Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Transl Med ; 21(1): 703, 2023 10 09.
Artículo en Inglés | MEDLINE | ID: mdl-37814319

RESUMEN

Bone marrow fibrosis represents an important structural change in the marrow that interferes with some of its normal functions. The aetiopathogenesis of fibrosis is not well established except in its primary form. The present review consolidates current understanding of marrow fibrosis. We searched PubMed without time restriction using key words: bone marrow and fibrosis as the main stem against the terms: growth factors, cytokines and chemokines, morphology, megakaryocytes and platelets, myeloproliferative disorders, myelodysplastic syndrome, collagen biosynthesis, mesenchymal stem cells, vitamins and minerals and hormones, and mechanism of tissue fibrosis. Tissue marrow fibrosis-related papers were short listed and analysed for the review. It emerged that bone marrow fibrosis is the outcome of complex interactions between growth factors, cytokines, chemokines and hormones together with their facilitators and inhibitors. Fibrogenesis is initiated by mobilisation of special immunophenotypic subsets of mesenchymal stem cells in the marrow that transform into fibroblasts. Fibrogenic stimuli may arise from neoplastic haemopoietic or non-hematopoietic cells, as well as immune cells involved in infections and inflammatory conditions. Autoimmunity is involved in a small subset of patients with marrow fibrosis. Megakaryocytes and platelets are either directly involved or are important intermediaries in stimulating mesenchymal stem cells. MMPs, TIMPs, TGF-ß, PDGRF, and basic FGF and CRCXL4 chemokines are involved in these processes. Genetic and epigenetic changes underlie many of these conditions.


Asunto(s)
Médula Ósea , Mielofibrosis Primaria , Humanos , Médula Ósea/metabolismo , Mielofibrosis Primaria/etiología , Mielofibrosis Primaria/metabolismo , Mielofibrosis Primaria/patología , Citocinas/metabolismo , Fibrosis , Quimiocinas/metabolismo , Hormonas
2.
Hemoglobin ; 39(6): 380-3, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25970198

RESUMEN

The thalassemias are among the most common monogenic diseases worldwide, a national health burden in India. There are estimated 7500-12,000 babies born with ß-thalassemia major (ß-TM) every year in this country. Couples who are at-risk of having children with hemoglobin (Hb) disorders desired to have the option of avoiding the birth of an affected child by prenatal diagnosis (PND). Thus, the prenatal women are a highly important target group for carrier screening and preventing the birth of thalassemic children in the country. The present study was conducted among 20,883 pregnant women, irrespective of gravida and duration of pregnancy, from the prenatal clinic of Nilratan Sarkar (NRS) Medical College & Hospital, Kolkata, West Bengal, India, from February 2009 to November 2012. Thalassemia carrier status was assessed by high performance liquid chromatography (HPLC) along with red blood cell (RBC) indices. Husbands of all thalassemia carrier women were advised and persuaded to undergo screening for hemoglobinopathies. The couples were counseled to undergo PND if both of them were detected to be thalassemia carriers. The data were statistically analyzed to evaluate the efficacy of this procedure.


Asunto(s)
Países en Desarrollo , Hemoglobinopatías/diagnóstico , Diagnóstico Prenatal , Adolescente , Adulto , Índices de Eritrocitos , Femenino , Edad Gestacional , Hemoglobinopatías/epidemiología , Heterocigoto , Humanos , Masculino , Fenotipo , Embarazo , Diagnóstico Prenatal/métodos , Adulto Joven
3.
Hemoglobin ; 38(4): 252-7, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25023086

