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Mathur P, Kapil A, Das B, Dhawan B, Dwivedi SN. Invasive beta-haemolytic streptococcal infections in a tertiary care hospital in northern India. J Med Microbiol 2002; 51:791-792. [PMID: 12358071 DOI: 10.1099/0022-1317-51-9-791] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Sarkar C, Das B, Sripathi H. Antimicrobial drug use in dermatology in a teaching hospital in western Nepal. Int J Clin Pract 2002; 56:258-60. [PMID: 12074207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
Medical audit is supposed to oversee, monitor and analyse standards of medical treatment at all levels of the healthcare delivery system. This study was undertaken to monitor the prescribing of antimicrobial drugs for patients seeking treatment in the dermatology outpatient department of the Manipal Teaching Hospital in Nepal. A total of 292 dermatology prescriptions of patients attending the dermatology OPD were collected between July 2000 and June 2001. Prescriptions for antimicrobial agents were separated from the total prescriptions collected, and evaluated. There were more female patients (58.2%) than male (41.8%) in our study; most were in the 21-40 year age group. The commonest cutaneous infections were acne (15.8%) followed by fungal infections (14.8%). Of the 292 prescriptions audited, 149 contained antimicrobial agents, constituting 36% of the total number of drugs prescribed. Of 256 antimicrobials prescribed, 63% were topical and 37% systemic; 5% were generic, 29% were from the essential drug list of Nepal, and 15% were fixed-dose combinations. Most of the patients received one or two antimicrobials, 50% of which were antibacterials and 40% antifungals. Though the selection of antimicrobial drugs used in dermatology was largely rational, anomalies were observed, and these issues were discussed with clinicians in relation to various aspects of drug use. The results indicate there is scope for improving prescribing habits. A periodic audit of drug prescribing is desirable in rationalising prescribing practice.
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Shome SC, Das HR, Das B. Spectrophotometric Determination of Thallium(III) with 3-Hydroxy-1,3-Diphenyltriazine in 70% Alcohol. Anal Chem 2002. [DOI: 10.1021/ac60243a016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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179
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Das B, Carlin R, Osteryoung RA. The ferro/ferricyanide couple in an aluminum chloride-1-methyl-3-ethylimidazolium chloride ambient-temperature molten salt. Inorg Chem 2002. [DOI: 10.1021/ic00302a011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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180
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Nádasi H, Weissflog W, Eremin A, Pelzl G, Diele S, Das B, Grande S. Ferroelectric and antiferroelectric “banana phases” of new fluorinated five-ring bent-core mesogens. ACTA ACUST UNITED AC 2002. [DOI: 10.1039/b111421b] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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181
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Das B, Sarkar C, Karanth KS. Effects of nicorandil administration on survival rate and arrhythmias during reperfusion in anesthetized rabbits. Pharmacology 2002; 63:134-41. [PMID: 11598418 DOI: 10.1159/000056124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aim was to study the effects of nicorandil (an ATP-sensitive K+ channel opener) and tolbutamide (an ATP-sensitive K+ channel blocker) on reperfusion-induced arrhythmias in pentobarbitone and ketamine anesthetized rabbits. Arrhythmias were induced by reperfusion for 20 min following a 15-min ligation of the left main coronary artery with a silk ligature. Rabbits were pretreated with nicorandil (0.47, 0.93 or 1.86 mg/kg i.v.) or tolbutamide (180 mg/kg i.p.) or vehicle (dimethylsulfoxide/saline) before the coronary artery occlusion. In the control group (n = 10), only 60% of the animals survived during reperfusion. Intravenous pretreatment with 0.47, 0.93 or 1.86 mg/kg of nicorandil increased the survival rate to 86% (n = 7), 75% (n = 8) and 86% (n = 7), respectively. Nicorandil pretreatment significantly decreased the incidence and duration of reperfusion-induced life-threatening arrhythmias and increased the number of animals that survived without developing any arrhythmia. Tolbutamide pretreatment was associated with a decreased survival rate of 50% (n = 12) and an increase in the incidence and duration of reperfusion-induced arrhythmias. Pretreatment with nicorandil may result in protection against reperfusion-induced arrhythmias and increased survival in anesthetized rabbits.
