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Pandya B, Ghosh SK, Chude G, Rajmohan MV, Narang R. Retroperitoneal Castleman's disease mimicking soft tissue tumour. Indian J Surg 2007; 69:153-4. [PMID: 23132970 DOI: 10.1007/s12262-007-0009-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2004] [Accepted: 08/27/2007] [Indexed: 11/28/2022] Open
Abstract
Castleman's disease is a type of non-neoplastic lymphoproliferative disease having lymph nodal hyperplasia. It has two distinct microscopic types: hyaline-vascular type and plasma cell type. Clinically, it may present either as a solitary mass, most commonly in the mediastinum, or as a multicentric form whose features are generalized lymph-adenopathy, splenomegaly and involvement of other organs like the lungs and kidneys. Here we report a case of isolated retroperitoneal Castleman's disease, which presented as a lump in the iliac fossa in a young female. A clinico-radio-logical diagnosis of retroperitoneal soft tissue tumour was made and the patient underwent complete surgical excision. The exact diagnosis was only obtained at histopathology and there is no evidence of recurrence at six months follow-up.
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Chatterjee A, Ghosh SK. A new monopartite begomovirus isolated from Hibiscus cannabinus L. in India. Arch Virol 2007; 152:2113-8. [PMID: 17619113 DOI: 10.1007/s00705-007-1029-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Accepted: 06/08/2007] [Indexed: 10/23/2022]
Abstract
Yellow vein mosaic disease of mesta is whitefly-transmitted and found in endemic form in different parts of India, causing great economic losses. Full-length DNA-A of a begomovirus infecting mesta was cloned and sequenced. The genome was homologous to the DNA-A of monopartite begomoviruses originating from the Old World, with six conserved open reading frames. The complete nucleotide sequence of the DNA-A molecule of the present isolate was 2728 nucleotides in length, having the highest sequence identity (83.5%) with an Indian begomovirus causing cotton leaf curl disease. It thus belongs to a novel geminivirus species, and the name Mesta yellow vein mosaic virus is proposed.
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Das S, Karim S, Datta Ray C, Maiti AK, Ghosh SK, Chaudhury K. Peripheral blood lymphocyte subpopulations in patients with cervical cancer. Int J Gynaecol Obstet 2007; 98:143-6. [PMID: 17572423 DOI: 10.1016/j.ijgo.2007.04.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Revised: 04/05/2007] [Accepted: 04/11/2007] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Impairment of cell-mediated immunity in carcinoma of the cervix (CA CX) and cervical intraepithelial neoplasia (CIN) are reported. Contradictory reports exist on lymphocyte subpopulations associated with this disease. The present study aims to quantitatively analyze peripheral blood lymphocytes subsets in patients with CA CX and CIN. METHOD Systemic T lymphocyte subsets, CD19+, CD16+ and CD56+ cells in 58 CA CX and 10 CIN patients were studied. The lymphocyte phenotypes were quantified by monoclonal antibodies (anti-CD4, CD8, CD16, CD19 and CD56). RESULT Significant decrease in CD4+ cell population was observed in CA CX and CIN patients as compared to controls (P< or =0.05). CD4+/CD8+ ratio was observed to be less in CIN patients (P< or =0.001). Other lymphocyte subpopulations appeared to be comparable between the groups. CONCLUSION Results indicate immunological abnormalities in invasive CA CX and CIN patients. Study on a larger patient population may provide a biomarker for early detection of this disease.
