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Verma R, Mishra M, Dhar R, Dabrowski R. Single walled carbon nanotubes persuaded optimization of the display parameters of a room temperature liquid crystal 4-pentyl-4′cyanobiphenyl. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.05.045] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Alfouzan W, Dhar R, Ashkanani H, Gupta M, Rachel C, Khan ZU. Species spectrum and antifungal susceptibility profile of vaginal isolates of Candida in Kuwait. J Mycol Med 2014; 25:23-8. [PMID: 25534676 DOI: 10.1016/j.mycmed.2014.10.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 10/27/2014] [Accepted: 10/30/2014] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The study was undertaken to determine the prevalence of vulvovaginal candidiasis (VVC) among patients with vaginitis, frequency of different Candida species, and their susceptibility profile. PATIENTS AND METHODS Over six months period, high vaginal swabs were cultured on Sabouraud's dextrose agar and isolates were identified by culture on CHROMagar Candida and Vitek2 yeast identification system or/and API 20C (BioMerieux, France). Antifungal susceptibility of the Candida isolates was determined by E-test against amphotericin B, flucytosine, fluconazole, voriconazole, posaconazole and caspofungin. RESULTS One thousand seven hundred and fifty-two women with vaginitis were screened for the prevalence of Candida spp. Vaginal swab cultures of 231 (13.2%) women yielded Candida spp. The isolation rates of different species were as follows: Candida albicans (73.9%), Candida glabrata (19.8%), Candida kefir (1.94%), Candida tropicalis (0.96%), Candida parapsilosis (0.96%), Candida krusei (0.96%), Candida guilliermondii (0.96%), and Saccharomyces cerevisiae (0.52%). All strains of C. albicans and non-C. albicans were susceptible to most of the antifungal agents tested. CONCLUSION The high frequency with which C. albicans was recovered and its azole susceptibility support the continued use of azole agents for empirical therapy of uncomplicated VVC. However, a larger controlled study is required to determine the role of non-C. albicans in recurrent VVC.
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Li G, Ci W, Karmakar S, Chen K, Dhar R, Fan Z, Guo Z, Zhang J, Ke Y, Wang L, Zhuang M, Hu S, Li X, Zhou L, Li X, Calabrese MF, Watson ER, Prasad SM, Rinker-Schaeffer C, Eggener SE, Stricker T, Tian Y, Schulman BA, Liu J, White KP. SPOP promotes tumorigenesis by acting as a key regulatory hub in kidney cancer. Cancer Cell 2014; 25:455-68. [PMID: 24656772 PMCID: PMC4443692 DOI: 10.1016/j.ccr.2014.02.007] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 10/26/2013] [Accepted: 02/14/2014] [Indexed: 01/29/2023]
Abstract
Hypoxic stress and hypoxia-inducible factors (HIFs) play important roles in a wide range of tumors. We demonstrate that SPOP, which encodes an E3 ubiquitin ligase component, is a direct transcriptional target of HIFs in clear cell renal cell carcinoma (ccRCC). Furthermore, hypoxia results in cytoplasmic accumulation of SPOP, which is sufficient to induce tumorigenesis. This tumorigenic activity occurs through the ubiquitination and degradation of multiple regulators of cellular proliferation and apoptosis, including the tumor suppressor PTEN, ERK phosphatases, the proapoptotic molecule Daxx, and the Hedgehog pathway transcription factor Gli2. Knockdown of SPOP specifically kills ccRCC cells, indicating that it may be a promising therapeutic target. Collectively, our results indicate that SPOP serves as a regulatory hub to promote ccRCC tumorigenesis.
