• 제목/요약/키워드: VARMA

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Cloning and Characterization of ${\Delta}^1$-Pyrroline-5-Carboxylate Synthetase Genes and Identification of Point Mutants in Medicago truncatula

  • Song, Ki-Hoon;Song, Dae-Hae;Lee, Jeong-Ran;Kim, Goon-Bo;Choi, Hong-Kyu;Penmetsa, R. Varma;Nam, Young-Woo
    • 한국작물학회지
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    • 제52권4호
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    • pp.458-468
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    • 2007
  • To tolerate environmentally adverse conditions such as cold, drought, and salinity, plants often synthesize and accumulate proline in cells as compatible osmolytes. ${\Delta}^1$-Pyrroline-5-carboxylate synthetase(P5CS) catalyzes the rate-limiting step of proline biosynthesis from glutamate. Two complete genes, MtP5CS1 and MtP5CS2, were isolated from the model legume Medicago truncatula by cDNA cloning and bacterial artificial chromosome library screening. Nucleotide sequence analysis showed that both genes consisted of 20 exons and 19 introns. Alignment of the predicted amino acid sequences revealed high similarities with P5CS proteins from other plant species. The two MtP5CS genes were expressed in response to high salt and low temperature treatments. Semi-quantitative reverse transcription-polymerase chain reaction showed that MtP5CS1 was expressed earlier than MtP5CS2, indicating differential regulation of the two genes. To evaluate the reverse genetic effects of nucleotide changes on MtP5CS function, a Targeting Induced Local Lesions in Genomes approach was taken. Three mutants each were isolated for MtP5CS1 and MtP5CS2, of which a P5CS2 nonsense mutant carrying a codon change from arginine to stop was expected to bring translation to premature termination. These provide a valuable genetic resource with which to determine the function of the P5CS genes in environmental stress responses of legume crops.

Comparison of Interferon-γ Release Assays and the Tuberculin Skin Test for Diagnosis of Tuberculosis in Human Immunodeficiency Virus: A Systematic Review

  • Overton, Kristen;Varma, Rick;Post, Jeffrey J.
    • Tuberculosis and Respiratory Diseases
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    • 제81권1호
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    • pp.59-72
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    • 2018
  • Background: It remains uncertain if $interferon-{\gamma}$ release assays (IGRAs) are superior to the tuberculin skin test (TST) for the diagnosis of active tuberculosis (TB) or latent tuberculosis infection (LTBI) in immunosuppressed populations including people with human immunodeficiency virus (HIV) infection. The purpose of this study was to systematically review the performance of IGRAs and the TST in people with HIV with active TB or LTBI in low and high prevalence TB countries. Methods: We searched the MEDLINE database from 1966 through to January 2017 for studies that compared results of the TST with either the commercial QuantiFERON-TB Gold in Tube (QFTGT) assay or previous assay versions, the T-SPOT.TB assay or in-house IGRAs. Data were summarized by TB prevalence. Tests for concordance and differences in proportions were undertaken as appropriate. The variation in study methodology was appraised. Results: Thirty-two studies including 4,856 HIV subjects met the search criteria. Fourteen studies compared the tests in subjects with LTBI in low TB prevalence settings. The QFTGT had a similar rate of reactivity to the TST, although the first-generation version of that assay was reactive more commonly. IGRAs were more frequently positive than the TST in HIV infected subjects with active TB. There was considerable study methodology and population heterogeneity, and generally low concordance between tests. Both the TST and IGRAs were affected by CD4 T-cell immunodeficiency. Conclusion: Our review of comparative data does not provide robust evidence to support the assertion that the IGRAs are superior to the TST when used in HIV infected subjects to diagnose either active TB or LTBI.

A novel amnion-chorion allograft membrane combined with a coronally advanced flap: a minimally invasive surgical therapy to regenerate interdental papillary soft tissue recession - a six-month postoperative image analysis-based clinical trial

  • Pitale, Unnati;Pal, Pritish Chandra;Boyapati, Ramanarayana;Bali, Ashish;Varma, Manish;Khetarpal, Shaleen
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제47권6호
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    • pp.438-444
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    • 2021
  • Objectives: Loss of the interdental papilla is multi-factorial and creates a multitude of problems. Autogenous connective tissue/biomaterial-based regeneration has been attempted for decades to reconstitute the black space created due to the loss of papilla. The aim of this present study was to regenerate papillary recession defects using an amnion-chorion membrane (ACM) allograft and to evaluate the clinical outcome up to six months postoperatively. Materials and Methods: Twenty patients with 25 Nordland and Tarnow's Class I/II interdental papillary recession defects were treated with ACM and coronal advancement of the gingivo-papillary unit via a semilunar incision on the labial aspect followed by a sulcular incision in the area of interest. A photographic image analysis was carried out using the GNU Image Manipulation software program from the baseline to three and six months postoperatively. The black triangle height (BTH) and the black triangle width (BTW) were calculated using the pixel size and were then converted into millimeters. The mean and standard deviation values were determined at baseline and then again at three and six months postoperatively. The probability values (P<0.05 and P≤0.01) were considered statistically significant and highly significant, respectively. An analysis of variance and post hoc Bonferroni test were carried out to compare the mean values. Results: Our evaluation of the BTH and BTW showed a statistically and highly significant difference from the baseline until both three and six months postoperatively (P=0.01). A post hoc Bonferroni test disclosed a statistically significant variance from the baseline until three and six months postoperatively (P<0.05) and a non-significant difference from three to six months after the procedure (P≥0.05). Conclusion: An ACM allograft in conjunction with a coronally advanced flap could be a suitable minimally invasive alternative for papillary regeneration.

