71 results on '"N. Chacko"'
Search Results
2. Dynamical Facilitation Governs the Equilibration Dynamics of Glasses
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Rahul N. Chacko, François P. Landes, Giulio Biroli, Olivier Dauchot, Andrea J. Liu, and David R. Reichman
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Physics ,QC1-999 - Abstract
Convincing evidence of domain growth in the heating of ultrastable glasses suggests that the equilibration dynamics of supercooled liquids could be driven by a nucleation and growth mechanism. We investigate this possibility by simulating the equilibration dynamics of a model glass during both heating and cooling between poorly and well-annealed states. Though we do observe the growth of domains during heating, we find that domains are absent during cooling. This absence is inconsistent with classical nucleation theory. By comparing the equilibration dynamics of our glass with that of two models with kinetic constraints, we demonstrate that dynamical facilitation generically leads to heating driven by domain growth and cooling without domains. Our results provide strong evidence that dynamical facilitation, not nucleation and interfacial-tension-driven domain growth, is the driving mechanism for the equilibration dynamics of glass formers.
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- 2024
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3. Is shock wave lithotripsy safe in bleeding diathesis?
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Samiran Adhikary, A Devasia, L Gnanaraj, K N Chacko, N Kekre, and G Gopalakrishnan
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Bleeding diathesis ,lithotripsy ,urolithiasis ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
OBJECTIVE: To assess the safety of shock wave lithotripsy (SWL) in treatment of urinary calculi, in patients with bleeding diathesis. MATERIALS AND METHODS: From 1996 to 2004, seven patients with bleeding diathesis were treated by SWL for urolithiasis. Change of oral anticoagulants to heparin (low molecular heparin) and substitution of deficient coagulation factors was done on the day of treatment. RESULTS: Two out of seven patients had mild hematuria, which settled within 48 hours. None of them required transfusion. Six out of seven were stone-free at one month. None of them required any secondary procedure. CONCLUSION: SWL is a safe method for the treatment of urolithiasis in patients with bleeding diathesis, provided deficient coagulation factors are corrected.
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- 2006
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4. Elastoplasticity Mediates Dynamical Heterogeneity Below the Mode Coupling Temperature
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François P. Landes, Rahul N. Chacko, Olivier Dauchot, Giulio Biroli, Andrea J. Liu, David R. Reichman, University of Pennsylvania, James Franck Institute, University of Chicago, TAckling the Underspecified (TAU), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Interdisciplinaire des Sciences du Numérique (LISN), Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL), Gulliver (UMR 7083), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Columbia University [New York], University of Pennsylvania [Philadelphia], Laboratoire Interdisciplinaire des Sciences du Numérique (LISN), CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and École normale supérieure - Paris (ENS Paris)
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Physics ,Chemical Physics (physics.chem-ph) ,Statistical Mechanics (cond-mat.stat-mech) ,Component (thermodynamics) ,General Physics and Astronomy ,FOS: Physical sciences ,Condensed Matter - Soft Condensed Matter ,01 natural sciences ,Condensed Matter::Disordered Systems and Neural Networks ,010305 fluids & plasmas ,Condensed Matter::Soft Condensed Matter ,Coupling (physics) ,Chemical physics ,Physics - Chemical Physics ,0103 physical sciences ,Soft Condensed Matter (cond-mat.soft) ,Dynamical heterogeneity ,[PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn] ,010306 general physics ,Supercooling ,Glass transition ,[PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft] ,Condensed Matter - Statistical Mechanics - Abstract
As liquids approach the glass transition temperature, dynamical heterogeneity emerges as a crucial universal feature of their behavior. Dynamic facilitation, where local motion triggers further motion nearby, plays a major role in this phenomenon. Here we show that long-range, elastically-mediated facilitation appears below the mode-coupling temperature, adding to the short-range component present at all temperatures. Our results suggest deep connections between the supercooled liquid and glass states, and pave the way for a deeper understanding of dynamical heterogeneity in glassy systems., 6 pages, 4 figures. SM included as ancillary
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- 2021
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5. Mental Stress in Patients Undergoing Radiation Therapy: The Impact of Mindfulness and Social Support
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Bhupesh Parashar, K. Sharma, N. Chacko, R. Mehta, A. Shah, Z.H. Rana, T. Minutoli, A. Matarangas, J. Eckstein, J. Mancuso, and Louis Potters
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Cancer Research ,Radiation ,Psychotherapist ,Mindfulness ,business.industry ,medicine.medical_treatment ,Radiation therapy ,Social support ,Oncology ,Mental stress ,medicine ,Radiology, Nuclear Medicine and imaging ,In patient ,business - Published
- 2020
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6. Slow coarsening in jammed athermal soft particle suspensions
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Peter Sollich, Rahul N. Chacko, and Suzanne M. Fielding
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Materials science ,Elastic energy ,FOS: Physical sciences ,General Physics and Astronomy ,Mechanics ,Condensed Matter - Soft Condensed Matter ,01 natural sciences ,Power law ,Amorphous solid ,Root mean square ,0103 physical sciences ,Soft Condensed Matter (cond-mat.soft) ,Initial value problem ,Particle ,Vector field ,Deformation (engineering) ,010306 general physics - Abstract
We simulate a densely jammed, athermal assembly of repulsive soft particles immersed in a solvent. Starting from an initial condition corresponding to a quench from a high temperature, we find non-trivial slow dynamics driven by a gradual release of stored elastic energy, with the root mean squared particle speed decaying as a power law in time with a fractional exponent. This decay is accompanied by the presence within the assembly of spatially localised and temporally intermittent `hot-spots' of non-affine deformation, connected by long-ranged swirls in the velocity field, reminiscent of the local plastic events and long-ranged elastic propagation that have been intensively studied in sheared amorphous materials. The pattern of hot-spots progressively coarsens, with the hot-spot size and separation slowly growing over time, and the associated velocity correlation length increasing as a sublinear power law. Each individual spot however exists only transiently, within an overall picture of strongly intermittent dynamics., 5 pages, 5 figures. Ancillary files SM.pdf and movie.avi
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- 2019
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7. Shear reversal in dense suspensions: The challenge to fabric evolution models from simulation data
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Suzanne M. Fielding, Rahul N. Chacko, Michael E. Cates, Romain Mari, Cates, Michael [0000-0002-5922-7731], Apollo - University of Cambridge Repository, Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS), Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge [UK] (CAM), and Mari, Romain
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Stokesian dynamics ,Second moment of area ,FOS: Physical sciences ,Condensed Matter - Soft Condensed Matter ,01 natural sciences ,010305 fluids & plasmas ,Stress (mechanics) ,0103 physical sciences ,Newtonian fluid ,suspensions ,010306 general physics ,Anisotropy ,Condensed Matter - Statistical Mechanics ,ComputingMilieux_MISCELLANEOUS ,Physics ,Statistical Mechanics (cond-mat.stat-mech) ,Mechanical Engineering ,Mathematical analysis ,Fluid Dynamics (physics.flu-dyn) ,Spherical harmonics ,Hard spheres ,Physics - Fluid Dynamics ,Condensed Matter Physics ,[PHYS.COND.CM-SCM] Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft] ,Nonlinear system ,Mechanics of Materials ,Soft Condensed Matter (cond-mat.soft) ,rheology ,[PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft] - Abstract
Despite the industrial importance of dense suspensions of hard particles, few constitutive models for them have been proposed or tested. Most of these are effectively "fabric evolution models" (FEMs) based on a stress rule connecting the bulk stress to a rank-2 microstructural fabric tensor Q and a closed time-evolution equation for Q. In dense suspensions most of the stress comes from short-ranged pairwise steric or lubrication interactions at near-contacts, so a natural choice for Q is the deviatoric 2nd moment of the distribution P(p) of the near-contact orientations p. Here we test directly whether a closed time-evolution equation for such a Q can exist for inertialess non-Brownian hard spheres in a Newtonian solvent. We perform extensive numerical simulations for the evolution of P(p) under shear reversal, providing a stringent test for FEMs. We consider a generic class of these as defined by Hand (1962) constrained only by frame indifference. Motivated by the small microstructural anisotropy in the dense regime, we start with linear models and successively consider increasingly nonlinear ones. Based on these results we suggest that no closed FEM properly describes the dynamics of Q under reversal. We attribute this to the fact that Q gives a poor description of the microstructure during large parts of the microstructural evolution following shear reversal. Specifically, the truncation of P(p) at 2nd spherical harmonic level describes two-lobed distributions of near-contact orientations, whereas on reversal we observe distributions that are markedly four-lobed; moreover dP/dt (p) has oblique axes, not collinear with those of Q in the shear plane. This structure likely precludes any adequate closure at second-rank level. Instead, our numerical data suggest that closures involving the coupled evolution of both a fabric tensor and a fourth-rank tensor might be reasonably accurate., 30 pages, 13 Figures
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- 2018
8. Dynamic vorticity banding in discontinuously shear thickening suspensions
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Romain Mari, Suzanne M. Fielding, Rahul N. Chacko, Michael E. Cates, Cates, Michael [0000-0002-5922-7731], Apollo - University of Cambridge Repository, Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS), and Mari, Romain
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Physics ,Dilatant ,Continuum (measurement) ,Computation ,Fluid Dynamics (physics.flu-dyn) ,FOS: Physical sciences ,General Physics and Astronomy ,0914 Resources Engineering and Extractive Metallurgy ,Mechanics ,Physics - Fluid Dynamics ,Vorticity ,Condensed Matter - Soft Condensed Matter ,01 natural sciences ,[PHYS.COND.CM-SCM] Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft] ,010305 fluids & plasmas ,Physics::Fluid Dynamics ,Nonlinear system ,Linear stability analysis ,Homogeneous ,0103 physical sciences ,Soft Condensed Matter (cond-mat.soft) ,010306 general physics ,[PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft] ,ComputingMilieux_MISCELLANEOUS - Abstract