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Ghosh SK, Mukhopadhyay P. Bayesian Analysis of Quality Adjusted Lifetime (QAL) Data. JOURNAL OF STATISTICAL THEORY AND PRACTICE 2007. [DOI: 10.1080/15598608.2007.10411836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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330
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Ghosh SK, Ganapathy R, Krishnaswamy R, Bellare J, Raghunathan VA, Sood AK. Structure of mesh phases in a cationic surfactant system with strongly bound counterions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:3606-14. [PMID: 17319705 DOI: 10.1021/la0631466] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We report the observation of an intermediate mesh phase with rhombohedral symmetry, corresponding to the space group Rm, in a mixed surfactant system formed by the cationic surfactant cetyltrimethylammonium bromide (CTAB) and the organic salt 3-sodium-2-hydroxy naphthoate (SHN). It occurs between a random mesh phase (L(alpha)(D)) and a lamellar phase (L(alpha)) at low temperatures; at higher temperatures, the (L(alpha)(D)) phase transforms continuously into the (L(alpha)) phase with an increasing surfactant concentration (phi(s)). To separate the effects of salt and phi(s) on the phase behavior, the ternary system consisting of cetyltrimethylammonium 3-hydroxy-naphthalene-2-carboxylate (CTAHN), sodium bromide (NaBr), and water was studied. The intermediate mesh phase is found in this system at high NaBr concentrations. The micellar aggregates, both in the intermediate and random mesh phases, are found to be made up of a two-dimensional network of rod-like segments, with three rods meeting at each node. The average mesh size increases with phi(s), and the transition from the random mesh phase to the intermediate phase is found to occur when it is approximately 1.5 times the lamellar periodicity. The intermediate mesh phase is absent in the equimolar dodecyltrimethylammonium bromide (DTAB)-SHN system, indicating the role of the surfactant chain length in the formation of this phase. This system exhibits a random mesh phase over a very wide range of water content, with the average mesh size decreasing upon an increasing phi(s), contrary to the trend seen in the CTAB-SHN system.
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Pandolfino JE, Ghosh SK, Zhang Q, Han A, Kahrilas PJ. Upper sphincter function during transient lower oesophageal sphincter relaxation (tLOSR); it is mainly about microburps. Neurogastroenterol Motil 2007; 19:203-10. [PMID: 17300290 DOI: 10.1111/j.1365-2982.2006.00882.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Transient lower oesophageal sphincter relaxations (tLOSRs) are both a dominant mechanism of reflux and an element of the belch reflex. This study aimed to analyse the interplay between reflux and upper oesophageal sphincter (UOS) activity during meal-induced tLOSRs. Fifteen normal subjects were studied with a solid-state high-resolution manometry assembly positioned to record from the hypopharynx to the stomach and a catheter pH electrode 5 cm above the LOS. Subjects ate a 1000-calorie high-fat meal and were monitored for 120 min in a sitting posture. The relationship among tLOSRs, common cavities, pressure changes within the oesophagus and UOS contractile activity were analysed. A total of 218 tLOSRs occurred among the 15 subjects. The majority (79%) were coupled with UOS relaxation and 84% (145/173) of these occurred in association with a common cavity. Upper oesophageal sphincter relaxation was usually preceded by a pressure change in the oesophagus; however, some relaxations (16%) occurred without a discernable increase in pressure or before the pressure increase began. Acid reflux did not appear to play a role in determining UOS response to tLOSRs. The majority of post-prandial tLOSRs were associated with brief periods of UOS relaxation, likely permissive of gas venting (microburps). Intraoesophageal pressure changes likely modulate this UOS response; however, an anticipatory characteristic was evident in some subjects. Whether or not GORD patients with extra-oesophageal symptoms exhibit an exaggeration of the UOS relaxation response during reflux is yet to be determined.
