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1.
Chemphyschem ; : e202400672, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39267598

RESUMO

Bacteriorhodopsin (bR) of purple membrane (PM) has increasing technical interests, particularly in photonic devices and bioelectronics. The present work has concerned with monitoring the temperature dependence of passive electric responses in-plane and out-of-plane of the membranes. Based on thermal properties observed orthogonally here for PM, a high-temperature intermediate of bR has been suggested to populate at around 60 °C, which may be ascribed to a molten globule-like state. This intermediate has been found to be enclosed between two reversible thermal transitions for PM. Large-scale turnover in the energy of activation, for these two thermal transitions, occurs steeply at such state at 60 °C, above which does bR reverse the sign of dielectric anisotropy (i.e. crossover) provided the operating frequency should be above the crossover frequency, at which the reversal occurs. No such crossover was found to occur below the crossover frequency, even above the crossover temperature (i.e. 60 °C). Likewise, no such crossover was found to occur below the crossover temperature, even above the crossover frequency. Relying on this reasoning, a logic gate operation may be declared implicating bR for bioelectronics and sense technological relevance. In addition, the results specify "dual frequency" as well as "dual temperature" characteristics to bacteriorhodopsin.

2.
N Engl J Med ; 382(3): 256-265, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-31940699

RESUMO

Deficiency of ubiquitin-specific peptidase 18 (USP18) is a severe type I interferonopathy. USP18 down-regulates type I interferon signaling by blocking the access of Janus-associated kinase 1 (JAK1) to the type I interferon receptor. The absence of USP18 results in unmitigated interferon-mediated inflammation and is lethal during the perinatal period. We describe a neonate who presented with hydrocephalus, necrotizing cellulitis, systemic inflammation, and respiratory failure. Exome sequencing identified a homozygous mutation at an essential splice site on USP18. The encoded protein was expressed but devoid of negative regulatory ability. Treatment with ruxolitinib was followed by a prompt and sustained recovery. (Funded by King Saud University and others.).


Assuntos
Doenças Hereditárias Autoinflamatórias/tratamento farmacológico , Interferons/metabolismo , Interleucinas/metabolismo , Janus Quinase 1/antagonistas & inibidores , Inibidores de Janus Quinases/uso terapêutico , Mutação com Perda de Função , Pirazóis/uso terapêutico , Ubiquitina Tiolesterase/deficiência , Homozigoto , Humanos , Hidrocefalia/genética , Recém-Nascido , Masculino , Nitrilas , Pirimidinas , Receptores de Interferon/metabolismo , Indução de Remissão , Choque Séptico/genética , Transdução de Sinais/genética , Ubiquitina Tiolesterase/genética , Sequenciamento do Exoma
3.
Anal Chem ; 92(11): 7947-7954, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32383384

RESUMO

Several reports in the literature deal with the modification of glassy carbon electrode (GCE) surface via electropolymerization of some organic monomers, particularly p-aminobenzenesulfonic acid (p-ABSA) and l-cysteine using intensive oxidative conditions, and attributed the improved electrocatalytic activities toward various analytes to the formation of the electropolymerized layer. What is the real cause for this improvement in electrocatalytic activity? Is it because of the electrochemical activation process of GCE or electropolymerization? Combining a set of surface and electrochemical characterization techniques, we first showed that the electrochemical peaks previously assigned in many reports to electropolymerization processes at the surface of GCE correspond to electrochemical activation of the GCE surface. We further demonstrated that the anodization of GCE at high voltage causes activation of its surface and the formation of surface functional groups (SFGs). In fact, those SFGs are found to be the main reason for the enhancement in electrocatalytic activity of the activated GCE (AGCE). The surface features of the modified electrodes were characterized by Raman spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The electrochemical behavior was investigated using cyclic voltammetry (CV). The analytical performance of AGCE toward dopamine (DA) was assessed using differential pulse voltammetry (DPV). As compared to the previously reported dopamine electrochemical sensors assuming such electropolymerization processes, the AGCE showed analytical performance practically similar to that of these sensors. This further confirms that the enhancement in electrocatalytic activity is due to the electrochemical activation of the GCE surface.

