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BACKGROUND: Theoretical advantages of Turnbull-Cutait pull-through delayed coloanal anastomosis (DCAA) are a reduced risk of anastomotic leak and therefore avoidance of stoma. Gradually abandoned in favor of immediate coloanal anastomosis (ICAA) with diverting stoma, DCAA has regained popularity in recent years in reconstructive surgery for low RC, especially when combined with minimally invasive surgery (MIS). The aim of this study was to perform the first meta-analysis, exploring the safety and outcomes of DCAA compared to ICAA with protective stoma. METHODS: A systematic search of MEDLINE, EMBASE, and CENTRAL and Google Scholar databases was performed for studies published from January 2000 until December 2020. The systematic review and meta-analysis were performed according to the Cochrane Handbook for Systematic Review on Interventions recommendations and Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. RESULTS: Out of 2626 studies screened, 9 were included in the systematic review and 4 studies in the meta-analysis. Outcomes included were postoperative complications, pelvic sepsis and risk of definitive stoma. Considering postoperative complications classified as Clavien-Dindo III, no significant difference existed in the rate of postoperative morbidity between DCAA and ICAA (13% versus 21%; OR 1.17; 95% CI 0.38-3.62; p = 0.78; I2 = 20%). Patients in the DCAA group experienced a lower rate of postoperative pelvic sepsis compared with patients undergoing ICAA with diverting stoma (7% versus 14%; OR 0.37; 95% CI 0.16-0.85; p = 0.02; I2 = 0%). The risk of definitive stoma was comparable between the two groups (2% versus 2% OR 0.77; 95% CI 0.15-3.85; p = 0.75; I2 = 0%). CONCLUSIONS: According to the limited current evidence, DCAA is associated with a significant decrease in pelvic sepsis. Further prospective trials focusing on oncologic and functional outcomes are needed.
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Neoplasias del Recto , Sepsis , Canal Anal/cirugía , Anastomosis Quirúrgica/efectos adversos , Fuga Anastomótica/etiología , Fuga Anastomótica/cirugía , Colon/cirugía , Humanos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Neoplasias del Recto/complicaciones , Neoplasias del Recto/cirugía , Estudios Retrospectivos , Sepsis/etiología , Resultado del TratamientoRESUMEN
BACKGROUND: Several publications and guidelines designate diabetes mellitus (DM) as a coronary artery disease (CAD) risk equivalent. The aim of this investigation was to examine DM cardiac risk equivalence from the perspective of stress SPECT myocardial perfusion imaging (MPI). METHODS AND RESULTS: We examined cardiovascular outcomes (cardiac death or nonfatal MI) of 17,499 patients referred for stress SPECT-MPI. Patients were stratified into four categories: non-DM without CAD, non-DM with CAD, DM without CAD, and DM with CAD, and normal or abnormal perfusion. Cardiac events occurred in 872 (5%), with event-free survival best among non-DM without CAD, worst in DM with CAD, and intermediate in DM without CAD, and non-DM with CAD. After multivariate adjustment, risk remained comparable between DM without CAD and non-DM with CAD [AHR 1.0 (95% CI 0.84-1.28), P =0.74]. Annualized event rates for normal subjects were 1.4% and 1.6% for non-DM with CAD and DM without CAD, respectively (P = 0.48) and 3.5% (P = 0.95) for both abnormal groups. After multivariate adjustment, outcomes were comparable within normal [AHR 1.4 (95% CI 0.98-1.96) P = 0.06] and abnormal [AHR 1.1 (95% CI 0.83-1.50) P = 0.49] MPI. CONCLUSIONS: Diabetic patients without CAD have comparable risk of cardiovascular events as non-diabetic patients with CAD after stratification by MPI results. These findings support diabetes as a CAD equivalent and suggest that MPI provides additional prognostic information in such patients.
