Risk factors for infection with Giardia duodenalis in pre-school children in the city of Salvador, Brazil.

A cross-sectional study of 694 children aged 2 to 45 months selected from 30 clusters throughout the city of Salvador, Bahia (pop. 2.3 million) was carried out as part of a longitudinal study of diarrhoea in order to identify risk factors for infection with Giardia duodenalis. Variables studied included three social and demographic factors (such as mother's education and marital status), five relating to the peri-domestic environment (rubbish disposal, open sewers, paving of the street), seven relating to the home itself (house construction, susceptibility to flooding, water supply and sanitation) as well as a score for hygiene behaviour based on structured observation. After multivariate analysis using a hierarchical model, only four significant risk factors were found: (a) number of children in the household under five years (b) rubbish not collected from the house (c) presence of visible sewage nearby, and (d) absence of a toilet. All four were significant at the 1% level

Validation of a food frequency questionnaire for children and adolescents aged 4 to 11 years living in Salvador, Bahia.

OBJECTIVE: To assess the validity of a food frequency questionnaire (FFQ) by applying it to children and adolescents living in Salvador, Bahia. METHODS: The validity of this FFQ with 98 food items was investigated among 108 children and adolescents who were selected from a sample of 1445 that had been planned for a study on the risk factors for asthma and other allergic diseases. The adults responsible for these children and adolescents gave responses for a 24-hour recall (R24h) and an FFQ. The average energy and nutrient values from the FFQ were compared with those from the R24h by means of the paired t test and Pearson correlation coefficients. The concordance was evaluated using the Bland-Altman method and kappa statistics. RESULTS: The energy and nutrient intake estimated using the FFQ was significantly higher than what was obtained using the R24h. The correlation coefficients adjusted for energy were statistically significant for protein, fat, vitamin C and zinc. The weighted kappa values ranged from 0.06 for vitamin A (p = 0.24) to 0.34 for energy (p < 0.00). The results from the Bland-Altman plots for lipid, protein and zinc showed the most significant validity parameters, and zinc was found to show the best concordance. CONCLUSION: The results suggest that the FFQ showed satisfactory validity for use in studies involving children and adolescents

Coupled effect of microstructure and topology on the mechanical behavior of Inconel718 additively manufactured lattices

LPBF-manufactured Inconel718 lattices with six cubic and hexagonal structures and with two material microstructures (as-built, without γ” precipitation, and heat-treated, with γ” precipitates, but with similar cell/grain size, shape and texture) were compressed at room temperature and at 600 °C. The behavior of the base material under identical microstructure and test conditions was also investigated using dedicated LPBF-manufactured specimens with single strut gauges. Irrespective of topology, precipitation led to a transition in the lattice mechanical behavior from bending-dominated to stretch-dominated, which was associated to a change in the strut deformation mode from plastic hinging to elastic buckling, as well as to a decrease in the base material strain to fracture. For all topologies investigated, precipitation led to lattice strengthening, consistent with particle-strengthening of the base material. Additionally, high temperature straining resulted both in a decrease in the lattice yield strength, consistent with softening of the base material, and in a reduction in the width of the stress oscillations in the stretch-dominated lattices, which is associated to the decrease in the base material ductility. This work proves that material microstructure influences strongly the behavior of additively manufactured architectured structures and that it must be considered as a design criterion for performance optimization

Role of the employment status and education of mothers in the prevalence of intestinal parasitic infections in Mexican rural schoolchildren