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Park JW, Genton MG, Ghosh SK. Censored time series analysis with autoregressive moving average models. CAN J STAT 2007. [DOI: 10.1002/cjs.5550350113] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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333
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Ghosh SK, Chaudhuri J, Gachhui R, Mandal A, Ghosh S. Effect of mercury and organomercurials on cellular glucose utilization: a study using resting mercury-resistant yeast cells. J Appl Microbiol 2007; 102:375-83. [PMID: 17241342 DOI: 10.1111/j.1365-2672.2006.03100.x] [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] [Indexed: 11/28/2022]
Abstract
AIMS Mercury compounds are highly toxic to all types of living cells. Isolated yeast strains of Rhodotorula rubra showed high and low resistance pattern towards mercury and organomercurial compounds. To investigate the basis of differential sensitivity of these two types of strains, glucose utilization was measured in the presence of mercury compounds. METHODS AND RESULTS Glucose utilization process remained unaffected in resting cells of highly Hg(2+)-resistant strain in the presence of HgCl(2) but not in the presence of phenylmercuric acetate and thimerosal. However, HgCl(2) significantly affected glucose utilization in the case of low-resistant cells. The Hg-retaining ability of the cell wall of highly Hg(2+)-resistant yeast strain was greater than that of the weakly Hg(2+)-resistant strain. The spheroplast-bound Hg(2+) was also significantly less in the highly Hg(2+)-resistant strain than in the weakly Hg(2+)-resistant strain. CONCLUSIONS Glucose uptake machinery was not affected in the presence of toxic metal ions in the case of high-resistant strains. But in the case of low Hg(2+)-resistant strain, glucose transport system may be affected either by inactivation of sensor proteins containing -SH group associated with glucose uptake. SIGNIFICANCE AND IMPACT OF THE STUDY Cell wall of mercury-resistant yeast cells may play an important role in heavy metal bioremediation process.
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Fuentes M, Song HR, Ghosh SK, Holland DM, Davis JM. Spatial association between speciated fine particles and mortality. Biometrics 2007; 62:855-63. [PMID: 16984329 DOI: 10.1111/j.1541-0420.2006.00526.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Particulate matter (PM) has been linked to a range of serious cardiovascular and respiratory health problems, including premature mortality. The main objective of our research is to quantify uncertainties about the impacts of fine PM exposure on mortality. We develop a multivariate spatial regression model for the estimation of the risk of mortality associated with fine PM and its components across all counties in the conterminous United States. We characterize different sources of uncertainty in the data and model the spatial structure of the mortality data and the speciated fine PM. We consider a flexible Bayesian hierarchical model for a space-time series of counts (mortality) by constructing a likelihood-based version of a generalized Poisson regression model that combines methods for point-level misaligned data and change of support regression. Our results seem to suggest an increase by a factor of two in the risk of mortality due to fine particles with respect to coarse particles. Our study also shows that in the Western United States, the nitrate and crustal components of the speciated fine PM seem to have more impact on mortality than the other components. On the other hand, in the Eastern United States, sulfate and ammonium explain most of the fine PM effect.
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Alegria AE, Cruz-Martinez N, Ghosh SK, Garcia C, Arce R. Photosensitized reduction and DNA covalent binding of aziridinylquinones. J Photochem Photobiol A Chem 2007. [DOI: 10.1016/j.jphotochem.2006.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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336
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Doctor PB, Bhagia LJ, Derasari AY, Vyas JB, Amin RJ, Ghosh SK. A preliminary study on gram-negative bacteria (GNB) and their endotoxins in a gin house in India. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2006; 3:707-12. [PMID: 17133691 DOI: 10.1080/15459620601015844] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The presence of byssinosis, an occupational disease found among cotton mill workers, has been well documented in different parts of the world. The disease develops due to exposure to environmental cotton dust. Evidence suggests that the causative agent for the disease is gram-negative bacteria (GNB) and their endotoxins present on the cotton fibers. An investigation was carried out in a gin house in western India. Environmental dust samples were collected by vertical elutriator (VE). Airborne dust concentrations were very high in the working environment: 2.11 mg/m3 in ginning and 0.95 mg/m3 in the press department (p < 0.05), which was higher than the threshold limit value collected by VE (0.2 mg/m3), and higher than the permissible exposure limit for respirable dust (0.5 mg/m3 for nontextile industries using cotton). In the office control site, the dust concentration was 0.31 mg/m3. The Occupational Safety and Health Administration's cotton dust standard permissible exposure limit for respirable dust is 0.2 mg/m3 in yarn manufacturing, 0.75 mg/m3 in slashing and weaving, and 0.5 mg/m3 in nontextile industries using cotton. These samples also showed high concentrations of airborne endotoxin (p < 0.001) in ginning and pressing (2.77 and 1.52 micro g/m3) compared with the office control site (0.009 micro g/m3 measured by Limulus amoebocyte lysate technique). Total enumeration of airborne GNB was carried out qualitatively by the petri plate exposure method and quantitatively by an Andersen 6-stage viable sampler and VE. GNB were recovered in quite high numbers. Among all the GNB, Enterobacter agglomerans were the dominant bacterial flora. Results indicate that gin workers are occupationally exposed to airborne GNB and endotoxins, and require masks.
