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Lindley RI, Anderson CS, Billot L, Forster A, Hackett ML, Harvey LA, Jan S, Li Q, Liu H, Langhorne P, Maulik PK, Murthy GVS, Walker MF, Pandian JD, Alim M, Felix C, Syrigapu A, Tugnawat DK, Verma SJ, Shamanna BR, Hankey G, Thrift A, Bernhardt J, Mehndiratta MM, Jeyaseelan L, Donnelly P, Byrne D, Steley S, Santhosh V, Chilappagari S, Mysore J, Roy J, Padma MV, John L, Aaron S, Borah NC, Vijaya P, Kaul S, Khurana D, Sylaja PN, Halprashanth DS, Madhusudhan BK, Nambiar V, Sureshbabu S, Khanna MC, Narang GS, Chakraborty D, Chakraborty SS, Biswas B, Kaura S, Koundal H, Singh P, Andrias A, Thambu DS, Ramya I, George J, Prabhakar AT, Kirubakaran P, Anbalagan P, Ghose M, Bordoloi K, Gohain P, Reddy NM, Reddy KV, Rao TNM, Alladi S, Jalapu VRR, Manchireddy K, Rajan A, Mehta S, Katoch C, Das B, Jangir A, Kaur T, Sreedharan S, Sivasambath S, Dinesh S, Shibi BS, Thangaraj A, Karunanithi A, Sulaiman SMS, Dehingia K, Das K, Nandini C, Thomas NJ, Dhanya TS, Thomas N, Krishna R, Aneesh V, Krishna R, Khullar S, Thouman S, Sebastian I. Family-led rehabilitation after stroke in India (ATTEND): a randomised controlled trial. Lancet 2017; 390:588-599. [PMID: 28666682 DOI: 10.1016/s0140-6736(17)31447-2] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/17/2017] [Accepted: 04/04/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Most people with stroke in India have no access to organised rehabilitation services. The effectiveness of training family members to provide stroke rehabilitation is uncertain. Our primary objective was to determine whether family-led stroke rehabilitation, initiated in hospital and continued at home, would be superior to usual care in a low-resource setting. METHODS The Family-led Rehabilitation after Stroke in India (ATTEND) trial was a prospectively randomised open trial with blinded endpoint done across 14 hospitals in India. Patients aged 18 years or older who had had a stroke within the past month, had residual disability and reasonable expectation of survival, and who had an informal family-nominated caregiver were randomly assigned to intervention or usual care by site coordinators using a secure web-based system with minimisation by site and stroke severity. The family members of participants in the intervention group received additional structured rehabilitation training-including information provision, joint goal setting, carer training, and task-specific training-that was started in hospital and continued at home for up to 2 months. The primary outcome was death or dependency at 6 months, defined by scores 3-6 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) as assessed by masked observers. Analyses were by intention to treat. This trial is registered with Clinical Trials Registry-India (CTRI/2013/04/003557), Australian New Zealand Clinical Trials Registry (ACTRN12613000078752), and Universal Trial Number (U1111-1138-6707). FINDINGS Between Jan 13, 2014, and Feb 12, 2016, 1250 patients were randomly assigned to intervention (n=623) or control (n=627) groups. 33 patients were lost to follow-up (14 intervention, 19 control) and five patients withdrew (two intervention, three control). At 6 months, 285 (47%) of 607 patients in the intervention group and 287 (47%) of 605 controls were dead or dependent (odds ratio 0·98, 95% CI 0·78-1·23, p=0·87). 72 (12%) patients in the intervention group and 86 (14%) in the control group died (p=0·27), and we observed no difference in rehospitalisation (89 [14%]patients in the intervention group vs 82 [13%] in the control group; p=0·56). We also found no difference in total non-fatal events (112 events in 82 [13%] intervention patients vs 110 events in 79 [13%] control patients; p=0·80). INTERPRETATION Although task shifting is an attractive solution for health-care sustainability, our results do not support investment in new stroke rehabilitation services that shift tasks to family caregivers, unless new evidence emerges. A future avenue of research should be to investigate the effects of task shifting to health-care assistants or team-based community care. FUNDING The National Health and Medical Research Council of Australia.
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Multicenter Study |
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Yadav JS, Reddy BVS, Gupta MK, Prabhakar A, Jagadeesh B. First example of ring expansion of activated quinolines and isoquinolines: novel benzoazepinesElectronic supplementary information (ESI) available: experimental section. See http://www.rsc.org/suppdata/cc/b4/b405100a/. Chem Commun (Camb) 2004:2124-5. [PMID: 15368006 DOI: 10.1039/b405100a] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Activated quinoline and isoquinoline undergo unexpected ring expansion by diazocarbonyl compounds via C-C insertion in the presence of 5 mol% of copper triflate to produce ethyl 1H-benzo[b]azepine-1-carboxylate and ethyl 3H-benzo[d]azepine-3-carboxylate, respectively, in excellent yields with a high degree of selectivity
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Aaron S, Shyamkumar NK, Alexander S, Babu PS, Prabhakar AT, Moses V, Murthy TV, Alexander M. Mechanical thrombectomy for acute ischemic stroke in pregnancy using the penumbra system. Ann Indian Acad Neurol 2016; 19:261-3. [PMID: 27293343 PMCID: PMC4888695 DOI: 10.4103/0972-2327.173302] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Even though intravenous thrombolysis with tissue plasminogen activator (IV tPA) is the standard of care in acute ischemic stroke, its use in pregnancy is not clearly defined. Mechanical thrombectomy devices can be an option; however, literature on the use of such mechanical devices in stroke in pregnancy is lacking. Here we describe two cases that developed acute embolic stroke during pregnancy who were successfully treated by mechanical clot retrieval using the Penumbra system 28 (Penumbra Inc., Alameda, California, USA). To the best of our knowledge, these are the only case reports on the use of the Penumbra device in pregnant patients with acute ischemic stroke.