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Singh OP, Das B, Padhi MM, Tewari NS. Kushtha (skin disorders) in vedic and other religious literatures - A review. BULLETIN OF THE INDIAN INSTITUTE OF HISTORY OF MEDICINE (HYDERABAD) 2002; 32:51-5. [PMID: 15307215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
In view of the description of Medical citations; Vedic literature, Buddhist literature, Jain literature, Mahabharat, Ramayan etc. have also got significant importance. Like other diseases, the description regarding Kushtha (different skin disorders) is also available in all these treatises. These are akin to the description available in Ayurveda. From the above, it is apparent that description of different diseases mentioned in Ayurveda are also available in religious literatures.
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Sing OP, Deep V, Das B, Padhi M, Tewari N. Liver and skin disorders - a scientific review. Anc Sci Life 2002; 22:9-11. [PMID: 22557080 PMCID: PMC3330996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2002] [Accepted: 06/16/2002] [Indexed: 11/10/2022] Open
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Das B, Tao SZ, Mushnitsky R, Norin AJ. Genetic identity and differential expression of p38.5 (Haymaker) in human malignant and nonmalignant cells. Int J Cancer 2001; 94:800-6. [PMID: 11745481 DOI: 10.1002/ijc.1555] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Previous studies from our laboratory revealed a novel protein of 38.5 kD on the surface of malignant cell lines of hematopoetic origin that exhibit susceptibility to naive natural killer (NK) cell-mediated lysis. In contrast, p38.5 was not detected on the surface of NK cell-resistant carcinoma cell lines or normal cells. We now report that this protein is differentially expressed, intracellularly, in malignant cell lines of both hematopoetic and epithelial origin compared with nonmalignant cells. To characterize p38.5 further, we used a previously developed antipeptide antibody (anti-11-mer) to probe cDNA expression libraries and subsequently performed 5' extension by rapid amplification of cDNA ends (RACE). Sequence analyses of these cDNA clones reveal open reading frames (ORFs) that include the previously identified 11-mer peptide from purified, native p38.5 and that have identical sequences to a gene of unknown function on chromosome 19. Nucleotide sequence data obtained from these cDNA clones, as well as analysis of the genomic sequence, permitted design of primers for reverse transcriptase-polymerase chain reaction (RT-PCR) that resulted in a cDNA clone encoding an ORF of 361 amino acids; the clone was identical to a sequence encoded by an unpublished mRNA in GenBank. Anti-p38.5 antibody against the 11-mer peptide encoded in exon 5 and against a 25-mer peptide encoded in exon 1 both reacted with the same protein in immunoprecipitation studies, providing further evidence of identity. RT-PCR and Northern blot analyses both demonstrated p38.5 gene transcripts in normal cells, nonmalignant cell lines and malignant cell lines of epithelial as well as hematopoietic origin. Semiquantitative studies revealed a greater level of p38.5 gene transcription in malignant cell lines compared with nonmalignant cells. Immunoblot analyses of protein expression confirmed and extended the latter studies by revealing substantially greater levels of the 38.5 kD protein in whole cell extracts of malignant cell lines compared with nonmalignant cells. Quantitative differences in detection of the 38.5 kD protein and mRNA in NK susceptible- hematopoietic malignancies compared with NK resistant-carcinomas were not observed. These experiments suggest that the p38.5 gene (Haymaker) is widely expressed in human cells of different tissue origins but that elevated expression is associated with the malignant phenotype.
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Das B, Saha SP. Trigeminal neuralgia: current concepts and management. JOURNAL OF THE INDIAN MEDICAL ASSOCIATION 2001; 99:704-9. [PMID: 12022221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Trigeminal neuralgia is the most frequent cranial neuralgia, the incidence being 1 per 1,000,00 persons per year. It presents with stabbing pain often in the distribution of the mandibular and maxillary divisions of the trigeminal nerve. An accurate history of pain is important in the diagnosis of trigeminal neuralgia. A patient with tic douloureux and no neurological abnormality on clinical examination does not need diagnostic tests. The available options for management of trigeminal neuralgia are: Pharmacotherapy, destructive procedures and non-destructive procedures. The pharmacotherapy includes (i) monotherapy with one anticonvulsant, (ii) combined therapy with more than one anticonvulsant, (iii) add-on therapy with newer drugs and (iv) polytherapy with anticonvulsant + add-on drugs + antidepressants/anxiolytics. Destructive procedures include (i) non-surgical methods--injections along trigeminal pathways, percutaneous trigeminal radiofrequency thermocoagulation and (ii) surgical methods--trigeminal branch avulsion or peripheral neurectomy, avulsion of trigeminal nerve, trigeminal tractotomy, radiosurgery. Though various modalities of treatment are available for the management of trigeminal neuralgia, pharmacotherapy with carbamazepine still remains the first line of treatment. The alternative approach followed at most centres is percuatenous Gasserian rhizolysis (chemical/radiofrequency thermal) or microvascular decompression.