It has recently been argued that steady-state vorticity bands cannot arise in shear thickening suspensions, because the normal stress imbalance across the interface between the bands will set up particle migrations. In this Letter, we develop a simple continuum model that couples shear thickening to particle migration. We show by linear stability analysis that homogeneous flow is unstable towards vorticity banding, as expected, in the regime of negative constitutive slope. In full nonlinear computations, we show however that the resulting vorticity bands are unsteady, with spatiotemporal patterns governed by stress-concentration coupling. We furthermore show that these dynamical bands also arise in direct particle simulations, in good agreement with the continuum model., 5 pages, 3 figures. Published in PRL. Copyright transferred to APS
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- 2018
9. Clinical outcomes and nonendoscopic interventions after minor papilla endotherapy in patients with symptomatic pancreas divisum
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Yang K. Chen, Raj J. Shah, and Lyssa N. Chacko
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Adult ,Male ,medicine.medical_specialty ,Abdominal pain ,Pancreatic disease ,medicine.medical_treatment ,Gastroenterology ,Catheterization ,Sphincterotomy, Endoscopic ,Interquartile range ,Surveys and Questionnaires ,Internal medicine ,medicine ,Humans ,Pain Management ,Radiology, Nuclear Medicine and imaging ,Endoscopy, Digestive System ,Pancreas ,Pancreas divisum ,business.industry ,Pancreatic Ducts ,Chronic pain ,Balloon Occlusion ,Middle Aged ,medicine.disease ,Abdominal Pain ,Surgery ,Treatment Outcome ,Pancreatitis ,Acute Disease ,Acute pancreatitis ,Female ,Stents ,Puestow procedure ,medicine.symptom ,business ,Follow-Up Studies - Abstract
Background Long-term outcomes of minor papilla endotherapy (MPE) in pancreas divisum are limited. Objective To determine the efficacy of MPE in symptomatic pancreas divisum subgroups. Design This was a retrospective study of patients from an endoscopy database. The data collection instrument included preprocedure and postprocedure pain score, narcotic use, acute pancreatitis episodes, emergency department visits, and hospitalizations. A follow-up was obtained by chart review and telephone contact with a questionnaire. Setting A tertiary-referral center. Main Outcome Measurements (1) Clinical improvement defined as a ≥50% reduction in the evaluated data points and (2) non-MPE interventions for pain. Results Between January 2000 and April 2006, 57 patients were identified. Indications were recurrent acute pancreatitis (RAP) (n = 27 [47%]), abdominal pain and chronic pancreatitis (CP) (n = 20 [35%]), abdominal pain alone (n = 8 [14%]), other (n = 2 [4%]). Successful MPE occurred in 49 of 57 patients (86%). Initial MPE entailed minor papilla sphincterotomy (n = 46), stenting without sphincterotomy (n = 2), and tamponade of bleeding (n = 1). Follow-up was obtained in 56 of 57 patients (98%) for a median of 20 months (interquartile range 12-39 months); 28 of 48 patients (58%) with successful MPE had clinical improvement: 16 of 21 (76%) with RAP, 8 of 19 (42%) with CP, and 2 of 6 (33%) with pain alone (RAP vs non-RAP; P = .019). Two patients had resolution of a dorsal-duct leak and bleeding, respectively. Twelve of 57 patients (21%) underwent 16 additional interventions for incomplete response: celiac plexus block (4), intrathecal narcotic pump (2), sphincteroplasty (7), bilateral thoracic splanchnicectomy (2), and Puestow procedure (1); 7 of 12 patients (58%) clinically improved. Limitation This was a retrospective study. Conclusions (1) MPE is most effective in patients with pancreas divisum and with RAP with or without pancreatic ductal changes, (2) although patients with chronic pain and pancreas divisum respond poorly to MPE, the majority will have clinical improvement after additional nonendoscopic interventions for pain management.
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- 2008
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10. APOPHYSOMYCES ELEGANS - RENAL MUCORMYCOSIS IN A HEALTHY HOST: A CASE REPORT FROM SOUTH INDIA
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A J, Thomas, S, Shah, M S, Mathews, and N, Chacko
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Adult ,Male ,Microbiology (medical) ,Antifungal Agents ,Amphotericin B ,Mucorales ,Humans ,India ,Mucormycosis ,Kidney Diseases ,Nephrectomy - Abstract
Zygomycosis is an opportunistic fungal infection that seldom occurs in individuals with a competent immune system. Isolated involvement of any organ is rare and only a few cases of renal zygomycosis have been reported. We present an unusual case of renal zygomycosis caused by Apophysomyces elegans in a patient with no known predisposing factor. He presented with flakes in the urine and was found to have a poorly functioning right kidney. Ureterorenoscopy was performed, fungal elements removed and pathological confirmation obtained. The patient subsequently underwent nephrectomy after treatment with amphotericin B. He made an uneventful recovery.
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- 2008
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11. Serum GGT activity and hsCRP level in patients with type 2 diabetes mellitus with good and poor glycemic control: An evidence linking oxidative stress, inflammation and glycemic control
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Mukesh G. Gohel and Anusha N Chacko
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medicine.medical_specialty ,Cross-sectional study ,Endocrinology, Diabetes and Metabolism ,Inflammation ,Glycemic Control ,medicine.disease_cause ,Pathogenesis ,Diabetes Mellitus Patient ,Good Glycemic Control ,Internal medicine ,Diabetes mellitus ,Internal Medicine ,medicine ,Glycemic ,hsCRP Level ,biology ,business.industry ,C-reactive protein ,Type 2 Diabetes Mellitus ,medicine.disease ,Endocrinology ,biology.protein ,Poor Glycemic Control ,medicine.symptom ,business ,Oxidative stress ,Research Article - Abstract
Background Diabetes is undoubtedly one of the most challenging health problems in 21st century. Understanding the pathogenesis and preventing long term complications have been major goals of research in diabetes mellitus (DM). Research in the past few years has linked oxidative stress and inflammation to beta cell dysfunction. Aim of this study is to evaluate serum gamma-glutamyl transferase (GGT) activity (marker of oxidative stress) and high sensitivity C reactive protein (hsCRP) level (an inflammatory marker) in type 2 DM subjects with good and poor glycemic control. Further, we investigated correlation between serum GGT and hsCRP level with glycemic control (FBS, PP2BS, HbA1c) in subjects. Methods A cross sectional study consists of 150 patients out of them 50 patients having type 2 DM with good control (Group II), 50 patients with type 2 DM with poor control (Group III) and 50 normal healthy control (Group I) were selected. Serum GGT, serum hsCRP, FBS, PP2BS, HbA1c, and other biochemical investigations include serum liver enzymes and lipids were measured. Results Mean serum GGT and hsCRP concentration were statistically significantly higher in group III patients compared to group I and group II subjects as well as increased in group II compared to group I (p < 0.001). Further significant positive correlation was observed between GGT and hsCRP concentration as well as both with HbA1c, FBS, and PP2BS. Conclusions Oxidative stress and inflammation appears to be a key component and also associated with poor glycemic control and further pathogenesis of diabetes and its complications. All our finding suggesting a link between oxidative stress, inflammation and glycemic control in patient with type 2 diabetes mellitus.
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- 2013
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12. Pathological investigation of an outbreak of fowl typhoid in a duck farm in Kerala
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Mammen J. Abraham, K. Krithiga, N. Chacko, A. J. George, N. Natarajan, Nithya Chacko, and N. D. Nair
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Serotype ,Veterinary medicine ,medicine.medical_specialty ,business.industry ,Veterinary pathology ,Outbreak ,medicine.disease ,Sudden death ,Pericarditis ,Perihepatitis ,medicine ,Histopathology ,Vasculitis ,business - Abstract
A disease outbreak in a duck farm of 5,000 birds from Thrissur, Kerala was investigated. Three ducks of 8 month, with the history of droopiness and sudden death were presented to the Department of Veterinary Pathology, College of Veterinary and Animal Sciences, Mannuthy for necropsy examination. On necropsy, fibrinous pericarditis, perihepatitis, airsacculitis and hydropericardium could be observed. Blood smear examination revealed clumps of coccobacilli interspersed among the blood cells. Affected tissue samples were collected for histopathology and bacteriological examination. Histopathology revealed fibrinous pericarditis with infiltration of heterophils, vasculitis, vacuolation of hepatic parenchyma and pulmonary congestion with interstitial haemorrhages. Bacteriological studies showed gram negative small rods, which when serotyped were confirmed as Salmonella gallinarum serotype 9, 12, thus confirming fowl typhoid. This report points out the importance of better management practices, proper disease investigation and surveillance for achieving efficient growth rate and profitability in poultry industry.
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- 2017
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13. Tubercular ureteric strictures
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Maneesh, Sinha, K N, Chacko, N S, Kekre, and Ganesh, Gopalakrishnan
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Adult ,Male ,Adolescent ,Tuberculosis, Urogenital ,Middle Aged ,Catheterization ,Treatment Outcome ,Humans ,Urologic Surgical Procedures ,Female ,Child ,Follow-Up Studies ,Retrospective Studies ,Ureteral Obstruction - Abstract
To review the presentation of tubercular ureteric strictures and assesses the role of balloon dilatation and open surgical repair in their management.This was a retrospective review of tubercular ureteric strictures managed between January 1993 and December 2002. The records were analyzed to assess clinical presentation and compare the results of balloon dilatation with open surgical repair. Success was defined as adequate drainage on imaging, no worsening of renal function, no recurrence of symptoms and no requirement of intervention on further follow up. The long term success rates were compared using the t-test for proportion.Of 73 strictures, 88% had lower urinary tract symptoms. Genital abnormalities suggestive of tuberculosis was observed in 40% male patients. Urine examination yielded aseptic pyuria in 85%, positive AFB smears in 36% and positive AFB cultures in 32%. A small capacity bladder and non-functioning renal units were the only consistent findings on intravenous urogram. Nephrectomy was performed in 37% cases due to non salvageable kidneys at presentation. The success rate of stenting fell from 93% on immediate follow up to 59% on a follow-up of 12 months. At 90% success rates on a follow-up of 7 months open surgical repair was superior (p 0.03). Long term success following balloon dilatation in renal units with good function was 78% compared to 25% for poorly functioning units. (p= 0.01)Open surgical repair is superior to balloon dilatation in the management of tubercular ureteric strictures. Renal function may predict the success of balloon dilatation.