&lt;p&gt;&lt;b&gt;Background:&lt;/b&gt; Intestinal parasitic infections are a public health problem in developing countries such as Mexico. As a result, two governmental programmes have been implemented: a) "National Deworming Campaign" and b) "Opportunities" aimed at maternal care. However, both programmes are developed separately and their impact is still unknown. We independently investigated whether a variety of socio-economic factors, including maternal education and employment levels, were associated with intestinal parasite infection in rural school children.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods:&lt;/b&gt; This cross-sectional study was conducted in 12 rural communities in two Mexican states. The study sites and populations were selected on the basis of the following traits: a) presence of activities by the national administration of albendazole, b) high rates of intestinal parasitism, c) little access to medical examination, and d) a population having less than 2,500 inhabitants. A total of 507 schoolchildren (mean age 8.2 years) were recruited and 1,521 stool samples collected (3 per child). Socio-economic information was obtained by an oral questionnaire. Regression modelling was used to determine the association of socio-economic indicators and intestinal parasitism.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Results:&lt;/b&gt; More than half of the schoolchildren showed poliparasitism (52%) and protozoan infections (65%). The prevalence of helminth infections was higher in children from Oaxaca (53%) than in those from Sinaloa (33%) (p &#60; 0.0001). Giardia duodenalis and Hymenolepis nana showed a high prevalence in both states. Ascaris lumbricoides, Trichuris trichiura and Entamoeba hystolitica/dispar showed low prevalence. Children from lower-income families and with unemployed and less educated mothers showed higher risk of intestinal parasitism (odds ratio (OR) 6.0, 95% confidence interval (CI) 1.6–22.6; OR 4.5, 95% CI 2.5–8.2; OR 3.3, 95% CI 1.5–7.4 respectively). Defecation in open areas was also a high risk factor for infection (OR 2.4, 95% CI 2.0–3.0).&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusion:&lt;/b&gt; Intestinal parasitism remains an important public health problem in Sinaloa (north-western Mexico) and Oaxaca (south-eastern Mexico). Lower income, defecation in open areas, employment status and a lower education level of mothers were the significant factors related to these infections. We conclude that mothers should be involved in health initiatives to control intestinal parasitism in Mexico.&lt;/p&gt

The SWR1 Histone Replacement Complex Causes Genetic Instability and Genome-Wide Transcription Misregulation in the Absence of H2A.Z

The SWR1 complex replaces the canonical histone H2A with the variant H2A.Z (Htz1 in yeast) at specific chromatin regions. This dynamic alteration in nucleosome structure provides a molecular mechanism to regulate transcription, gene silencing, chromosome segregation and DNA repair. Here we show that genetic instability, sensitivity to drugs impairing different cellular processes and genome-wide transcriptional misregulation in htz1Δ can be partially or totally suppressed if SWR1 is not formed (swr1Δ), if it forms but cannot bind to chromatin (swc2Δ) or if it binds to chromatin but lacks histone replacement activity (swc5Δ and the ATPase-dead swr1-K727G). These results suggest that in htz1Δ the nucleosome remodelling activity of SWR1 affects chromatin integrity because of an attempt to replace H2A with Htz1 in the absence of the latter. This would impair transcription and, either directly or indirectly, other cellular processes. Specifically, we show that in htz1Δ, the SWR1 complex causes an accumulation of recombinogenic DNA damage by a mechanism dependent on phosphorylation of H2A at Ser129, a modification that occurs in response to DNA damage, suggesting that the SWR1 complex impairs the repair of spontaneous DNA damage in htz1Δ. In addition, SWR1 causes DSBs sensitivity in htz1Δ; consistently, in the absence of Htz1 the SWR1 complex bound near an endonuclease HO-induced DSB at the mating-type (MAT) locus impairs DSB-induced checkpoint activation. Our results support a stepwise mechanism for the replacement of H2A with Htz1 and demonstrate that a tight control of this mechanism is essential to regulate chromatin dynamics but also to prevent the deleterious consequences of an incomplete nucleosome remodelling

Clinical safety of dichlorvos (45%), cypermethrin (5%) and piperonyl butoxide (25%) administered by spray on the skin of cattle

