234 resultados para Third-order correlation


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Background The development of products and services for health care systems is one of the most important phenomena to have occurred in the field of health care over the last 50 years. It generates significant commercial, medical and social results. Although much has been done to understand how health technologies are adopted and regulated in developed countries, little attention has been paid to the situation in low- and middle-income countries (LMICs). Here we examine the institutional environment in which decisions are made regarding the adoption of expensive medical devices into the Brazilian health care system. Methods We used a case study strategy to address our research question. The empirical work relied on in-depth interviews (N = 16) with representatives of a wide range of actors and stakeholders that participate in the process of diffusion of CT (computerized tomography) scanners in Brazil, including manufacturers, health care organizations, medical specialty societies, health insurance companies, regulatory agencies and the Ministry of Health. Results The adoption of CT scanners is not determined by health policy makers or third-party payers of public and private sectors. Instead, decisions are primarily made by administrators of individual hospitals and clinics, strongly influenced by both physicians and sales representatives of the medical industry who act as change agents. Because this process is not properly regulated by public authorities, health care organizations are free to decide whether, when and how they will adopt a particular technology. Conclusions Our study identifies problems in how health care systems in LMICs adopt new, expensive medical technologies, and suggests that a set of innovative approaches and policy instruments are needed in order to balance the institutional and professional desire to practise a modern and expensive medicine in a context of health inequalities and basic health needs.

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There is a positive correlation between the intensity of use of a given antibiotic and the prevalence of resistant strains. The more you treat, more patients infected with resistant strains appears and, as a consequence, the higher the mortality due to the infection and the longer the hospitalization time. In contrast, the less you treat, the higher the mortality rates and the longer the hospitalization time of patients infected with sensitive strains that could be successfully treated. The hypothesis proposed in this paper is an attempt to solve such a conflict: there must be an optimum treatment intensity that minimizes both the additional mortality and hospitalization time due to the infection by both sensitive and resistant bacteria strains. In order to test this hypothesis we applied a simple mathematical model that allowed us to estimate the optimum proportion of patients to be treated in order to minimize the total number of deaths and hospitalization time due to the infection in a hospital setting. (C) 2007 Elsevier Inc. All rights reserved.

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We studied the anisotropic aggregation of spherical latex particles dispersed in a lyotropic liquid crystal presenting three nematic phases; calamitic, biaxial, and discotic. We observed that in the nematic calamitic phase aggregates of latex particles are formed, which become larger and anisotropic in the vicinity of the transition to the discotic phase, due to a coalescence process. Such aggregates are weakly anisotropic and up to 50 mu m long and tend to align parallel to the director field. At the transition to the discotic phase, the aggregates dissociated and re-formed when the system was brought back to the calamitic phase. This shows that the aggregation is due to attractive and repulsive forces generated by the particular structure of the nematic phase. The surface-induced positional order was investigated by surface force apparatus experiments with the lyotropic system confined between mica surfaces, revealing the existence of a presmectic wetting layer around the surfaces and oscillating forces of increasing amplitude as the confinement thickness was decreased. We discuss the possible mechanisms responsible for the reversible aggregation of latex particles, and we propose that capillary condensation of the N(C) phase, induced by the confinement between the particles, could reduce or remove the gradient of order parameter, driving the transition of aggregates from solidlike to liquidlike and gaslike.

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Particulate matter, especially PM2.5, is associated with increased morbidity and mortality from respiratory diseases. Studies that focus on the chemical composition of the material are frequent in the literature, but those that characterize the biological fraction are rare. The objectives of this study were to characterize samples collected in Sao Paulo, Brazil on the quantity of fungi and endotoxins associated with PM2.5, correlating with the mass of particulate matter, chemical composition and meteorological parameters. We did that by Principal Component Analysis (PCA) and multiple linear regressions. The results have shown that fungi and endotoxins represent significant portion of PM2.5, reaching average concentrations of 772.23 spores mu g(-1) of PM2.5 (SD: 400.37) and 5.52 EU mg(-1) of PM2.5 (SD: 4.51 EU mg(-1)), respectively. Hyaline basidiospores, Cladosporium and total spore counts were correlated to factor Ba/Ca/Fe/Zn/K/Si of PM2.5 (p < 0.05). Genera Pen/Asp were correlated to the total mass of PM2.5 (p < 0.05) and colorless ascospores were correlated to humidity (p < 0.05). Endotoxin was positively correlated with the atmospheric temperature (p < 0.05). This study has shown that bioaerosol is present in considerable amounts in PM2.5 in the atmosphere of Sao Paulo, Brazil. Some fungi were correlated with soil particle resuspension and mass of particulate matter. Therefore, the relative contribution of bioaerosol in PM2.5 should be considered in future studies aimed at evaluating the clinical impact of exposure to air pollution. (C) 2010 Elsevier Ltd. All rights reserved.