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Salvi SS, Kodgule RR, Dhar R, Gogtay JA, Koul PA, Singh V, Saicharan BG, Madas SJ. Reference values for peak expiratory flow in Indian adult population using a European Union scale peak flow meter. J Postgrad Med 2014; 60:123-9. [DOI: 10.4103/0022-3859.132311] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Pandey MB, Verma R, Dhar R. Dielectric and Electro-Optical Properties of Antiferroelectric Liquid Crystalline Materials. Isr J Chem 2012. [DOI: 10.1002/ijch.201200041] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Dhar R, Sägesser R, Weikert C, Yuan J, Wagner A. Adaptation of Saccharomyces cerevisiae to saline stress through laboratory evolution. J Evol Biol 2011; 24:1135-53. [PMID: 21375649 DOI: 10.1111/j.1420-9101.2011.02249.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Most laboratory evolution studies that characterize evolutionary adaptation genomically focus on genetically simple traits that can be altered by one or few mutations. Such traits are important, but they are few compared with complex, polygenic traits influenced by many genes. We know much less about complex traits, and about the changes that occur in the genome and in gene expression during their evolutionary adaptation. Salt stress tolerance is such a trait. It is especially attractive for evolutionary studies, because the physiological response to salt stress is well-characterized on the molecular and transcriptome level. This provides a unique opportunity to compare evolutionary adaptation and physiological adaptation to salt stress. The yeast Saccharomyces cerevisiae is a good model system to study salt stress tolerance, because it contains several highly conserved pathways that mediate the salt stress response. We evolved three replicate lines of yeast under continuous salt (NaCl) stress for 300 generations. All three lines evolved faster growth rate in high salt conditions than their ancestor. In these lines, we studied gene expression changes through microarray analysis and genetic changes through next generation population sequencing. We found two principal kinds of gene expression changes, changes in basal expression (82 genes) and changes in regulation (62 genes). The genes that change their expression involve several well-known physiological stress-response genes, including CTT1, MSN4 and HLR1. Next generation sequencing revealed only one high-frequency single-nucleotide change, in the gene MOT2, that caused increased fitness when introduced into the ancestral strain. Analysis of DNA content per cell revealed ploidy increases in all the three lines. Our observations suggest that evolutionary adaptation of yeast to salt stress is associated with genome size increase and modest expression changes in several genes.
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Tajuddin T, Razif S, Dhar R, Thorne J, Murray FE. Clinical presentation of adult coeliac disease. IRISH MEDICAL JOURNAL 2011; 104:20-22. [PMID: 21387881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The mode of presentation of coeliac disease has been changing to more atypical or silent disease. Few studies described the clinical presentation of adult coeliac disease in Ireland in recent years. We retrospectively collected the clinical data for all patients who had a diagnosis of coeliac disease made in our centre between January 07 and December 08. Forty seven adults, predominantly females (n = 30), had a confirmed diagnosis of coeliac disease made during the study period. In our patient cohort, the presenting symptom was diarrhoea in 19 (40%) patients, while 16 patients (34%) did not have any G.I. symptoms, 10 (21%) presented with anaemia. Females presented at a significantly younger age compared to males, with median ages at diagnosis of 44.5 and 57 years, respectively (p = 0.04). Females also presented more commonly with non G.I. symptoms (p = 0.07). The reasons behind this gender difference need further study.
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Dhar R, Anwar GA, Bourke SC, Doherty L, Middleton P, Ward C, Rutherford RM. Efficacy of nebulised colomycin in patients with non-cystic fibrosis bronchiectasis colonised with Pseudomonas aeruginosa. Thorax 2010; 65:553. [PMID: 20522858 DOI: 10.1136/thx.2008.112284] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Dhar R, Kumar S, Gupta M, Agrawal V. Thermodynamic, optical and dielectric studies of the homologous members of columnar discotic compound Rufigallol hexa-n-alkoxylates. J Mol Liq 2008. [DOI: 10.1016/j.molliq.2008.02.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pandey MB, Dhar R, Dabrowski R. Characteristics of the collective dielectric relaxation mode of the incommensurate SmC(α)(*) phase. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2008; 20:115207. [PMID: 21694224 DOI: 10.1088/0953-8984/20/11/115207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Employing the dielectric relaxation spectroscopy technique, we have observed two different characteristics of the collective relaxation mode of an incommensurate SmC(α)(*) phase. Recent theoretical advances predict two different natures for the dielectric relaxation mode in the SmC(α)(*) phase. Our experimental results confirm two different behaviours of the relaxation mode in different temperature ranges for this phase for one unique compound having an exceptionally wide temperature range (∼9 °C) for the SmC(α)(*) phase.