4.
Diabetes Metab Res Rev ; 36(5): e3299, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32043290

RESUMO

BACKGROUND AND OBJECTIVE: Diabetic nephropathy (DN) is the most common cause of end stage renal failure or even death among patients with type 2 diabetes mellitus. Genetic predisposition is widely studied among these patients to identify manageable aspects of the disease pathogenesis. This study was carried out to test the association of engulfment and cell motility 1 (ELMO1) gene polymorphism with DN among Egyptians. ELMO1 is required for phagocytosis of apoptotic cells and cell motility. METHODS: This case-control study was conducted on type 2 diabetic patients who attended Suez Canal University Hospital, Egypt, between November 2016 and October 2017. Peripheral blood was collected from 200 diabetic patients (without nephropathy), 200 patients with DN, and 100 healthy controls for DNA extraction. The single nucleotide polymorphism of ELMO1 (rs741301) was genotyped using real-time polymerase chain reaction and the allele discrimination technique. RESULTS: GG genotype was significantly associated with DN (odds ratio [OR] = 2.7; 95% confidence interval [CI]: 1.4-5.3) (P = .016). The OR for the high-risk allele (G) was 1.9 with 95% CI from 1.5 to 2.9 (P < .001). CONCLUSION: ELMO1 gene (rs741301) polymorphism is a candidate variant in the predisposition to DN.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Biomarcadores/análise , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/etiologia , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Glicemia/análise , Nefropatias Diabéticas/epidemiologia , Nefropatias Diabéticas/patologia , Egito/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
5.
J Intensive Care Med ; 34(6): 503-510, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28403662

RESUMO

OBJECTIVES: Study of inflammatory biomarkers which may aid in early detection of ventilator-associated pneumonia (VAP) in children and predicting their outcome. PATIENTS: Thirty-five children, aged 2 months to 13 years, needed mechanical ventilation (MV) for more than 48 hours due to causes other than pneumonia. METHODS: Measurement of serum amyloid A (SAA) protein, soluble intercellular adhesion molecule 1 (sICAM-1), and C-reactive protein (CRP), modified clinical pulmonary infection score (CPIS) and performing culture of endotracheal aspirate at the start and on the third day of MV. RESULTS: Ventilator-associated pneumonia was diagnosed by CPIS in 6 (17.1%) of 35 patients. On the third day of MV, there was a significant increase in serum mean levels of SAA, sICAM-1, and CRP in comparison to the start of MV ( P = .005, .004, and .01, respectively). Three (50%) of 6 patients with VAP died, while 4 (14.28%) of 28 patients without VAP died. The sensitivity of serum SAA, sICAM-1, and CPIS were 100% for predicting VAP, while specificity was highest for CPIS (96.55%) followed by SAA (93.1%). Combination of CPIS and SAA increased the specificity to 100%. For predicting nonsurvival, serum SAA and sICAM-1 had a sensitivity of 100% and a specificity of 92.86% and 89.29%, respectively. CONCLUSION: Serum amyloid A and sICAM-1 may be considered as reliable markers for detection of VAP. Combination of serum SAA with CPIS increased the specificity to 100%. Measurement of SAA in patients with VAP also had a good predictive value for nonsurvival in such patients.


Assuntos
Molécula 1 de Adesão Intercelular/sangue , Pneumonia Associada à Ventilação Mecânica/sangue , Respiração Artificial/efeitos adversos , Proteína Amiloide A Sérica/metabolismo , Biomarcadores/sangue , Criança , Pré-Escolar , Egito , Humanos , Lactente , Unidades de Terapia Intensiva , Masculino , Pneumonia Associada à Ventilação Mecânica/fisiopatologia , Pneumonia Associada à Ventilação Mecânica/terapia , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos
6.
Biochem Genet ; 57(1): 170-191, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30074102

RESUMO

Egypt is a transcontinental country containing substantial ethnic, cultural, and linguistic diversity among its people. This study was conducted to investigate the genetic variation at 15 AmpFlSTR Identifiler short tandem repeat (STR) loci, D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, and FGA, within and between seven Egyptian populations. Samples of 814 unrelated individuals from Northern Coast, Delta, Greater Cairo, Canal governorates, Northern Upper Egypt, Southern Upper Egypt, and Sinai were investigated. All loci were highly polymorphic in all sample populations. The data were analyzed to give information on allele frequencies and other population statistical parameters. After applying Bonferroni correction, the agreement with Hardy-Weinberg equilibrium (HWE) was confirmed for all loci (exact test), and for all loci with the exception of D3S1358, D19S433, and D18S51 (X2 test). The levels of genetic differentiation and the genetic relationships among populations were evaluated by coefficient of genetic differentiation (FST), AMOVA, and genetic distance of Nei. The most differentiated populations were found between Sinai and Southern Upper Egypt. These two populations showed the lowest within-population variation, whereas the population of Greater Cairo showed the highest within-population variation as indicated by the fixation index FIS. The varying levels of genetic relatedness among the populations in relation to their geographical distribution were analyzed using Mantel test. The results demonstrated that the effectiveness of STR markers enhances their value for identifying the genetic variation within and between Egyptian populations.