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Richards SL, Apperson CS, Ghosh SK, Cheshire HM, Zeichner BC. Spatial analysis of Aedes albopictus (Diptera: Culicidae) oviposition in suburban neighborhoods of a Piedmont community in North Carolina. JOURNAL OF MEDICAL ENTOMOLOGY 2006; 43:976-89. [PMID: 17017237 DOI: 10.1603/0022-2585(2006)43[976:saoaad]2.0.co;2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Temporal and spatial distribution of egg-laying by Aedes albopictus (Skuse) (Diptera: Culicidae) was investigated in suburban neighborhoods in Raleigh, NC, by using oviposition traps (ovitraps) at fixed sampling stations during the 2002 and 2003 mosquito seasons. Variations in the phenology of oviposition between the two mosquito seasons resulted from differences in the patterns and amounts of rainfall early in the season. Aerial images of each study neighborhood were digitized, and the proportions of specific types of land cover within buffer zones encompassing ovitraps were estimated. Retrospective analyses showed that in some neighborhoods, oviposition intensity was significantly associated with specific types of land cover. However, in general, it seemed that gravid Ae. albopictus searched throughout the landscape for water-filled containers in which to lay eggs. Peridomestic surveys were carried out concurrently with ovitrap collections to estimate production of Ae. albopictus pupae in discarded water-filled containers and the abundance of females in vegetation that made up the resting habitat. Results of linear regression analyses indicated that the mean standing crop of pupae (total and per container) per residence was not a significant predictor of mean egg densities in ovitraps. However, the mean standing crop of adult females was a significant but weak predictor variable, because the magnitude and sign of regression coefficients varied between neighborhoods. Linear spatial regression analyses revealed that oviposition intensity was not spatially dependent on pupal standing crop or the numbers of pupae-positive containers distributed peridomestically. However, a weak spatial dependence on the standing crop of adult females was found in some neighborhoods. Based on spherical variogram models, kriging was carried out to predict the spatial patterns of oviposition in suburban neighborhoods. Focal areas of high and low oviposition intensity were evident in most neighborhoods; however, the spatial patterns of oviposition changed between mosquito seasons. Kriging predictions were evaluated, using cross-validation, by systematically removing each data point from our data set and predicting the removed point by using the remaining points. The root mean square (standardized) error values of best fitting variogram models approximated 1, and plots of standardized PRESS residuals showed no distinct pattern for most neighborhoods, indicating that predictions of the spatial distribution of oviposition intensity were valid. Spherical variogram models are a satisfactory method for describing the spatial distribution of Ae. albopictus oviposition, and kriging can be a useful technique for predicting oviposition intensity at locations that have not been sampled.
