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Agrawal L, Kaur P, Singh J, Singh N. Pilomatrixoma misdiagnosed as round cell tumor on fine-needle aspiration cytology. Indian J Cancer 2011; 47:483-5. [PMID: 21131775 DOI: 10.4103/0019-509x.73565] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Varma MC, Kushner YB, Ko DS, Kawai T, Martins PN, Martins P, Kaur P, Markmann JF, Kotton CN. Early onset adenovirus infection after simultaneous kidney-pancreas transplant. Am J Transplant 2011; 11:623-7. [PMID: 21342452 DOI: 10.1111/j.1600-6143.2010.03408.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Adenoviruses (AdV) are increasingly recognized as important viral pathogens in immunocompromised hosts. The clinical spectrum ranges from asymptomatic viremia to allograft dysfunction, and death. Most of the medical literature is on AdV infection in children and bone marrow transplant recipients. We report a case of AdV in an adult recipient in the first month after simultaneous kidney-pancreas transplant with thymoglobulin induction. This is a rare report of adenovirus infection after multiorgan transplant, and is unique in that it exhibited tissue invasive disease without any localizing signs or allograft dysfunction, while other cases in medical literature had invasive disease of the allograft with allograft dysfunction, failure, or death. In addition, this is the first report of a radiologic presentation of AdV nephritis.
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Kaur P, Filia G, Singh S, Patil P, Ravi Kumar G, Sandhu K. Molecular epidemiology of Mycobacterium avium subspecies paratuberculosis: IS900 PCR identification and IS1311 polymorphism analysis from ruminants in the Punjab region of India. Comp Immunol Microbiol Infect Dis 2011; 34:163-9. [DOI: 10.1016/j.cimid.2010.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 09/28/2010] [Indexed: 11/28/2022]
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Kaur P, Bansal R, Madan M. Trichoadenoma in a mature cystic teratoma: a rare finding. Gulf J Oncolog 2011:65-67. [PMID: 21177212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2010] [Indexed: 05/30/2023]
Abstract
Skin adnexal tumors arising in dermoid cysts of the ovary are exceedingly rare. We report a trichoadenoma arising in a dermoid cyst in a 42-year-old female. The histopathology of trichoadenoma has also been described briefly. Mature teratomas, which are almost all cystic (dermoid cysts), account for approximately 25% of all ovarian tumors, and 30% of benign ovarian tumors. They usually develop in children or women of the reproductive age group. Histologically, they are composed of variable proportions of tissue originating from the ectoderm, mesoderm, and endoderm. Cystic cavities are lined by mature epidermis. Although skin appendages and neural tissue are extremely common, there are only few case reports of skin adnexal tumors arising in a mature teratoma. We report a case of ovarian teratoma with a trichoadenoma. To the best of the authors' knowledge, this is the first report describing this rare benign skin adnexal tumor, in a mature cystic teratoma of the ovary.
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Asea A, Pradeep A, Kaur P, Bempong P, Lillard S. Abstract P6-08-08: Nucleolin as an Intracellular Transporter of Hsp72. Cancer Res 2010. [DOI: 10.1158/0008-5472.sabcs10-p6-08-08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Our previous studies demonstrated that thermal stress induces the release of Hsp72 from cells by a mechanism independent of the classical protein transport pathway. However, the exact mechanism by which Hsp72, a leaderless protein, gains access to the extracellular milieu remains unknown.