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Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Diabetes Mellitus/diagnóstico por imagen , Imagen por Resonancia Magnética , Imagen de Perfusión Miocárdica , Tomografía Computarizada de Emisión de Fotón Único , Anciano , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/mortalidad , Complicaciones de la Diabetes/diagnóstico por imagen , Complicaciones de la Diabetes/mortalidad , Diabetes Mellitus/mortalidad , Femenino , Estudios de Seguimiento , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Imagen Multimodal , Análisis Multivariante , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/mortalidad , Pronóstico , Estudios Prospectivos , Estudios Retrospectivos , RiesgoRESUMEN
BACKGROUND AND AIMS: Pancreatic cancer (PC) is a deadly disease that is most commonly diagnosed at an incurable stage. Different high-risk genetic variants and cancer syndromes increase the lifetime risk of developing PC. This study aims to assess the yield of initial PC screening in patients with high-risk germline mutations. METHODS: Asymptomatic adults underwent PC screening by EUS, magnetic resonance imaging, or CT during a 10-year period and were retrospectively identified. High-risk individuals were defined as carrying germline mutations in BRCA1, BRCA2, p53 (Li-Fraumeni), STK11 (Peutz-Jeghers), MSH2 (Lynch), ATM (ataxia-telangiectasia), or APC (familial adenomatous polyposis). Patients without germline mutations were excluded. RESULTS: In total, 86 patients met the study criteria. The median age was 48.5 years (interquartile range, 40-58), 79.1% (68) were women, and 43.0% (37) had a family history of PC. The genetic mutations were BRCA2 (50, 58.1%), BRCA1 (14, 16.3%), p53 (12, 14.0%), STK11 (5, 5.8%), MSH2 (3, 3.5%), ATM (1, 1.2%), and APC (1, 1.2%). Screening detected a pancreatic abnormality (PA) in 26.7% (23/86), including cysts (11, 47.8%), hyperechoic strands and foci (10, 43.5%), and mild pancreatic duct dilation (2, 8.7%). Patients older than 60 years were more likely to have a PA detected (P = .043). EUS detected more PAs than magnetic resonance imaging or CT. No cases of PC were diagnosed by screening or during follow-up (median, 29.8 months; interquartile range, 21.7-43.5). CONCLUSIONS: Unless indicated otherwise by family or personal history, PC screening under the age of 50 is low yield. Linear EUS may be the preferred modality for initial PC screening.
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Páncreas/diagnóstico por imagen , Quiste Pancreático/diagnóstico por imagen , Neoplasias Pancreáticas/diagnóstico por imagen , Quinasas de la Proteína-Quinasa Activada por el AMP , Poliposis Adenomatosa del Colon/complicaciones , Poliposis Adenomatosa del Colon/genética , Proteína de la Poliposis Adenomatosa del Colon/genética , Adulto , Ataxia Telangiectasia/complicaciones , Ataxia Telangiectasia/genética , Proteínas de la Ataxia Telangiectasia Mutada/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias Colorrectales Hereditarias sin Poliposis/complicaciones , Neoplasias Colorrectales Hereditarias sin Poliposis/genética , Detección Precoz del Cáncer , Endosonografía , Femenino , Estudios de Seguimiento , Predisposición Genética a la Enfermedad , Mutación de Línea Germinal , Humanos , Síndrome de Li-Fraumeni/complicaciones , Síndrome de Li-Fraumeni/genética , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Proteína 2 Homóloga a MutS/genética , Síndromes Neoplásicos Hereditarios/complicaciones , Síndromes Neoplásicos Hereditarios/genética , Neoplasias Pancreáticas/etiología , Neoplasias Pancreáticas/genética , Síndrome de Peutz-Jeghers/complicaciones , Síndrome de Peutz-Jeghers/genética , Proteínas Serina-Treonina Quinasas/genética , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Proteína p53 Supresora de Tumor/genéticaRESUMEN
An increasing percentage of ageing population requires 30-year survivability of orthopedic devices that is not possible with the current bioinert materials, having a maximum of 15-year survivability. To satisfy this growing need, a shift is needed from replacement of tissues to regeneration of tissues. This is highly possible through the use of silica-bioactive glasses. However, a failure of implant can occur due to infections even by using such materials. Advances in using silver for antibacterial applications have been commercialized. However, higher concentrations of silver also lead to toxic effects. In this study, nanoBioglass 45S5 (NBG) and Ag-NBG were synthesized by using sol-gel method followed by solution-phase method, respectively. The bioactive crystals such as Na2Ca2Si3O9, CaCO3, and AgPO3, very much needed in the field of bone tissue engineering and in antibacterial strategies, were obtained in the NBG Matrix. The morphological investigation of NBG with 1 mM Ag+ concentrations shows the nanospikes arrangement of size 30-40 nm with spherical porous structure of size 10-20 nm, which supports the formation of collagen molecular fibrils on the surface of NBG matrices and enhances osseointegration. Both gram-positive and gram-negative strains show higher antibacterial activity for nanoBioglass with 1 mM Ag+ concentration.
