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Biomedical subjects

R Mazumder

Publications and source records attributed to R Mazumder.

At least 19 recordsLinked to original sources
PubMed2006

Antidiarrhoeal evaluation of Aegle Marmelos (Correa) Linn. root extract.

A study was undertaken to evaluate the in vitro and in vivo antidiarrhoeal potential of chloroform extract of the root of Aegle marmelos (Correa) Linn. The in vitro activity was determined by agar dilution and disc diffusion techniques. The extract was studied in vivo in rats. Of the 35 tested pathogenic diarrhoea causing strains, the extract was found to be mostly active against the strains of Vibrio cholerae, followed by Escherichia coli and Shigella spp. The in vitro activity was found to be comparable to that of ciprofloxacin. Further, Aegle marmelos root extract (AMRE) treated animals showed significant inhibitory activity against castor oil-induced diarrhoea. The results so obtained thus established the efficacy of AMRE as an effective antidiarrhoeal agent.

Aegle↗
PubMed2005

Effect of Mesua ferrea Linn. flower extract on Salmonella.

Based on its traditional uses in folk medicine, the whole flower extract of Mesua ferrea Linn. was tested for its in vitro antimicrobial efficacy against five different strains of Salmonella spp. All the strains were found to be highly sensitive to the extract, MIC of the extract against each organism being 50 microg/ml. The extract was tested in vitro for its mode of antibacterial activity against S. Typhimurium NCTC 74 and it was found to be bactericidal in action. In vivo studies of this extract offered significant protection to Swiss albino mice at doses approximately 2 and 4 mg/mouse when challenged with 50 median lethal dose of S. Typhimurium NCTC 74. Further, the extract caused statistically significant reduction in viable count of the strain in liver, spleen and heart blood of challenged mice.

Animals↗
PubMed2003

High efficiency degradation of tetrahydrofuran (THF) using a membrane bioreactor: identification of THF-degrading cultures of Pseudonocardia sp. strain M1 and Rhodococcus ruber isolate M2.

A mixed microbial culture capable of growing aerobically on tetrahydrofuran (THF) as a sole carbon and energy source was used as the inoculum in a 10 l working volume membrane bioreactor. Following start-up, the reactor was operated in batch mode for 24 h and then switched to continuous feed with 100% biomass recycle. On average, greater than 96% of THF fed to the reactor was removed during the 8-month study. THF loading rates ranged from 0.62 to 9.07 g l(-1) day(-1) with a hydraulic retention time of 24 h. THF concentrations as high as 800 mg/l were tolerated by the culture. Biomass production averaged 0.28 kg total suspended solids/kg chemical oxygen demand removed, i.e., comparable to a conventional wastewater treatment process. Periodic batch wasting resulted in a solids retention time of 7-14 days. Reactor biomass typically ranged from 4 to 10 g/l volatile suspended solids and the effluent contained no solids. Pure THF-degrading cultures were isolated from the mixed culture based on morphological characteristics, Gram-staining and THF degradation. Based on 16S rDNA analysis the isolates were identified as Pseudonocardia sp. M1 and Rhodococcus ruber M2.

Bioreactors↗
PubMed2001

Trifluoperazine: a broad spectrum bactericide especially active on staphylococci and vibrios.

Trifluoperazine showed some significant antimicrobial activity when tested against 293 strains from two Gram-positive and eight Gram-negative genera. Minimum inhibitory concentrations of the drug were measured using an agar dilution technique. Forty six of 55 strains of Staphylococcus aureus were inhibited by 10-50 microg/ml of trifluoperazine. This drug also inhibited strains of Shigella spp., Vibrio cholerae and V. parahaemolyticus at a concentration of 10-100 microg/ml. Other bacteria including Pseudomonas spp. were moderately sensitive to trifluoperazine. In the in vivo studies this compound offered significant protection to Swiss albino mice at a concentration of 30 microg/mouse (P<0.001) when challenged with 50 median lethal dose of Salmonella typhimurium NCTC 74.

Animals↗
PubMed2001

Comparisons of gene colinearity in genomes using GeneOrder2.0.

