P2X4 receptors interact with both P2X2 and P2X7 receptors in the form of homotrimers

BACKGROUND AND PURPOSE The P2X receptor family consists of seven subunit types - P2X1-P2X7. All but P2X6 are able to assemble as homotrimers. In addition, various subunit permutations have been reported to form heterotrimers. Evidence for heterotrimer formation includes co-localization, co-immunoprecipitation and the generation of receptors with novel functional properties; however, direct structural evidence for heteromer formation, such as chemical cross-linking and single-molecule imaging, is available in only a few cases. Here we examined the nature of the interaction between two pairs of subunits - P2X2 and P2X4, and P2X4 and P2X7. EXPERIMENTAL APPROACH We used several experimental approaches, including in situ proximity ligation, co-immunoprecipitation, co-isolation on affinity beads, chemical cross-linking and atomic force microscopy (AFM) imaging. KEY RESULTS Both pairs of subunits co-localize upon co-transfection, interact intimately within cells, and can be co-immunoprecipitated and co-isolated from cell extracts. Despite this, chemical cross-linking failed to show evidence for heteromer formation. AFM imaging of isolated receptors showed that all three subunits had the propensity to form receptor dimers. This self-association is likely to account for the observed close interaction between the subunit pairs, in the absence of true heteromer formation. CONCLUSIONS AND IMPLICATIONS We conclude that both pairs of receptors interact in the form of distinct homomers. We urge caution in the interpretation of biochemical evidence indicating heteromer formation in other cases.

The impact of perinatal and socioeconomic factors on mental health problems of children from a poor Brazilian city: a longitudinal study

Low birth weight and preterm birth, and social disadvantage may negatively affect mental health of children, but findings have been inconsistent. To assess the influence of perinatal and social factors on mental health problems in children aged 7-9 years. A random sample of 805 births in So Luis, Brazil was studied in 1997/1998 and again in 2005/2006. Perinatal, socioeconomic and demographic variables were assessed within 24 h after delivery. The Strengths and Difficulties Questionnaire (SDQ) was used to assess mental health problems in the children. Simple and multiple Poisson regressions were used for statistical analysis. The overall prevalence of mental health problems in the total sample was 47.7%. The prevalences of emotional and conduct problems were 58.2 and 48.8%, respectively. Only paternal age (< 20 years) was associated with mental health problems as measured by the full SDQ scale (prevalence ratio PR = 1.27). Children born to single mothers (PR = 1.31) and those with birth weight from 1,500 to 2,499 g (PR = 1.18) and from 2,500 to 2,999 g (PR = 1.17) had a higher risk of emotional problems, but those from low income families had a lower risk (PR = 0.80). Children with a father of less than 20 years had a higher risk of having problems with their peers (PR = 1.75). A maternal education of 9 years or over was inversely associated with peer (PR = 0.70) and conduct problems (PR = 0.73). Girls had a lower risk of conduct (PR = 0.77) and hyperactivity problems (PR = 0.68). A maternal education of 4 years or less increased the risk of hyperactivity (PR = 1.48). Socioeconomic and demographic conditions were better predictors of mental health problems in children than birth weight or preterm birth. However, since most effect sizes were small most mental health problems were, unexplained by the variables in the study.

Age-related deregulation of Aire and peripheral tissue antigen genes in the thymic stroma of non-obese diabetic (NOD) mice is associated with autoimmune type 1 diabetes mellitus (DM-1)

