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1.
J Chromatogr A ; 1646: 462125, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-33894456

RESUMO

3D printing has recently found application in chromatography as a means to create ordered stationary phases with improved separation efficiency. Currently, 3D printed stationary phases are limited by the lack of 3D printing materials suitable for chromatographic applications, and require a strict compromise in terms of desired resolution, model size and the associated print time. Modelling of mass transfer in 3D printed monoliths is also fundamental to understand and further optimise separation performance of 3D printed stationary phases. In this work, a novel 3D printing material was formulated and employed to fabricate monolithic cation exchangers (CEXs) with carboxyl functionalities. CEXs were printed with ligand densities of 0.7, 1.4, 2.1 and 2.8 mmol/g and used in batch adsorption experiments with lysozyme as model protein. All CEXs demonstrated high binding strength towards lysozyme, with maximum binding capacities of up to 108 mg/mL. The experimental results were described using mass transfer models based on lumped pore diffusion and lumped solid diffusion mechanisms adapted to reflect the complex geometry of the 3D printed monoliths. An exact 3D model as well as less computationally demanding 1D and 2D approximations were evaluated in terms of their quality to capture the experimental trend of batch adsorption kinetic data. Overall, the model results indicate that mass transfer in the fabricated CEXs is mostly controlled by pore diffusion at high protein concentrations in the mobile phase, with solid diffusion becoming important at low protein concentrations. Also, the kinetic data were approximated equally well by both the full 3D model as well as the 2D approximation, indicating leaner mathematical models of lower dimensionality can be employed to describe mass transfer in complex three dimensional geometries. We believe this work will help spur the development of 3D printable materials for separations and aid in the development of quantitative platforms to evaluate and optimise the performance of 3D printed monoliths.


Assuntos
Cátions , Modelos Teóricos , Impressão Tridimensional , Adsorção , Cromatografia , Difusão , Cinética
3.
Faraday Discuss ; 208(0): 497-522, 2018 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-29808835

RESUMO

Catalysts made of Pt nanoparticles and Pt alloys are considered state-of-the-art catalysts for the anodic and cathodic reactions involved in hydrogen fuel cells. The optimal size of such nanoparticles for each chemical reaction is an unsolved problem that depends on environmental variables, such as reactant concentration, solvent, temperature, etc. From a theoretical point of view, this problem has been tackled mainly by observing how single key adsorbates react with different nanoparticles under controlled conditions. In this work, we use large-scale DFT calculations to examine the interplay between the Pt nanoparticle size and O coverage effects. We examine single O adsorptions for three adsorption sites on cuboctahedral platinum nanoparticles with different sizes. As we grow the nanoparticle size, the binding strength decreases and we observed a quick convergence of the adsorption energies with increasing nanoparticle size, which correlates with the calculated d-band centre for (111) Pt facets on such nanoparticles. We also carried out a detailed study of the effect of oxygen coverage with varying fractions of O monolayer coverage, computing adsorption energies per O atom for Pt55, Pt147 and Pt309 nanoparticles with several O coverages. In general, an increase of O coverage led to weaker adsorption energies per O atom, and when analysing the results in terms of oxygen monolayers, this effect is more pronounced for larger nanoparticles. The O coverage dependency of the adsorption energy per O atom is analysed in terms of the O distribution for each nanoparticle size and electronic changes that the adsorbed oxygen causes to the Pt nanoparticle. In studying nanoparticle size and oxygen coverage effects simultaneously, we offer insights with DFT accuracy to help on heterogeneous catalyst design.

4.
Phys Chem Chem Phys ; 20(17): 11976-11986, 2018 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-29670963

RESUMO

The diffusion of ammonia in the small pore zeolite and potential commercial NH3-SCR catalyst levynite (LEV) was measured and compared with its mobility in the chabazite (CHA) topology (more established in NOx abatement catalysis), using quasielastic neutron scattering (QENS) and molecular dynamics (MD) simulations at 273, 323 and 373 K. The QENS experiments suggest that mobility in LEV is dominated by jump diffusion through the 8-ring windows between cages (as previously observed in CHA) which takes place at very similar rates in the two zeolites, yielding similar experimental self-diffusion coefficients (Ds). After confirming that the same characteristic motions are observed between the MD simulations and the QENS experiments on the picosecond scale, the simulations suggest that on the nanoscale, the diffusivity is higher by a factor of ∼2 in the CHA framework than in LEV. This difference between zeolites is primarily explained by the CHA cages having six 8-ring windows in the building unit, compared to only three such windows in the LEV cage building unit, thereby doubling the geometric opportunities to perform jump diffusion between cages (as characterised by the QENS experiments) leading to the corresponding increase in the MD calculated Ds. The techniques illustrate the importance of probing both pico- and nanoscale dynamics when studying intracrystalline diffusion in both NH3-SCR catalyst design, and in porous materials generally, where notable consistencies and differences may be found on either scale.