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James CD, Fontan CT, Otoa R, Das D, Prabhakar AT, Wang X, Bristol ML, Morgan IM. Human Papillomavirus 16 E6 and E7 Synergistically Repress Innate Immune Gene Transcription. mSphere 2020; 5:e00828-19. [PMID: 31915229 PMCID: PMC6952203 DOI: 10.1128/msphere.00828-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 12/12/2019] [Indexed: 11/22/2022] Open
Abstract
Human papillomaviruses (HPV) are causative agents in 5% of all cancers, including the majority of anogenital and oropharyngeal cancers. Downregulation of innate immune genes (IIGs) by HPV to promote the viral life cycle is well documented; E6 and E7 are known repressors of these genes. More recently, we demonstrated that E2 could also repress IIGs. These studies have been carried out in cells overexpressing the viral proteins, and to further investigate the role of individual viral proteins in this repression, we introduced stop codons into E6 and/or E7 in the entire HPV16 genome and generated N/Tert-1 cells stably maintaining the HPV16 genomes. We demonstrate that E6 or E7 individually is not sufficient to repress IIG expression in the context of the entire HPV16 genome; both are required for a synergistic repression. The DNA damage response (DDR) is activated by HPV16 irrespective of E6 and E7 expression, presumably due to viral replication; E1 is a known activator of the DDR. In addition, replication stress was apparent in HPV16-positive cells lacking E6 and E7, manifested by attenuated cellular growth and activation of replication stress genes. These studies led us to the following model. Viral replication per se can activate the DDR following infection, and this activation is a known inducer of IIG expression, which may induce cellular senescence. To combat this, E6 and E7 synergistically combine to manipulate the DDR and actively repress innate immune gene expression promoting cellular growth; neither protein by itself is able to do this.IMPORTANCE The role of human papillomavirus 16 (HPV16) in human cancers is well established; however, to date there are no antiviral therapeutics that are available for combatting these cancers. To identify such targets, we must enhance the understanding of the viral life cycle. Innate immune genes (IIGs) are repressed by HPV16, and we have reported that this repression persists through to cancer. Reversal of this repression would boost the immune response to HPV16-positive tumors, an area that is becoming more important given the advances in immunotherapy. This report demonstrates that E6 and E7 synergistically repress IIG expression in the context of the entire HPV16 genome. Removal of either protein activates the expression of IIGs by HPV16. Therefore, gaining a precise understanding of how the viral oncogenes repress IIG expression represents an opportunity to reverse this repression and boost the immune response to HPV16 infections for therapeutic gain.
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Research Support, N.I.H., Extramural |
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Zimmerman MC, Prabhakar A, Chokshi BV, Budhwani N, Berndt H. The acoustic properties of normal and imbedded bovine bone as measured by acoustic microscopy. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1994; 28:931-8. [PMID: 7983091 DOI: 10.1002/jbm.820280812] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The acoustic impedance of bovine femoral cortical bone was measured with a scanning acoustic microscope used in the reflection mode. The bone was measured in the unimbedded state and after plastic imbedding. The acoustic impedance of the unimbedded specimens was also measured with a standard transmission ultrasonic technique. For the unimbedded bovine specimens there was a good correlation between the bulk transmission impedance and the reflection surface impedance (r2 = 0.976) and the values were 9.32 and 9.29 MRayls, respectively. Plastic imbedding produced a consistent and statistically significant increase in the acoustic impedance of the bone (9.71 MRayls). This experiment verified the use of acoustic microscopy as a quantitative materials analysis technique and it demonstrated the potential for material property analysis of imbedded bone.
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Singh B, Chandan BK, Prabhakar A, Taneja SC, Singh J, Qazi GN. Chemistry and hepatoprotective activity of an active fraction from Barleria prionitis Linn. in experimental animals. Phytother Res 2005; 19:391-404. [PMID: 16106393 DOI: 10.1002/ptr.1509] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Iridoid enriched fraction IF from the ethanol-water extract of aerial parts (leaves and stems) of Barleria prionitis Linn. was evaluated for hepatoprotective activity in various acute and chronic animal test models of hepatotoxicity. It afforded significant hepatoprotection against carbon tetrachloride, galactosamine and paracetamol induced hepatotoxicity. Silymarin, was used as reference hepatoprotective. In the safety evaluation study the oral LD50 was found to be more than 3000 mg/kg, with no signs of abnormalities or any mortality observed for 15 days period under observation after single dose of drug administration whereas intraperitoneal LD50 was found to be 2530 mg/kg+/-87 mg/kg. SE (n=10) in mice. The studies revealed significant and concentration dependent hepatoprotective potential of 'IF' as it reversed the majority of the altered hepatic parameters in experimental liver damage in rodents.