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- 2005
14. PET imaging in cardiology
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George N, Chacko
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Ventricular Dysfunction, Left ,Fluorodeoxyglucose F18 ,Positron-Emission Tomography ,Practice Guidelines as Topic ,Cardiology ,Humans ,Equipment Design ,Practice Patterns, Physicians' ,Radiopharmaceuticals ,United States - Abstract
The incidence of congestive heart failure (CHF) has progressively increased over the last 25 years with coronary artery disease being the aetiology in 66% of patients with CHF. Assessment of myocardial perfusion and glucose uptake using PET imaging with 18F-FDG for metabolism and 13-N-ammonia or 82-rubidium for coronary flow has proven to be the gold standard for predicting the recovery of regional and global left ventricular (LV) function following revascularization. Patients with viable ischemic myocardium identified by a flow/metabolism mismatch, represent an especially high risk subgroup for hard coronary events within one year, in the absence of myocardial revascularization. The state of the art assessment of myocardial viability in the new millennium is an optimally glucose loaded PET myocardial perfusion/metabolic study. For patients with critically depressed LV function with LVEF20% at rest assessment of contractile reserve, in addition to 18F-FDG-PET viability imaging, may help predict a favourable surgical outcome.
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- 2005
15. Xanthoma of the urinary bladder – A rare entity
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M. Vimal, Mt T. Manipadam, D. Masih, and Kn N. Chacko
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medicine.medical_specialty ,Urinary bladder ,medicine.diagnostic_test ,business.industry ,Urology ,Rare entity ,Cystoscopy ,Xanthoma ,lcsh:Diseases of the genitourinary system. Urology ,lcsh:RC870-923 ,medicine.disease ,urologic and male genital diseases ,Uropathology ,female genital diseases and pregnancy complications ,xanthoma ,medicine.anatomical_structure ,medicine ,cystoscopy ,business - Abstract
Xanthomas of the urinary bladder are rare. They may be associated with metabolic disorders. We hereby report a case of bladder xanthoma.
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- 2012
16. Correlation of serum prostate specific antigen levels and bone scintigraphy in carcinoma prostate
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R K Roul, F S Geethanjali, R Oommen, N Chacko, A S Kanagasabapathy, G Gopalakrishnan, and S John
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Male ,medicine.medical_specialty ,Pathology ,Urology ,Bone Neoplasms ,Adenocarcinoma ,urologic and male genital diseases ,Scintigraphy ,Prostate cancer ,Predictive Value of Tests ,Prostate ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Radionuclide Imaging ,medicine.diagnostic_test ,business.industry ,Prostatic Neoplasms ,General Medicine ,Middle Aged ,Prostate-Specific Antigen ,medicine.disease ,Prostate-specific antigen ,medicine.anatomical_structure ,Bone scintigraphy ,Predictive value of tests ,Hormonal therapy ,business - Abstract
Serum prostate specific antigen (PSA) has been suggested as an accurate means of monitoring prostate cancer. An analysis of PSA levels and bone scan findings was carried out in a heterogeneous group of patients with a view to determine whether PSA can accurately predict bone metastases in carcinoma prostate. Of the 48 patients studied, all 10 untreated cases had elevated PSA levels, eight having bone metastases. In 29 cases on follow-up after treatment of the primary, 10 out of 11 cases with normal PSA had a negative bone scan. In the nine who received hormonal therapy, the PSA levels were generally lower than others in the study group. Two out of four with normal PSA had bone metastases. In 26 cases with positive bone scans, 23 had elevated PSA levels (mean 109.9 ng ml-1). Among 22 patients who had normal bone scans, all 10 with high PSA were found to have soft tissue disease which could explain the elevated PSA. In those with normal PSA, 12 out of 15 patients had negative scans. PSA has fairly high sensitivity (86.5%) and negative predictive value (80%). But it suffers from low specificity (54.5%) and low positive predictive value (69.7%) for bone metastases. In an untreated patient with elevated PSA, a bone scan may be required to exclude bone metastases, whereas during follow-up after treatment, a normal PSA level may obviate a "routine" bone scan.
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- 1994
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17. Aspects of Hypertension in Renal Allograft Recipients A Study of 1000 Live Renal Transplants
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C. K. Jacob, J. C. M. Shastry, N. Chacko, N. I. Mammen, A. P. Pandey, and G. Ganesh
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Graft Rejection ,medicine.medical_specialty ,Hypertension, Renal ,Urology ,Disease ,Renal Artery Obstruction ,Postoperative Complications ,Internal medicine ,Epidemiology ,Humans ,Medicine ,Antihypertensive Agents ,Retrospective Studies ,Kidney ,business.industry ,Retrospective cohort study ,Kidney Transplantation ,Surgery ,Transplantation ,surgical procedures, operative ,medicine.anatomical_structure ,Renal allograft ,Etiology ,business ,Complication ,Algorithms - Abstract
Summary— A retrospective study of 1000 live renal transplants was performed in order to assess the factors associated with hypertension in renal transplant recipients. The prevalence of hypertension prior to transplantation was 48%. The need for antihypertensive drugs decreased in 43%, increased in 31% and remained the same in 26%. The presence of hypertension before transplantation, rejection episodes, transplant renal artery stenosis and native kidney disease were the main factors associated with post-transplant hypertension. An algorithm for the management of post-transplant hypertension is suggested.
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- 1993
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18. A prospective randomized trial comparing transurethral resection of the prostate and laser therapy in men with chronic urinary retention: The CLasP study
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S, Gujral, P, Abrams, J L, Donovan, D E, Neal, S T, Brookes, K N, Chacko, M J, Wright, A G, Timoney, and T J, Peters
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Male ,Prostatic Hyperplasia ,Transurethral Resection of Prostate ,Humans ,Laser Therapy ,Prospective Studies ,Middle Aged ,Urinary Retention ,Severity of Illness Index - Abstract
We assessed the effectiveness of laser therapy versus transurethral prostatic resection in men with symptomatic chronic urinary retention secondary to benign prostatic enlargement.This trial was multicenter, pragmatic and randomized. Analysis was done by intent to treat. Laser therapy involved neodymium:YAG noncontact visual prostate ablation, while transurethral prostatic resection was performed by standard electroresection. Patients were included in our study if they reported moderate to severe lower urinary tract symptoms with an International Prostate Symptom Score (I-PSS) of 8 or more, benign prostatic enlargement and a persistent post-void residual urine volume of more than 300 ml. Followup was 7.5 months. Primary outcome measures included the I-PSS, I-PSS quality of life score, maximum urinary flow and post-void residual urine volume. Secondary outcome measures included treatment failure, complications, hospital stay and catheterization time.A total of 82 patients agreed to be randomized to receive laser therapy (38) or transurethral prostatic resection (44). There were significant improvements in all primary outcomes in each group from randomization to followup. Transurethral prostatic resection was significantly better than laser therapy for I-PSS and maximum urinary flow values (p = 0.035 and 0.029, respectively) but there were no differences in post-void residual urine volume and I-PSS quality of life score between the groups. We noted significantly more treatment failures with laser therapy than resection (8 versus 0, p = 0.0014), although only 3 patients required resection after laser therapy because of persistent symptoms. In addition, hospital stay after resection was 2-fold that after laser therapy (ratio of geometric means 2.01, 95% confidence interval 1.54 to 2.61, p0.0001). However, time to catheter removal was 9 times longer in the laser therapy group (p0. 0001). Complication rates were significantly higher for transurethral prostatic resection (chi-square 5.05, 1 df, p = 0.025).Transurethral prostatic resection is more effective than laser ablation in men with chronic urinary retention in terms of symptom score, maximum urinary flow and failure. However, men who underwent resection had significantly more treatment complications and were hospitalized longer than those who received laser therapy. This finding implies that laser ablation therapy may have a role in patients at higher risk who are willing to accept a lower level of effectiveness in exchange for decreased complication rates and hospital stay.
- Published
- 2000
19. Transplant kidney protection during aortic aneurysm surgery
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K N, Chacko, S, Ninan, C K, Jacob, and R, Korula
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Male ,Intraoperative Care ,Ischemia ,Humans ,Middle Aged ,Kidney ,Kidney Transplantation ,Aortic Aneurysm, Abdominal - Abstract
Renal allografts are sensitive to ischemic insult. During aortic cross clamping prevention of ischemic damage to a kidney below an aneurysm is vital. Many maneuvers have been reported. We describe a simple technique of protecting the transplant kidney from ischemic damage during aortic surgery.During vascular cross clamping a sterile ice slush was placed around the kidney for surface cooling, obviating the need for some of the complicated procedures previously reported.After removal of the ice slush and clamps, urine production resumed and creatinine levels remained unchanged.External cooling with ice slush provides adequate renal protection during aortic cross clamping and requires no special expertise or equipment.
- Published
- 1999
20. Percutaneous removal of a 'bullet' from the liver
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K N, Chacko, S R, Jesudason, and S, Ninan
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Male ,Adolescent ,Liver ,Humans ,Endoscopy ,Wounds, Gunshot ,Foreign Bodies - Published
- 1996
21. Transcervical endometrial resection when hysterectomy is dangerous
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N, Chacko, L, Seshadri, and S, Ninan
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Adult ,Endometrium ,Risk Factors ,Endometrial Hyperplasia ,Hysteroscopes ,Humans ,Female ,Uterine Hemorrhage ,Emergencies ,Hysterectomy ,Dilatation and Curettage - Abstract
Severe blood loss from dysfunctional uterine bleeding may be refractory to medical therapy and hysterectomy the only option. In two young women with severe bleeding where medical measures were ineffective and hysterectomy was a hazardous option, we performed a transcervical endometrial resection. In both of them the bleeding stopped immediately and no further treatment was required for dysfunctional uterine bleeding. They have had amenorrhea now for over six months. Transcervical endometrial resection is an option when hysterectomy is hazardous and the bleeding is refractory to medical treatment.