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Brain-derived neurotrophic factor (BDNF) is the most widely distributed neurotrophin in the CNS, where it plays several pivotal roles in synaptic plasticity and neuronal survival. As a consequence, BDNF has become a key target in the physiopathology of several neurological and psychiatric diseases. Recent studies have consistently reported altered levels of BDNF in the circulation (i.e., serum or plasma) of patients with major depression, bipolar disorder, Alzheimer`s disease, Huntington`s disease and Parkinson`s disease. Correlations between serum BDNF levels and affective, cognitive and motor symptoms have also been described. BDNF appears to be an unspecific biomarker of neuropsychiatric disorders characterized by neurodegenerative changes.

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Deeply infiltrating endometriosis (DIE) is a common gynecologic disease that is characterized by a difficult and delayed diagnosis. Radiologic mapping of the DIE lesion sites is crucial for case management, patient counseling, and surgical planning. Transvaginal ultrasonography (US) is the initial imaging modality for investigating DIE and has been the focus of several recent studies. DIE typically manifests at imaging as hypoechogenic nodules throughout the affected sites and thickening of the intestinal wall, with some lesions showing a mixed pattern due to cystic areas. Transvaginal US performed after bowel preparation improves the ability to diagnose intestinal lesions and provides invaluable details, including which layers of the intestine are affected and the distance between the lesion and the anal border. It is vital that radiologists be familiar with the technical aspects of this modality and with the US manifestations of DIE lesions. Transvaginal US performed after bowel preparation should be the first-line imaging modality for the evaluation of women with suspected endometriosis. (C) RSNA, 2010 . radiographics.rsna.org

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The 16q21 -> qter duplication is a chromosomal abnormality rarely found in liveborn infants, with only four published cases. We report here on the 7-year follow-up of a female patient with trisomy 16q21 -> qter due to a maternal balanced translocation t(4;16)(q35.2;q21). The patient shows severe mental retardation, congenital heart malformations, nephropathy, and other congenital anomalies. The derivative chromosome was characterized by GTG banding, fluorescent in situ hybridization (FISH) with different BAG probes and the array technique, in order to map the breakpoints. The patient has a 16q21 -> qter duplication, with a 4q35 -> qter monosomy, which we assume does not contribute to the abnormal phenotype. This is the first reported case of postnatal survival to the age of 7 years, an unusually long time in this chromosomal syndrome. (C) 2010 Wiley-Liss, Inc.

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Endoscopic third ventriculostomy (ETV) has been established as an effective method in the treatment of tumoral obstructive hydrocephalus. Delayed closure of the ETV stoma has been attributed to scarring involving the third ventricular floor. Secondary obstruction of the stoma due to intraventricular tumor seeding is an extremely rare condition, with only one case described to date. The authors report on a unique case of late closure of the ETV stoma caused by metastatic seeding of a recurrent medulloblastoma 9 years after the initial treatment. The patient was submitted to a second endoscopic procedure in which a reddish mass located just at the third ventricular floor was resected, leading to reopening of the previous ETV stoma. To the best of the authors` knowledge, this case is the first report of an ETV obstruction due to metastatic CSF seeding of a medulloblastoma. In such cases of late failure of the ETV stoma because of tumor obstruction, a second ETV can be safely performed and lead to adequate function of the stoma, even if limited by the aggressive nature of the disease. (DOI: 10.3171/2010.1.PEDS09320)

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Objective: to describe women`s feelings about mode of birth. Design: exploratory descriptive design. Semi-structured interviews were conducted using a questionnaire that had been developed previously (categorical data and open-and closed-ended questions). Qualitative analysis of the results was performed through a context analysis technique. Setting: the largest public university hospital in Brazil. Participants: 48 women in their third trimester of pregnancy. Findings: most women expressed a preference for vaginal birth, as they perceived that they would have a faster recovery. Women who expressed a preference for caesarean section did so because of lack of pain during the birth and the need for tubal sterilisation. The majority of women considered it important to have experience with a mode of birth in order to choose a preference. Complications associated with maternal illness were very influential in the decision-making process. Key conclusions: these results provide a useful first step towards the identification of aspects of women`s feelings about modes of birth. Most women expressed a preference for vaginal birth. Further exploration of women`s feelings regarding parturition and the decision-making process is required. (C) 2008 Elsevier Ltd. All rights reserved.

