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Kundu S, Datta A, Sanyal MK, Daillant J, Luzet D, Blot C, Struth B. Growth of bimolecular films of three-tailed amphiphiles. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 73:061602. [PMID: 16906841 DOI: 10.1103/physreve.73.061602] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Revised: 03/28/2006] [Indexed: 05/11/2023]
Abstract
The three-tailed amphiphile ferric stearate molecule, which forms a bimolecular layer on water surface with molecules in the lower and upper layers in different conformations, has been studied to understand transfer and growth of bimolecular films on the surface of hydrophilic silicon substrates. This bimolecular film forms a two-dimensional lattice on water with a slightly distorted hexagonal lattice where both the in-plane and out-of-plane domain sizes are small. The film also showed larger microscopic rigidity compared to its macroscopic mechanical response. This asymmetric bimolecular layer was found to be preserved when the film is transferred on the substrates at different values of surface pressures ranging from 1 mN/m to near-collapse (55 mN/m). Both the upper and lower layers become denser and interfaces between these layers become sharper with increase in deposition pressure but the growths have different natures. The lower layer of transferred film is dense from 1 mN/m and, except for a steplike increase between 20 and 30 mN/m, changes slowly in density. The density of the upper molecular layer grows continuously with surface pressure.
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Bhakat P, Gupta A, Ayoob S, Kundu S. Investigations on arsenic(V) removal by modified calcined bauxite. Colloids Surf A Physicochem Eng Asp 2006. [DOI: 10.1016/j.colsurfa.2006.02.045] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kundu S, Datta A, Hazra S. Growth of a collapsing Langmuir monolayer. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 73:051608. [PMID: 16802947 DOI: 10.1103/physreve.73.051608] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 09/22/2005] [Indexed: 05/10/2023]
Abstract
Langmuir monolayers of stearic acid on Co ions in the aqueous subphase have been deposited at different stages of constant pressure collapse, on hydrophilic Si(001) using a modified version of the inverse Langmuir-Schaefer method of horizontal deposition. The electron density profiles (EDPs) along the depth of the deposited films, extracted from the x-ray reflectivity data, show that a monolayer to bi-molecular layer transformation takes place after collapse. The molecules in the lower monolayer have asymmetric configurations with head groups touching water and tails in air, whereas molecules in the upper layer are in symmetric configurations with tails on both sides of the heads. Atomic force microscopy images of the deposited films after collapse, however, show nearly circular islands of height more than that of the bimolecular layer observed in the EDP. As pressure increases, ridges are seen to coexist with these islands. Although the coverage of such islands and ridges is low, they play an important role in determining the growth mode. The growth of the wetting and island layers, taken together, has a striking similarity with the Stranski-Krastanow mode, observed usually for heteroepitaxial growth.
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Leong A, Kundu S, Martinez-Devesa P, Aldren C. Artificial Ear: A Training Tool for Grommet Insertion and Manual Dexterity. ORL J Otorhinolaryngol Relat Spec 2006; 68:115-7. [PMID: 16446558 DOI: 10.1159/000091214] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2005] [Accepted: 05/26/2005] [Indexed: 11/19/2022]
Abstract
Under European Working Time Directives, surgical trainees now have to attempt to gain adequate operative experience within newly-restricted working hours. Surgical skills training must therefore increasingly occur outside theatre and away from real patients, in a simulated environment. In ENT, we suggest that instruction and practice of grommet insertion may be greatly facilitated through the use of an artificial ear model, which can be assembled cheaply and quickly. Our 'ear' may also be used for manual dexterity exercises, which have the potential to be developed into validated tests of core ENT surgical skills in the future.
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Kundu S, Mandal S, Sengupta A, Dey A. A rare case of primary mediastinal non-seminomatous germ cell carcinoma in a 18 year old boy. Lung India 2006. [DOI: 10.4103/0970-2113.44389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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206
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Chattopadhyay BP, Kundu S, Mahata A, Jane Alam SK. A study to assess the respiratory impairments among the male beediworkers in unorganized sectors. Indian J Occup Environ Med 2006. [DOI: 10.4103/0019-5278.27303] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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207
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Zalev AH, Deitel W, Kundu S, Tomlinson G. Radiologic appearance of recurrent ileal Crohn disease. ACTA ACUST UNITED AC 2005; 30:665-70. [PMID: 16252144 DOI: 10.1007/s00261-005-0329-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2004] [Accepted: 02/02/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND Postoperative recurrence of Crohn disease is a common problem. It has been assumed that the radiologic patterns are similar in de novo and recurrent ileal disease, but there has been little in the literature to actually confirm this belief. METHODS We retrospectively reviewed the small bowel examinations of 105 consecutive patients with a proven diagnosis of Crohn disease: a control group of 47 patients with no prior surgery and a postoperative group of 58 patients with resections. Of the latter, 22 had ileocecal or ileocolonic resections and 36 patients had ileocecal or ileocolonic and extensive enteric resections. We examined the disease sites and compared the disease patterns in both groups. RESULTS Fifty-six of 58 (97%) postoperative patients had anastomotic recurrences with proximal extension from 3 to 25 cm, with a mean of 10.5 cm; none showed distal disease extension. Two (3%) had enteric recurrences with neoterminal ileal sparing. There were no statistically significant differences in the length of distal/terminal ileal disease and the frequency of skip lesions in de novo and recurrent disease. There were lower frequencies of mucosal thickening, ulceration/ulceronodular mucosa, sacculation, loop separation, sinuses, and masses and a higher frequency of strictures in recurrent disease than in de novo disease. There was also a lower frequency of ulceration or ulceronodular mucosa after extensive resection than after limited resection. CONCLUSION Postoperative patients with ileal Crohn disease show a marked preponderance for anastomotic recurrence with proximal disease extension. There are significant differences in disease patterns in patients with de novo and recurrent disease.
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Nigam VK, Kundu S, Ghosh P. Single-step conversion of cephalosporin-C to 7-Aminocephalosporanic acid by free and immobilized cells of Pseudomonas diminuta. Appl Biochem Biotechnol 2005; 126:13-21. [PMID: 16014995 DOI: 10.1007/s12010-005-0002-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2004] [Accepted: 03/22/2005] [Indexed: 11/25/2022]
Abstract
7-Aminocephalosporanic acid (7-ACA), the starting material for the production of a number of clinically used semisynthetic cephalosporins, is produced by deacylation of cephalosporin-C. The production of 7-ACA was studied in various modes, at the optimal conditions using free and immobilized whole cells of Pseudomonas diminuta.
