990 resultados para Comparative genomic hybridization (CGH)


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The world's deep oceans are home to a number of teleosts with asymmetrical or tubular eyes. These immobile eyes possess large spherical lenses and subtend a large binocular visual field directed either dorsally or rostrally. Derived from a lateral non-tubular eye, the tubular eye is comprised of a thick main retina, subserving the rostrally or dorsally directed binocular visual field, and a thin accessory retina subserving, the lateral, monocular visual field. The main retina is thought to receive a focussed image, while the accessory retina is too close to the lens for a focussed image to be received. Several species also possess retinal diverticula, which are small evaginations of differentiated retina located in the rostrolateral wall of the eye and thought to increase the visual field. In order to investigate the spatial resolving power of these retinae (main, accessory and diverticulum), the distribution of cells within the ganglion cell layer was analysed from retinal wholemounts and sectioned material in ten species representing four genera. In all species, the main retina possesses a marked increase in cell density towards a specialised retinal region (area centralis), with a centro-peripheral gradient range between 7.1 and 60:1 and a peak density range of between 30 and 55 x 10(3) cells per mm(2). The accessory retinae and the transitional zone between the main and accessory retinae possess relatively low cell densities (between 1 and 10 x 10(3) cells per mm(2)) and lack an area centralis. Retinal diverticula examined in four species possess mean ganglion cell densities of between 7.2 and 109.4 x 10(3) cells per mm(2). Analyses of soma areas show that the ganglion cell layer of most species possesses cells with areas in a range of 8.0 to 15.4 mu m(2) in the main retina and between 15.1 and 17.4 mu m(2) in the accessory retina. The peak spatial resolving power of the main retina of the ten species varies from 4.1 to 9.1 cycles per degree. The positions of the retinal areae centrales relative to each species' binocular visual field are discussed in relation to what is known of feeding behaviour of these fishes in the deep-sea.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Glioblastoma multiforme ( GBM) is the most common and lethal type of brain cancer. To identify the genetic alterations in GBMs, we sequenced 20,661 protein coding genes, determined the presence of amplifications and deletions using high- density oligonucleotide arrays, and performed gene expression analyses using next- generation sequencing technologies in 22 human tumor samples. This comprehensive analysis led to the discovery of a variety of genes that were not known to be altered in GBMs. Most notably, we found recurrent mutations in the active site of isocitrate dehydrogenase 1 ( IDH1) in 12% of GBM patients. Mutations in IDH1 occurred in a large fraction of young patients and in most patients with secondary GBMs and were associated with an increase in overall survival. These studies demonstrate the value of unbiased genomic analyses in the characterization of human brain cancer and identify a potentially useful genetic alteration for the classification and targeted therapy of GBMs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Since the first experiments with fibrin glue application in microvascular anastomoses in 1977, several studies have reported its benefits on suture reduction and anastomosis decreased time. In spite of that, clinical experience has been limited to two neurosurgical and two replantation case series, all of them with good results. This study was conducted to evaluate the feasibility and the potential benefits of fibrin glue application in free flaps. Methods: We performed 24 free flaps in 24 patients, from March 2005 to June 2006. Twenty were included in this study. They were divided into two groups according to the anastomosis technique: conventional group (n = 7 patients) and fibrin glue group (n = 13 patients). In the conventional group, the anastomosis was performed with interrupted sutures, whereas in the fibrin glue group, they were performed using less sutures and fibrin glue application. Results: The application of fibrin glue cut by half the number of sutures required to complete the anastomoses. The mean arterial and venous anastomotic times in the conventional group were 27.2 and 24.0 minutes, respectively. In the fibrin glue group, they were 13.6 and 12.6 minutes, respectively. All these differences were statistically significant. There was no significant difference of ischemic time between two groups (P = 0.26). The survival rate of the flaps was similar in both groups: 84.6% (11 of 13) in the fibrin glue group and 85.7% (6 of 7) in the conventional group (P = 1.0). Conclusions: Fibrin glue application in free flaps was feasible and allowed us to complete the anastomoses with fewer sutures and less time. The survival rate of the flaps was not adversely affected by the fibrin glue. (C) 2008 Wiley-Liss, Inc. Microsurgery 29:24-28, 2009.