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1.
Phys Rev Lett ; 127(11): 113001, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34558915

RESUMO

We observe experimentally the spontaneous formation of star-shaped surface patterns in driven Bose-Einstein condensates. Two-dimensional star-shaped patterns with l-fold symmetry, ranging from quadrupole (l=2) to heptagon modes (l=7), are parametrically excited by modulating the scattering length near the Feshbach resonance. An effective Mathieu equation and Floquet analysis are utilized, relating the instability conditions to the dispersion of the surface modes in a trapped superfluid. Identifying the resonant frequencies of the patterns, we precisely measure the dispersion relation of the collective excitations. The oscillation amplitude of the surface excitations increases exponentially during the modulation. We find that only the l=6 mode is unstable due to its emergent coupling with the dipole motion of the cloud. Our experimental results are in excellent agreement with the mean-field framework. Our work opens a new pathway for generating higher-lying collective excitations with applications, such as the probing of exotic properties of quantum fluids and providing a generation mechanism of quantum turbulence.

2.
Nanotechnology ; 31(9): 095705, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-31715590

RESUMO

Nanomaterials exhibit different interesting physical, chemical, electronic and magnetic properties that can be used in a variety of biomedical applications such as molecular imaging, cancer therapy, biosensing, and targeted drug delivery. Among various types of nanoparticles, super paramagnetic iron oxide nanoparticles (SPIONs) have emerged as exogenous contrast agents for in vitro and in vivo deep tissue imaging. Here, we propose a facile, rapid, non-toxic, and cost-effective single step green synthesis method to fabricate eugenate (4-allyl-2-methoxyphenolate) capped iron oxide nanoparticles (E-capped IONPs). The magnetic E-capped IONPs are first time synthesized using a medicinal aromatic plant, Pimenta dioica. The Pimenta dioica leaf extract was used as a natural reducing agent for E-capped IONPs synthesis. The crystalline structure and size of the synthesized spherical nanoparticles were confirmed using the x-ray diffraction and electron microscopic images respectively. In addition, the presence of the functional groups, responsible for capping and stabilizing the synthesized nanoparticles, were identified by the Fourier transform infra-red spectrum. These nanoparticles were found to be safe for human cervical cancer (HeLa) and human embryonic kidney 293 (HEK 293) cell lines and their safety was established using MTT[3-(4, 5-Dimethylthiazol-2-yl)-2, 5-Diphenyltetrazolium Bromide] assay. These green synthesized E-capped IONPs display a distinct absorbance in the tissue transparent near-infrared (NIR) wavelength region. This property was used for the NIR photothermal application of E-capped IONPs. The results suggest that these E-capped IONPs could be used for deep tissue photothermal therapy along with its application as an exogenous contrast agent in biomedical imaging.

3.
Phys Chem Chem Phys ; 22(10): 5893-5901, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32110783

RESUMO

Phosphorene has a unique set of characteristics such as a semiconducting nature, good carrier mobility and low-spin orbit coupling aspects which makes it a highly prospective two dimensional material for cross-hybrid architectures in nanoelectronics, spintronics, and optoelectronics. In the spintronic context, the creation of a stable magnetic order in phosphorene can be immensely beneficial for designing phosphorene spin circuits. In this work, we present high efficiency spin filtering behaviour in magnetically rendered phosphorene. First, we calculate the effect of doping various 3d block elements in phosphorene to introduce a stable magnetic order. Next, by varying doping concentrations in distinct doping configurations, an extensive phase diagram has been obtained depicting the presence of various electronic and magnetic states. This allows us to achieve a high magnetisation in the presence of various transition metal atoms, with a spin polarisation of ∼100% in half-metallic regimes. The transport behaviour reveals a map of the spin injection efficiency showing enhancement with doping concentration and reaching a perfect spin filtering capacity of ∼100% in the presence of Ti, Cr, Mn, Co, and Fe atoms. The present results offer new insights into engineered designs of multi-functional phosphorene spintronic circuits.