Materials and Methods: In this study we use flow cytometry to measure the expression of surface bound Hsp72 in THP1 human monocytic cells. Sucrose gradient ultracentrifugation was also used to isolate and recover intracellular fractions. Western blot analysis was used to probe for intracellular fractions expressing Hsp72, Hsp90, Grp96, CAP2, TLR2, 4, or 7. Baculovirus expression vector system (BEVS) was used to generate highly purified endotoxin free Hsp72. Plasma membrane cross-linking assay was used to identify the interacting proteins of Hsp72 on cell plasma membrane. Laser scanning confocal microscopy was used to demonstrate the plasma membrane localization and internalization of Hsp72 with other interacting proteins. In-gel digestion and LC-mass spectrometry was used to identify unique proteins colocalizing with Hsp72. Results: The data presented in this study suggest that Hsp72 trafficking within the cell and its release is assisted in part by, nucleolin. We further demonstrate that within 60 minutes after first exposure of cells to heat shock treatment, plasma membrane bound Hsp72 is internalized and redistributed into cytosolic compartments. Inhibition of active cell transport by pre-treatment of cells with Cytochalasin B completely abrogated Hsp72 redistribution from the plasma membrane into the cytosol. Cross-linking of plasma membrane bound proteins with Hsp72 followed by Western blot analysis, in-gel digestion and LC-MS/MS analysis revealed seven interacting partners with Hsp72, including Hsp90, nucleolin, gp96, CAP2, TLR2, 4 and 7. Transfection of cells with nucleolin-siRNA completely inhibited baseline and heat shock-induced Hsp72 release. Discussion: Our study for the first time demonstrates that the plasma membrane acts as a reservoir for Hsp72 and confirms that nucleolin plays an important role in Hsp72 trafficking and release.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-08-08.
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Kaur P, Lehri A, Verma SK. Study of relationship between the ECG components and some anthropometric measurements. Br J Sports Med 2010. [DOI: 10.1136/bjsm.2010.078725.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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107
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Sun YJ, Kaur P, Leo Y. Molecular epidemiology of HIV-1 in newly-diagnosed treatment-naïve patients in Singapore. Int J Infect Dis 2010. [DOI: 10.1016/j.ijid.2010.02.1668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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108
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Sun YJ, Kaur P, Leo Y. Prevalence of minor populations of drug-resistant HIV-1 in newly-diagnosed treatment-naïve individuals in Singapore. Int J Infect Dis 2010. [DOI: 10.1016/j.ijid.2010.02.2034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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109
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Kaur P, Satyanarayana T. Improvement in cell-bound phytase activity of Pichia anomala by permeabilization and applicability of permeabilized cells in soymilk dephytinization. J Appl Microbiol 2009; 108:2041-9. [PMID: 19922597 DOI: 10.1111/j.1365-2672.2009.04607.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS Whole cell permeabilization of Pichia anomala to ameliorate the cell-bound phytase activity and usability of permeabilized cells in dephytinization of soymilk. METHODS AND RESULTS The cells of P. anomala were subjected to permeabilization using the surfactant Triton X-100 to overcome the permeability barrier and prepare whole cell biocatalysts with high phytase activity. The statistical approach, response surface methodology (RSM) was used to optimize the operating conditions for permeabilization. The treatment of cells with 5% Triton X-100 for 30 min resulted in c. 15% enhancement in cell-bound phytase activity. The shrinkage of protoplast was observed, although cell viability and phytase stability were not significantly altered. The free as well as immobilized permeabilized cells hydrolysed soymilk phytate, and the latter could be reused over four consecutive cycles. CONCLUSIONS Whole cell permeabilization of P. anomala using Triton X-100 led to enhancement in cell-bound phytase activity. The viability and integrity of yeast cells were not significantly affected because of permeabilization. The permeabilized P. anomala cells effectively dephytinized soymilk, and the permeabilized cells immobilized in alginate could be reused because of sustained phytase activity. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first report on the use of permeabilized yeast cells for mitigating phytate content of soymilk. Alginate entrapment of permeabilized P. anomala allows reuse of cells for soymilk dephytinization, thus suggesting a potential application in food industry.