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Chrispal A, Boorugu H, Prabhakar AT, Moses V. Amikacin-induced type 5 Bartter-like syndrome with severe hypocalcemia. J Postgrad Med 2010; 55:208-10. [PMID: 19884751 DOI: 10.4103/0022-3859.57407] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Aminoglycoside-induced renal toxicity is well known and may manifest with nonoliguric renal failure or renal tubular dysfunction. Aminoglycoside-induced renal tubular dysfunction could result in diffuse damage or manifest as a Fanconi-like syndrome, Bartter-like syndrome, or distal renal tubular acidosis. We discuss a patient who developed severe renal tubular dysfunction secondary to short-term therapy with Amikacin, resulting in refractory hypokalemia, hypocalcemia, hypomagnesemia, metabolic alkalosis, and polyuria. This constellation of biochemical abnormalities mimic Type 5 Bartter's syndrome, where there is activating mutation of the calcium sensing receptor in the thick ascending loop of Henle and the distal tubule. In this case this activation of the calcium sensing receptor was triggered by amikacin. This phenomenon has been described with gentamicin though never with amikacin. Recovery of the tubular dysfunction took 15 days following cessation of the offending drug, Amikacin.
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Ramesh C, Ravindranath N, Das B, Prabhakar A, Bharatam J, Ravikumar K, Kashinatham A, McMorris TC. Pseudoguaianolides from the flowers of Parthenium hysterophorus. PHYTOCHEMISTRY 2003; 64:841-844. [PMID: 14559278 DOI: 10.1016/s0031-9422(03)00425-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Chemical investigation on the flowers of Parthenium hysterophorus has resulted in the isolation of four new pseudoguaianolides, hysterones A-D along with the known compounds, parthenin, coronopilin, 2beta-hydroxycoronopilin and tetraneurin-A. The structures of the new compounds were established by interpretation of their spectral (1D and 2D NMR) data. The X-ray crystallographic analysis of hysterones A and C was also carried out.
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Bizzarri MF, Prabhakar A, Bishop AH. Multiple-locus sequence typing analysis of Bacillus thuringiensis recovered from the phylloplane of clover (Trifolium hybridum) in vegetative form. MICROBIAL ECOLOGY 2008; 55:619-25. [PMID: 17682816 DOI: 10.1007/s00248-007-9305-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 06/18/2007] [Accepted: 07/15/2007] [Indexed: 05/16/2023]
Abstract
Abstract The chromosomal genotype, as judged by multi locus sequence typing, and the episomal genotype, as judged by plasmid profile and cry gene content, were analyzed for a collection of strains of Bacillus thuringiensis. These had been recovered in vegetative form over a period of several months from the leaves of a small plot of clover (Trifolium hybridum). A clonal population structure was indicated, although greater variation in sequence types (STs) was discovered than in previous collections of B. cereus/B. thuringiensis. Isolates taken at the same time had quite different genotypes, whereas those of identical genotypes were recovered at different times. The profiles of plasmid content and cry genes generally bore no relation to each other nor to the STs. Evidently, although relatively little recombination was occurring in the seven chromosomal genes analyzed, a great deal of conjugal transfer, and perhaps recombination, was occurring involving plasmids. A clinical diarrheal isolate of B. cereus and the commercial biopesticide strain HD-1 of B. thuringiensis, both included as out-groups, were found to have very similar STs. This further emphasizes the role of episomal elements in the characteristics and differentiation of these two species.
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Tharmalingam J, Prabhakar AT, Gangadaran P, Dorny P, Vercruysse J, Geldhof P, Rajshekhar V, Alexander M, Oommen A. Host Th1/Th2 immune response to Taenia solium cyst antigens in relation to cyst burden of neurocysticercosis. Parasite Immunol 2016; 38:628-634. [PMID: 27493081 DOI: 10.1111/pim.12351] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 08/02/2016] [Indexed: 01/02/2023]
Abstract
Neurocysticercosis (NCC), Taenia solium larval infection of the brain, is an important cause of acquired seizures in endemic countries, which relate to number, location and degenerating cysts in the brain. Multicyst infections are common in endemic countries although single-cyst infection prevails in India. Single-cyst infections in an endemic country suggest a role for host immunity limiting the infection. This study examined ex vivo CD4(+) T cells and in vitro Th1 and Th2 cytokine responses to T. solium cyst antigens of peripheral blood mononuclear cells of healthy subjects from endemic and nonendemic regions and of single- and multicyst-infected patients for association with cyst burden of NCC. T. solium cyst antigens elicited a Th1 cytokine response in healthy subjects of T. solium-endemic and T. solium-non-endemic regions and those with single-cyst infections and a Th2 cytokine response from subjects with multicyst neurocysticercosis. Multicyst neurocysticercosis subjects also exhibited low levels of effector memory CD4(+) T cells. Th1 cytokine response of T. solium exposure and low infectious loads may aid in limiting cyst number. Th2 cytokines and low effector T cells may enable multiple-cyst infections to establish and persist.