4.
Breast Cancer Res Treat ; 169(3): 457-467, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29464534

RESUMO

PURPOSE: High expression of glioma-associated oncogene homolog-1 (GLI1) is associated with poor prognosis in estrogen receptor (ER) positive breast cancers. We sought to define a GLI1-dependent gene signature in ER-positive tumors that could further stratify patients at higher risk for disease recurrence and potentially lead to novel combination therapies. METHODS: We identified an inverse correlation between GLI1 expression and distant disease-free survival (DFS) using a dataset developed at MD Anderson Cancer Center (Hatzis dataset) containing clinical data from 508 breast cancer patients. Using a qPCR-based microarray platform, we identified genes differentially regulated by GLI1 in MCF7 cells and then determined if expression of these genes correlated with GLI1 expression in patient tumor samples. Statistical comparison between the groups was performed by ANOVA. Direct comparison of two groups was done by a two-tailed t test. Correlations between variables were done by Pearson's method. RESULTS: Expression of GLI1 and its target genes correlated significantly with worse distant DFS in breast cancer patients with Luminal A molecular subtype. Particularly, co-expression of GLI1 with EGFR and/or SNAI1, two of the identified GLI1 targets, was predictive of worse distant DFS in this subtype. Furthermore, patients with Luminal A tumors with a high GLI1 signature had a shorter distant DFS compared to the Luminal B subtype and the outcome for this group was comparable to patients with HER2-positive or basal-like tumors. CONCLUSION: We have identified a novel GLI1 gene signature that is associated with worse clinical outcomes among the patients with Luminal A subtype of breast cancer.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas Hedgehog/metabolismo , Transdução de Sinais , Adulto , Biomarcadores Tumorais , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Sobrevivência Celular , Resistencia a Medicamentos Antineoplásicos , Expressão Ectópica do Gene , Feminino , Perfilação da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Análise de Sobrevida , Transcriptoma , Proteína GLI1 em Dedos de Zinco/genética , Proteína GLI1 em Dedos de Zinco/metabolismo
5.
Trop Anim Health Prod ; 50(4): 889-895, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29374345

RESUMO

The objective of this study was to monitor the changes in growth, dry matter intake, and blood profiles (nutrition and reproductive hormones) of dairy heifers in response to green grass-based diets. Twelve crossbred heifers were equally divided into group 1: rice straw and concentrate; group 2: rice straw, green grass, and concentrate; group 3: green grass and concentrate; group 4: green grass, soybean hay, and concentrate. Dry matter intake in group 4 was found 6% higher (P < 0.05) than group 1. Negative body weight gain was found in group 1 and group 2 showed 14% higher body weight gain per 30 days compared to groups 3 and 4 (P < 0.05). Heifers in group 4 had significantly (P < 0.05) higher heart girth gain, serum albumin, urea, and blood urea nitrogen than the heifers in other groups. Endocrine parameters were found similar among groups. Overall, supply of green grass especially a mix of leguminous and non-leguminous was found advantageous in heifer feeding.


Assuntos
Ração Animal , Bovinos/sangue , Dieta/veterinária , Poaceae , Animais , Nitrogênio da Ureia Sanguínea , Peso Corporal , Bovinos/crescimento & desenvolvimento , Indústria de Laticínios , Fabaceae , Feminino , Gonadotropinas Hipofisárias/sangue , Estado Nutricional , Progesterona/sangue , Reprodução , Glycine max , Aumento de Peso
6.
Phys Chem Chem Phys ; 19(34): 23431-23443, 2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28828413

RESUMO

For chemi-resistive thin film gas sensors a generic theoretical model is proposed to predict the variation of sensor response with the operating temperature and thickness of the sensing film. A diffusion equation is formulated assuming that inflammable target gases move through the sensing film by Knudsen diffusion and react with the adsorbed oxygen following first-order kinetics. We have assumed a realistic non-linear variation between the conductance and test gas concentration and derived a general expression relating the sensor response to the operating temperature and thickness of the film. Assuming Langmuir adsorption kinetics, we have theoretically predicted the response and recovery transients during gas sensing using thin film sensing elements. It is predicted that for irreversible type sensing, the response time is reduced with an increase in test gas concentration, whereas for reversible sensing, the response time is independent of test gas concentration. For zinc oxide thin film sensors, an excellent match is obtained between the model prediction and experimental data for their thickness (122 nm to 380 nm) and temperature variation (200 °C to 325 °C) in 500 ppm carbon monoxide (CO) sensing. The maximum CO response% (∼53%) was achieved in 320 nm thick ZnO films. The conductance transients for response and recovery for CO sensing closely follow Langmuir adsorption kinetics and as predicted theoretically, indeed for irreversible sensing, the response time reduces from 350 s to 220 s with an increase in test gas concentration from 20 to 550 ppm. In the case of reversible sensing we found that the response time is ∼55 s irrespective of the CO gas concentration in the range of 5-500 ppm. The models developed in the present work are quite generic in nature and we have discussed their applicability to a wide variety of sensing materials with various types of surface morphologies.