Comparative genomics is enhanced by data mining the rapidly expanding DNA sequence databases. Because of the immense amount of data, computational tools and methods are needed to augment traditional manual visualizations and manipulations of these data. GeneOrder2.0, a Java-based interactive software programme, organizes genome sequence data into tabular and graphical visualizations of the extent of colinearity of genes between any two chromosome genomes of < or =250 kilobases. Both GenBank and proprietary data can be analyzed with this tool.

Computational Biology↗
PubMed2001

GeneOrder: comparing the order of genes in small genomes.

MOTIVATION: The recent rapid rise in the availability of whole genome DNA sequence data has led to bottlenecks in their complete analysis. Specifically, there is a need for software tools that will allow mining of gene and putative gene data at a whole genome level. These new tools will complement the current set already in use for studying specific aspects of individual genes and putative genes in detail. A key software challenge is to make them user-friendly, without losing their flexibility and capability for use in research. RESULTS: The creation of GeneOrder-a web-based interactive, computational tool-allows researchers to compare the order of genes in two genomes. It has been tested on full genome sequence data for viruses, mitochondria and chloroplasts that were obtained from the NCBI GenBank database. It is accessible at http://www.bif.atcc.org/GENEOrder/index.html. GeneOrder prepares the comparison in table form, listing the order of similar genes. Hyperlinks are provided from this output; these lead to the 'Protein Coding Regions' in the NCBI database.

Animals↗
PubMed2000

Low-substrate regulated microaerophilic behavior as a stress response of aquatic and soil bacteria.

Low-substrate regulated microaerophilic behavior (LSRMB) was observed in 10-54% of the bacteria isolated from several fresh-water lakes or ponds, subsurface soils, activated sludge, and Antarctic dry valley soils. Five Pseudomonas and two Bacillus type species showed LSRMB. A subsurface Pseudomonas jessenii strain was used as a model to show the metabolic interaction between substrate and oxygen concentrations, cell band movement, and the appearance of unique stress lipids and proteins. When the oxygen in the P. jessenii culture medium was increased from 11% to 100% saturation under atmospheric condition, the concentration of 17:0 cyclopropane fatty acid, a stress indicator, increased five-fold, and four unique proteins were also detected. This stress response occurred only in low-substrate media. It is our hypothesis that LSRMB is a common but under-appreciated trait of many aquatic and soil bacteria.

Bacterial Physiological Phenomena↗
PubMed1999

Determining chemotactic responses by two subsurface microaerophiles using a simplified capillary assay method.

A simplified capillary chemotaxis assay utilizing a hypodermic needle, syringe, and disposable pipette tip was developed to measure bacterial tactic responses. The method was applied to two strains of subsurface microaerophilic bacteria. This method was more convenient than the Adler method and required less practice. Isolate VT10 was a strain of Pseudomonas syringae, which was isolated from the shallow subsurface. It was chemotactically attracted toward dextrose, glycerol, and phenol, which could be used as sole carbon sources, and toward maltose, which could not be used. Isolate MR100 was phylogenetically related to Pseudomonas mendocina and was isolated from the deep subsurface. It showed no tactic response to these compounds, although, it could use dextrose, maltose, and glycerol as carbon sources. The chemotaxis results obtained by the new method were verified by using the swarm plate assay technique. The simplified technique may be useful for routine chemotactic testing.

Bacteriological Techniques↗
PubMed1992

Foot and mouth disease in gayals (Bos gaurus frontalis) in Calcutta Zoo.

A brief description is given of an outbreak of foot and mouth disease in gayals (Bos gaurus frontalis) which occurred in Calcutta Zoo in October 1990. Four of the five affected animals died within ten days of onset of the disease. The disease did not spread to other animals in the Zoo.

Animals↗
PubMed1990

A comparison of mebeverine with high-fibre dietary advice and mebeverine plus ispaghula in the treatment of irritable bowel syndrome: an open, prospectively randomised, parallel group study.

