615 research outputs found

    CYP2D6 genetic polymorphisms are associated with susceptibility to pituitary tumors

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    Several polymorphisms of drug-metabolizing enzymes have been implicated in the susceptibility to tumor development. The role of the CYP2D6, GSTM1 and GSTT1 genes has been extensively studied, with alleles conferring different metabolic efficiencies and tumor risk. We studied the relationship between the main polymorphisms of these genes and the susceptibility to develop pituitary tumors, by performing a case-control study comprising 235 patients and 256 controls which were genotyped by means of PCR-RFLP based assays. Frequencies of the CYP2D6*1 and of the poor metabolizer allele CYP2D6*4, were determined along with the frequencies of the GSTM1 and GSTT1 null genotypes. CYP2D6 genotype frequencies were similar in patients and controls (p=0.087). CYP2D6*1 and CYP2D6*4 allele frequencies were 83.8%, 16.2% in cases and 78.3%, 21.7% in controls, showing a significant difference between the two groups (p=0.012). There were no significant differences between the frequencies of the GSTM1 and GSTT1 null genotypes in both groups. No association was found between histological type and any of the studied polymorphisms. Our data suggest an association of the CYP2D6*1 allele and the susceptibility to pituitary adenomas, which could be due to an increased metabolism of unidentified procarcinogens or to linkage disequilibrium with another gene involved in pituitary tumorigenesis

    Overview of resistant hypertension: A glimpse of the cardiologist's current standpoint

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    Hypertension is a major risk factor for cardiovascular disease, resulting in increased incidence of cerebrovascular events, ischaemic heart disease, heart failure, and renal impairment. Thus, it is one of the most important preventable causes of premature morbidity and mortality. Despite current knowledge on the management of hypertension and the availability of several effective antihypertensive medications, uncontrolled hypertension remains a common and challenging clinical problem. Resistant hypertension is a complex condition with multiple contributing factors and overlapping comorbidities. Although there is limited hard evidence regarding resistant hypertension, our understanding of this condition has improved recently. This article will present an overview of resistant hypertension and highlight recent publications about this topic

    ORGANOPHILIC BENTONITES BASED ON ARGENTINEAN AND BRAZILIAN BENTONITES. PART 2: POTENTIAL EVALUATION TO OBTAIN NANOCOMPOSITES

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)This work describes the preparation of composites of polypropylene and organophilic bentonites based on Brazilian and Argentinean bentonites. During the processing of the samples in a twin screw microextruder, torque and pressures of the extruder were accompanied and the viscosity values were calculated. No significant changes in the torque, pressure and viscosity were found for composites prepared with different bentonites. The samples were characterized by XRD and TEM to evaluate the structure and dispersion of the organophilic bentonites. Composites with exfoliated, partially exfoliated and intercalated structures were obtained and correlations between the intrinsic properties of the sodium clays and organophilic bentonites and their influence on the composites were studied. The cation exchange capacity of the sodium bentonites and the swelling capacity of the organophilic bentonites were the most important properties to obtain exfoliated structures in composites. All bentonites showed the potential to obtain polymer nanocomposites, but the ones from Argentina displayed the best results.294751762Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    The Effect of Tear Supplementation on Ocular Surface Sensations during the Interblink Interval in Patients with Dry Eye.

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    PURPOSE: To investigate the characteristics of ocular surface sensations and corneal sensitivity during the interblink interval before and after tear supplementation in dry eye patients. METHODS: Twenty subjects (41.88+/-14.37 years) with dry eye symptoms were included in the dry eye group. Fourteen subjects (39.13+/-11.27 years) without any clinical signs and/or symptoms of dry eye were included in the control group. Tear film dynamics was assessed by non-invasive tear film breakup time (NI-BUT) in parallel with continuous recordings of ocular sensations during forced blinking. Corneal sensitivity to selective stimulation of corneal mechano-, cold and chemical receptors was assessed using a gas esthesiometer. All the measurements were made before and 5 min after saline and hydroxypropyl-guar (HP-guar) drops. RESULTS: In dry eye patients the intensity of irritation increased rapidly after the last blink during forced blinking, while in controls there was no alteration in the intensity during the first 10 sec followed by an exponential increase. Irritation scores were significantly higher in dry eye patients throughout the entire interblink interval compared to controls (p0.05). CONCLUSION: Ocular surface irritation responses due to tear film drying are considerably increased in dry eye patients compared to normal subjects. Although tear supplementation improves the protective tear film layer, and thus reduce unpleasant sensory responses, the rapid rise in discomfort is still maintained and might be responsible for the remaining complaints of dry eye patients despite the treatment

    Corneal Sensitivity and Dry Eye Symptoms in Patients with Keratoconus.