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Ghosh SK, Ghosh S, Gachhui R, Mandal A. Mercury and organomercurial resistance in Rhodotorula rubra: activation of glutathione reductase. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2006; 77:351-8. [PMID: 17033861 DOI: 10.1007/s00128-006-1073-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Accepted: 07/25/2006] [Indexed: 05/12/2023]
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339
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Richards SL, Apperson CS, Ghosh SK, Cheshire HM, Zeichner BC. Spatial analysis of Aedes albopictus (Diptera: Culicidae) oviposition in suburban neighborhoods of a Piedmont community in North Carolina. JOURNAL OF MEDICAL ENTOMOLOGY 2006. [PMID: 17017237 DOI: 10.1093/jmedent/43.5.976] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Temporal and spatial distribution of egg-laying by Aedes albopictus (Skuse) (Diptera: Culicidae) was investigated in suburban neighborhoods in Raleigh, NC, by using oviposition traps (ovitraps) at fixed sampling stations during the 2002 and 2003 mosquito seasons. Variations in the phenology of oviposition between the two mosquito seasons resulted from differences in the patterns and amounts of rainfall early in the season. Aerial images of each study neighborhood were digitized, and the proportions of specific types of land cover within buffer zones encompassing ovitraps were estimated. Retrospective analyses showed that in some neighborhoods, oviposition intensity was significantly associated with specific types of land cover. However, in general, it seemed that gravid Ae. albopictus searched throughout the landscape for water-filled containers in which to lay eggs. Peridomestic surveys were carried out concurrently with ovitrap collections to estimate production of Ae. albopictus pupae in discarded water-filled containers and the abundance of females in vegetation that made up the resting habitat. Results of linear regression analyses indicated that the mean standing crop of pupae (total and per container) per residence was not a significant predictor of mean egg densities in ovitraps. However, the mean standing crop of adult females was a significant but weak predictor variable, because the magnitude and sign of regression coefficients varied between neighborhoods. Linear spatial regression analyses revealed that oviposition intensity was not spatially dependent on pupal standing crop or the numbers of pupae-positive containers distributed peridomestically. However, a weak spatial dependence on the standing crop of adult females was found in some neighborhoods. Based on spherical variogram models, kriging was carried out to predict the spatial patterns of oviposition in suburban neighborhoods. Focal areas of high and low oviposition intensity were evident in most neighborhoods; however, the spatial patterns of oviposition changed between mosquito seasons. Kriging predictions were evaluated, using cross-validation, by systematically removing each data point from our data set and predicting the removed point by using the remaining points. The root mean square (standardized) error values of best fitting variogram models approximated 1, and plots of standardized PRESS residuals showed no distinct pattern for most neighborhoods, indicating that predictions of the spatial distribution of oviposition intensity were valid. Spherical variogram models are a satisfactory method for describing the spatial distribution of Ae. albopictus oviposition, and kriging can be a useful technique for predicting oviposition intensity at locations that have not been sampled.
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340
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Mahendran B, Ghosh SK, Kundu SC. Molecular phylogeny of silk-producing insects based on 16S ribosomal RNA and cytochrome oxidase subunit I genes. J Genet 2006; 85:31-8. [PMID: 16809837 DOI: 10.1007/bf02728967] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We have examined the molecular-phylogenetic relationships between nonmulberry and mulberry silkworm species that belong to the families Saturniidae, Bombycidae and Lasiocampidae using 16S ribosomal RNA (16S rRNA) and cytochrome oxidase subunit I (coxI) gene sequences. Aligned nucleotide sequences of 16S rRNA and coxI from 14 silk-producing species were used for construction of phylogenetic trees by maximum likelihood and maximum parsimony methods. The tree topology on the basis of 16S rRNA supports monophyly for members of Saturniidae and Bombycidae. Weighted parsimony analysis weighted towards transversions relative to transitions (ts, tv4) for coxI resulted in more robust bootstrap support over unweighted parsimony and favours the 16S rRNA tree topology. Combined analysis reflected clear biogeographic pattern, and agrees with morphological and cytological data.