RESUMEN

Although iron deficiency anemia is very common in India, systematic large studies on the prevalence and hematological consequences of iron deficiency among carriers of ß-thalassemia (ß-thal) and other hemoglobinopathies are lacking. A multi center project was undertaken to screen college/university students and pregnant women for iron deficiency anemia and various hemoglobinopathies. Fifty-six thousand, seven hundred and seventy-two subjects from six states, Maharashtra, Gujarat, Karnataka, West Bengal, Assam and Punjab, were studied. Iron deficiency anemia was evaluated by measuring zinc protoporphyrin (ZPP) and hemoglobin (Hb) levels, while ß-thal and other hemoglobinopathies were detected by measuring the red cell indices and by Hb analysis using high performance liquid chromatography (HPLC). College boys (2.2%), college girls (14.3%) and antenatal women (27.0%) without any hemoglobinopathies had iron deficiency anemia. Among the ß-thal carriers, the prevalence of iron deficiency anemia was 17.3% in college boys, 38.1% in college girls and 55.9% in pregnant women, while in the Hb E [ß26(B8)Glu→Lys; HBB: c.79G>A] carriers, it was 7.3% in college boys, 25.4% in college girls and 78.0% in antenatal women. In individuals with Hb E disease, the prevalence of iron deficiency anemia varied from 31.2-77.3% in the three groups. A significant reduction in Hb levels was seen when iron deficiency anemia was associated with hemoglobinopathies. However, the Hb A2 levels in ß-thal carriers were not greatly reduced in the presence of iron deficiency anemia.


Asunto(s)
Anemia Ferropénica/complicaciones , Anemia Ferropénica/epidemiología , Hemoglobinopatías/complicaciones , Hemoglobinopatías/epidemiología , Estudiantes , Universidades , Adolescente , Adulto , Anemia Ferropénica/diagnóstico , Femenino , Geografía Médica , Hemoglobinopatías/diagnóstico , Humanos , India/epidemiología , Masculino , Embarazo , Prevalencia , Vigilancia en Salud Pública , Adulto Joven
4.
Indian J Hum Genet ; 20(2): 101-19, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25400338

RESUMEN

The ß-thalassemias and sickle cell disorders are a major health burden in India. Diagnosis and management of these disorders both in adults and in newborns using appropriate approaches and uniform technology are important in different regions of a vast and diverse country as India. In view of a National Thalassemia Control Program to be launched soon, a need was felt for guidelines on whom to screen, cost-effective technologies that are to be used as well as for establishing prenatal diagnosis programs in regional centers. Newborn screening for sickle cell disorders is in its infancy in India and uniform approaches need to be followed. Also, included are guidelines for monitoring and managing patients who are now growing older and need comprehensive care as well as management of complications of the disease.

5.
Radiat Prot Dosimetry ; 200(11-12): 979-982, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39016477

RESUMEN

Determination of uranium isotopes in ground water plays a key role in assessment of geochemical condition of ground water and for estimating ingestion dose received by the general public because of uranium intake through drinking water. An attempt has been made in the present study to estimate isotopic composition and activity ratios (AR) of uranium isotopes by analysing the ground water samples using alpha spectrometry. Associated age-dependent ingestion dose was also calculated for the public of different age groups. 238U, 235U and 234U activity concentration was found to vary in the ranges of 5.85 ± 1.19 to 76.67 ± 4.16, < 0.90 to 3.15 ± 0.84 and 6.52 ± 1.25 to 107.02 ± 4.92 mBq/L, respectively. 235U/238U AR varies from 0.038 to 0.068 with an average of 0.047 which is close to 0.046 implies that uranium in the ground water is from natural origin. Uranium concentration was found to vary in the range of 0.47 ± 0.10 µg/L to 6.20 ± 0.34 µg/L with a mean value of 3.01 ± 0.23 µg/L, which is much lower than national as well as international recommendation value. Annual ingestion dose to the public of all age groups for uranium intake through drinking water ranges from 0.60 ± 0.11 to 19.50 ± 1.03 µSv/y.


Asunto(s)
Dosis de Radiación , Monitoreo de Radiación , Uranio , Contaminantes Radiactivos del Agua , Uranio/análisis , Contaminantes Radiactivos del Agua/análisis , Humanos , Monitoreo de Radiación/métodos , Agua Potable/análisis , Agua Subterránea/análisis , Niño , Adulto , Factores de Edad , Partículas alfa , Análisis Espectral/métodos , Adolescente , Preescolar , Adulto Joven
6.
Radiat Prot Dosimetry ; 200(11-12): 1101-1107, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39016491

RESUMEN

This paper presents the concentration of uranium in 67 groundwater samples of Chamarajanagar district, Karnataka, India, estimated using an LED fluorimeter. The age-dependent ingestion dose to the population of the district is also studied. The concentration of uranium in groundwater varied from 0.20 to 57.50 µg L-1 with an average of 4.40 µg L-1. The annual ingestion dose due to uranium varies from 0.18 to 142.68 µSv y-1, with an average of 7.11 µSv y-1. The ingestion dose received by the population in the study area is less than the recommended level of 100 µSv y-1 by the World Health Organization (2011).