Assuntos
Loci Gênicos/genética , Variação Genética , Repetições de Microssatélites/genética , Egito , Humanos
7.
Neurosciences (Riyadh) ; 24(4): 257-263, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31872803

RESUMO

OBJECTIVE: To review the experience of 2 tertiary centers in Saudi Arabia with intracranial hypertension (IH) in the pediatric population. METHODS: We retrospectively reviewed and analyzed pediatric patients diagnosed with IH from June 2002 to May 2017 in 2 institutes. RESULTS: We identified 53 patients (30 females and 23 males) with a mean age of 7 years at the time of presentation. Among them, 41 patients were younger than 12 years, and 12 were older. Obese and overweight patients constituted 27.00% (n = 14) of all cases, 8 (66.7%) of whom were older than 12 years. The most common presenting feature was papilledema followed by headache. Vitamin D deficiency, which constituted the most common associated condition, was identified in 12 (22.6%) patients. Acetazolamide was the treatment option in 98.11% of patients, and only 5.7% underwent surgical interventions. The length of follow-up ranged from 6 months to 8 years. CONCLUSION: Intracranial hypertension is rare in children and commonly seen in overweight females older than 12 years similar to adults. Patients younger than 12 years tend to develop secondary IH. More studies are needed to characterize the clinical presentation and guide the management plan.


Assuntos
Cefaleia/epidemiologia , Hipertensão Intracraniana/complicações , Obesidade/epidemiologia , Papiledema/epidemiologia , Deficiência de Vitamina D/epidemiologia , Acetazolamida/uso terapêutico , Criança , Pré-Escolar , Diuréticos/uso terapêutico , Feminino , Hospitais Pediátricos/estatística & dados numéricos , Humanos , Lactente , Hipertensão Intracraniana/tratamento farmacológico , Hipertensão Intracraniana/epidemiologia , Hipertensão Intracraniana/patologia , Masculino , Arábia Saudita , Centros de Atenção Terciária/estatística & dados numéricos
8.
J Pathol ; 231(3): 290-300, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24037780

RESUMO

'Oxidative stress' is a term defining states of elevated reactive oxygen species (ROS) levels. Normally, ROS control several physiological processes, such as host defence, biosynthesis of hormones, fertilization and cellular signalling. However, oxidative stress has been involved in different pathologies, including metabolic syndrome and numerous cardiovascular diseases. A major source of ROS involved in both metabolic syndrome and cardiovascular pathophysiology is the NADPH oxidase (NOX) family of enzymes. NOX is a multi-component enzyme complex that consists of membrane-bound cytochrome b-558, which is a heterodimer of gp91phox and p22phox, cytosolic regulatory subunits p47phox and p67phox, and the small GTP-binding protein Rac1. Rac1 plays many important biological functions in cells, but perhaps the most unique function of Rac1 is its ability to bind and activate the NOX complex. Furthermore, Rac1 has been reported to be a key regulator of oxidative stress through its co-regulatory effects on both nitric oxide (NO) synthase and NOX. Therefore, the main goal of this review is to give a brief outline about the important role of the Rac1-NOX axis in the pathophysiology of both metabolic syndrome and cardiovascular disease.


Assuntos
Doenças Cardiovasculares/enzimologia , Síndrome Metabólica/enzimologia , NADPH Oxidases/metabolismo , Estresse Oxidativo , Proteínas rac de Ligação ao GTP/metabolismo , Animais , Antioxidantes/uso terapêutico , Fármacos Cardiovasculares/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Humanos , Síndrome Metabólica/tratamento farmacológico , NADPH Oxidases/antagonistas & inibidores , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais , Proteínas rac de Ligação ao GTP/antagonistas & inibidores , Proteínas rac1 de Ligação ao GTP/metabolismo
9.
J Pediatr Endocrinol Metab ; 37(1): 21-26, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-37966142

RESUMO

OBJECTIVES: This study was conducted to study the expression of both microRNA-29a and microRNA-122, and serum levels of sestrin-2, interleukin-6 (IL-6), and other inflammatory markers among obese children with/and without diabetes mellitus. METHODS: One hundred obese children with diabetes in addition to 100 age- and sex-matched obese children without diabetes, and 100 age- and sex-matched apparently healthy children were included in the study. Expressions of both microRNA-29a and microRNA-122, and serum levels of sestrin-2, IL-6, tumor necrosis factor-α (TNF-α), and high sensitive-CRP (hsCRP) were measured for all included study populations. RESULTS: Study results showed that the expressions of both microRNA-29a and microRNA-122, serum levels of IL-6, TNF-α, and hsCRP were significantly higher among obese children with diabetes in comparison to both obese children without diabetes and healthy children. In contrast, serum sestrin level was significantly low among obese children with diabetes in comparison to the other study populations. Expressions of both microRNA-29a and microRNA-122 were correlated with waist circumference, BMI, total cholesterol, triglycerides, LDL-cholesterol, HbA1c, c-peptide, glucose, insulin, homeostatic model assessment-insulin resistance (HOMA-IR), IL-6, hsCRP, and TNF-α among obese children with diabetes. However, serum sestrin-2 level was correlated inversely with these parameters. Higher expressions of both microRNA-29a and microRNA-122 among obese children either with or without diabetes mellitus (DM) can suggest their roles in the development of obesity among children. CONCLUSIONS: The study results can hypothesize that down-regulation of these micro-RNAs may solve this health problem with its sequelae, a hypothesis that needs more studies.