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Udo EE, Al-Sweih N, Dhar R, Dimitrov TS, Mokaddas EM, Johny M, Al-Obaid IA, Gomaa HH, Mobasher LA, Rotimi VO, Al-Asar A. Surveillance of antibacterial resistance in Staphylococcus aureus isolated in Kuwaiti hospitals. Med Princ Pract 2008; 17:71-5. [PMID: 18059105 DOI: 10.1159/000109594] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To investigate the prevalence of antibiotic resistance among Staphylococcus aureus isolated in Kuwaiti hospitals. MATERIALS AND METHODS S. aureus were isolated and identified following standard microbiological methods. Antibacterial susceptibility test was performed by disk diffusion and the measurement of minimum inhibitory concentration with E-test strips. RESULTS A total of 1,846 S. aureus isolates were analyzed from 13 hospitals between 1 March and 30 October 2005. They were isolated from 1,765 (95.6%) inpatients and 81 (4.4%) outpatients. Methicillin resistance was detected in 588 (32.0%) of the isolates. The methicillin-resistant S. aureus (MRSA) consisted of 461 (78%) multiresistant and 127 (22%) nonmultiresistant isolates. The nonmultiresistant MRSA consisted of epidemic MRSA-15 and community-associated MRSA. The community-associated MRSA was detected in all hospitals with MRSA, indicating its establishment in Kuwaiti hospitals. The proportion of isolates resistant to gentamicin, kanamycin, erythromycin, tetracycline, ciprofloxacin, fusidic acid and trimethoprim was higher among MRSA than methicillin-susceptible S. aureus (MSSA) isolates. Twenty-four and 22% of MRSA and MSSA isolates, respectively, expressed reduced susceptibility to vancomycin (minimum inhibitory concentration = 3-4 mg/l). CONCLUSION The study revealed the presence of methicillin resistance in 32% of S. aureus isolated in Kuwaiti hospitals and revealed an increase in the number of MRSA and MSSA with reduced susceptibility to vancomycin.
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John Albert M, Al-Mekhaizeem K, Neil L, Dhar R, Dhar PM, Al-Ali M, Al-Abkal HM, Haridas S. High prevalence and level of resistance to metronidazole, but lack of resistance to other antimicrobials in Helicobacter pylori, isolated from a multiracial population in Kuwait. Aliment Pharmacol Ther 2006; 24:1359-66. [PMID: 17059517 DOI: 10.1111/j.1365-2036.2006.03144.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND The primary treatment regimen for Helicobacter pylori infection for Kuwaitis does not contain metronidazole, but that for expatriates does. There is also increasing failure of antimicrobial therapy. AIM To determine the susceptibility of H. pylori from upper gastrointestinal biopsies of Kuwaitis and non-Kuwaitis to find out if differences existed in the susceptibilities of the isolates from the two different populations. METHODS The susceptibilities of 96 H. pylori isolates were tested against metronidazole, amoxicillin, clarithromycin and tetracycline by the E test. The rdxA gene was analysed from selected metronidazole-susceptible and metronidazole-resistant strains to find out polymorphism and the basis of metronidazole resistance. RESULTS Approximately, 70% of isolates from both populations were metronidazole resistant with 65% isolates showing high minimum inhibitory concentration values of >256 mug/mL. No resistance to the other three antimicrobials was found. There were novel nonsense and missense mutations with no deletion in the rdxA gene by insertion of mini-IS605. CONCLUSIONS The prevalence and level of metronidazole resistance in H. pylori in the two populations was high with no difference, in spite of different treatment regimens. Metronidazole resistance in this transitional country appeared to be independent of prior metronidazole use for treatment of H. pylori infection.
