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Patel V, Araya R, Chowdhary N, King M, Kirkwood B, Nayak S, Simon G, Weiss HA. Detecting common mental disorders in primary care in India: a comparison of five screening questionnaires. Psychol Med 2008; 38:221-8. [PMID: 18047768 PMCID: PMC4959557 DOI: 10.1017/s0033291707002334] [Citation(s) in RCA: 250] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Screening of patients for common mental disorders (CMDs) is needed in primary-care management programmes. This study aimed to compare the screening properties of five widely used questionnaires. METHOD Adult attenders in five primary-care settings in India were recruited through systematic sampling. Four questionnaires were administered, in pairs, in random order to participants: the General Health Questionnaire (GHQ, 12 items); the Primary Health Questionnaire (PHQ, nine items); the Kessler Psychological Distress Scale (K10, 10 items), and from which we could extract the score of the shorter 6-item K6; and the Self-Reporting Questionnaire (SRQ, 20 items). All participants were interviewed with a structured lay diagnostic interview, the Revised Clinical Interview Schedule (CIS-R). RESULTS Complete data were available for 598 participants (participation rate 99.3%). All five questionnaires showed moderate to high discriminating ability; the GHQ and SRQ showed the best results. All five showed moderate to high degrees of correlation with one another, the poorest being between the two shortest questionnaires, K6 and PHQ. All five had relatively good internal consistency. However, the positive predictive value (PPV) of the questionnaires compared with the diagnostic interview ranged from 51% to 77% at the optimal cut-off scores. CONCLUSIONS There is little difference in the ability of these questionnaires to identify cases accurately, but none showed high PPVs without a considerable compromise on sensitivity. Hence, the choice of an optimum cut-off score that yields the best balance between sensitivity and PPV may need to be tailored to individual settings, with a higher cut-off being recommended in resource-limited primary-care settings.
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Comparative Study |
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250 |
2
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Clifford R, Lee MH, Nayak S, Ohmachi M, Giorgini F, Schedl T. FOG-2, a novel F-box containing protein, associates with the GLD-1 RNA binding protein and directs male sex determination in the C. elegans hermaphrodite germline. Development 2000; 127:5265-76. [PMID: 11076749 DOI: 10.1242/dev.127.24.5265] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Male sex determination in the Caenorhabditis elegans hermaphrodite germline requires translational repression of tra-2 mRNA by the GLD-1 RNA binding protein. We cloned fog-2 by finding that its gene product physically interacts with GLD-1, forming a FOG-2/GLD-1/tra-2 3′untranslated region ternary complex. FOG-2 has an N-terminal F-box and a novel C-terminal domain called FTH. Canonical F-box proteins act as bridging components of the SCF ubiquitin ligase complex; the N-terminal F-box binds a Skp1 homolog, recruiting ubiquination machinery, while a C-terminal protein-protein interaction domain binds a specific substrate for degradation. However, since both fog-2 and gld-1 are necessary for spermatogenesis, FOG-2 cannot target GLD-1 for ubiquitin-mediated degradation. We propose that FOG-2 also acts as a bridge, bringing GLD-1 bound to tra-2 mRNA into a multiprotein translational repression complex, thus representing a novel function for an F-box protein. fog-2 is a member of a large, apparently rapidly evolving, C. elegans gene family that has expanded, in part, by local duplications; fog-2 related genes have not been found outside nematodes. fog-2 may have arisen during evolution of self-fertile hermaphroditism from an ancestral female/male species.
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121 |
3
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Schofield MJ, Nayak S, Scott TH, Du C, Hsieh P. Interaction of Escherichia coli MutS and MutL at a DNA Mismatch. J Biol Chem 2001; 276:28291-9. [PMID: 11371566 DOI: 10.1074/jbc.m103148200] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MutS and MutL are both required to activate downstream events in DNA mismatch repair. We examined the rate of dissociation of MutS from a mismatch using linear heteroduplex DNAs or heteroduplexes blocked at one or both ends by four-way DNA junctions in the presence and absence of MutL. In the presence of ATP, dissociation of MutS from linear heteroduplexes or heteroduplexes blocked at only one end occurs within 15 s. When both duplex ends are blocked, MutS remains associated with the DNA in complexes with half-lives of 30 min. DNase I footprinting of MutS complexes is consistent with migration of MutS throughout the DNA duplex region. When MutL is present, it associates with MutS and prevents ATP-dependent migration away from the mismatch in a manner that is dependent on the length of the heteroduplex. The rate and extent of mismatch-provoked cleavage at hemimethylated GATC sites by MutH in the presence of MutS, MutL, and ATP are the same whether the mismatch and GATC sites are in cis or in trans. These results suggest that a MutS-MutL complex in the vicinity of a mismatch is involved in activating MutH.