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Chattopadhyay BP, Roychowdhury A, Alam J, Kundu S. Respiratory health status of the roadside school children at Kolkata. JOURNAL OF ENVIRONMENTAL SCIENCE & ENGINEERING 2005; 47:202-11. [PMID: 16841459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
School students in metro cities are often exposed to vehicle exhausts as their schools are situated mostly on the high traffic roadside. Acute exposure to automobile exhaust is associated with increased respiratory symptoms and may decrease and impair lung function in children. The lung functioning performance of the city school children was compared with rural school children where there is no pollution and automobile exhausts. In Kolkata, two schools for boys (n = 210) and two schools for girls (n = 200) and in rural area one school for boys (n = 99) and the other school for girls (n = 95) were investigated. City schools are situated on the main roadside, nearer to the traffic junction. The detail histories about health status of children, if they have any subjective feelings of health related problems during the school hours or after returning from the school, and the family histories were taken by questionnaire method. The pulmonary function tests (PFT) were carried out by Spirometric method by Spirovit-Sp-10 and Wright's Peak flow meter. The mean PFT values of the students found in the normal range. Boys were having higher values compared to the girls in both city and rural schools. Lung volumes and flow rates were significantly higher in rural students. Symptomatic changes like breathlessness, cough and other problems (sneezing, eye irritation, running nose etc.) among city schoolboys found 13%, 7% and 15% and in girls found 12%, 6% and 7% respectively. In symoptomatic students, mean PFT values were significantly lowered compared to non-symptomatic. PFT values were presented in relation to age and height. It has been found that a number of city school students are having different types of respiratory symptoms. Long-term effect of exposure into such environment may develop lung functional impairments.
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Kundu S, Datta A, Hazra S. Effect of metal ions on monolayer collapses. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:5894-900. [PMID: 15952839 DOI: 10.1021/la0505770] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A Langmuir monolayer of stearic acid on pure water and in the presence of certain divalent metal ions such as Cd and Pb at pH approximately 6.5 of the subphase water collapses at constant area, while for other divalent ions such as Mg, Co, Zn, and Mn at the same subphase pH the monolayer collapses nearly at constant pressure. Films of stearic acid with Cd, Pb, Mn, and Co in the subphase (at pH approximately 6.5) have been transferred onto hydrophilic Si(001) using a horizontal deposition technique, just after and long after collapse. Electron density profiles obtained from X-ray reflectivity analysis show that a three-molecular-layer structure starts to form just after constant area collapse, where in the lowest molecular layer, in contact with the substrate, molecules are in asymmetric configuration, i.e., both hydrocarbon tails are on the same side of the metal-bearing headgroup that touches the substrate, while the molecules above the first layer are in symmetric conformation of the tails with respect to the headgroups. Further along collapse, when the surface pressure starts to rise again with a decrease in area, more layers with molecules in the symmetric configuration are added, but the coverage is poor. On the other hand, only bimolecular layers form after constant pressure collapse, with the lower and upper layers having molecules in asymmetric and symmetric configurations, respectively, and the upper molecular layer density increases with compression of the monolayer after collapse. A "Ries mechanism" for constant area collapse and a "folding and sliding mechanism" for constant pressure collapse have been proposed.
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Iqbal N, Seshadri P, Stern L, Loh J, Kundu S, Jafar T, Samaha FF. Serum resistin is not associated with obesity or insulin resistance in humans. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2005; 9:161-5. [PMID: 16080635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
BACKGROUND Resistin has proposed link with obesity related insulin resistance and type 2 diabetes. The physiologic role of resistin in humans remains unknown. It is suggested that circulating resistin levels are not associated with obesity or insulin resistance in humans. However, the effects of weight loss on serum resistin concentration has not been studied. In order to better understand the physiologic role of resistin in human obesity, we measured the serum resistin concentration in subjects with severe obesity (before and after 6-months of dietary intervention) to test the hypothesis that serum resistin concentrations are elevated amongst individuals with severe obesity and weight loss would reduce these levels. METHODS Seventy-one obese subjects (defined as BMI > 35 kg/m2) who were randomized to low fat (LF) vs low carbohydrates (LC) diets and who completed the 6-month follow-up were studied. Their baseline demographic information was collected and serum resistin, insulin, glucose were measured at baseline and at 6-months. RESULTS Subjects in LC diet lost more weight than LF (-19.54 +/- 7.87 lbs vs -7.83 +/- 11.23 lbs., p = 0.001). Insulin sensitivity (HOMA) improved in LC group compared with LF group [-3.72 +/- 9.84 (LC) vs +1.31 +/- 7.31 (LF), p = 0.006]. Serum resistin levels did not decrease in either diet. CONCLUSIONS Our study found that despite a significant weight loss and improvement in insulin sensitivity there was no reduction in serum resistin concentration in morbidly obese men with metabolic syndrome suggesting that resistin does not play a central role in obesity related insulin resistance.
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Datta A, Kundu S, Sanyal MK, Daillant J, Luzet D, Blot C, Struth B. Dramatic enhancement of capillary wave fluctuations of a decorated water surface. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:041604. [PMID: 15903679 DOI: 10.1103/physreve.71.041604] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Revised: 12/08/2004] [Indexed: 05/02/2023]
Abstract
We have demonstrated by x-ray diffuse scattering that a bimolecular layer of a preformed three-tailed amphiphile, ferric stearate, drastically enhances capillary wave fluctuations on water surface due to a reduction in surface tension to 1 mN/m . The bimolecular layer is composed of molecules in symmetric configuration, on top of molecules in asymmetric configuration with ferric ions in contact with water. Unlike the usual Langmuir monolayers, this layer of molecules does not rupture under compression, but becomes thicker. This behavior mimics folding of a membrane on a liquid surface and is closely related to the cohesive interaction brought by the ferric ions. The low effective tension of this artificial membrane depends on the available area and reduces as the microscopic excess area increases.
