasciatus larvae. The IGRs also were effective with pyriproxyfen (LC90 = 0.0011 ppm), being 3 times and 47 times more active than diflubenzuron (LC90 = 0.0034 ppm) and methoprene (LC90 = 0.052 ppm), respectively. In general, toxicity ranking of chemicals and microbials tested was phenyl pyrazole > IGRs > pyrethroids > microbials > OPs.

Animals↗
PubMed1997

Effect of alum on free-living and copepod-associated Vibrio cholerae O1 and O139.

The effects of alum [KAl(SO4)2] on free-living and copepod-associated Vibrio cholerae O1 and O139 were investigated by using plate counts and immunofluorescence direct viable counting (DVC). Growth of alum-treated cells in 0.5/1000 Instant Ocean seawater was inhibited, i.e., no growth was obtained on Luria-Bertani (LB) agar or thiosulfate-citrate-bile salt-sucrose (TCBS) agar. However, a significant number of the inhibited cells maintained viability, as measured by DVC. In comparison, a significant number of V. cholerae organisms associated with zooplankton, most of which were crustacean copepods, were viable but nonculturable, with only a small number of cells retaining culturability on LB and TCBS agar. Both DVC and viable plate counts (CFU) were significantly greater for V. cholerae O1 and O139 associated with zooplankton than for V. cholerae in water alone, i.e., without copepods. It is concluded that alum is an effective coagulant but not an effective killing agent for V. cholerae and that association with copepods offers protection for V. cholerae O1 and O139 against alum and chlorine treatments.

Alum Compounds↗
PubMed1997

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↗
PubMed1996

Complications and outcome of percutaneous endoscopic gastrostomy in different patient groups.

A retrospective study of percutaneous endoscopic gastrostomy (PEG) was performed to evaluate the complications of PEG and determine the role of prophylactic antibiotics in preventing early wound infection and to evaluate the outcome of patients in different groups (neurological disease, head injury, AIDS). Percutaneous endoscopic gastrostomy was performed on 50 patients between March 1991 and November 1993 and the survey was completed in July 1994. The average time to PEG placement post-cerebrovascular accident or head injury was 5 weeks. No deaths were attributable to the procedure. Four of 50 (8%) patients died in the first 30 days (early mortality). Wound infection (early eight, late five) was the most common complication: two of 13 patients receiving prophylactic antibiotics and six of 37 not receiving antibiotics had early wound infection. At completion of follow-up 19 of 26 patients with neurological disease had died (median survival = 370 days), three resumed oral feeding and four continued PEG feeding. All head injury patients (n = 6) were alive and had resumed oral feeding; five returned home. All AIDS patients (n = 7) died within 12 months (median survival = 138 days), although improved nutritional state was found after gastrostomy feeding. In conclusion, PEG placement is a useful procedure to assist feeding in multiple patient groups. Wound infection is a common but not life threatening complication. The need for prophylactic antibiotics to prevent early wound infection has not been proven. The 5 week delay in PEG insertion may contribute to lower early mortality. The 100% survival rate in head injury patients may reflect their young age and absence of underlying medical illness. In AIDS patients, improved nutritional state is not known to translate into better quality of life or prolonged survival.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Potential virulence of viable but nonculturable Shigella dysenteriae type 1.

We examined a virulent strain of Shigella dysenteriae type 1 after induction into the viable but nonculturable (VBNC) state for its ability to (i) maintain the Shiga toxin (stx) gene; (ii) maintain biologically active Shiga toxin (ShT); and (iii) adhere to intestinal epithelial cells (Henle 407 cell line). PCR was used to amplify the stx gene from VBNC cells of S. dysenteriae type 1, thereby establishing its presence even when cells are in the VBNC state. VBNC S. dysenteriae type 1 ShT was monitored by the enzyme-linked immunosorbent assay with mouse monoclonal antibodies against the B subunit of ShT and affinity-purified rabbit polyclonal antibodies against ShT. We used the Henle 407 cell line to study the adhesive property of VBNC S. dysenteriae type 1 cells in a series of tissue culture experiments. Results showed that VBNC S. dysenteriae type 1 not only maintained the stx gene and biologically active ShT but also remained capable of adhering to Henle 407 cells. However, S. dysenteriae type 1 cells lost the ability to invade Henle 407 cells after entering the VBNC state. From results of the study, we conclude that VBNC cells of S. dysenteriae type 1 retain several virulence factors and remain potentially virulent, posing a public health problem.

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

Serogroup conversion of Vibrio cholerae non-O1 to Vibrio cholerae O1: effect of growth state of cells, temperature, and salinity.