5.
Acta Crystallogr D Struct Biol ; 73(Pt 1): 9-21, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28045381

RESUMO

A number of X-ray analyses of an enzyme involved in a key early stage of tetrapyrrole biosynthesis are reported. Two structures of human 5-aminolaevulinate dehydratase (ALAD), native and recombinant, have been determined at 2.8 Šresolution, showing that the enzyme adopts an octameric quaternary structure in accord with previously published analyses of the enzyme from a range of other species. However, this is in contrast to the finding that a disease-related F12L mutant of the human enzyme uniquely forms hexamers [Breinig et al. (2003), Nature Struct. Biol. 10, 757-763]. Monomers of all ALADs adopt the TIM-barrel fold; the subunit conformation that assembles into the octamer includes the N-terminal tail of one monomer curled around the (α/ß)8 barrel of a neighbouring monomer. Both crystal forms of the human enzyme possess two monomers per asymmetric unit, termed A and B. In the native enzyme there are a number of distinct structural differences between the A and B monomers, with the latter exhibiting greater disorder in a number of loop regions and in the active site. In contrast, the second monomer of the recombinant enzyme appears to be better defined and the active site of both monomers clearly possesses a zinc ion which is bound by three conserved cysteine residues. In native human ALAD, the A monomer also has a ligand resembling the substrate ALA which is covalently bound by a Schiff base to one of the active-site lysines (Lys252) and is held in place by an ordered active-site loop. In contrast, these features of the active-site structure are disordered or absent in the B subunit of the native human enzyme. The octameric structure of the zinc-dependent ALAD from the hyperthermophile Pyrobaculum calidifontis is also reported at a somewhat lower resolution of 3.5 Å. Finally, the details are presented of a high-resolution structure of the Escherichia coli ALAD enzyme co-crystallized with a noncovalently bound moiety of the product, porphobilinogen (PBG). This structure reveals that the pyrrole side-chain amino group is datively bound to the active-site zinc ion and that the PBG carboxylates interact with the enzyme via hydrogen bonds and salt bridges with invariant residues. A number of hydrogen-bond interactions that were previously observed in the structure of yeast ALAD with a cyclic intermediate resembling the product PBG appear to be weaker in the new structure, suggesting that these interactions are only optimal in the transition state.

6.
Phys Chem Chem Phys ; 18(48): 32713-32722, 2016 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-27878153

RESUMO

State-of-the-art catalysts are often created via deposition of monolayers, sub-monolayers or nanoparticles of the catalytic material over supports, aiming to increase the surface area and decrease the loading of the catalytic material and therefore the overall cost. Here, we employ large-scale DFT calculations to simulate platinum clusters with up to 309 atoms interacting with single layer graphene supports with up to 880 carbon atoms. We compute the adsorption, cohesion and formation energies of two and three-dimensional Pt clusters interacting with the support, including dispersion interactions via a semi-empirical dispersion correction and a vdW functional. We find that three-dimensional Pt clusters are more stable than the two-dimensional when interacting with the support, and that the difference between their stabilities increases with the system size. Also, the dispersion interactions are more pronounced as we increase the nanoparticle size, being essential to a reliable description of larger systems. We observe inter-atomic expansion (contraction) on the closest (farthest) Pt facets from the graphene sheet and charge redistribution with overall charge being transferred from the platinum clusters to the support. The Pt-Pt expansion, which is related to the charge transfer in the system, correlates with the adsorption energy per Pt atom in contact with the graphene. These, and other electronic and structural observations show that the effect of the support cannot be neglected. Our study provides for the first time, to the best of our knowledge, quantitative results on the non-trivial combination of size and support effects for nanoparticles sizes which are relevant to catalyst design.