7.
Mymensingh Med J ; 25(4): 746-750, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27941741

RESUMO

Cyclone Aila hit the South-West coast of Bangladesh in May 2009, when in Dacope Upazilla over 50,000 people were left homeless as climate refugees (CRs) for over two years. We determined neurodevelopmental status of children born as CRs compared to their non-Climate Refugee (NCR) counterparts. Pregnant mothers were enrolled from May 2009 to April 2010 in entire Dacope in a study which profiled their health conditions. From among these mothers, 12 months post-Aila 267 CR mother-child dyads, and 552 NCR mother-child dyads were enrolled to assess their children's neurodevelopmental outcomes. There were significantly more landless families among CRs compared to NCRs (p value = 0.0001; OR = 1.86, 95% CI: 1.37 - 2.51). The mean±SD age at assessment of CR children was 8.52±4.57 months compared to a mean age 9.09±4.13 months of the NCR children (p=0.610). Neurodevelopmental Impairments (NDIs) were three times higher in the former (21.3%), compared to the latter (7.4%) group (p=0.0001; OR 3.83, 95% CI: 2.16 - 5.21). Specifically, expressive language (p value 0.002; OR 2.86, 95% CI: 1.46 - 5.57) and gross motor functions (p=0.007; OR 2.27, 95% CI 1.22 - 4.20) were the most significantly affected areas of impairment. Children born to CR mothers had a three times higher proportion of NDIs. The findings are of concern as in Bangladesh large populations are forced to leave their homes and become CRs annually. Optimum antenatal care of pregnant women as well as their offsprings within refugee situations needs to be ensured to prevent NDIs and poor quality of survival.


Assuntos
Refugiados , Bangladesh , Sistema Nervoso Central , Criança , Clima , Tempestades Ciclônicas , Feminino , Humanos , Mães , Gravidez
9.
Analyst ; 139(7): 1796-800, 2014 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-24551870

RESUMO

In the present work we have grown highly textured, ultra-thin, nano-crystalline zinc oxide thin films using a metal organic chemical vapor deposition technique and addressed their selectivity towards hydrogen, carbon dioxide and methane gas sensing. Structural and microstructural characteristics of the synthesized films were investigated utilizing X-ray diffraction and electron microscopy techniques respectively. Using a dynamic flow gas sensing measurement set up, the sensing characteristics of these films were investigated as a function of gas concentration (10-1660 ppm) and operating temperature (250-380 °C). ZnO thin film sensing elements were found to be sensitive to all of these gases. Thus at a sensor operating temperature of ~300 °C, the response% of the ZnO thin films were ~68, 59, and 52% for hydrogen, carbon monoxide and methane gases respectively. The data matrices extracted from first Fourier transform analyses (FFT) of the conductance transients were used as input parameters in a linear unsupervised principal component analysis (PCA) pattern recognition technique. We have demonstrated that FFT combined with PCA is an excellent tool for the differentiation of these reducing gases.

10.
Mymensingh Med J ; 23(2): 392-4, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24858174

RESUMO

Solid pseudopapillary tumour of pancreas (SPT) is an extremely rare pancreatic tumour, which has a low malignant potential and occurs mainly in young women. Pathologic and imaging findings include a well defined encapsulated pancreatic mass with cystic and solid components with evidence of haemorrhage. This is a case of a 16 years old girl who presented with upper abdominal pain of long duration and epigastric mass on palpation. Computed Tomography (CT) scan demonstrated a large well defined heterogenous attenuation mass of solid enhancing and cystic non enhancing areas, arising from the head of the pancreas. Radiologically it was diagnosed as a case of pancreatic neoplasm. Fine needle aspiration cytology (FNAC) and histopathology of the biopsy material diagnosed as solid pseudopapillary tumour of pancreas.