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Background: Obsessive-compulsive disorder (OCD) is characterized by repeated and persistent attempts to control thoughts and actions with rituals. These rituals are used in order to prevent feared or personally distressing outcomes. Cognitive behavioral group therapy (CBGT) has been reported to be effective for treating OCD patients. However, about one-third (30%) of patients do not benefit from CBGT. Some of these patients do not show significant improvement and continue to use rituals following CBGT, partially because they fail to complete the exposure and ritual prevention (ERP) exercises. Consequently, it is important to motivate patients to fully engage in CBGT treatment and complete the ERP exercises. Aims: A randomized behavioral trial examined 12 weeks of manual directed CBGT, with the addition of individual sessions of Motivational Interviewing (MI) and Thought Mapping (TM), and compared treatment outcome to the effectiveness of CBGT group alone. Method: Subjects were randomized (n = 93) into a CBGT group or a CBGT group with MI+TM. Results: When the two groups were compared, both groups reduced OCD symptoms. However, symptom reduction and remission were significantly higher in the MI+TM CBGT group. Positive outcomes were also maintained, with additional symptom reduction at the 3-month follow-up for the MI TM CBGT group. Conclusions: Adding two individual sessions of MI and TM before CBGT successfully reduced OCD symptoms and was more effective than using CBGT group alone.

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Background Chronic aortic valve disease (AVD) is characterized by progressive accumulation of interstitial myocardial fibrosis (MF). However, assessment of MF accumulation has only been possible through histologic analyses of endomyocardial biopsies. We sought to evaluate contrast-enhanced magnetic resonance imaging (ce-MRI) as a noninvasive method to identify the presence of increased MF in patients with severe AVD. Methods Seventy patients scheduled to undergo aortic valve replacement surgery were examined by cine and ce-MRI in a 1.5-T scanner. Cine images were used for the assessment of left ventricular (LV) volumes, mass, and function. Delayed-enhancement images were used to characterize the regions of MF. In addition, histologic analyses of myocardial samples obtained during aortic valve replacement surgery were used for direct quantification of interstitial MF. Ten additional subjects who died of noncardiac causes served as controls for the quantitative histologic analyses. Results Interstitial MF determined by histopathologic analysis was higher in patients with AVID than in controls (2.7% +/- 2.0% vs 0.6% +/- 0.2%, P =.001). When compared with histopathologic results, ce-MRI demonstrated a sensitivity of 74%, a specificity of 81%, and an accuracy of 76% to identify AVD patients with increased interstitial MF There was a significant inverse correlation between interstitial MF and LV ejection fraction (r = -0.67, P <.0001). Accordingly, patients with identifiable focal regions of MF by ce-MRI exhibited worse LV systolic function than those without MF (45% +/- 14% vs 65% +/- 14%, P <.0001). Conclusions Contrast-enhanced MRI allows for the noninvasive detection of focal regions of MF in patients with severe AVD. Moreover, patients with identifiable MF by ce-MRI exhibited worse LV functional parameters. (Am Heart J 2009; 157:361-8.)

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BACKGROUND: One of the key elements for a successful endoscopic intervention in the ventricular system is the ability to recognize the anatomic structures and use them as a reference. OBJECTIVE: To measure the choroid plexus with endoscopy in the interventricular foramen, together with the structures on the third ventricle floor, and to compare these variables. METHODS: An observational prospective study was carried out on 37 brains of cadavers for which the cause of death was assessed at the Death Check Unit of the University of Sao Paulo in April 2008. This study was done on adults of both sexes with a rigid neuroendoscope. Endoscopic images were recorded, submitted for correction of distortion, and then measured. RESULTS: The measurements of the choroid plexus in the interventricular foramen, laterolateral distance of mammillary bodies, distance from the infundibular recess to the mammillary bodies, and area of the triangle in the tuber cinereum were 1.71 +/- 0.77 mm, 2.23 +/- 0.74 mm, 3.22 +/- 0.82 mm, and 3.69 +/- 2.09 mm(2), respectively. The ventricle floor was opaque in 84% of cases. The internal distance of mammillary bodies was absent in 89%. Associations between the translucent floor of the third ventricle and laterolateral distance of mammillary bodies, internal distance of mammillary bodies, and age were identified. CONCLUSION: Before this research, there was no record of the measurements of the choroid plexus in the interventricular foramen. The remaining variables of the present study show a greater number in normal brains compared with others.