Gene expression of peripheral tissue antigens (PTAs) in stromal medullary thymic epithelial cells (mTECs) is a key process to the negative selection of autoreactive thymocytes. This phenomenon was termed ""promiscuous gene expression"" (PGE), which is partially controlled by the Aire gene. Nevertheless, reasons for the correlation of Aire and PTAs with the emergence of autoimmune diseases are largely unknown, though it may be a result of a chronological effect. Although the effect of Aire mutations in pathogenic autoimmunity is well know, it could not be a unique cause for autoimmunity. Independently of mutations, temporal deregulation of Aire expression may imbalance Aire-dependent PTAs and/or wide PGE. This deregulation may be an early warning sign for autoimmune diseases as it guarantees autoantigen representation in the thymus. To assess this hypothesis, we studied the expression levels of Aire, Aire-dependent (Ins2) and Aire-independent (Gad67 and Col2a1) PTAs using real-time-PCR of the thymic stromal cells of NOD mice during the development of autoimmune type 1 diabetes mellitus (DM-1). Wide PGE was studied by microarrays in which the PTA genes were identified through parallel CD80(+) mTEC 3.10 cell line expression profiling. The results show that Aire gene was down-regulated in young pre-autoimmune (pre-diabetic) NOD mice. PGE and specific PTA genes were down-regulated in adult autoimmune diabetic animals. These findings represent evidence indicating that chronological deregulation of genes important to negative selection may be associated with the development of an autoimmune disease (DM-1) in mice.

Education's role in economic development and in assisting the poor

Much faith has been put in the increased supply of education as a means to promote national economic development and as a way to assist the poor and the disadvantaged. However, the benefits that nations can obtain by increasing the level of education of their workforce depends on the availability of other forms of capital to complement the use of its educated workforce in production. Generally, less developed nations are lacking in complementary capital compared to more developed ones and it is appropriate for less developed countries to spend relatively less on education. The contribution of education to economic growth depends on a nation’s stage of economic development. It is only when a nation becomes relatively developed that education becomes a major contributor to economic growth. It is possible for less developed nations to retard their economic growth by favouring investment in educational capital rather than other forms of capital. Easy access to education is often portrayed as a powerful force for assisting the poor and the disadvantaged. Several reasons are given here as to why it may not be so effective in assisting the poor and in promoting greater income equality even though the aim is a worthy one. Also, an economic argument is presented in favour of special education for the physically and mentally handicapped. This paper is not intended to belittle the contribution of education to economic development nor to devalue the ideal of making basic education available to all. Instead, it is intended as an antidote to inflated claims about the ability of greater investment in education to promote economic growth and about the ability of more widespread access to education to reduce poverty and decrease income inequality.

Guidelines for the treatment of postmenopausal osteoporosis for general practitioners

BACKGROUND: Osteoporosis Australia has been committed to the education of general practitioners and the community with a series of updated guidelines on the management of osteoporosis. Since the last series was published in Australian Family Physician (August 2000), there have been further advances in our understanding of the treatments involved in both prevention of bone loss and the management of established osteoporosis. OBJECTIVE: This article represents updated guidelines for the treatment of postmenopausal osteoporosis to assist GPs identify those women at risk and to review current treatment strategies. DISCUSSION: Osteoporosis and its associated problems are major health concerns in Australia, especially with an aging population. While important principles of management are still considered to be maximising peak bone mass and preventing postmenopausal bone loss, new clinical trial data about drugs such as the bisphosphonates, raloxifene and oestrogen have recently become available and the relative role of various agents is gradually becoming clearer. The use of long term hormone replacement therapy has mixed risks and benefits that requires individual patient counselling.

Attitudes and practices of general practitioners in the diagnosis and management of attention-deficit/hyperactivity disorder

Objective: To assess understanding of, and actual and potential roles in management of attention-deficit/hyperactivity disorder (ADHD) among GPs. Methods: A cross-sectional questionnaire survey of Queensland GPs selected randomly from the Royal Australian College of General Practitioners directory of members was carried out. Main outcome measures were knowledge levels of ADHD, current management practices, referral patterns and self-perceived information and training needs. Results: Three hundred and ninety-nine GPs returned a completed questionnaire (response rate 76%). Roles identified by GPs were: the provisional diagnosis of ADHD and referral to specialist services for confirmation of the diagnosis and initiation of management; assistance with monitoring progress once a management plan was in place; education of the child and their family regarding the disorder; and liaison with the school where necessary. Perceived barriers to increased involvement of GPs were: time and resource constraints of general practice; concerns regarding abuse and addiction liability of prescription stimulants; complex diagnostic issues associated with childhood behavioural problems; and lack of training and education regarding ADHD. Conclusions: General practitioners identify a role for themselves in ADHD care that is largely supportive in nature and involves close liaison with specialist services.

