751
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MacKenzie-Graham A, Tiwari-Woodruff SK, Sharma G, Aguilar C, Vo KT, Strickland LV, Morales L, Fubara B, Martin M, Jacobs RE, Johnson GA, Toga AW, Voskuhl RR. Purkinje cell loss in experimental autoimmune encephalomyelitis. Neuroimage 2009; 48:637-51. [PMID: 19589388 DOI: 10.1016/j.neuroimage.2009.06.073] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 06/20/2009] [Accepted: 06/29/2009] [Indexed: 12/21/2022] Open
Abstract
Gray matter atrophy observed by brain MRI is an important correlate to clinical disability and disease duration in multiple sclerosis. The objective of this study was to link brain atrophy visualized by neuroimaging to its underlying neuropathology using the MS model, experimental autoimmune encephalomyelitis (EAE). Volumetric changes in brains of EAE mice, as well as matched healthy normal controls, were quantified by collecting post-mortem high-resolution T2-weighted magnetic resonance microscopy and actively stained magnetic resonance histology images. Anatomical delineations demonstrated a significant decrease in the volume of the whole cerebellum, cerebellar cortex, and molecular layer of the cerebellar cortex in EAE as compared to normal controls. The pro-apoptotic marker caspase-3 was detected in Purkinje cells and a significant decrease in Purkinje cell number was found in EAE. Cross modality and temporal correlations revealed a significant association between Purkinje cell loss on neuropathology and atrophy of the molecular layer of the cerebellar cortex by neuroimaging. These results demonstrate the power of using combined population atlasing and neuropathology approaches to discern novel insights underlying gray matter atrophy in animal models of neurodegenerative disease.
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752
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Nagpal A, Pai KM, Sharma G. Palatal and labially impacted maxillary canine-associated dental anomalies: a comparative study. J Contemp Dent Pract 2009; 10:67-74. [PMID: 19575056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
AIM To determine the association of impacted maxillary canines with other developmental dental anomalies and compare them with a control population and to compare palatally and labially impacted canine associated anomalies. METHODS AND MATERIALS Ninety non-syndromic orthodontic patients from a south Indian population, with either labial or palatal impactions of one or both maxillary canine teeth, were selected for the study group. A group of 250 patients who had normally erupted maxillary canines were selected as controls. Clinical findings and panoramic radiographs were used to identify dental anomalies. RESULTS Prevalence of premolar rotation was found to be 80% in the study group followed by canine rotation (20%), taurodontism (26.6%), infraocclusion of premolars (25.5%), impacted mandibular canine (11.1%), and peg lateral (7.7%). Forty-nine (54.4%) palatally impacted, 37 (41.1%) labially impacted, and 4 (4.4%) centrally impacted canines were also observed. Of the 250 subjects in the control group 78.8% presented with premolar rotation. Maxillary canine transmigration, infraocclusion of premolars, anomalies of maxillary lateral incisors, and taurodontism showed significant associations with palatally impacted canines (P<0.05). CONCLUSION The present study illustrates a significant association of anomalous maxillary lateral, anomalous mandibular canine, taurodontism, infra occlusion of premolar, over retained deciduous molar, and maxillary canine transmigration with ectopically placed canines. These associations suggest these conditions may share a common genetic origin and existence of these anomalies can anticipate maxillary canine impaction which can help in cautious observation and early treatment for maxillary canine impaction. CLINICAL SIGNIFICANCE Anomalous lateral incisors can serve as a predictor for palatal maxillary canine impaction. These anomalies could serve as an easily recognized, early warning sign for the monitoring of the canine position and timely early referral in appropriate cases.
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753
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Su FH, Blanchard F, Sharma G, Razzari L, Ayesheshim A, Cocker TL, Titova LV, Ozaki T, Kieffer JC, Morandotti R, Reid M, Hegmann FA. Terahertz pulse induced intervalley scattering in photoexcited GaAs. OPTICS EXPRESS 2009; 17:9620-9629. [PMID: 19506611 DOI: 10.1364/oe.17.009620] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Nonlinear transient absorption bleaching of intense few-cycle terahertz (THz) pulses is observed in photoexcited GaAs using opticalpump--THz-probe techniques. A simple model of the electron transport dynamics shows that the observed nonlinear response is due to THz-electric- field-induced intervalley scattering over sub-picosecond time scales as well as an increase in the intravalley scattering rate attributed to carrier heating. Furthermore, the nonlinear nature of the THz pulse transmission at high peak fields leads to a measured terahertz conductivity in the photoexcited GaAs that deviates significantly from the Drude behavior observed at low THz fields, emphasizing the need to explore nonlinear THz pulse interactions with materials in the time domain.
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754
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Drabkin HA, Sharma G, Costa LJ, Korch C, Gemmill RM. Synergistic growth inhibition of RCC and NSCLC cell lines by sorafenib plus vorinostat and induction of angiogenic genes by ER stress. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e16114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e16114 Sorafenib, vorinostat and the combination were examined in 34 RCC and NSCLC cell lines. In growth assays, sorafenib at 8 μM resulted in synergy with multiple vorinostat doses, whereas no synergy was seen with lower doses. Changes in phospho-ERK and AKT were not predictive of growth inhibition, whereas frequent inhibition of cyclin D1 and upregulation of p21Waf1 was observed. To anticipate resistance mechanisms to the anti-angiogenic effects of sorafenib, we studied the expression of 13 angiogenic factors in 10 selected lines. At baseline, bFGF, VEGF and IL-8 were highly expressed in RCCs, whereas Gro-α, VEGF, and IL-8 predominated in NSCLCs. Multiple angiogenic factors were upregulated by sorafenib and vorinostat, especially VEGF, IL-6, CTGF, EDN1, PDGFβ, and IL-8. Importantly, sorafenib at 8 μM, but not lower doses, induced ER stress in these cell lines and thapsigargin or tunicamycin treatment recapitulated many, but not all, of the observed angiogenic gene responses to sorafenib. In fact, CHOP induction by sorafenib plus vorinostat was the only parameter, other than growth inhibition, that changed in a synergistic manner. In summary, sorafenib plus vorinostat potently inhibits the in vitro growth of RCC and NSCLC cell lines. Upregulation of multiple angiogenic genes, in part by an ER-stress mechanism, may contribute to acquired resistance in vivo. No significant financial relationships to disclose.