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Bernstein D, Nathan R, Ledford D, Ledoux E, Pedinoff A, Crivera C, Williams J, Kundu S, Fish J, Banerji D. Ciclesonide, a new inhaled corticosteroid, significantly improves asthma-related quality of life in patients with severe, persistent asthma. J Allergy Clin Immunol 2005. [DOI: 10.1016/j.jaci.2004.12.849] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Pearlman D, Creticos P, Lampl K, Gower R, Kundu S, Fish J, Williams J, Banerji D. Once-daily ciclesonide is effective and well-tolerated in adult and adolescent patients with mild-to-moderate asthma. J Allergy Clin Immunol 2005. [DOI: 10.1016/j.jaci.2004.12.858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Shapiro G, Bensch G, Lanier R, Sher L, Lloyd M, Kundu S, Fish J, Williams J, Banerji D. Once-daily treatment with ciclesonide is effective and well-tolerated in children with persistent asthma. J Allergy Clin Immunol 2005. [DOI: 10.1016/j.jaci.2004.12.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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216
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Nayak A, Charous B, Finn A, Lumry W, Crivera C, Williams J, Kundu S, Fish J, Banerji D. A novel inhaled corticosteroid ciclesonide significantly improves quality of life in patients with mild-to-moderate asthma. J Allergy Clin Immunol 2005. [DOI: 10.1016/j.jaci.2004.12.850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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217
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Kundu S, Sharma SK, Roy S, Kundu B, Chatterjee S. Rhomboencephalosynapsis with associated supratentorial anomalies - a case report. Indian J Radiol Imaging 2005. [DOI: 10.4103/0971-3026.28738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Chowdhury PK, Halder M, Sanders L, Arnold RA, Liu Y, Armstrong DW, Kundu S, Hargrove MS, Song X, Petrich JW. The complex of apomyoglobin with the fluorescent dye coumarin 153. Photochem Photobiol 2004; 79:440-6. [PMID: 15191053 DOI: 10.1562/ra-020r.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Understanding a protein's dielectric response requires both a theoretical model and a well-defined experimental system. The former has already been proposed by Song (J. Chem. Phys. 116, 9359 [2002]). We suggest that the latter is provided by the complex of coumarin 153 (C153) with apomyoglobin (ApoMb). C153 has been exhaustively studied and has proven to be an excellent probe of the solvation dynamics of polar solvents. Myoglobin is one of the most thoroughly studied proteins. Myoglobins from a wide range of species have been subject to X-ray structural analysis and site-directed mutagenesis. Here, we demonstrate the existence of a robust C153-apomyglobin system by means of molecular dynamics simulations, equilibrium binding studies using a Job's plot and capillary electrophoresis, circular dichroism and time-resolved fluorescence. The reorganization energy of C153 bound to ApoMb is compared with that of C153 in bulk solvent using the method of Jordanides et al. (J. Phys. Chem. B 103, 7995 [1999]).
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De BK, Majumdar D, Sen S, Guru S, Kundu S. Pulmonary involvement in chronic arsenic poisoning from drinking contaminated ground-water. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2004; 52:395-400. [PMID: 15656029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
OBJECTIVES Chronic arsenic poisoning, due to ingestion of contaminated ground-water, is a major public health problem in West Bengal. It causes multiorgan damage. The present study attempts to objectively investigate the pulmonary involvement by examining the lung function. The nature of lung changes was also evaluated. MATERIAL AND METHODS One hundred and seven subjects with (cases) and 52 subjects without (controls) chronic arsenic poisoning were examined by spirometry. Forced expiratory volume-I second (FEVI), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were measured. Bronchoalveolar lavage (BAL) was performed in five cases with and five cases without pulmonary involvement. RESULTS Thirty three (30.8%) cases and four (7.6%) controls (p<0.01) had respiratory involvement. The pattern of involvement in cases was: obstructive- 20(68.9%) (including three (10%) with bronchiectasis), restrictive- 1(3.5%), mixed- 8(27.6%), malignancy- 4(12.1%) (adenocarcinoma-I, squamous cell- 2, undifferentiated- I). FEVI (69.7+/-25.9 [n=105] vs 83.7+/-15.19 [n=51], p=0.0005), FVC (77.4+/-22.7 [n=105] vs 85.6+/-18.23 [n=51], p=0.025), FEVI/FVC (73.6+/-13.38 [n=105] vs 79.1+/-18.65 [n=52], p=0.007) and PEFR (53.9+/-21.52 [n= 103] vs 67.3+/-18.36 [n=51], p=0.0002) (percent of predicted) were all reduced more in cases compared to controls. Worsening of these parameters correlated with increasing degree of arsenic toxicity. Markers of inflammation (macrophage, lactate dehydrogenase, nitric oxide) were apparently more in the BAL fluid of those with lung involvement than in those without, though the arsenic content did not differ significantly. CONCLUSION Chronic arsenic poisoning causes pulmonary involvement, predominantly obstructive, the degree of which worsens with increasing degree of arsenic toxicity. Inflammation, rather than direct toxicity, appears to be the underlying mechanism.
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Kundu S, Pal A, Ghosh SK, Mandal M, Pal T. Removal of arsenic from water using hardened paste of Portland cement. ENVIRONMENTAL TECHNOLOGY 2004; 25:301-309. [PMID: 15176745 DOI: 10.1080/09593330409355464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Portland cement has been used as a new low-cost adsorbent for the removal of arsenic from the water environment. In the batch experiments conducted at an initial concentration of 0.2 mg l(-1) of arsenate, it was found that up to 95% of arsenate could be removed. Kinetic profiles were developed for various conditions. The effect of adsorbent dose, effects of common ions such as Ca2+, Mg2+, Fe3+/Fe2+, Cl-, SO4(2-), NO3(-), PO4(3-) and the effect of pH was studied. Adsorption isotherm studies were performed and it was observed that the Freundlich isotherm was followed with a better correlation than the Langmuir isotherm. Arsenite could also be removed up to approximately 88% using the same material. A new detection method for arsenate/arsenite was developed for routine analysis of arsenic and used during the entire study.
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Halder M, Das K, Chowdhury PK, Kundu S, Hargrove MS, Petrich JW. A Comparative Femtosecond Coherence Study of the Unligated Monomeric Hemeproteins Myoglobin and Leghemoglobin. J Phys Chem B 2003. [DOI: 10.1021/jp034828u] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Chowdhury PK, Kundu S, Halder M, Das K, Hargrove MS, Petrich JW. Effects of Distal Pocket Mutations on the Geminate Recombination of NO with Leghemoglobin on the Picosecond Time Scale. J Phys Chem B 2003. [DOI: 10.1021/jp030106r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Szefler S, Herron J, Lloyd M, Rohatagi S, Williams J, Kundu S, Banerji D. High doses of the novel inhaled steroid ciclesonide have no effect on HPA-axis function in patients with moderate-to-severe persistent asthma. J Allergy Clin Immunol 2003. [DOI: 10.1016/s0091-6749(03)80749-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ramana S, Biswas AK, Kundu S, Saha JK, Yadava RBR. Effect of distillery effluent on seed germination in some vegetable crops. BIORESOURCE TECHNOLOGY 2002; 82:273-275. [PMID: 11991076 DOI: 10.1016/s0960-8524(01)00184-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A laboratory experiment was conducted to study the effect of different concentrations (0%, 5%, 10%, 15%, 20%, 25%, 50%, 75% and 100%) of distillery effluent (raw spent wash) on seed germination (%), speed of germination, peak value and germination value in some vegetable crops: tomato, chilli, bottle gourd, cucumber and onion. The distillery effluent did not show any inhibitory effect on seed germination at low concentration except in tomato, but in onion the germination was significantly higher (84%) at 10% concentration as against 63% in the control. Irrespective of the crop species, at highest concentrations (75% and 100%), complete failure of germination was observed. The speed of germination, peak value and germination value also followed a similar trend. We found that a concentration of 5% was critical for seed germination in tomato and bottle gourd, and 25% in the rest of the crops. Based on the tolerance to distillery effluent, the crops studied have been arranged in the following order: cucumber > chilli > onion > bottle gourd > tomato. We conclude that the effect of the distillery effluent is crop-specific and due care should be taken before using the distillery effluent for pre-sowing irrigation purposes.