The use and relevance of gonad protection shields in children during hips radiography

Considering that ionizing radiation effects are cumulative and the gonads are particularly sensitive to these effects, and also the clinical importance of pelvic radiographs in children, the excess of radiation exposure to the gonads must be avoided. The purpose of this study is to demonstrate the relevance of the correct use of gonad protection shields and to evaluate their use on the hip radiographs performed in a reference clinical institution, through the retrospective analysis of pelvic radiographic images performed in children. According the image quality assessment, 20 (40%) patients were unprotected and gonads shields were incorrectly placed in 24 (80%) patients.

Helmet use among motorcyclists: observational study in the city of Mar del Plata, Argentina

The objective of the study was to assess the use of helmets in a community where helmet use is mandatory but low as there is no police enforcement. A sample comprising 451 motorcyclists in the city of Mar del Plata, Argentina, was studied in 2006. The following variables were studied: gender, type of motorcycle, weather conditions, time of the day, city area and type of road where motorcyclists traveled. Data were analyzed through a multiple logistic regression model. An overall 40% prevalence (95% CI: 35.5;44.5) of helmet use was found. Higher rates of helmet use were seen among women, and under unfavorable weather conditions, lower rates were found in the city outskirts, and variable use was seen according to the type of motorcycle. There is a need to improve law enforcement and to promote education of motorcyclists.

TRAILER Project (Tagging, Recognition, Acknowledgment of Informal Learning Experiences) a methodology to make learners' informal learning activities visible to the institutions

The application of information technologies (specially the Internet, Web 2.0 and social tools) make informal learning more visible. This kind of learning is not linked to an institution or a period of time, but it is important enough to be taken into account. On the one hand, learners should be able to communicate to the institutions they are related to, what skills they possess, whether they were achieved in a formal or informal way. On the other hand the companies and educational institutions need to have a deeper knowledge about the competencies of their staff. The TRAILER project provides a methodology supported by a technological framework to facilitate communication about informal learning between businesses, employees and learners. The paper presents the project and some of the work carried out, an exploratory analysis about how informal learning is considered and the technological framework proposed. Whilst challenges remain in terms of establishing the meaningfulness of technological engagement for employees and businesses, the continuing transformation of the social, technological and educational environment is likely to lead to greater emphasis for the effective exploitation of informal learning.

Studying the impact of co-authorship with external researchers:the case of research community in Portugal using social network analysis.

Project work presented as a partial requirement to obtain a Master Degree in Information Management

Serologic survey of hantavirus in a rural population from the northern State of Mato Grosso, Brazil

INTRODUCTION: Hantavirus is a genus of ribonucleic acid (RNA) viruses included in the family Bunyaviridae. Hantaviruses are rodent-borne zoonoses that, in the last 18 years, became an emergent public health problem in the Americas, causing a severe cardiopulmonary syndrome. This disease has no specific treatment and has a high case fatality. The transmission of hantavirus to man occurs by inhaling aerosols of rodent excreta. The aim of this study was to determine the prevalence of antibodies to hantavirus in the population of the rural settlement of Tupã in the county of Marcelândia, state of Mato Grosso, Brazil. METHODS: The participants of the serologic survey were visited at their homes and selected randomly among the settlement population. Blood samples of the participants were collected by venopuncture. The serum samples were tested by an IgG-ELISA using an N recombinant protein of Araraquara hantavirus as antigen, using the protocol previously established by Figueiredo et al. RESULTS: IgG antibodies to hantavirus were detected in 7 (13%) of the 54 participants. The positivity was higher among men. It was observed that there was an association of seropositivity to hantavirus within the participants born in the south of Brazil. CONCLUSIONS: The results suggest that, in this rural area, everyone is exposed to the same risk of becoming infected with hantavirus, and, therefore, there is a need to intensify surveillance activities and education of the local people to prevent this viral infection.