Recently, we reported the occurrence of seroconversion from Vibrio cholerae non-O1 to V. cholerae O1, but little is known about the environmental and physiological factors influencing seroconversion. We investigated effects of temperature (4, 25, and 35 degrees C) and salinity ( < 0.05 and 10%0.), as well as the stage of growth of cells, on serogroup conversion. Seroconversion of V. cholerae occurred under various environmental conditions. However, the rate of seroconversion in natural water ( < 0.5% salinity) and synthetic seawater microcosms (10%0 salinity), employing cells harvested from stationary phase culture, was approximately 2 logs higher than cells harvested from cultures in the logarithmic phase (i.e., 10(5) versus 10(3) per 10(10) cells. Thus, the physiological state of the cells, and to a lesser degree, temperature and salinity, is an important factor in the conversion of V. cholerae from non-O1 to O1 serogroup.

Antigens, Bacterial↗
PubMed1996

Deaths in visceral leishmaniasis (Kala-azar) during treatment.

Twenty-seven out of five hundred and fifty three patients hospitalized for visceral leishmaniasis (Kala-azar) died during treatment with sodium antimony gluconate. Data from these patients were evaluated to find out the cause of death. Eight patients had associated diseases such as pulmonary tuberculosis (3), severe malnutrition (1), acute gastroenteritis (1), spleenic infarction (1), acute renal failure (1) and atrial septal defect (1) which could be attributed to death. Twelve patients developed spontaneous haemorrhages from nose, gums and gastrointestinal tract and died, despite of adequate supportive measures. Seven other patients who were improving slowly with antimony therapy died unexpectedly. Though, cause of death could be explained in some patients with associated disease conditions, it could not be explained in others as significant clinical manifestations, haematological, biochemical and electrocardiographic alterations were not evident prior to death. Our impression is that mortality in Kala-azar patients during standard antimonial therapy is more related to the drug rather than the disease process.

Adolescent↗
PubMed1995

Enterobacterial repetitive intergenic consensus sequences and the PCR to generate fingerprints of genomic DNAs from Vibrio cholerae O1, O139, and non-O1 strains.

Enterobacterial repetitive intergenic consensus (ERIC) sequence polymorphism was studied in Vibrio Cholerae strains isolated before and after the cholera epidemic in Brazil (in 1991), along with epidemic strains from Peru, Mexico, and India, by PCR. A total of 17 fingerprint patterns (FPs) were detected in the V. cholerae strains examined; 96.7% of the toxigenic V. cholerae O1 strains and 100% of the O139 serogroup strains were found to belong to the same FP group comprising four fragments (FP1). The nontoxigenic V. cholerae O1 also yielded four fragments but constituted a different FP group (FP2). A total of 15 different patterns were observed among the V. cholerae non-O1 strains. Two patterns were observed most frequently for V. cholerae non-01 strains, 25% of which have FP3, with five fragments, and 16.7% of which have FP4, with two fragments. Three fragments, 1.75, 0.79, and 0.5 kb, were found to be common to both toxigenic and nontoxigenic V. cholerae O1 strains as well as to group FP3, containing V. cholerae non-O1 strains. Two fragments of group FP3, 1.3 and 1.0 kb, were present in FP1 and FP2 respectively. The 0.5-kb fragment was common to all strains and serogroups of V. cholerae analyzed. It is concluded from the results of this study, based on DNA FPs of environmental isolates, that it is possible to detect an emerging virulent strain in a cholera-endemic region. ERIC-PCR constitutes a powerful tool for determination of the virulence potential of V. cholerae O1 strains isolated in surveillance programs and for molecular epidemiological investigations.

Bacterial Toxins↗
PubMed1995

Serogroup conversion of Vibrio cholerae.

Vibrio cholerae serogroup O1 can be detected in the environment in a viable but nonculturable form, whereas V. cholerae non-O1 cells can be readily cultured during interepidemic periods in geographical regions where cholera is endemic. In the present study, pure cultures of V. cholerae non-O1 cells contained O1 cells when examined by immune-fluorescence microscopy. Laboratory microcosms were used to examine the outgrowth of the O1 cells in cultures of non-O1 V. cholerae. One O1 cell per 10(6) non-O1 cells could be detected by direct fluorescent-monoclonal antibody staining but only after incubation of the non-O1 culture for 48 h. Individual O1 cells were not detected in cultures incubated less than 48 h. Hybridization study, using a polymerase chain reaction (PCR) amplified fragment of the O-antigen of V. cholerae O1 as a probe, revealed the existence of a homologous gene in a microcosm sample of V. cholerae non-O1 containing serogroup-converted cells. The mechanism by which O1 cells can occur in cultures of non-O1 V. cholerae most likely resulted from spontaneous mutation of gene(s) encoding the O-somatic properties and (or) chemical, physical, or biological changes in the environment inducing expression or repression of the controlling gene(s). These findings have important implications for the epidemiology of cholera and the environmental source(s) of toxin producing V. cholerae O1.

Base Sequence↗