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Antibacterianos/química , Materiales Biocompatibles/química , Vidrio/química , Nanopartículas del Metal/química , Plata/química , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Materiales Biocompatibles/farmacología , Carbonato de Calcio , Viabilidad Microbiana/efectos de los fármacos , Transición de Fase , Plata/farmacología , Análisis EspectralRESUMEN
Candida albicans and Candida dubliniensis are diploid, predominantly asexual human-pathogenic yeasts. In this study, we constructed tetraploid (4n) strains of C. albicans of the same or different lineages by spheroplast fusion. Induction of chromosome loss in the tetraploid C. albicans generated diploid or near-diploid progeny strains but did not produce any haploid progeny. We also constructed stable heterotetraploid somatic hybrid strains (2n + 2n) of C. albicans and C. dubliniensis by spheroplast fusion. Heterodiploid (n + n) progeny hybrids were obtained after inducing chromosome loss in a stable heterotetraploid hybrid. To identify a subset of hybrid heterodiploid progeny strains carrying at least one copy of all chromosomes of both species, unique centromere sequences of various chromosomes of each species were used as markers in PCR analysis. The reduction of chromosome content was confirmed by a comparative genome hybridization (CGH) assay. The hybrid strains were found to be stably propagated. Chromatin immunoprecipitation (ChIP) assays with antibodies against centromere-specific histones (C. albicans Cse4/C. dubliniensis Cse4) revealed that the centromere identity of chromosomes of each species is maintained in the hybrid genomes of the heterotetraploid and heterodiploid strains. Thus, our results suggest that the diploid genome content is not obligatory for the survival of either C. albicans or C. dubliniensis. In keeping with the recent discovery of the existence of haploid C. albicans strains, the heterodiploid strains of our study can be excellent tools for further species-specific genome elimination, yielding true haploid progeny of C. albicans or C. dubliniensis in future.
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Candida albicans/genética , Proteínas Cromosómicas no Histona/genética , Diploidia , Proteínas Fúngicas/genética , Haploidia , Secuencia de Bases , Candida albicans/crecimiento & desarrollo , Candida albicans/patogenicidad , Centrómero/genética , Quimera/genética , Hibridación Genómica Comparativa , Genoma Fúngico , Humanos , Esferoplastos/genética , Esferoplastos/crecimiento & desarrolloRESUMEN
Mechanisms regulating gene expression in malaria parasites are not well understood. Little is known about how the parasite regulates its gene expression during transition from one developmental stage to another and in response to various environmental conditions. Parasites in a diseased host face environments which differ from the static, well adapted in vitro conditions. Parasites thus need to adapt quickly and effectively to these conditions by establishing transcriptional states which are best suited for better survival. With the discovery of natural antisense transcripts (NATs) in this parasite and considering the various proposed mechanisms by which NATs might regulate gene expression, it has been speculated that these might be playing a critical role in gene regulation. We report here the diversity of NATs in this parasite, using isolates taken directly from patients with differing clinical symptoms caused by malaria infection. Using a custom designed strand specific whole genome microarray, a total of 797 NATs targeted against annotated loci have been detected. Out of these, 545 NATs are unique to this study. The majority of NATs were positively correlated with the expression pattern of the sense transcript. However, 96 genes showed a change in sense/antisense ratio on comparison between uncomplicated and complicated disease conditions. The antisense transcripts map to a broad range of biochemical/metabolic pathways, especially pathways pertaining to the central carbon metabolism and stress related pathways. Our data strongly suggests that a large group of NATs detected here are unannotated transcription units antisense to annotated gene models. The results reveal a previously unknown set of NATs that prevails in this parasite, their differential regulation in disease conditions and mapping to functionally well annotated genes. The results detailed here call for studies to deduce the possible mechanism of action of NATs, which would further help in understanding the in vivo pathological adaptations of these parasites.