Asunto(s)
Agua Subterránea , Dosis de Radiación , Monitoreo de Radiación , Uranio , Contaminantes Radiactivos del Agua , Uranio/análisis , Agua Subterránea/análisis , India , Humanos , Contaminantes Radiactivos del Agua/análisis , Monitoreo de Radiación/métodos
7.
Biometrics ; 69(4): 925-36, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24289144

RESUMEN

Case-crossover designs are widely used to study short-term exposure effects on the risk of acute adverse health events. While the frequentist literature on this topic is vast, there is no Bayesian work in this general area. The contribution of this paper is twofold. First, the paper establishes Bayesian equivalence results that require characterization of the set of priors under which the posterior distributions of the risk ratio parameters based on a case-crossover and time-series analysis are identical. Second, the paper studies inferential issues under case-crossover designs in a Bayesian framework. Traditionally, a conditional logistic regression is used for inference on risk-ratio parameters in case-crossover studies. We consider instead a more general full likelihood-based approach which makes less restrictive assumptions on the risk functions. Formulation of a full likelihood leads to growth in the number of parameters proportional to the sample size. We propose a semi-parametric Bayesian approach using a Dirichlet process prior to handle the random nuisance parameters that appear in a full likelihood formulation. We carry out a simulation study to compare the Bayesian methods based on full and conditional likelihood with the standard frequentist approaches for case-crossover and time-series analysis. The proposed methods are illustrated through the Detroit Asthma Morbidity, Air Quality and Traffic study, which examines the association between acute asthma risk and ambient air pollutant concentrations.


Asunto(s)
Contaminación del Aire/estadística & datos numéricos , Asma/epidemiología , Teorema de Bayes , Estudios Cruzados , Interpretación Estadística de Datos , Modelos Estadísticos , Reconocimiento de Normas Patrones Automatizadas/métodos , Causalidad , Simulación por Computador , Humanos , Funciones de Verosimilitud , Prevalencia , Proyectos de Investigación , Medición de Riesgo/métodos
8.
Ann Hum Genet ; 76(1): 33-41, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22118420

RESUMEN

Variants in the UGT1A1 gene and its promoter are known to determine levels of unconjugated bilirubin (UCB), but do not explain all cases of unconjugated hyperbilirubinemia. To discover associations with variants in genes other than UGT1A1, we undertook a genome-wide association study. We recruited 200 participants to cover the entire range of quantitative variation in UCB level. The data set -- after data curation, including analyses for population stratification and cryptic relatedness -- comprised genotypes at 512,349 SNP loci on 182 individuals. Quantitative trait locus (QTL) association analyses were performed, after adjusting the UCB level for effects of age, gender, and genotype at the dinucleotide (TA) insertion locus in UGT1A1 that is known to significantly modulate UCB level. A significant association of a polymorphic marker (rs2328136) near the NUP153 gene (which produces a 153 kDa nucleoporin) was obtained (p = 0.002, after multiple-testing correction). The frequency of the variant allele (A) at the rs2328136 locus in our study population is 40%, higher than most global populations. NUP153, whose product is a major regulatory factor in bidirectional transport of biomolecules across nucleus to cytosol, is associated with the transport of biliverdin reductase, which is important for bilirubin conjugation.


Asunto(s)
Bilirrubina/sangre , Proteínas de Complejo Poro Nuclear/genética , Polimorfismo de Nucleótido Simple , Adulto , Femenino , Marcadores Genéticos , Estudio de Asociación del Genoma Completo , Glucuronosiltransferasa/genética , Humanos , Hiperbilirrubinemia/genética , Masculino , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/metabolismo , Sitios de Carácter Cuantitativo
9.
Biometrics ; 68(2): 361-70, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22313248