Effects of the COVID-19 Pandemic on Cardiac Surgery Practice and Outcomes

  • Gopal, Kirun;Krishna, Neethu;Jose, Rajesh;Biju, Surya Sree Chitra;Pichandi, Jaya Suriya;Varma, Praveen Kerala
    • Journal of Chest Surgery
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    • 제55권1호
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    • pp.61-68
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    • 2022
  • Background: While the coronavirus disease 2019 (COVID-19) pandemic has affected all aspects of health care, its impact on cardiac surgical practice and outcomes is yet to be determined. We compared the outcomes of our cardiac surgical practice from the past year during the pandemic to those in a similar pre-pandemic period. Methods: Retrospective data were collected from 307 patients who were involved in all adult cardiac surgical procedures performed between March 2020 and February 2021, which was considered the pandemic period, at Amrita Institute of Medical Sciences, India. These were compared with data from the 1-year period between March 2019 and February 2020. During that earlier period, 491 patients underwent surgery, and the surgical outcomes were assessed. Outpatient visit data were also collected to evaluate the effect of COVID-19 on outpatient follow-up visits. Results: A 37% decrease in surgical case volume was observed during the study period. No difference was found in operative mortality between the 2 time periods (3.3% vs. 2.6%, p=0.383). Overall postoperative complications were less frequent during this period, at 23% compared to 38% the previous year (p<0.001). Conclusion: The COVID-19 pandemic caused a dramatic decrease in surgical volume and outpatient medical follow-up. However, the pandemic and its attendant social restrictions did not yield a significant change in the surgical outcomes of our patients. Hence, it is reasonable to continue cardiac surgical care during global health crises, and this can be done with good results.

Evaluation of delamination in the drilling of CFRP composites

  • Feroz, Shaik;Ramakrishna, Malkapuram;K. Chandra, Shekar;P. Dhaval, Varma
    • Advances in materials Research
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    • 제11권4호
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    • pp.375-390
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    • 2022
  • Carbon Fiber Reinforced Polymer (CFRP) composite provides outstanding mechanical capabilities and is therefore popular in the automotive and aerospace industries. Drilling is a common final production technique for composite laminates however, drilling high-strength composite laminates is extremely complex and challenging. The delamination of composites during the drilling at the entry and exit of the hole has a severe impact on the results of the holes surface and the material properties. The major goal of this research is to investigate contemporary industry solutions for drilling CFRP composites: enhanced edge geometries of cutting tools. This study examined the occurrence of delamination at the entry and exit of the hole during the drilling. For each of the 80°, 90°, and 118°point angle uncoated Brad point, Dagger, and Twist solid carbide drills, Taguchi design of experiments were undertaken. Cutting parameters included three variable cutting speeds (100-125-150 m/min) and feed rates (0.1-0.2-0.3 mm/rev). Brad point drills induced less delamination than dagger and twist drills, according to the research, and the best cutting parameters were found to be a combination of maximum cutting speed, minimum feed rate, and low drill point angle (V:150 m/min, f: 0.1 mm/rev, θ: 80°). The feed rate was determined to be the most efficient factor in preventing hole entry and exit delamination using analysis of variance (ANOVA). Regression analysis was used to create first-degree mathematical models for each cutting tool's entrance and exit delamination components. The results of optimization, mathematical modelling, and experimental tests are thought to be reasonably coherent based on the information obtained.