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Regulación del Desarrollo de la Expresión Génica/genética , Malaria Falciparum/parasitología , Plasmodium falciparum/genética , ARN sin Sentido/análisis , Adolescente , Adulto , Mapeo Cromosómico , Femenino , Ontología de Genes , Genoma de Protozoos , Estudio de Asociación del Genoma Completo , Técnicas de Genotipaje , Humanos , Malaria Falciparum/complicaciones , Masculino , Persona de Mediana Edad , Anotación de Secuencia Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Plasmodium falciparum/clasificación , Plasmodium falciparum/aislamiento & purificación , Plasmodium falciparum/metabolismo , ARN sin Sentido/sangre , ARN Protozoario/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transcripción Genética , Adulto JovenRESUMEN
This research study is primarily centred around calcination temperature and time influence on phase formation in bioactive glasses (BGs). In the present study, BG with a nominal composition of 45S5 was synthesized through the sol-gel process. The developed BGs then underwent heat treatment for various sintering durations and temperatures. X-ray diffraction (XRD) patterns of the BGs reveals that the sintering process led to the crystallization of both devitrite (Na2Ca3Si6O16) and combeite (Na2Ca2Si3O9) phases. The field emission scanning electron microscopy study divulges morphological alterations, from sheet-like to rod-like structures to eventually transforming into spherical and sheet-like structures. The surface area and Type-IV mesoporous porosity were validated through Brunauer Emmett Teller analysis, highlighting a notable increase in pore volume and mechanical strength at a lower sintering temperature.In vitroapatite formation was carried out in Hank's balance salt in order to evaluate the bioactivity of the glass. After 7 d of immersion in simulated body fluid (SBF), XRD patterns and scanning electron microscopy micrographs results showed that formation of hydroxyapatite layer on the surface of the BGs. The BG compatibility with erythrocytes (red blood cells) was also studied, and the results revealed that there was only a low 2% lysis, showing good hemocompatibility. The drug loading and release behaviour of the BGs was studied in thein vitroanalysis. The findings showed a high drug encapsulation effectiveness of up to 90% and continuous drug release from the BGs for 24 h. The materials biocompatibility was unambiguously confirmed by cytocompatibility and proliferation studies. This study provides compelling evidence for the exceptional efficacy and promise of the distinct 45S5 BGs in advancing the field of regenerative medicine.
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Materiales Biocompatibles , Durapatita , Materiales Biocompatibles/química , Durapatita/química , Cristalización/métodos , Microscopía Electrónica de Rastreo , Vidrio/química , Cerámica/químicaRESUMEN
Differentiation of latent tuberculosis infection (LTBI) from active disease is one of the crucial elements in the control of tuberculosis. Earlier in Indian population which is tuberculosis endemic, we identified that 10 Mycobacterium tuberculosis secreted protein fractions, induced IFN-γ response only in healthy contacts of TB patients (HCs) and not in tuberculosis patients (TB). These fractions were termed as "Contact Specific Fractions" ("CS" fractions) and found useful for differentiating HC from TB. Proteomic analysis revealed that "CS" fractions have 16 different proteins, of which three were novel T cell antigens. Using these "CS" fractions as stimulants, earlier IFN-γ, TNF-α and IL-4 cytokine responses were studied. In the present study, in order to identify the other useful cytokine biomarkers that were differentially expressed between HC and TB, Cytokine/chemokine response to "CS" fractions were analyzed using multiplex cytokine assay system. This preliminary investigation in our tuberculosis endemic population showed six cytokine (G-CSF, IL-6, IL-7, IL-8, IL-9, and PDGF) and one receptor antagonist (IL-1Ra) that were differentially expressed between HC and TB, for the first time. Especially IL-6 and PDGF were more promising biomarkers. IL-6 measurement identified seven as HC out of 10 HC analyzed. The measurement of PDGF identified eight as TB out of 10TB tested. Studies are underway to further validate these biomarkers for the differentiation of LTBI from active tuberculosis.