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755
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Harmanci AO, Sharma G, Mathews DH. Stochastic sampling of the RNA structural alignment space. Nucleic Acids Res 2009; 37:4063-75. [PMID: 19429694 PMCID: PMC2709569 DOI: 10.1093/nar/gkp276] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A novel method is presented for predicting the common secondary structures and alignment of two homologous RNA sequences by sampling the 'structural alignment' space, i.e. the joint space of their alignments and common secondary structures. The structural alignment space is sampled according to a pseudo-Boltzmann distribution based on a pseudo-free energy change that combines base pairing probabilities from a thermodynamic model and alignment probabilities from a hidden Markov model. By virtue of the implicit comparative analysis between the two sequences, the method offers an improvement over single sequence sampling of the Boltzmann ensemble. A cluster analysis shows that the samples obtained from joint sampling of the structural alignment space cluster more closely than samples generated by the single sequence method. On average, the representative (centroid) structure and alignment of the most populated cluster in the sample of structures and alignments generated by joint sampling are more accurate than single sequence sampling and alignment based on sequence alone, respectively. The 'best' centroid structure that is closest to the known structure among all the centroids is, on average, more accurate than structure predictions of other methods. Additionally, cluster analysis identifies, on average, a few clusters, whose centroids can be presented as alternative candidates. The source code for the proposed method can be downloaded at http://rna.urmc.rochester.edu.
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756
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Blanchard F, Sharma G, Ropagnol X, Razzari L, Morandotti R, Ozaki T. Improved terahertz two-color plasma sources pumped by high intensity laser beam. OPTICS EXPRESS 2009; 17:6044-6052. [PMID: 19365426 DOI: 10.1364/oe.17.006044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We investigate the intensity dependent spatial drift of two-color plasma based terahertz (THz) sources. A simple scheme that uses an off-axis parabolic mirror is presented to overcome this shifting. In addition, the THz energy and electric field measurements are related via the real time images of the THz spot size.
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757
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Sharma G, Mavroidis C, Rege K, Yarmush ML, Budil D. Computational Studies of a Protein-based Nanoactuator for Nanogripping Applications. Int J Rob Res 2009. [DOI: 10.1177/0278364908100278] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The design hypothesis, architectures, and computational modeling of a novel peptide-based nanoactuator are presented in this paper. We engineered the α-helical coiled-coil portion of the yeast transcriptional activator peptide called GCN4 to obtain an environmentally responsive nanoactuator. The dimeric coiled-coil peptide consists of two identical approximately 4.5 nm long and approximately 3 nm wide polypeptide chains. The actuation mechanism depends on the modification of electrostatic charges along the peptide by varying the pH of the solution resulting in the reversible movement of helices and, therefore, creating the motion of an actuator. Using molecular dynamics simulations we showed that pH changes led to a reversible opening of up to 1.5 nm which is approximately 150% of the initial separation of the nanoactuator. We also investigated the forces generated by the nanoactuator upon pH actuation, using a new method based on a modified steered molecular dynamics technique. Owing to its open and close motion resembling that of tweezers, the new nanoactuator can potentially be used as a nanogripper in various nanomanipulation tasks such as detection and removal of heavy metal ions during nanofabrication processes or as a molecular switch.
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758
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Abstract
Obesity is a worldwide epidemic and is known to increase the risk of cardiovascular disease, type 2 diabetes, and certain forms of cancer. In addition, obesity is now recognized as an important risk factor in the development of several respiratory diseases. Of these respiratory diseases, it has already been well established that obesity can lead to obstructive sleep apnea (OSA) and obesity-hypoventilation syndrome (OHS). More recent data suggest that the prevalence of wheezing and bronchial hyper-responsiveness, two symptoms often associated with asthma, are increased in overweight and obese individual. Indeed, epidemiological studies have reported that obesity is a risk factor for the development of asthma. Furthermore, a number of studies indicate that obesity is also associated with a higher risk of developing deep vein thrombi, pulmonary emboli, pulmonary hypertension, and pneumonia. Finally, weight reduction has been shown to be effective in improving the symptoms and severity of several respiratory diseases, including OSA and asthma. Thus, overweight and obese patients should be encouraged to lose weight to reduce their risk of developing respiratory diseases or improve the course of pre-existing conditions.