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Mandal P, Kapil A, Goswami K, Das B, Dwivedi SN. Uropathogenic Escherichia coli causing urinary tract infections. Indian J Med Res 2001; 114:207-11. [PMID: 12040764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
BACKGROUND & OBJECTIVES The information on the characteristics of Escherichia coli causing urinary tract infections is limited. We have characterised the urovirulence factors of Esch. coli isolated from symptomatic patients of urinary tract infections (UTI) in order to determine their pathogenic potential and the antibiotic sensitivity profile. METHODS Semi-quantitative urine culture was done on 370 symptomatic patients suffering from urinary tract infections. Phenotypic characterization of the urovirulence factors of Esch. coli was undertaken and the antibiotic susceptibility was determined. RESULTS Esch. coli was responsible for 45.5 per cent of infections. Resistance to amoxycillin, cotrimoxazole, nalidixic acid, norfloxacin and ciprofloxacin among Esch. coli isolates ranged from 70-95 per cent. Serotype O101 was found to be the commonest serotype (7/26). The virulence factors associated with uropathogenic Esch. coli were haemolysin production (5/30), presence of mannose resistant P-fimbriae (5/30), presence of mannose sensitive type 1 fimbriae (6/30) and the presence of mannose resistant F-fimbriae (2/30). Siderophores production was seen in all the isolates causing UTI. INTERPRETATION & CONCLUSION Esch. coli was found to be the commonest cause of UTI in our study population. Antibiotic resistance was high among the strains circulating which emphasises the need for judicious use of antibiotics. Certain virulence factors like haemolysin production and presence of fimbriae in the Esch. coli may be associated with the urovirulence.
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Das B, Ghosh A, Chauhan PS, Seshadri M. Population data of two minisatellite loci (D1S80 and D17S5) among five distinct ethnic groups of India. J Forensic Sci 2001; 46:1518-9. [PMID: 11714173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Das B, Sarkar C, Karanth KS. Effects of administration of nicorandil or bimakalim prior to and during ischemia or reperfusion on survival rate, ischemia/reperfusion-induced arrhythmias and infarct size in anesthetized rabbits. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2001; 364:383-96. [PMID: 11692221 DOI: 10.1007/s002100100457] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2000] [Accepted: 05/28/2001] [Indexed: 11/24/2022]
Abstract
We investigated the effects of administration of non-hypotensive doses of ATP-sensitive K+ channel (KATP) openers (nicorandil and bimakalim), and a specific mitochondrial KATP channel blocker (5-hydroxydecanoate) prior to and during coronary occlusion as well as prior to and during post-ischemic reperfusion on survival rate, ischemia-induced and reperfusion-induced arrhythmias and myocardial infarct size in anesthetized albino rabbits. The thorax was opened in the left fourth intercostal space and after pericardiotomy the heart was exposed. In Part I, occlusion of the left main coronary artery and hence, myocardial ischemia-induced arrhythmias were achieved by tightening a previously placed loose silk ligature for 30 min. In Part II, arrhythmias were induced by reperfusion following a 20-min ligation of the left main coronary artery. In Part I, early intravenous infusion of nicorandil (100 microg/kg bolus + 10 microg/kg per min) or bimakalim (3 microg/kg bolus + 0.1 microg/kg per min) just prior to and during ischemia increased survival rate (75% and 67% vs. 60% in the control group), significantly decreased the incidence and severity of life-threatening arrhythmias and significantly decreased myocardial infarct size. In Part II also, early intervention by intravenous infusion of nicorandil (100 microg/kg bolus + 10 microg/kg per min) or bimakalim (3 microg/kg bolus + 0.1 microg/kg per min) just before and during ischemia increased survival rate (86% and 75% vs. 55% in the control group), significantly decreased the incidence and severity of life-threatening arrhythmias and significantly decreased myocardial infarct size. However, late intravenous administration of nicorandil or bimakalim at the onset and during reperfusion did not increase survival rate nor confer any antiarrhythmic or cardioprotective effects. The antiarrhythmic and cardioprotective effects of both nicorandil and bimakalim were abolished by pretreating the rabbits with 5-hydroxydecanoate (5 mg/kg, i.v. bolus), a selective mitochondrial KATP channel blocker. In conclusion, intervention by intravenous administration of nicorandil and bimakalim (through the activation of mitochondrial KATP channels), increased survival rate and exhibited antiarrhythmic and cardioprotective effects during coronary occlusion and reperfusion in anesthetized rabbits when administered prior to and during coronary occlusion.