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Quimiocinas/sangre , Enfermedades Endémicas , Tuberculosis Latente/diagnóstico , Adulto , Biomarcadores/sangre , Quimiocinas/metabolismo , Femenino , Factor Estimulante de Colonias de Granulocitos/sangre , Factor Estimulante de Colonias de Granulocitos/metabolismo , Humanos , India/epidemiología , Proteína Antagonista del Receptor de Interleucina 1/sangre , Proteína Antagonista del Receptor de Interleucina 1/metabolismo , Tuberculosis Latente/sangre , Tuberculosis Latente/inmunología , Masculino , Persona de Mediana Edad , Factor de Crecimiento Derivado de Plaquetas/metabolismo , Proteómica , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Pancreas plays an important role in maintaining the glucose homeostasis. The deterioration of ß-cells in the pancreas is a crucial factor in the progression of diabetes mellitus; therefore, the restoration of ß-cell mass and its function is of vital importance for effective therapeutic strategies. The precise mechanism for increase in functional ß-cell mass is still unknown. This review focuses on the importance of certain genes which are involved in the rejuvenation of pancreas. These genes are divided according to their functions into three categories: participate either in proliferation (mitotic division of differentiated ß-cells), neogenesis/transdifferentiation (development from precursor cells) or inhibition of ß-cell apoptosis (programmed cell death). The rate of ß-cell rejuvenation is the balance among the rates of ß-cell proliferation, neogenesis and apoptosis. Understanding these genes and their pathways may lead to the discovery of new drugs, target based gene delivery and development of safer antidiabetic drugs.
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Apoptosis/genética , Glucosa/metabolismo , Homeostasis/genética , Islotes Pancreáticos/citología , Proliferación Celular , Transdiferenciación Celular/genética , Glucosa/genética , Humanos , Islotes Pancreáticos/fisiología , Rejuvenecimiento/fisiologíaRESUMEN
BACKGROUND: Phyto-remedies for diabetic control are popular among patients with Type II Diabetes mellitus (DM), in addition to other diabetic control measures. A number of plant species are known to possess diabetic control properties. Costus pictus D. Don is popularly known as "Insulin Plant" in Southern India whose leaves have been reported to increase insulin pools in blood plasma. Next Generation Sequencing is employed as a powerful tool for identifying molecular signatures in the transcriptome related to physiological functions of plant tissues. We sequenced the leaf transcriptome of C. pictus using Illumina reversible dye terminator sequencing technology and used combination of bioinformatics tools for identifying transcripts related to anti-diabetic properties of C. pictus. RESULTS: A total of 55,006 transcripts were identified, of which 69.15% transcripts could be annotated. We identified transcripts related to pathways of bixin biosynthesis and geraniol and geranial biosynthesis as major transcripts from the class of isoprenoid secondary metabolites and validated the presence of putative norbixin methyltransferase, a precursor of Bixin. The transcripts encoding these terpenoids are known to be Peroxisome Proliferator-Activated Receptor (PPAR) agonists and anti-glycation agents. Sequential extraction and High Performance Liquid Chromatography (HPLC) confirmed the presence of bixin in C. pictus methanolic extracts. Another significant transcript identified in relation to anti-diabetic, anti-obesity and immuno-modulation is of Abscisic Acid biosynthetic pathway. We also report many other transcripts for the biosynthesis of antitumor, anti-oxidant and antimicrobial metabolites of C. pictus leaves. CONCLUSION: Solid molecular signatures (transcripts related to bixin, abscisic acid, and geranial and geraniol biosynthesis) for the anti-diabetic properties of C. pictus leaves and vital clues related to the other phytochemical functions like antitumor, anti-oxidant, immuno-modulatory, anti-microbial and anti-malarial properties through the secondary metabolite pathway annotations are reported. The data provided will be of immense help to researchers working in the treatment of DM using herbal therapies.