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759
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Sharma G, Sharma A. Congenital bladder diverticulum in a 28-year-old male: A rare cause of urinary retention. AFRICAN JOURNAL OF UROLOGY 2009. [DOI: 10.1007/s12301-009-0006-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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760
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Singh BR, Jyoti J, Chandra M, Babu N, Sharma G. Drug resistance patterns of Salmonella isolates of equine origin from India. J Infect Dev Ctries 2009; 3:141-7. [DOI: 10.3855/jidc.61] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Indexed: 10/31/2022] Open
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761
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van der Walle CF, Sharma G, Ravi Kumar MNV. Current approaches to stabilising and analysing proteins during microencapsulation in PLGA. Expert Opin Drug Deliv 2009; 6:177-86. [DOI: 10.1517/17425240802680169] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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762
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Altun HO, Orsdemir A, Sharma G, Bocko MF. Optimal spread spectrum watermark embedding via a multistep feasibility formulation. IEEE TRANSACTIONS ON IMAGE PROCESSING : A PUBLICATION OF THE IEEE SIGNAL PROCESSING SOCIETY 2009; 18:371-387. [PMID: 19131302 DOI: 10.1109/tip.2008.2008222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We consider optimal formulations of spread spectrum watermark embedding where the common requirements of watermarking, such as perceptual closeness of the watermarked image to the cover and detectability of the watermark in the presence of noise and compression, are posed as constraints while one metric pertaining to these requirements is optimized. We propose an algorithmic framework for solving these optimal embedding problems via a multistep feasibility approach that combines projections onto convex sets (POCS) based feasibility watermarking with a bisection parameter search for determining the optimum value of the objective function and the optimum watermarked image. The framework is general and can handle optimal watermark embedding problems with convex and quasi-convex formulations of watermark requirements with assured convergence to the global optimum. The proposed scheme is a natural extension of set-theoretic watermark design and provides a link between convex feasibility and optimization formulations for watermark embedding. We demonstrate a number of optimal watermark embeddings in the proposed framework corresponding to maximal robustness to additive noise, maximal robustness to compression, minimal frequency weighted perceptual distortion, and minimal watermark texture visibility. Experimental results demonstrate that the framework is effective in optimizing the desired characteristic while meeting the constraints. The results also highlight both anticipated and unanticipated competition between the common requirements for watermark embedding.
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763
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Sharma G, Mirza S, Parshad R, Gupta SD, Pandaya P, Ralhan R. Prognostic significance of GSTP1 and MGMT hypermethylation in invasive ductal breast carcinoma patients. Cancer Res 2009. [DOI: 10.1158/0008-5472.sabcs-4053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Abstract #4053
Purpose: Methylation-mediated suppression of detoxification, DNA repair and tumor suppressor genes has been implicated in cancer development, by shifting cells from the normal cellular cycle to a state of high proliferation that favors tumor development and progression. The current study was designed to analyze the methylation status of these genes in sera of breast cancer patients and determine the correlation of promoter hypermethylation of these genes with disease prognosis and patient survival.
 Experimental design: To test the hypothesis that promoter methylation of GSTP1 and MGMT is associated with disease prognosis, the methylation status of these genes was analyzed in invasive ductal carcinoma tissues and corresponding sera of breast cancer patients and correlated with disease free survival of these patients.
 Results: Promoter methylation of GSTP1 and MGMT was observed in 25% and 38% of breast tumor tissues, respectively and in 23% and 35% of the corresponding sera of breast cancer patients. There was significant association between methylation of GSTP1 and advanced tumor stage. Patients harboring methylated GSTP1 were more likely to have disease progression and reduced overall survival compared with patients who did not have the methylated gene.
 Conclusion: GSTP1 methylation in tumor and sera may serve as a poor prognostic marker in patients with invasive ductal carcinoma.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4053.
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764
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Sharma G, Vijayaraghavan S. Nicotinic receptors containing the alpha7 subunit: a model for rational drug design. Curr Med Chem 2009; 15:2921-32. [PMID: 19075644 DOI: 10.2174/092986708786848703] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The neuronal nicotinic receptor has gained considerable recognition as a target, not just for combating drug addiction but also for treating a number of illnesses ranging from neurodegenerative diseases to psychotic disorders like schizophrenia. This recognition has led to a burgeoning field examining the receptor at all levels. A class of nicotinic receptors that contains the alpha7 gene product, apparently as a homomer, illustrates this multidisciplinary approach. Here, we review recent progress in our understanding of this class of receptors based on data from molecular, structural, physiological and patho-physiological studies. These studies have set the stage for rational drug design to combat disorders of the central nervous system. The studies also exemplify the cautious approach needed in developing CNS therapies and the importance of physiology in tempering drug design.
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765
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Mogalicherla AK, Sharma G, Kunzru D. Estimation of Wetting Efficiency in Trickle-Bed Reactors for Nonlinear Kinetics. Ind Eng Chem Res 2009. [DOI: 10.1021/ie801305t] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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766
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Nagpal A, Pai KM, Setty S, Sharma G. Localization of impacted maxillary canines using panoramic radiography. J Oral Sci 2009; 51:37-45. [PMID: 19325198 DOI: 10.2334/josnusd.51.37] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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767
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Wilson L, Kyriacou N, Brooks A, John B, Dimitri H, Lau D, Lim H, Alasady M, Sharma G, Namboodiri N, Young G, Sanders P. Cartosound Imaging during Atrial Fibrillation Ablation Identifies the Real-time Left Atrial–oesophageal Relationship. Heart Lung Circ 2009. [DOI: 10.1016/j.hlc.2009.05.319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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768
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Mascarenhas AA, Thomas I, Sharma G, Cherian JJ. Clinical and radiological instability following standard fenestration discectomy. Indian J Orthop 2009; 43:347-51. [PMID: 19838384 PMCID: PMC2762566 DOI: 10.4103/0019-5413.55465] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Post-surgical lumbar instability is an established complication but there is limited evidence in the literature regarding the incidence of lumbar instability following fenestration and discectomy. We analyzed our results following fenestration discectomy with a special focus on instability. MATERIALS AND METHODS Eighty-three patients between the age of 17 and 52 years who had undergone fenestration discectomy for a single-level lumbar intervertebral disc prolapse were followed-up for a period of 1-5 years. The criteria for instability included "instability catch,", "painful catch," and "apprehension." The working capacity of the patient and the outcome score of the surgery were assessed by means of the Oswestry disability score and the Prolo economic and functional outcome score. Flexion-extension lateral radiographs were taken and analyzed for abnormal tilt and translation. RESULTS Of the 83 patients included, 70 were men and 13 were women, with an average age of 37.35 years (17-52 years) at 5 years follow-up. Clinical instability was seen in 10 (12.04%) patients. Radiological instability was noted in 29 (34.9%) patients. Only six (60%) of the 10 patients who demonstrated clinical instability had radiological evidence of instability. Twenty (68.96%) patients with radiological instability were asymptomatic. Three (10.34%) patients with only radiological instability had unsatisfactory outcome. The Oswestry scoring showed an average score of 19.8%. Mild disability was noted in 59 (71.08%) patients and moderate disability was seen in 24 (28.91%) patients. None of the patients had severe disability. These outcomes were compared with the outcomes in other studies in the literature for microdiscectomy and the results were found to be comparable. CONCLUSION The favorable outcome of this study is in good agreement with other studies on microdiscectomy. Clinical instability in 12.04% of the patients is in agreement with other studies. Radiological signs of instability are seen even in asymptomatic patients and so are not as reliable as clinical signs of instability. Standard fenestration discectomy does not destabilize the spine more than microdiscectomy.