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Phuapradit W, Shah NH, Lou Y, Kundu S, Infeld MH. Critical processing factors affecting rheological behavior of a wax based formulation. Eur J Pharm Biopharm 2002; 53:175-9. [PMID: 11880000 DOI: 10.1016/s0939-6411(01)00224-7] [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: 11/22/2022]
Abstract
The use of a wax-based vehicle is one approach to stabilize a drug which is susceptible to hydrolysis and/or oxidation. The drug used in the study, as a microfine powder, is dispersed in the wax mixture and encapsulated in a soft gelatin capsule. To ensure reproducibility of drug content uniformity and encapsulability of the soft gelatin capsule dosage form, optimal viscosity and lot to lot uniformity of the viscosity of the suspension are required. The objective of the study was to identify the critical processing factors which could affect the rheological behavior of the wax based vehicle. Rheological behavior of the vehicle at temperatures ranging from 15 to 90 degrees C was evaluated using a CSL Rheometer equipped with parallel plates and a shear rate sweep mode, unless otherwise specified. Viscosity vs. temperature profiles of the vehicle were determined using the same conditions at different cooling rates ranging from 1.3 to 20 degrees C per min. Three distinct regions of phase transition of the wax mixture can be seen in the Arrhenius plot: (i) a sol region at temperatures above 50 degrees C, (ii) a transition of gel to sol at temperatures ranging from 30 to 45 degrees C, and (iii) a gel region at temperatures below 30 degrees C. The vehicle in a sol region behaved as a Newtonian fluid, indicating minimal interactions between the hydrocarbon chains of the vehicle. The vehicle in a gel region behaved thixotropic in nature, as indicated by a hysteresis loop. The shear rate had a more pronounced effect on the area of thixotropy than the shear time. The cooling rate had a pronounced effect on the resultant viscosity. At the same applied shear rate, the vehicle which was cooled at a faster rate, may cause a recrystallization of the wax mixture in different crystalline forms, resulting in a higher viscosity than the vehicle cooled at a slower rate. This effect was more pronounced when the shear was applied at a lower rate. The results of this study indicate that shear rate and cooling rate are the critical processing factors in controlling the viscosity of the final product and must be well controlled in the manufacturing procedure.
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Roy B, Chowdhury A, Kundu S, Santra A, Dey B, Chakraborty M, Majumder PP. Increased risk of antituberculosis drug-induced hepatotoxicity in individuals with glutathione S-transferase M1 'null' mutation. J Gastroenterol Hepatol 2001; 16:1033-7. [PMID: 11595069 DOI: 10.1046/j.1440-1746.2001.02585.x] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Pathogenesis and genetic factors influencing predisposition to antituberculosis drug (ATD)-induced hepatotoxicity are not clear. Polymorphism at the genetic locus of a drug and xenobiotic compound metabolizing enzyme, N-acetyltransferase type 2 (NAT2), is reported to be associated with the excess generation of toxic reactive metabolites. Polymorphisms at the glutathione S-transferase (GST) loci (GSTM1 and GSTT1) are involved in the detoxification of these toxic metabolites in the human body to a lesser extent. We have examined whether polymorphisms at these loci are associated with the risk of ATD-induced hepatotoxicity. METHODS In this case-control study, 33 pulmonary tuberculosis patients with ATD-induced hepatotoxicity and 33 pulmonary tuberculosis patients receiving ATD drugs without any evidence of hepatotoxicity were considered as cases and controls, respectively. Point mutations at NAT2 and homozygous 'null' mutations at GSTM1 and GSTT1 genes were looked into genomic DNA, isolated from peripheral blood mononuclear cells by using polymerase chain reaction (PCR). RESULTS The frequency of homozygous 'null' mutation at the GSTM1 gene was significantly higher among cases (n = 17, 52%) than controls (n = 8, 24%) (P < 0.05, relative risk 2.13, 95% CI: 1.25-3.10). Frequencies of mutations at GSTT1 and NAT2 genes did not differ significantly between cases and controls. CONCLUSION Homozygous 'null' mutation at the GSTM1 gene might predispose an individual to ATD-induced hepatotoxicity.
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Kundu S, Eynon-Lewis NJ, Radcliffe GJ. Extensive metastatic renal cell carcinoma presenting as facial nerve palsy. J Laryngol Otol 2001; 115:488-90. [PMID: 11429075 DOI: 10.1258/0022215011908009] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Metastatic lesions of the parotid gland are well described in the literature. Metastatic spread to the parotid from renal cell carcinoma is rare. We present the only reported case of facial nerve palsy caused by a metastasis to the parotid from a renal cell carcinoma.
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Chowdhury A, Santra A, Kundu S, Mukherjee A, Pandit A, Chaudhuri S, Dhali GK. Induction of oxidative stress in antitubercular drug-induced hepatotoxicity. Indian J Gastroenterol 2001; 20:97-100. [PMID: 11400818] [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: 12/11/2022]
Abstract
BACKGROUND AND AIM Oxidative stress could play a role in the pathogenesis of antitubercular drug (ATD)-induced hepatotoxicity. We therefore studied the plasma level of reduced glutathione (GSH) and malondialdehyde (MDA) in patients with ATD-induced hepatotoxicity (cases), ATD-treated controls (disease controls) and in healthy volunteers. METHODS This study was carried out in a case-control design. Twenty-one cases, 21 age- and sex-matched disease controls, and 10 healthy volunteers were enrolled. Plasma levels of GSH and MDA were measured. RESULTS Plasma levels of GSH (median [range] 11.5 [6.2-21.2] mmol/dL) and MDA (1390 [560-2310] nmol/dL) of cases were significantly different (p<0.01) from GSH (18.4 [10.5-24.4]) and MDA (290 [240-550]) of disease controls. Further, plasma GSH and MDA levels of both the ATD-treated groups were different from those in healthy controls. CONCLUSION Lower levels of plasma GSH and higher levels of MDA may be due to oxidative stress resulting from ATD therapy.