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Phipps JH, John M, Nayak S. Comparison of laparoscopically assisted vaginal hysterectomy and bilateral salpingo-oophorectomy with conventional abdominal hysterectomy and bilateral salpingo-oophorectomy. BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY 1993; 100:698-700. [PMID: 8080472 DOI: 10.1111/j.1471-0528.1993.tb14246.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Comparative Study |
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102 |
5
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Schofield MJ, Brownewell FE, Nayak S, Du C, Kool ET, Hsieh P. The Phe-X-Glu DNA binding motif of MutS. The role of hydrogen bonding in mismatch recognition. J Biol Chem 2001; 276:45505-8. [PMID: 11602569 DOI: 10.1074/jbc.c100449200] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The crystal structures of MutS protein from Thermus aquaticus and Escherichia coli in a complex with a mismatch-containing DNA duplex reveal that the Glu residue in a conserved Phe-X-Glu motif participates in a hydrogen-bonded contact with either an unpaired thymidine or the thymidine of a G-T base-base mismatch. Here, the role of hydrogen bonding in mismatch recognition by MutS is assessed. The relative affinities of MutS for DNA duplexes containing nonpolar shape mimics of A and T, 4-methylbenzimidazole (Z), and difluorotoluene (F), respectively, that lack hydrogen bonding donors and acceptors, are determined in gel mobility shift assays. The results provide support for an induced fit mode of mismatch binding in which duplexes destabilized by mismatches are preferred substrates for kinking by MutS. Hydrogen bonding between the O epsilon 2 group of Glu and the mismatched base contributes only marginally to mismatch recognition and is significantly less important than the aromatic ring stack with the conserved Phe residue. A MutS protein in which Ala is substituted for Glu(38) is shown to be defective for mismatch repair in vivo. DNA binding studies reveal a novel role for the conserved Glu residue in the establishment of mismatch discrimination by MutS.
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Puré E, Camp RL, Peritt D, Panettieri RA, Lazaar AL, Nayak S. Defective phosphorylation and hyaluronate binding of CD44 with point mutations in the cytoplasmic domain. J Exp Med 1995; 181:55-62. [PMID: 7528778 PMCID: PMC2191806 DOI: 10.1084/jem.181.1.55] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
CD44 is a cell surface adhesion molecule that plays a role in leukocyte extravasation, leukopoiesis, T lymphocyte activation, and tumor metastasis. The principal known ligand for CD44 is the glycosaminoglycan hyaluronate, (HA), a major constituent of extracellular matrices. CD44 expression is required but is not sufficient to confer cellular adhesion to HA, suggesting that the adhesion function of the receptor is regulated. We recently demonstrated that CD44 in primary leukocytes is phosphorylated in a cell type- and activation state-dependent fashion. In this study we demonstrate that serines 325 and 327 within the cytoplasmic domain of CD44 are required for the constitutive phosphorylation of CD44 in T cells. Furthermore, we demonstrate that cells expressing mutated CD44 containing a serine to glycine substitution at position 325 or a serine to alanine substitution at amino acid 327 are defective in HA binding, CD44-mediated adhesion of T cells to smooth muscle cells, as well as ligand-induced receptor modulation. The effect of these mutations can be partially reversed by a monoclonal anti-CD44 antibody that enhances CD44-mediated HA binding.
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research-article |
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Blanchette HA, Nayak S, Erasmus S. Comparison of the safety and efficacy of intravaginal misoprostol (prostaglandin E1) with those of dinoprostone (prostaglandin E2) for cervical ripening and induction of labor in a community hospital. Am J Obstet Gynecol 1999; 180:1551-9. [PMID: 10368503 DOI: 10.1016/s0002-9378(99)70051-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE This clinical trial evaluated the efficacy of intravaginal misoprostol (prostaglandin E1) and compared it with that of dinoprostone (prostaglandin E2) for cervical ripening and induction of labor in a community hospital. STUDY DESIGN This study involved a retrospective analysis of 81 patients undergoing cervical ripening and induction of labor with prostaglandin E2 from May 1, 1996, to May 1, 1997. A comparison prospective analysis of 145 patients undergoing the same procedure with prostaglandin E1 from May 1, 1997 to May 1, 1998, was performed. RESULTS The mean time to delivery was significantly shorter with misoprostol (19.8 +/- 10.4 hours) than with prostaglandin E2 (31.3 +/- 13.0 hours, P <.001). Delivery within 24 hours of induction was significantly more frequent with misoprostol (71.9% of subjects vs 31.3%, P <.001). There was no difference in the cesarean delivery rate with misoprostol (25.6% vs 22.2%, P <.67). The incidence of uterine hyperstimulation was higher with prostaglandin E2 (7.4% vs 0.7%, P <.007). There were no uterine ruptures with prostaglandin E2. There were 2 uterine ruptures and 1 dehiscence with prostaglandin E1 in 3 patients with previous cesarean deliveries and 1 rupture in a patient without a history of uterine scarring. There was no difference in neonatal outcome, with the exception of a fetal death related to uterine rupture in the misoprostol group. CONCLUSIONS Compared with prostaglandin E2, misoprostol is more effective in cervical ripening and induction of labor, is as safe for patients who do not have a history of cesarean birth, may carry a higher incidence of uterine rupture, and should not be used for patients attempting vaginal birth after previous cesarean delivery.
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Comparative Study |
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Janal MN, Raphael KG, Nayak S, Klausner J. Prevalence of myofascial temporomandibular disorder in US community women. J Oral Rehabil 2008; 35:801-9. [PMID: 18976276 DOI: 10.1111/j.1365-2842.2008.01854.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study estimates the prevalence of the myofascial subtype of temporomandibular disorders (M-TMD) defined by Research Diagnostic Criteria (RDC), and relates that prevalence to the surveyed report of facial pain. From among 20 000 women selected at random in the NY metropolitan area who completed a telephone survey of facial pain, 2000 were invited for an RDC/TMD examination; 782 examinations were completed. Prevalence was estimated in analyses that were weighted to correct sampling biases. Differences among demographic strata were evaluated with logistic regression. The prevalence of M-TMD was estimated to be 10.5% (95% CL = 8.5-13.0%). Prevalence was significantly higher among younger women, among women of lower socio-economic status, among Black women, and among non-Hispanic women. The report of facial pain in the telephone survey (10.1%) had high specificity for M-TMD diagnosis (94.7%), but low sensitivity (42.7%). M-TMD is a fairly common disorder among American women. Among those reporting facial pain during the last month, half met RDC palpation criteria for M-TMD; thus, a formal physical examination is imperative to establish this diagnosis. Prevalence varies with age, socio-economic status, race and Hispanic ethnicity. A substantial number of RDC-diagnosed cases of M-TMD did not report facial pain in the survey; the reason for this requires further study.
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Research Support, N.I.H., Extramural |
17 |
58 |
9
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O'Toole C, Nayak S, Price Z, Gilbert WH, Waisman J. A cell line (SCABER) derived from squamous cell carcinoma of the human urinary bladder. Int J Cancer 1976; 17:707-14. [PMID: 947851 DOI: 10.1002/ijc.2910170604] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
An established cell line derived from a documented squamous cell carcinoma of human urinary bladder is described. The cultured cells retained the characteristic morphology of the tumor of origin for 40 in vitro passages. Numerous desmosomes were found between cultured cells. Chromosome analysis showed hypotetraploidy with no obvious modal number, while distinctive marker chromosomes and a male karyotype were present.
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10
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Narayanan SN, Kumar RS, Potu BK, Nayak S, Mailankot M. Spatial memory performance of Wistar rats exposed to mobile phone. Clinics (Sao Paulo) 2009; 64:231-4. [PMID: 19330250 PMCID: PMC2666459 DOI: 10.1590/s1807-59322009000300014] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Accepted: 11/10/2008] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION With the tremendous increase in number of mobile phone users world wide, the possible risks of this technology have become a serious concern. OBJECTIVE We tested the effects of mobile phone exposure on spatial memory performance. MATERIALS AND METHODS Male Wistar rats (10-12 weeks old) were exposed to 50 missed calls/day for 4 weeks from a GSM (900/1800 MHz) mobile phone in vibratory mode (no ring tone). After the experimental period, the animals were tested for spatial memory performance using the Morris water maze test. RESULTS Both phone exposed and control animals showed a significant decrease in escape time with training. Phone exposed animals had significantly (approximately 3 times) higher mean latency to reach the target quadrant and spent significantly (approximately 2 times) less time in the target quadrant than age- and sex-matched controls. CONCLUSION Mobile phone exposure affected the acquisition of learned responses in Wistar rats. This in turn points to the poor spatial navigation and the object place configurations of the phone-exposed animals.