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769
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Bhatt RB, Sharma G, Dhall A, Chaudhury S. Efficient Skin Region Segmentation Using Low Complexity Fuzzy Decision Tree Model. 2009 ANNUAL IEEE INDIA CONFERENCE 2009. [DOI: 10.1109/indcon.2009.5409447] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
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770
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Jain DK, Amaravati R, Sharma G. Evaluation of the clinical signs of anterior cruciate ligament and meniscal injuries. Indian J Orthop 2009; 43:375-8. [PMID: 19838388 PMCID: PMC2762557 DOI: 10.4103/0019-5413.55466] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND The diagnostic accuracy of anterior drawer (AD) sign, Lachman test and the pivot shift test for anterior cruciate ligament injury and McMurray test for medial and lateral meniscus is varied with sensitivity and specificity ranging from 2 to 100%. Generally, it is accepted that the pivot shift test is the most specific test to diagnose anterior cruciate ligament (ACL) tears and that the Lachman test is more sensitive than AD sign. This study was undertaken to calculate the sensitivity, specificity, positive predictive value, negative predictive value, and efficiency for the above-mentioned diagnostic tests. MATERIALS AND METHODS Twenty-eight male patients with clinical ACL injury were examined in the outpatient department and under anaesthesia, the findings were compared with arthroscopy. RESULT The sensitivity and specificity for the Lachman test, AD sign and pivot shift test performed in the outpatient setting are 78.6 and 100%, 89.3 and 100%, and 75 and 100%, respectively. The sensitivity and specificity for the Lachman test, AD sign, and pivot shift test performed under anesthesia are 92.9 and 100%, 92.9 and 100%, and 100 and 100%, respectively. The sensitivity and specificity of the McMurray test for medial and lateral meniscus were 35.7 and 85.7% and 22.2 and 100%, respectively. CONCLUSION The Lachman test, AD sign and pivot shift test are highly specific tests to diagnose ACL laxity in a non-acute setting; pivot shift test under anesthesia is the most sensitive and specific test for diagnosing ACL laxity in a non-acute setting and the McMurray test is not a sensitive test to diagnose meniscal injury in the presence of ACL injury.
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771
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Sharma G, Dhall A, Chaudhury S, Bhatt R. Hierarchical System for Content Based Categorization and Orientation of Consumer Images. LECTURE NOTES IN COMPUTER SCIENCE 2009:495-500. [DOI: 10.1007/978-3-642-11164-8_80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
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772
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Wilson L, Brooks A, Kyriacou N, John B, Dimitri H, Lau D, Lim H, Alasady M, Sharma G, Namboodiri N, Young G, Sanders P. Temporal Changes in the Left Atrial–Oesophageal Relationship at Annual Review Post-Atrial Fibrillation Ablation. Heart Lung Circ 2009. [DOI: 10.1016/j.hlc.2009.05.371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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773
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Sharma G, Chaudhury S, Srivastava J. Object Category Detection by Statistical Test of Hypothesis. 2008 SIXTH INDIAN CONFERENCE ON COMPUTER VISION, GRAPHICS & IMAGE PROCESSING 2008. [DOI: 10.1109/icvgip.2008.83] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
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774
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Sharma G, Chaudhury S, Srivastava J. Bag-of-features kernel eigen spaces for classification. 2008 19TH INTERNATIONAL CONFERENCE ON PATTERN RECOGNITION 2008. [DOI: 10.1109/icpr.2008.4761240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
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775
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Sharma G, Anabousi S, Ehrhardt C, Ravi Kumar MNV. Liposomes as targeted drug delivery systems in the treatment of breast cancer. J Drug Target 2008; 14:301-10. [PMID: 16882550 DOI: 10.1080/10611860600809112] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Solid tumors such as breast cancer have historically provided many challenges to anti-cancer therapy. Therapeutic hurdles to drug penetration in solid tumors include heterogeneous vascular supply and high interstitial pressures within tumor tissue, particularly in necrotic zones, lower pH and presence of leaky vasculature leading to reduced therapeutic response. Liposome based drug delivery systems offer the potential to enhance the therapeutic index of anti-cancer agents, either by increasing the drug concentration in tumor cells and/or by decreasing the exposure in normal tissues exploiting enhanced permeability and retention effect phenomenon and by utilizing targeting strategies. This review discusses recent trends in liposome-based drug delivery system both for diagnosis and treatment of breast cancer.
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776
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Mandlik RV, Desai SK, Naik SR, Sharma G, Kohli RK. Antidiabetic activity of a polyherbal formulation (DRF/AY/5001). INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 2008; 46:599-606. [PMID: 18814489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The herbal formulation, DRF/AY/5001, elicits hypoglycemic/antidiabetic effects in both normal and experimentally induced hyperglycemic (epinephrine and alloxan) rats. Further, herbal formulation treatment can significantly alter the pattern of glucose tolerance in normal and diabetic rats. It is possible that the herbal formulation may act through both, pancreatic and extra-pancreatic mechanism(s). The DRF/AY/5001 also elicited a significant antioxidant effect in alloxan diabetic rats as reflected by its ability to inhibit lipid peroxidation and to elevate the enzymatic antioxidants in pancreatic tissue. The histopathological studies during the long-term treatment have shown to ameliorate the alloxan induced histological damage of islets of Langerhans. The inhibitory effects on biochemical and histological parameters induced by herbal formulation at a dose of 600 mg/kg were almost comparable to that of standard drug, glibenclamide (4 mg/kg). The present study demonstrates that herbal formulation exhibits promisisng antidiabetic activity and helps to maintain good glycemic and metabolic control.