Assuntos
Diabetes Mellitus , Resistência à Insulina , MicroRNAs , Obesidade Infantil , Criança , Humanos , Glicemia , Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Colesterol , Interleucina-6 , MicroRNAs/genética , Obesidade Infantil/complicações , Obesidade Infantil/genética , Sestrinas , Fator de Necrose Tumoral alfa
10.
Am J Physiol Heart Circ Physiol ; 304(2): H294-302, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23161879

RESUMO

The GTP-binding protein Rac regulates diverse cellular functions including activation of NADPH oxidase, a major source of superoxide production (O(2)(·-)). Rac1-mediated NADPH oxidase activation is increased after myocardial infarction (MI) and heart failure both in animals and humans; however, the impact of increased myocardial Rac on impending ischemia-reperfusion (I/R) is unknown. A novel transgenic mouse model with cardiac-specific overexpression of constitutively active mutant form of Zea maize Rac D (ZmRacD) gene has been reported with increased myocardial Rac-GTPase activity and O(2)(·-) generation. The goal of the present study was to determine signaling pathways related to increased myocardial ZmRacD and to what extent hearts with increased ZmRacD proteins are susceptible to I/R injury. The effect of myocardial I/R was examined in young adult wild-type (WT) and ZmRacD transgenic (TG) mice. In vitro reversible myocardial I/R for postischemic cardiac function and in vivo regional myocardial I/R for MI were performed. Following 20-min global ischemia and 45-min reperfusion, postischemic cardiac contractile function and heart rate were significantly reduced in TG hearts compared with WT hearts. Importantly, acute regional myocardial I/R (30-min ischemia and 24-h reperfusion) caused significantly larger MI in TG mice compared with WT mice. Western blot analysis of cardiac homogenates revealed that increased myocardial ZmRacD gene expression is associated with concomitant increased levels of NADPH oxidase subunit gp91(phox), O(2)(·-), and P(21)-activated kinase. Thus these findings provide direct evidence that increased levels of active myocardial Rac renders the heart susceptible to increased postischemic contractile dysfunction and MI following acute I/R.


Assuntos
Traumatismo por Reperfusão Miocárdica/enzimologia , Miocárdio Atordoado/enzimologia , Miócitos Cardíacos/enzimologia , Proteínas rac de Ligação ao GTP/metabolismo , Animais , Western Blotting , Modelos Animais de Doenças , Genótipo , Frequência Cardíaca , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Contração Miocárdica , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio Atordoado/genética , Miocárdio Atordoado/patologia , Miocárdio Atordoado/fisiopatologia , Miócitos Cardíacos/patologia , NADPH Oxidase 2 , NADPH Oxidases/metabolismo , Fenótipo , Transdução de Sinais , Superóxidos/metabolismo , Fatores de Tempo , Regulação para Cima , Quinases Ativadas por p21/metabolismo , Proteínas rac de Ligação ao GTP/genética
11.
Am J Med Genet A ; 161A(6): 1207-13, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23633300

RESUMO

Genetic factors represent an important etiologic group in the causation of intellectual disability. We describe a Saudi Arabian family with closley related parents in which four of six children were affected by a congenital cognitive disturbance. The four individuals (aged 18, 16, 13, and 2 years when last examined) had motor and cognitive delay with seizures in early childhood, and three of the four (sparing only the youngest child) had progressive, severe cognitive decline with spasticity. Two affected children had ocular malformations, and the three older children had progressive visual loss. The youngest had normal globes with good functional vision when last examined but exhibited the oculodigital sign, which may signify a subclinical visual deficit. A potentially deleterious nucleotide change (c.1A>G; p.Met1Val) in the C12orf57 gene was homozygous in all affected individuals, heterozygous in the parents, and absent in an unaffected sibling and >350 normal individuals. This gene has no known function. This family manifests a autosomal recessive syndrome with some phenotypic variability that includes abnormal development of brain and eyes, delayed cognitive and motor milestones, seizures, and a severe cognitive and visual decline that is associated with a homozygous variant in a newly identified gene.


Assuntos
Transtornos Cromossômicos/genética , Transtornos Cognitivos/genética , Transtornos Heredodegenerativos do Sistema Nervoso/genética , Transtornos da Visão/genética , Adolescente , Substituição de Aminoácidos , Pré-Escolar , Transtornos Cromossômicos/diagnóstico por imagem , Mapeamento Cromossômico , Transtornos Cognitivos/diagnóstico por imagem , Feminino , Seguimentos , Genótipo , Transtornos Heredodegenerativos do Sistema Nervoso/diagnóstico por imagem , Sequenciamento de Nucleotídeos em Larga Escala , Homozigoto , Humanos , Deficiência Intelectual/genética , Masculino , Linhagem , Mutação Puntual , Radiografia , Arábia Saudita , Análise de Sequência de DNA , Irmãos
12.
J Cardiovasc Pharmacol ; 61(6): 536-44, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23429587