Assuntos
Carcinoma Papilar/diagnóstico , Carcinoma Papilar/terapia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/terapia , Adolescente , Feminino , Humanos
11.
Mymensingh Med J ; 23(2): 401-5, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24858176

RESUMO

Uterine prolapse is commonly seen in the geriatric age group. Congenital vaginouterine prolapse is a rare condition occurring in neonates and is usually associated with spinal cord malformations in about 85% of cases. Several modalities of treatment have been described for neonatal uterine prolapse. Conservative treatment in the form of simple digital reposition, use of pessary or other self-retaining device is usually sufficient to treat this condition, which is self-limiting and regressive. Here we report our first case of neonatal uterine prolapse, managed successfully with simple digital reposition.


Assuntos
Prolapso Uterino/congênito , Prolapso Uterino/terapia , Feminino , Humanos , Recém-Nascido , Prolapso Uterino/diagnóstico
12.
Mymensingh Med J ; 33(2): 365-372, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38557512

RESUMO

Hypertension is a common disorder of major clinical, public health and economic importance. It affects men and women of all ages, and the prevalence is increasing in most countries. Maintenance of blood pressure below 140/90 mm of Hg is recommended by most of the guideline available around the world. Various classes of drugs are being used in the treatment of hypertension. Losartan potassium and amlodipine are two different antihypertensive agents belonging to two different groups used commonly around the world in treating essential hypertension. Losartan potassium is non-peptide Angiotensin-II receptor antagonist. Amlodipine which is the third generation dihydropyridine group of calcium channel blocker. The aim of the study was to compare the efficacy and safety of amlodipine and losartan for the treatment of essential hypertensive patients (18-75 years). A non-randomized comparative observational study was conducted in the Department of Pharmacology and Therapeutics in collaboration with Department of Medicine, Sylhet, MAG Osmani Medical College, Sylhet, Bangladesh from July 2021 to June 2022. In this study non-randomization was in two groups. Group A received amlodipine 5mg daily at morning and Group B received losartan potassium 50mg daily at night. The study parameters were systolic blood pressure (SBP), diastolic blood pressure (DBP), ankle oedema, serum K+ level. The result of treatment outcome was compared between two groups. After treatment the reduction of SBP was 5.19±2.93mm of Hg versus 3.27±1.34mm of Hg (p<0.001); reduction of DBP was 1.7±0.70 mm of Hg versus 0.68 mm of Hg (p<0.001) and serum K+ level 4.22±0.27mmol/L versus 4.21±0.16mmol/L (p<0.719) in amlodipine and losartan group respectively. Amlodipine is more effective than losartan potassium in respect to treatment of essential hypertension. Regarding adverse events losartan potassium causes angioedema, hyperkalemia, headache, dizziness etc. The study concluded that amlodipine is superior to losartan potassium in treating essential hypertension.


Assuntos
Hipertensão , Mercúrio , Masculino , Humanos , Feminino , Losartan/uso terapêutico , Losartan/farmacologia , Anlodipino/uso terapêutico , Anlodipino/farmacologia , Bangladesh , Centros de Atenção Terciária , Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Hipertensão Essencial/tratamento farmacológico , Hipertensão Essencial/induzido quimicamente , Pressão Sanguínea , Resultado do Tratamento , Mercúrio/farmacologia , Mercúrio/uso terapêutico , Método Duplo-Cego
13.
Sci Rep ; 14(1): 9138, 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38644366

RESUMO

Phosphorene is a unique semiconducting two-dimensional platform for enabling spintronic devices integrated with phosphorene nanoelectronics. Here, we have designed an all phosphorene lattice lateral spin valve device, conceived via patterned magnetic substituted atoms of 3d-block elements at both ends of a phosphorene nanoribbon acting as ferromagnetic electrodes in the spin valve. Through First-principles based calculations, we have extensively studied the spin-dependent transport characteristics of the new spin valve structures. Systematic exploration of the magnetoresistance (MR) of the spin valve for various substitutional atoms and bias voltage resulted in a phase diagram offering a colossal MR for V and Cr-substitutional atoms. Such MR can be directly attributed to their specific electronic structure, which can be further tuned by a gate voltage, for electric field controlled spin valves. The spin-dependent transport characteristics here reveal new features such as negative conductance oscillation and switching of the sign of MR due to change in the majority spin carrier type. Our study creates possibilities for the design of nanometric spin valves, which could enable integration of memory and logic elements for all phosphorene 2D processors.