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Gupta R, Deepanjali S, Thabah MM, Kaur P, Gupta S. Successful twin pregnancy while on cyclophosphamide therapy in a patient with lupus nephritis. Rheumatol Int 2009; 29:1503-5. [DOI: 10.1007/s00296-009-0860-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2008] [Accepted: 01/05/2009] [Indexed: 10/21/2022]
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Sahu S, Kaur P. Thanatophoric Dysplasia : Antenatal Diagnosis. Med J Armed Forces India 2009; 65:87-8. [DOI: 10.1016/s0377-1237(09)80071-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2008] [Accepted: 08/29/2008] [Indexed: 10/18/2022] Open
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Sobti RC, Gupta L, Singh SK, Seth A, Kaur P, Thakur H. Role of hormonal genes and risk of prostate cancer: gene-gene interactions in a North Indian population. ACTA ACUST UNITED AC 2008; 185:78-85. [PMID: 18722876 DOI: 10.1016/j.cancergencyto.2008.04.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 04/15/2008] [Accepted: 04/15/2008] [Indexed: 10/21/2022]
Abstract
Prostate cancer represents a heterogeneous disease with varying degrees of aggressiveness, patterns of metastasis, and response to therapy. It arises from a complex etiology that involves both exogenous (diet, environment, etc.) and endogenous (hormonal and genetic) factors. The present study was performed to explore the role of various genotypes involved in steroid metabolism and synthesis in the causation of prostate cancer. Genetic polymorphism of the ER, CYP17, SRD5A2 (TA repeats), and PSA genes were analyzed in 157 cases of prostate cancer and 340 controls [170 healthy males and 170 patients of benign prostate hyperplasia (BPH)]. Mutant genotypes of ER and CYP17 showed 2- and 3- and 3.5-fold increased risk of prostate cancer, respectively, as compared to BPH and healthy controls. Interaction of mutant (homozygous and heterozygous) alleles of CYP17 with TA (0/0) led to a twofold increased risk of prostate cancer. Risk was more than twofold with the combination of mutant alleles of ER and CYP17. The PSA gene polymorphism did not show any increased risk of prostate cancer. This indicates the role of mutant allele of ER and CYP17 in the development and progression of prostate cancer and rules out any increased risk with PSA polymorphism in the north Indian population.
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Hurwitz M, Zheng H, Nagaraja G, Bausero M, Manola J, Kaur P, Asea A. Radiation Therapy Induces Circulating Serum Heat Shock Proteins in Prostate Cancer Patients: Clinical Findings and Laboratory Correlates. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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114
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Kaur P, Sharma P, Singh N, Sinha M, Jain R, Gopalakrishnapillai V, Kaur A, Sharma S, Alagiri S, Singh T. Crystal structure of complexes of peptidoglycan recognition protein with carbohydrates. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308088983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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115
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Sharma P, Singh N, Sinha M, Sharma S, Perbandt M, Betzel C, Kaur P, Srinivasan A, Singh T. Crystal structure of the peptidoglycan recognition protein at 1.8 Å resolution. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308089952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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116
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Dubey S, Kaur P, Jindal DP, Satyanarayan YD, Piplani P. Synthesis, evaluation and QSAR studies of 16-(4 & 3,4-substituted) benzylidene androstene derivatives as anticancer agents. Med Chem 2008; 4:229-36. [PMID: 18473915 DOI: 10.2174/157340608784325133] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In a systematic effort aimed at identifying new steroidal cytotoxic agents with potent antipoliferative activity against cancer cells and developing their QSAR models, series of 4-nitro, 4-isopropyl, 4-methoxy and 3,4-dimethoxy substituted benzylidene androst-5-ene derivatives were synthesized. The selected compounds were evaluated for antineoplastic activity against a panel of three human cell lines-breast, CNS and lungs at NCI, Bethesda, USA. The results presented herein reports that compounds 7, 9, 10, 15,16, 18, 20-25, 30, 32-36 and 44 have been found to be active anticancer agents. The QSAR of 20 compounds was performed separately for each cell line and best-fit QSAR models are developed. The QSAR models obtained have shown significant correlations (r(2) range: 0.9163 to 0.8164) and good predictive performance (q(2) range: 0.8499- 0.6320). The validation of models has also been performed using the test set of compounds 5, 15 and 44.