RESUMEN

In a typical case-control study, exposure information is collected at a single time point for the cases and controls. However, case-control studies are often embedded in existing cohort studies containing a wealth of longitudinal exposure history about the participants. Recent medical studies have indicated that incorporating past exposure history, or a constructed summary measure of cumulative exposure derived from the past exposure history, when available, may lead to more precise and clinically meaningful estimates of the disease risk. In this article, we propose a flexible Bayesian semiparametric approach to model the longitudinal exposure profiles of the cases and controls and then use measures of cumulative exposure based on a weighted integral of this trajectory in the final disease risk model. The estimation is done via a joint likelihood. In the construction of the cumulative exposure summary, we introduce an influence function, a smooth function of time to characterize the association pattern of the exposure profile on the disease status with different time windows potentially having differential influence/weights. This enables us to analyze how the present disease status of a subject is influenced by his/her past exposure history conditional on the current ones. The joint likelihood formulation allows us to properly account for uncertainties associated with both stages of the estimation process in an integrated manner. Analysis is carried out in a hierarchical Bayesian framework using reversible jump Markov chain Monte Carlo algorithms. The proposed methodology is motivated by, and applied to a case-control study of prostate cancer where longitudinal biomarker information is available for the cases and controls.


Asunto(s)
Biometría/métodos , Estudios de Casos y Controles , Modelos Estadísticos , Teorema de Bayes , Bases de Datos Factuales/estadística & datos numéricos , Enfermedad/etiología , Humanos , Funciones de Verosimilitud , Estudios Longitudinales , Masculino , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/etiología , Estudios Retrospectivos , Riesgo
10.
Hemoglobin ; 36(1): 57-63, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22004064

RESUMEN

India is in the thalassemia belt of the world. Both α- and ß-thalassemia (α- and ß-thal) are found in West Bengal, a state in the eastern part of India. There was no systematic large published study to investigate the prevalence rates of different hemoglobinopathies in West Bengal. This study was conducted in school and college students, newly married couples and pregnant women after proper counseling in the rural areas of five districts of West Bengal state in eastern India. Thalassemia testing was done using high performance liquid chromatography (HPLC). A total of 35,413 individuals were screened for hemoglobinopathies. ß-Thalassemia trait was found in 10.38%, Hb E [ß26(B8)Glu→Lys] trait in 4.30%, sickle cell trait in 1.12%, borderline Hb A(2) value 0.73%, low Hb A(2) 0.68% and Hb D trait 0.37%. This is the first study that addresses the prevalence of different hemoglobinopathies in rural areas of West Bengal. The prevalence of ß-thal trait is higher in West Bengal than other parts of India. This data is likely to be helpful in planning screening programs in rural areas of West Bengal, India.


Asunto(s)
Pruebas Genéticas/métodos , Hemoglobinopatías/epidemiología , Hemoglobinopatías/genética , Salud Rural/estadística & datos numéricos , Adolescente , Adulto , Femenino , Frecuencia de los Genes , Genotipo , Hemoglobina A2/genética , Hemoglobina E/genética , Hemoglobina Falciforme/genética , Hemoglobinas Anormales/genética , Humanos , India/epidemiología , Masculino , Embarazo , Complicaciones Hematológicas del Embarazo/epidemiología , Complicaciones Hematológicas del Embarazo/genética , Prevalencia , Adulto Joven , Talasemia beta/epidemiología , Talasemia beta/genética
11.
Sankhya B (2008) ; 84(2): 449-471, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34658600

RESUMEN

The paper intends to serve two objectives. First, it revisits the celebrated Fay-Herriot model, but with homoscedastic known error variance. The motivation comes from an analysis of count data, in the present case, COVID-19 fatality for all counties in Florida. The Poisson model seems appropriate here, as is typical for rare events. An empirical Bayes (EB) approach is taken for estimation. However, unlike the conventional conjugate gamma or the log-normal prior for the Poisson mean, here we make a square root transformation of the original Poisson data, along with square root transformation of the corresponding mean. Proper back transformation is used to infer about the original Poisson means. The square root transformation makes the normal approximation of the transformed data more justifiable with added homoscedasticity. We obtain exact analytical formulas for the bias and mean squared error of the proposed EB estimators. In addition to illustrating our method with the COVID-19 example, we also evaluate performance of our procedure with simulated data as well.