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Mohan A, Gupta P, Nair AP, Prabhakar A, Saiyed T. A microfluidic flow analyzer with integrated lensed optical fibers. BIOMICROFLUIDICS 2020; 14:054104. [PMID: 33062113 PMCID: PMC7532020 DOI: 10.1063/5.0013250] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
Rapid optical interrogation of flowing cells or particles is a powerful tool in the field of biomedical diagnostics. Determination of size and composition of fast-flowing cells, with diameters in the range of 2- 15 μ m , often require complex open-space optics and expensive high-speed cameras. In this work, a method to overcome these challenges by using a hydrodynamic flow-based microfluidic platform coupled with on-chip integrated fiber optics is reported. The lab-scale portable device developed uses a combination of on-chip lensed and non-lensed optical fibers for precision illumination. The narrow light beam produced by the lensed fiber ( f = 150 μ m ) enables precise optical analysis with high sensitivity. A planar arrangement of optical fibers at various angles facilitates multi-parametric analysis from a single point of interrogation. As proof of concept, the laboratory-scale portable bench-top prototype is used to measure fluorescence signals from CD4 immunostained cells and human blood samples. The performance of microfluidic flow analyzer is also compared to the conventional Guava® easyCyte 8HT flow cytometer.
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Aaron S, Lakshmanan J, Sudarsanam TD, Benjamin K, Durairaj J, Mathew V, Sivadasan A, Prabhakar AT, Keshava SKN, Mannam PR, Kirubakaran P, Muliyil J, Alexander M. Cerebral Venous Thrombosis, Seasonal Trends, and Climatic Influence: A Region-SpecificStudy. Ann Indian Acad Neurol 2019; 23:522-527. [PMID: 33223671 PMCID: PMC7657288 DOI: 10.4103/aian.aian_409_19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 08/28/2019] [Accepted: 09/05/2019] [Indexed: 11/18/2022] Open
Abstract
Background and Purpose: Studies looking at seasonal variation on cerebral venous thrombosis (CVT) are few with conflicting conclusions. In this region-specific study, we looked for climatic influence and seasonal trends on the incidence of CVT. Methods: Imaging proven adult CVT cases treated over a period of 18 years from a specific geographical location with similar seasons and climatic conditions were studied. Metrological parameters prepared using 30 years of data was used. Quantum geographical information system (QGIS software) and SPSS v 22 were used for patient plotting and analysis. Results: Total of 970 cases were studied. The incidence was significantly higher in summer 411 (42.3%) compared with autumn 317 (32.7%) and winter 242 (25.05); P = 0.038. This trend was consistent across all the 18 years in time series analysis. Mean age was 33.5 years (range 18–88 years). A significant majority 673 (69.4%) were below 40 years of age; P = 0.012. Females constituted 394 (40.6%) of cases. Postpartum CVT cases constituted 237 (30%). Interaction analysis showed younger age (<40 years) were more vulnerable for CVT in summer; P = 0.009. There was no seasonal influence on postpartum CVT. Apart for a weak positive correlation between rain fall (r = 0.18, P < 0.01); humidity and cloud cover was not influencing the incidence. Conclusions: Higher ambient temperatures were consistently associated with higher incidence of CVT. This is the largest region-specific study on CVT in the world. These results may be applicable to other regions with similar climatic conditions.