RESUMO

: Development of cardiac hypertrophy after thyroxin (T4) treatment is well recognized. Recently, we observed that T4-induced cardiac hypertrophy is associated with increased cardiac Rac1 expression and activity. Whether this Rac1 increase has a role in inducing this cardiac phenotype is, however, still unknown. Here, we showed that T4 treatment (500 µg/kg/d) for 2 weeks resulted in increased myocardial Rac1 activity with subsequent hypertension, cardiac hypertrophy, and left ventricular systolic dysfunction in vivo. Isolated right ventricular papillary muscles of T4-treated mice maintained their peak isometric active developed tension but exhibited significant decreases in their corresponding time to peak and in relaxation times. Positive inotropic responses to increasing pacing rate and ß-adrenergic stimulation were also depressed in these muscles. Pravastatin (10 mg/kg/d), a Rac1 inhibitor, significantly decreased myocardial Rac1 activity, hypertension, and cardiomyocyte size in T4-treated mice but could not attenuate gross heart weight or functional cardiac changes in these mice. Our data showed that T4 could activate different signaling pathways with distinct cardiovascular outcomes. We also provide the first mechanistic evidence for the partial involvement of Rac1 activation in T4-induced cardiomyocyte hypertrophy and reveal a putative role for Rac1 in the development of T4-induced hypertension.


Assuntos
Cardiomegalia/metabolismo , Coração/fisiopatologia , Contração Miocárdica/efeitos dos fármacos , Neuropeptídeos/metabolismo , Músculos Papilares/fisiopatologia , Tiroxina/toxicidade , Proteínas rac de Ligação ao GTP/metabolismo , Animais , Cardiomegalia/induzido quimicamente , Cardiomegalia/fisiopatologia , Ecocardiografia , Eletrocardiografia , Coração/efeitos dos fármacos , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/fisiopatologia , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Masculino , Camundongos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Neuropeptídeos/antagonistas & inibidores , Pravastatina/farmacologia , Proteínas rac de Ligação ao GTP/antagonistas & inibidores , Proteínas rac1 de Ligação ao GTP
13.
Nanoscale Adv ; 5(20): 5499-5512, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37822908

RESUMO

The development of metal-free supercapacitor electrodes with a high energy density is a crucial requirement in the global shift towards sustainable energy sources and industrial pursuit of an optimal supercapacitor. Indeed, from an industrial perspective, time assumes a paramount role in the manufacturing process. A majority of synthesis methods employed for the fabrication of carbon xerogel-based supercapacitor electrodes are characterized by prolonged durations, and result in relatively poor energy and power density. These limitations hinder their practical applications and impede their widespread manufacturing capabilities. In this study, carbon xerogel-based supercapacitor electrodes were made in the shortest time ever reported by making the condition highly acidic with hydrochloric acid (HCl). Furthermore, the investigation of the effect of HCl concentrations (0.1 M, 0.05 M, and 0.01 M) on the morphology and electrochemical behavior of the prepared samples is reported herein. Interestingly, the highest concentration of HCl developed the highest BET surface area, 1032 m2 g-1, which enforced the capacitive behavior to deliver a specific capacitance of 402 F g-1 at 1 A g-1 and a capacitance retention of 80.8% at a current density of 2 A g-1 in an electrolyte containing 0.5 M H2SO4 + 0.5 M Na2SO4. Moreover, an impressive energy density of 45 W h kg-1 at a power density of 18.2 kW kg-1 was achieved. Interestingly, as the HCl concentration increased, the equivalent series resistance decreased to 3.9 W with carbon xerogel 0.1 M HCl (CX0.1). The superior performance of CX0.1 may be attributed to its enlarged BET surface area, pore volume, pore diameter, and smaller particle size. This work provides a facile approach for the large-scale production of metal-free carbon supercapacitor electrodes with improved performance and stability and opens novel horizons to explore the impacts of many types of catalysts during the carbon xerogel preparation.

14.
J Cardiovasc Pharmacol ; 60(6): 544-52, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22967989

RESUMO

Hypertension is a major health problem and a main risk factor for cardiovascular diseases. We have shown that overexpression of profilin-1 in blood vessels of transgenic mice generates mechanical tone and led to vascular remodeling/hypertension. However, little is known whether cardiac contractile performance in these mice is compromised. We investigated the in vivo contractile function and in vitro contractile performance using isolated papillary muscles from both right ventricle and left ventricle of profilin-1 mice at older age. Our results showed mild left ventricular hypertrophy and moderate systolic dysfunction in profilin-1 mice as evident by increased heart/body weight ratio and echocardiography analysis. Under near physiological conditions, right ventricle papillary muscles of profilin-1 mice maintained their peak isometric active developed tension, and the rate of force development over the entire frequency range of 4-14 Hz. Positive inotropic responses to increasing Ca and ß-adrenergic stimulation were also maintained. Conversely, left ventricular papillary muscles of profilin-1 mice exhibited depressed peak isometric, peak isometric active developed tension and rate of force development, and depressed positive inotropic responses to increasing Ca and ß-adrenergic stimulation. We here provide functional evidence that a significant contractile dysfunction in profilin-1 mice exists. Targeting vascular profilin-1 signaling could represent a promising therapeutic approach in hypertensive patients.