7.
Mymensingh Med J ; 25(3): 500-5, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27612898

RESUMO

The meniscus is the most commonly injured structure in the knee joint. Carefully performed clinical examination can give better diagnosis of meniscal tear. The aim of this study was to find out the correlation between clinical and arthroscopic findings in meniscal tear of knee. This cross sectional observational study was conducted in the Department of Orthopaedic Surgery, BSMMU, Dhaka from July 2012 to June 2014. Thirty patients of meniscal tear were selected as per inclusion and exclusion criteria. After proper evaluation and clinical examination of these patient arthroscopic examinations was done under spinal anesthesia. A total number of 30 patients were recruited in this study. Twenty seven (90%) patients were male and only 3(10%) were female. Mean±SD of age was 26.00±5.55 and range was 17-34 years. Out of 30 patients 19(63.3%) had right knee affected and the rest 11(36.7%) had left knee affected. It was found from clinical diagnosis that most of the patients had MM injury (73.4%) and LM injury was in 26.6% patients. From arthroscopic diagnosis we found most of the patients had multiple types of injury (40.0%) followed by 26.7% patents had isolated MM injury, 16.6% patients had isolated LM injury, 10.0% patients had other injuries like ACL, PCL or MCL and rest 6.7% patients had no injury at all. Sensitivity, specificity, PPV, NPV and accuracy of clinical diagnosis in diagnosis of MM injury were 94.4%, 58.3%, 77.3%, 87.5% and 80.0% respectively. Sensitivity, specificity, PPV, NPV and accuracy of clinical diagnosis in diagnosis of LM injury were 85.7%, 91.3%, 75.0%, 95.5% and 90.0% respectively. Clinical evaluation may diagnose meniscal tear accurately.


Assuntos
Traumatismos do Joelho , Lesões do Menisco Tibial , Adulto , Artroscopia , Bangladesh , Estudos Transversais , Feminino , Humanos , Traumatismos do Joelho/diagnóstico por imagem , Articulação do Joelho , Imageamento por Ressonância Magnética , Masculino , Lesões do Menisco Tibial/diagnóstico por imagem , Adulto Jovem
8.
Br J Pharmacol ; 173(3): 484-96, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26493539

RESUMO

BACKGROUND AND PURPOSE: In the phase III clinical trial, RELAX-AHF, serelaxin caused rapid and long-lasting haemodynamic changes. However, the cellular mechanisms involved are unclear in humans. EXPERIMENTAL APPROACH: This study examined the effects of serelaxin in co-cultures of human primary endothelial cells (ECs) and smooth muscle cells (SMCs) on cAMP and cGMP signalling. KEY RESULTS: Stimulation of HUVECs or human coronary artery endothelial cells (HCAECs) with serelaxin, concentration-dependently increased cGMP accumulation in co-cultured SMCs to a greater extent than in monocultures of either cell type. This was not observed in human umbilical artery endothelial cells (HUAECs) that do not express the relaxin receptor, RXFP1. Treatment of ECs with l-N(G) -nitro arginine (NOARG; 30 µM, 30 min) inhibited serelaxin-mediated (30 nM) cGMP accumulation in HUVECs, HCAECs and co-cultured SMCs. In HCAECs, but not HUVECs, pre-incubation with indomethacin (30 µM, 30 min) also inhibited cGMP accumulation in SMCs. Pre-incubation of SMCs with the guanylate cyclase inhibitor ODQ (1 µM, 30 min) had no effect on serelaxin-mediated (30 nM) cGMP accumulation in HUVECs and HCAECs but inhibited cGMP accumulation in SMCs. Serelaxin stimulation of HCAECs, but not HUVECs, increased cAMP accumulation concentration-dependently in SMCs. Pre-incubation of HCAECs with indomethacin, but not l-NOARG, abolished cAMP accumulation in co-cultured SMCs, suggesting involvement of prostanoids. CONCLUSIONS AND IMPLICATIONS: In co-cultures, treatment of ECs with serelaxin caused marked cGMP accumulation in SMCs and with HCAEC also cAMP accumulation. Responses involved EC-derived NO and with HCAEC prostanoid production. Thus, serelaxin differentially modulates vascular tone in different vascular beds.


Assuntos
Vasos Coronários/citologia , Células Endoteliais/metabolismo , Miócitos de Músculo Liso/metabolismo , Relaxina/farmacologia , Artérias Umbilicais/citologia , Veias Umbilicais/citologia , Técnicas de Cocultura , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Humanos , Indometacina/farmacologia , Nitroarginina/farmacologia , Oxidiazóis/farmacologia , Quinoxalinas/farmacologia , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Peptídeos/metabolismo , Proteínas Recombinantes/farmacologia , Transdução de Sinais
9.
Br J Pharmacol ; 172(4): 1005-19, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25297987