12.
J Colloid Interface Sci ; 606(Pt 1): 353-366, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34392031

RESUMEN

Design and facile fabrication of a magnetically separable hetero-structure photocatalyst as well as an adsorbent having dual green benefits towards energy conversion and pollutant remediation are quite indispensable in the current scenario. In this regard, a composite of citrate capped Fe3O4 and UiO-66-NH2 has been designed to remediate Cr (VI) by adsorption and harvest photons from visible light for clean energy (H2) conversion. The material was prepared by the union of citrate capped Fe3O4 (CCM) and versatile aqueous stable Zr-based MOF (UiO-66-NH2) through in-situ solvothermal method. The composite of CCM with MOF (MU-2) was studied through sophisticated analysis techniques; PXRD, FT-IR, BET, UV-Visible DRS, PL, TG, HRTEM and XPS etc. to reveal the inherent characteristics of the material. BET surface analysis revealed high specific surface area (572.13 m2 g-1) of MU-2 in comparison to its pristine MOF. Furthermore, the dual function composite MU-2's VSM studies showed that its magnetic saturation is 3.07 emu g-1 that is suitable for magnetic separation after desired reaction from aqueous media. The Cr (VI) sorption studies revealed that the composite adsorbent (MU-2) showed maximum monolayer adsorption capacity (Qm) of 743 mg g-1 which followed pseudo second order kinetics. Moreover, the sorption thermodynamics revealed that the process was spontaneous and endothermic in nature. In addition to it, the synthesized composite material displayed enhanced activity towards photocatalytic H2 evolution with a maximum evolution rate of 417 µmole h-1 with an apparent conversion efficiency (ACE) of 3.12 %. Typically, MU-2 displays high adsorptions of Cr (VI) as well as some extent of Cr (VI) reduction owning to its populous active sites and free carboxylate groups respectively. Moreover, the synergistic effect of CCM and UNH in the composite resulted in Z scheme mediated charge transfer mechanism that showed enhanced H2 photo-evolution rates. Hence, MU-2 can be readily utilized as magnetically retrievable dual function composite for Cr (VI) adsorption and photocatalytic H2 evolution.

13.
Blood Coagul Fibrinolysis ; 32(3): 167-171, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33827111

RESUMEN

Coronavirus disease 2019 infection produce a prothrombotic state. This is initiated through multiple pathways and is finally aggravated by cross talks with cytokine storm and neutrophil, platelet, complement activation. All these combine towards the second week of illness to produce thrombosis in the lung capillaries surrounding the alveolus producing characteristic pulmonary dysfunction (PaO2/FiO2 > 300, normal or minimally increased lung compliance and very high d-dimer levels) and a high rate of peripheral venous thrombosis. International and many national guidelines have approached this state in different ways but all emphasized the need for management and prevention of widespread thrombosis. It is felt more aggressive and graded thrombosis prevention and management should be initiated early in the treatment. d-Dimer, neutrophil count, SaO2, fibrinogen levels should be used to control the hypercoagulability. Drugs like statins which have anti-inflammatory action as well as ability to reduce fibrinogen and other clotting factors should be used in the beginning along with antiplatelet drugs and progressively complement activation and neutrophil extracellular traps inhibitors, oral mucopolysaccharides, full-scale anticoagulation along with judicial use of fibrinolysis supporting drugs should be added. In the present review, we have evaluated the various studies and argued the rationality that the anticoagulation in this condition should be initiated early during the infection and should be increased in a graded manner depending on clinical and laboratory progression of the condition until a strong specific antiviral drug for coronavirus disease 2019 infection is available.


Asunto(s)
Coagulación Sanguínea/efectos de los fármacos , Tratamiento Farmacológico de COVID-19 , COVID-19/fisiopatología , Trombofilia/tratamiento farmacológico , Trombosis/tratamiento farmacológico , Anticoagulantes/uso terapéutico , Antivirales/uso terapéutico , Plaquetas/efectos de los fármacos , Trampas Extracelulares/efectos de los fármacos , Fibrinolíticos/uso terapéutico , Glicosaminoglicanos/farmacología , Glicosaminoglicanos/uso terapéutico , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Inflamación/tratamiento farmacológico , Pulmón/efectos de los fármacos , Pulmón/fisiopatología , Pulmón/virología , Inhibidores de Agregación Plaquetaria/uso terapéutico
14.
ACS Omega ; 6(23): 14903-14910, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-34151072