Assuntos
Hipertensão/etiologia , Hipertrofia Ventricular Esquerda/etiologia , Contração Miocárdica , Músculos Papilares/metabolismo , Profilinas/metabolismo , Disfunção Ventricular Esquerda/etiologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Cálcio/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Hipertensão/genética , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Hipertrofia Ventricular Esquerda/genética , Hipertrofia Ventricular Esquerda/metabolismo , Hipertrofia Ventricular Esquerda/fisiopatologia , Camundongos , Camundongos Transgênicos , Contração Miocárdica/efeitos dos fármacos , Músculos Papilares/efeitos dos fármacos , Músculos Papilares/fisiopatologia , Profilinas/genética , Sístole , Disfunção Ventricular Esquerda/genética , Disfunção Ventricular Esquerda/metabolismo , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Direita
15.
ACS Omega ; 7(38): 34127-34135, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36188318

RESUMO

Glassy carbon electrode (GCE) was electrochemically activated using a repetitive cyclic voltammetric technique to develop an activated glassy carbon electrode (AGCE). The developed AGCE was optimized and utilized for the electrochemical assay of 4-nitrophenol (4-NP) and dopamine (DA). Cyclic voltammetry (CV) was employed to investigate the electrochemical behavior of the AGCE. Compared to the bare GCE, the developed AGCE exhibits a significant increase in redox peak currents of 4-NP and DA, which indicates that the AGCE significantly improves the electrocatalytic reduction of 4-NP and oxidation of DA. The electrochemical signature of the activation process could be directly associated with the formation of oxygen-containing surface functional groups (OxSFGs), which are the main reason for the improved electron transfer ability and the enhancement of the electrocatalytic activity of the AGCE. The effects of various parameters on the voltammetric responses of the AGCE toward 4-NP and DA were studied and optimized, including the pH, scan rate, and accumulation time. Differential pulse voltammetry (DPV) was also utilized to investigate the analytical performance of the AGCE sensing platform. The optimized AGCE exhibited linear responses over the concentration ranges of 0.04-65 µM and 65-370 µM toward 4-NP with a lower limit of detection (LOD) of 0.02 µM (S/N = 3). Additionally, the AGCE exhibited a linear responses over the concentration ranges of 0.02-1.0 and 1.0-100 µM toward DA with a lower limit of detection (LOD) of 0.01 µM (S/N = 3). Moreover, the developed AGCE-based 4-NP and DA sensors are distinguished by their high sensitivity, excellent selectivity, and repeatability. The developed sensors were successfully applied for the determination of 4-NP and DA in real samples with satisfactory recovery results.

16.
Am J Physiol Heart Circ Physiol ; 301(3): H868-80, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21622832

RESUMO

Rac1-GTPase activation plays a key role in the development and progression of cardiac remodeling. Therefore, we engineered a transgenic mouse model by overexpressing cDNA of a constitutively active form of Zea maize Rac gene (ZmRacD) specifically in the hearts of FVB/N mice. Echocardiography and MRI analyses showed cardiac hypertrophy in old transgenic mice, as evidenced by increased left ventricular (LV) mass and LV mass-to-body weight ratio, which are associated with relative ventricular chamber dilation and systolic dysfunction. LV hypertrophy in the hearts of old transgenic mice was further confirmed by an increased heart weight-to-body weight ratio and histopathology analysis. The cardiac remodeling in old transgenic mice was coupled with increased myocardial Rac-GTPase activity (372%) and ROS production (462%). There were also increases in α(1)-integrin (224%) and ß(1)-integrin (240%) expression. This led to the activation of hypertrophic signaling pathways, e.g., ERK1/2 (295%) and JNK (223%). Pravastatin treatment led to inhibition of Rac-GTPase activity and integrin signaling. Interestingly, activation of ZmRacD expression with thyroxin led to cardiac dilation and systolic dysfunction in adult transgenic mice within 2 wk. In conclusion, this is the first study to show the conservation of Rho/Rac proteins between plant and animal kingdoms in vivo. Additionally, ZmRacD is a novel transgenic model that gradually develops a cardiac phenotype with aging. Furthermore, the shift from cardiac hypertrophy to dilated hearts via thyroxin treatment will provide us with an excellent system to study the temporal changes in cardiac signaling from adaptive to maladaptive hypertrophy and heart failure.