14.
Phys Rev E ; 108(3-1): 034102, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37849185

RESUMO

We examine the quench dynamics of an extended Su-Schrieffer-Heeger (SSH) model involving long-range hopping that can hold multiple topological phases. Using winding number diagrams to characterize the system's topological phases geometrically, it is shown that there can be multiple winding number transition paths for a quench between two topological phases. The dependence of the quench dynamics is studied in terms of the survival probability of the fermionic edge modes and postquench transport. For two quench paths between two topological regimes with the same initial and final topological phase, the survival probability of edge states is shown to be strongly dependent on the winding number transition path. This dependence is explained using energy band diagrams corresponding to the paths. Following this, the effect of the winding number transition path on transport is investigated. We find that the velocities of maximum transport channels varied along the winding number transition path. This variation depends on the path we choose, i.e., it increases or decreases depending upon the path. An analysis of the coefficient maps, energy spectrum, and spatial structure of the edge states of the final quench Hamiltonian provides an understanding of the path-dependent velocity variation phenomenon.

15.
Artigo em Inglês | MEDLINE | ID: mdl-37807947

RESUMO

Arrhythmic heartbeat classification has gained a lot of attention to accelerate the detection of cardiovascular diseases and mitigating the potential cause of one-third of deaths worldwide. In this article, a computer-aided diagnostic (CAD) approach has been proposed for the automated identification and classification of arrhythmic heartbeats from electrocardiogram (ECG) signals using multiple features aided supervised learning model. For proper diagnosis of arrhythmic heartbeats, MIT-BIH Arrhythmia database has been used to train and test the proposed approach. The ECG signals, extracted from sensor leads, have undergone pre-processing via discrete wavelet transform. Three sets of features, i.e. statistical, temporal, and spectral, are extracted from the processed ECG signals followed by random forest aided recursive feature elimination strategy to select the prominent features for proper classification of arrhythmic heartbeats by the proposed optimal extreme gradient boosting (O-XGBoost) classifier. Hyperparameters such as learning rate, tree-specific parameters, and regularization parameters have been optimized to improve the performance of the XGBoost classifier. Moreover, the synthetic minority over-sampling technique has been employed for balancing the dataset in order to improve the classification performance. Quantitative results reveal the remarkable performance over state-of-the-art methods. The proposed model can be implemented in any computer-aided diagnostic system with similar topological structures.

16.
Infect Immun ; 80(3): 1007-14, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22252865

RESUMO

Mycoplasma pneumoniae is a significant human respiratory pathogen that causes high morbidity worldwide. No vaccine to prevent M. pneumoniae infection currently exists, since the mechanisms of pathogenesis are poorly understood. To this end, we constructed a P30 cytadhesin mutant (P-130) with a drastically reduced capacity for binding to erythrocytes and an inability to glide on glass substrates. This mutant was determined to be avirulent and cannot survive in the lungs of BALB/c mice. We also ascertained that the previously identified P30 gliding motility mutant II-3R is avirulent and also cannot be recovered from the lungs of mice after infection. Mutant P130 was then assessed for its efficacy as a live attenuated vaccine candidate in mice after challenge with wild-type M. pneumoniae. After vaccination with the P-130 P30 mutant, mice showed evidence of exacerbated disease upon subsequent challenge with the wild-type strain PI1428, which appears to be driven by a Th17 response and corresponding eosinophilia. Our results are in accordance with other reports of vaccine-induced disease exacerbation in rodents and emphasize the need to better understand the basic mechanisms of M. pneumoniae pathogenesis.