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Several studies have already reported the utilization of fibrin glue in microvascular anastomoses to minimize the number of sutures and to decrease the operative time. Despite the good results obtained in most of these experiments, its clinical application has not launched. The aim of this study was to clarify the controversies around the safeness of fibrin glue application in microvascular anastomoses, and also to demonstrate the potential benefits of fibrin glue application in a realistic free flap model. Methods: Twenty-seven rabbits were used in this study The experimental model consisted of a free groin flap transfer to the anterior cervical region. The flap`s circulation was restored by means of an end-to-side anastomosis between the femoral and carotid arteries, and an end-to-end anastomosis between the femoral and external jugular veins. The animals were divided into two groups (n = 10) according to the anastomosis technique: Group I (conventional suture) and group 11 (fibrin glue). Results: The number of sutures required to complete the arterial and venous anastomoses was reduced in 39 and 37% in group 11, respectively. Despite this reduction, the anastomoses maintained adequate patency rates and mechanical strength. Both arterial and venous anastomoses benefited from fibrin glue application, which made them easier and faster to perform. The flaps` ischemic time and the total operative time were also significantly shortened. Conclusions: In this study, the application of fibrin glue in microvascular anastomoses was safe and reliable. The risk-benefit ratio of fibrin glue application in microvascular anastomoses is favorable for its use. (c) 2008 Wiley-Liss, Inc.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Although fatigue is a ubiquitous symptom across countries, clinical descriptions of chronic fatigue syndrome have arisen from a limited number of high-income countries. This might reflect differences in true prevalence or clinical recognition influenced by sociocultural factors. Aims To compare the prevalence, physician recognition and diagnosis of chronic fatigue syndrome in London and Sao Paulo. Method Primary care patients in London (n=2459) and Sao Paulo n=3914) were surveyed for the prevalence of chronic fatigue syndrome. Medical records were reviewed for the physician recognition and diagnosis. Results The prevalence of chronic fatigue syndrome according to Centers for Disease Control 1994 criteria was comparable in Britain and Brazil, 2.1% v. 1.6% (P=0.20). Medical records review identified 11 diagnosed cases of chronic fatigue syndrome in Britain, but none in Brazil (P<0.001). Conclusions The primary care prevalence of chronic fatigue syndrome was similar in two Culturally and economically distinct nations. However, doctors are unlikely to recognise and label chronic fatigue syndrome as a discrete disorder in Brazil. The recognition of this illness rather than the illness itself may be culturally induced.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: While in many Western affluent countries there is widespread awareness of chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME), little is known about the awareness of CFS/ME in low- and middle-income countries. We compared the awareness of CFS in Brazil and the United Kingdom. Methods: Recognition and knowledge of CFS were assessed among 120 Brazilian specialist doctors in two major university hospitals using a typical case vignette of CFS. We also surveyed 3914 and 2435 consecutive attenders in Brazilian and British primary care clinics, respectively, concerning their awareness of CFS. Results: When given a typical case vignette of CFS, only 30.8% [95% confidence interval (CI), 22.7-39.9%] of Brazilian specialist doctors mentioned chronic fatigue or CFS as a possible diagnosis, a proportion substantially lower than that observed in Western affluent countries. Similarly, only 16.2% (95% CI, 15.1-17.4%) of Brazilian primary care attenders were aware of CFS, in contrast to 55.1% (95% CI, 53.1-57.1%) of their British counterparts (P <.001). This difference remained highly significant after controlling for patients` sociodemographic and socioeconomic characteristics (P <.001). Conclusions: The awareness of CFS was substantially lower in Brazil than the United Kingdom. The observed difference may influence patients` help-seeking behavior and both doctors` and patients` beliefs and attitudes in relation to fatigue-related syndromes. Attempts to promote the awareness of CFS should be considered in Brazil, but careful plans are required to ensure the delivery of sound evidence-based information. (c) 2008 Elsevier Inc. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Atypical enteropathogenic Escherichia coli (aEPEC) has been associated with infantile diarrhea in many countries. The clonal structure of aEPEC is the object of active investigation but few works have dealt with its genetic relationship with other diarrheagenic E. coli (DEC). This study aimed to evaluate the genetic relationship of aEPEC with other DEC pathotypes. The phylogenetic relationships of DEC strains were evaluated by multilocus sequence typing. Genetic diversity was assessed by pulsed-field gel electrophoresis (PFGE). The phylogram showed that aEPEC strains were distributed in four major phylogenetic groups (A, B1, B2 and D). Cluster I ( group B1) contains the majority of the strains and other pathotypes [enteroaggregative, enterotoxigenic and enterohemorrhagic