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Myers MR, Das B. Virus transmission through compromised synthetic barriers: part I--effect of unsteady driving pressures. J Biomech Eng 2001; 123:506-12. [PMID: 11601737 DOI: 10.1115/1.1394198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although synthetic membranes such as gloves, condoms, and instrument sheaths are used in environments with highly time-varying stresses, their effectiveness as barriers to virus transmission is almost always tested under static conditions. In this paper it is shown how a previously developed mathematical model can be used to transform information from static barrier tests into predictions for more realistic use conditions. Using a rate constant measured for herpes adsorption to latex in saline, and an oscillatory trans-membrane pressure representative of coitus, the amount of virus transmitted through a hole (2 microm diameter) in a condom is computed. Just beyond the exit orifice of the pore, transport is dominated by the rapidly dissipating viscous jet of virus suspension, which results in an accumulation of viruses roughly 20 pore radii from the barrier surface during each cycle. Due to virus adsorption to the barrier surfaces, the simulations reveal a gradual decrease in virus flow with increasing number of cycles, and thus a slow divergence from predictions based upon steady-state conditions. Still, over the 500 cycles simulated, steady-state predictions approximate the net number of viruses transmitted to within 25 percent error.
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Das B, Myers MR. Virus transmission through compromised synthetic barriers: part II--influence of pore geometry. J Biomech Eng 2001; 123:513-8. [PMID: 11601738 DOI: 10.1115/1.1394199] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
When stressed during normal use, synthetic barriers such as gloves and condoms can develop tears that are undetectable by the user. It is of considerable public-health importance to estimate the quantity of virus transmitted through the tear, in the event of viral contamination of the fluid medium. A mathematical model that accounts for virus adsorption to the barrier material was used to compute the quantity of virus transmitted through defects of various geometries. Slits were modeled as cylinders of elliptic cross section, and upper and lower bounds for the transmission rate of HIV and Hepatitis B virus (HBV) were calculated for barrier-use scenarios such as coitus and gripping of surgical instruments. For a 1-microm high slit, HIV transmission was found to be negligible for all likely use scenarios. HIV transmission became potentially significant for a 5-microm slit. Due to its high titer, HBV transmitted at potentially important levels even through the 1-microm slit. The dependence of the transmission rate upon pore aspect ratio was determined and found to be very strong for high-adsorption situations and near-circular pores. Numerical predictions of virus transport through a laser-drilled hole in a condom matched experimental measurements well, even when the tapered nature of the geometry is ignored.
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Schreiber AM, Das B, Huang H, Marsh-Armstrong N, Brown DD. Diverse developmental programs of Xenopus laevis metamorphosis are inhibited by a dominant negative thyroid hormone receptor. Proc Natl Acad Sci U S A 2001; 98:10739-44. [PMID: 11517345 PMCID: PMC58545 DOI: 10.1073/pnas.191361698] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2001] [Indexed: 11/18/2022] Open
Abstract
Metamorphosis of anuran tadpoles is controlled by thyroid hormone (TH). Here we demonstrate that transgenic Xenopus laevis tadpoles expressing a dominant negative form of TH receptor-alpha are resistant to a wide variety of the metamorphic changes induced by TH. This result confirms that TH receptors mediate both early and late developmental programs of metamorphosis as diverse as growth in the brain, limb buds, nose and Meckel's cartilage, remodeling of the intestine, and death and resorption of the gills and tail.