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Kaur P, Li CX, Barbetti MJ, You MP, Li H, Sivasithamparam K. First Report of Powdery Mildew Caused by Erysiphe cruciferarum on Brassica juncea in Australia. PLANT DISEASE 2008; 92:650. [PMID: 30769625 DOI: 10.1094/pdis-92-4-0650c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In Australia, Brassica juncea (L.) Czern & Coss (Indian mustard) has the potential as a more drought-tolerant oilseed crop than the B. napus L., with the first canola-quality B. juncea varieties released in Australia in 2006 and first sown for commercial production in 2007. Increased production of B. juncea is expected to result in the appearance of diseases previously unreported in Australia. In the spring of 2007 at the University of Western Australia field plots at Crawley (31.99°S, 115.82°E), Western Australia, plants of B. juncea genotypes from Australia and China had extensive stem colonization by powdery mildew at the end of the flowering period, with whitish patches ranging in size from 3 mm to 3 cm long. These patches coalesced to form a dense, white, powdery layer as they expanded. Pathogenicity was demonstrated by gently pressing infected stems containing abundant sporulation onto leaves of potted B. juncea seedlings of variety JM-18, incubating the plants in a moist chamber for 48 h, and then maintaining the plants in a controlled-environment room at 18/13°C for day/night. Signs of powdery mildew appeared at 7 days after inoculation, and by 10 days, it was well developed. Uninoculated control plants did not have powdery mildew. When symptomatic plants were examined, abundant conidia were typical of Erysiphe cruciferarum Opiz ex Junell, with cylindrical conidia borne singly or in short chains as described previously (2). Mycelia were amphigenous, in patches, and often spreading to become effused. Conidiophores were straight, foot cells were cylindrical, and conidia were mostly produced singly and measured 21.2 to 35.4 (mean 26.7 μm) × 8.8 to 15.9 μm (mean 11.9 μm) from measurements of 100 conidia. The spore size that we measured approximated what was found for E. cruciferarum (2) (30 to 40 × 12 to 16 μm), since we found 35 and 50% of spores falling within this range in terms of length and width, respectively. Conidia were, however, generally smaller in size than that reported on broccoli raab in California (1) (35 to 50 × 12 to 21 μm). We confirmed a length-to-width ratio greater than 2 as was found previously (1,2). Infected leaves showed signs of early senescence. While powdery mildew caused by E. cruciferarum is an important disease of B. juncea in India where yield losses as much as 17% have been reported (4), its potential impact in Australia is yet to be determined. To our knowledge, this is the first record of E. cruciferarum on B. juncea in Australia. In Western Australia, E. cruciferarum has been recorded on B. napus (oilseed rape) since 1986 and on B. napus L. var. napobrassica (L.) Reichenb. (swede) since 1971 (3). In other regions of Australia, it has been recorded on B. rapa in Queensland since 1913 and on B. napus (oilseed rape) in South Australia since 1973. References: (1) S. T. Koike and G. S. Saenz. Plant Dis. 81:1093, 1997. (2) T. J. Purnell and A. Sivanesan. No 251 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1970. (3) R. G. Shivas. J. R. Soc. West. Aust. 72:1, 1989. (4) A. K. Shukla et al. Manual on Management of Rapeseed-Mustard Diseases. National Research Centre on Rapeseed-Mustard, Bharatpur, India, 2003.
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Saravanan K, Hariprasad G, Jitesh O, Das U, Dey S, Sharma S, Kaur P, Singh TP, Srinivasan A. Endothelin and its receptor interactions: role of extracellular receptor domain and length of peptide ligands. Protein Pept Lett 2007; 14:779-83. [PMID: 17979818 DOI: 10.2174/092986607781483651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human endothelin B receptor and its domain-truncated forms were cloned and expressed in Pichia pastoris. Ligand binding studies with expressed proteins were carried out using biotinylated endothelins. Competitive binding and liposome incorporation studies showed that the extracellular region is essential for ligand binding and that longer peptides have higher affinity.