E. coli ( EHEC)]; cluster II ( group A) also contains enteroaggregative and diffusely adherent E. coli; cluster III ( group B2) has atypical and typical EPEC possessing H6 or H34 antigen; and cluster IV ( group D) contains aEPEC O55:H7 strains and EHEC O157:H7 strains. PFGE analysis confirmed that these strains encompass a great genetic diversity. These results indicate that aEPEC clonal groups have a particular genomic background - especially the strains of phylogenetic group B1 that probably made possible the acquisition and expression of virulence factors derived from non-EPEC pathotypes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Attention deficit hyperactivity disorder (ADHD) is a clinically significant disorder in adulthood, but current diagnostic criteria and instruments do not seem to adequately capture the complexity of the disorder in this developmental phase. Accordingly, there are limited data on the proportion of adults affected by the disorder, specially in developing countries. Method: We assessed a representative household sample of the Brazilian population for ADHD with the Adult ADHD Self-report Scale (ASRS) Screener, and evaluated the instrument according to the Rasch model of item response theory. Results: The sample was comprised by 3007 individuals, and the overal prevalence of positive screeners for ADHD was 5.8% [95% confidence interval (CI), 4.8-7.0]. Rasch analyses revealed the misfitt of the overall sample to expectations of the model. The evaluation of the sample stratified by age revealed that data for adolescents showed a signficant fittnes to the model expectations, while items completed by adults were not adequated. Conclusions: The lack of fitness to the model for adult respondents challenges the possibility of a linear transformation of the ordinal data into interval measures and the utilization of parametric analyses of data. This result suggests that diagnostic criteria and instruments for adult ADHD must take into account a developmental perspective. Moreover, it calls for further evaluation of currently employed research methods in light of modern theories of psychometrics. Copyright (C) 2010 John Wiley & Sons, Ltd.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aims: The heterogeneity of the Brazilian population renders the extrapolation of pharmacogenomic data derived from well-defined ethnic groups inappropriate. We investigated the influence of self-reported `race/color`, geographical origin and genetic ancestry on the distribution of four VKORC1 SNPs and haplotypes in Brazilians. Comparative data were obtained from two major ancestral roots of Brazilians: Portuguese and Africans from former Portuguese colonies. Materials & methods: A total of 1037 healthy adults Brazilians, recruited at four different geographical regions and self identified as white, brown or black (race/color categories), 89 Portuguese and 216 Africans from Angola and Mozambique were genotyped for the VKORC1 3673G>A (rs9923231), 5808T>G (rs2884737), 6853G>C (rs8050894) and 9041G>A (rs7294) polymorphisms using TaqMan (R) (Applied Biosystems, CA, USA) assays. VKORC1 haplotypes were statistically inferred using the haplo.stats software. We inferred the statistical association between the distribution of the VKORC1 polymorphisms among Brazilians and self-reported color, geographical region and genetic ancestry by fitting multinomial log linear models via neural networks. Individual proportions of European and African ancestry were used to assess the impact of genetic admixture on the frequency distribution of VKORC1 polymorphisms among Brazilians, and for the comparison of Brazilians with Portuguese and Africans. Results: The frequency distribution of the 3673G>A and 5808T>G polymorphisms, and VKORC1 haplotypes among Brazilians varies across geographical regions, within self-reported color categories and according to the individual proportions of European and African genetic ancestry. Notably, the frequency of the warfarin sensitive VKORC1 3673A allele and the distribution of VKORC1 haplotypes varied continuously as the individual proportion of European ancestry increased in the entire cohort, independently of race/color categorization and geographical origin. Brazilians with more than 80% African ancestry differ significantly from Angolans and Mozambicans in frequency of the 3673G>A, 5808T>G and 6853G>C polymorphisms and haplotype distribution, whereas no such differences are observed between Brazilians with more than 90% European ancestry and Portuguese individuals. Conclusion: The diversity of the Brazilian population, evident in the distribution of VKORC1 polymorphisms, must be taken into account in the design of pharmacogenetic clinical trials and dealt with as a continuous variable. Warfarin dosing algorithms that include `race` terms defined for other populations are clearly not applicable to the heterogeneous and extensively admixed Brazilian population.