- Published
- 1995
22. Apophysomyces elegans - renal mucormycosis in a healthy host: A case report from south India
- Author
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AJ Thomas, S Shah, N Chacko, and Mathews
- Subjects
Microbiology (medical) ,Kidney ,Pathology ,medicine.medical_specialty ,Unusual case ,business.industry ,medicine.medical_treatment ,Mucormycosis ,medicine.disease ,Nephrectomy ,Apophysomyces elegans ,medicine.anatomical_structure ,medicine ,Zygomycosis ,business ,Pathological ,After treatment - Abstract
Zygomycosis is an opportunistic fungal infection that seldom occurs in individuals with a competent immune system. Isolated involvement of any organ is rare and only a few cases of renal zygomycosis have been reported. We present an unusual case of renal zygomycosis caused by Apophysomyces elegans in a patient with no known predisposing factor. He presented with flakes in the urine and was found to have a poorly functioning right kidney. Ureterorenoscopy was performed, fungal elements removed and pathological confirmation obtained. The patient subsequently underwent nephrectomy after treatment with amphotericin B. He made an uneventful recovery.
- Published
- 2008
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23. Trichouria due to benign retrovesical teratoma
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K. N. Chacko, A. P. Pandey, and A. Basu
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Male ,medicine.medical_specialty ,business.industry ,Urology ,General surgery ,medicine.disease ,Surgery ,Urinary Bladder Neoplasms ,medicine ,Humans ,Teratoma ,business ,Child ,Dermoid Cyst ,Hair - Published
- 1990
24. Barrettʼs Esophagus Surveillance in a VA Population: A 2-Year Retrospective Analysis
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Amit Goyal and Lyssa N. Chacko
- Subjects
education.field_of_study ,medicine.medical_specialty ,medicine.anatomical_structure ,Hepatology ,business.industry ,General surgery ,Population ,Gastroenterology ,Retrospective analysis ,Medicine ,Esophagus ,business ,education - Published
- 2007
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25. Tuberculosis of urinary bladder presenting as pseudoureterocele
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A. Rao, K Yvette, and N Chacko
- Subjects
Neck of urinary bladder ,medicine.medical_specialty ,Urinary bladder ,medicine.anatomical_structure ,Tuberculosis ,business.industry ,Urology ,Medicine ,General Medicine ,business ,medicine.disease - Published
- 2005
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26. COMPREHENSIVE ANALYSIS OF LSFs
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J. R. Prince, D. J. Wood, A. M. Daus, M. F. D'souza, J. R. Sonnad, and G. N. Chacko
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business.industry ,Management science ,Medicine ,Radiology, Nuclear Medicine and imaging ,General Medicine ,business - Published
- 1996
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27. A cost comparison of open versus percutaneous approaches to management of large staghorn calculi
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Maneesh Sinha, K R John, K N Chacko, and Ganesh Gopalakrishnan
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Open surgery ,percutaneous nephrolithotripsy ,staghorn calculi ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Aim: This paper compares the cost of open versus percutaneous approaches to the management of large staghorn calculi in a tertiary care hospital in India. Materials and Methods: Patients who underwent surgery for staghorn calculi larger than 6 cm between January 1998 and December 2003 were included. Those who had confounding factors in terms of cost such as additional surgical or medical procedures and complications unrelated to the surgery were excluded. The process of costing was done by following the clinical pathway. Results: There were 13 patients who had open stone surgery and 19 patients who underwent percutaneous nephrolithotripsy (PCNL). The major differences in cost were seen in the higher cost of instruments and consumables in the PCNL group. The cost of management of complications widened this gap. Two patients in the PCNL group and none in the residual group required redo surgery. The residual stones in the open and PCNL groups required a mean of 2525 and 3623 shocks per patient respectively. Complete clearance after redo surgery and Shockwave lithotripsy (SWL) was seen in 92% and 58% in the open and PCNL arms respectively. The overall cost per patient was $625 per PCNL and $499 per open surgery. The final mean residual stone size in the PCNL group was 4.84 mm whereas it was 0.38 mm in the open group. The effective cost of achieving complete clearance in one patient was $1078 in the PCNL group and $543 in the open group. Conclusion: Open stone surgery is less costly than PCNL in large staghorn calculi.
- Published
- 2008
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28. Sildenafil induced priapism
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Samiran Adhikary, M Sinha, and K N Chacko
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Sildenafil ,priapism ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
An unmarried 35 years old male, who took 25mg sildenafil daily for 8 days followed by 12.5 mg daily for 4 days, with consultation with a local chemist for nocturnal emission developed priapism. He presented to an urologist after 72 hours where a corporal wash and distal shunt was tried but it did not give any relief to the patient. He had no other identified contributing factors for priapism. A proximal caverno-spongiosal shunting (Quackels cavernoso-spongiosal shunts) was done which subsequently relieved his symptoms. To our knowledge this is the first reported case of priapism resulting from supposedly safe doses of sildenafil in a healthy individual. Distal shunts are associated with high failure rates which may warrant a more proximal shunt. Even when seen after a considerable time a shunt may be useful. After the delayed surgery, relief of pain without complete detumesence suggests a role for watch-full waiting. This case also highlights the existence of unfortunate myths surrounding the omnipotence of sildenafil in all sorts of sex related problems. It points toward an urgent need for steps to prevent unauthorized prescription and misuse of this drug..
- Published
- 2006
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29. Non-invasive early-stage cancer detection: current methods and future perspectives.
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Chacko N and Ankri R
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- Humans, Spectrum Analysis, Raman methods, Optical Imaging methods, Saliva chemistry, Ultrasonography methods, Breath Tests methods, Diagnostic Imaging methods, Early Detection of Cancer methods, Neoplasms diagnosis, Neoplasms diagnostic imaging, Biomarkers, Tumor
- Abstract
This review paper explores the realm of non-invasive methods for early cancer detection. Early identification is crucial for effective therapeutic intervention, and non-invasive techniques have emerged as promising tools to enhance diagnostic accuracy and improve patient outcomes. The paper thoroughly examines the advantages, limitations, and prospects of various non-invasive approaches, including blood tests, non-blood-based tests, and diverse imaging modalities. It discusses the biomarkers found in blood for early-stage cancer detection, specifying the types of cancer associated with each biomarker. The non-blood-based tests focus on components in saliva, urine, and breath for cancer detection, alongside current studies and future perspectives on various cancers. Optical imaging methods covered in this review include fluorescence imaging in the near-infrared (NIR) region, bioluminescence imaging, and Raman spectroscopy for early-stage cancer detection. The review also highlights the pros and cons of ultrasound imaging in early-stage cancer detection. Additionally, the clinical implications of using AI for cancer detection, both present and future, are explored. This paper provides valuable insights for researchers and clinicians working in the field of non-invasive early-stage cancer detection., Competing Interests: Declarations. Conflicts of interest: The author declares no conflicts of interest., (© 2024. The Author(s).)
- Published
- 2024
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30. Western diet promotes the progression of metabolic dysfunction-associated steatotic liver disease in association with ferroptosis in male mice.
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Maddie N, Chacko N, Matatov D, and Carrillo-Sepulveda MA
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- Animals, Male, Mice, Liver metabolism, Liver pathology, Disease Progression, Lipid Peroxidation, Coenzyme A Ligases metabolism, Oxidative Stress, Ferroptosis, Mice, Inbred C57BL, Non-alcoholic Fatty Liver Disease metabolism, Non-alcoholic Fatty Liver Disease pathology, Non-alcoholic Fatty Liver Disease etiology, Diet, Western adverse effects, Obesity metabolism, Obesity pathology
- Abstract
Non-alcoholic fatty liver disease (NAFLD), now referred to as metabolic dysfunction-associated steatotic liver disease (MASLD), is a silent killer that often progresses to metabolic dysfunction-associated steatohepatitis (MASH). To date, there are no pharmacological treatments for MASLD. While obesity is a major cause of the development and progression of MASLD, the underlying mechanisms remain unclear. We hypothesize that ferroptosis, a recently discovered nonapoptotic iron-dependent form of cell death, is activated during the progression of MASLD and may be a potential target for treating MASLD. Using a murine model of Western diet-induced obesity, C57BL/6J male mice were exposed to a long-term (36 weeks) Western diet. Controls were maintained with a standard chow diet. Western diet-induced obesity was confirmed by increased body mass index (BMI). Histopathological analysis demonstrated the progression of MASLD to MASH in the obese group, which was accompanied by significant hepatic iron deposition, oxidative damage, and lipid peroxidation. Hepatic ferroptosis was further confirmed by decreased protein expression of glutathione peroxidase 4 (GPX4) and increased acyl-CoA synthetase long-chain family member 4 (ACSL4), markers of ferroptosis. These findings suggest that ferroptosis is a potential mechanism involved in the pathogenesis of MASLD in male mice., (© 2024 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)
- Published
- 2024
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31. Barriers to seeking treatment for alcohol use disorders among males in a tertiary care center in South India - a cross-sectional study.
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Veena M, Ruben JP, Chacko Kunjumon N, and Devarbhavi H
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- Humans, Male, India, Cross-Sectional Studies, Adult, Middle Aged, Young Adult, Surveys and Questionnaires, Alcoholism therapy, Alcoholism psychology, Tertiary Care Centers, Patient Acceptance of Health Care psychology, Patient Acceptance of Health Care statistics & numerical data, Health Services Accessibility
- Abstract
Background: There are limited studies on barriers to seeking treatment for Alcohol Use Disorders (AUD) among males in tertiary care centers in India and abroad. Identification of these factors can aid in addressing the barriers to seeking treatment for AUD in low-and-middle-income countries., Objective: To investigate the barriers to seeking treatment for AUD among males in a tertiary care center in South India., Methods: The study design was cross-sectional. We employed a semi-structured interview proforma, Barriers Questionnaire (Alcohol), and assessed the age of onset of initiation of alcohol, problem drinking, and AUD., Results: The majority (73.3%) belonged to Low-Barrier group. Individual items such as "Denial of Alcoholism", "avoid others counseling", "don't like to talk in groups", "Worried about what others will think for taking help or made fun of by others", "Self or Family embarrassed of taking treatment", "cannot afford treatment due to various reasons", "Fear of losing job", "Fear of losing friends" and "Fear of seeing people" were significantly higher in High-Barrier group., Conclusions: Our study has helped to identify some of the important impediments. Psychoeducation and reducing the stereotypes related to the treatment of AUD can increase trust in the treatment process, resulting in greater help-seeking, early intervention, and improved quality of life.