In-silico and structure-based assessment to evaluate pathogenicity of missense mutations associated with non-small cell lung cancer identified in the Eph-ephrin class of proteins

  • Shubhashish Chakraborty;Reshita Baruah;Neha Mishra;Ashok K Varma
    • Genomics & Informatics
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    • 제21권3호
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    • pp.30.1-30.13
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    • 2023
  • Ephs belong to the largest family of receptor tyrosine kinase and are highly conserved both sequentially and structurally. The structural organization of Eph is similar to other receptor tyrosine kinases; constituting the extracellular ligand binding domain, a fibronectin domain followed by intracellular juxtamembrane kinase, and SAM domain. Eph binds to respective ephrin ligand, through the ligand binding domain and forms a tetrameric complex to activate the kinase domain. Eph-ephrin regulates many downstream pathways that lead to physiological events such as cell migration, proliferation, and growth. Therefore, considering the importance of Eph-ephrin class of protein in tumorigenesis, 7,620 clinically reported missense mutations belonging to the class of variables of unknown significance were retrieved from cBioPortal and evaluated for pathogenicity. Thirty-two mutations predicted to be pathogenic using SIFT, Polyphen-2, PROVEAN, SNPs&GO, PMut, iSTABLE, and PremPS in-silico tools were found located either in critical functional regions or encompassing interactions at the binding interface of Eph-ephrin. However, seven were reported in nonsmall cell lung cancer (NSCLC). Considering the relevance of receptor tyrosine kinases and Eph in NSCLC, these seven mutations were assessed for change in the folding pattern using molecular dynamic simulation. Structural alterations, stability, flexibility, compactness, and solvent-exposed area was observed in EphA3 Trp790Cys, EphA7 Leu749Phe, EphB1 Gly685Cys, EphB4 Val748Ala, and Ephrin A2 Trp112Cys. Hence, it can be concluded that the evaluated mutations have potential to alter the folding pattern and thus can be further validated by in-vitro, structural and in-vivo studies for clinical management.

Is central pancreatectomy an effective alternative to distal pancreatectomy for low-grade pancreatic neck and body tumors: A 20-year single-center propensity score-matched case-control study

  • Ashish Kumar Bansal;Bheerappa Nagari;Phani Kumar Nekarakanti;Amith Kumar Pakkala;Venu Madhav Thumma;Surya Ramachandra Varma Gunturi;Madhur Pardasani
    • 한국간담췌외과학회지
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    • 제27권1호
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    • pp.87-94
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    • 2023
  • Backgrounds/Aims: Central pancreatectomy (CP) is associated with a higher rate of postoperative pancreatic fistula (POPF), and it is less preferred over distal pancreatectomy (DP). We compared the short- and long-term outcomes between CP and DP for low-grade pancreatic neck and body tumors. Methods: This was a propensity score-matched case-control study of patients who underwent either CP or DP for low-grade pancreatic neck and body tumors from 2003 to 2020 in a tertiary care unit in southern India. Patients with a tumor >10 cm or a distal residual stump length of <4 cm were excluded. Demographics, clinical profile, intraoperative and postoperative parameters, and the long-term postoperative outcomes for exocrine and endocrine insufficiency, weight gain, and the 36-Item Short Form Survey (SF-36) quality of life questionnaire were compared. Results: Eighty-eight patients (CP: n=37 [cases], DP: n=51 [control]) were included in the unmatched group after excluding 21 patients (meeting exclusion criteria). After matching, both groups had 37 patients. The clinical and demographic profiles were comparable between the two groups. Blood loss and POPF rates were significantly higher in the CP group. However, Clavien-Dindo grades of complications were similar between the two groups (p = 0.27). At a median follow-up of 38 months (range = 187 months), exocrine sufficiency was similar between the two groups. Endocrine sufficiency, weight gain, SF-36 pain control score, and general health score were significantly better in the CP group. Conclusions: Despite equivalent clinically significant morbidities, long-term outcomes are better after CP compared to DP in low-grade pancreatic body tumors.

Structural evaluation of degradation products of Loteprednol using LC-MS/MS: Development of an HPLC method for analyzing process-related impurities of Loteprednol

  • Rajesh Varma Bhupatiraju;Bikshal Babu Kasimala;Lavanya Nagamalla;Fathima Sayed
    • 분석과학
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    • 제37권2호
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    • pp.98-113
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    • 2024
  • The current investigation entails the characterization of five degradation products (DPs) formed under different stress conditions of loteprednol using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In addition, this study developed a stable high-performance liquid chromatography (HPLC) method for evaluating loteprednol along with impurities. The method conditions were meticulously fine-tuned which involved the exploration of the appropriate solvent, pH, flow of the mobile phase, columns, and wavelength. The method conditions were carefully chosen to successfully resolve the impurities of loteprednol and were employed in subsequent validation procedures. The stability profile of loteprednol was exposed to stress degradation experiments conducted under five conditions, and DPs were structurally characterized by employing LC-MS/MS. The chromatographic resolution of loteprednol and its impurities along with DPs was effectively achieved using a Phenomenex Luna 250 mm C18 column using 0.1 % phosphoric acid, methanol, and acetonitrile in 45:25:30 (v/v) pumped isocratically at 0.8 mL/min with 243 nm wavelength. The method produces an accurate fit calibration curve in 50-300 ㎍/mL for loteprednol and LOQ (0.05 ㎍/mL) - 0.30 ㎍/mL for its impurities with acceptable precision, accuracy, and recovery. The stress-induced degradation study revealed the degradation of loteprednol under basic, acidic, and photolytic conditions, resulting in the formation of seven distinct DPs. The efficacy of this method was validated through LC-MS/MS, which allowed for the verification of the chemical structures of the newly generated DPs of loteprednol. This method was appropriate for assessing the impurities of loteprednol and can also be appropriate for structural and quantitative assessment of its degradation products.