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Prabhakar AT, James CD, Das D, Otoa R, Day M, Burgner J, Fontan CT, Wang X, Glass SH, Wieland A, Donaldson MM, Bristol ML, Li R, Oliver AW, Pearl LH, Smith BO, Morgan IM. CK2 Phosphorylation of Human Papillomavirus 16 E2 on Serine 23 Promotes Interaction with TopBP1 and Is Critical for E2 Interaction with Mitotic Chromatin and the Viral Life Cycle. mBio 2021; 12:e0116321. [PMID: 34544280 PMCID: PMC8546539 DOI: 10.1128/mbio.01163-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 08/19/2021] [Indexed: 01/05/2023] Open
Abstract
During the human papillomavirus 16 (HPV16) life cycle, the E2 protein interacts with host factors to regulate viral transcription, replication, and genome segregation/retention. Our understanding of host partner proteins and their roles in E2 functions remains incomplete. Here we demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 in vitro and in vivo and that E2 is phosphorylated on this residue during the HPV16 life cycle. We investigated the consequences of mutating serine 23 on E2 functions. E2-S23A (E2 with serine 23 mutated to alanine) activates and represses transcription identically to E2-WT (wild-type E2), and E2-S23A is as efficient as E2-WT in transient replication assays. However, E2-S23A has compromised interaction with mitotic chromatin compared with E2-WT. In E2-WT cells, both E2 and TopBP1 levels increase during mitosis compared with vector control cells. In E2-S23A cells, neither E2 nor TopBP1 levels increase during mitosis. Introduction of the S23A mutation into the HPV16 genome resulted in delayed immortalization of human foreskin keratinocytes (HFK) and higher episomal viral genome copy number in resulting established HFK. Remarkably, S23A cells had a disrupted viral life cycle in organotypic raft cultures, with a loss of E2 expression and a failure of viral replication. Overall, our results demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 and that this interaction is critical for the viral life cycle. IMPORTANCE Human papillomaviruses are causative agents in around 5% of all cancers, with no specific antiviral therapeutics available for treating infections or resultant cancers. In this report, we demonstrate that phosphorylation of HPV16 E2 by CK2 promotes formation of a complex with the cellular protein TopBP1 in vitro and in vivo. This complex results in stabilization of E2 during mitosis. We demonstrate that CK2 phosphorylates E2 on serine 23 in vivo and that CK2 inhibitors disrupt the E2-TopBP1 complex. Mutation of E2 serine 23 to alanine disrupts the HPV16 life cycle, hindering immortalization and disrupting the viral life cycle, demonstrating a critical function for this residue.
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Research Support, N.I.H., Extramural |
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Vanjare HA, Selvi BT, Karuppusami R, Manesh A, Gunasekaran K, Prabhakar AT, Mannam P, Jasper A. Clinical and Radiologic Findings of Acute Necrotizing Encephalopathy in Young Adults. AJNR Am J Neuroradiol 2020; 41:2250-2254. [PMID: 33122207 DOI: 10.3174/ajnr.a6803] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 07/15/2020] [Indexed: 12/23/2022]
Abstract
Acute necrotizing encephalopathy after an acute febrile illness, although initially described exclusively in the pediatric age group, has been recently shown to have an adult onset as well. In this study, we describe 10 patients (16 years of age or older) with acute necrotizing encephalopathy. In our study, bilateral thalamic involvement with the trilaminar pattern of diffusion restriction on MR imaging was the predominant finding seen in all of the patients reviewed. Ancillary findings of cerebral white matter, brain stem, and cerebellum involvement with sparing of the basal ganglia were also noted. A poorer outcome was observed in patients with a higher degree of thalamic involvement. The cause of an underlying infection was identified in 4 patients (dengue in 3 and influenza in 1). Overall, a sizeable portion of young adults with acute necrotizing encephalopathy have shown a poorer outcome, with dengue being an important underlying trigger in an endemic region.
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Prabhakar A, Bishop AH. Effect of Bacillus thuringiensis naturally colonising Brassica campestris var. chinensis leaves on neonate larvae of Pieris brassicae. J Invertebr Pathol 2009; 100:193-4. [PMID: 19232351 DOI: 10.1016/j.jip.2009.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Revised: 02/05/2009] [Accepted: 02/05/2009] [Indexed: 11/27/2022]
Abstract
The feeding of neonate larvae of Pieris brassicae (Order Lepidoptera) on leaves of brassica plants that had been colonised by Bacillus thuringiensis resulted in the death of 35% of the population within 72h. The bacteria multiplied in the cadavers, resulting in an increase of about 50-fold compared to the living insects. Surviving insects showed no ill effects during the time of the study. There was negligible multiplication of B. thuringiensis in the frass.
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Prabhakar A, Bishop AH. Invertebrate pathogenicity and toxin-producing potential of strains of Bacillus thuringiensis endemic to Antarctica. J Invertebr Pathol 2011; 107:132-8. [PMID: 21457716 DOI: 10.1016/j.jip.2011.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Revised: 03/07/2011] [Accepted: 03/21/2011] [Indexed: 10/18/2022]
Abstract
Several strains of Bacillus thuringiensis were previously isolated from soil in Antarctica and appeared to have physiological adaptations to this cold, nutrient-poor environment. In spite of this they could produce abnormally large, parasporal crystals under laboratory conditions. Here, they have been further characterised for toxin genes and invertebrate pathogenicity. All of the strains were positive in PCR assays for the cry1Aa and cry2 genes. This was confirmed by sequence analysis and the parasporal crystals of all strains contained polypeptides of about 130kDa. This potential for lepidopteran toxicity was borne out in bioassays of purified δ-endotoxins against larvae of Pieris brassicae: the LD(50) values of B2408 (288μg) were comparable to that of the reference strain, HD-12 (201μg). There was no activity against the nematode Caenorhabditis elegans in spite of the fact that all strains appeared to possess the cry6 gene. PCR screening for genes encoding other nematode-toxic classes of toxins (Cry5, 4 and 21) was negative. B. thuringiensis has never previously been shown to be toxic to Collembola (springtails) but the purified δ-endotoxins of one of the Antarctic strains showed some activity against Folsomia candida and Seira domestica (224μg and 238μg, respectively). It seems unlikely that the level of toxicity demonstrated against springtails would support a pathogenic life-style in nature. All of the strains were positive for genes encoding Bacillus cereus-type enterotoxins. In the absence of higher insects and mammals the ecological value of retaining the toxic capability demonstrated here is uncertain.