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Bignardi GE, Dhar R, Heycock R, Bansal S, Majmudar N. Can procalcitonin testing reduce antibiotic prescribing for respiratory infections? Age Ageing 2006; 35:625-6. [PMID: 16822805 DOI: 10.1093/ageing/afl054] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Dhar R, Copson D, Williamson K, Nunns D. Use of topical negative pressure to close a large MRSA-infected groin wound following vulvectomy. J Wound Care 2006; 15:312-3. [PMID: 16869199 DOI: 10.12968/jowc.2006.15.7.26935] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Fraenkel L, Rabidou N, Dhar R. Are rheumatologists' treatment decisions influenced by patients' age? Rheumatology (Oxford) 2006; 45:1555-7. [PMID: 16690762 PMCID: PMC1660557 DOI: 10.1093/rheumatology/kel144] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The objective of this study was to determine whether physicians' treatment preferences are influenced by patients' age. METHODS We mailed a survey to a random sample of rheumatologists practicing in the US. The survey included a scenario describing a hypothetical patient with rheumatoid arthritis (RA) on hydroxychloroquine, sulfasalazine and low-dose prednisolone, who presents with active disease during a follow-up appointment. The scenario was formulated in two versions that were identical except for the age of the patient. After reading the scenario, respondents were asked to rate (on a 10 cm numerical rating scale) their recommendations for each of the three options: (i) increasing the dose of prednisolone, (ii) adding a new disease-modifying anti-rheumatic drug (DMARD) and (iii) switching DMARDs. Rheumatologists who rated either adding a new DMARD or switching DMARDs higher than increasing the dose of prednisolone were classified as 'preferring aggressive treatment with DMARDs', while the others were classified as 'NOT preferring aggressive treatment with DMARDs'. RESULTS A total of 480 rheumatologists were mailed a questionnaire; 204 responded, giving a response rate of 42.5%. Overall 163 (80%) respondents were classified as preferring aggressive treatment with DMARDs. Rheumatologists responding to this survey were more likely to prefer aggressive DMARD treatment for the young RA patient vs the older RA patient (87 vs 71%, P= 0.007). CONCLUSIONS Our findings suggest that rheumatologists' treatment recommendations may be influenced by age. Future educational efforts should increase physician awareness of this possible bias in order to ensure equal service delivery across ages.
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Gupta M, Dhar R, Agrawal VK, Dabrowski R, Tykarska M. Dielectric spectroscopy of a binary mixture of liquid crystals showing wide temperature range twisted grain boundary phase with re-entrant cholesteric phase. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:021703. [PMID: 16196581 DOI: 10.1103/physreve.72.021703] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Indexed: 05/04/2023]
Abstract
There are only few materials, which have shown long temperature range twisted grain boundary (TGB) phases. One such material is the chiral binary mixture of 7OCB and 5* CBB (mole ratio 0.8 and 0.2) which shows unique phase sequence of cholesteric ( N*) , a wide temperature range TGBA (approximately 31 degrees C) and reentrant cholesteric (N*re) phases. In the present work we are reporting the dielectric spectroscopy of the above mixture with a chiral analog of earlier reported nematic (N) , smectic- A (SmA) , and reentrant nematic (Nre) phase sequences [Phys. Rev. A 46, 7733 (1992)] for different conditions of molecular orientations. Two modes of dielectric relaxations have been detected in a homeotropically aligned sample with unusually low relaxation frequencies for one of them. Planar oriented molecules in the TGBA phase show a soft mode of relaxation and support the recently proposed theory for the soft mode relaxation of the TGBA phase [Phys. Rev. E 65, 11701 (2001)]. By applying the dc electric field on planar oriented molecules in the TGBA phase, it has been possible to obtain a helix free homeotropically aligned TGBA phase.