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Kaur P, Rao TV, Sankarasubbaiyan S, Narayanan AM, Ezhil R, Rao SR, Gupte MD. Prevalence and distribution of cardiovascular risk factors in an urban industrial population in south India: a cross-sectional study. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2007; 55:771-776. [PMID: 18290552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
BACKGROUND Cardiovascular diseases (CVD) are leading cause of death in developing countries including India. The huge burden of CVD in Indian subcontinent is the consequence of the large population and high prevalence of cardiovascular risk factors. This study was done to determine the prevalence of cardiovascular risk factors in two industrial units in Chennai, India. METHODS Survey of behavioural risk factors using structured questionnaires and anthropometric measurements were done for the study population. Blood samples were collected for the fasting plasma glucose and serum cholesterol. Trend chi-square was employed to test the linear trend. RESULTS The total study population included 2262 male subjects. Blood samples were collected for 2148 (95.0%) subjects. Age range was 18-69 years. Prevalence of major cardiovascular risk factors was: current smokers 462 (20.2%), body mass index > or = 23 kg/m2 1510 (66.8%), central obesity 1589 (70.2%), hypertension 615 (27.2%), diabetes mellitus 350(16.3%) and total cholesterol > or = 200mg/dl in 650(30.3%). CONCLUSIONS The study results indicated high prevalence of behavioural risk factors, central obesity, hypertension and diabetes in a select group of middle and high-income young urban males. The long-term follow-up in such settings will provide an opportunity to understand the influence of risk factors on cardiovascular disease outcomes.
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Sharma A, Kaur P, Kumar V, Gill KD. Attenuation of 1-methyl-4-phenyl-1, 2,3,6-tetrahydropyridine induced nigrostriatal toxicity in mice by N-acetyl cysteine. Cell Mol Biol (Noisy-le-grand) 2007; 53:48-55. [PMID: 17519111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Accepted: 11/15/2006] [Indexed: 05/15/2023]
Abstract
The present study was designed to investigate the effects of N-acetyl cysteine (NAC), an antioxidant on 1-methyl 4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) induced neurotoxicity in the nigrostriatal dopaminergic system of mice. MPTP treatment caused 80% decrease of the dopamine levels in the striatum of C57BL/ 6J mice. A marked increase in the extent of lipid peroxidation, superoxide dismutase (SOD) and g-glutamyl transpeptidase (g-GTP) was seen, while a significant decrease in the levels of glutathione (GSH), total thiols and glutathione peroxidase (GPx) activity was observed in the substantia nigra pars compacta (SNpc) of MPTP treated animals. As compared to control animals, Co-administration of NAC with MPTP restored the depleted dopamine, GSH, total tissue thiol levels and GPx activity in SNpc of treated mice brain. Moreover, NAC treatment also provided protection against lipid peroxidation and superoxide dismutase activity. The results of present study suggested that NAC attenuates MPTP neurotoxicity in mice brain and this protection by the NAC might be contributing to the regeneration of GSH, a major antioxidant.