Spatial distribution of trachoma cases in the City of Bauru, State of São Paulo, Brazil, detected in 2006: defining key areas for improvement of health resources

IntroductionThe objective of this study was to analyze the spatial behavior of the occurrence of trachoma cases detected in the City of Bauru, State of São Paulo, Brazil, in 2006 in order to use the information collected to set priority areas for optimization of health resources.Methodsthe trachoma cases identified in 2006 were georeferenced. The data evaluated were: schools where the trachoma cases studied, data from the 2000 Census, census tract, type of housing, water supply conditions, distribution of income and levels of education of household heads. In the Google Earth® software and TerraView® were made descriptive spatial analysis and estimates of the Kernel. Each area was studied by interpolation of the density surfaces exposing events to facilitate to recognize the clusters.ResultsOf the 66 cases detected, only one (1.5%) was not a resident of the city's outskirts. A positive association was detected of trachoma cases and the percentage of heads of household with income below three minimum wages and schooling under eight years of education.ConclusionsThe recognition of the spatial distribution of trachoma cases coincided with the areas of greatest social inequality in Bauru City. The micro-areas identified are those that should be prioritized in the rationalization of health resources. There is the possibility of using the trachoma cases detected as an indicator of performance of micro priority health programs.

Survey of Bancroftian filariasis infection in humans and Culex mosquitoes in the western Brazilian Amazon region: implications for transmission and control

IntroductionThe aim of this work was to identify possible lymphatic filariasis foci in the western Brazilian Amazonian that could be established from the reports of Rachou in the 1950s. The study was conducted in three cities of the western Brazilian Amazon region - Porto Velho and Guajará-Mirim (State of Rondônia) and Humaitá (State of Amazonas).MethodsFor human infection evaluation thick blood smear stained with Giemsa was used to analyze samples collected from 10pm to 1am. Polymerase chain reaction (PCR) was used to examine mosquito vectors for the presence of Wuchereria bancrofti DNA. Humans were randomly sampled from night schools students and from inhabitants in neighborhoods lacking sanitation. Mosquitoes were collected from residences only.ResultsA total 2,709 night students enrolled in the Program for Education of Young Adults (EJA), and 935 people registered in the residences near the schools were examined, being 641 from Porto Velho, 214 from Guajará-Mirim and 80 from Humaitá. No individual examined was positive for the presence of microfilariae in the blood stream. A total of 7,860 female Culex quinquefasciatus specimens examined were negative by PCR.ConclusionsThis survey including human and mosquito examinations indicates that the western Amazon region of Brazil is not a focus of Bancroftian filariasis infection or transmission. Therefore, there is no need to be included in the Brazilian lymphatic filariasis control program.

School governance and academic excellence: the representations of distinguished students in an annual award of excellence

Within a research project on «academic excellence in the state school», this paper is a contribution to the sociological reflection on the cultural and organisational characteristics of the school and its relationship with the academic success of students. The data we present stem from a case study underway at a secondary school in the north of Portugal, referring to the universe of students that since 2003 have distinguished themselves for achieving grades equal to or greater than 18 (on a scale of 0 to 20) and have thus been included in the school’s Framework of Excellence. From a contextual approach to this educational practice, we focused on the cultural characteristics of the school/subject as analytical support for the study of school and non-school dimensions in their mutual connections. To this end, we used the information from document analysis and data collected from a questionnaire survey administered to more than two-thirds of the students included in the above-mentioned Framework of Excellence. Subsequently, we will use the data from this survey to understand the extent to which academic excellence is perceived as an indivisible social construction of the school’s political and organisational matrix, particularly in terms of the educational and teaching guidelines adopted by the management body. We will conclude by questioning the meaning of the school’s management policies regarding the emphasis on educational outcomes, with particular focus on the representations of excellent students in the processes of school leadership, teaching organisation, school merit and justice.

Evaluation of the morphological and physical characteristics of plumes from chicken feathers

This work presents a study on the properties of chicken plumes from the poultry industry, namely feathers. Studies conducted include length, diameter and weight of chicken feathers to 42 days old. Initial results indicate that the central and lower feather areas present very interesting properties and characteristics turning these materials suitable for various applications, including in clothing, thermal and acoustic insulation in buildings, cimenticious and polymeric matrices reinforcements, among others.