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The impact of particle emissions by biomass burning is increasing throughout the world. We explored the toxicity of particulate matter produced by sugar cane burning and compared these effects with equivalent mass of traffic-derived particles. For this purpose, BALB/c mice received a single intranasal instillation of either distilled water (C) or total suspended particles (15 mu g) from an urban area (SP group) or biomass burning-derived particles (Bio group). Lung mechanical parameters (total, resistive and viscoelastic pressures, static elastance, and elastic component of viscoelasticity) and histology were analyzed 24h after instillation. Trace elements and polycyclic aromatic hydrocarbons (PAHs) metabolites of the two sources of particles were determined. All mechanical parameters increased similarly in both pollution groups compared with control, except airway resistive pressure, which increased only in Bio. Both exposed groups showed significantly higher fraction area of alveolar collapse, and influx of polymorphonuclear cells in lung parenchyma than C. The composition analysis of total suspended particles showed higher concentrations of PAHs and lower concentration of metals in traffic than in biomass burning-derived particles. In conclusion, we demonstrated that a single low dose of ambient particles, produced by traffic and sugar cane burning, induced significant alterations in pulmonary mechanics and lung histology in mice. Parenchymal changes were similar after exposure to both particle sources, whereas airway mechanics was more affected by biomass-derived particles. Our results indicate that biomass particles were at least as toxic as those produced by traffic. (C) 2008 Elsevier Inc. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The fruit of banana undergoes several important physico-chemical changes during ripening. Analysis of gene expression would permit identification of important genes and regulatory elements involved in this process. Therefore, transcript profiling of preclimacteric and climacteric fruit was performed using differential display and Suppression subtractive hybridization. Our analyses resulted in the isolation of 12 differentially expressed cDNAs, which were confirmed by dot-blots and northern blots. Among the sequences identified were sequences homologous to plant aquaporins, adenine nucleotide translocator, immunophilin, legumin-like proteins, deoxyguanosine kinase and omega-3 fatty acid desaturase. Some of these cDNAs correspond to newly isolated genes involved in changes related to the respiratory climacteric, or stress-defense responses. Functional characterization of ripening-associated genes could provide information useful in controlling biochemical pathways that would have an impact on banana quality and shelf life. (C) 2009 Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: The study compared the prevalence, correlates of functional impairment, and service utilization for eating disorders across Latinos, Asians, and African Americans living in the United States to non-Latino Whites. Method: Pooled data from the NIMH Collaborative Psychiatric Epidemiological Studies (CPES; NIMH, 2007) were used. Results: The prevalence of anorexia nervosa (AN) and binge-eating disorder (BED) were similar across all groups examined, but bulimia nervosa (BN) was more prevalent among Latinos and African Americans than non-Latino Whites. Despite similar prevalence of BED among ethnic groups examined, lifetime prevalence of any binge eating (ABE) was greater among each of the ethnic minority groups in comparison to non-Latino Whites. Lifetime prevalence of mental health service utilization was lower among ethnic minority groups studied than for non-Latino Whites for respondents with a lifetime history of any eating disorder. Discussion: These findings suggest the need for clinician training and health policy interventions to achieve optimal and equitable care for eating disorders across all ethnic groups in the United States. (C) 2010 by Wiley Periodicals, Inc.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Formoterol is a fast-acting, long-acting beta-agonist. Its on-demand use by outpatients has been beneficial in controlling asthma. Objective: To evaluate the efficacy of formoterol as rescue medication for pediatric asthma exacerbation. Methods: A randomized, double-blind study was conducted on parallel groups involving 79 pediatric patients (mean [SD] age, 9.92 [2.5] years) with mild to moderate asthma exacerbations. They were treated with up to 3 doses of formoterol aerolizer, 12 mu g, or terbutaline Turbuhaler, 0.5 mg (dry powder inhalers). Respiratory rate, clinical score, pulse oximetry, and spirometry were analyzed at baseline and 15 minutes after administration of each bronchodilator dose. All the patients received oral prednisolone, 1 mg/kg, at study entry, followed by a single daily dose for 4 days. Forty-one patients were treated with formoterol and 38 with terbutaline. The groups were comparable in age and in severity of asthma exacerbation. Results: Both treatments resulted in similar clinical and functional improvement; 37 patients (47%) required 1 bronchodilator dose. Increases of 19.5% and 1.5.3% occurred in forced expiratory volume in 1 second in the formoterol and terbutaline groups, respectively. Therapeutic failures occurred in 2 patients. No adverse effects were observed. At 1-week follow-up, patients were stable, with pulmonary function close to normal. Conclusion: Formoterol therapy was at least as effective as terbutaline therapy in children and adolescents with mild and moderate asthma exacerbations. Ann Allergy Asthma Immunol. 2009; 103:248-253.