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Our purpose was to study the determinants of coronary and carotid subclinical atherosclerosis, aortic stiffness and their relation with inflammatory biomarkers in familial hypercholesterolemia (FH) subjects. Furthermore, we evaluated the agreement degree of imaging and inflammatory markers` severity used for coronary heart disease (CHD) prediction. Coronary calcium scores (CCS), carotid intima media thickness (IMT), carotid-femoral pulse wave velocity (PWV), C reactive protein (CRP) and white blood cells count (WBC) were determined in 89 FH patients (39 +/- 14 years, mean LDL-C=279 mg/dl) and in 31 normal subjects (NL). The following values were considered as imaging and biomarkers` severity: CCS > 75th% for age and sex, IMT > 900 mu m, PWV > 12 m/s, and CRP > 3 mg/l. Coronary artery calcification (CAC) prevalence and severity, IMT, PWV and WBC values were higher in FH than in NL (all parameters, p < 0.05). After multivariate analysis, the following variables were considered independent determinants of (1) IMT: systolic blood pressure, 10-year CHD risk by Framingham risk scores (FRS) and apolipoprotein B (r(2)=0.33); (2) PWV: age (r(2)=0.35); (3) CAC as a continuous variable: male gender and LDL-cholesterol year score (LYS) (r(2)=0.32); (4) presence of CAC as dichotomous variable: FRS (p=0.0027) and LYS (p=0.0228). With the exception of a moderate agreement degree between IMT and PWV severity (kappa=0.5) all other markers had only a slight agreement level (kappa < 0.1). In conclusion, clinical parameters poorly explained IMT, CAC and PWV variability in FH subjects. Furthermore, imaging markers and inflammatory biomarkers presented a poor agreement degree of their severity for CHD prediction. (C) 2007 Elsevier Ireland Ltd. All rights reserved.

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Wood-dwelling termites are characterized by an extremely high and unique developmental flexibility that allows workers, which are immatures, to explore all caste options. The endocrine signatures underlying this flexibility are only vaguely understood. We determined juvenile hormone (JH) and ecdysteroid hemolymph titers during postembryonic development and in terminal instars of the drywood termite Cryptotermes secundus using field and laboratory colonies. Postembryonic development is characterized by a drop in JH titers at the transition from larval (individuals without wing buds) to nymphal (individuals with wing buds) instars. JH titers were low in winged sexuals and reproducing primary reproductives (< 200 pg/mu l) but were by an order of magnitude higher in neotenic replacement reproductives. The unique regressive molts of termites seem to be characterized by elevated JH titers, compared with progressive or stationary molts. Ecdysteroid titers were generally low in nymphal instars and in primary reproductives (< 50 pg/mu l). It was only during the third and fourth nymphal instars and in winged sexuals where some individuals showed elevated ecdysteroid titers. These results are the most comprehensive endocrinological data set available for any lower termite, with the potential to serve as baseline for understanding the extreme developmental flexibility underlying the evolution of social life in termites.

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Objective. The purpose of this study was to evaluate the diagnostic usefulness of ulnar nerve sonography in leprosy neuropathy with electrophysiologic correlation. Methods. Twenty-one consecutive patients with leprosy (12 men and 9 women; mean age +/- SD, 47.7 +/- 17.2 years) and 20 control participants (14 men and 6 women; mean age, 46.5 +/- 16.2 years) were evaluated with sonography. Leprosy diagnosis was established on the basis of clinical, bacteriologic, and histopathologic criteria. The reference standard for ulnar neuropathy in this study was clinical symptoms in patients with proven leprosy The sonographic cross-sectional areas (CSAs) of the ulnar nerve in 3 different regions were obtained. Statistical analyses included Student t tests and receiver operating characteristic curve analysis. Results. The CSAs of the ulnar nerve were significantly larger in the leprosy group than the control group for all regions (P < .01). Sonographic abnormalities in leprosy nerves included focal thickening (90.5%), hypoechoic areas (81%), loss of the fascicular pattern (33.3%), and focal hyperechoic areas (4.7%). Receiver operating characteristic curve analysis showed that a maximum CSA cutoff value of 9.8 mm(2) was the best discriminator (sensitivity, 0.91; specificity, 0.90). Three patients with normal electrophysiologic findings had abnormal sonographic findings. Two patients had normal sonographic findings, of which 1 had abnormal electrophysiologic findings, and the other refused electrophysiologic testing. Conclusions. Sonography and electrophysiology were complementary for identifying ulnar nerve neuropathy in patients with leprosy, with clinical symptoms as the reference standard. This reinforces the role of sonography in the investigation of leprosy ulnar neuropathy.