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Costus/genética , Genes de Plantas , Hipoglucemiantes/metabolismo , Hojas de la Planta/genética , Transcriptoma , Ácido Abscísico/metabolismo , Monoterpenos Acíclicos , Secuencia de Bases , Carotenoides/metabolismo , Cromatografía Líquida de Alta Presión , Biología Computacional , Costus/metabolismo , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Metiltransferasas/metabolismo , Anotación de Secuencia Molecular , Datos de Secuencia Molecular , Monoterpenos/metabolismo , Fitoterapia , Extractos Vegetales/química , Hojas de la Planta/metabolismo , Análisis de Secuencia de ADN , Terpenos/metabolismoRESUMEN
BACKGROUND: The pattern-forming bacterium Paenibacillus vortex is notable for its advanced social behavior, which is reflected in development of colonies with highly intricate architectures. Prior to this study, only two other Paenibacillus species (Paenibacillus sp. JDR-2 and Paenibacillus larvae) have been sequenced. However, no genomic data is available on the Paenibacillus species with pattern-forming and complex social motility. Here we report the de novo genome sequence of this Gram-positive, soil-dwelling, sporulating bacterium. RESULTS: The complete P. vortex genome was sequenced by a hybrid approach using 454 Life Sciences and Illumina, achieving a total of 289× coverage, with 99.8% sequence identity between the two methods. The sequencing results were validated using a custom designed Agilent microarray expression chip which represented the coding and the non-coding regions. Analysis of the P. vortex genome revealed 6,437 open reading frames (ORFs) and 73 non-coding RNA genes. Comparative genomic analysis with 500 complete bacterial genomes revealed exceptionally high number of two-component system (TCS) genes, transcription factors (TFs), transport and defense related genes. Additionally, we have identified genes involved in the production of antimicrobial compounds and extracellular degrading enzymes. CONCLUSIONS: These findings suggest that P. vortex has advanced faculties to perceive and react to a wide range of signaling molecules and environmental conditions, which could be associated with its ability to reconfigure and replicate complex colony architectures. Additionally, P. vortex is likely to serve as a rich source of genes important for agricultural, medical and industrial applications and it has the potential to advance the study of social microbiology within Gram-positive bacteria.
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Ambiente , Genoma Bacteriano/genética , Paenibacillus/crecimiento & desarrollo , Paenibacillus/genética , Análisis de Secuencia de ADN , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Emparejamiento Base/genética , Secuencia de Bases , Quimiotaxis/genética , Recuento de Colonia Microbiana , Flagelos/genética , Flagelos/ultraestructura , Genes Bacterianos/genética , Complejos Multienzimáticos/genética , Familia de Multigenes , Análisis de Secuencia por Matrices de Oligonucleótidos , Paenibacillus/citología , Paenibacillus/ultraestructura , Filogenia , Secuencias Repetitivas de Ácidos Nucleicos/genética , Reproducibilidad de los ResultadosRESUMEN
A novel organic nonlinear optical (NLO) material, l-alaninium succinate, was synthesized by the standard method. The synthesized material was purified by repeated recrystallization. Single crystals were grown by slow evaporation technique using water as solvent. The grown crystals were characterized by FT-IR, FT-NMR and UV-vis-NIR techniques. The second harmonic generation (SHG) from the material was confirmed using Nd:YAG laser which shows that LAS has 23% SHG efficiency of that of the standard KDP. The UV-vis-NIR transmittance was recorded in the range from 190 to 1100nm. In this study, the lower cut-off is shifted towards UV region (190nm) which shows that LAS has good transmittance in region from 190 to 1100nm and it makes LAS for SHG. Functional groups present in the grown crystal were identified using FT-IR spectrum which gives confirmation of NH(3)(+) ion in LAS. The chemical structure of l-alaninium succinate was established by FT-NMR technique.
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Alanina/química , Succinatos/química , Cristalización , Óptica y Fotónica , Análisis Espectral/métodosRESUMEN
The process of setting a standard when pass/fail decisions have to be made inevitably involves judgment about the point on the test score scale where performance is deemed to be adequate for the purpose for which the examination is set. As with any process which involves human judgment, setting this standard is likely to include a certain degree of error, which may result in some false positive and false negative decisions. The customary practice of maintaining a constant point on the test score scale at which pass/fail separations are made cannot be justified, as examinations vary in difficulty. The aim of standard setting procedures is to minimize such errors while accounting for the varying difficulty of examinations. A standard may be norm-referenced, where it is dependent on the performance of the particular group of examinees, or criterion-referenced, where it is based on predetermined criteria, irrespective of examinee performance. Where certification of competence is the primary purpose of an examination, the latter is preferred as the decision to be made is whether an individual is competent to practise rather than competent compared to peers. Several methods of standard setting have been used, some of which are based solely on predetermined criteria, while others compromise between norm- and criterion-referenced standards. This guide examines the more commonly used methods of standard setting, illustrates the procedure used in each with the help of an example, and discusses the advantages and disadvantages associated with the use of each. The common errors made by judges in the standard setting process are pointed out and the manner in which judges should be selected, trained and instructed emphasized. A method used for equating similar tests set at different times with the intention of maintaining standards from one examination to the next is illustrated with an example. Finally, the guide proposes a practical method for arriving at a pre-determined standard by the proportionate selection of test-items of known relative difficulties in relation to minimally competent examinees.