RESUMO

BACKGROUND AND PURPOSE: In a recently conducted phase III clinical trial, RELAX-AHF, serelaxin infusion over 48 h improved short- and long-term clinical outcomes in patients with acute heart failure. In this study we used human primary cells from the umbilical vasculature to better understand the signalling mechanisms activated by serelaxin. EXPERIMENTAL APPROACH: We examined the acute effects of serelaxin on signal transduction mechanisms in primary human umbilical vascular cells and its chronic actions on markers of cardiovascular function and disease. KEY RESULTS: The RXFP1 receptor, the cognate serelaxin receptor, was expressed at the cell surface in HUVECs and human umbilical vein smooth muscle cells (HUVSMCs), human umbilical artery smooth muscle cells (HUASMCs) and human cardiac fibroblasts (HCFs), but not human umbilical artery endothelial cells. In HUVECs and HUVSMCs, serelaxin increased cAMP, cGMP accumulation and pERK1/2, and the concentration-response curves (CRCs) were bell-shaped. Similar bell-shaped CRCs for cGMP and pERK1/2 were observed in HCFs, whereas in HUASMCs, serelaxin increased cAMP, cGMP and pERK1/2 with sigmoidal CRCs. Gαi/o and lipid raft disruption, but not Gαs inhibition, altered the serelaxin CRC for cAMP and cGMP accumulation in HUVSMC but not HUASMC. Longer term serelaxin exposure increased the expression of neuronal NOS, VEGF, ETß receptors and MMPs (gelatinases) in RXFP1 receptor-expressing cells. CONCLUSIONS AND IMPLICATIONS: Serelaxin caused acute and chronic changes in human umbilical vascular cells that were cell background dependent. Bell-shaped CRCs that were observed only in venous cells and fibroblasts involved Gαi/o located within membrane lipid rafts.


Assuntos
Células Endoteliais/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Proteínas de Ligação ao GTP/metabolismo , Miócitos de Músculo Liso/efeitos dos fármacos , Relaxina/farmacologia , Células Cultivadas , Relação Dose-Resposta a Droga , Células Endoteliais/metabolismo , Fibroblastos/metabolismo , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Miócitos de Músculo Liso/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Receptor de Endotelina B/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Peptídeos/metabolismo , Proteínas Recombinantes/farmacologia , Transdução de Sinais , Artérias Umbilicais/citologia , Veias Umbilicais/citologia , Fator A de Crescimento do Endotélio Vascular/metabolismo
10.
Drug Alcohol Depend ; 140: 8-16, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24837581

RESUMO

BACKGROUND: Chronic alcohol intake produces multiple neuroadaptive changes, including up- and down-regulation of neuropeptides and receptors. There are widespread projections of relaxin-3 containing neurons to, and abundant relaxin family peptide 3 receptor (RXFP3) expression within, brain regions involved in modulating alcohol intake. Recently we demonstrated the involvement of relaxin-3/RXFP3 signalling in alcohol-seeking in rats; therefore in this study we examined whether relaxin-3 and/or RXFP3 expression were altered by chronic alcohol intake in alcohol-preferring iP rats. METHODS: Expression of relaxin-3 mRNA in the hindbrain nucleus incertus and RXFP3 radioligand binding levels in discrete forebrain regions were investigated following voluntary intake of alcohol or sucrose for 12 weeks, with a 2 day washout, using quantitative in situ hybridisation histochemistry and in vitro receptor autoradiography, respectively, in cohorts of adult, male iP rats. RESULTS: Levels of relaxin-3 mRNA in the hindbrain nucleus incertus were positively correlated with the level of intake of both alcohol (r(12)=0.59, p=0.03) and sucrose (r(7)=0.70, p=0.04) in iP rats. Dense binding of the RXFP3-selective radioligand, [(125)]-R3/I5, was detected in hypothalamic and extrahypothalamic sites, but no significant changes in the density of RXFP3 were observed in the brain regions quantified following chronic sucrose or ethanol intake. CONCLUSIONS: Our findings suggest high endogenous relaxin-3 expression may be associated with higher intake of rewarding substances, rather than its expression being regulated in response to their intake, consistent with an active role for the relaxin-3/RXFP3 system in modulating ingestive and alcohol-related behaviours.


Assuntos
Consumo de Bebidas Alcoólicas/genética , Ingestão de Alimentos/genética , RNA Mensageiro/biossíntese , Núcleos da Rafe/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores de Peptídeos/genética , Consumo de Bebidas Alcoólicas/psicologia , Animais , Ingestão de Líquidos/fisiologia , Masculino , Ratos , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Peptídeos/metabolismo , Rombencéfalo/efeitos dos fármacos , Rombencéfalo/metabolismo , Sacarose/farmacologia
11.
Br J Pharmacol ; 171(11): 2827-41, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24641548