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Diener HC, Akagi T, Durongpisitkul K, Thomson VS, Prabhakar AT, Sharpe R, Albers B, Lewalter T, Oki K, Sharma VK. Closure of the patent foramen ovale in patients with embolic stroke of undetermined source: A clinical expert opinion and consensus statement for the Asian-Pacific region. Int J Stroke 2020; 15:937-944. [PMID: 32677579 DOI: 10.1177/1747493020941658] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2024]
Abstract
Recently published long-term data from randomized controlled trials have provided evidence for the prevention of recurrent embolic stroke of undetermined source by percutaneous closure of the patent foramen ovale. However, most data were obtained from Caucasian populations and evidence on patent foramen ovale closure in Asian-Pacific patients is limited. The relative paucity in clinical data from this population, as well as the fact that Asian-Pacific patients may have higher bleeding risks than Caucasians, complicates clinical decision-making. This document, resulting from a consensus meeting of Asian-Pacific clinical experts, states the consensus among these experts about how to treat Asian-Pacific patients who had an embolic stroke of undetermined source and have a patent foramen ovale, based on currently available evidence and expert opinions. In addition, uncertainties and the need for clinical data regarding patent foramen ovale closure for prevention of recurrent embolic stroke of undetermined source in general, and specifically for Asian-Pacific patients, are identified.
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Aaron S, Mani S, Prabhakar AT, Karthik K, Patil AKB, Babu PS, Alexander M. Stuck with a drowsy patient, evoke the Percheron. Neurol India 2015; 63:542-7. [PMID: 26238889 DOI: 10.4103/0028-3886.162045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Strokes caused by normal variants of the cerebral circulation can be difficult to diagnose, hence a high index of suspicion is needed. This case series discusses the clinical and radiological aspects of one such stroke caused by occlusion of the artery of Percheron (AOP). MATERIALS AND METHODS Computerized discharge summaries, outpatient records and imaging from picture archiving and communication system (PACS, GE), of patients with AOP infarction over a period of 12-years (2002-2014) were identified and their clinical and radiological features analyzed. RESULTS Of 3589 strokes (both ischemic and hemorrhagic), 17 (0.47%) were due to AOP infarction. Their mean age was 50 years (range: 31-72 years). Disorders of consciousness (94%) were the most common presenting symptoms followed by gaze (53%) and memory impairment (24%). At follow-up, 2/17 (12%) patients developed extrapyramidal features. All patients had bilateral paramedian thalamic infarcts on magnetic resonance imaging (MRI). Associated anterior thalamic (5/17; 30%) and mid brain (10/17; 59%) infarcts were also seen. CT scan done in 11/17 patients prior to the MRI picked up only 6/11 (55%) of these infarcts. The most common etiological factors detected using the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria were cardio embolic (8/17; 47%) followed by small vessel occlusion (7/17; 41%). Mortality occurred in 2/17 (12%) patients. At 6 months, a modified Rankin score of 2 or less was seen in 8/17 (47%) patients. CONCLUSIONS Artery of Percheron infarcts should be considered in the differential diagnosis of patients presenting with sudden alterations in consciousness. MRI should be the investigation of choice. An embolic etiology should be actively looked for.
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Fontan CT, Prabhakar AT, Wang X, Karimi E, Bristol ML, James CD, Morgan IM. Human papillomavirus 16 E2 blocks cellular senescence in response to activation of the DNA damage response. Virology 2022; 575:54-62. [PMID: 36058086 PMCID: PMC10715573 DOI: 10.1016/j.virol.2022.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 11/21/2022]
Abstract
Following infection by HPV16, the viral proteins E1 and E2 induce viral genome replication in association with host factors. Here we demonstrate that E2 also plays a role in promoting short-term cellular proliferation in the presence of an active DDR. Cisplatin treatment of E2 expressing cells results in short-term proliferation likely due to a block of cellular senescence and apoptosis. However, long-term growth of E2 expressing cells following cisplatin treatment is attenuated due to an accumulation of DNA damage. We discuss a possible role for this E2 function during the viral life cycle. It is also notable that E2 expressing HPV16 positive cancers have a better clinical outcome than non-E2 expressing tumors. While there are a variety of reasons for the better outcome of patients with E2 expressing tumors, this report suggests that E2 regulation of the DNA damage response may be a contributory factor.