Assuntos
Hipertrofia Ventricular Esquerda/enzimologia , Miocárdio/enzimologia , Proteínas de Plantas/metabolismo , Disfunção Ventricular Esquerda/enzimologia , Função Ventricular Esquerda , Remodelação Ventricular , Proteínas rac1 de Ligação ao GTP/metabolismo , Envelhecimento , Sequência de Aminoácidos , Análise de Variância , Animais , Ecocardiografia , Genótipo , Hipertrofia Ventricular Esquerda/diagnóstico , Hipertrofia Ventricular Esquerda/genética , Hipertrofia Ventricular Esquerda/fisiopatologia , Integrina alfa1/metabolismo , Integrina beta1/metabolismo , Sistema de Sinalização das MAP Quinases , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Mutação , Miocárdio/patologia , Cadeias Pesadas de Miosina/genética , Fenótipo , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Pravastatina/farmacologia , Regiões Promotoras Genéticas , Superóxidos/metabolismo , Tiroxina/farmacologia , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/genética , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda/efeitos dos fármacos , Função Ventricular Esquerda/genética , Remodelação Ventricular/efeitos dos fármacos , Remodelação Ventricular/genética , Proteínas rac1 de Ligação ao GTP/antagonistas & inibidores , Proteínas rac1 de Ligação ao GTP/genética
17.
Lipids Health Dis ; 10: 6, 2011 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-21235803

RESUMO

BACKGROUND: Obesity became major health problem in the world, the objective of this work was to examine the effect of high sucrose and high fat diet to induce obesity on antioxidant defense system, biochemical changes in blood and tissue of control, non treated and treated groups by administration of Garcinia cambogia, and explore the mechanisms that link obesity with altered renal function. METHODS: Rats were fed a standard control diet for 12 week (wk) or a diet containing 65% high sucrose (HSD) or 35% fat (HFD) for 8 wk and then HFD group divided into two groups for the following 4 wks. One group was given Garcinia+HFD, the second only high fat, Also the HSD divided into two groups, 1st HSD+Garcinia and 2nd HSD. Blood and renal, mesenteric, Perirenal and epididymal adipose tissues were collected for biochemical assays. RESULTS: HFD and HSD groups of rats showed a significant increase in feed intake, Body weight (BW) and body mass index (BMI). Also there were significant increases in weights of mesenteric, Perirenal and epididymal adipose tissues in HFD and HSD groups.HFD and HSD affect the kidney by increasing serum urea and creatinine levels and decreased level of nitric oxide (NO) and increased blood glucose, low density lipoproteins (LDL), triacylglycerol (TG), total cholesterol (TC) and malondialdehyde (MDA). Glucose 6-phosphate dehydrogenase (G6PD) activities were significantly decreased in HFD while there were significant increases in HSD and HSD+G groups p ≤ 0.05 compared with control. Moreover, renal catalase activities and MDA levels were significantly increased while NO level was lowered. These changes improved by Garcinia that decreased the oxidative stress biomarkers and increased NO level.There were significant positive correlations among BMI, kidney functions (Creatinine and urea), TG and Oxidative markers (renal MDA and catalase). CONCLUSIONS: Rats fed a diet with HFD or HSD showed, hypertriglyceridemia, increased LDL production, increased oxidative stress and renal alteration. Moreover, suggesting association between lipid peroxidation, obesity and nephropathy, while Garcinia ameliorated the damaging effects of the HFD or HSD and decreased feed intake, MDA level and decreased oxidative stress in renal tissues.


Assuntos
Gorduras na Dieta/administração & dosagem , Sacarose Alimentar/administração & dosagem , Garcinia cambogia , Rim/efeitos dos fármacos , Obesidade/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Substâncias Protetoras/administração & dosagem , Animais , Distribuição da Gordura Corporal , Pesos e Medidas Corporais , Catalase/metabolismo , Ingestão de Alimentos/efeitos dos fármacos , Glucosefosfato Desidrogenase/sangue , Humanos , Rim/metabolismo , Lipídeos/sangue , Masculino , Malondialdeído/sangue , Óxido Nítrico/metabolismo , Obesidade/metabolismo , Fitoterapia , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Ratos , Ratos Wistar
18.
Lipids Health Dis ; 10: 74, 2011 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-21569551