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Kundu S, Bandyopadhyay D, Thakur AR. Sequence-based structural signatures of genome evolution. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 2001; 38:104-6. [PMID: 11563320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Among the multitude of methods available for the study of origin and evolution of various life forms on Earth, the phylogenetic approach, i.e. the delineation of natural genetic relatedness amongst different groups of organisms, has been of particular interest to evolutionary biologists. An approach towards analysing phylogeny is the comparison of genome sequences of extant organisms by a variety of computational techniques. These studies rely mostly on the similarity or dissimilarity in global character of the genome in terms of sequence, without any consideration to its structure. In this work, we report a potentially new methodology towards elucidation of molecular phylogeny. The approach considers a structural parameter of the genome, namely its flexibility, and uses it to compare the small subunit ribosomal ribonucleic acid (SSU rRNA) gene from a cross-section of species. We find that the flexibility pattern of the genome is strikingly similar in organisms that are closer in evolutionary distance than the ones that are separated. This method of comparison thus might be utilised in constructing phylogenetic trees from flexibility patterns derived from nucleotide sequence.
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Das T, Kundu S, Mazumdar AK, Mukhopadhyay SC. Studies on central nervous system function in diabetes mellitus. JOURNAL OF THE INDIAN MEDICAL ASSOCIATION 2001; 99:84, 86-7, 89. [PMID: 11482808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Fifty-seven insulin dependent (IDDM) and non-insulin dependent (NIDDM) diabetic patients and 25 controls were studied. Patients with history of strokes, hypoglycaemia, hearing impairment, diabetic retinopathy, etc, were excluded. Clinical examination of central nervous system (CNS) and computerised tomography scan of brain were absolutely normal in all cases. Neuroelectrophysiological tests done were the visual evoked potential (VEP), brainstem auditory evoked response (BAER) and somatosensory evoked potential (SEP). The mean VEP latency was significantly raised in both NIDDM and IDDM compared with controls. The mean BAER and SEP latencies were both significantly raised in NIDDM but not in IDDM. The percentage of cases with abnormally raised CNS latencies were as follows: In NIDDM, VEP-16.7%, BAER-50% and SEP-26.7%; in IDDM, VEP-11.1%, BAER-14.8% and SEP-18.5%. Thus, subclinical CNS dysfunction is common in diabetes mellitus particularly in NIDDM and this can be reliably detected by measuring the CNS latencies, specially VEP.
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Kundu S, Bhattacharya D, Thakur AR, Majumdar R. Nucleosomal positioning and genetic divergence study based on DNA flexibility map. J Biomol Struct Dyn 2001; 18:527-33. [PMID: 11245248 DOI: 10.1080/07391102.2001.10506685] [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: 10/28/2022]
Abstract
Based on worm like chain model, DNA structural parameters--tilt, roll and rise, derived from crystallographic database have been used to determine the flexibility of DNA that regulates the nucleosomal translational positioning. Theoretically derived data has been compared to the experimental values available in loshikhes and Trifonov's database. The methodology has been extended to determine the flexibility of 18S rRNA genome in eukarya, where yeast shows a distinct difference when compared with mammals like human, mouse and rabbit.
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Schooley RT, Spino C, Kuritzkes D, Walker BD, Valentine FA, Hirsch MS, Cooney E, Friedland G, Kundu S, Merigan TC, McElrath MJ, Collier A, Plaeger S, Mitsuyasu R, Kahn J, Haslett P, Uherova P, deGruttola V, Chiu S, Zhang B, Jones G, Bell D, Ketter N, Twadell T, Chernoff D, Rosandich M. Two double-blinded, randomized, comparative trials of 4 human immunodeficiency virus type 1 (HIV-1) envelope vaccines in HIV-1-infected individuals across a spectrum of disease severity: AIDS Clinical Trials Groups 209 and 214. J Infect Dis 2000; 182:1357-64. [PMID: 11023459 DOI: 10.1086/315860] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2000] [Revised: 06/20/2000] [Indexed: 11/03/2022] Open
Abstract
The potential role of human immunodeficiency virus type 1 (HIV-1)-specific immune responses in controlling viral replication in vivo has stimulated interest in enhancing virus-specific immunity by vaccinating infected individuals with HIV-1 or its components. These studies were undertaken to define patient populations most likely to respond to vaccination, with the induction of novel HIV-1-specific cellular immune responses, and to compare the safety and immunogenicity of several candidate recombinant HIV-1 envelope vaccines and adjuvants. New lymphoproliferative responses (LPRs) developed in <30% of vaccine recipients. LPRs were elicited primarily in study participants with a CD4 cell count >350 cells/mm(3) and were usually strain restricted. Responders tended to be more likely than nonresponders to have an undetectable level of HIV-1 RNA at baseline (P=.067). Induction of new cellular immune responses by HIV-1 envelope vaccines is a function of the immunologic stage of disease and baseline plasma HIV-1 RNA level and exhibits considerable vaccine strain specificity.
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Chakrabarti R, Kundu S, Kumar S, Chakrabarti R. Vitamin A as an enzyme that catalyzes the reduction of MTT to formazan by vitamin C. J Cell Biochem 2000; 80:133-8. [PMID: 11029760 DOI: 10.1002/1097-4644(20010101)80:1<133::aid-jcb120>3.0.co;2-t] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The tetrazolium salt 3(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) is reduced to formazan by the succinate dehydrogenase system of active mitochondria, and hence, specifically used to assay for the viable cells, such as measurement of cell proliferation, cytotoxicity, and cell number. However, in the present study we have shown that some component specifically present in M199 but not in RPMI 1640 media can reduce MTT to formazan in the absence of a living system. Further study revealed that ascorbic acid reduced MTT to formazan, which was profoundly increased by a very small amount of retinol, whereas retinol alone had no effect. Oxidation of ascorbic acid by H(2)O(2) destroyed its ability to reduce MTT. The rate of MTT reduction was directly proportional to the concentration of MTT in the absence of retinol, but approached a zero-order state beyond a certain concentration of MTT in the presence of retinol. Furthermore, retinol remained unchanged after the completion of the reaction. Taken together, these results showed that retinol acts as a reductase that catalyzes the reduction of MTT to formazan using ascorbic acid as the cosubstrate (electron donor).
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Abstract
Plasma cell polyps of the vocal fold (plasma cell granulomas) are rare inflammatory polyps of the larynx. They should be included in the clinical and histological differential diagnosis of laryngeal polyps. Histologically they are polyclonal aggregates of plasma cells. It is essential to distinguish them from monoclonal, neoplastic plasma cell proliferations. The treatment of choice is surgical resection, although radiotherapy, laser ablation, antibiotics and steroids have been used successfully. We present a case of plasma cell granuloma presenting as a vocal fold polyp, treated surgically.
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Sundd M, Kundu S, Jagannadham MV. Alcohol-induced conformational transitions in ervatamin C. An alpha-helix to beta-sheet switchover. JOURNAL OF PROTEIN CHEMISTRY 2000; 19:169-76. [PMID: 10981808 DOI: 10.1023/a:1007010818108] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Alcohol-induced conformational transitions of erv C, a highly stable cysteine protease, were followed by CD, fluorescence, and activity. At acidic pH, the addition of different alcohols caused two types of conformational transitions. Increasing the concentration of nonfluorinated alkyl alcohols induced a conformational switch from alpha-helix to beta-sheet. Under these conditions, the protein lost its proteolytic activity and tertiary structure. The switch was a sudden one, observed in 50% methanol, 45% ethanol, and 40% propanol. Under similar conditions of pH and concentration, however, glycerol and TFE enhanced the alpha-helicity of the protein. Methanol-induced denaturation was observed to occur in two stages; the first is the beta-sheet state stabilized at low alcohol concentrations, and the other is the beta-sheet state with enhanced ellipticity stabilized at high alcohol concentrations. This beta-sheet conformation can be attained from the native as well as 6 M GuHCl-denatured state by addition of methanol and exhibits properties different from the native or unfolded state. This state shows loss of tertiary structure and activity, enhanced nonnative secondary structure, noncooperative temperature unfolding, and higher stability toward denaturants as compared to the native state, which are characteristic of the molten globule-like state or O-state, and thus this state may be functioning as an intermediate in the folding pathway of erv C.
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Michelson AD, Furman MI, Goldschmidt-Clermont P, Mascelli MA, Hendrix C, Coleman L, Hamlington J, Barnard MR, Kickler T, Christie DJ, Kundu S, Bray PF. Platelet GP IIIa Pl(A) polymorphisms display different sensitivities to agonists. Circulation 2000; 101:1013-8. [PMID: 10704169 DOI: 10.1161/01.cir.101.9.1013] [Citation(s) in RCA: 239] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Both inherited predisposition and platelet hyperreactivity have been associated with ischemic coronary events, but mechanisms that support genetic differences among platelets from different subjects are generally lacking. Associations between the platelet Pl(A2) polymorphism of GP IIIa and coronary syndromes raise the question as to whether this inherited variation may contribute to platelet hyperreactivity. METHODS AND RESULTS In this study, we characterized functional parameters in platelets from healthy donors with the Pl(A) (HPA-1) polymorphism, a Leu (Pl(A1)) to Pro (Pl(A2)) substitution at position 33 of the GP IIIa subunit of the platelet GP IIb/IIIa receptor (integrin alpha(IIb)beta(3)). We studied 56 normal donors (20 Pl(A1,A1), 20 Pl(A1,A2), and 16 Pl(A2,A2)). Compared with Pl(A1,A1) platelets, Pl(A2)-positive platelets showed a gene dosage effect for significantly greater surface-expressed P-selectin, GP IIb/IIIa-bound fibrinogen, and activated GP IIb/IIIa in response to low-dose ADP. Surface expression of GP IIb/IIIa was similar in resting platelets of all 3 genotypes but was significantly greater on Pl(A2,A2) platelets after ADP stimulation (P=0.003 versus Pl(A1,A1); P=0.03 versus Pl(A1,A2)). Pl(A1,A2) platelets were more sensitive to inhibition of aggregation by pharmacologically relevant concentrations of aspirin and abciximab. CONCLUSIONS Pl(A2)-positive platelets displayed a lower threshold for activation, and platelets heterozygous for Pl(A) alleles showed increased sensitivity to 2 antiplatelet drugs. These in vitro platelet studies may have relevance for in vivo thrombotic conditions.
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Kundu S, Sundd M, Jagannadham MV. Purification and characterization of a stable cysteine protease ervatamin B, with two disulfide bridges, from the latex of Ervatamia coronaria. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2000; 48:171-179. [PMID: 10691612 DOI: 10.1021/jf990661j] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Latex of the medicinal plant Ervatamia coronaria was found to contain at least three cysteine proteases with high proteolytic activity, called ervatamins. One of these proteases, named ervatamin B, has been purified to homogeneity using ion-exchange chromatography and crystallization. The molecular mass of the enzyme was estimated to be 26 000 Da by SDS-PAGE and gel filtration. The extinction coefficient (epsilon(1%)(280 nm)) of the enzyme was 20.5 with 7 tryptophan and 10 tyrosine residues per molecule. The enzyme hydrolyzed denatured natural substrates such as casein, azoalbumin, and azocasein with a high specific activity. In addition, it showed amidolytic activity toward N-succinyl-alanine-alanine-alanine-p-nitroanilide with an apparent K(m) and K(cat) of 6.6 +/- 0.5 mM and 1.87 x 10(2) s(-)(1), respectively. The pH optima was 6.0-6.5 with azocasein as substrate and 7.0-7.5 with azoalbumin as substrate. The temperature optimum was around 50-55 degrees C. The enzyme was basic with an isoelectric point of 9.35 and had no carbohydrate content. Both the proteolytic and amidolytic activity of the enzyme was strongly inhibited by thiol-specific inhibitors. Interestingly, the enzyme had only two disulfide bridges versus three as in most plant cysteine proteases of the papain superfamily. The enzyme was relatively stable toward pH, denaturants, temperature, and organic solvents. Polyclonal antibodies raised against the pure enzyme gave a single precipitin line in Ouchterlony's double immunodiffusion and typical color in ELISA. Other related proteases do not cross-react with the antisera to ervatamin B showing that the enzyme is immunologically distinct. The N-terminal sequence showed conserved amino acid residues and considerable similarity to typical plant cysteine proteases.
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Katzenstein DA, Kundu S, Spritzler J, Smoller BR, Haszlett P, Valentine F, Merigan TC. Delayed-type hypersensitivity to recombinant HIV envelope glycoprotein (rgp160) after immunization with homologous antigen. J Acquir Immune Defic Syndr 1999; 22:341-7. [PMID: 10634195 DOI: 10.1097/00126334-199912010-00004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Delayed-type hypersensitivity (DTH) responses to intradermal recombinant HIV envelope glycoprotein (rgp160) may assess cell-mediated immune responses to HIV envelope. In three studies, DTH and lymphocyte proliferation responses to rgp160 were obtained in a total of 106 HIV-seropositive subjects with CD4+ counts >400 cells/mm3. Several subjects participated in more than one study. Before immunization, DTH responses were seen in 5 of 56 (9%) of HIV-infected study subjects. After immunization with an alum-adjuvanted experimental rgp160 vaccine, DTH responses were seen in 46 of 52 (89%). Using in vitro lymphocyte proliferation activity (LPA) to rgp160 as an indication of cellular immune response, skin testing has a sensitivity of 0.75 (95% confidence Interval [CI], 0.59-0.88) and a specificity of 0.84 (95% CI, 0.72-0.92). Biopsy samples of skin that had tested positive confirmed the presence of a DTH reaction with a predominance of CD4+ T cells in the perivascular, inflammatory infiltrate. Skin testing before and after immunization with candidate AIDS vaccines could provide a simple method in the field to assess new cell mediated immune responses.
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von Siebenthal K, Beran J, Wolf M, Keel M, Dietz V, Kundu S, Bucher HU. Cyclical fluctuations in blood pressure, heart rate and cerebral blood volume in preterm infants. Brain Dev 1999; 21:529-34. [PMID: 10598053 DOI: 10.1016/s0387-7604(99)00062-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Many recently published papers describe cyclical changes of cerebral circulatory variables, mainly in cerebral blood flow velocity (CBFV) performed with Doppler sonography. In this paper we focus on another important variable of cerebral circulation: on cerebral blood volume (CBV) measured by near infrared spectrophotometry (NIRS). In a retrospective analysis of NIRS measurements in 20 preterm infants (median 27 3/7 weeks of gestation), the dominating frequencies and prevalence of cyclical changes of CBV and its possible correlation with peripheral circulatory variables (mean arterial pressure and heart rate) was examined. In 19 out of the 20 infants cyclical changes of CBV were found within a frequency range of 2-4.7 cycles/min which is comparable to the results of the Doppler studies describing fluctuations in CBFV. A dominating frequency of heart rate (HR), was found only in 12 out of 20 infants, and it was with 2.1-3.8 cycles/min in a similar range compared to CBV. In mean arterial blood pressure (MABP), however we detected cycles with longer periods every 1-2.5 min in 14 out of 20 infants. There was a significant coherence between MABP/CBV and HR/CBV. The area under the coherence curve, however, was significantly larger between MABP and CBV as compared to HR and CBV (P = 0.0007, Wilcoxon signed-rank test).
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Kundu S, Sundd M, Jagannadham MV. Structural characterization of a highly stable cysteine protease ervatamin C. Biochem Biophys Res Commun 1999; 264:635-42. [PMID: 10543984 DOI: 10.1006/bbrc.1999.1550] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ervatamin C, a novel cysteine protease, belongs to alpha + beta class of proteins, probably with two domains, and retains both secondary and tertiary structures along with biological activity over a wide range of pH (2-12). Under neutral conditions, GuHCl and temperature-induced unfolding was cooperative with high transition midpoints and shows no structural changes in the presence of urea reflecting a remarkable stability. The fluorescence emission maximum at 350 nm suffers a blue shift of 4-5 nm upon lowering the pH and a red shift of 5 nm under denatured conditions. Unfolding transition curves at pH 2.0 are non-coincidental indicating the presence of intermediates in the unfolding pathway. At extremely low pH, the enzyme loses all the tertiary structure and proteolytic activity but retains a predominant secondary structure and a strong binding to ANS. GuHCl-induced unfolding of the enzyme in this intermediate state is noncooperative and indicates sequential unfolding of the domains.
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Bhattacharyya D, Kundu S, Thakur AR, Majumdar R. Sequence directed flexibility of DNA and the role of cross-strand hydrogen bonds. J Biomol Struct Dyn 1999; 17:289-300. [PMID: 10563579 DOI: 10.1080/07391102.1999.10508362] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Persistence length and torsional rigidity for different B-DNA sequences have been calculated by analysing crystal structure database. The values of these parameters for mixed sequence DNA are in good agreement with those estimated by others. Persistence lengths for the homopolymeric sequences, namely poly(dA).poly(dT) and poly(dG).poly(dC), are significantly large compared to those of others as expected from the inability of these sequences to form nucleosome under normal conditions. The heteropolymeric sequences poly(dA-dC).poly(dG-dT) and poly(dG-dC).poly(dG-dC), on the other hand, have smaller persistence lengths. This implies larger flexibility of the d(AC).d(GT), d(CA).d(TG), d(GC).d(GC) and d(CG).d(CG) doublets, some of which constitute the genetic disease forming triplet repeats d(CTG).d(CAG) and d(CGG).d(CCG). Thus it is expected that these triplet repeat sequences are also flexible and wrap around the histone octamer efficiently. Persistence length calculations also indicate larger flexibility for these triplet repeat sequences. Furthermore, our computations reveal that the rigidity of a given DNA sequence is controlled by its ability to form cross-strand bifurcated hydrogen bonds between the successive base pairs. Molecular orbital calculations suggest that these hydrogen bonds are generally extended with bond lengths around 3A.
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Löfdahl CG, Reiss TF, Leff JA, Israel E, Noonan MJ, Finn AF, Seidenberg BC, Capizzi T, Kundu S, Godard P. Randomised, placebo controlled trial of effect of a leukotriene receptor antagonist, montelukast, on tapering inhaled corticosteroids in asthmatic patients. BMJ (CLINICAL RESEARCH ED.) 1999; 319:87-90. [PMID: 10398629 PMCID: PMC28156 DOI: 10.1136/bmj.319.7202.87] [Citation(s) in RCA: 191] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To determine the ability of montelukast, a leukotriene receptor antagonist, to allow tapering of inhaled corticosteroids in clinically stable asthmatic patients. DESIGN Double blind, randomised, placebo controlled, parallel group study. After a single blind placebo run in period, during which (at most) two inhaled corticosteroids dose decreases occurred, qualifying, clinically stable patients were allocated randomly to receive montelukast (10 mg tablet) or matching placebo once daily at bedtime for up to 12 weeks. SETTING 23 academic asthma centres in United States, Canada, and Europe. PARTICIPANTS 226 clinically stable patients with chronic asthma receiving high doses of inhaled corticosteroids (113 randomised to montelukast and 113 to placebo). INTERVENTIONS Every 2 weeks, the inhaled corticosteroids dose was tapered, maintained, or increased (rescue) based on a standardised clinical score. MAIN OUTCOME MEASURES Last tolerated dose of inhaled corticosteroids. RESULTS Compared with placebo, montelukast allowed significant (P=0. 046) reduction in the inhaled corticosteroid dose (montelukast 47% v placebo 30%; least square mean difference 17.6%, 95% confidence interval 0.3 to 34.8). Fewer patients on montelukast (18 (16%) v 34 (30%) placebo, P=0.01) required discontinuation because of failed rescue. CONCLUSIONS Montelukast reduces the need for inhaled corticosteroids among patients requiring moderate to high doses of corticosteroid to maintain asthma control.
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Kundu S, Herman SJ, Larhs A, Rappaport DC, Weisbrod GL, Maurer J, Chamberlain D, Winton T. Correlation of chest radiographic findings with biopsy-proven acute lung rejection. J Thorac Imaging 1999; 14:178-84. [PMID: 10404503 DOI: 10.1097/00005382-199907000-00004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The purpose of this study was to determine the chest radiographic findings of acute rejection and the accuracy of chest radiography in making this diagnosis in patients undergoing lung transplantation. For each of 100 transbronchial biopsies performed on 25 lung transplant recipients (single lung in three, double lung in 22), chest radiographs obtained within 24 hours before the biopsy were reviewed retrospectively without knowledge of clinical or biopsy information. Transbronchial biopsy revealed 42 instances of acute rejection in 17 patients and 58 instances of no acute rejection (normal, n = 43; other processes, n = 15). All pulmonary parenchymal radiographic abnormalities were assessed. Acute rejection was associated with the presence of middle or lower lung reticular interstitial or airspace disease in 21 lungs (sensitivity = 0.50 [21/42]). This pattern was seen in 18 lungs without acute rejection (specificity = 0.69 [40/58]). There was no difference in the appearance of the lungs between grades 1 and 2 acute rejection. Normal lungs were noted in 20 instances of acute rejection (48%). The authors conclude that chest radiograph findings are abnormal in about 50% of instances of biopsy-proven acute rejection. Because the appearance of acute rejection is similar to that of other conditions, the diagnosis cannot be made accurately by chest radiography.
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Bal-Tembe S, Kundu S, Roy K, Hiremath C, Gole G, de Souza EP, Vijaya Kumar E, Gates D, Pillmoor J. Activity of the ilicicolins against plant pathogenic fungi. ACTA ACUST UNITED AC 1999. [DOI: 10.1002/(sici)1096-9063(199906)55:6<645::aid-ps992>3.0.co;2-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kundu S, Murphy J, Towers M, Leung CS. Computed tomographic demonstration of very-low-density pulmonary nodules in metastatic gastric carcinoma: case report. Can Assoc Radiol J 1999; 50:198-201. [PMID: 10405654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
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Chakrabarti C, Biswas S, Kundu S, Sundd M, Jagannadham MV, Dattagupta JK. Crystallization and preliminary X-ray analysis of ervatamin B and C, two thiol proteases from Ervatamia coronaria. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 1999; 55:1074-5. [PMID: 10216310 DOI: 10.1107/s0907444999002917] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Two highly stable cysteine proteases, ervatamin B (ERV-B) and ervatamin C (ERV-C), purified from the latex of the medicinal plant E. coronaria have been crystallized at room temperature. Crystals of ERV-B and ERV-C diffract to 2.5 and 2.6 A, respectively. The space group is P212121 for the crystals of both proteases with unit-cell parameters a = 47.5, b = 58.8 and c = 68.8 A, and a = 43.8, b = 82.6 and c = 133.1 A, respectively. A self-rotation function for ERV-C indicates a twofold non-crystallographic symmetry relating the two molecules in the asymmetric unit.
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Kottke-Marchant K, Powers JB, Brooks L, Kundu S, Christie DJ. The effect of antiplatelet drugs, heparin, and preanalytical variables on platelet function detected by the platelet function analyzer (PFA-100). Clin Appl Thromb Hemost 1999; 5:122-30. [PMID: 10725993 DOI: 10.1177/107602969900500209] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The platelet function analyzer (PFA)-100 is a newly developed instrument that provides a rapid, in vitro, quantitative measurement of platelet adhesion and aggregation in whole blood flowing through a small aperture under high shear conditions. Thirty patients undergoing percutaneous transluminal coronary angioplasty (PTCA) and ten normal individuals were included in this study. In vitro and in vivo studies were conducted to discern the effect of combinations of antiplatelet drugs (aspirin, ticlopidine, abciximab) and heparin on the performance of the device as well as the effects of preanalytical variables, such as method of sample collection and ex vivo anticoagulants. Studies were also conducted examining the effect of aperture size (standard 150 microns vs. smaller 120 microns) on the ability of the device to detect the effect of antiplatelet drugs. There was no difference in mean PFA-100 closure time with citrate versus PPACK anticoagulants or with venipuncture vs. sheath sampling. Closure times did not vary with heparin administration. Closure times were slightly longer for patients taking aspirin plus ticlopidine compared to aspirin alone (p = NS). In contrast adenosine disphosphate (ADP) induced platelet aggregation was significantly less in patients that took aspirin plus ticlopidine vs. aspirin alone (p = .0005). In vitro, there was a dose-dependent increase in closure time for both aperture sizes with increasing abciximab concentration. Although both cartridges showed infinite closure times at an abciximab concentration of 2.25 micrograms/mL, there was a slight benefit to using the 120 microns aperture cartridges at abciximab concentrations of 1.75 to 2.0 micrograms/mL. In ten patients who were followed during abciximab therapy to assess the effect of aperture size, the PFA-100 was able to detect in vivo platelet inhibition by abciximab, but detection of recovery from abciximab-induced platelet dysfunction was slightly better for the PFA-100 with the 120 microns aperture compared to the standard 150 microns aperture collagen/ADP cartridge.
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Abstract
A theoretical investigation of the denaturation characteristics of a supercoiled DNA has been presented employing a Metropolis Monte Carlo algorithm to examine the overall melting profiles of a supercoiled plasmid as the temperature is varied. We show that in contrast to a previously presented algorithm, this much simpler method is sufficient to explain almost all the overall denaturation characteristics and it also correctly calculates the detailed denaturation probabilities of each base pair at various degrees of supercoiling. We also present for the first time a theoretical investigation of the alkaline denaturation of a supercoiled plasmid. Although one can qualitatively reproduce the denaturation profiles using the present Monte Carlo algorithm, the agreement with experiment is not as good as in the case of thermal denaturation. The possible sources of discrepancy between theory and experiment have been discussed.
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Ganguli SN, Steinhardt MI, Kundu S. Hepatopulmonary syndrome associated with sarcoidosis of the liver: case report. Can Assoc Radiol J 1998; 49:411-4. [PMID: 9879271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
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