- Published
- 2024
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32. Massage for neck pain contrasted against standard (non-surgical) treatment: A systematic review update.
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Lee H, Gross AR, Chacko N, Ezzo J, Goldsmith CH, Gelley G, Forget M, Lee S, Jeong H, Dixon C, and Santaguida PL
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- Humans, Randomized Controlled Trials as Topic, Pain Measurement, Neck Pain therapy, Massage methods
- Abstract
Objectives: The aim of this systematic review update was to determine the average effect of massage for adults with neck pain (NP) contrasted against another standard treatment., Methods: Randomised controlled trials comparing massage to standard treatments were included; placebo/no treatment comparisons were excluded. Databases were searched (CENTRAL, MEDLINE, EMBASE, CINAHL, ICL, trial registries) from inception to Oct-1-2023. We used the standard Cochrane methodological procedures: rated Risk of Bias 1.0, abstracted mean differences (MD), meta-analysed data, and rated the level of certainty (GRADE)., Results: We included 42 studies (2656 participants; 67% high RoB) contrasted against 10 unique treatments. Trials studied ages 18-70, 70% female, and mean pain severity 52 Visual Analogue Scale (VAS). Very-low to moderate-certainty evidence for pain (MD VAS 0-100, 95% CI) at ≤12 weeks follow-up follows. The pre-stated minimal important difference margin was 10 VAS points. Massage was Massage may not increase risks of minor adverse events: RR 0.37 (95% CI 0.22 to 0.61)., Conclusion: For subacute-chronic NP, pain reduction varied by comparison. The evidence was limited by imprecision and high RoB. Focused planning for adequately dosed longer-term trials is needed., Competing Interests: Declaration of competing interest No conflicts of interest are declared., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2024
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33. Genomic Discovery and Structure-Activity Exploration of a Novel Family of Enzyme-Activated Covalent Cyclin-Dependent Kinase Inhibitors.
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Davison JR, Hadjithomas M, Romeril SP, Choi YJ, Bentley KW, Biggins JB, Chacko N, Castaldi MP, Chan LK, Cumming JN, Downes TD, Eisenhauer EL, Fei F, Fontaine BM, Endalur Gopinarayanan V, Gurnani S, Hecht A, Hosford CJ, Ibrahim A, Jagels A, Joubran C, Kim JN, Lisher JP, Liu DD, Lyles JT, Mannara MN, Murray GJ, Musial E, Niu M, Olivares-Amaya R, Percuoco M, Saalau S, Sharpe K, Sheahan AV, Thevakumaran N, Thompson JE, Thompson DA, Wiest A, Wyka SA, Yano J, and Verdine GL
- Subjects
- Humans, Structure-Activity Relationship, Animals, Genomics methods, Models, Molecular, Protein Kinase Inhibitors pharmacology, Protein Kinase Inhibitors chemistry, Protein Kinase Inhibitors chemical synthesis, Cyclin-Dependent Kinases antagonists & inhibitors, Cyclin-Dependent Kinases metabolism, Drug Discovery
- Abstract
Fungi have historically been the source of numerous important medicinal compounds, but full exploitation of their genetic potential for drug development has been hampered in traditional discovery paradigms. Here we describe a radically different approach, top-down drug discovery (TD
3 ), starting with a massive digital search through a database of over 100,000 fully genomicized fungi to identify loci encoding molecules with a predetermined human target. We exemplify TD3 by the selection of cyclin-dependent kinases (CDKs) as targets and the discovery of two molecules, 1 and 2 , which inhibit therapeutically important human CDKs. 1 and 2 exhibit a remarkable mechanism, forming a site-selective covalent bond to the CDK active site Lys. We explored the structure-activity relationship via semi- and total synthesis, generating an analog, 43 , with improved kinase selectivity, bioavailability, and efficacy. This work highlights the power of TD3 to identify mechanistically and structurally novel molecules for the development of new medicines.- Published
- 2024
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34. Trait Mindfulness and Social Support Predict Lower Perceived Stress Burden in Patients Undergoing Radiation Therapy.
- Author
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Cooper DJ, Eckstein J, Sidiqi B, Rana ZH, Matarangas A, Shah A, Chacko N, Mancuso J, Minutoli T, Zinkin A, Sharma K, Mehta R, Potters L, and Parashar B
- Abstract
Purpose: Cancer diagnosis and treatment, including radiation therapy (RT), cause significant patient stress. Mindfulness and social support have been shown to help manage the psychological effects of cancer treatment. The objective of our study was to determine the sociodemographic and clinical factors associated with stress burden in patients receiving RT., Methods and Materials: Patients receiving RT for cancer at a single institution were given a 3-section survey to complete during the first on-treatment visit. The survey included the Perceived Stress Scale, Medical Outcomes Study Social Support Survey, and Mindfulness Attention Awareness Scale, which were used to measure stress, social support, and trait mindfulness, respectively. Linear regression analysis was performed to determine associations between perceived stress and age, patient sex, race and ethnicity, treatment intent, disease site, trait mindfulness, and social support. Factors significant in univariable analysis were analyzed with a multivariable analysis., Results: A total of 93 patients undergoing RT at a tertiary care academic institution were recruited from July to September 2019. Median scores for Perceived Stress Scale, Medical Outcomes Study Social Support Survey, and Mindfulness Attention Awareness Scale were 14.6 (range, 0-31; SD, 6.9), 4.2 (range, 1-5; SD, 1.0), and 5.1 (range, 3.1-6.0; SD, 0.8), respectively. On univariable analysis, mindfulness and social support were associated with decreased stress burden, and female sex and palliative intent were associated with increased stress burden. These factors all maintained significance in multivariable analysis., Conclusions: These results suggest measures to improve mindfulness and perceived social support, such as mindfulness meditation and psychoeducational approaches, may lessen the stress burden and improve quality of life for patients undergoing RT. Future studies should analyze the longitudinal impact of individual patient characteristics, including patient sex and treatment intent, to better understand their effects on psychological maladjustment during cancer care., Competing Interests: None., (© 2024 The Authors.)
- Published
- 2024
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35. Massage for neck pain.
- Author
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Gross AR, Lee H, Ezzo J, Chacko N, Gelley G, Forget M, Morien A, Graham N, Santaguida PL, Rice M, and Dixon C
- Subjects
- Adult, Female, Humans, Male, Neck Pain etiology, Neck Pain therapy, Neck, Massage, Adjuvants, Immunologic, Post-Traumatic Headache, Radiculopathy
- Abstract
Background: Massage is widely used for neck pain, but its effectiveness remains unclear., Objectives: To assess the benefits and harms of massage compared to placebo or sham, no treatment or exercise as an adjuvant to the same co-intervention for acute to chronic persisting neck pain in adults with or without radiculopathy, including whiplash-associated disorders and cervicogenic headache., Search Methods: We searched multiple databases (CENTRAL, MEDLINE, EMBASE, CINAHL, Index to Chiropractic Literature, trial registries) to 1 October 2023., Selection Criteria: We included randomised controlled trials (RCTs) comparing any type of massage with sham or placebo, no treatment or wait-list, or massage as an adjuvant treatment, in adults with acute, subacute or chronic neck pain., Data Collection and Analysis: We used the standard methodological procedures expected by Cochrane. We transformed outcomes to standardise the direction of the effect (a smaller score is better). We used a partially contextualised approach relative to identified thresholds to report the effect size as slight-small, moderate or large-substantive., Main Results: We included 33 studies (1994 participants analysed). Selection (82%) and detection bias (94%) were common; multiple trials had unclear allocation concealment, utilised a placebo that may not be credible and did not test whether blinding to the placebo was effective. Massage was compared with placebo (n = 10) or no treatment (n = 8), or assessed as an adjuvant to the same co-treatment (n = 15). The trials studied adults aged 18 to 70 years, 70% female, with mean pain severity of 51.8 (standard deviation (SD) 14.1) on a visual analogue scale (0 to 100). Neck pain was subacute-chronic and classified as non-specific neck pain (85%, including n = 1 whiplash), radiculopathy (6%) or cervicogenic headache (9%). Trials were conducted in outpatient settings in Asia (n = 11), America (n = 5), Africa (n = 1), Europe (n = 12) and the Middle East (n = 4). Trials received research funding (15%) from research institutes. We report the main results for the comparison of massage versus placebo. Low-certainty evidence indicates that massage probably results in little to no difference in pain, function-disability and health-related quality of life when compared against a placebo for subacute-chronic neck pain at up to 12 weeks follow-up. It may slightly improve participant-reported treatment success. Subgroup analysis by dose showed a clinically important difference favouring a high dose (≥ 8 sessions over four weeks for ≥ 30 minutes duration). There is very low-certainty evidence for total adverse events. Data on patient satisfaction and serious adverse events were not available. Pain was a mean of 20.55 points with placebo and improved by 3.43 points with massage (95% confidence interval (CI) 8.16 better to 1.29 worse) on a 0 to 100 scale, where a lower score indicates less pain (8 studies, 403 participants; I
2 = 39%). We downgraded the evidence to low-certainty due to indirectness; most trials in the placebo comparison used suboptimal massage doses (only single sessions). Selection, performance and detection bias were evident as multiple trials had unclear allocation concealment, utilised a placebo that may not be credible and did not test whether blinding was effective, respectively. Function-disability was a mean of 30.90 points with placebo and improved by 9.69 points with massage (95% CI 17.57 better to 1.81 better) on the Neck Disability Index 0 to 100, where a lower score indicates better function (2 studies, 68 participants; I2 = 0%). We downgraded the evidence to low-certainty due to imprecision (the wide CI represents slight to moderate benefit that does not rule in or rule out a clinically important change) and risk of selection, performance and detection biases. Participant-reported treatment success was a mean of 3.1 points with placebo and improved by 0.80 points with massage (95% CI 1.39 better to 0.21 better) on a Global Improvement 1 to 7 scale, where a lower score indicates very much improved (1 study, 54 participants). We downgraded the evidence to low-certainty due to imprecision (single study with a wide CI that does not rule in or rule out a clinically important change) and risk of performance as well as detection bias. Health-related quality of life was a mean of 43.2 points with placebo and improved by 5.30 points with massage (95% CI 8.24 better to 2.36 better) on the SF-12 (physical) 0 to 100 scale, where 0 indicates the lowest level of health (1 study, 54 participants). We downgraded the evidence once for imprecision (a single small study) and risk of performance and detection bias. We are uncertain whether massage results in increased total adverse events, such as treatment soreness, sweating or low blood pressure (RR 0.99, 95% CI 0.08 to 11.55; 2 studies, 175 participants; I2 = 77%). We downgraded the evidence to very low-certainty due to unexplained inconsistency, risk of performance and detection bias, and imprecision (the CI was extremely wide and the total number of events was very small, i.e < 200 events)., Authors' Conclusions: The contribution of massage to the management of neck pain remains uncertain given the predominance of low-certainty evidence in this field. For subacute and chronic neck pain (closest to 12 weeks follow-up), massage may result in a little or no difference in improving pain, function-disability, health-related quality of life and participant-reported treatment success when compared to a placebo. Inadequate reporting on adverse events precluded analysis. Focused planning for larger, adequately dosed, well-designed trials is needed., (Copyright © 2024 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)- Published
- 2024
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36. Au nanodyes as enhanced contrast agents in wide field near infrared fluorescence lifetime imaging.