RESUMO

BACKGROUND AND PURPOSE: Relaxin family peptide receptor 3 (RXFP3) is expressed in brain areas important for processing sensory information and feeding, suggesting that it may be a target for anti-anxiety and anti-obesity drugs. We examined the effects of H3 relaxin, the biased agonist H2 relaxin and the antagonist, R3(BΔ23-27)R/I5, on RXFP3 signalling to establish their suitability as tools to assess the physiological roles of RXFP3. EXPERIMENTAL APPROACH: The signalling profile of the RXFP3 ligands was determined using reporter gene assays, multiplexed signalling assays and direct examination of receptor-G protein and receptor-ß-arrestin interactions using BRET. KEY RESULTS: H2 relaxin activated p38MAPK and ERK1/2 with lower efficacy than H3 relaxin, but had similar efficacy for JNK1/2 phosphorylation. H2 or H3 relaxin activation of p38MAPK, JNK1/2 or ERK1/2 involved Pertussis toxin-sensitive G-proteins. R3(BΔ23-27)R/I5 blocked H3 relaxin AP-1 reporter gene activation, but not H2 relaxin AP-1 activation or H3 relaxin NF-κB activation. R3(BΔ23-27)R/I5 activated the SRE reporter, but did not inhibit either H2 or H3 relaxin SRE activation. R3(BΔ23-27)R/I5 blocked H3 relaxin-stimulated p38MAPK and ERK1/2 phosphorylation, but was a weak partial agonist for p38MAPK and ERK1/2 signalling. p38MAPK activation by R3(BΔ23-27)R/I5 was G protein-independent. H3 relaxin-activated RXFP3 interacts with Gαi2 , Gαi3 , Gαo A and Gαo B whereas H2 relaxin or R3(BΔ23-27)R/I5 induce interactions only with Gαi2 or Gαo B . Only H3 relaxin promoted RXFP3/ß-arrestin interactions that were blocked by R3(BΔ23-27)R/I5. CONCLUSION AND IMPLICATIONS: Understanding signalling profile of drugs acting at RXFP3 is essential for development of therapies targeting this receptor.


Assuntos
Receptores Acoplados a Proteínas G/metabolismo , Relaxina/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Células CHO , Cricetulus , AMP Cíclico/metabolismo , Endopeptidases/genética , Endopeptidases/metabolismo , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/genética , Receptores Acoplados a Proteínas G/genética , Elemento de Resposta Sérica/genética , Fator de Transcrição AP-1/genética
12.
Drug Res (Stuttg) ; 64(7): 353-7, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24227475

RESUMO

Serum lipid levels are greatly controlled by genetic and environmental factors. When investigating the relationship between lipid disturbances and hypertension it is necessary to use local data on blood lipid profile in each region. Unfortunately, there is no literature reporting the lipid profile in hypertensive patients in coastal region of Bangladesh. The present study was conducted as a case-control study with 100 hypertensive patients as cases and equal number of normotensive individuals as controls. Socio-demographic, anthropometric and clinical data of both patients and controls were collected. Serum lipid parameters were analyzed biochemically. Independent sample t-test, Chi-Square test and Pearson's correlation test were done for the statistical analysis using the statistical software package SPSS. Our study found that serum total cholesterol (TC), triglyceride (TG), LDL, VLDL, TC/HDL, LDL/HDL were significantly higher (p<0.05) whereas the level of HDL cholesterol was significantly lower in hypertensive patients as compared to control subjects (p<0.05). Pearson's correlation analysis reveals that HDL cholesterol was inversely correlated with systolic and diastolic blood pressure in both patient and control groups. But serum TC, TG, LDL and HDL cholesterol were directly correlated with systolic and diastolic blood pressure in both groups. This study explored that hypertensive patients have higher level of TC, TG, LDL and VLDL cholesterol but lower level of HDL cholesterol than the normotensive subjects. Routine investigation of lipid profile in hypertensive patients may help to prevent further aggravation and risks of coronary artery diseases.


Assuntos
Hipertensão/sangue , Lipídeos/sangue , Adulto , Bangladesh , Pressão Sanguínea/fisiologia , Estudos de Casos e Controles , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Feminino , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Triglicerídeos/sangue
13.
Drug Res (Stuttg) ; 63(8): 424-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23670827

RESUMO

There are sufficient experimental evidences to establish the relationship between the elevated level of malondealdehyde (MDA)-the lipid peroxidation product and depleted level of antioxidants (Vitamin A, E, C and glutathione) in several psychiatric disorders. But previously no study was carried out to determine these components in panic disorder (PD) patients of Bangladesh. This study was conducted to assess the serum concentration of antioxidant vitamins, MDA and glutathione in 54 panic disorder patients and 52 healthy volunteers. Patients were recruited from Bangabandhu Sheikh Mujib Medical University, Bangladesh by random sampling. Serum level of MDA, glutathione and vitamin C were determined by UV spectrophotometric method whereas Vitamins A and E were detected by RP-HPLC method. Data were analyzed by independent t test and Pearson's correlation analysis. It had been found that the PD patients had low level of antioxidants like vitamin A (p=0.041) and vitamin E (p=0.018) than the healthy controls whereas the change of vitamin C is not significant. It had been found that the MDA content was significantly higher (p<0.05) in PD patients than that of controls. There was no significant difference for the glutathione content between the 2 groups. Pearson's correlation coefficient suggested that there were significant negative correlation between the glutathione level and vitamin C (p=0.013) and a positive correlation between the vitamin E and vitamin A (p=0.020) in patient group. Our study reveals that panic disorder patients have considerably higher level of MDA, lower level of antioxidant vitamins and glutathione than the healthy control subjects.