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Alexander M, Sivadasan A, Aaron S, Mathew V, Nair S, Muthusamy K, Prabhakar AT, Benjamin R, Shaikh A, Rynjah G. Comorbidities and long-term outcomes in a cohort with myasthenic crisis: Experiences from a tertiary care center. Ann Indian Acad Neurol 2019; 22:464-471. [PMID: 31736571 PMCID: PMC6839309 DOI: 10.4103/aian.aian_197_19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 06/26/2019] [Accepted: 06/30/2019] [Indexed: 11/05/2022] Open
Abstract
Introduction: There is scarce literature regarding the clinical course, comorbidities and long-term outcomes after myasthenic crisis (MC). The natural history of myasthenia gravis (MG) in this subset remains uncertain. Methods: The study included a cohort admitted with MC (2007–2017) in a tertiary care hospital. The comorbidities, outcomes after discharge, and prognostic factors were analyzed. Results: Sixty-two patients (89 episodes of MC) were included. Demographic data was comparable between the early- (<50 years) and late-onset (≥50 years) groups. Comorbidities included stress cardiomyopathy (14.5%), arrhythmias (6.4%), neuropathy (17.7%), pancytopenia (12.9%), encephalopathy (11.2%), neuromyotonia (4.8%), myelopathy (3.2%), and myositis (3.2%). Pulmonary embolism (P < 0.008), dysautonomia (P < 0.002), sepsis (P < 0.008), neuropathy (P < 0.002), and phrenic dysfunction (P < 0.016) were associated with prolonged ventilation. Majority of the patients (42, 67.7%) had a favorable outcome (disease status) as defined by remission/minimal manifestations at the time of last follow-up (median 36 months, IQR 15–66). Persistent bulbar weakness (P < 0.001), neuropsychiatric illness (P < 0.001), and comorbidities (P < 0.017) were associated with refractory MG. Eighteen patients (29%) had recurrent crisis. Eleven patients succumbed in the cohort. The main predictors of mortality were tumor progression (P < 0.001) and cardiac illness (P < 0.004). Discussion: A comprehensive treatment approach in MC will translate to good short- and long-term outcomes. The main cornerstones of therapy will include (1) Identification of refractory MG with the implementation of phenotype-based therapy; (2) Addressing comorbidities including cardiac autonomic neuropathy, bulbar weakness, phrenic dysfunction; and (3) Meticulous tumor surveillance.
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Patil AKB, Prabhakar AT, Sivadasan A, Alexander M, Chacko G. An unusual case of inflammatory necrotizing myopathy and neuropathy with pipestem capillaries. Neurol India 2015; 63:72-6. [PMID: 25751473 DOI: 10.4103/0028-3886.152642] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Necrotizing myopathy with pipestem capillaries is a form of chronic inflammatory myopathy, with histopathology showing necrotizing myopathy, minimal cellular infiltration, and microangiopathy. A 30-year-old female presented with progressive limb weakness of 6 months, with skin pigmentation and Raynaud's phenomenon. Serum creatine phosphokinase was 3990 u/L. Muscle biopsy showed necrotic fibers, focal sparse perivascular inflammation/perifascicular atrophy, endomysial/epimysial vessel wall thickening with luminal narrowing. The features were of inflammatory necrotizing myopathy and neuropathy with pipestem capillaries/microangiopathy. She was pulsed with intravenous immunoglobulin, methylprednisolone, and cyclophosphamide and showed a good improvement. In the absence of widespread inflammatory response and classical histopathology findings, it is important to diagnose this condition as it shows a good response to aggressive and prolonged immunotherapy.
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Fontan CT, James CD, Prabhakar AT, Bristol ML, Otoa R, Wang X, Karimi E, Rajagopalan P, Basu D, Morgan IM. A Critical Role for p53 during the HPV16 Life Cycle. Microbiol Spectr 2022; 10:e0068122. [PMID: 35608342 PMCID: PMC9241828 DOI: 10.1128/spectrum.00681-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 04/22/2022] [Indexed: 12/15/2022] Open
Abstract
Human papillomaviruses (HPV) are causative agents in ano-genital and oral cancers; HPV16 is the most prevalent type detected in human cancers. The HPV16 E6 protein targets p53 for proteasomal degradation to facilitate proliferation of the HPV16 infected cell. However, in HPV16 immortalized cells E6 is predominantly spliced (E6*) and unable to degrade p53. Here, we demonstrate that human foreskin keratinocytes immortalized by HPV16 (HFK+HPV16), and HPV16 positive oropharyngeal cancers, retain significant expression of p53. In addition, p53 levels increase in HPV16+ head and neck cancer cell lines following treatment with cisplatin. Introduction of full-length E6 into HFK+HPV16 resulted in attenuation of cellular growth (in hTERT immortalized HFK, E6 expression promoted enhanced proliferation). An understudied interaction is that between E2 and p53 and we investigated whether this was important for the viral life cycle. We generated mutant genomes with E2 unable to interact with p53 resulting in profound phenotypes in primary HFK. The mutant induced hyper-proliferation, but an ultimate arrest of cell growth; β-galactosidase staining demonstrated increased senescence, and COMET assays showed increased DNA damage compared with HFK+HPV16 wild-type cells. There was failure of the viral life cycle in organotypic rafts with the mutant HFK resulting in premature differentiation and reduced proliferation. The results demonstrate that p53 expression is critical during the HPV16 life cycle, and that this may be due to a functional interaction between E2 and p53. Disruption of this interaction has antiviral potential. IMPORTANCE Human papillomaviruses are causative agents in around 5% of all cancers. There are currently no antivirals available to combat these infections and cancers, therefore it remains a priority to enhance our understanding of the HPV life cycle. Here, we demonstrate that an interaction between the viral replication/transcription/segregation factor E2 and the tumor suppressor p53 is critical for the HPV16 life cycle. HPV16 immortalized cells retain significant expression of p53, and the critical role for the E2-p53 interaction demonstrates why this is the case. If the E2-p53 interaction is disrupted then HPV16 immortalized cells fail to proliferate, have enhanced DNA damage and senescence, and there is premature differentiation during the viral life cycle. Results suggest that targeting the E2-p53 interaction would have therapeutic benefits, potentially attenuating the spread of HPV16.