RESUMEN

Manganese nodules from ocean bed are potential resources of Cu, Ni, and Co for which land-based deposits are scarce in India. The present work describes a novel approach of using glycerol, a nontoxic biomass-derived reductant, for the reductive acid leaching of manganese nodules. Parameters such as acid concentration, time, temperature, and pulp density were optimized for leaching. The optimal leaching conditions were found to be 10% (w/v) pulp density and 10% (v/v) H2SO4 at 80 °C with 1% (v/v) glycerol yielding >95% of Ni and >98% Cu, Co, and Mn extraction within an hour. Kinetic analysis of the data based on the initial rate method showed that the leaching process was chemical reaction-controlled with an apparent activation energy of 55.47 kJ/mol. Various oxidation intermediates of glycerol formed during leaching were identified using mass spectrometry and Raman spectroscopy, and a probable oxidation pathway of glycerol during the leaching process has been elucidated based on the analysis. Glycerol was oxidized to glyceraldehyde, glyceric acid, tartronic acid, dihydroxyacetone, hydroxy pyruvic acid, glyoxalic acid, oxalic acid, and finally converted to CO2 during leaching. The fast reaction kinetics, near-complete dissolution of manganese, and other associated metals in the nodule can be attributed to the participation of all intermediate products of glycerol oxidation in redox reactions with MnO2, enhancing the overall reduction leaching efficiency.

15.
ACS Omega ; 6(1): 188-196, 2021 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-33458471

RESUMEN

A complete process flowsheet to recover metal values from Sm2Co17-type magnet scrap was investigated. The magnet scrap was leached in chloride medium at pulp density of 2% (w/v) under the optimum conditions of 15% (v/v) HCl and 5% (v/v) H2O2 at 70 °C for 3 h, which yielded 98.5% Sm and 99% Co extractions. The full factorial Design of Experiment technique was adopted for the optimization of leaching conditions. Sm was selectively separated from the leach liquor as precipitated double salt using Na2SO4. The precipitated double sulfate was later converted to Sm-oxalate, which was subsequently calcined to produce pure Sm2O3. Following Sm separation, Fe was removed through precipitation by raising the pH to 3.0. For Cu and Co recovery, solvent extraction techniques using LIX 84I and Na-CYANEX 272, respectively, were followed. The McCabe-Thiele diagrams for extraction as well as stripping were presented for both Cu and Co.

16.
Biometrics ; 66(3): 934-48, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19930190

RESUMEN

With increasing frequency, epidemiologic studies are addressing hypotheses regarding gene-environment interaction. In many well-studied candidate genes and for standard dietary and behavioral epidemiologic exposures, there is often substantial prior information available that may be used to analyze current data as well as for designing a new study. In this article, first, we propose a proper full Bayesian approach for analyzing studies of gene-environment interaction. The Bayesian approach provides a natural way to incorporate uncertainties around the assumption of gene-environment independence, often used in such an analysis. We then consider Bayesian sample size determination criteria for both estimation and hypothesis testing regarding the multiplicative gene-environment interaction parameter. We illustrate our proposed methods using data from a large ongoing case-control study of colorectal cancer investigating the interaction of N-acetyl transferase type 2 (NAT2) with smoking and red meat consumption. We use the existing data to elicit a design prior and show how to use this information in allocating cases and controls in planning a future study that investigates the same interaction parameters. The Bayesian design and analysis strategies are compared with their corresponding frequentist counterparts.


Asunto(s)
Teorema de Bayes , Estudios de Casos y Controles , Ambiente , Estudios de Asociación Genética , Animales , Arilamina N-Acetiltransferasa , Conducta , Bovinos , Neoplasias Colorrectales/epidemiología , Dieta , Exposición a Riesgos Ambientales , Humanos , Carne , Factores de Riesgo , Tamaño de la Muestra , Fumar
17.
J Biomol Struct Dyn ; 38(7): 2038-2046, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31282288