Assuntos
Antioxidantes/análise , Ácido Ascórbico/sangue , Glutationa/sangue , Malondialdeído/sangue , Transtorno de Pânico/metabolismo , Vitamina E/sangue , Adolescente , Adulto , Idoso , Humanos , Pessoa de Meia-Idade
14.
Drug Res (Stuttg) ; 63(5): 217-23, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23526242

RESUMO

Resistant hypertension (RH) is defined as failure to achieve goal blood pressure while receiving a 3 drug regimen at optimal doses that includes a diuretic. The exact prevalence of resistant hypertension is unknown which may vary from 5% to 50%. Patient or clinician-related factors contributing to resistant hypertension include patient's non-adherence to antihypertensive therapy, White-coat effect and pseudo-hypertension and life style factors (Obesity, alcohol, smoking, dietary sodium etc). Several drugs may induce pre-existing hypertension where non-steroidal anti-inflammatory drugs are usually the most common due to their frequent use; whereas oral contraceptives, sympathomimetics (decongestants, anorectics), adrenal steroids and antineoplastic drugs targeting the vascular endothelial growth factor (VEGF) pathway has a good deal of contribution to resistant hypertension. Most common secondary causes of resistant hypertension are obstructive sleep apnea, renal artery stenosis, renal parenchymal disease, and primary aldosteronism while some uncommon causes such as pheochromocytoma, Cushing's disease, thyroid and parathyroid dysfunction; and aortic coarctation also contribute to resistant hypertension. Both pharmacological and non-pharmacological treatments are available for the management of resistant hypertension. This article reviews the prevalence, symptoms, causes and treatment of resistant hypertension.


Assuntos
Hipertensão/etiologia , Hipertensão/terapia , Resistência a Medicamentos , Humanos , Hipertensão/epidemiologia , Estilo de Vida , Prevalência
15.
Animal ; 6(8): 1231-6, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23217226

RESUMO

The objective of the study was to assess the post-weaning growth response of Sahiwal calves reared on four different pre-weaning dietary regimens. The four diets were: (a) whole cow's milk, starter ration (SR; CP = 20%, total digestible nutrients (TDN) = 72%) and Berseem hay (H; Egyptian clover; CP = 21%, TDN = 63%); (b) whole cow's milk + H; (c) milk replacer (MR; reconstituted to supplier specification; Sprayfo®) + SR + H; and (d) MR + H. The protein and fat percentages of reconstituted MR were 2.22 and 1.84, respectively. Milk or MR were fed at the rate of 10% of the calves' body weight (BW) until 56 days of age, and then withdrawn gradually until weaned completely by 84 days of age. The average initial BW of calves in groups A, B, C and D were 56.3 ± 1.0, 47.5 ± 1.0, 40.4 ± 1.0 and 30.3 ± 1.0 kg, respectively. Initially, there were 12 calves in each group with six of each sex; however, one male calf died from each of groups B and C and were not replaced. During the post-weaning period, 13 to 24 weeks, the calves were fed a single total mixed ration ad libitum based on maize, canola meal, wheat straw and molasses containing 16% CP and 70% TDN. Daily feed intake and weekly BW gains were recorded. The data were analyzed by MIXED model analysis procedures using the statistical program SAS. The intake of calves as percent of their BW, feed conversion ratio and cost per kg of BW gain were not different (P > 0.05) across treatments. The daily gain at 24 weeks of age for the pre-weaning treatments A, B, C and D were 746 ± 33, 660 ± 33, 654 ± 33 and 527 ± 33 g/day and the final liveweights of calves were 119 ± 4.2, 102 ± 4.2, 95 ± 4.2 and 75 ± 4.2 kg, respectively. Gains were influenced significantly (P < 0.05) by pre-weaning treatments. The calves fed MR and H only during the pre-weaning period were unable to catch up post weaning with calves on other dietary treatments. The calves fed whole milk from birth at the rate of 10% of liveweight together with concentrates had higher weaning weight and superior growth rate post weaning as well. Thus, pre-weaning feeding was important for higher weaning weights and superior growth rates post weaning.