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Behbehani N, Mahmood A, Mokaddas EM, Bittar Z, Jayakrishnan B, Khadadah M, Pacsa AS, Dhar R, Chugh TD. Significance of atypical pathogens among community-acquired pneumonia adult patients admitted to hospital in Kuwait. Med Princ Pract 2005; 14:235-40. [PMID: 15961932 DOI: 10.1159/000085741] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2004] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES The aim of this study is to determine the microbial etiology and severity of community-acquired pneumonia (CAP) in Kuwait. SUBJECTS AND METHODS The severity of consecutive adult CAP cases admitted to 3 hospitals over a 1-year period was classified according to the Pneumonia Outcome Research Team (PORT) severity index. The microbial etiology was determined using standard methods for bacteria and serological tests for atypical and viral pathogens. RESULTS The study population was 124 of the 135 admissions; 63 female, 61 male; mean age 41.3+/-18 years. The severity class distribution was: class I 31%, class II 37%, class III 17%, class IV 13%, and class V 2%. Etiological agents were identified from 44 patients (35%), with one pathogen in 31 (25%), two in 9 (7%), and three or more in 4 (3%). The most common pathogens identified were: Mycoplasma pneumoniae in 14 patients (11%), Legionella pneumophila in 10 (8%), Chlamydia pneumoniae in 8 (6%), influenza B virus in 8 (6%), influenza A virus in 5 (4%), Haemophilus influenzae in 4 (3%), Streptococcus pneumoniae in 3 (2%), Staphylococcus aureus in 3 (2%), gram-negative enterobacteria in 5 (4%), Moraxellacatarrhalis in 2 (2%), and viruses in 4 (3%). The yields from laboratory tests were 48% for paired serology, 20% from adequate sputum sample, and 3% from blood culture. CONCLUSION Our study shows that a large percentage of mild CAP cases are admitted to hospitals in Kuwait. Atypical pathogens have a significant role in the etiology of CAP. There is overtreatment of CAP with a combination treatment consisting mainly of third-generation chephalosporins and macrolides.
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Karmakar S, Dhar R, Das C. Inhibition of Cytotrophoblastic (JEG-3) Cell Invasion by Interleukin 12 Involves an Interferon γ-mediated Pathway. J Biol Chem 2004; 279:55297-307. [PMID: 15448160 DOI: 10.1074/jbc.m407013200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trophoblast invasion, like tumor invasion, shares common biochemical mechanisms. However, in contrast to tumor invasion of a host tissue, trophoblastic invasion during implantation is strictly regulated, temporospatially. Factors responsible for these important regulatory processes are presently unknown; however, studies indicate that cytokines and growth factors represent in the peri-implantation uterine milieu as the possible candidates. In this study we investigated the role of interleukin (IL) 12 in regulating trophoblast invasion and the expression of trophoblast proteases (matrix metalloprotease (MMP)-2, MMP-9, and urokinase-type plasminogen activators) and their inhibitors (tissue inhibitors of metalloprotease (TIMP) 1, TIMP-2, and plasminogen activator inhibitor (PAI)-1) using an in vitro tissue culture system of human choriocarcinoma cell line JEG-3. Our major findings show an anti-invasive role of IL-12, associated with an inhibitory effect on the proteases but with an opposite up-regulating influence on the protease inhibitor, TIMP-1, whereas TIMP-2 and plasminogen activator inhibitor 1 remained unaltered. Stimulation of JEG-3 cells with IL-12 also induced interferon (IFN)-gamma production, which when neutralized using a monoclonal anti-IFN-gamma antibody, F12, abrogates its ability to down-regulate the MMPs. IL-12 also mediates an IFN-gamma-dependent up-regulation of E-cadherin, thereby implying that alteration in cell-cell adhesion besides regulating the proteases and the inhibitors possibly contributes to the observed anti-invasive role of this cytokine. TIMP-1, although stimulated by IL-12, was found to be unaltered by antibody F12, thereby implying a possibility of an IL-12-dependent-IFN-gamma independent regulation. These findings thereby suggest an important role of IL-12 in modulation of trophoblast proteases and their inhibitors besides regulating cell-cell interactions and invasion during implantation, with far reaching possibilities for understanding the mechanism(s) and regulations of invasion and metastasis.
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Dhar R, Karmakar S, Sriraman R, Talwar GP, Das C. Efficacy of a Recombinant Chimeric Anti-hCG Antibody to Prevent Human Cytotrophoblasts Fusion and Block Progesterone Synthesis. Am J Reprod Immunol 2004; 51:358-63. [PMID: 15212672 DOI: 10.1111/j.1600-0897.2004.00169.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PROBLEM A recombinant chimeric antibody against hCG (cPIPP) has been engineered and expressed at high yield in plants. The purpose of this work was to enquire whether this antibody is competent to neutralize the bioactivity of hCG on human trophoblasts. METHODS Cytotrophoblast cells, isolated from term placentae were maintained in culture for 3 days in presence or absence of humanized chimeric anti-hCG antibodies. Progesterone secreted was quantitated by ELISA. Fusion and cyto-architecture of the cells was studied by light and electron microscopy. Modulation of E-cadherin was investigated using RT-PCR and immunocytochemistry. RESULTS Recombinant chimeric anti-hCG antibody blocked the synthesis of progesterone by trophoblasts. No fusion of cytotrophoblasts to form syncytium took place. E-cadherin, a vital cell adhesion molecule involved in cell-to-cell interaction did not show differentiation related decline in its expression in presence of the antibody. CONCLUSION Recombinant chimeric anti-hCG antibody (cPIPP) was effective to neutralize hCG induced bioactivities in the human derived trophoblast cells.