Molecular Analysis of CAG Repeats at Five Different Spinocerebellar Ataxia loci: Correlation and Alternative Explanations for Disease Pathogenesis

  • Alluri, Ravindra Varma;Komandur, Sreelatha;Wagheray, Avinash;Chaudhuri, Jaydip Ray;Sitajayalakshmi, Sitajayalakshmi;Meena, Angmuthu Kanikannan;Jabeen, Afshan;Chawda, Kamalesh;Subhash, Kaul;Krishnaveni, Alladi;Hasan, Qurratulain
    • Molecules and Cells
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    • 제24권3호
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    • pp.338-342
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    • 2007
  • Spinocerebellar ataxias (SCAs) are caused by expansion of (CAG)n triplet repeats. These repeats occur as polymorphic forms in general population; however, beyond a threshold size they become pathogenic. The sizes and distributions of repeats at the SCA1, SCA2, SCA3, SCA7 and DRPLA loci were assessed by molecular analysis of 124 unrelated ataxia patients and 44 controls, and the association of larger normal (LN) alleles with disease prevalence was evaluated. Triplet repeat expansions in the disease range were detected in 8% (10/124) of the cases, with the majority having expansion at the SCA1 locus. Normal allele ranges in the cohort studied were similar to the Caucasian and North Indian populations but differed from the Korean and Japanese populations at various loci. The percentage of individuals with LN alleles at the SCA1 and SCA2 loci was higher than reported in Indians, Japanese and Caucasians. LN alleles showed a good correlation with the incidence of SCA1, indicating that SCA1 is the most prevalent ataxia in our population. The majority of cases with clinical symptoms of SCA could not be diagnosed by established CAG repeat criteria, suggesting that there may be an alternative basis for disease pathogenesis: (i) Repeats lower than the normal range may also result in abnormal phenotypes (ii) LN alleles at different loci in the same individual may contribute to symptoms (iii) Exogenous factors may play a role in triggering disease symptoms in individuals with LN alleles (iv) Triplet repeats may reach the disease range in the brain but not in the blood.

DETERMINATION OF SUGARS AND ORGANIC ACIDS IN ORAGE JUICES USING NEAR INFRARED DIFFUSE REFLECTANCE SPECTROSCOPY

  • Tewari, Jagdish;Mehrotra, Ranajana;Gupta, Alka;Varma, S.P.
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1522-1522
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    • 2001
  • Beverages based on fruit juices are among the most popular commercially available drinks. There is an ever-increasing demand for these juices in the market. Orange juice is one of the most common as well as most favorite flavor. The fruit processing industries have a tremendous responsibility of quality control. For quality evaluation estimation of various components of the juice is necessary. Sucrose, glucose, fructose, citric acid and malic acid are the prime components of orange juice. Little information is available on analysis of orange juice. However, conventional and general wet chemistry procedures are currently being used which are no longer desired by the industry owing to the time involved, labor input and harmful chemicals required for each analysis. Need to replace these techniques with new, highly specific and automated sophisticated techniques viz. HPLC and spectroscopy has been realized since long time. Potential of Near Infrared Spectroscopy in quantitative analysis of different components of food samples has also been well established. A rapid, non-destructive and accurate technique based on Near Infrared Spectroscopy for determination of sugars and organic acids in orange juice will be highly useful. The current study is an investigation into the potential of Near Infrared Diffuse Reflectance Spectroscopy for rapid quantitative analysis of sucrose, glucose, fructose citric acid and malic acid in orange juice. All the Near Infrared measurements were peformed on a dispersive NIR spectrophotometer (ELICO 153) in diffuse reflectance mode. The spectral region from 1100 to 2500nm has been explored. The calibration has been performed on synthetic samples that are mixtures of sucrose, glucose, fructose, citric acid and malic acid in different concentration ranges typically encountered real orange juice. These synthetic samples are therefore considered to be representatives of natural juices. All the Near Infrared spectra of synthetic samples were subjected to mathematical analysis using Partial Least Square (PLS) algorithm. After the validation, calibration was applied to commercially available real samples and freshly squeezed natural juice samples. The actual concentrations were compared with those predicted from calibration curve. A good correlation is obtained between actual and predicted values as indicated by correlation coefficient ($R^2$) value, which is close to unity, showing the feasibility of the technique.

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