Assuntos
Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Bovinos/crescimento & desenvolvimento , Leite/química , Fatores Etários , Animais , Ingestão de Alimentos/fisiologia , Paquistão , Desmame , Ganho de Peso/fisiologia
16.
Animal ; 6(6): 994-1004, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22558970

RESUMO

The high prevalence of anthelmintic-resistant gastrointestinal nematodes (GINs) throughout the world has led to the need for alternative worm control strategies. One of the possible substitutes to reduce the problems of drug resistance and residue is the evaluation/breeding of small ruminants for greater resistance to the GINs (organically produced), which in turn would be a helpful tool to predict the performance of an animal. At present, the existing diversity in the genetic potential to resist/tolerate GINs infection both within and between breeds has been validated. Successful selection of animals to define the genotype and identified resistance is related to the employed markers. A number of phenotypic traits such as faecal egg count (FEC), worm burden, serum antibodies, peripheral eosinophilia, packed cell volume, live weight, serum protein and albumin concentrations have been used for this purpose both in natural and artificial infections. Relatively resistant/tolerant animals have also been found to have mastocytosis, globule leucocytes, high levels of histamine and immunoglobulin (Ig) A and IgE concentrations. Of these traits, the principal and most practical measurement used to assess resistance status in animals undergoing similar parasite challenges is FEC. FEC has a positive/negative correlation with other biochemical, cellular and immunological parameters; however, the reliability of individual trial is often questioned and valuable information regarding the genetic makeup can be obtained from pooled data of a large number of trials and parameters. This paper covers all the aspects reported in the literature on various parameters considered to evaluate the resistance status of a range of small ruminant breeds.


Assuntos
Criação de Animais Domésticos/métodos , Gastroenteropatias/veterinária , Doenças das Cabras/imunologia , Imunidade Inata , Nematoides/fisiologia , Infecções por Nematoides/veterinária , Doenças dos Ovinos/imunologia , Animais , Biomarcadores/análise , Biomarcadores/sangue , Fezes/parasitologia , Feminino , Gastroenteropatias/sangue , Gastroenteropatias/imunologia , Gastroenteropatias/parasitologia , Doenças das Cabras/sangue , Doenças das Cabras/parasitologia , Cabras , Masculino , Infecções por Nematoides/sangue , Infecções por Nematoides/imunologia , Infecções por Nematoides/parasitologia , Contagem de Ovos de Parasitas/veterinária , Ovinos , Doenças dos Ovinos/sangue , Doenças dos Ovinos/parasitologia
17.
Parasite ; 19(1): 53-61, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22314240

RESUMO

A questionnaire survey was conducted to determine the worm control practices and anthelmintic usage of 150 key respondents involved in sheep and goat production in the arid Thal area of Pakistan. The information was collected by visiting farms, and interviewing the key respondents which included veterinary officers (n = 15), veterinary assistants (n = 51), traditional practitioners (n = 24), and small and large scale sheep/goat farm herders and owners (n = 60). Among all interviewed animal healthcare providers, the veterinary officers had the highest level of awareness of parasitic infection and advocated the use of modern available anthelmintics according to the predefined schedule. The farmers on the other hand, had the lowest level of knowledge about parasitic infections. They used modern anthelmintics at low frequencies (every six months) following an unusual practice of diluting the medicine. Veterinary assistants had a medium level of awareness about the parasitic infections using anthelmintic treatments when they deemed necessary rather than following a predefined treatment schedule. Traditional practitioners were also aware of parasitic infections and used traditional anthelmintics or a combination of the traditional and modern anthelmintics. The animal health providers had a different awareness and knowledge of parasitic infections which resulted in contrasting proposals for its' control. The farmers used worm control measures in accordance with their own views and those of animal healthcare advisors, combining modern and traditional treatments. This study provides the first insight into the differing views of those animal healthcare providers who form the basis for effective parasitic control within the sheep and goat industry of an arid region.


Assuntos
Criação de Animais Domésticos/métodos , Doenças das Cabras/prevenção & controle , Helmintíase Animal/prevenção & controle , Enteropatias Parasitárias/veterinária , Doenças dos Ovinos/prevenção & controle , Agricultura , Técnicos em Manejo de Animais , Animais , Anti-Helmínticos/uso terapêutico , Clima Desértico , Escolaridade , Doenças das Cabras/parasitologia , Cabras , Conhecimentos, Atitudes e Prática em Saúde , Abrigo para Animais , Entrevistas como Assunto , Enteropatias Parasitárias/prevenção & controle , Paquistão , Ovinos , Doenças dos Ovinos/parasitologia , Inquéritos e Questionários , Médicos Veterinários
18.
Mymensingh Med J ; 21(1): 175-8, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22314478