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Basak S, Dhar R, Das C. Steroids modulate the expression of alpha4 integrin in mouse blastocysts and uterus during implantation. Biol Reprod 2002; 66:1784-9. [PMID: 12021063 DOI: 10.1095/biolreprod66.6.1784] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Blastocyst implantation and successful establishment of pregnancy require delicate interactions between the embryo and the maternal uterine milieu, which are controlled at the embryo-maternal interface by the coordinated interplay of a variety of growth factors, cytokines, hormones, and cell adhesion molecules expressed by both the decidualized endometrium and the trophoblast cells. Proper implantation of the embryo is solely dependent on the initial endometrial receptivity and the preparation of the blastocyst to glue itself to the uterine wall. Both these events are considered to be mediated by cell adhesion molecules and integrins expressed by the blastocyst as well by as the maternal endometrium. Integrin expression by the blastocyst and the uterus is a dynamic process. However, reports on the expression and the hormonal modulation of integrins and their role in blastocyst activation and uterine receptivity during implantation are meager. The present study investigates the expression and hormonal regulation of alpha4beta1 integrin by steroid hormones in the blastocyst and the receptive uterus using an in vivo, delayed-implantation mouse model system. The dormant and activated blastocysts as well as the uteri were recovered from ovariectomized mice after progesterone-alone and progesterone-plus-estrogen therapy, respectively. Immunolocalization of protein expression of alpha4 and beta1 integrin subunits indicate that steroids modulate the expression of alpha4beta1 integrin receptor in the mouse blastocyst as well as the uterus and that a differential expression is observed with exposure to progesterone and estrogen. Intrauterine blocking of alpha4 integrin by specific antibody resulted in implantation failure in normal as well as in delayed-implantation mice. Based on our data, we propose here, to our knowledge for the first time, that alpha4beta1 integrin, which is responsible for binding to fibronectin and vascular cell adhesion molecule-1, is induced by estradiol and is down-regulated by progesterone in mice during implantation. Furthermore, the results also indicate the direct role of alpha4 integrin in the process of implantation.
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Abstract
Although the consumer research field has made great progress over the past 30 years with respect to the scope, quality, and quantity of research, there are still significant disagreements about what consumer research is, what its objectives are, and how it should differ from related disciplines. As a result, the field appears to be rather fragmented and even divided on some fundamental issues. In this review we first examine the original vision for the field and its limitations. In the second section we explore the consequences of the ambiguity about the domain and identity of consumer research and the multidisciplinary influences on the field. In particular, we review key trends and "camps" in consumer research, which represent complementary and, in some cases, conflicting views regarding the main topics of investigation and how research is conducted. This review is based in part on systematic analyses of articles that have been published in the leading consumer research journals over the past 30 years. Finally, in the third section we revisit the question of what might differentiate the field from related disciplines, as well as the role of theory testing, studies of substantive phenomena, and relevance in consumer research.
