The Effect of a Linear Tuning between the Antigenic Stimulations of CD4(+) T Cells and CD4(+) Tregs

We study the equilibria of an Ordinary Differencial Equation (ODE) system where CD4+ effector or helper T cells and Regulatory T cells (Tregs) are present. T cells trigger an immune response in the presence of their specific antigen. Regulatory T cells (Tregs) play a role in limiting auto-immune diseases due to their immune-suppressive ability. Here, we present explicit exact formulas that give the relationship between the concentration of T cells, the concentration of Tregs, and the antigenic stimulation of T cells, when the system is at equilibria, stable or unstable. We found a parameter region of bistability, limited by two thresholds of antigenic stimulation of T cells (hysteresis). Moreover, there are values of the slope parameter of the tuning for which an isola-center bifurcation appears, and, for some other values, there is a transcritical bifurcation. We also present time evolutions of the ODE system

SEROLOGIC SURVEY ON HANTAVIRUS IN BLOOD DONORS FROM THE STATE OF SANTA CATARINA, BRAZIL

Emergent diseases such as Hantavirus Cardio-pulmonary Syndrome (HCPS) are able to create a significant impact on human populations due to their seriousness and high fatality rate. Santa Catarina, located in the South of Brazil, is the leading state for HCPS with 267 reported cases from 1999 to 2011. We present here a serological survey on hantavirus in blood donors from different cities of the state of Santa Catarina, with an IgG-ELISA using a recombinant nucleocapsid protein from Araraquara hantavirus as an antigen. In total, 314 donors from blood banks participated in the study, geographically covering the whole state. Among these, 14 individuals (4.4%) had antibodies to hantavirus: four of 50 (8% positivity) from Blumenau, four of 52 (7.6%) from Joinville, three of 50 (6%) from Florianópolis, two of 50 (4%) from Chapecó and one of 35 (2.8%) from Joaçaba. It is possible that hantaviruses are circulating across almost the whole state, with important epidemiological implications. Considering that the seropositive blood donors are healthy individuals, it is possible that hantaviruses may be causing unrecognized infections, which are either asymptomatic or clinically nonspecific, in addition to HCPS. It is also possible that more than one hantavirus type could be circulating in this region, causing mostly benign infections

Age differences in the use of implicit visual cues in a response time task

Background: Many activities require a complex interrelationship between a performer and stimuli available in the environment without explicit perception, but many aspects regarding developmental changes in the use of implicit cues remain unknown. Aim: To investigate the use of implicit visual precueing presented at different time intervals in children, adolescents, and adults. Method: Seventy-two people, male and female, constituted four age groups: 8-, 10- and 12-year-olds and adults. Participants performed 32 trials, four-choice-time task across four conditions: no precue and a 43 ms centralized dot appearing in the stimulus circle at 43, 86 or 129 ms prior the stimulus. Response times were obtained for each trial and pooled into each condition. Results: Response times for 8-year-olds were longer than for 12-year-olds and adults and for 10-year-olds were longer than for adults. Response times were longer in the no precue condition compared to when precues were presented at 86 and 129 ms before the stimulus. Response times were longer when precue was presented at 43 ms compared presented at 129 ms before the stimulus. Interpretation: Implicit precues reduce response time in children, adolescents and adults, but young children benefit less from implicit precues than adolescents and adults.</jats:p

Data on prevalence and risk factors associated with Toxocara spp infection, atopy and asthma development in Northeast Brazilian school children.

In the present article, we provide shortly, data on risk factors for acquiring Toxocara spp. infection and investigate possible associations between this infection with atopy and asthma in school children of a small town and its semi-rural areas of Northeast Brazil. The data set are composed by demographic, social and home environment variables. The detection of anti-Toxocara spp. IgG and specific IgE to aeroallergens was determined by ELISA and ImmunocAP/Phadiatrope systems, respectively. The data presented in this article are related to the article entitled "Risk factors for Toxocara spp. seroprevalence and its association with atopy and asthma phenotypes in school-age children in a small town and semi-rural areas of Northeast Brazil" (M.B. Silva, A.L. Amor, L.N. Santos, A.A. Galvão, A.V. Oviedo Vera, E.S. Silva et al., 2016) [1]

Mass hierarchy, mass gap and corrections to Newton's law on thick branes with Poincare symmetry