RESUMO

A 28 years young lady admitted to National Institute of Diseases of Chest and Hospital (NIDCH), Dhaka with the complaints of respiratory distress and cough for 2 months. She was in her last trimester of first pregnancy when she becomes dyspneic on exertion and at night. Gradually it increases in time and she become unable to walk when she consulted with specialists in Barisal. She was examined clinically and radiographically and found some opacity on both lung fields. She was on several antibiotics, but got no improvement. In the meantime, an emergency caesarean section was done to have a healthy baby and patient came to NIDCH for this unexplained breathlessness and cough. She was severely dyspneic, tachypnoic, cyanosed. There were bilateral coarse crepitations, bilateral opacities predominantly on both lower and middle zones of both lungs obscuring costo-phrenic angles on chest X-rays. CT scan of chest shows bilateral reticulo-nodular shadows with a homogenous opacity on right lower lung which enhances after contrast scanning. A CT guided FNAC was done from that opacity which revealed a papillary adeno-carcinoma with psammoma bodies on cytopathological study. Thereafter, to explore the primary site, thyroid gland, abdominal organs was assessed adequately and only positive finding was raised CA-125 (706 IU/ml) which was consistent with ovarian cancer. In this way, a primary ovarian carcinoma in a pregnant young lady with normal sized ovary that metastasizes to lung causing bilateral pleural effusion and lymphangitis carcinomatosa was explored. This was an unusual presentation of ovarian papillary adeno-carcinoma with cough and breathlessness at the last trimester of pregnancy in absence of any abdominal mass.


Assuntos
Adenocarcinoma Papilar/secundário , Neoplasias Pulmonares/secundário , Neoplasias Ovarianas/patologia , Complicações Neoplásicas na Gravidez/patologia , Adenocarcinoma Papilar/complicações , Adulto , Feminino , Humanos , Neoplasias Pulmonares/complicações , Linfangite/etiologia , Derrame Pleural Maligno/etiologia , Gravidez , Terceiro Trimestre da Gravidez
20.
Br J Pharmacol ; 162(5): 1012-28, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20955367

RESUMO

BACKGROUND AND PURPOSE: While maintaining cardiac performance, chronic ß-adrenoceptor activation eventually exacerbates the progression of cardiac remodelling and failure. We examined the adverse signalling pathways mediated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and reactive oxygen species (ROS) after chronic ß2-adrenoceptor activation. EXPERIMENTAL APPROACH: Mice with transgenic ß2-adrenoceptor overexpression (ß2-TG) and non-transgenic littermates were either untreated or treated with an antioxidant (N-acetylcysteine, NAC) or NADPH oxidase inhibitors (apocynin, diphenyliodonium). Levels of ROS, phosphorylated p38 mitogen-activated protein kinase (MAPK), pro-inflammatory cytokines and collagen content in the left ventricle (LV) and LV function were measured and compared. KEY RESULTS: ß2-TG mice showed increased ROS production, phosphorylation of p38 MAPK and heat shock protein 27 (HSP27), expression of pro-inflammatory cytokines and collagen, and progressive ventricular dysfunction. ß2-adrenoceptor stimulation similarly increased ROS production and phosphorylation of p38 MAPK and HSP27 in cultured cardiomyocytes. Treatment with apocynin, diphenyliodonium or NAC reduced phosphorylation of p38 MAPK and HSP27 in both cultured cardiomyocytes and the LV of ß2-TG mice. NAC treatment (500 mg·kg⁻¹ ·day⁻¹) for 2 weeks eliminated the up-regulated expression of pro-inflammatory cytokines and collagen in the LV of ß2-TG mice. Chronic NAC treatment to ß2-TG mice from 7 to 10 months of age largely prevented progression of ventricular dilatation, preserved contractile function (fractional shortening 37 ± 5% vs. 25 ± 3%, ejection fraction 52 ± 5% vs. 32 ± 4%, both P < 0.05), reduced cardiac fibrosis and suppressed matrix metalloproteinase activity. CONCLUSION AND IMPLICATIONS: ß2-adrenoceptor stimulation provoked NADPH oxidase-derived ROS production in the heart. Elevated ROS activated p38 MAPK and contributed significantly to cardiac inflammation, remodelling and failure.


Assuntos
Cardiomiopatias/etiologia , Cardiomiopatias/metabolismo , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/metabolismo , Miocárdio/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Acetilcisteína/farmacologia , Animais , Antioxidantes/farmacologia , Cardiomiopatias/tratamento farmacológico , Colágeno/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Proteínas de Choque Térmico HSP27/metabolismo , Insuficiência Cardíaca/tratamento farmacológico , Mediadores da Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Miócitos Cardíacos/metabolismo , NADPH Oxidases/antagonistas & inibidores , NADPH Oxidases/metabolismo , Estresse Oxidativo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Receptores Adrenérgicos beta 2/genética , Transdução de Sinais , Remodelação Ventricular/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
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