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Ortega RA, Dhar R, Rengasamy SK. Hematoma compression over the right internal jugular vein resulting in a pulseless ipsilateral arm. J Cardiothorac Vasc Anesth 2001; 15:141. [PMID: 11254859 DOI: 10.1053/jcan.2001.20393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Bica I, McGovern B, Dhar R, Stone D, McGowan K, Scheib R, Snydman DR. Increasing mortality due to end-stage liver disease in patients with human immunodeficiency virus infection. Clin Infect Dis 2001; 32:492-7. [PMID: 11170959 DOI: 10.1086/318501] [Citation(s) in RCA: 702] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2000] [Revised: 11/08/2000] [Indexed: 12/15/2022] Open
Abstract
Highly active antiretroviral therapy has decreased human immunodeficiency virus (HIV)-associated mortality; other comorbidities, such as chronic liver disease, are assuming greater importance. We retrospectively examined the causes of death of HIV-seropositive patients at our institution in 1991, 1996, and 1998-1999. In 1998-1999, 11 (50%) of 22 deaths were due to end-stage liver disease, compared with 3 (11.5%) of 26 in 1991 and 5 (13.9%) of 36 in 1996 (P=.003). In 1998-1999, 55% of patients had nondetectable plasma HIV RNA levels and/or CD4 cell counts of >200 cells/mm(3) within the year before death. Most of the patients that were tested had detectable antibodies to hepatitis C virus (75% of patients who died in 1991, 57.7% who died in 1996, and 93.8% who died in 1998-1999; P=NS). In 1998-1999, 7 patients (31.8%) discontinued antiretroviral therapy because of hepatotoxicity, compared with 0 in 1991 and 2 (5.6%) in 1996. End-stage liver disease is now the leading cause of death in our hospitalized HIV-seropositive population.
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Brennan JD, Kent M, Dhar R, Fujioka H, Kumar N. Anopheles gambiae salivary gland proteins as putative targets for blocking transmission of malaria parasites. Proc Natl Acad Sci U S A 2000; 97:13859-64. [PMID: 11087838 PMCID: PMC17666 DOI: 10.1073/pnas.250472597] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Anopheles gambiae is the primary vector of human malaria in sub-Saharan Africa. Invasion of Anopheles salivary glands by Plasmodium sporozoites is a necessary step in the transmission of malaria and is likely to be mediated by specific receptor-ligand interactions. We are interested in identifying putative an A. gambiae salivary gland receptor or receptors for sporozoite invasion as a possible target for blocking malaria transmission. By using monoclonal antibodies against female-specific A. gambiae salivary gland proteins, two molecules, one of 29 kDa and one of 100 kDa, were identified and characterized with respect to the age and blood-feeding process of mosquitoes. In an in vivo bioassay, the monoclonal antibody against the 100-kDa protein inhibited Plasmodium yoelii sporozoite invasion of salivary glands >/=75%. These results show that A. gambiae salivary gland proteins are accessible to monoclonal antibodies that inhibit sporozoite invasion of the salivary glands and suggest alternate targets for blocking the transmission of malaria by this most competent of malaria vectors.
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Yoon JH, Love DC, Guhathakurta A, Hanover JA, Dhar R. Mex67p of Schizosaccharomyces pombe interacts with Rae1p in mediating mRNA export. Mol Cell Biol 2000; 20:8767-82. [PMID: 11073978 PMCID: PMC86506 DOI: 10.1128/mcb.20.23.8767-8782.2000] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We identified the Schizosaccharomyces pombe mex67 gene (spmex67) as a multicopy suppressor of rae1-167 nup184-1 synthetic lethality and the rae1-167 ts mutation. spMex67p, a 596-amino-acid-long protein, has considerable sequence similarity to the Saccharomyces cerevisiae Mex67p (scMex67p) and human Tap. In contrast to scMEX67, spmex67 is essential for neither growth nor nuclear export of mRNA. However, an spmex67 null mutation (Deltamex67) is synthetically lethal with the rae1-167 mutation and accumulates poly(A)(+) RNA in the nucleus. We identified a central region (149 to 505 amino acids) within spMex67p that associates with a complex containing Rae1p that complements growth and mRNA export defects of the rae1-167 Deltamex67 synthetic lethality. This region is devoid of RNA-binding, N-terminal nuclear localization, and the C-terminal nuclear pore complex-targeting regions. The (149-505)-green fluorescent protein (GFP) fusion is found diffused throughout the cell. Overexpression of spMex67p inhibits growth and mRNA export and results in the redistribution of the diffused localization of the (149-505)-GFP fusion to the nucleus and the nuclear periphery. These results suggest that spMex67p competes for essential mRNA export factor(s). Finally, we propose that the 149-505 region of spMex67p could act as an accessory factor in Rae1p-dependent transport and that spMex67p participates at various common steps with Rae1p export complexes in promoting the export of mRNA.
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