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777
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Sharma G, Pai KM, Setty S, Ramapuram JT, Nagpal A. Oral manifestations as predictors of immune suppression in a HIV-/AIDS-infected population in south India. Clin Oral Investig 2008; 13:141-8. [PMID: 18668269 DOI: 10.1007/s00784-008-0210-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2007] [Accepted: 06/12/2008] [Indexed: 02/07/2023]
Abstract
The objectives of the study are to evaluate the relationship between common HIV-related oral lesions and absolute CD4+ count, age, gender, and medication used and to assess the sensitivity, specificity, positive and negative predictive value of oral manifestations for low absolute CD4+ counts. HIV-positive patients, 200, from south India were selected, whose absolute CD4+ counts were determined within 2 weeks of oral examination. Sociodemographic data was obtained using a structured questionnaire. Oral manifestations were diagnosed according to presumptive criteria of EEC-clearinghouse classification (1993). Four or more concurrent oral lesions were statistically significant with low CD4+ counts <200 cells/mm3 (P = 0.005). The highest and lowest mean CD4+ cell counts were seen in individuals with linear gingival erythema (LGE; 172.5 cells/mm(3)) and pseudomembranous candidiasis (PC; 87 cells/mm(3)), respectively. Smoking, age (<35 years), and males had a positive association with oral hairy leukoplakia (OHL; P < 0.05). Patients with CD4+ counts < 200 cells/mm(3) were associated with 15 times greater risk of PC and four times at greater risk for occurrence of any oral manifestation. Concurrent oral manifestations (>or=4) were good predictors (80-100%) of severe immune suppression. In most resource poor countries where facilities for undertaking CD4+ counts are not available, the presence of concurrent oral manifestations may be used as an indicator of deteriorating immune status.
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778
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Roche J, Potiron V, Nasarre P, Sharma G, Gemmill R, Drabkin H. SEMA3F Semaphorin is involved in tumor angiogenesis. EJC Suppl 2008. [DOI: 10.1016/s1359-6349(08)71270-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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779
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Balaji A, Sharma G, Shaw M, Guay R. Preprocessing Methods for Improved Lossless Compression of Color Look-up Tables. J Imaging Sci Technol 2008. [DOI: 10.2352/j.imagingsci.technol.(2008)52:4(040901)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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780
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Sharma G, Koley S, Sandhu JS, Kajal NC, Jorawar S. A study of changes in the body composition components in the patients with pulmonary tuberculosis. THE MEDICAL JOURNAL OF MALAYSIA 2008; 63:118-121. [PMID: 18942296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The present study deals with the analysis of body composition components of 86 randomly selected patients with confirmed pulmonary tuberculosis aged 16- 70 years collected from the District Tuberculosis Centre and Hospital, Amritsar. An adequate number of controls were also taken for comparison. The findings of the present study showed highly significant differences (p < or = 0.001) in all the twelve kinanthropometric variables except height. When the data was further analyzed between sputum negative and sputum positive patients with pulmonary tuberculosis, highly significant differences (p < or = 0.001) were found only in total body fat and statistically significant differences (p < or = 0.05) were observed in weight, chest circumference in normal position, abdominal circumference, right calf and buttock circumferences. It may be concluded that TB patients were more malnourished than normal people. Thus, special nutritional care should be taken to the TB patients to give them a better quality of life.
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781
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Sharma G, Kumar R, Chakraborti AK. ‘On water’ synthesis of 2,4-diaryl-2,3-dihydro-1,5-benzothiazepines catalysed by sodium dodecyl sulfate (SDS). Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.04.146] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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782
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Doshi D, Ramapuram JT, Anup N, Sharma G. Correlation of CD4 cell count with gingival bleeding index in HIV positive individuals. Med Oral Patol Oral Cir Bucal 2008; 13:E348-E351. [PMID: 18521053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
OBJECTIVES To correlate CD4 cell count with gingival bleeding index in HIV positive individuals. METHODS Fifty-one serologically confirmed HIV positive individuals were included in the study. Plaque index and bleeding index was recorded by a single examiner. CD4 cell count was obtained within 30 days from the day of examination. CD4 cell counts and gingival bleeding index was correlated using Spearman's correlation test. p < 0.01 was considered as statistically significant. RESULTS Mean plaque score, mean gingival bleeding index score and mean CD4 cell count was 1.40, 0.96 and 249.86 cells/mm3 respectively. It was noticed that gingival bleeding was enhanced in individuals with increased immunosuppression. However, no significant positive correlation was seen between mean CD4 cell count and gingival bleeding (p = 0.14). CONCLUSION Though CD4 cells are an important indicator for clinical aggravation of HIV infection, periodontal disease as measured by bleeding index is not directly associated to the cell count.