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Educación Médica/normas , Evaluación Educacional/métodos , Evaluación Educacional/normas , Juicio , Competencia Profesional , Humanos , Modelos Educacionales , Reproducibilidad de los ResultadosRESUMEN
A novel organic non-linear optical organic single crystal of 4-phenylpyridinium hydrogen squarate (4PHS) has been synthesized and successfully grown from aqueous solutions by slow evaporation solution growth method. In the present investigation the title compound has been synthesized by taking equimolar quantity of 4-phenylpyridine and squaric acid and mixed thoroughly using double distilled water as the solvent. The prepared concentrated solution was placed in an undisturbed condition, and then the solution was periodically inspected. The good quality single crystals have been harvested in a time span of 3 weeks. Then the grown crystal was characterized as single crystal XRD, differential thermal analysis, thermogravimetric analysis, FTIR, UV-vis-NIR, SHG, (1)H NMR and (13)C NMR analyses, respectively. The observed results from the characterization analyses show its suitability for NLO applications when compared with some of the existing organic crystals. The relative second harmonic generation of this grown crystal was found to be five times higher than that of KDP crystal. The UV cut-off wavelength and decomposition temperature of this grown crystal were also comparatively better. (1)H NMR and (13)C NMR spectroscopic studies were employed to elucidate the structure of the grown specimen.
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Ciclobutanos/química , Ciclobutanos/síntesis química , Óptica y Fotónica , Compuestos de Piridinio/química , Compuestos de Piridinio/síntesis química , Análisis Diferencial Térmico , Espectroscopía de Resonancia Magnética , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Termogravimetría , Vibración , Difracción de Rayos XRESUMEN
Bartonella is a genetically diverse group of vector-borne bacteria. Over 40 species have been characterized to date, mainly from mammalian reservoirs and arthropod vectors. Rodent reservoirs harbor one of the largest Bartonella diversity described to date, and novel species and genetic variants are continuously identified from these hosts. Yet, it is still unknown if this significant genetic diversity stems from adaptation to different niches or from intrinsic high mutation rates. Here, we explored the vertical occurrence of spontaneous genomic alterations in 18 lines derived from two rodent-associated Bartonella elizabethae-like strains, evolved in nonselective agar plates under conditions mimicking their vector- and mammalian-associated temperatures, and the transmission cycles between them (i.e., 26 °C, 37 °C, and alterations between the two), using mutation accumulation experiments. After â¼1,000 generations, evolved genomes revealed few point mutations (average of one-point mutation per line), evidencing conserved single-nucleotide mutation rates. Interestingly, three large structural genomic changes (two large deletions and an inversion) were identified over all lines, associated with prophages and surface adhesin genes. Particularly, a prophage, deleted during constant propagation at 37 °C, was associated with an increased autonomous replication at 26 °C (the flea-associated temperature). Complementary molecular analyses of wild strains, isolated from desert rodents and their fleas, further supported the occurrence of structural genomic variations and prophage-associated deletions in nature. Our findings suggest that structural genomic changes represent an effective intrinsic mechanism to generate diversity in slow-growing bacteria and emphasize the role of prophages as promoters of diversity in nature.