RESUMEN

Graphene based materials have attracted global attention due to their excellent properties. GO-metal oxide nanocomposites have been conjugated with biomolecules for the development of novel materials and potentially used as biomarkers. Herein, a detailed study on the interaction of Bovine serum albumin (BSA) with MnO2@RGO (manganese dioxide-reduced graphene oxide) nanocomposites (NC) has been carried out. MnO2@RGO nanocomposites were prepared through a template/surfactant free hydrothermal route at 180 °C for 12 h by varying the graphene oxide (GO) concentration. Different biophysical experiments have been carried out to evaluate molecular interactions between BSA and NCs. Intrinsic fluorescence has been used to quantify the quenching efficiency of NCs and the binding association of BSA-NC complexes. NCs effectively quenched the intrinsic fluorescence of BSA via static and dynamic mechanism. Further, the results indicate that the molecular interactions of NC with BSA are dependent on the GO percentage in NC. Circular dichroism results demonstrate nominal changes in the secondary structure of BSA in presence of NCs. Also, the esterase-like activity of BSA was marginally affected after adsorption upon NCs. In addition, the FESEM micrographs reveal that the protein-NC complexes consist of nanorod and sheet-like morphologies are forming aggregates of different sizes. We hope that this study will provide a basis for the design of novel graphene based and other related nanomaterials for several biological applications.Communicated by Ramaswamy H. Sarma.


Asunto(s)
Grafito , Nanocompuestos , Compuestos de Manganeso , Óxidos , Albúmina Sérica Bovina
18.
ACS Omega ; 5(25): 14990-14998, 2020 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-32637772

RESUMEN

To recover potassium from feldspar, a biowaste, i.e., eggshell, was used. The chief composition of eggshells is calcite. As it is a rich source of Ca, hence it is used with HCl to produce calcium chloride. Feldspar is an aluminosilicate mineral that bears potassium in the interstitial sites. To unlock the potassium from the interstitial sites, it was roasted with calcium chloride prepared by mixing eggshell and hydrochloric acid. At the roasting temperature, CaCl2 melts and penetrates into the aluminosilicate matrix to replace K with Ca. Potassium ion released from the silicate matrix combines with chloride ions to form potassium chloride, which solubilized in water during the leaching process of the roasted feldspar. For elucidation of the mechanism of the roasting process, the shrinking core model was applied to the roast-leach data, and diffusion through the product layer was inferred as the rate-determining step. The order of the roasting process was found to be 2.158 and activation energy calculated to be 155.3 kJ/mol. Apart from potassium, sodium and excess calcium also got co-leached. To recover potassium from the leach liquor selectively, sodium perchlorate was added to precipitate potassium as KClO4. Further, potassium perchlorate was thermally decomposed to give fertilizer grade potassium chloride (purity: 99.81%).

19.
Indian J Hematol Blood Transfus ; 36(3): 535-541, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32647429

RESUMEN

Hb E-beta thalassemia is a major public health problem in West Bengal, India and is the predominant symptom producing thalassemia in this part of the country. To search for an easy, reliable and cost effective screening method for HbE that can be used at the community level where more sophisticated methods are not readily available. And the DCIP test was performed for the purpose. Blood samples of 425 asymptomatic family members from 80 diagnosed cases of HbE beta Thalassemia patients were tested for Hb, RBC indices, DCIP test, HPLC, and in discordant cases confirmed by DNA mutation analysis. The present study shows DCIP screening test to have a sensitivity, specificity, positive predictive value and negative predictive value of 96.39%, 97.43%, 96.39% and 97.43% respectively. It also shows a false positive rate and false negative rate in 2.56% and 4.6% cases respectively. The advantage with DCIP over HPLC is that it can be easily performed at the community level by a person with minimum technical skill, few samples (even a single sample) can be tested at time, at a low cost.

20.
Hemoglobin ; 33(6): 486-91, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19958194

RESUMEN

Point mutations of alpha-globin genes in homozygous or in compound heterozygous states cause severe alpha-thalassemia (alpha-thal). Here we describe a polymerase chain reaction-restriction fragment length polymorphism-based method for easy detection of the point mutation Hb Sallanches [alpha104(G11)Cys-->Tyr, TGC>TAC], earlier detected by a sequencing technique. In a cohort of 104 unrelated putative alpha-thal patients, nine carried the mutation and two were homozygotes. The mutation occurred on both the alpha2- or alpha1-globin genes. The phenotypes, in conjunction with other point mutations or deletions, are presented. Earlier detected in Pakistan and Punjab of India, it is probably present all over the Indian subcontinent.


Asunto(s)
Hemoglobinas Anormales/genética , Talasemia alfa/genética , Frecuencia de los Genes , Humanos , Incidencia , India/epidemiología , Fenotipo , Mutación Puntual , Polimorfismo de Longitud del Fragmento de Restricción
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA