19 results on '"N. Chanana"'
Search Results
2. CCR2-CCL2 Axis in Hypoxic Pulmonary Hypertension
- Author
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R. Kumar, B. Kassa, N. Chanana, K. Sharma, T. Palmo, S. Kumar, C. Mickael, M.H. Lee, K.R. Stenmark, R.M. Tuder, Q. Pasha, and B.B. Graham
- Published
- 2022
- Full Text
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3. Immune consequences of exercise in hypoxia: A narrative review.
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Burtscher J, Pasha Q, Chanana N, Millet GP, Burtscher M, and Strasser B
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- Humans, Immunity, Innate physiology, Altitude, Oxygen metabolism, Acclimatization physiology, Immune System physiology, Adaptation, Physiological, Exercise physiology, Hypoxia immunology, Adaptive Immunity
- Abstract
Immune outcomes are key mediators of many health benefits of exercise and are determined by exercise type, dose (frequency/duration, intensity), and individual characteristics. Similarly, reduced availability of ambient oxygen (hypoxia) modulates immune functions depending on the hypoxic dose and the individual capacity to respond to hypoxia. How combined exercise and hypoxia (e.g., high-altitude training) sculpts immune responses is not well understood, although such combinations are becoming increasingly popular. Therefore, in this paper, we summarize the impact on immune responses of exercise and of hypoxia, both independently and together, with a focus on specialized cells in the innate and adaptive immune system. We review the regulation of the immune system by tissue oxygen levels and the overlapping and distinct immune responses related to exercise and hypoxia, then we discuss how they may be modulated by nutritional strategies. Mitochondrial, antioxidant, and anti-inflammatory mechanisms underlie many of the adaptations that can lead to improved cellular metabolism, resilience, and overall immune functions by regulating the survival, differentiation, activation, and migration of immune cells. This review shows that exercise and hypoxia can impair or complement/synergize with each other while regulating immune system functions. Appropriate acclimatization, training, and nutritional strategies can be used to avoid risks and tap into the synergistic potentials of the poorly studied immune consequences of exercising in a hypoxic state., (Copyright © 2023. Production and hosting by Elsevier B.V.)
- Published
- 2024
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4. Dexamethasone prophylaxis protects from acute high-altitude illness by modifying the peripheral blood mononuclear cell inflammatory transcriptome.
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Kumar R, Chanana N, Sharma K, Palmo T, Lee MH, Mishra A, Nolan K, Fonseca Balladares DC, Mickael C, Gupta MD, Thinlas T, Pasha Q, and Graham BB
- Subjects
- Humans, Altitude, Inflammation, Transcriptome, Dexamethasone pharmacology, Leukocytes, Mononuclear
- Abstract
Acute high-altitude (HA) exposure can induce several pathologies. Dexamethasone (DEX) can be taken prophylactically to prevent HA disease, but the mechanism by which it acts in this setting is unclear. We studied the transcriptome of peripheral blood mononuclear cells (PBMCs) from 16 subjects at low altitude (LA, 225 m) and then 3 days after acute travel to HA (3500 m) during the India-Leh-Dexamethasone-Expedition-2020 (INDEX2020). Half of the participants received oral DEX prophylaxis 4 mg twice daily in an unblinded manner, starting 1 day prior to travel to HA, and 12 h prior to the first PBMC collection. PBMC transcriptome data were obtained from 16 subjects, half of whom received DEX. The principal component analysis demonstrated a clear separation of the groups by altitude and treatment. HA exposure resulted in a large number of gene expression changes, particularly in pathways of inflammation or the regulation of cell division, translation, or transcription. DEX prophylaxis resulted in changes in fewer genes, particularly in immune pathways. The gene sets modulated by HA and DEX were distinct. Deconvolution analysis to assess PBMC subpopulations suggested changes in B-cell, T-cell, dendritic cell, and myeloid cell numbers with HA and DEX exposures. Acute HA travel and DEX prophylaxis induce significant changes in the PBMC transcriptome. The observed benefit of DEX prophylaxis against HA disease may be mediated by suppression of inflammatory pathways and changing leukocyte population distributions., (© 2023 The Author(s).)
- Published
- 2023
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5. Disparities in COVID-19 incidence and fatality rates at high-altitude.
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Abbasi BA, Chanana N, Palmo T, and Pasha Q
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- Humans, SARS-CoV-2, Incidence, Altitude, Hypoxia epidemiology, COVID-19 epidemiology, Diabetes Mellitus
- Abstract
Background: SARS-CoV-2 has affected every demography disproportionately, including even the native highland populations. Hypobaric-hypoxic settings at high-altitude (HA, >2,500 masl) present an extreme environment that impacts the survival of permanent residents, possibly including SARS-CoV-2. Conflicting hypotheses have been presented for COVID-19 incidence and fatality at HA., Objectives: To evaluate protection or risk against COVID-19 incidence and fatality in humans under hypobaric-hypoxic environment of high-altitude (>2,501 masl)., Methods: Global COVID-19 data of March 2020-21, employed from official websites of the Indian Government, John Hopkins University, and Worldometer were clustered into 6 altitude categories. Clinical cofactors and comorbidities data were evaluated with COVID-19 incidence and fatality. Extensive comparisons and correlations using several statistical tools estimated the risk and protection., Results: Of relevance, data analyses revealed four distinct responses, namely, partial risk, total risk, partial protection, and total protection from COVID-19 at high-altitude indicating a mixed baggage and complexity of the infection. Surprisingly, it included the countries within the same geographic region. Moreover, body mass index, hypertension, and diabetes correlated significantly with COVID-19 incidence and fatality rate ( P ≤ 0.05)., Conclusions: Varied patterns of protection and risk against COVID-19 incidence and fatality were observed among the high-altitude populations. It is though premature to generalize COVID-19 effects on any particular demography without further extensive studies., Competing Interests: The authors declare there are no competing interests., (©2023 Abbasi et al.)
- Published
- 2023
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6. The EDN1 Missense Variant rs5370 G > T Regulates Adaptation and Maladaptation under Hypobaric Hypoxia.
- Author
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Palmo T, Abbasi BA, Chanana N, Sharma K, Faruq M, Thinlas T, Abdin MZ, and Pasha Q
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- Altitude, Case-Control Studies, Humans, Hypoxia metabolism, Vasoconstrictor Agents, Altitude Sickness genetics, Endothelin-1 genetics
- Abstract
Endothelin 1 ( EDN1 ) encodes a potent endogenous vasoconstrictor, ET1, to maintain vascular homeostasis and redistribution of tissue blood flow during exercise. One of the EDN1 missense polymorphisms, rs5370 G/T , has strongly been associated with cardiopulmonary diseases. This study investigated the impact of rs5370 polymorphism in high-altitude pulmonary oedema (HAPE) disorder or maladaptation and adaptation physiology in a well-characterized case-control study of high-altitude and low-altitude populations comprising 310 samples each of HAPE-patients, HAPE-free controls and native highlanders. The rs5370 polymorphism was genotyped, and the gene expression and plasma level of EDN1 were evaluated. The functional relevance of each allele was investigated in the human embryonic kidney 293 cell line after exposure to hypoxia and computationally. The T allele was significantly more prevalent in HAPE-p compared to HAPE-f and HLs. The EDN1 gene expression and ET1 bio-level were significantly elevated in HAPE-p compared to controls. Compared to the G allele, the T allele was significantly associated with elevated levels of ET-1 in all three study groups and cells exposed to hypoxia. The in silico studies further confirmed the stabilizing effect of the T allele on the structural integrity and function of ET1 protein. The ET1 rs5370 T allele is associated with an increased concentration of ET-1 in vivo and in vitro, establishing it as a potent marker in the adaptation/maladaptation physiology under the high-altitude environment. This could also be pertinent in endurance exercises at high altitudes.
- Published
- 2022
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7. Sexual Dimorphism of Dexamethasone as a Prophylactic Treatment in Pathologies Associated With Acute Hypobaric Hypoxia Exposure.
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Chanana N, Palmo T, Sharma K, Kumar R, Shah B, Mahajan S, Palleda GM, Gupta MD, Kukreti R, Faruq M, Thinlas T, Graham BB, and Pasha Q
- Abstract
Dexamethasone can be taken prophylactically to prevent hypobaric hypoxia-associated disorders of high-altitude. While dexamethasone-mediated protection against high-altitude disorders has been clinically evaluated, detailed sex-based mechanistic insights have not been explored. As part of our India-Leh-Dexamethasone-expedition-2020 (INDEX 2020) programme, we examined the phenotype of control ( n = 14) and dexamethasone ( n = 13) groups, which were airlifted from Delhi (∼225 m elevation) to Leh, Ladakh (∼3,500 m), India, for 3 days. Dexamethasone 4 mg twice daily significantly attenuated the rise in blood pressure, heart rate, pulmonary pressure, and drop in SaO
2 resulting from high-altitude exposure compared to control-treated subjects. Of note, the effect of dexamethasone was substantially greater in women than in men, in whom the drug had relatively little effect. Thus, for the first time, this study shows a sex-biased regulation by dexamethasone of physiologic parameters resulting from the hypoxic environment of high-altitude, which impacts the development of high-altitude pulmonary hypertension and acute mountain sickness. Future studies of cellular contributions toward sex-specific regulation may provide further insights and preventive measures in managing sex-specific, high-altitude-related disorders., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chanana, Palmo, Sharma, Kumar, Shah, Mahajan, Palleda, Gupta, Kukreti, Faruq, Thinlas, Graham and Pasha.)- Published
- 2022
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8. Opioid sparing strategies for perioperative pain management other than regional anaesthesia: A narrative review.
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Ghai B, Jafra A, Bhatia N, Chanana N, Bansal D, and Mehta V
- Abstract
Opioids play a crucial role in pain management in spite of causing increased hospital morbidity and related costs. It may also cause significant risks such as postoperative nausea and vomiting (PONV), sedation, sleep disturbances, urinary retention and respiratory depression (commonly referred to as opioid related adverse effects) in postoperative patients. In order to evade these opioid related side effects and also improve pain management, multimodal analgesia i.e., combination of different analgesics, was introduced more than a decade ago. Both pharmacological and non-pharmacological techniques are available as opioid sparing analgesia. Research from around the world have proved pharmacological techniques ranging from acetaminophen, NSAIDs (non-steroidal anti-inflammatory drugs), N-methyl-D-aspartate receptor antagonists (NDMA), alpha-2 agonists, anticonvulsants such as gamma aminobutyric acid analogues, beta-blockers, capsaicin, lignocaine infusion to glucocorticoids to be effective. On the other hand, non-pharmacological methods include techniques such as cognitive behavioral therapy, transcutaneous electrical nerve stimulation (TENS), electroanalgesia, acupuncture and hypnosis. However, research regarding the effect of these non-pharmacological techniques on pain management is still needed., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Journal of Anaesthesiology Clinical Pharmacology.)
- Published
- 2022
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9. Employee engagement practices during COVID-19 lockdown.
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Chanana N and Sangeeta
- Abstract
In the present business situation during the COVID-19 pandemic, employee engagement has become one of the utmost prominent primacies for human resource managers and practitioners in organizations due to lockdown. The paper is to determine the engagement of employees by various companies during coronavirus pandemic. Organizations nowadays are constantly developing innovative and effective means to engage the employees during this tough time. This paper is a conceptual paper that is based on various research papers, articles, blogs, online newspapers, and reports of World Health Organization. During this pandemic situation, organizations are evolving many engagement activities like online family engagement practices, virtual learning and development, online team building activities, webinars with industry experts, online conduct weekly alignment sessions, team meet-ups over video conference for lunch, short online game sessions, virtual challenges and competitions, online courses, appreciation sessions, communication exercises, live sessions for new-skill training, online counseling sessions, recognition and acknowledgment session, webinars dealing with anxiety and stress, providing online guidance for exercise and meditation, social interactions in a virtual office, classrooms training modules digitally, e-learning modules, and many more creative learning sessions. Work-from-home regime engagement activities are very fruitful for employees as well as for organizations. Those organizations doing these kinds of engagement activities for their employees are learning new skills and developing themselves. Employees are feeling committed to the organization and stay motivated during this tough time of COVID-19 pandemic., (© 2020 John Wiley & Sons Ltd.)
- Published
- 2021
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10. The impact of COVID-19 pandemic on employees organizational commitment and job satisfaction in reference to gender differences.
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Chanana N
- Abstract
In this study, an attempt has been made to examine the level of organizational commitment and job satisfaction among male and female school teachers working in private schools during the Covid-19 pandemic. For the present study, descriptive method is used. The sample of 181 private school teachers was drawn using a purposive sampling procedure. The organizational commitment questionnaire is developed by Allen and Meyer in 1990 and job satisfaction index by Brayfield and Rothe in 1951 is used for the study. For descriptive statistics mean, standard deviation (S.D.), and z test is used. Shapiro-Wilks test, Levene's test, and Mann-Whitney U test is used to analyze data in the current study. The results revealed that female teachers are more continuance committed as compared to male teachers during this tough situation of a pandemic. The level of organizational commitment is found low in both female and male teachers during the Covid-19. No significant difference is found in the overall job satisfaction among male and female teachers during the Covid-19 pandemic. This study also determines a positive and significant relationship between organizational commitment and job satisfaction during the Covid-19 pandemic., (© 2021 John Wiley & Sons Ltd.)
- Published
- 2021
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11. Hypertensive Patients Exhibit Enhanced Thrombospondin-1 Levels at High-Altitude.
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Sharma K, Chanana N, Mohammad G, Thinlas T, Gupta M, Syed MA, Das RS, Pasha Q, and Mishra A
- Abstract
Thrombospondin-1 (THBS1) levels elevate under hypoxia and have relevance in several cardiovascular disorders. The association of THBS1 with endothelial dysfunction implies its important role in hypertension. To establish the hypothesis, we screened patients with hypertension and their respective controls from the two different environmental regions. Cohort 1 was composed of Ladakhis, residing at 3500 m above sea level (ASL), whereas Cohort 2 was composed of north-Indians residing at ~200 m ASL. Clinical parameters and circulating THBS1 levels were correlated in the case-control groups of the two populations. THBS1 levels were significantly elevated in hypertension patients of both cohorts; however, the levels were distinctly enhanced in the hypertensive patients of HA as compared to normoxia ( p < 0.002). The observation was supported by the receiver operating curve analysis with an area under curve of 0.7007 (0.627-0.774) demonstrating the discriminatory effect of hypobaric hypoxia on the levels as compared to normoxia ( p < 0.011). Significant correlation of THBS1 and mean arterial pressure was observed with upraised positive correlations in the hypertensive highlanders as compared to the hypertensive patients from sea-level. The prevalence of differential distribution of THBS1 and CD47 genes variants, their interactions, and association with the THBS1 levels were also determined. Genotype-interactions between THBS1 rs2228263 and CD47 rs9879947 were relevant and the regression analysis highlighted the association of risk genotype-interactions with increased THBS1 levels in hypertension. Genetic studies of additional thrombospondin pathway-related genes suggest the complex role of THBS1 in the presence of its family members and the related receptor molecules at HA.
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- 2021
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12. Exposure to air pollutants and risk of congenital anomalies: A systematic review and metaanalysis.
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Ravindra K, Chanana N, and Mor S
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- Databases, Factual, Female, Humans, Infant, Newborn, Maternal Exposure adverse effects, Nitrogen Dioxide, Particulate Matter adverse effects, Pregnancy, Air Pollutants adverse effects, Air Pollution adverse effects, Congenital Abnormalities epidemiology, Environmental Pollutants
- Abstract
Background: Congenital malformations are considered as one of the significant causes of preterm as well as neonatal morbidity and mortality. Literature suggests the association of diverse congenital deformities with maternal exposure to air pollutants. However, the evidence is still inconclusive on the manifestation of these during pregnancy. Thus, systematic review was done on the available epidemiological studies studying the effect of air pollutants on congenital malformations. Furthermore, the meta-analysis was conducted for several combinations of air pollutants and congenital defects., Methods: Twenty six epidemiological studies were extracted from the databases and examined for association of risk of congenital defects with air pollutant concentrations. Metaanalysis was done if the risk estimates of the same anomaly and pollutant group were reported in at least three studies., Results: Each study reported a statistically significant increased risk of congenital malformation with some air pollutant, amid the several tested combinations. Our meta-analysis reported that nitrogen dioxide and PM
2.5 were associated with the risk of pulmonary valve stenosis with OR = 1.74 and OR = 1.42 respectively. The risk of developing tetralogy of Fallot (TOF) was observed to be associated with PM2.5 with OR = 1.52. SO2 exposure was related to a high risk of the ventricular septal defect (VSD) with OR = 1.15 and orofacial defects (OR = 1.27)., Conclusion: It is evidenced that ambient air pollutants have some effect on congenital malformations. Standard case definitions, improved methods of exposure, and better control of confounders will improve future research in this area., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2021
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13. Vascular homeostasis at high-altitude: role of genetic variants and transcription factors.
- Author
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Chanana N, Palmo T, Newman JH, and Pasha MAQ
- Abstract
High-altitude pulmonary edema occurs most frequently in non-acclimatized low landers on exposure to altitude ≥2500 m. High-altitude pulmonary edema is a complex condition that involves perturbation of signaling pathways in vasoconstrictors, vasodilators, anti-diuretics, and vascular growth factors. Genetic variations are instrumental in regulating these pathways and evidence is accumulating for a role of epigenetic modification in hypoxic responses. This review focuses on the crosstalk between high-altitude pulmonary edema-associated genetic variants and transcription factors, comparing high-altitude adapted and high-altitude pulmonary edema-afflicted subjects. This approach might ultimately yield biomarker information both to understand and to design therapies for high-altitude adaptation., (© The Author(s) 2020.)
- Published
- 2020
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14. Sex-derived attributes contributing to SARS-CoV-2 mortality.
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Chanana N, Palmo T, Sharma K, Kumar R, Graham BB, and Pasha Q
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- Angiotensin-Converting Enzyme 2, Betacoronavirus drug effects, Betacoronavirus metabolism, COVID-19, Coronavirus Infections epidemiology, Coronavirus Infections genetics, Coronavirus Infections virology, Estradiol metabolism, Estradiol pharmacology, Female, Gene Expression Regulation drug effects, Humans, Male, Mortality, Pandemics, Peptidyl-Dipeptidase A genetics, Peptidyl-Dipeptidase A metabolism, Pneumonia, Viral epidemiology, Pneumonia, Viral genetics, Pneumonia, Viral virology, Renin-Angiotensin System drug effects, SARS-CoV-2, Serine Endopeptidases genetics, Serine Endopeptidases metabolism, Sex Factors, Viral Load drug effects, Viral Load genetics, Betacoronavirus pathogenicity, Coronavirus Infections mortality, Gonadal Steroid Hormones physiology, Pneumonia, Viral mortality, Sex Characteristics
- Abstract
Epidemiological data in COVID-19 mortality indicate that men are more prone to die of SARS-CoV-2 infection than women, but biological causes for this sexual dimorphism are unknown. We discuss the prospective behavioral and biological differences between the sexes that could be attributed to this sex-based differentiation. The female sex hormones and the immune stimulatory genes, including Toll-like receptors, interleukins, and micro-RNAs present on X-chromosome, may impart lesser infectivity and mortality of the SARS-CoV-2 in females over males. The sex hormone estrogen interacts with the renin-angiotensin-aldosterone system, one of the most critical pathways in COVID-19 infectivity, and modulates the vasomotor homeostasis. Testosterone on the contrary enhances the levels of the two most critical molecules, angiotensin-converting enzyme 2 (ACE2) and the transmembrane protease serine-type 2 (TMPRSS2), transcriptionally and posttranslationally, thereby increasing viral load and delaying viral clearance in men as compared with women. We propose that modulating sex hormones, either by increasing estrogen or antiandrogen, may be a therapeutic option to reduce mortality from SARS-CoV-2.
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- 2020
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15. Development, validation and evaluation of a novel self-instructional module in patients with chronic non-specific low back pain.
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Ghai B, Gudala K, Asrar MM, Chanana N, Kanukula R, and Bansal D
- Abstract
Background: Low back pain (LBP) is ranked highest in terms of disability-adjusted life-years lived. Patient education and self-management have shown to play a crucial role in the overall pain management. However, the literature on the same with respect to Indian context is still lacking. The study was aimed to develop, validate and assess the acceptability and effectiveness of self-instructional educational module among Indian chronic LBP (CLBP) patients., Methods: A prospective single-arm open-label study was conducted in a pain clinic of a tertiary care public hospital in North India with 'Backcare booklet-self-instructional module (SIM)' as an intervention in patients with CLBP. SIM was developed with the intent to provide up-to-date evidence-based information in an easy understanding way to patients with CLBP. 132 patients were administered SIM with a single session of verbal explanation. Pain intensity (numeric rating scale [NRS]), disability, fear-avoidance belief Questionnaire (FABQ), quality of life (EQ5D) and knowledge level were assessed at baseline and after 3 months of intervention. Student's paired t -test and Chi-square test were used. Data were analysed using SPSS version 15.0., Results: 120 patients successfully completed the 3 months' follow-up. Significant reductions were observed in pain intensity (76[12] vs 55 [15, P < 0.01); disability (51[14] vs 43 [10], P < 0.01); FABQ (46[12] vs 41 [10], P < 0.01); EQ5D (0.35 [0.27] vs 0.18 [0.26], P < 0.01)., Conclusion: Backcare booklet as an intervention, along with usual pharmacological care is a cost-effective educational medium to promote self-management of CLBP in the clinical outpatient settings., Competing Interests: There are no conflicts of interest., (Copyright: © 2020 Indian Journal of Anaesthesia.)
- Published
- 2020
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16. ORP150-CHIP chaperone antagonism control BACE1-mediated amyloid processing.
- Author
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Chanana N and Pati U
- Subjects
- Amyloid Precursor Protein Secretases genetics, Amyloid beta-Peptides genetics, Aspartic Acid Endopeptidases genetics, Cell Line, Tumor, HEK293 Cells, HSP70 Heat-Shock Proteins genetics, Humans, Peptide Fragments genetics, Ubiquitin-Protein Ligases genetics, Amyloid Precursor Protein Secretases metabolism, Amyloid beta-Peptides metabolism, Aspartic Acid Endopeptidases metabolism, HSP70 Heat-Shock Proteins metabolism, Peptide Fragments metabolism, Proteolysis, Ubiquitin-Protein Ligases metabolism
- Abstract
BACE1, a key protein involved in Alzheimer's progression, initiates Aβ42 generation that induce senile plaques in brain. However, the role of chaperone synergy or antagonism on BACE1-mediated amyloid processing is unknown. We have discovered that BACE1 as well as Aβ42 are antagonistically controlled by ER chaperone ORP150 and cellular chaperone CHIP. We have shown ORP150 as a chaperone interacts with and stabilizes BACE1 at post-translational level. Furthermore, ORP150 enhances BACE1-mediated amyloid processing thus masking CHIP-mediated BACE1 degradation. Conversely, siORP150 reversed the chaperone function of ORP150 resulting in BACE1 degradation. ORP150 and CHIP demonstrate antagonism under normal and stress conditions wherein they inversely regulate each other thus affecting BACE1 level. In conclusion, we have uncovered for the first time a phenomenon of chaperone antagonism on BACE1-mediated Aβ42 generation. Future strategy would require both suppression of ORP150 as well as activation of E3-ligase activity of CHIP that might prevent Aβ42 in Alzheimer's disease., (© 2017 Wiley Periodicals, Inc.)
- Published
- 2018
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17. Alteration of Cardiac Deformation in Acute Rejection in Pediatric Heart Transplant Recipients.