Assuntos
Adesinas Bacterianas/genética , Vacinas Bacterianas/efeitos adversos , Vacinas Bacterianas/imunologia , Progressão da Doença , Técnicas de Inativação de Genes , Mycoplasma pneumoniae/imunologia , Pneumonia por Mycoplasma/prevenção & controle , Animais , Aderência Bacteriana , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/genética , Eosinofilia , Eritrócitos/microbiologia , Feminino , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Viabilidade Microbiana , Mycoplasma pneumoniae/genética , Pneumonia por Mycoplasma/imunologia , Pneumonia por Mycoplasma/microbiologia , Células Th17/imunologia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Virulência
17.
J Nanosci Nanotechnol ; 12(4): 2973-82, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22849054

RESUMO

Nanocrystallites La0.8Pb0.2(Fe0.8Co0.2)O3 (LPFC) when bonded through a surface layer (carbon) in small ensembles display surface sensitive magnetism useful for biological probes, electrodes, and toxic gas sensors. A simple dispersion and hydrolysis of the salts in ethylene glycol (EG) in water is explored to form ensembles of the nanocrystallites (NCs) by combustion of a liquid precursor gel slowly in microwave at 70-80 dgrees C (apparent) in a closed container in air. In a dilute sample, the EG molecules mediate hydrolyzed species to configure in small groups in process to form a gel. Proposed models describe how a residual carbon bridges a stable bonded layer of a graphene-oxide-like hybrid structure on the LPFC-NCs in attenuating the magnetic structure. SEM images, measured from a pelletized sample which was used to study the gas sensing features in terms of the electrical resistance, describe plate shaped NCs, typically 30-60 nm widths, 60-180 nm lengths and -50 m2/g surface area (after heating at -750 degrees C). These NCs are arranged in ensembles (200-900 nm size). As per the X-ray diffraction, the plates (a Pnma orthorhombic structure) bear only small strain -0.0023 N/m2 and oxygen vacancies. The phonon and electronic bands from a bonded surface layer disappear when it is etched out slowly by heating above 550 degrees C in air. The surface layer actively promotes selective H2 gas sensor properties.

18.
Ann Hepatol ; 11(6): 870-5, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23109450

RESUMO

BACKGROUND: The prevalence of occult HBV, defined by the presence of HBV DNA in individuals with antibodies to HBV core antigen and with absence of HBV surface antigen, but its clinical significance and virological features in HIV-infected patients is still unclear. AIM: To investigate the prevalence, clinical significance and molecular characterization of occult hepatitis B virus infection in ART-Naive HIV-positive individuals. MATERIAL AND METHODS: Among the 1077 HIV-infected patients with different risk factors for HIV infection, 297 were HBsAg-ve ART-naive, of them 112 was randomly selected for the study. HBV DNA was tested by in-house PCR and quantified by qPCR. Molecular characterization was performed by sequencing the envelope and overlapping polymerase genes. RESULTS: We found the prevalence of occult HBV to be 10.7% among a randomly selected group of HBsAg-ve/antiHBc+ve HIV-infected patients. Overall 33.9% (38 of 112) of the patients were antiHBc positive indicating exposure to HBV infection. HBV DNA was detected in 12/38 (31.5%) antiHBc positive samples and 50% of them had CD4 T cell count < 200 cells/mm(3). HCV coinfection was low (2.7%). No surrogate marker for OBI could be identified. Presence of antiHBs antibodies did not rule out OBI. Liver biopsy in six cases showed varying stages of chronic hepatitis. Several mutations were detected but not the common immune escape mutant G145R. CONCLUSION: In conclusion the prevalence of OBI was significantly high among HIV coinfected patients, which highlights the importance of HBV DNA testing in these patients and indicates need for further prospective studies in larger cohorts to assess its clinical significance.