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Sooragonda BG, Agarwal S, Benjamin RN, Prabhakar AT, Sivadasan A, Kapoor N, Cherian KE, Jebasingh FK, Aaron S, Thomas N, Mathew V, Asha HS, Paul TV. Bone Mineral Density and Body Composition in Males with Motor Neuron Disease: A Study from Teaching Hospital in Southern Part of India. Ann Indian Acad Neurol 2020; 24:211-216. [PMID: 34220065 PMCID: PMC8232495 DOI: 10.4103/aian.aian_293_20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 04/26/2020] [Accepted: 05/17/2020] [Indexed: 11/04/2022] Open
Abstract
Background Osteoporosis and sarcopenia are important aspects of motor neuron disease (MND). Individuals with amyotrophic lateral sclerosis (MND-ALS) have an increased risk of falls and fractures. Currently, the standard of care does not involve a routine assessment of bone mineral density (BMD) and body composition in these patients. We aimed to assess BMD, bone mineral parameters and body composition in men with MND and compared them with healthy controls. Methods Consecutive males between 50 and 80 years of age diagnosed as MND-ALS by revised El Escorial criteria and able to walk unassisted attending Neurology outpatient clinic were recruited into the study. Age, gender and body mass index (BMI) matched healthy controls were recruited from the local community. BMD and body composition were assessed by dual-energy x-ray absorptiometry (DXA). Bone mineral parameters and bone turnover markers (BTMs) were also assessed in them. Results A total of 30 subjects with MND-ALS and 33 controls were recruited. The mean age (years) was 59.2 in cases and 61.2 in controls. The mean BMD (g/cm2) between the two groups was similar; however, BTMs were significantly higher in the MND group (P < 0.05). Subjects with MND-ALS had significantly lower mean appendicular lean mass (ALM) (19.9 versus 22.4 kg; P = 0.007) and ALM corrected for BMI than the healthy control group (0.858 versus 0.934 kg/kg/m2; P = 0.034). Sarcopenic obesity (Percentage fat mass >27% + ALM/BMI <0.786 kg/kg/m2) was more prevalent in MND-ALS compared to controls (44.5% versus 16.7%; P = 0.03). Conclusion Although BMD was not significantly different between subjects with MND-ALS and healthy controls, BTMs were significantly higher in the MND group indicating a high bone turnover state. Sarcopenia and sarcopenic obesity were also more in MND-ALS group than controls. Routine assessment for bone health parameters and body composition indices may be included in management of the patients with MND.
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Alexander M, Prabhakar AT, Aaron S, Thomas M, Mathew V, Patil AK. Utility of neurophysiological criteria in Guillain Barre΄ syndrome: subtype spectrum from a tertiary referral hospital in India. Neurol India 2011; 59:722-6. [PMID: 22019658 DOI: 10.4103/0028-3886.86548] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND The Guillain Barre' syndrome (GBS) is a heterogeneous disease with various subtypes, the prevalence of which would depend on the geographic region. Recognition of these subtypes is of clinical importance since each subtype has an independent pathogenesis and different type of pathology and prognosis. OBJECTIVES To study the various subtypes of GBS using the various published electrophysiological criteria. DESIGN Retrospective descriptive study. MATERIALS AND METHODS In a tertiary care hospital setting, the study compared the various published criteria for demyelination in GBS. The charts of 115 consecutive patients referred for electrodiagnostic evaluation to the Electromyography laboratory between July 2000 and June 2006 were reviewed. RESULTS Of the 115 patients, 51 (44.4%) patients had axonal forms of GBS and 44 (38.2%) patients had acute inflammatory demyelinating polyradiculoneuropathy (AIDP). Applying the various published criteria, the number of patients categorized under the AIDP subtype ranged between 23.4% and 67.2%. CONCLUSION In this study 44% patients had axonal forms of the disease, 38.2% patients had AIDP subtype and 17% remained unclassified. The most sensitive criteria to identify AIDP were the criteria proposed by Albers and colleagues and the Dutch group.
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Arora S, Srivastava MVP, Singh MB, Goyal V, Häberle J, Gupta N, Prabhakar A, Aggarwal B, Agarwal A, Vishnu VY. Adult onset type II citrullinemia--a great masquerader. QJM 2020; 113:49-51. [PMID: 31532496 DOI: 10.1093/qjmed/hcz238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Indexed: 12/30/2022] Open
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