- Author
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Chacko N, Motiei M, Suryakant JS, Firer M, and Ankri R
- Abstract
The near-infrared (NIR) range of the electromagnetic (EM) spectrum offers a nearly transparent window for imaging tissue. Despite the significant potential of NIR fluorescence-based imaging, its establishment in basic research and clinical applications remains limited due to the scarcity of fluorescent molecules with absorption and emission properties in the NIR region, especially those suitable for biological applications. In this study, we present a novel approach by combining the widely used IRdye 800NHS fluorophore with gold nanospheres (GNSs) and gold nanorods (GNRs) to create Au nanodyes, with improved quantum yield (QY) and distinct lifetimes. These nanodyes exhibit varying photophysical properties due to the differences in the separation distance between the dye and the gold nanoparticles (GNP). Leveraging a rapid and highly sensitive wide-field fluorescence lifetime imaging (FLI) macroscopic set up, along with phasor based analysis, we introduce multiplexing capabilities for the Au nanodyes. Our approach showcases the ability to differentiate between NIR dyes with very similar, short lifetimes within a single image, using the combination of Au nanodyes and wide-field FLI. Furthermore, we demonstrate the uptake of Au nanodyes by mineral-oil induced plasmacytomas (MOPC315.bm) cells, indicating their potential for in vitro and in vivo applications., (© 2024. The Author(s).)
- Published
- 2024
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37. Clinical features and risk factors for death in acute undifferentiated fever: A prospective observational study in rural community hospitals in six states of India.
- Author
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Mørch K, Manoharan A, Chandy S, Singh A, Kuriakose C, Patil S, Henry A, Chacko N, Alvarez-Uria G, Nesaraj J, Blomberg B, Kurian S, Haanshuus CG, Antony GV, Langeland N, and Mathai D
- Subjects
- Humans, Hospitals, Community, Oliguria, Fever etiology, Risk Factors, India epidemiology, Malaria diagnosis, Sepsis complications, Scrub Typhus diagnosis
- Abstract
Background: Acute undifferentiated fever (AUF) ranges from self-limiting illness to life-threatening infections, such as sepsis, malaria, dengue, leptospirosis and rickettsioses. Similar clinical presentation challenges the clinical management. This study describes risk factors for death in patients hospitalized with AUF in India., Methods: Patients aged ≥5 y admitted with fever for 2-14 d without localizing signs were included in a prospective observational study at seven hospitals in India during 2011-2012. Predictors identified by univariate analysis were analyzed by multivariate logistic regression for survival analysis., Results: Mortality was 2.4% (37/1521) and 46.9% (15/32) died within 2 d. History of heart disease (p=0.013), steroid use (p=0.011), altered consciousness (p<0.0001), bleeding (p<0.0001), oliguria (p=0.020) and breathlessness (p=0.015) were predictors of death, as were reduced Glasgow coma score (p=0.005), low urinary output (p=0.004), abnormal breathing (p=0.006), abdominal tenderness (p=0.023), leucocytosis (p<0.0001) and thrombocytopenia (p=0.001) at admission. Etiology was identified in 48.6% (18/37) of fatal cases., Conclusions: Bleeding, cerebral dysfunction, respiratory failure and oliguria at admission, suggestive of severe organ failure secondary to systemic infection, were predictors of death. Almost half of the patients who died, died shortly after admission, which, together with organ failure, suggests that delay in hospitalization and, consequently, delayed treatment, contribute to death from AUF., (© The Author(s) 2022. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.)
- Published
- 2023
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38. Cloning and sequence analysis of a partial CDS of leptospiral ligA gene in pET-32a - Escherichia coli DH5α system.
- Author
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Soman M, Mini M, Joseph S, Thomas J, Chacko N, Sumithra TG, Ambily R, Mani BK, and Balan R
- Abstract
Aim: This study aims at cloning, sequencing, and phylogenetic analysis of a partial CDS of ligA gene in pET-32a - Escherichia coli DH5α system, with the objective of identifying the conserved nature of the ligA gene in the genus Leptospira ., Materials and Methods: A partial CDS (nucleotide 1873 to nucleotide 3363) of the ligA gene was amplified from genomic DNA of Leptospira interrogans serovar Canicola by polymerase chain reaction (PCR). The PCR-amplified DNA was cloned into pET-32a vector and transformed into competent E. coli DH5α bacterial cells. The partial ligA gene insert was sequenced and the nucleotide sequences obtained were aligned with the published ligA gene sequences of other Leptospira serovars, using nucleotide BLAST, NCBI. Phylogenetic analysis of the gene sequence was done by maximum likelihood method using Mega 6.06 software., Results: The PCR could amplify the 1491 nucleotide sequence spanning from nucleotide 1873 to nucleotide 3363 of the ligA gene and the partial ligA gene could be successfully cloned in E. coli DH5α cells. The nucleotide sequence when analyzed for homology with the reported gene sequences of other Leptospira serovars was found to have 100% homology to the 1910 bp to 3320 bp sequence of ligA gene of L. interrogans strain Kito serogroup Canicola. The predicted protein consisted of 470 aminoacids. Phylogenetic analysis revealed that the ligA gene was conserved in L.interrogans species., Conclusion: The partial ligA gene could be successfully cloned and sequenced from E. coli DH5α cells. The sequence showed 100% homology to the published ligA gene sequences. The phylogenetic analysis revealed the conserved nature of the ligA gene. Further studies on the expression and immunogenicity of the partial LigA protein need to be carried out to determine its competence as a subunit vaccine candidate.
- Published
- 2018
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39. Acute undifferentiated fever in India: a multicentre study of aetiology and diagnostic accuracy.
- Author
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Mørch K, Manoharan A, Chandy S, Chacko N, Alvarez-Uria G, Patil S, Henry A, Nesaraj J, Kuriakose C, Singh A, Kurian S, Gill Haanshuus C, Langeland N, Blomberg B, Vasanthan Antony G, and Mathai D
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Bacteremia epidemiology, Bacteremia etiology, Chikungunya Fever diagnosis, Chikungunya Fever epidemiology, Child, Child, Preschool, Coinfection epidemiology, Dengue diagnosis, Dengue epidemiology, Diagnostic Tests, Routine, Female, Fever diagnosis, Fever epidemiology, Humans, India epidemiology, Leptospira pathogenicity, Leptospirosis diagnosis, Leptospirosis epidemiology, Malaria diagnosis, Malaria epidemiology, Male, Middle Aged, Scrub Typhus diagnosis, Scrub Typhus epidemiology, Fever etiology
- Abstract
Background: The objectives of this study were to determine the proportion of malaria, bacteraemia, scrub typhus, leptospirosis, chikungunya and dengue among hospitalized patients with acute undifferentiated fever in India, and to describe the performance of standard diagnostic methods., Methods: During April 2011-November 2012, 1564 patients aged ≥5 years with febrile illness for 2-14 days were consecutively included in an observational study at seven community hospitals in six states in India. Malaria microscopy, blood culture, Dengue rapid NS1 antigen and IgM Combo test, Leptospira IgM ELISA, Scrub typhus IgM ELISA and Chikungunya IgM ELISA were routinely performed at the hospitals. Second line testing, Dengue IgM capture ELISA (MAC-ELISA), Scrub typhus immunofluorescence (IFA), Leptospira Microscopic Agglutination Test (MAT), malaria PCR and malaria immunochromatographic rapid diagnostic test (RDT) Parahit Total™ were performed at the coordinating centre. Convalescence samples were not available. Case definitions were as follows: Leptospirosis: Positive ELISA and positive MAT. Scrub typhus: Positive ELISA and positive IFA. Dengue: Positive RDT and/or positive MAC-ELISA. Chikungunya: Positive ELISA. Bacteraemia: Growth in blood culture excluding those defined as contaminants. Malaria: Positive genus-specific PCR., Results: Malaria was diagnosed in 17% (268/1564) and among these 54% had P. falciparum. Dengue was diagnosed in 16% (244/1564). Bacteraemia was found in 8% (124/1564), and among these Salmonella typhi or S. paratyphi constituted 35%. Scrub typhus was diagnosed in 10%, leptospirosis in 7% and chikungunya in 6%. Fulfilling more than one case definition was common, most frequent in chikungunya where 26% (25/98) also had positive dengue test., Conclusions: Malaria and dengue were the most common causes of fever in this study. A high overlap between case definitions probably reflects high prevalence of prior infections, cross reactivity and subclinical infections, rather than high prevalence of coinfections. Low accuracy of routine diagnostic tests should be taken into consideration when approaching the patient with acute undifferentiated fever in India.
- Published
- 2017
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40. Production of recombinant non-structural protein-3 hydrophobic domain deletion (NS3ΔHD) protein of bluetongue virus from prokaryotic expression system as an efficient diagnostic reagent.