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Chanana N, Van Dorn CS, Everitt MD, Weng HY, Miller DV, and Menon SC
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- Acute Disease, Adolescent, Child, Female, Heart Diseases physiopathology, Humans, Male, Retrospective Studies, Transplants, Graft Rejection physiopathology, Heart physiopathology, Heart Diseases surgery, Heart Transplantation, Heart Ventricles physiopathology
- Abstract
The objective of this study is to assess changes in cardiac deformation during acute cellular- and antibody-mediated rejection in pediatric HT recipients. Pediatric HT recipients aged ≤18 years with at least one episode of biopsy-diagnosed rejection from 2006 to 2013 were included. Left ventricular systolic S (SS) and SR (SSr) data were acquired using 2D speckle tracking on echocardiograms obtained within 12 h of right ventricular endomyocardial biopsy. A mixed effect model was used to compare cardiac deformation during CR (Grade ≥ 1R), AMR (pAMR ≥ 2), and mixed rejection (CR and AMR positive) versus no rejection (Grade 0R and pAMR 0 or 1). A total of 20 subjects (10 males, 50%) with 71 rejection events (CR 35, 49%; AMR 21, 30% and mixed 15, 21%) met inclusion criteria. The median time from HT to first biopsy used for analysis was 5 months (IQR 0.25-192 months). Average LV longitudinal SS and SSr were reduced significantly during rejection (SS: -17.2 ± 3.4% vs. -10.7 ± 4.5%, p < 0.001 and SSr: -1.2 ± 0.2 s
- 1 vs. -0.9 ± 0.3 s- 1 ; p < 0.001) and in all rejection types. Average LV short-axis radial SS was reduced only in CR compared to no rejection (p = 0.04), while average LV circumferential SS and SSr were reduced significantly in AMR compared to CR (SS: 18.9 ± 4.2% vs. 20.8 ± 8.8%, p = 0.03 and SSr: 1.35 ± 0.8 s- 1 vs. 1.54 ± 0.9 s- 1 ; p = 0.03). In pediatric HT recipients, LV longitudinal SS and SSr were reduced in all rejection types, while LV radial SS was reduced only in CR. LV circumferential SS and SSr further differentiated between CR and AMR with a significant reduction seen in AMR as compared to CR. This novel finding suggests mechanistic differences between AMR- and CR-induced myocardial injury which may be useful in non-invasively predicting the type of rejection in pediatric HT recipients.- Published
- 2017
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18. Outcome following augmentation of superior cavopulmonary blood flow with an arteriovenous fistula.
- Author
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Chanana N, Day RW, McGough EC, and Burch PT
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- Adolescent, Axillary Artery surgery, Axillary Vein surgery, Child, Child, Preschool, Cyanosis blood, Cyanosis surgery, Female, Heart Bypass, Right methods, Heart Defects, Congenital blood, Heart Transplantation methods, Humans, Male, Oximetry, Oxygen blood, Palliative Care methods, Pulmonary Circulation physiology, Reoperation methods, Treatment Outcome, Vascular Patency physiology, Arteriovenous Shunt, Surgical methods, Heart Defects, Congenital surgery, Heart Ventricles abnormalities
- Abstract
Background: Axillary or brachial arteriovenous fistulae are occasionally created to improve systemic oxygen saturation in patients with functionally univentricular circulation after superior cavopulmonary anastomosis. Different techniques of fistula construction may account for the conflicting results. We sought to determine the impact of axillary arteriovenous fistula on systemic oxygen saturation and survival before subsequent palliation or heart transplantation., Methods: Medical records of patients who underwent a side-to-side anastomosis between an adjacent axillary artery and vein for cyanosis after superior cavopulmonary anastomosis between 1991 and 2010 were reviewed., Results: The median age (n = 23) at the time of fistula creation was 54 months (4-278 months). There was no operative mortality. The median duration of fistula patency was 48 months (1-174 months). Oxygen saturation improved from 71% ± 10% preoperatively to 84% ± 4% early (P < .05) and 81% ± 4% long term after the arteriovenous fistula (P < .05). Twelve patients underwent additional surgery (total cavopulmonary anastomosis 6, partial biventricular repair 2, and heart transplantation 4) after an interval of 10 to 141 months. Six patients are alive with a patent fistula without subsequent interventions after an interval of 48 to 174 months. Two patients with spontaneous closure or device closure of the fistula are alive after an interval of 76 to 80 months without subsequent interventions. Three deaths occurred with a patent fistula without subsequent interventions after an interval of 1 to 84 months., Conclusions: Systemic oxygen saturation improved with creation of an axillary arteriovenous fistula after superior cavopulmonary anastomosis. The fistula extended the duration of this stage of palliation without precluding the option for additional palliation or heart transplantation., (© The Author(s) 2015.)
- Published
- 2015
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19. Classical limit of quantum Brownian probability.
- Author
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Chanana N, Menon VJ, and Singh Y
- Published
- 1996
- Full Text
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