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research-article |
16 |
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11
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Nayak S, Cao O, Hoffman BE, Cooper M, Zhou S, Atkinson MA, Herzog RW. Prophylactic immune tolerance induced by changing the ratio of antigen-specific effector to regulatory T cells. J Thromb Haemost 2009; 7:1523-32. [PMID: 19583824 PMCID: PMC2981868 DOI: 10.1111/j.1538-7836.2009.03548.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Gene and protein replacement therapies for inherited protein deficiencies such as hemophilia or lysosomal storage disorders are limited by deleterious immune responses directed against their respective therapeutic proteins. Therefore, the development of protocols preventing such responses is key to providing successful long-term therapy. OBJECTIVES We sought to develop a protocol, utilizing a drug/peptide cocktail, that would effectively shift the antigen-specific CD4+ T-cell population, tipping the balance from effector T cells (Teffs) towards regulatory T cells (Tregs). METHODS Treg-deficient (DO11.10-tg Rag2(-/-)) BALB/c mice were used to screen for an optimal protocol addressing the aforementioned goal and to study the mechanisms underlying in vivo changes in T-cell populations. Muscle-directed gene transfer to hemophilia B mice was also performed in order to test the optimal protocol in a therapeutically relevant setting. RESULTS Specific antigen administration (4-week repeated dosing) combined with rapamycin and interleukin-10 led to substantial reductions in Teffs, via activation-induced cell death, and induced CD4+CD25+FoxP3+ Tregs to a large extent in multiple organs. The proportion of apoptotic T cells also increased over time, whereas Teffs and Tregs were differentially affected. When applied to a model of protein deficiency (gene therapy for hemophilia B), the protocol successfully prevented inhibitor formation, whereas non-specific immunosuppression was only marginally effective. CONCLUSIONS It is feasible to provide a short-term, prophylactic protocol allowing for the induction of immune tolerance. This protocol may provide a marked advance in efforts seeking to improve clinical outcomes in disorders involving therapeutic protein replacement.
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Research Support, N.I.H., Extramural |
16 |
56 |
12
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Galili N, Baldwin HS, Lund J, Reeves R, Gong W, Wang Z, Roe BA, Emanuel BS, Nayak S, Mickanin C, Budarf ML, Buck CA. A region of mouse chromosome 16 is syntenic to the DiGeorge, velocardiofacial syndrome minimal critical region. Genome Res 1997; 7:17-26. [PMID: 9037598 DOI: 10.1101/gr.7.1.17] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
DGS and VCFS, haploinsufficiencies characterized by multiple craniofacial and cardiac abnormalities, are associated with a microdeletion of chromosome 22q11.2. Here we document synteny between a 150-kb region on mouse chromosome 16 and the most commonly deleted portion of 22q11.2. Seven genes, all of which are transcribed in the early mouse embryo, have been identified. Of particular interest are two serine/threonine kinase genes and a novel goosecoid-like homeobox gene (Gscl). Comparative sequence analysis of a 38-kb segment reveals similarities in gene content, order, exon composition, and transcriptional direction. Therefore, if deletion of these genes results in DGS/VCFS in humans, then haploinsufficiencies involving this region of chromosome 16 should recapitulate the developmental field defects characteristic of this syndrome.
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Nayak S, Edwards DL, Saleh AA, Greenspan SL. Systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for osteoporosis or low bone density. Osteoporos Int 2015; 26:1543-54. [PMID: 25644147 PMCID: PMC4401628 DOI: 10.1007/s00198-015-3025-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 01/02/2015] [Indexed: 10/24/2022]
Abstract
UNLABELLED We performed a systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for DXA-determined osteoporosis or low bone density. Commonly evaluated risk instruments showed high sensitivity approaching or exceeding 90% at particular thresholds within various populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments. INTRODUCTION The purpose of the study is to systematically review the performance of clinical risk assessment instruments for screening for dual-energy X-ray absorptiometry (DXA)-determined osteoporosis or low bone density. METHODS Systematic review and meta-analysis were performed. Multiple literature sources were searched, and data extracted and analyzed from included references. RESULTS One hundred eight references met inclusion criteria. Studies assessed many instruments in 34 countries, most commonly the Osteoporosis Self-Assessment Tool (OST), the Simple Calculated Osteoporosis Risk Estimation (SCORE) instrument, the Osteoporosis Self-Assessment Tool for Asians (OSTA), the Osteoporosis Risk Assessment Instrument (ORAI), and body weight criteria. Meta-analyses of studies evaluating OST using a cutoff threshold of <1 to identify US postmenopausal women with osteoporosis at the femoral neck provided summary sensitivity and specificity estimates of 89% (95%CI 82-96%) and 41% (95%CI 23-59%), respectively. Meta-analyses of studies evaluating OST using a cutoff threshold of 3 to identify US men with osteoporosis at the femoral neck, total hip, or lumbar spine provided summary sensitivity and specificity estimates of 88% (95%CI 79-97%) and 55% (95%CI 42-68%), respectively. Frequently evaluated instruments each had thresholds and populations for which sensitivity for osteoporosis or low bone mass detection approached or exceeded 90% but always with a trade-off of relatively low specificity. CONCLUSIONS Commonly evaluated clinical risk assessment instruments each showed high sensitivity approaching or exceeding 90% for identifying individuals with DXA-determined osteoporosis or low BMD at certain thresholds in different populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments.
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Meta-Analysis |
10 |
54 |
14
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Nayak S, Shiflett SC, Schoenberger NE, Agostinelli S, Kirshblum S, Averill A, Cotter AC. Is acupuncture effective in treating chronic pain after spinal cord injury? Arch Phys Med Rehabil 2001; 82:1578-86. [PMID: 11689979 DOI: 10.1053/apmr.2001.26624] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES To evaluate the efficacy of acupuncture as a treatment for chronic pain and secondary symptoms after spinal cord injury (SCI) and to identify disease-specific variables associated with response to treatment. DESIGN A within-subjects design consisting of a 7(1/2)-week no-acupuncture baseline period followed by a 7(1/2)-week treatment period and a follow-up assessment 3 months posttreatment. SETTING Medical rehabilitation research center. PARTICIPANTS Twenty-two people with SCI who experienced moderate to severe pain of at least 6 months' duration. INTERVENTION A course of 15 acupuncture treatments was administered over a 7(1/2)-week period. MAIN OUTCOME MEASURES Numeric Rating Scale of pain intensity; ratings of interference with activity, individualized symptom rating, Center for Epidemiologic Studies-Depression Scale; Speilberger State Trait Anxiety Inventory, and General Well-Being Schedule. RESULTS Ten patients (46%) showed improvement in pain intensity and pain sequelae after treatment. However, 6 patients (27%) reported an increase in pain that was still present 3 months after treatment. CONCLUSIONS About 50% of the study sample reported substantial pain relief after acupuncture treatment, suggesting that acupuncture may provide pain relief for at least a subgroup of individuals with SCI. Future research is needed to determine what part of this effect is because of acupuncture versus nonspecific effects such as placebo effects and regression to the mean.
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15
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Narayanan SN, Kumar RS, Potu BK, Nayak S, Bhat PG, Mailankot M. Effect of radio-frequency electromagnetic radiations (RF-EMR) on passive avoidance behaviour and hippocampal morphology in Wistar rats. Ups J Med Sci 2010; 115:91-6. [PMID: 20095879 PMCID: PMC2853785 DOI: 10.3109/03009730903552661] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
INTRODUCTION The interaction of mobile phone radio-frequency electromagnetic radiation (RF-EMR) with the brain is a serious concern of our society. OBJECTIVE We evaluated the effect of RF-EMR from mobile phones on passive avoidance behaviour and hippocampal morphology in rats. MATERIALS AND METHODS Healthy male albino Wistar rats were exposed to RF-EMR by giving 50 missed calls (within 1 hour) per day for 4 weeks, keeping a GSM (0.9 GHz/1.8 GHz) mobile phone in vibratory mode (no ring tone) in the cage. After the experimental period, passive avoidance behaviour and hippocampal morphology were studied. RESULTS Passive avoidance behaviour was significantly affected in mobile phone RF-EMR-exposed rats demonstrated as shorter entrance latency to the dark compartment when compared to the control rats. Marked morphological changes were also observed in the CA(3) region of the hippocampus of the mobile phone-exposed rats in comparison to the control rats. CONCLUSION Mobile phone RF-EMR exposure significantly altered the passive avoidance behaviour and hippocampal morphology in rats.
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research-article |
15 |
48 |
16
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Persson K, Gingerich RL, Nayak S, Wada K, Wada E, Ahrén B. Reduced GLP-1 and insulin responses and glucose intolerance after gastric glucose in GRP receptor-deleted mice. Am J Physiol Endocrinol Metab 2000; 279:E956-62. [PMID: 11052949 DOI: 10.1152/ajpendo.2000.279.5.e956] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
By applying a newly developed ELISA technique for determining biologically active intact glucagon-like peptide [GLP-1, GLP-1-(7-36)amide] in mouse, plasma baseline GLP-1 in normal NMRI mice was found to be normally distributed (4.5 +/- 0.3 pmol/l; n = 72). In anesthetized mice, gastric glucose (50 or 150 mg) increased plasma GLP-1 levels two- to threefold (P < 0.01). The simultaneous increase in plasma insulin correlated to the 10-min GLP-1 levels (r = 0.36, P < 0.001; n = 12). C57BL/6J mice deleted of the gastrin-releasing peptide (GRP) receptor by genetic targeting had impaired glucose tolerance (P = 0.030) and reduced early (10 min) insulin response (P = 0.044) to gastric glucose compared with wild-type controls. Also, the GLP-1 response to gastric glucose was significantly lower in the GRP receptor-deleted mice than in the controls (P = 0.045). In conclusion, this study has shown that 1) plasma levels of intact GLP-1 increase dose dependently on gastric glucose challenge in correlation with increased insulin levels in mice, and 2) intact GRP receptors are required for normal GLP-1 and insulin responses and glucose tolerance after gastric glucose in mice.
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Nayak S, Matheis RJ, Agostinelli S, Shifleft SC. The use of complementary and alternative therapies for chronic pain following spinal cord injury: a pilot survey. J Spinal Cord Med 2002; 24:54-62. [PMID: 11587436 DOI: 10.1080/10790268.2001.11753556] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVE The purpose of this study was to determine the patterns and reasons for the use of complementary and alternative medicine (CAM) as a treatment for chronic pain among individuals with spinal cord injuries (SCI). METHODS Telephone surveys were conducted in a sample of 77 people with SCI and chronic pain. RESULTS Of those surveyed, 40.3% had used at least one CAM technique to manage chronic pain. The most common reason was dissatisfaction with conventional medicine. Acupuncture was the most frequently used modality, followed by massage, chiropractic manipulation, and herbal medicine. Acupuncture was rated lowest for satisfaction with pain relief, and massage was rated highest. Individuals not using conventional pain medication or who desired greater control over their health care practices tended to use more CAM techniques than others. Income, insurance coverage, and duration of pain were related to use of CAM. In general, CAM methods were effective for some and totally ineffective for others, indicating selective utility in this population. CONCLUSIONS Despite this small opportunistic sample, the prevalence of CAM among individuals with SCI appears similar to that in the general population. A placebo-controlled trial is needed to evaluate the efficacy of various therapies in the SCI population. The fact that the most effective therapy, massage, was not frequently used suggests the need for more awareness of and research into this technique.
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Joshi RK, Nayak S. Functional characterization and signal transduction ability of nucleotide-binding site-leucine-rich repeat resistance genes in plants. GENETICS AND MOLECULAR RESEARCH 2011; 10:2637-52. [PMID: 22057959 DOI: 10.4238/2011.october.25.10] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Pathogen infection in plants is often limited by a multifaceted defense response triggered by resistance genes. The most prevalent class of resistance proteins includes those that contain a nucleotide-binding site-leucine-rich repeat (NBS-LRR) domain. Over the past 15 years, more than 50 novel NBS-LRR class resistance genes have been isolated and characterized; they play a significant role in activating conserved defense-signaling networks. Recent molecular research on NBS-LRR resistance proteins and their signaling networks has the potential to broaden the use of resistance genes for disease control. Various transgenic approaches have been tested to broaden the disease resistance spectrum using NBS-LRR genes. This review highlights the recent progress in understanding the structure, function, signal transduction ability of NBS-LRR resistance genes in different host-pathogen systems and suggests new strategies for engineering pathogen resistance in crop plants.
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Review |
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42 |
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Narayanan SN, Jetti R, Kesari KK, Kumar RS, Nayak SB, Bhat PG. Radiofrequency electromagnetic radiation-induced behavioral changes and their possible basis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:30693-30710. [PMID: 31463749 DOI: 10.1007/s11356-019-06278-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 08/16/2019] [Indexed: 06/10/2023]
Abstract
The primary objective of mobile phone technology is to achieve communication with any person at any place and time. In the modern era, it is impossible to ignore the usefulness of mobile phone technology in cases of emergency as many lives have been saved. However, the biological effects they may have on humans and other animals have been largely ignored and not been evaluated comprehensively. One of the reasons for this is the speedy uncontrollable growth of this technology which has surpassed our researching ability. Initiated with the first generation, the mobile telephony currently reaches to its fifth generation without being screened extensively for any biological effects that they may have on humans or on other animals. Mounting evidences suggest possible non-thermal biological effects of radiofrequency electromagnetic radiation (RF-EMR) on brain and behavior. Behavioral studies have particularly concentrated on the effects of RF-EMR on learning, memory, anxiety, and locomotion. The literature analysis on behavioral effects of RF-EMR demonstrates complex picture with conflicting observations. Nonetheless, numerous reports suggest a possible behavioral effect of RF-EMR. The scientific findings about this issue are presented in the current review. The possible neural and molecular mechanisms for the behavioral effects have been proposed in the light of available evidences from the literature.
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Review |
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Samples JR, Binder PS, Nayak S. The effect of epinephrine and benzalkonium chloride on cultured corneal endothelial and trabecular meshwork cells. Exp Eye Res 1989; 49:1-12. [PMID: 2759185 DOI: 10.1016/0014-4835(89)90071-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We evaluated the effect of dipivefrin hydrochloride, epinephrine hydrochloride, epinephrine borate and their respective vehicles with and without the preservative benzalkonium chloride, on the in vitro growth characteristics of human corneal keratocytes, endothelial cells and trabecular meshwork. Epinephrine hydrochloride and borate at low concentrations (0.0002%) significantly inhibited growth of both trabecular meshwork and corneal endothelial cells. Higher concentrations (0.02%) of these same drugs induced the same effect on the growth of keratocytes in vitro. Similar observations were made on the effect of dipivefrin hydrochloride on human corneal cells in vitro. Benzalkonium chloride alone was demonstrated to be responsible for the growth inhibitory effects on trabecular cells. The susceptibility of trabecular meshwork cells in culture to the commonly used ophthalmic preservative benzalkonium chloride is demonstrated.
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Williams KV, Nayak S, Becker D, Reyes J, Burmeister LA. Fifty years of experience with propylthiouracil-associated hepatotoxicity: what have we learned? J Clin Endocrinol Metab 1997; 82:1727-33. [PMID: 9177371 DOI: 10.1210/jcem.82.6.4011] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The aim of this study was to determine the optimal management of patients with propylthiouracil (PTU) hepatotoxicity. A MEDLINE search for English language cases of PTU hepatotoxicity between 1966 and April 1996 was performed, and additional cases were cross-referenced. Twenty-seven cases were selected based on the availability of information on patient management after the onset of hepatotoxicity. Eighty-five percent of the selected cases met this criterion. A detailed summary of the management of two cases of PTU hepatotoxicity at our institutions is also provided. Although most patients recovered once PTU was stopped, seven patients died. Patients with PTU hepatotoxicity who survived were more likely to have received 131I during the course of their illness than those who died (P < 0.03, by Fisher's exact test). In our two patients, hyperbilirubinemia was linearly associated with progressively decreasing T4 levels (r = 0.91; P < 0.001) despite the presence of clinical thyrotoxicosis in one of the patients. These findings demonstrate the need for appropriate clinical evaluation and treatment of thyroid disease during the course of hepatotoxicity. Additionally, we report the first pediatric patient with PTU hepatotoxicity to undergo liver transplantation. The emerging role of liver transplantation in these patients is discussed.
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Case Reports |
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Abstract
Sinus histiocytosis with massive lymphadenopathy (SHML) is a benign, self-limiting condition of unknown etiology, which generally presents as massive bilateral cervical lymphadenopathy. It is important to distinguish SHML from other causes of histiocytosis because of the different treatment modalities. This study was carried out to assess the utility of fine-needle aspiration cytology (FNAC) findings in SHML and to distinguish if from other reactive lymphadenopathies. The lymph nodes in 4 patients (3 male and 1 female) presenting with massive bilateral cervical lymphadenopathy were aspirated. All presented with persistent bilateral cervical lymphadenopathy, polymorphnuclear leukocytosis, and raised erythrocyte sedimentation rate (ESR). Smears showed a reactive lymphoid population consisting of mature lymphocytes, plasma cells, a few polymorphs, and many histiocytes showing emperipolesis. Based on the cytologic and clinical findings, a diagnosis of SHML was made. Histopathology confirmed the diagnosis in all cases. A conclusive diagnosis of SHML can be based on cytology, provided that the cytologic findings are interpreted in the appropriate clinical context. Biopsy can be avoided in these patients. Diagn. Cytopathol. 2000;22:181-185.
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Case Reports |
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Nayak S, Lee PA, Witchel SF. Variants of the type II 3beta-hydroxysteroid dehydrogenase gene in children with premature pubic hair and hyperandrogenic adolescents. Mol Genet Metab 1998; 64:184-92. [PMID: 9719627 DOI: 10.1006/mgme.1998.2715] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To ascertain the potential role of heterozygosity for 3beta-hydroxysteroid (3beta-HSD) deficiency in children with premature pubic hair and adolescent girls with hyperandrogenism, we performed single-strand conformational polymorphism (SSCP) analysis of the 3beta-hydroxysteroid dehydrogenase type 2 (3beta-HSD2) gene in 34 hyperandrogenic patients. Three sequence variants, two missense mutations and a 3'-UTR sequence variant, were detected among seven patients and in none of 100 healthy control subjects. One of these seven patients carried Leu236 --> Ser on one 3beta-HSD2 allele and Glu318 --> STOP on one 21-hydroxylase (CYP21) allele. ACTH stimulation tests were performed in 5/7 patients with sequence variants and were compatible with decreased 3beta-hydroxysteroid dehydrogenase activity in three. Thus, 7 of 34 (20.6%) mildly hyperandrogenic patients carry heterozygous sequence variants of the 3beta-HSD2 gene. Since obligate heterozygotic carriers for congenital adrenal hyperplasia are typically asymptomatic, other genetic or environmental influences may contribute to the expression of hyperandrogenic symptoms in our patients.