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Kaur P, Semder C, Denning D, Korona M. P182. J Surg Res 2007. [DOI: 10.1016/j.jss.2006.12.518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Mishra S, Pertz V, Zhang B, Kaur P, Shimada H, Groffen J, Kazimierczuk Z, Pinna LA, Heisterkamp N. Treatment of P190 Bcr/Abl lymphoblastic leukemia cells with inhibitors of the serine/threonine kinase CK2. Leukemia 2006; 21:178-80. [PMID: 17082777 DOI: 10.1038/sj.leu.2404460] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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McClure RF, Kaur P, Pagel E, Ouillette PD, Holtegaard CE, Treptow CL, Kurtin PJ. Validation of immunoglobulin gene rearrangement detection by PCR using commercially available BIOMED-2 primers. Leukemia 2006; 20:176-9. [PMID: 16307010 DOI: 10.1038/sj.leu.2404049] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Jones K, Meldrum M, Baird E, Cottrell S, Kaur P, Plant N, Dyne D, Cocker J. Biological Monitoring for Trimethylbenzene Exposure: A Human Volunteer Study and a Practical Example in the Workplace. ACTA ACUST UNITED AC 2006; 50:593-8. [PMID: 16549407 DOI: 10.1093/annhyg/mel016] [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] [Indexed: 11/13/2022]
Abstract
This paper presents data from both a human volunteer study looking at exposure to 1,3,5-trimethylbenzene (TMB) and an occupational hygiene study of a printing firm using screen wash containing technical grade TMB. The biomarkers measured were TMB in blood and breath, and urinary dimethylbenzoic acids (DMBAs). The volunteer (N = 4) study showed that TMB was rapidly absorbed into the bloodstream reaching a mean level of 0.85 micromol l(-1) during a 4 h exposure to 25 p.p.m. TMB. There was little decline 1 h post-exposure possibly indicating storage of TMB in adipose tissue. Breath TMB levels peaked within an hour of exposure commencing and averaged 137 nmol l(-1) during exposure. Elimination of TMB in breath was biphasic with an initial half-life of 60 min. Peak excretion of urinary DMBA occurred 4-8 h after the end of exposure and averaged 40 mmol mol(-1) creatinine. Elimination of DMBA in urine was biphasic with half-lives of 13 and 60 h indicating that accumulation of body burden throughout the working week is likely if exposure is repeated. The occupational hygiene study demonstrated an excellent correlation between personal air TMB levels and post-shift urinary DMBA levels (r = 0.997) collected on the third working day. The regression equation from this study indicates that 8 h exposure to 25 p.p.m. TMB would result in a urinary DMBA level of 206 mmol mol(-1) creatinine. All workers showed pre-shift levels of DMBA from exposure to TMB on previous days. Both urinary DMBA and breath TMB levels can be used as biomarkers of TMB exposure. Urine samples should be taken post-shift towards the end of the working week as significant body burden accumulation throughout the working week can be expected. Breath sampling is more suited to task or single-shift monitoring.
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Jabeen T, Sharma S, Singh N, Singh RK, Kaur P, Perbandt M, Betzel C, Srinivasan A, Singh TP. Crystal structure of a calcium-induced dimer of two isoforms of cobra phospholipase A2 at 1.6 A resolution. Proteins 2006; 59:856-63. [PMID: 15828003 DOI: 10.1002/prot.20464] [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: 11/07/2022]
Abstract
The calcium-induced formation of a complex between two isoforms of cobra venom phospholipase A2 reveals a novel interplay between the monomer-dimer and activity-inactivity transitions. The monodispersed isoforms lack activity in the absence of calcium ions while both molecules gain activity in the presence of calcium ions. At concentrations higher than 10 mg/ml, in the presence of calcium ions, they dimerize and lose activity again. The present study reports the crystal structure of a calcium-induced dimer between two isoforms of cobra phospholipase A2. In the complex, one molecule contains a calcium ion in the calcium binding loop while the second molecule does not possess an intramolecular calcium ion. However, there are two calcium ions per dimer in the structure. The second calcium ion is present at an intermolecular site and that is presumably responsible for the dimerization. The calcium binding loops of the two molecules adopt strikingly different conformations. The so-called calcium binding loop in the calcium-containing molecule adopts a normal conformation as generally observed in other calcium containing phospholipase A(2) enzymes while the conformation of the corresponding loop in the calcium free monomer deviates considerably with the formation of a unique intraloop Gly33 (N)-Cys27 (O) = 2.74 A backbone hydrogen bond. The interactions of Arg31 (B) with Asp49 (A) and absence of calcium ion are responsible for the loss of catalytic activity in molecule A while interactions of Arg2 (B) with Tyr52 (B) inactivate molecule B.
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