Assuntos
Coinfecção , Infecções por HIV/epidemiologia , Antígenos do Núcleo do Vírus da Hepatite B/sangue , Vírus da Hepatite B/imunologia , Hepatite B/epidemiologia , Encaminhamento e Consulta , Adolescente , Adulto , Biomarcadores/sangue , Biópsia , Contagem de Linfócito CD4 , Distribuição de Qui-Quadrado , DNA Viral/sangue , Ensaio de Imunoadsorção Enzimática , Feminino , Infecções por HIV/diagnóstico , Hepatite B/diagnóstico , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/genética , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Mutação , Reação em Cadeia da Polimerase , Valor Preditivo dos Testes , Prevalência , RNA Viral/sangue , Análise de Sequência de DNA , Adulto Jovem
19.
Nat Med ; 6(7): 826-31, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10888935

RESUMO

Medulloblastoma is the most malignant pediatric brain tumor. It is believed to originate from the undifferentiated external granule layer cells in the cerebellum, but the mechanism of tumorigenesis remains unknown. Here we studied three types of human medulloblastoma cells that express markers corresponding to different levels of neuronal differentiation. They expressed the neuronal repressor element 1 (RE1) silencing transcription factor/neuron-restrictive silencer factor (REST/NRSF; refs. 7-10) at very high levels compared with either neuronal progenitor NTera2 (NT2) cells or fully differentiated human neuron teratocarcinoma (hNT cells). To counter the effect of REST/NRSF, we used a recombinant transcription factor, REST-VP16, constructed by replacing repressor domains of REST/NRSF with the activation domain of viral protein (VP16). Transient expression of REST-VP16 in medulloblastoma cells was able to compete with the endogenous REST/NRSF for DNA binding and stimulate neuronal promoters. High-efficiency expression of REST-VP16 mediated by adenovirus vectors (Ad.REST-VP16) in medulloblastoma cells was able to counter REST/NRSF-mediated repression of neuronal promoters, stimulate expression of endogenous neuronal genes and trigger apoptosis through the activation of caspase cascades. Furthermore, intratumoral injection of Ad.REST-VP16 in established medulloblastoma tumors in nude mice inhibited their growth. Therefore, REST/NRSF may serve as a new target for therapeutic interventions for medulloblastoma through agents such as REST-VP16.


Assuntos
Neoplasias Cerebelares/genética , Meduloblastoma/genética , Neurônios/citologia , Proteínas Repressoras/metabolismo , Fatores de Transcrição , Adenoviridae/genética , Animais , Apoptose , Diferenciação Celular , Regulação Neoplásica da Expressão Gênica , Proteína Vmw65 do Vírus do Herpes Simples/genética , Proteína Vmw65 do Vírus do Herpes Simples/metabolismo , Humanos , Camundongos , Camundongos Nus , Neoplasias Experimentais/terapia , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/uso terapêutico , Proteínas Repressoras/genética , Células Tumorais Cultivadas
20.
J Assoc Physicians India ; 59: 152-4, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21751623

RESUMO

OBJECTIVE: Despite the advent and expanding access to antiretroviral therapy, HIV-associated cryptococcal meningitis (CM) remains a significant cause of mortality and morbidity amongst individuals with this infection in resource-limited settings. METHODS: We prospectively studied the clinical, biochemical and mycological parameters of 30 HIV patients diagnosed with cryptococcal meningitis at our centre over a period of 6 months with a view to identify prognostic factors predictive of poor outcome. RESULTS: Our study documented a mortality rate of 36.7%. Age, sex and previous diagnosis of HIV had no bearing on the survival outcome of patients. The study identified several poor prognostic factors including low GCS score, papilledema, elevated CSF opening pressure (>250 mm of H2O) and lack of regular HIV care in those with a prior diagnosis of HIV. CSF pleocytosis was significantly higher in the mortality group. CONCLUSION: There have been relatively few attempts to focus on poor prognostic markers associated with AIDS related Cryptococcal meningitis in Asian patients. Our study highlights how simple bedside clinical tools like ophthalmoscopy and CSF manometry can help in risk stratification in this group of patients.


Assuntos
Infecções por HIV/complicações , Meningite Criptocócica/etiologia , Meningite Criptocócica/mortalidade , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/mortalidade , Adulto , Distribuição por Idade , Antifúngicos/uso terapêutico , Biomarcadores , Cryptococcus neoformans/isolamento & purificação , Feminino , Seguimentos , Infecções por HIV/epidemiologia , Humanos , Índia/epidemiologia , Masculino , Meningite Criptocócica/diagnóstico , Meningite Criptocócica/tratamento farmacológico , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Distribuição por Sexo , Análise de Sobrevida , Resultado do Tratamento
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