- Author
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Mohanty NN, Chacko N, Biswas SK, Chand K, Pandey AB, Mondal B, Hemadri D, and Shivachandra SB
- Subjects
- Animals, Bluetongue diagnosis, Bluetongue immunology, Escherichia coli, Gene Expression, Recombinant Fusion Proteins chemistry, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins immunology, Ruminants immunology, Ruminants virology, Amino Acid Sequence, Bluetongue virus chemistry, Bluetongue virus genetics, Bluetongue virus immunology, Sequence Deletion, Viral Nonstructural Proteins chemistry, Viral Nonstructural Proteins genetics, Viral Nonstructural Proteins immunology
- Abstract
Serological diagnostics for bluetongue (BT), which is an infectious, non-contagious and arthropod-borne virus disease of ruminants, are primarily dependent on availability of high quality native or recombinant antigen(s) based on either structural/non-structural proteins in sufficient quantity. Non-structural proteins (NS1-NS4) of BT virus are presumed candidate antigens in development of DIVA diagnostics. In the present study, NS3 fusion gene encoding for NS3 protein containing the N- and C-termini with a deletion of two hydrophobic domains (118A to S141 aa and 162S to A182 aa) and intervening variable central domain (142D to K161 aa) of bluetongue virus 23 was constructed, cloned and over-expressed using prokaryotic expression system. The recombinant NS3ΔHD fusion protein (∼38 kDa) including hexa-histidine tag on its both termini was found to be non-cytotoxic to recombinant Escherichia coli cells and purified by affinity chromatography. The purified rNS3ΔHD fusion protein was found to efficiently detect BTV-NS3 specific antibodies in indirect-ELISA format with diagnostic sensitivity (DSn = 94.4%) and specificity (DSp = 93.9%). The study indicated the potential utility of rNS3ΔHD fusion protein as candidate diagnostic reagent in developing an indirect-ELISA for sero-surveillance of animals for BTV antibodies under DIVA strategy, wherever monovalent/polyvalent killed BT vaccine formulations devoid of NS proteins are being practiced for immunization., (Copyright © 2016 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2016
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41. The lncRNA RZE1 Controls Cryptococcal Morphological Transition.
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Chacko N, Zhao Y, Yang E, Wang L, Cai JJ, and Lin X
- Subjects
- Cryptococcus neoformans genetics, Cryptococcus neoformans metabolism, Fungal Proteins genetics, Fungal Proteins metabolism, Gene Deletion, Introns, RNA Splicing, Subcellular Fractions metabolism, Cryptococcus neoformans growth & development, Genes, Fungal, RNA, Long Noncoding genetics
- Abstract
In the fungal pathogen Cryptococcus neoformans, the switch from yeast to hypha is an important morphological process preceding the meiotic events during sexual development. Morphotype is also known to be associated with cryptococcal virulence potential. Previous studies identified the regulator Znf2 as a key decision maker for hypha formation and as an anti-virulence factor. By a forward genetic screen, we discovered that a long non-coding RNA (lncRNA) RZE1 functions upstream of ZNF2 in regulating yeast-to-hypha transition. We demonstrate that RZE1 functions primarily in cis and less effectively in trans. Interestingly, RZE1's function is restricted to its native nucleus. Accordingly, RZE1 does not appear to directly affect Znf2 translation or the subcellular localization of Znf2 protein. Transcriptome analysis indicates that the loss of RZE1 reduces the transcript level of ZNF2 and Znf2's prominent downstream targets. In addition, microscopic examination using single molecule fluorescent in situ hybridization (smFISH) indicates that the loss of RZE1 increases the ratio of ZNF2 transcripts in the nucleus versus those in the cytoplasm. Taken together, this lncRNA controls Cryptococcus yeast-to-hypha transition through regulating the key morphogenesis regulator Znf2. This is the first functional characterization of a lncRNA in a human fungal pathogen. Given the potential large number of lncRNAs in the genomes of Cryptococcus and other fungal pathogens, the findings implicate lncRNAs as an additional layer of genetic regulation during fungal development that may well contribute to the complexity in these "simple" eukaryotes.
- Published
- 2015
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42. Early urinary diversion with ileal conduit and vesicovaginostomy in the treatment of radiation cystitis due to carcinoma cervix: a study from a tertiary care hospital in South India.
- Author
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Banerji JS, Devasia A, Kekre NS, and Chacko N
- Subjects
- Adult, Aged, Cervix Uteri pathology, Cervix Uteri surgery, Cost-Benefit Analysis, Cystitis etiology, Female, Follow-Up Studies, Humans, Middle Aged, Quality of Life, Radiation Injuries etiology, Radiotherapy adverse effects, Retrospective Studies, Tertiary Healthcare, Transfusion Medicine methods, Uterine Cervical Neoplasms surgery, Vagina surgery, Carcinoma complications, Carcinoma radiotherapy, Carcinoma surgery, Cervix Uteri radiation effects, Cystitis surgery, Cystostomy methods, Radiation Injuries surgery, Urinary Diversion methods, Uterine Cervical Neoplasms radiotherapy
- Abstract
Background: To study the magnitude of radiation cystitis following radiation therapy for carcinoma cervix, and propose an algorithm to decide on early diversion, with or without vesicovaginostomy., Methods: Women who developed radiation cystitis following radiotherapy for carcinoma cervix from January 1998 to December 2011 were included in this retrospective study. Electronic hospital records were analysed to document the presence of radiation cystitis. All women who developed evidence of radiation-induced cystitis, according to the common toxicity and Radiation Therapy Oncology Group criteria, were included in the study. We looked at transfusion requirements, number of hospital admissions, quality of life and cost involved. Chi-square tests were done where applicable. SPSS version 16 was used for analysis., Results: Of the 902 patients who received radiation for carcinoma cervix in the 13-year period, 62 (6.87%) developed grade 3/4 cystitis. Twenty-eight of them underwent ileal conduit diversion, with 18 undergoing concomitant vesicovaginostomy. When compared with the patients who did not have diversion, the transfusion requirements, number of hospital admissions and quality of life had a statistically significant difference. Cost analysis of early diversion too showed a marginal benefit with early diversion. The limitation of the study was that it was retrospective in nature., Conclusion: In radiation cystitis, multiple hospital admissions and consequential increase in cost is the norm. In severe disease, early diversion is a prudent, cost-effective approach with good quality of life and early return to normal activity., (© 2014 Royal Australasian College of Surgeons.)
- Published
- 2015
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43. A coiled-coil motif in non-structural protein 3 (NS3) of bluetongue virus forms an oligomer.
- Author
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Chacko N, Mohanty NN, Biswas SK, Chand K, Yogisharadhya R, Pandey AB, Mondal B, and Shivachandra SB
- Subjects
- Computational Biology, Electrophoresis, Polyacrylamide Gel, Protein Binding, Protein Conformation, Protein Interaction Domains and Motifs, Sequence Analysis, DNA, Viral Nonstructural Proteins chemistry, Bluetongue virus physiology, Protein Multimerization, Viral Nonstructural Proteins genetics, Viral Nonstructural Proteins metabolism
- Abstract
Bluetongue, an arthropod-borne non-contagious hemorrhagic disease of small ruminants, is caused by bluetongue virus (BTV). Several structural and non-structural proteins encoded by BTV have been associated with virulence mechanisms. In the present study, the NS3 protein sequences of bluetongue viral serotypes were analyzed for the presence of heptad regions and oligomer formation. Bioinformatic analysis of NS3 sequences of all 26 BTV serotypes revealed the presence of at least three coiled-coil motifs (CCMs). A conserved α-helical heptad sequence was identified at 14-26 aa (CCM-I), 185-198aa (CCM-II), and 94-116 aa (CCM-III). Among these, CCM-I occurs close to the N-terminus of NS3 and was presumed to be involved in oligomerization. Furthermore, the N-terminus of NS3 (1M-R117 aa) was over-expressed as a recombinant fusion protein in a prokaryotic expression system. Biochemical characterization of recombinant NS3Nt protein revealed that it forms SDS-resistant dimers and high-order oligomers (hexamer and/or octamer) under reducing or non-reducing conditions. Coiled-coil motifs are believed to be critical for NS protein oligomerization and have potential roles in the formation of viroporin ring/pore either with six/eight subunits and this is the first study toward characterization of CCMs in NS3 of bluetongue virus.
- Published
- 2015
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44. Developmental Alterations in Heart Biomechanics and Skeletal Muscle Function in Desmin Mutants Suggest an Early Pathological Root for Desminopathies.
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Ramspacher C, Steed E, Boselli F, Ferreira R, Faggianelli N, Roth S, Spiegelhalter C, Messaddeq N, Trinh L, Liebling M, Chacko N, Tessadori F, Bakkers J, Laporte J, Hnia K, and Vermot J
- Subjects
- Animals, Biomechanical Phenomena, Cardiomyopathies pathology, Cytoskeleton metabolism, Cytoskeleton pathology, Humans, Muscular Dystrophies pathology, Mutation, Zebrafish, Cardiomyopathies genetics, Desmin genetics, Desmin metabolism, Heart physiology, Muscle, Skeletal physiology, Muscular Dystrophies genetics
- Abstract
Desminopathies belong to a family of muscle disorders called myofibrillar myopathies that are caused by Desmin mutations and lead to protein aggregates in muscle fibers. To date, the initial pathological steps of desminopathies and the impact of desmin aggregates in the genesis of the disease are unclear. Using live, high-resolution microscopy, we show that Desmin loss of function and Desmin aggregates promote skeletal muscle defects and alter heart biomechanics. In addition, we show that the calcium dynamics associated with heart contraction are impaired and are associated with sarcoplasmic reticulum dilatation as well as abnormal subcellular distribution of Ryanodine receptors. Our results demonstrate that desminopathies are associated with perturbed excitation-contraction coupling machinery and that aggregates are more detrimental than Desmin loss of function. Additionally, we show that pharmacological inhibition of aggregate formation and Desmin knockdown revert these phenotypes. Our data suggest alternative therapeutic approaches and further our understanding of the molecular determinants modulating Desmin aggregate formation., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
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45. Generation of stable mutants and targeted gene deletion strains in Cryptococcus neoformans through electroporation.