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341
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Schlosser PM, Borghoff SJ, Coldham NG, David JA, Ghosh SK. Physiologically-based pharmacokinetic modeling of genistein in rats, Part I: Model development. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2006; 26:483-500. [PMID: 16573635 DOI: 10.1111/j.1539-6924.2006.00743.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Genistein is a phytoestrogen-a plant-derived compound that binds to and activates the estrogen receptor-occurring at high levels in soy beans and food products, leading to widespread human exposure. The numerous scientific publications available describing genistein's dosimetry, mechanisms of action, and identified or putative health effects in both experimental animals and humans make it ideal for examination as an example of endocrine-active compound (EAC). We developed a physiologically-based pharmacokinetic (PBPK) model to quantify the internal, target-tissue dosimetry of genistein in adult rats. Complexities of the model include enterohepatic circulation, binding of both genistein and its conjugates to plasma proteins, and the multiple compartments used to describe transport through the bile duct and gastrointestinal tract. Other aspects of the model are simple perfusion-limited transport to the tissue groups and first-order rates of metabolism, uptake, and excretion. We describe here the model structure and initial calibration of the model by fitting to a large data set for Wistar rats. The model structure can be readily extrapolated to describe genistein dosimetry in humans or modified to describe the dosimetry of other phytoestrogens and phenolic EACs. The model does a fair job of capturing the pharmacokinetics. Although it does not describe the interindividual variability and we have not identified a single set of parameters that provide a good fit to the data for both oral and intravenous exposures, we believe it provides a good initial attempt at PBPK modeling for genistein, which can serve as a template for other phytoestrogens and in the design of future experiments and research that can be used to fill data gaps and better estimate model parameters.
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342
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Ghosh SK, Bharadwaj PK. Infinite Chains of Quasi-Planar Hexameric Water Clusters Stabilized in a Metal-Organic Framework Built from CoII and Pyrazine- 2,3,5,6-tetracarboxylic Acid. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200500670] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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343
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Ghosh SK, Bharadwaj PK. Octameric Water Clusters of Staircase Structure Present in a Metal-Organic Framework Built from Helical Lanthanide Coordination Polymers. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200500735] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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344
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Krishnaswamy R, Ghosh SK, Lakshmanan S, Raghunathan VA, Sood AK. Phase behavior of concentrated aqueous solutions of cetyltrimethylammonium bromide (CTAB) and sodium hydroxy naphthoate (SHN). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:10439-43. [PMID: 16262304 DOI: 10.1021/la051781q] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We have characterized the phase behavior of mixtures of the cationic surfactant cetyltrimethylammonium bromide (CTAB) and the organic salt 3-sodium-2-hydroxy naphthoate (SHN) over a wide range of surfactant concentrations using polarizing optical microscopy and X-ray diffraction. A variety of liquid crystalline phases, such as hexagonal, lamellar with and without curvature defects, and nematic, are observed in these mixtures. At high temperatures the curvature defects in the lamellar phase are annealed gradually on decreasing the water content. However, at lower temperatures these two lamellar structures are separated by an intermediate phase, where the bilayer defects appear to order into a lattice. The ternary phase diagram shows a high degree of symmetry about the line corresponding to equimolar CTAB/SHN composition, as in the case of mixtures of cationic and anionic surfactants.
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345
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Huggins W, Ghosh SK, Nanda K, Wollenzien P. Internucleotide movements during formation of 16 S rRNA-rRNA photocrosslinks and their connection to the 30 S subunit conformational dynamics. J Mol Biol 2005; 354:358-74. [PMID: 16242153 DOI: 10.1016/j.jmb.2005.09.060] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Revised: 09/14/2005] [Accepted: 09/19/2005] [Indexed: 10/25/2022]
Abstract
UV light-induced RNA photocrosslinks are formed at a limited number of specific sites in the Escherichia coli and in other eubacterial 16 S rRNAs. To determine if unusually favorable internucleotide geometries could explain the restricted crosslinking patterns, parameters describing the internucleotide geometries were calculated from the Thermus thermophilus 30 S subunit X-ray structure and compared to crosslinking frequencies. Significant structural adjustments between the nucleotide pairs usually are needed for crosslinking. Correlations between the crosslinking frequencies and the geometrical parameters indicate that nucleotide pairs closer to the orientation needed for photoreaction have higher crosslinking frequencies. These data are consistent with transient conformational changes during crosslink formation in which the arrangements needed for photochemical reaction are attained during the electronic excitation times. The average structural rearrangement for UVA-4-thiouridine (s4U)-induced crosslinking is larger than that for UVB or UVC-induced crosslinking; this is associated with the longer excitation time for s4U and is also consistent with transient conformational changes. The geometrical parameters do not completely predict the crosslinking frequencies, implicating other aspects of the tertiary structure or conformational flexibility in determining the frequencies and the locations of the crosslinking sites. The majority of the UVB/C and UVA-s4U-induced crosslinks are located in four regions in the 30 S subunit, within or at the ends of RNA helix 34, in the tRNA P-site, in the distal end of helix 28 and in the helix 19/helix 27 region. These regions are implicated in different aspects of tRNA accommodation, translocation and in the termination reaction. These results show that photocrosslinking is an indicator for sites where there is internucleotide conformational flexibility and these sites are largely restricted to parts of the 30 S subunit associated with ribosome function.