OBJECTIVE To compare the efficacy and acceptability of mebeverine and high-fibre dietary advice versus mebeverine and ispaghula in fixed combination in the treatment of irritable bowel syndrome in adults. DESIGN Open, prospectively randomised, parallel group comparison of mebeverine/dietary advice and mebeverine/ispaghula during an eight-week study period. SETTING General practices in the UK. PATIENTS One hundred and eleven patients with irritable bowel syndrome diagnosed by symptom profile or negative investigations between the ages of 18 and 75 years were entered. All patients had a history of abdominal pain occurring at least once a week for a period of three months or more. INTERVENTION Dosage was 135 mg of mebeverine hydrochloride, three times daily before meals, together with advice on high-fibre dietary intake, or 135 mg of mebeverine hydrochloride plus 3.5 g of ispaghula husk twice or three times daily before meals. MEASUREMENTS AND RESULTS Details of abdominal pain severity and frequency, bowel frequency and stool consistency were recorded by means of clinicians' assessments and patient diaries. Pre-treatment assessments revealed no significant differences between the two groups with respect to any of the parameters. Both treatment groups demonstrated highly significant improvements in the numbers of pain attacks and their severity; no statistically significant differences between the two groups were demonstrated. Five patients in the mebeverine/dietary advice group reported five concurrent effects and nine patients in the mebeverine/ispaghula group reported 13 concurrent effects. All of the mebeverine/dietary advice group found their treatment acceptable but up to 28% of the mebeverine/ispaghula group found their treatment unpalatable. CONCLUSION Both treatments are effective in the treatment of irritable bowel syndrome in adults. The fixed combination of mebeverine/ispaghula, however, was found to be unpalatable by up to 28% of the patients in that group. There does not, therefore, appear to be any advantage in using fixed combination therapy in this condition.

Adolescent↗
PubMed1985

Brain 5-hydroxytryptamine and plasma testosterone in L-tryptophan treated rats.

Loading of L-tryptophan for 7 and 21 days increased brain 5-hydroxytryptamine (5-HT) level which was associated with decreased plasma testosterone level. Human chorionic gonadotropin (HCG) administration in L-tryptophan treated rats for 21 days increased the plasma testosterone level in spite of increased brain 5-HT level. These results suggest that brain 5-HT exerts an inhibitory influence on testicular steroidogenesis by modulating the gonadotropin-releasing-factor (GnRH) release and thence pituitary gonadotropins.

Animals↗
PubMed1985

Effect of intraventricular injection of 5,6-dihydroxytryptamine on spermatogenesis and plasma testosterone levels in the rat.

Quantitative evaluation of spermatogenesis at stage VII of the cycle of the seminiferous epithelium and radioimmunoassay of plasma testosterone were performed in adult Wistar rats after intraventricular injection of 5,6-dihydroxytryptamine (5,6-DHT). The rats were killed 2, 10 and 21 days after injection. Brain 5-hydroxytryptamine (5-HT) and plasma testosterone levels were found to be significantly lower in all rats treated with 5,6-DHT. A significant reduction in step 7 spermatid count was also observed after 10 and 21 days. Supplementation with human chorionic gonadotrophin for 21 days in rats injected with 5,6-DHT partially prevented the step 7 spermatid degeneration and increased testosterone levels without producing any effect on brain concentrations of 5-HT. These results suggest that changes in testicular steroidogenesis and spermatogenesis are secondary to pituitary gonadotrophin release which, in turn, is under the influence of brain 5-HT neurones.

5,6-Dihydroxytryptamine↗
PubMed1978

An inhibitor which interferes with the enzymatic aminoacylation of tRNA.

Inactive, frozen and thawed cytoplasmic extracts of 3T3 and SV-101 (3T3 transformed by SV-40 virus) cells contain an inhibitor which blocks the poly(U)-directed incorporation of [14C]phenylalanine into polypeptides, catalyzed by active extracts of these cells. This inhibition is not reversed by adding increased amounts of poly(U). Furthermore, little or no inhibitory activity is observed when poly(U) translation is assayed using precharged [14C]Phe-tRNA. These results suggest that the observed inhibition is not due to the degradation of poly(U) by a nuclease. The inhibitor appears to act primarily at the level of tRNA charging since the synthesis of both Phe-tRNA and Lys-tRNA is impaired in its presence. Evidence is presented which indicates that the inhibitory activity is not due to a high molecular weight protein or nucleic acid. However, the inhibitor appears to be adsorbed to a macromolecule. The inhibitory activity is completely destroyed by ashing.

Amino Acyl-tRNA Synthetases↗