RESUMO

AIMS: This study aimed to examine the effect of high fat diet (HFD) to modulate brain dysfunction, and understand the linkages between obesity, metabolic disturbances and the brain oxidative stress (BOS) dysfunction and modulation with hydroxyl citric acid of G. Cambogia. METHODS: Rats were divided into 3 groups; 1st control, maintained on standard normal rat chow diet, 2nd HFD, maintained on high fat diet along 12 week and 3rd HFD+G, administered G. Cambogia for 4 weeks and each group include 8 rats. Blood, brain and abdominal fat were collected for biochemical measurements. RESULTS: HFD group showed significant increase in energy intake, final BW and BW gain. Also significant increase in weight of abdominal fat in HFD group. HFD induce metabolic disturbance through increasing the lipid profile (LDL, TG, TC), γGT and α-amylase activity, uric acid level and hyperglycemia, while decreasing creatine kinase (CK) activity.These changes associated with lowering in brain nitric oxide (NO) level and rising in serum butyrylcholinesterase (BChE), brain catalase activity and MDA levels as oxidative stress markers. These alterations improved by G. Cambogia that decrease BOS and increased NO level. CONCLUSIONS: Rats fed HFD showed, metabolic disturbances produce hyperglycemia, hypertriglyceridemia, hypercholesterolemia and increased LDL associated with increased BOS. Involvement of BuChE, NO and oxidative stress associated with metabolic disturbances in the pathophysiological progression in brain, suggesting association between obesity, metabolic disorders and brain alteration while, using G. Cambogia, ameliorate the damaging effects of the HFD via lowering feed intake and BOS.


Assuntos
Encéfalo/metabolismo , Encéfalo/fisiopatologia , Citratos/farmacologia , Dieta , Gorduras na Dieta/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Gordura Abdominal/efeitos dos fármacos , Gordura Abdominal/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Catalase/metabolismo , Colesterol/sangue , Gorduras na Dieta/administração & dosagem , Ingestão de Energia/efeitos dos fármacos , Garcinia cambogia/química , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Masculino , Malondialdeído/metabolismo , Óxido Nítrico/metabolismo , Ratos , Ratos Wistar
19.
Med Teach ; 32(3): 219-24, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20218836

RESUMO

BACKGROUND: The Gulf Cooperation Council (GCC) countries have witnessed over the last 40 years a rapid and major social, cultural, and economic transformation. The development of medical education in the region is relatively new, dating from the late 1960s. An important goal among the medical colleges in the region is to graduate national physicians who can populate the healthcare service of each country. AIM: The aim of this study is to provide understanding of undergraduate medical education in each of the six GCC countries and the challenges that each face. METHODS: This is a descriptive cross-sectional study. Fourteen senior medical faculty were requested to submit information about undergraduate medical education in their own countries, focusing on its historical background, student selection, curriculum, faculty, and challenges. RESULTS: The information provided was about 27 medical colleges: 16 from the Kingdom of Saudi Arabia (KSA), five from the United Arab Emirates (UAE), two from the Kingdom of Bahrain, two from Sultanate of Oman, one from Kuwait, and one from the State of Qatar. It was found that older colleges are reviewing their curriculum while new colleges are developing their programs following current trends in medical education, particularly problem-based learning and integrated curricula. The programs as described 'on paper' look good but what needs to be evaluated is the curriculum 'in action'. Faculty development in medical education is taking place in most of the region's medical colleges. CONCLUSION: The challenges reported were mainly related to shortages of faculty, availability of clinical training facilities and the need to more integration with the National Health Care services. Attention to quality, standards, and accreditation is considered essential by all colleges.


Assuntos
Educação de Graduação em Medicina , Cooperação Internacional , Estudos Transversais , Currículo , Docentes de Medicina , Humanos , Oceano Índico , Omã , Arábia Saudita , Emirados Árabes Unidos
20.
Med Teach ; 32(4): 290-5, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20353324

RESUMO

BACKGROUND: The Gulf Cooperation Council (GCC) countries have witnessed over the last 40 years a rapid and major social, cultural, and economic transformation. The development of medical education in the region is relatively new, dating from the late 1960s. An important goal among the medical colleges in the region is to graduate national physicians who can populate the healthcare service of each country. AIM: The aim of this study is to provide understanding of undergraduate medical education in each of the six GCC countries and the challenges that each face. METHODS: This is a descriptive cross-sectional study. Fourteen senior medical faculty were requested to submit information about undergraduate medical education in their own countries, focusing on its historical background, student selection, curriculum, faculty, and challenges. RESULTS: The information provided was about 27 medical colleges: 16 from the Kingdom of Saudi Arabia (KSA), five from the United Arab Emirates, two from the Kingdom of Bahrain, two from Sultanate of Oman, one from Kuwait and one from the State of Qatar. It was found that older colleges are reviewing their curriculum while new colleges are developing their programs following current trends in medical education particularly problem-based learning and integrated curricula. The programs as described 'on paper' look good but what needs to be evaluated is the curriculum 'in action'. Faculty development in medical education is taking place in most of the region's medical colleges. CONCLUSION: The challenges reported were mainly related to shortages of faculty, availability of clinical training facilities, and the need to more integration with the National Health Care services. Attention to quality, standards, and accreditation is considered essential by all colleges.


Assuntos
Educação de Graduação em Medicina/organização & administração , Cooperação Internacional , Acreditação , Estudos Transversais , Currículo , Avaliação Educacional , Docentes de Medicina , Oriente Médio , Avaliação de Programas e Projetos de Saúde , Critérios de Admissão Escolar
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