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Lin X, Chacko N, Wang L, and Pavuluri Y
- Subjects
- Genomic Instability, Homologous Recombination, Cryptococcus neoformans genetics, Electroporation methods, Gene Deletion, Gene Knockout Techniques methods, Genetics, Microbial methods
- Abstract
Cryptococcus neoformans is the etiologic agent of cryptococcal meningitis that causes more than half a million deaths worldwide each year. This capsulated basidiomycetous yeast also serves as a model for micropathogenic studies. The ability to make stable mutants, either via ectopic integration or homologous recombination, has been accomplished using biolistic transformation. This technical advance has greatly facilitated the research on the basic biology and pathogenic mechanisms of this pathogen in the past two decades. However, biolistic transformation is costly, and its reproducibility varies widely. Here we found that stable ectopic integration or targeted gene deletion via homologous replacement could be accomplished through electroporative transformation. The stability of the transformants obtained through electroporation and the frequency of homologous replacement is highly dependent on the selective marker. A frequency of homologous recombination among the stable transformants obtained by electroporation is comparable to those obtained by biolistic transformation (∼10%) when dominant drug selection markers are used, which is much higher than what has been previously reported for electroporation when auxotrophic markers were used (0.001% to 0.1%). Furthermore, disruption of the KU80 gene or generation of gene deletion constructs using the split marker strategy, two approaches known to increase homologous replacement among transformants obtained through biolistic transformation, also increase the frequency of homologous replacement among transformants obtained through electroporation. Therefore, electroporation provides a low cost alternative for mutagenesis in Cryptococcus., (© The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2015
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46. Transcriptome Analysis of a Ustilago maydis ust1 Deletion Mutant Uncovers Involvement of Laccase and Polyketide Synthase Genes in Spore Development.
- Author
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Islamovic E, García-Pedrajas MD, Chacko N, Andrews DL, Covert SF, and Gold SE
- Subjects
- Cell Wall metabolism, Fungal Proteins genetics, Fungal Proteins metabolism, Gene Expression Profiling, Laccase metabolism, Models, Biological, Oligonucleotide Array Sequence Analysis, Pigmentation, Polyketide Synthases metabolism, Seedlings microbiology, Sequence Deletion, Spores, Fungal, Ustilago genetics, Ustilago growth & development, Ustilago pathogenicity, Virulence, Laccase genetics, Plant Diseases microbiology, Polyketide Synthases genetics, Transcriptome, Ustilago enzymology, Zea mays microbiology
- Abstract
Ustilago maydis, causal agent of corn smut disease, is a dimorphic fungus alternating between a saprobic budding haploid and an obligate pathogenic filamentous dikaryon. Maize responds to U. maydis colonization by producing tumorous structures, and only within these does the fungus sporulate, producing melanized sexual teliospores. Previously we identified Ust1, an APSES (Asm1p, Phd1p, Sok2p, Efg1p, and StuAp) transcription factor, whose deletion led to filamentous haploid growth and the production of highly pigmented teliospore-like structures in culture. In this study, we analyzed the transcriptome of a ust1 deletion mutant and functionally characterized two highly upregulated genes with potential roles in melanin biosynthesis: um05361, encoding a putative laccase (lac1), and um06414, encoding a polyketide synthase (pks1). The Δlac1 mutant strains showed dramatically reduced virulence on maize seedlings and fewer, less-pigmented teliospores in adult plants. The Δpks1 mutant was unaffected in seedling virulence but adult plant tumors generated hyaline, nonmelanized teliospores. Thus, whereas pks1 appeared to be restricted to the synthesis of melanin, lac1 showed a broader role in virulence. In conclusion, the ust1 deletion mutant provided an in vitro model for sporulation in U. maydis, and functional analysis supports the efficacy of this in vitro mutant analysis for identification of genes involved in in planta teliosporogenesis.
- Published
- 2015
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47. Homogeneity of VacJ outer membrane lipoproteins among Pasteurella multocida strains and heterogeneity among members of Pasteurellaceae.
- Author
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Shivachandra SB, Kumar A, Mohanty NN, Yogisharadhya R, Chacko N, Viswas KN, and Ramakrishnan MA
- Subjects
- Amino Acid Sequence, Base Sequence, Computational Biology, DNA, Bacterial chemistry, DNA, Bacterial genetics, Molecular Sequence Data, Polymerase Chain Reaction veterinary, Sequence Alignment, Sequence Analysis, DNA, Genetic Variation genetics, Pasteurella multocida genetics, Phylogeny, Virulence Factors genetics
- Abstract
Outer membrane lipoproteins are widely distributed in Gram-negative bacteria which are involved in diverse mechanisms of physiology/pathogenesis. Various pathogenic bacterial strains belonging to the family-Pasteurellaceae have several surface exposed virulence factors including VacJ/VacJ-like lipoproteins. In the present study, vacJ gene encoding for VacJ outer membrane lipoprotein of different Pasteurella multocida strains (n = 10) were amplified, sequenced and compared with available VacJ/VacJ-like sequences (n = 45) of Pasteurellaceae members. Comparative multiple sequence analysis at amino acid level indicated absolute homogeneity of VacJ lipoprotein among different P. multocida strains. However, heterogeneity (18.0-89.9%) of VacJ lipoprotein was noticed among members of Pasteurellaceae. A predicted lipobox motif (L-3-[A/S/T/V]-2-[G/A]-1-C) was found to be conserved between 12-32aa residues at N-terminus among all VacJ sequences. Bioinformatic analysis indicated that VacJ is a chromosomal gene product exposed on the bacterial surface, possibly essential for either physiological or pathogenicity process of Pasteurellae and distributed widely among P. multocida serogroups. The study indicated potential possibilities of using absolutely conserved VacJ lipoprotein either as 'signature gene/protein' in developing diagnostic assay or as a recombinant subunit vaccine for P. multocida infections in livestock., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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48. Discretization of continuous convolution operators for accurate modeling of wave propagation in digital holography.
- Author
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Chacko N, Liebling M, and Blu T
- Abstract
Discretization of continuous (analog) convolution operators by direct sampling of the convolution kernel and use of fast Fourier transforms is highly efficient. However, it assumes the input and output signals are band-limited, a condition rarely met in practice, where signals have finite support or abrupt edges and sampling is nonideal. Here, we propose to approximate signals in analog, shift-invariant function spaces, which do not need to be band-limited, resulting in discrete coefficients for which we derive discrete convolution kernels that accurately model the analog convolution operator while taking into account nonideal sampling devices (such as finite fill-factor cameras). This approach retains the efficiency of direct sampling but not its limiting assumption. We propose fast forward and inverse algorithms that handle finite-length, periodic, and mirror-symmetric signals with rational sampling rates. We provide explicit convolution kernels for computing coherent wave propagation in the context of digital holography. When compared to band-limited methods in simulations, our method leads to fewer reconstruction artifacts when signals have sharp edges or when using nonideal sampling devices.
- Published
- 2013
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49. Non-coding RNAs in the development and pathogenesis of eukaryotic microbes.
- Author
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Chacko N and Lin X
- Subjects
- Fungi genetics, Fungi metabolism, Humans, Mycoses genetics, Mycoses metabolism, Plant Diseases genetics, RNA, Fungal metabolism, RNA, Untranslated metabolism, Fungi growth & development, Fungi pathogenicity, Mycoses microbiology, Plant Diseases microbiology, RNA, Fungal genetics, RNA, Untranslated genetics
- Abstract
RNA has long been regarded as the important intermediary in the central dogma of gene expression. Recently, the importance of RNAs in the regulation of gene expression became evident with the identification and characterization of non-protein coding transcripts named non-coding RNAs (ncRNAs). The ncRNAs, small and long, are ubiquitously present in all three domains of life and are being recognized for their important roles in genome defense and development. Some of the ncRNAs have been associated with diseases, and therefore, they offer diagnostic and therapeutic potential. In this mini-review, we have highlighted some recent research on the ncRNAs identified in eukaryotic microbes, with special emphasis on fungi that are pathogenic to humans or plants when possible. It is our contention that further elucidation and understanding of ncRNAs will advance our understanding of the development and pathogenesis of eukaryotic microbes and offer alternatives in the diagnosis and treatment of the diseases caused by these pathogens.
- Published
- 2013
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50. Symptomatic lymphocoeles post renal transplant.
- Author
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Choudhrie AV, Kumar S, Gnanaraj L, Devasia A, Chacko N, and Kekre NS
- Subjects
- Adult, Catheters, Humans, Incidence, India epidemiology, Lymphocele epidemiology, Lymphocele surgery, Middle Aged, Recurrence, Retrospective Studies, Suction, Treatment Outcome, Drainage adverse effects, Drainage instrumentation, Drainage methods, Kidney Transplantation adverse effects, Laparoscopy adverse effects, Lymphocele therapy, Nephrostomy, Percutaneous adverse effects, Sclerotherapy adverse effects
- Abstract
The aim of this study was to evaluate the outcome of various treatment modalities of symptomatic lymphoceles and suggest an optimal management protocol. Case records of 744 renal transplant recipients who underwent surgery between January 2000 and December 2007 were retrospectively reviewed. There were a total of 36 (4.38%) lymphoceles detected in the postoperative period, of which 14 (1.88%) were symptomatic. A total of 32 procedures for the treatment of lymphocele were performed in 14 of these patients. Aspiration or percutaneous catheter drainage was performed as a primary procedure in all cases. Open marsupialization and laparoscopic marsupialization procedures were performed as secondary treatments. Percutaneous nephrostomy was required in one case before definitive treatment. Primary aspiration was successful in (n = 2) 28.5% and percutaneous drainage in (n = 3) 42.8%. Sclerotherapy was definitive in (n = 2 of 3) 66.6%. Seven of 14 patients required secondary procedure. Laparoscopic marsupialization was successful in (n = 4 of 5) 80% and open technique (n = 3) was curative in all cases. In our opinion, the first step in the management of symptomatic lymphocele in post-renal transplant recipients should be percutaneous drainage with or without drug instillation. This can stabilize renal function and optimize patients who may require surgery. Surgical marsupialization offers superior definitive treatment of lymphoceles with the least recurrence rates.
- Published
- 2012
- Full Text
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