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Gulati S, Kapil A, Das B, Dwivedi SN, Mahapatra AK. Nosocomial infections due to Acinetobacter baumannii in a neurosurgery ICU. Neurol India 2001; 49:134-7. [PMID: 11447431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Invasive infections caused by Acinetobacter baumannii in a post-operative neurosurgery ICU were studied. Sixty one patients admitted during a span of 11 months were culture positive for acinetobacter species from blood and/or CSF samples. They were followed up prospectively for evidence of infection and clinical outcome. 40 cases had clinical evidence of infection due to acinetobacter species while in 21 patients, the isolation of the organism was considered a contaminant. Acinetobacter baumannii was the most common organism associated with invasive infections. Respiratory tract was found to be the most common primary source of infection in patients with bacteraemia or meningitis. The age, sex and pre-operative hospital stay were not significantly different in the two groups (p>0.05), while post-operative hospital stay and mortality was significantly higher in patients with invasive infection (p<0.05). Acinetobacter baumannii was isolated from multiple sites (p<0.05) and repeatedly from the same site (p<0.001) in a significantly higher number of patients with invasive infections. Mortality was high in the patients infected with Acinetobacter baumannii. Even amongst the infected group, the patient shaving meningitis showed a higher mortality as compared to the patients having bacteraemia.
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Das B, Meirovitch H. Optimization of solvation models for predicting the structure of surface loops in proteins. Proteins 2001; 43:303-14. [PMID: 11288180 DOI: 10.1002/prot.1041] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A novel procedure for optimizing the atomic solvation parameters (ASPs) sigma(i) developed recently for cyclic peptides is extended to surface loops in proteins. The loop is free to move, whereas the protein template is held fixed in its X-ray structure. The energy is E(tot) = E(FF)(epsilon = nr) + summation operator sigma(i)A(i), where E(FF)(epsilon = nr) is the force-field energy of the loop-loop and loop-template interactions, epsilon = nr is a distance-dependent dielectric constant, and n is an additional parameter to be optimized. A(i) is the solvent-accessible surface area of atom i. The optimal sigma(i) and n are those for which the loop structure with the global minimum of E(tot)(n, sigma(i)) becomes the experimental X-ray structure. Thus, the ASPs depend on the force field and are optimized in the protein environment, unlike commonly used ASPs such as those of Wesson and Eisenberg (Protein Sci 1992;1:227-235). The latter are based on the free energy of transfer of small molecules from the gas phase to water and have been traditionally combined with various force fields without further calibration. We found that for loops the all-atom AMBER force field performed better than OPLS and CHARMM22. Two sets of ASPs [based on AMBER (n = 2)], optimized independently for loops 64-71 and 89-97 of ribonuclease A, were similar and thus enabled the definition of a best-fit set. All these ASPs were negative (hydrophilic), including those for carbon. Very good (i.e., small) root-mean-square-deviation values from the X-ray loop structure were obtained with the three sets of ASPs, suggesting that the best-fit set would be transferable to loops in other proteins as well. The structure of loop 13-24 is relatively stretched and was insensitive to the effect of the ASPs.
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Choudhury RC, Das B, Misra S, Jagdale MB. Cytogenetic toxicity of vincristine. J Environ Pathol Toxicol Oncol 2001; 19:347-55. [PMID: 11213016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
The anticancer drugs vincristine sulphate (VCR) and cyclophosphamide (CTX) were tested for their cytogenetic effects in the bone marrow cells of Swiss mice. The end points investigated were chromosomal aberrations and mitotic index at 24 hours posttreatment and micronuclei (MN) at 30 hours posttreatment in bone marrow cells of male and female mice after a single intraperitoneal exposure. The doses tested were VCR 0.25, 0.5, and 1.0 mg/kg and CTX 40 mg/kg b.w. of mice. Significant percentages of chromosomal aberrations and significant numbers of micronuclei per thousand polychromatic erythrocytes (PCEs) that were induced were recorded from bone marrow of each of the VCR-treated groups of mice. There were no significant differences between the percentages of dividing cells in the VCR-treated group and the vehicle control groups of mice. Peculiarly, in the chromosomal aberration study, the male mice were found to be more responsive to VCR than the females, and the aberrations per hundred metaphases were found to be decreased when the dose of VCR was increased. The percentage of dividing cells was also higher with the lowest dose of VCR tested. However, there was a dose-dependent, but nonlinear, increase in MN per thousand PCEs. The results were compared with the already available fragmentary and self-contradictory data on the genotoxicity of VCR in mice and in other mammalian test systems.