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783
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Sharma G, Kumar R, Chakraborti AK. Fluoroboric acid adsorbed on silica-gel (HBF4–SiO2) as a new, highly efficient and reusable heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.04.144] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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784
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Sharma G, Gargi J, Kalsey G, Singh D, Rai H, Sandhu R. Determination of age from pubic symphysis: an autopsy study. MEDICINE, SCIENCE, AND THE LAW 2008; 48:163-169. [PMID: 18533578 DOI: 10.1258/rsmmsl.48.2.163] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The present study was conducted on three hundred and thirty-six cases brought for autopsy to the Department of Forensic Medicine, Government Medical College, Amritsar, Punjab, India, during the period 2000-2002. Pubic bones of either sex were analysed according to Todd's method (1920; 1921a,b,c) as modified by McKern and Stewart (1957) to assess and compare the known age of the corpses. Cases belonged to both sexes, i.e. 79.46% males and 20.54% females. All the cases were above the age of 17 years. No difference was noted in the scoring of right and left pubic bones. The age estimation from different components in males and females up to the total score of 10 (23-28 years) was +/- 6, whereas above a score of 10 the estimated age was +/- 12 in males and +/- 9 in females. The age range given for scores of 14 and 15, which were 29+ and 36+ respectively, did not account for variability of age after 40 years. Therefore, the age assessment from pubic bones in the fourth decade age group and beyond is not reliable which is in variance to the study by McKern and Stewart (1957).
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785
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Harmanci AO, Sharma G, Mathews DH. PARTS: probabilistic alignment for RNA joinT secondary structure prediction. Nucleic Acids Res 2008; 36:2406-17. [PMID: 18304945 PMCID: PMC2367733 DOI: 10.1093/nar/gkn043] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A novel method is presented for joint prediction of alignment and common secondary structures of two RNA sequences. The joint consideration of common secondary structures and alignment is accomplished by structural alignment over a search space defined by the newly introduced motif called matched helical regions. The matched helical region formulation generalizes previously employed constraints for structural alignment and thereby better accommodates the structural variability within RNA families. A probabilistic model based on pseudo free energies obtained from precomputed base pairing and alignment probabilities is utilized for scoring structural alignments. Maximum a posteriori (MAP) common secondary structures, sequence alignment and joint posterior probabilities of base pairing are obtained from the model via a dynamic programming algorithm called PARTS. The advantage of the more general structural alignment of PARTS is seen in secondary structure predictions for the RNase P family. For this family, the PARTS MAP predictions of secondary structures and alignment perform significantly better than prior methods that utilize a more restrictive structural alignment model. For the tRNA and 5S rRNA families, the richer structural alignment model of PARTS does not offer a benefit and the method therefore performs comparably with existing alternatives. For all RNA families studied, the posterior probability estimates obtained from PARTS offer an improvement over posterior probability estimates from a single sequence prediction. When considering the base pairings predicted over a threshold value of confidence, the combination of sensitivity and positive predictive value is superior for PARTS than for the single sequence prediction. PARTS source code is available for download under the GNU public license at http://rna.urmc.rochester.edu.
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786
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Singh P, Kaur G, Sharma G, Mehra NK. Immunogenetic basis of HIV-1 infection, transmission and disease progression. Vaccine 2008; 26:2966-80. [PMID: 18321617 DOI: 10.1016/j.vaccine.2008.01.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Revised: 01/09/2008] [Accepted: 01/09/2008] [Indexed: 10/22/2022]
Abstract
Susceptibility to HIV-1 infection and rate of disease progression to AIDS are complex traits modulated by environmental and genetic factors. Studies on large AIDS cohorts and their meta-analyses have identified numerous AIDS restriction genes that regulate HIV cell entry (particularly chemokine co-receptors and their ligands), acquired and innate immunity (major histocompatibility complex (MHC), killer immunoglobulin-like receptors (KIRs), and cytokines) and others that influence outcome of HIV infection. However, vast inter-individual variability is often observed and some rare individuals like 'long-term non-progressors (LTNPs) or exposed uninfected' (EUs) appear to be protected due to natural resistance. A better understanding of genetic basis of such a 'natural resistance' to infection would bear important implications in designing therapeutic vaccine designs. The genetic variants that could limit AIDS vary in different populations. We have studied genetic variations in the MHC, cytokines and CCR2-CCR5 loci in the Asian-Indian HIV-infected population and compared with other global populations.
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787
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Sharma G, Singh SV, Sevilla I, Singh AV, Whittington RJ, Juste RA, Kumar S, Gupta VK, Singh PK, Sohal JS, Vihan VS. Evaluation of indigenous milk ELISA with m-culture and m-PCR for the diagnosis of Bovine Johne’s disease (BJD) in lactating Indian dairy cattle. Res Vet Sci 2008; 84:30-7. [PMID: 17544046 DOI: 10.1016/j.rvsc.2007.03.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Revised: 03/04/2007] [Accepted: 03/30/2007] [Indexed: 11/28/2022]
Abstract
Present study is the first attempt to evaluate an indigenous milk ELISA with milk culture, standardize milk PCR, estimate lacto-prevalence of Map and genotype Map DNA from milk samples in few Indian dairy herds. In all 115 cows were sampled from 669 lactating cows in six dairy herds from three districts of North India. Fifty milk samples (four herds) were screened by three tests (milk culture, m-ELISA and m-PCR). Lacto-prevalence of Map in four dairy herds was 84.0% (50.0% in fat and 62.0% in sediment). Screening of both fat and sediment increased the sensitivity of culture. Colonies appeared between 45 and 120 DPI. In indigenous m-ELISA, protoplasmic antigen derived from native Map 'Bison type' strain of goat origin was used. Screening of 115 lactating cows by m-ELISA ('herd screening test') detected 32.1% positive lactating cows (lacto-prevalence). Sensitivity of ELISA was 28.5% and 42.8% in single point cutoff and S/P ratio, respectively. Lacto-prevalence of JD was high in dairy herds (66.6-100.0% by culture and 20.0-50.0% by m-ELISA). DDD farm, Mathura had very high (95.8%) and moderate prevalence of Map and lacto-antibodies, respectively. All cows were clinically suffering from JD. Specific IS 900 PCR was standardized in decontaminated fat and sediment of milk samples. DNA isolated from decontaminated pellets was amplified and characteristic 229 bp band was confirmatory for Map. Of the 50 milk samples, 6.0% were positive in m-PCR. The test needs further standardization. Map DNA were genotyped as Map 'Bison type' by IS 1311 PCR-REA. Of the three tests, milk culture was most sensitive followed by m-ELISA and m-PCR. Map DNA isolated from milk samples of dairy cattle were first time genotyped as Map, 'Bison type' in India. High prevalence of Map in milk of dairy herds, posed major health hazard for calves and human beings.