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Nayak S, Greenspan SL. A systematic review and meta-analysis of the effect of bisphosphonate drug holidays on bone mineral density and osteoporotic fracture risk. Osteoporos Int 2019; 30:705-720. [PMID: 30623214 PMCID: PMC6499675 DOI: 10.1007/s00198-018-4791-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/19/2018] [Accepted: 11/25/2018] [Indexed: 10/27/2022]
Abstract
UNLABELLED We performed a systematic review on the effect of drug holidays (discontinuation) on bone mineral density (BMD) and fracture risk. Bisphosphonate discontinuation may be considered for women who do not have low hip BMD after 3-5 years of initial treatment, while women who have low hip BMD may benefit from treatment continuation. INTRODUCTION We performed a systematic review and meta-analysis on the effect of drug holidays (discontinuation) on BMD and fracture risk. METHODS We searched PubMed, Embase, and Cochrane Library databases to locate controlled clinical trials and cohort studies evaluating the effect of drug holidays/discontinuation versus osteoporosis treatment continuation. We performed random-effects meta-analyses of hazard ratios of hip and any clinical osteoporotic fracture for individuals who discontinued bisphosphonates compared to persistent users. RESULTS Thirteen records reporting results from eight different studies met inclusion criteria. The FLEX study found a reduced clinical vertebral fracture risk with 10 years of alendronate therapy compared to 5 (RR 0.45, 95% CI 0.24-0.85), and the HORIZON extension studies found a reduced risk of morphometric vertebral fracture with 6 years of zoledronic acid therapy compared to 3 (OR = 0.51, 95% CI 0.26-0.95); subgroup analyses showed that women with low hip BMD T-scores after the initial treatment period benefitted from continued treatment in terms of reduced vertebral fracture risk. Meta-analysis of adjusted hazard ratios of hip and any clinical osteoporotic fracture for women who discontinued bisphosphonates revealed no significant differences in the risk of hip fracture (summary estimate of HR 1.09, 95% CI 0.87-1.37) or any clinical fracture (summary estimate of HR 1.13, 95% CI 0.75-1.70) compared to persistent users. CONCLUSIONS Bisphosphonate discontinuation may be considered for women who do not have low hip BMD after 3 to 5 years of initial treatment, while women who have low hip BMD may benefit from treatment continuation.
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Meta-Analysis |
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Nayak S, Edwards DL, Saleh AA, Greenspan SL. Performance of risk assessment instruments for predicting osteoporotic fracture risk: a systematic review. Osteoporos Int 2014; 25:23-49. [PMID: 24105431 PMCID: PMC3962543 DOI: 10.1007/s00198-013-2504-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 08/19/2013] [Indexed: 10/26/2022]
Abstract
UNLABELLED We systematically reviewed the literature on the performance of osteoporosis absolute fracture risk assessment instruments. Relatively few studies have evaluated the calibration of instruments in populations separate from their development cohorts, and findings are mixed. Many studies had methodological limitations making susceptibility to bias a concern. INTRODUCTION The aim of this study was to systematically review the literature on the performance of osteoporosis clinical fracture risk assessment instruments for predicting absolute fracture risk, or calibration, in populations other than their derivation cohorts. METHODS We performed a systematic review, and MEDLINE, Embase, Cochrane Library, and multiple other literature sources were searched. Inclusion and exclusion criteria were applied and data extracted, including information about study participants, study design, potential sources of bias, and predicted and observed fracture probabilities. RESULTS A total of 19,949 unique records were identified for review. Fourteen studies met inclusion criteria. There was substantial heterogeneity among included studies. Six studies assessed the WHO's Fracture Risk Assessment (FRAX) instrument in five separate cohorts, and a variety of risk assessment instruments were evaluated in the remainder of the studies. Approximately half found good instrument calibration, with observed fracture probabilities being close to predicted probabilities for different risk categories. Studies that assessed the calibration of FRAX found mixed performance in different populations. A similar proportion of studies that evaluated simple risk assessment instruments (≤5 variables) found good calibration when compared with studies that assessed complex instruments (>5 variables). Many studies had methodological features making them susceptible to bias. CONCLUSIONS Few studies have evaluated the performance or calibration of osteoporosis fracture risk assessment instruments in populations separate from their development cohorts. Findings are mixed, and many studies had methodological limitations making susceptibility to bias a possibility, raising concerns about use of these tools outside of the original derivation cohorts. Further studies are needed to assess the calibration of instruments in different populations prior to widespread use.
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Research Support, N.I.H., Extramural |
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