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Mosteller R, Han J, Das B, Broek D. Biochemical analysis of regulation of Vav, a guanine-nucleotide exchange factor for Rho family of GTPases. Methods Enzymol 2001; 325:38-51. [PMID: 11036590 DOI: 10.1016/s0076-6879(00)25429-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Das B, Sengupta AK. Evaluation of low back pain risks in a beef skinning operation. INTERNATIONAL JOURNAL OF OCCUPATIONAL SAFETY AND ERGONOMICS 2001; 6:347-61. [PMID: 11082550 DOI: 10.1080/10803548.2000.11076460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The low back pain risks in a beef skinning operation at a high stand kill floor workstation was evaluated. The increases in compressive forces at lower back (L5/S1) between normal slump (back angle 25 degrees, measured in the sagittal plane) and severe (45 degrees ) and between normal slump and very severe (70 degrees ) bent back postures were 387 N or 28% and 616 N or 45%, respectively. The high spine load coupled with high level of repetition can have a high probability of fatigue failure in the spine structural members. Non-neutral back posture for a large portion of the total work time can be a low back pain risk factor. The videotape analysis showed that the times involved during the task performance for the bent back (more than 25 degrees ) and severe bent back (more than 45 degrees ) were 48.4 and 33.5% of the total cycle time, respectively. The upper limit from OWAS (Ovako Working Posture Analysis System) for bent back posture is 30% of the total cycle time. The bent and twisted back posture (both more than 25 degrees ) time was 10.4% compared to OWAS limit of 5%. This indicated that actions are needed in the near future to alleviate the risk of low back pain. Ergonomics redesign of the workstation was recommended for the operation.
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Abstract
BACKGROUND Photodynamic therapy (PDT) utilizes photosensitizers and light. Whereas PDT use in cancer treatment has been widely accepted, antimicrobial PDT (APDT) is still in its early stages of development. OBJECTIVES To study microbial killing in vitro using APDT. METHODS We used a combination of methylene blue and visible light, and a range of microbial species representative of those encountered on the skin in health and disease. Using standard light intensity conditions (slide projector, 25 cm distance from target, 42 mW cm(-2)) and methylene blue dye at 100 microg mL(-1), kill rates and subsequent D-values were determined against Staphylococcus aureus, S. epidermidis, Streptococcus pyogenes, Corynebacterium minutissimum, Propionibacterium acnes and Candida albicans. RESULTS D-values for these species were 72, 66, 48, 120, 30 and 660 s, respectively. The effects of light intensity on the killing of S. epidermidis showed the kill rate to be proportional to the light intensity. A high rate of cell kill was also obtained using natural sunlight. CONCLUSIONS Overall, these results indicate that APDT of the skin may represent a useful alternative to conventional antimicrobial treatment.
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Boral A, Ray S, Das B, Ghosh LK, Gupta BK. Computer supported studies on design and evaluation of solid dispersions of carbamazepine. BOLLETTINO CHIMICO FARMACEUTICO 2001; 140:28-31. [PMID: 11338773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
The main advantages of solid dispersions (the drug could be maintained in a bioavailable form, dosage reduction and cleaner manufacturing conditions) provide scope for the continued interest in field. Additionally, their use in providing a sustained or controlled release of drugs has only been tentatively examined. In the present study, Carbamazepine has been used to develop a dosage form which will provide a booster amount followed by sustained release of the drug for effective control of epileptic seizures while keeping the serum level of the drug at minimum. Enteric polymers CAP and CAT have been used to retard the release till the formulation reaches the intestine. Either individually or combined fractions of the formulations may be used in the therapy of epilepsy.
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Das B, Johnson PC, Popel AS. Computational fluid dynamic studies of leukocyte adhesion effects on non-Newtonian blood flow through microvessels. Biorheology 2000; 37:239-58. [PMID: 11026943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The study of the effect of leukocyte adhesion on blood flow in small vessels is of primary interest to understand the resistance changes in venular microcirculation. Available computational fluid dynamic studies provide information on the effect of leukocyte adhesion when blood is considered as a homogeneous Newtonian fluid. In the present work we aim to understand the effect of leukocyte adhesion on the non-Newtonian Casson fluid flow of blood in small venules; the Casson model represents the effect of red blood cell aggregation. In our model the blood vessel is considered as a circular cylinder and the leukocyte is considered as a truncated spherical protrusion in the inner side of the blood vessel. The cases of single leukocyte adhesion and leukocyte pairs in positions aligned along the same side, and opposite sides of the vessel wall are considered. The Casson fluid parameters are chosen for cat blood and human blood and comparisons are made for the effects of leukocyte adhesion in both species. Numerical simulations demonstrated that for a Casson fluid with hematocrit of 0.4 and flow rate Q = 0.072 nl/s, a single leukocyte increases flow resistance by 5% in a 32 microns diameter and 100 microns long vessel. For a smaller vessel of 18 microns, the flow resistance increases by 15%.
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