ABSTRACT Objective. Due to the importance of controlling ectoparasites, associated with the necessity of technical knowledge on the safety of topical treatment with organophosphates, pyrethroids and piperonyl butoxide to the animal organism, this bioassay was carried out to evaluate the clinical safety of the association of dichlorvos (45%) + cypermethrin (5%) + piperonyl butoxide (25%) administered by spray on the skin of cattle, through the study of clinical parameters, biochemical, haematological and behavioral changes. Materials and methods. Sixteen crossbred animals with a mean age of 18 months, males and females grouped into two treatments with eight animals each: T1 (1:800 v/v) and T2 (1:200 v/v). Were collected blood samples at six different times: before treatment (BT), 24, 48, 72, 96 and 192 hours post treatment (HPT). Results. The antiparasitic association administered by spray on the skin did not result in changes in the enzymatic activity of ALT, AST, GGT and ALP, as well as in serum albumin, triglycerides, cholesterol, urea and creatinine, demonstrating the safety of this antiparasitic compound for maintaining hepatic and renal functionality. The erythrocyte, leukocyte and platelet studies showed no changes caused by treatments, and no clinical signs and behavioral changes were observed after treatment. Conclusions. These findings demonstrated good safety margin for spray treatment on the skin with this antiparasitic compound, even when administered at a dilution of 1:200 v/v, which is four times the dose recommended for ectoparasite control

Reduced Expression of the Vesicular Acetylcholine Transporter and Neurotransmitter Content Affects Synaptic Vesicle Distribution and Shape in Mouse Neuromuscular Junction

In vertebrates, nerve muscle communication is mediated by the release of the neurotransmitter acetylcholine packed inside synaptic vesicles by a specific vesicular acetylcholine transporter (VAChT). Here we used a mouse model (VAChT KDHOM) with 70% reduction in the expression of VAChT to investigate the morphological and functional consequences of a decreased acetylcholine uptake and release in neuromuscular synapses. Upon hypertonic stimulation, VAChT KDHOM mice presented a reduction in the amplitude and frequency of miniature endplate potentials, FM 1-43 staining intensity, total number of synaptic vesicles and altered distribution of vesicles within the synaptic terminal. In contrast, under electrical stimulation or no stimulation, VAChT KDHOM neuromuscular junctions did not differ from WT on total number of vesicles but showed altered distribution. Additionally, motor nerve terminals in VAChT KDHOM exhibited small and flattened synaptic vesicles similar to that observed in WT mice treated with vesamicol that blocks acetylcholine uptake. Based on these results, we propose that decreased VAChT levels affect synaptic vesicle biogenesis and distribution whereas a lower ACh content affects vesicles shape

A New Approach for Adipose Tissue Treatment and Body Contouring Using Radiofrequency-Assisted Liposuction

A new liposuction technology for adipocyte lipolysis and uniform three-dimensional tissue heating and contraction is presented. The technology is based on bipolar radiofrequency energy applied to the subcutaneous adipose tissue and subdermal skin surface. Preliminary clinical results, thermal monitoring, and histologic biopsies of the treated tissue demonstrate rapid preaspiration liquefaction of adipose tissue, coagulation of subcutaneous blood vessels, and uniform sustained heating of tissue

Do brain networks evolve by maximizing their information flow capacity?

We propose a working hypothesis supported by numerical simulations that brain networks evolve based on the principle of the maximization of their internal information flow capacity. We find that synchronous behavior and capacity of information flow of the evolved networks reproduce well the same behaviors observed in the brain dynamical networks of Caenorhabditis elegans and humans, networks of Hindmarsh-Rose neurons with graphs given by these brain networks. We make a strong case to verify our hypothesis by showing that the neural networks with the closest graph distance to the brain networks of Caenorhabditis elegans and humans are the Hindmarsh-Rose neural networks evolved with coupling strengths that maximize information flow capacity. Surprisingly, we find that global neural synchronization levels decrease during brain evolution, reflecting on an underlying global no Hebbian-like evolution process, which is driven by no Hebbian-like learning behaviors for some of the clusters during evolution, and Hebbian-like learning rules for clusters where neurons increase their synchronization