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788
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Kumar S, Singh S, Sevilla I, Singh A, Whittington R, Juste R, Sharma G, Singh P, Sohal J. Lacto-prevalence, genotyping of Mycobacterium avium subspecies paratuberculosis and evaluation of three diagnostic tests in milk of naturally infected goatherds. Small Rumin Res 2008. [DOI: 10.1016/j.smallrumres.2007.03.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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789
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Sharma G, Rege K, Budil DE, Yarmush ML, Mavroidis C. Reversible pH-controlled DNA-binding peptide nanotweezers: an in-silico study. Int J Nanomedicine 2008; 3:505-21. [PMID: 19337419 PMCID: PMC2636583 DOI: 10.2147/ijn.s4046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We describe the molecular dynamics (MD)-aided engineering design of mutant
peptides based on the α-helical coiled-coil GCN4 leucine zipper
peptide (GCN4-p1) in order to obtain environmentally-responsive nanotweezers.
The actuation mechanism of the nanotweezers depends on the modification of
electrostatic charges on the residues along the length of the coiled coil.
Modulating the solution pH between neutral and acidic values results in the
reversible movement of helices toward and away from each other and creates a
complete closed-open-closed transition cycle between the helices. Our results
indicate that the mutants show a reversible opening of up to 15 Å
(1.5 nm; approximately 150% of the initial separation) upon pH
actuation. Investigation on the physicochemical phenomena that influence
conformational properties, structural stability, and reversibility of the
coiled-coil peptide-based nanotweezers revealed that a rationale- and
design-based approach is needed to engineer stable peptide or macromolecules
into stimuli-responsive devices. The efficacy of the mutant that demonstrated
the most significant reversible actuation for environmentally responsive
modulation of DNA-binding activity was also demonstrated. Our results have
significant implications in bioseparations and in the engineering of novel
transcription factors.
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790
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791
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Blanchard F, Razzari L, Bandulet HC, Sharma G, Morandotti R, Kieffer JC, Ozaki T, Reid M, Tiedje HF, Haugen HK, Hegmann FA. Generation of 1.5 microJ single-cycle terahertz pulses by optical rectification from a large aperture ZnTe crystal. OPTICS EXPRESS 2007; 15:13212-13220. [PMID: 19550589 DOI: 10.1364/oe.15.013212] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We demonstrate the generation muJ-level, single-cycle terahertz pulses by optical rectification from a large-aperture ZnTe single crystal wafer. Energies up to 1.5 muJ per pulse and a spectral range extending to 3 THz were obtained using a 100 Hz Ti:sapphire laser source and a 75-mmdiameter, 0.5-mm-thick, (110) ZnTe crystal, corresponding to an average power of 150 muW and an energy conversion efficiency of 3.1 x 10(-5). We also demonstrate real-time imaging of the focused terahertz beam using a pyroelectric infrared camera.
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792
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Mahajan N, Dhawan V, Sharma G, Jain S, Kaul D. ‘Induction of inflammatory gene expression by THP-1 macrophages cultured in normocholesterolaemic hypertensive sera and modulatory effects of green tea polyphenols’. J Hum Hypertens 2007; 22:141-3. [PMID: 17728801 DOI: 10.1038/sj.jhh.1002277] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hypertension is a disorder controlled by multiple genes and inflammation and vascular remodelling of arteries have been implicated in pathogenesis of this disease. Green tea polyphenols (GrTPs) are rich in antioxidants and are known to inhibit inflammatory responses. A significant time-dependent increase in mRNA expression of both IL-6 and MMP-9 were observed in THP-1 macrophages when cultured in normocholesterolaemic hypertensive sera (P<0.05).
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793
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Kaur G, Singh P, Kumar N, Rapthap CC, Sharma G, Vajpayee M, Wig N, Sharma SK, Mehra NK. Distribution of CCR2 polymorphism in HIV-1-infected and healthy subjects in North India. Int J Immunogenet 2007; 34:153-6. [PMID: 17504503 DOI: 10.1111/j.1744-313x.2007.00667.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Substitution of V64I in CCR2 relates to delayed progression to AIDS and protects against HIV-1 infection. We examined the distribution of V64I in HIV-infected and healthy North Indian subjects. No significant difference in the allele or genotype distribution of CCR2 V64I polymorphism was observed, indicating that there is no association between CCR2 V64I polymorphism and susceptibility to HIV infection in North Indian population.
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794
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Cherukupalli G, Sharma G, Ramana Rao M, Kunwar A. Stereoselective Synthesis of Carbon-Carbon-Linked Deoxy Disaccharides. SYNTHESIS-STUTTGART 2007. [DOI: 10.1055/s-2007-983751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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795
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Sharma G, Sharma R, Sharma E. Influence of stand age on nutrient and energy release through decomposition in alder-cardamom agroforestry systems of the eastern Himalayas. Ecol Res 2007. [DOI: 10.1007/s11284-007-0377-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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796
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Kashyap N, Viswanad B, Sharma G, Bhardwaj V, Ramarao P, Ravi Kumar MNV. Design and evaluation of biodegradable, biosensitive in situ gelling system for pulsatile delivery of insulin. Biomaterials 2007; 28:2051-60. [PMID: 17240443 DOI: 10.1016/j.biomaterials.2007.01.007] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Accepted: 01/01/2007] [Indexed: 11/23/2022]
Abstract
Biodegradable glucose-sensitive in situ gelling system based on chitosan for pulsatile delivery of insulin was developed. The sols/gels were thoroughly characterized for swelling properties, rheology, texture analysis and water content. The developed glucose-sensitive gels responded to varied glucose concentrations in vitro indicating their ability to function as environment-sensitive systems. Insulin load onto the gels was optimized and was found to affect the rheological behavior of these gels, the final preparation used for in vitro contained 1IU/200mul of the sol. These gels released the entrapped insulin in a pulsatile manner in response to the glucose concentration in vitro. Furthermore, the formulations when evaluated for their in vivo efficacy in streptozotocin-induced diabetic rats at a dose of 3IU/kg, demonstrated their ability to release insulin in response to glucose concentration and were preferred much better against subcutaneously given plain insulin formulation used as the control. Together, these preliminary results indicate that biosensitive chitosan in situ gelling systems have substantial potential as pulsatile delivery systems for insulin.