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MESH Headings
- Base Pairing
- Base Sequence
- Binding Sites
- Cross-Linking Reagents
- Escherichia coli/chemistry
- Escherichia coli/genetics
- Escherichia coli/radiation effects
- Models, Molecular
- Molecular Sequence Data
- Nucleic Acid Conformation/radiation effects
- Nucleotides/chemistry
- Nucleotides/metabolism
- Nucleotides/radiation effects
- Photochemistry
- Protein Conformation/radiation effects
- Protein Subunits
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/radiation effects
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/metabolism
- RNA, Ribosomal, 16S/radiation effects
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Ribosomal Proteins/chemistry
- Ribosomal Proteins/genetics
- Ribosomal Proteins/metabolism
- Ribosomes/chemistry
- Ribosomes/metabolism
- Ribosomes/radiation effects
- Ultraviolet Rays
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346
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Ghosh SK, Bharadwaj PK. Metal−Organic Framework H-Bonded Like a Polycatenane: Coexistence of Acyclic Water Trimer and Nonamer. Inorg Chem 2005; 44:5553-5. [PMID: 16060602 DOI: 10.1021/ic050727u] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pyridine-2,6-dicarboxylic acid and 1,2-di-4-pyridylethylene react hydrothermally with nickel(II) nitrate, forming a metal-organic framework that forms a polycatenane-like structure through H-bonding interactions between water molecules and carboxylate O atoms with void spaces. Discrete acyclic trimeric and nonameric water clusters occupy the voids in the structures. X-ray powder diffraction and X-ray structure analysis have been used to characterize this compound. Crystal data for 1 {(3dpeH(2))[Ni(pdc)(2)](3).15H(2)O}: monoclinic space group P2(1)/c, a = 24.730(5) Angstroms, b = 19.895(2) Angstroms, c = 17.257(4) Angstroms, beta = 104.832(5) degrees, V = 8208(4) Angstroms(3), Z = 4, R1 = 0.0429, wR2 = 0.1072, and S = 1.051.
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Ghosh SK, Ribas J, El Fallah MS, Bharadwaj PK. Mn(II) Staircase Structures Stitched by Water Clusters to a 3D Metal-Organic Open Framework: X-ray Structural and Magnetic Studies. Inorg Chem 2005; 44:3856-62. [PMID: 15907111 DOI: 10.1021/ic050102w] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
4-Hydroxypyridine-2,6-dicarboxylic acid (chelidamic acid, cdaH2) reacts with Mn(OAc)2 x 4H2O to form a 1D staircase structure with dimeric Mn(II) units connected by water clusters to form a 3D framework, {[Mn2(cda)2 x 4H2O] x 4H2O}n, 1, in aqueous pyridine at room temperature. The compound crystallizes in the triclinic space group P1 with a = 9.495(3), b =10.733(5), c = 11.065(4) A, alpha = 87.42(5), beta = 74.14(5), gamma = 80.07(2) degrees, U = 1068.5(9) A3, Z = 2, rho(calcd) = 1.915 g cm(-3), T = 100 K, mu = 1.28 mm(-1), R1 = 0.0453 (I > 2sigma(I)), wR2 = 0.1046, GOOF = 1.282. Upon removal of the water molecules by heating, the 3D structure breaks down. Thermogravimetric analysis, infrared, X-ray powder diffraction studies, and X-ray crystallography were performed to characterize this compound. Since the coordination polymer has diaqua-bridged Mn(II) centers, it was subjected to variable-temperature magnetic studies.