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    PURPOSE: To investigate corneal sensitivity to selective mechanical, chemical, and thermal stimulation and to evaluate their relation to dry eye symptoms in patients with keratoconus. METHODS: Corneal sensitivity to mechanical, chemical, and thermal thresholds were determined using a gas esthesiometer in 19 patients with keratoconus (KC group) and in 20 age-matched healthy subjects (control group). Tear film dynamics was assessed by Schirmer I test and by the non-invasive tear film breakup time (NI-BUT). All eyes were examined with a rotating Scheimpflug camera to assess keratoconus severity. RESULTS: KC patients had significatly decreased tear secretion and significantly higher ocular surface disease index (OSDI) scores compared to controls (5.3+/-2.2 vs. 13.2+/-2.0 mm and 26.8+/-15.8 vs. 8.1+/-2.3; p0.05). The mean threshold for selective mechanical (KC: 139.2+/-25.8 vs. control: 109.1+/-24.0 ml/min), chemical (KC: 39.4+/-3.9 vs. control: 35.2+/-1.9%CO2), heat (KC: 0.91+/-0.32 vs. control: 0.54+/-0.26 Delta degrees C) and cold (KC: 1.28+/-0.27 vs. control: 0.98+/-0.25 Delta degrees C) stimulation in the KC patients were significantly higher than in the control subjects (p0.05), whereas in the control subjects both mechanical (r = 0.52, p = 0.02), chemical (r = 0.47, p = 0.04), heat (r = 0.26, p = 0.04) and cold threshold (r = 0.40, p = 0.03) increased with age. In the KC group, neither corneal thickness nor tear flow, NI-BUT or OSDI correlated significantly with mechanical, chemical, heat or cold thresholds (p>0.05 for all variables). CONCLUSIONS: Corneal sensitivity to different types of stimuli is decreased in patients with keratoconus independently of age and disease severity. The reduction of the sensory input from corneal nerves may contribute to the onset of unpleasant sensations in these patients and might lead to the impaired tear film dynamics

    Two-Particle-Self-Consistent Approach for the Hubbard Model

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    Even at weak to intermediate coupling, the Hubbard model poses a formidable challenge. In two dimensions in particular, standard methods such as the Random Phase Approximation are no longer valid since they predict a finite temperature antiferromagnetic phase transition prohibited by the Mermin-Wagner theorem. The Two-Particle-Self-Consistent (TPSC) approach satisfies that theorem as well as particle conservation, the Pauli principle, the local moment and local charge sum rules. The self-energy formula does not assume a Migdal theorem. There is consistency between one- and two-particle quantities. Internal accuracy checks allow one to test the limits of validity of TPSC. Here I present a pedagogical review of TPSC along with a short summary of existing results and two case studies: a) the opening of a pseudogap in two dimensions when the correlation length is larger than the thermal de Broglie wavelength, and b) the conditions for the appearance of d-wave superconductivity in the two-dimensional Hubbard model.Comment: Chapter in "Theoretical methods for Strongly Correlated Systems", Edited by A. Avella and F. Mancini, Springer Verlag, (2011) 55 pages. Misprint in Eq.(23) corrected (thanks D. Bergeron

    Qualidade dos cuidados de enfermagem e satisfação do paciente atendido em um hospital de ensino

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    OBJECTIVES: assess the quality of nursing care, the patients' satisfaction and the correlation between both. METHOD: cross-sectional study, involving 275 patients hospitalized at a teaching hospital in the Central-West of Brazil. The data were collected through the simultaneous application of three instruments. Next, they were included in an electronic database and analyzed in function of the positivity, median value and Spearman's correlation coefficients. RESULTS: among the nursing care assessed, only two were considered safe - hygiene and physical comfort; nutrition and hydration - while the remainder were classified as poor. Nevertheless, the patients were satisfied with the care received in the domains assessed: technical-professional, confidence and educational. This can be justified by the weak to moderate correlation that was observed among these variables. CONCLUSION: Despite the quality deficit, the patients' satisfaction level with the nursing care received was high. These results indicate that the institution needs to center its objectives on a continuing evaluation system of the care quality, aiming to attend to the patients' expectations.OBJETIVOS: evaluar la calidad de los cuidados de enfermería, la satisfacción del paciente y la correlación entre ambos. MÉTODO: estudio trasversal con 275 pacientes internados en un hospital de enseñanza de la región Centro-Oeste de Brasil. Los datos fueron recolectados mediante la aplicación simultánea de tres instrumentos. A seguir, fueron digitalizados en un banco de datos electrónico y analizados en función de la positividad, valor de mediana y coeficientes de correlación de Spearman. RESULTADOS: entre los cuidados de enfermería evaluados, solamente dos fueron considerados seguros - higiene y conforto físico; nutrición e hidratación - y los demás clasificados como pobres. Sin embargo, los pacientes se mostraron satisfechos con los cuidados recibidos en los dominios evaluados: técnico-profesional, confianza y educacional. Eso puede ser justificado por la correlación débil a moderada observada entre esas variables. CONCLUSIÓN: A pesar del déficit de cualidad, fue encontrado alto nivel de satisfacción de los pacientes con los cuidados de enfermería recibidos. Tales resultados indican la necesidad de que la institución centre sus objetivos en un sistema de evaluación permanente de la cualidad del cuidado, visando atender a las expectativas de los pacientes.OBJETIVOS: avaliar a qualidade dos cuidados de enfermagem, a satisfação do paciente e a correlação entre ambos. MÉTODO: estudo transversal, realizado com 275 pacientes internados em um hospital de ensino da Região Centro-Oeste do Brasil. Os dados foram obtidos por meio da aplicação simultânea de três instrumentos. A seguir, foram digitados em banco de dados eletrônico e analisados em função da positividade, valor de mediana e coeficientes de correlação de Spearman. RESULTADOS: dentre os cuidados de enfermagem avaliados, apenas dois foram considerados seguros - higiene e conforto físico; nutrição e hidratação - e os demais foram classificados como pobres. Todavia, os pacientes mostraram-se satisfeitos com os cuidados recebidos nos domínios avaliados: técnico-profissional, confiança e educacional. Isso pode ser justificado pela correlação fraca a moderada observada entre essas variáveis. CONCLUSÃO: apesar do déficit de qualidade, houve alto nível de satisfação dos pacientes com os cuidados de enfermagem recebidos. Tais resultados apontam a necessidade de a instituição centrar seus objetivos num sistema de avaliação permanente da qualidade do cuidado, visando o atendimento das expectativas dos pacientes
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