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797
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Sonaje K, Italia JL, Sharma G, Bhardwaj V, Tikoo K, Kumar MNVR. Development of Biodegradable Nanoparticles for Oral Delivery of Ellagic Acid and Evaluation of Their Antioxidant Efficacy Against Cyclosporine A-Induced Nephrotoxicity in Rats. Pharm Res 2007; 24:899-908. [PMID: 17377747 DOI: 10.1007/s11095-006-9207-y] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 12/04/2006] [Indexed: 12/11/2022]
Abstract
PURPOSE Ellagic acid (EA), a dietary antioxidant associated with poor biopharmaceutical properties, was encapsulated into poly(lactide-co-glycolide) (PLGA) and polycaprolactone (PCL) nanoparticles to improve oral bioavailability. MATERIALS AND METHODS EA-loaded nanoparticles were prepared following emulsion-diffusion-evaporation method employing didodecyldimethyl ammonium bromide (DMAB) and polyvinyl alcohol (PVA) as stabilizers. In vitro release was investigated in phosphate buffer (pH 7.4). The in situ permeation studies were performed in rats. The antioxidant potential of the DMAB-stabilized nanoparticulate formulations was evaluated against cyclosporine A (CyA)-induced nephrotoxicity in rats. RESULTS EA-loaded PLGA and PCL nanoparticles have been successfully prepared employing PEG 400 as co-solvent to solubilize EA. The stabilizers influenced the particle size and encapsulation efficiency. DMAB when used as stabilizer to particles of approximately 120 nm and approximately 50% encapsulation, whereas PVA led to approximately 290 nm and approximately 60% encapsulation at 5% initial loading (w/w of polymer). The in vitro release of EA from the nanoparticles followed Higuchi's square root pattern and was faster with PVA-stabilized particles in comparison to those stabilized with DMAB. From the in situ permeation studies in rats, it was evident that intestinal uptake of EA as DMAB-stabilized nanoparticles was significantly higher as compared to the sodium carboxymethyl cellulose suspension and the PVA-stabilized particles. EA and EA nanoparticles were able to prevent the CyA-induced nephrotoxicity in rats as evident by biochemical parameters as well as kidney histopathology. CONCLUSION The present study demonstrates the potential of EA nanoparticulate formulations in the prevention of CyA-induced nephrotoxicity at three times lower dose suggesting improved oral bioavailability of EA.
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798
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Sharma G, Kumar M, Ram D. The efficacy and side effect profile of lamotrigine in acute mania: A double-. Eur Psychiatry 2007. [DOI: 10.1016/j.eurpsy.2007.01.870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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799
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Sharma G, Italia JL, Sonaje K, Tikoo K, Ravi Kumar MNV. Biodegradable in situ gelling system for subcutaneous administration of ellagic acid and ellagic acid loaded nanoparticles: Evaluation of their antioxidant potential against cyclosporine induced nephrotoxicity in rats. J Control Release 2007; 118:27-37. [PMID: 17258836 DOI: 10.1016/j.jconrel.2006.11.026] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Revised: 11/22/2006] [Accepted: 11/25/2006] [Indexed: 11/25/2022]
Abstract
Ellagic acid (EA) is a potent antioxidant marketed as a nutritional supplement. Its pharmacological activity has been reported in wide variety of disease models; however its use has been limited owing to its poor biopharmaceutical properties, thereby poor bioavailability. The objective of the current study was to develop chitosan-glycerol phosphate (C-GP) in situ gelling system for sustained delivery of ellagic acid (EA) via subcutaneous route. EA was incorporated in the system employing propylene glycol (PG) and triethanolamine (TEA) as co-solvents; on the other hand EA loaded PLGA nanoparticles (np) were dispersed in the gelling system using water. These in situ gelling systems were thoroughly characterized for mechanical, rheological and swelling properties. These systems are liquid at room temperature and gels at 37 degrees C. The EA C-GP system showed an initial burst release in vitro with about 85% drug released in 12 h followed by a steady release till 160 h, on the other hand EA nanoparticles entrapped in the C-GP system displayed sustained release till 360 h. The histopathological analysis indicates the absence of inflammation on administration, suggesting that these formulations are safe during the studied period. Furthermore, the antioxidant potential of EA C-GP and EA np C-GP gels has been evaluated against cyclosporine induced nephrotoxicity in rats. The data indicates that formulations were effective against cyclosporine induced nephrotoxicity, where the EA C-GP gels showed activity at 10 times lower dose and the EA np C-GP gels at 150 times lower dose when compared to orally given EA. Formulating nanoparticles of EA and incorporating them in C-GP system results in 15 times lowering of dose in comparison EA C-GP gels which is quite significant. Together, these results indicate that the bioavailability of ellagic acid can be improved by subcutaneous formulations administered as simple EA or EA nps.
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800
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Sharma G, Kumar R, Chakraborti AK. A novel environmentally friendly process for carbon–sulfur bond formation catalyzed by montmorillonite clays. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.molcata.2006.08.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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