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Ghosh SK, Bharadwaj PK. Coordination Polymers of La(III) as Bunched Infinite Nanotubes and Their Conversion into an Open-Framework Structure. Inorg Chem 2005; 44:3156-61. [PMID: 15847422 DOI: 10.1021/ic048159q] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pyridine-2,6-dicarboxylic acid (pdcH2) reacts with LaCl3 x 7H2O under hydrothermal conditions followed by evaporation at room temperature to give a metal-organic framework structure of the empirical formula, [La(pdc)(H2O)4] x Cl (1), in the form of infinitely long bunched nanotubes. The chloride ions and water molecules occupy the tubular as well as the inter-tubular spaces. When La(NO3)3 x 7H2O is used in place of LaCl3 x 6H2O, a similar structure is formed with the empirical formula, [La(pdc)(H2O)4] x NO3 (2), where water molecules and the nitrate anions occupy the voids as in the case of 1. When an aqueous solution of AgNO3 is added to an aqueous solution of 1, the Cl- ions are replaced completely by NO3- ions to form 2; thus, the tubular structure is conserved. However, when AgBF4 is used in place of AgNO3, the tubular structure breaks down, and a new 3-D MOF structure, [La(pdc)(pdcH)(H2O)2] x 4H2O (3), is formed where the cavities are occupied by hexameric and dimeric water clusters. Structure 3 is also formed as the sole product when La(OAc)3 x xH2O is treated with pyridine-2,6-dicarboxylic acid following the method adopted for 1 and 2. Formation of the tubular structure depends on the molar ratio of the ligand and the metal. When higher than 1 equiv of the metal is taken, a linear coordination polymer, [La2(pdc)3(H2O)6] x 2H2O (4), is formed. This study provides the first nanotubular structure of a pure lanthanide metal.
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Webb CJ, Osman E, Ghosh SK, Hone S. Tonsillar size is an important indicator of recurrent acute tonsillitis. ACTA ACUST UNITED AC 2005; 29:369-71. [PMID: 15270824 DOI: 10.1111/j.1365-2273.2004.00819.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This prospective study was designed to identify important clinical features in patients with recurrent acute tonsillitis. A total of 195 consecutive children aged from 1 to 16 years were examined and a history of recurrent acute tonsillitis recorded. Patients with obstructive sleep apnoea or recent acute tonsillitis were excluded. Tonsil size was measured on the Brodsky scale [Brodsky L. (1989) Paediatr Clin N Am 36, 1551], tonsil symmetry, cervical lymphadenopathy, and hyperaemia of the anterior pillars was recorded. Patients with a history of recurrent tonsillitis had larger tonsils than those without tonsillitis (P < 0.001). Tonsil asymmetry and cervical lymphadenopathy were more common in patients with recurrent tonsillitis (P < 0.001). Anterior pillar hyperaemia was also more frequent in recurrent tonsillitis (P < 0.01). In addition to the frequency and severity of tonsillitis it is suggested that the size and symmetry of the tonsils, plus cervical lymphadenopathy and anterior pillar hyperaemia should be taken into account when deciding which patients would benefit from tonsillectomy.
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Ghosh SK, Norris JL. Bayesian capture-recapture analysis and model selection allowing for heterogeneity and behavioral effects. JOURNAL OF AGRICULTURAL BIOLOGICAL AND ENVIRONMENTAL STATISTICS 2005. [DOI: 10.1198/108571105x28651] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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