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Bartonella/genética , Evolución Biológica , Variación Estructural del Genoma , Profagos/fisiología , Bartonella/virología , Genoma Bacteriano , Familia de MultigenesRESUMEN
A case of spontaneous biceps tendon rupture in a physician during therapy with the combination of simvastatin and ezetimibe (Vytorin) is reported. Rechallenge produced tendinopathy in the contralateral biceps tendon that abated with drug discontinuation. Tendon rupture generally occurs in injured tendons. Physiological repair of an injured tendon requires degradation and remodeling of the extracellular matrix through matrix metalloproteinases (MMPs). Statins are known to inhibit MMPs. It was hypothesized that statins may increase the risk of tendon rupture by altering MMP activity. In conclusion, statins may increase the risk of tendon rupture by altering MMP activity.
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Anticolesterolemiantes/efectos adversos , Azetidinas/efectos adversos , Simvastatina/efectos adversos , Traumatismos de los Tendones/inducido químicamente , Ezetimiba , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Imagen por Resonancia Magnética , Masculino , Metaloproteasas/metabolismo , Persona de Mediana Edad , Traumatismos de los Tendones/diagnóstico , Traumatismos de los Tendones/metabolismo , Tendones/efectos de los fármacosRESUMEN
The complete mitochondrial genome of Himalayan bee Apis laboriosa, from Mizoram, India, has been sequenced using Illumina NextSeq500 platform and analysed. The mitogenome was assembled and found to be 15 266 bp in length and the gene arrangement is similar to other honey bee species. The A. laboriosa mitogenome comprises of 13 protein-coding genes (PCGs), 22 tRNAs, 2 rRNAs and an A + T-rich region of 346 bp. Based on the concatenated PCGs, in the phylogenetic tree, A. laboriosa is placed as a sister group along with the cavity nesting honey bees. The present study reports the first complete mitochondrial genome sequence of A. laboriosa, which will enhance our knowledge on Apinae mitogenomes and phylogeny.
Asunto(s)
Abejas/genética , Genoma Mitocondrial , Animales , Orden Génico , Genes de Insecto , Filogenia , ARN Ribosómico/genética , ARN de Transferencia/genética , Secuenciación Completa del GenomaRESUMEN
The complete mitogenome of Apis cerana cerana (Hymenoptera: Apidae: Apinae) was sequenced using Illumina NextSeq500 platform and found to be 15 831 bp long. The mitogenome contains 37 genes (13 PCGs, 22 tRNAs, and 2 rRNAs) and a control region. The base composition is biased towards A-T (83.9%). The control region is 498 bp long with polyT stretch and poly [TA (A)]n-like stretch. The phylogenetic tree constructed using concatenated PCGs showed that A. cerana cerana clustered with other cavity nesting Apis species.
Asunto(s)
Abejas/genética , Genes de Insecto , Genes Mitocondriales , Genoma Mitocondrial , Animales , Composición de Base , Abejas/clasificación , Evolución Molecular , Filogenia , Análisis de Secuencia de ADNRESUMEN
Malarial parasite P. falciparum, an apicomplexan protozoan has a 23.3 MB nuclear genome and encodes ~ 5600 transcripts. The genetic diversity of the parasite within and across geographical zones is a challenge to gene expression studies which are essential for understanding of disease process, outcome and developing markers for diagnostics and prognostics. Here, we describe the strategy involved in designing a custom P. falciparum 15K array using the Agilent platform and Genotypic's Right Design methodology to study the transcriptome of Indian field isolates for which genome sequence information is limited. The array contains probes representing genome sequences of two distinct geographical isolates (i.e. 3D7 and HB3) and sub-telomeric var gene sequences of a third isolate (IT4) known to adhere in culture condition. Probes in the array have been selected based on their efficiency to detect transcripts through a 244K array experimentation. Array performance for the 15K array, was evaluated and validated using RNA materials from P. falciparum clinical isolates. A large percentage (91%) of the represented transcripts was detected from Indian P. falciparum patient isolates. Replicated probes and multiple probes representing the same gene showed perfect correlation between them suggesting good probe performance. Additional transcripts could be detected due to inclusion of unique probes representing HB3 strain transcripts. Variant surface antigen (VSA) transcripts were detected by optimized probes representing the VSA genes of three geographically distinct strains. The 15K cross strain P. falciparum array has shown good efficiency in detecting transcripts from P. falciparum parasite samples isolated from patients. The low parasite loads and presence of host RNA makes arrays a preferred platform for gene expression studies over RNA-Seq.