We consider a scalar thick brane configuration arising in a 5D theory of gravity coupled to a self-interacting scalar field in a Riemannian manifold. We start from known classical solutions of the corresponding field equations and elaborate on the physics of the transverse traceless modes of linear fluctuations of the classical background, which obey a Schroedinger-like equation. We further consider two special cases in which this equation can be solved analytically for any massive mode with m^2>0, in contrast with numerical approaches, allowing us to study in closed form the massive spectrum of Kaluza-Klein (KK) excitations and to compute the corrections to Newton's law in the thin brane limit. In the first case we consider a solution with a mass gap in the spectrum of KK fluctuations with two bound states - the massless 4D graviton free of tachyonic instabilities and a massive KK excitation - as well as a tower of continuous massive KK modes which obey a Legendre equation. The mass gap is defined by the inverse of the brane thickness, allowing us to get rid of the potentially dangerous multiplicity of arbitrarily light KK modes. It is shown that due to this lucky circumstance, the solution of the mass hierarchy problem is much simpler and transparent than in the (thin) Randall-Sundrum (RS) two-brane configuration. In the second case we present a smooth version of the RS model with a single massless bound state, which accounts for the 4D graviton, and a sector of continuous fluctuation modes with no mass gap, which obey a confluent Heun equation in the Ince limit. (The latter seems to have physical applications for the first time within braneworld models). For this solution the mass hierarchy problem is solved as in the Lykken-Randall model and the model is completely free of naked singularities.Comment: 25 pages in latex, no figures, content changed, corrections to Newton's law included for smooth version of RS model and an author adde

Inflamación crónica granulomatosa en el pez teleósteo Piaractus mesopotamicus: modelo de estudio histopatológico

Objective. This study evaluated the cell kinetic and formation of granuloma during chronic inflammation induced by Bacillus Calmette-Guérin (BCG) in the skeletal muscle of Piaractus mesopotamicus, as a histopathology model to study innate immunity. Materials and methods. Sixty fish were divided in two groups: BCG-inoculated and non-inoculated fish and the inflammatory response analyzed 3, 7, 14, 21 and 33 days post-inoculation (DPI) by histopathology after hematoxylin-eosin and Ziehl-Neelsen staining. Results. 3 DPI of BCG showed a diffuse inflammatory reaction mostly composed by mononuclear cells. The inflammation continued diffuse 7 DPI initiating the cellular organization surrounding the inoculum and have continued at 14 DPI with discrete presence of epithelioid-like type cells with acidophilic cytoplasm and floppy chromatin. Higher cellular organization (21 DPI) surrounding the granuloma with intense peripheral mononuclear inflammatory infiltrate and nevertheless, an increase in the number of fibroblasts and macrophage-like cells was observed. The inflammatory process became less diffuse 33 DPI with formation of small amount of granuloma surrounded by the same type of reaction found in bigger granuloma. Both the young and old granuloma presented typical characteristic around the inoculum composed by a layer of epithelioid-like type cells, besides macrophages, some lymphocytes and abundant fibroblasts. Conclusions. This study showed the feasibility in the use of pacus to study chronic granulomatous inflammatory response induced by BCG, characterized by changes in the kinetics of inflammatory cells in skeletal muscle classifying as immune-epithelioid type, similar to granulomatous inflammation caused by M. marinum in teleost fish.Objetivo. Este estudio evaluó la cinética celular y la formación de granuloma durante la inflamación crónica inducida por el Bacilo Calmette-Guérin (BCG) en el músculo esquelético de Piaractus mesopotamicus, como modelo histopatológico para estudiar la inmunidad innata. Materiales y métodos. Sesenta peces fueron divididos en dos grupos: peces inoculados con BCG y no inoculados y la respuesta inflamatoria analizada en 3, 7, 14, 21 y 33 días post-inóculo (DPI) por medio del análisis histopatológico y tinciones de hematoxilina-eosina y Ziehl-Neelsen. Resultados. 3 DPI de BCG se observó reacción inflamatoria difusa principalmente formada por infiltrado celular mononuclear. Al 7° DPI la inflamación continuaba difusa con inicio de organización celular alrededor del inoculo, que se observó hasta el 14° DPI con discreta presencia de células de tipo epiteliodes con citoplasma acidófilo y cromatina laxa. Para el 21° DPI se observó alta organización celular alrededor del granuloma con intenso infiltrado mononuclear periférico e incremento en el número de fibroblastos y macrófagos. El proceso inflamatorio se tornó menos difuso a los 33 DPI con formación de pequeños granulomas contenidos dentro de uno más grande. Los granulomas formados más rápidamente así como los formados tardíamente, presentaron características típicas alrededor del inóculo compuesta por una camada de células tipo epitelioides, macrófagos, linfocitos y fibroblastos. Conclusiones. Este estudio mostró la viabilidad del uso del P. mesopotamicus para estudiar la respuesta inflamatoria crónica granulomatosa inducida con BCG, caracterizado por la evolución de la cinética de células inflamatorias en el músculo esquelético clasificándolo como de tipo inmune-epitelioide, similar a la inflamación granulomatosa causada por M. marinum en peces teleósteos

Understanding asthma phenotypes: the World Asthma Phenotypes (WASP) international collaboration.

The World Asthma Phenotypes (WASP) study started in 2016 and has been conducted in five centres, in the UK, New Zealand, Brazil, Ecuador and Uganda. The objectives of this study are to combine detailed biomarker and clinical information in order to 1) better understand and characterise asthma phenotypes in high-income countries (HICs) and low and middle-income countries (LMICs), and in high and low prevalence centres; 2) compare phenotype characteristics, including clinical severity; 3) assess the risk factors for each phenotype; and 4) assess how the distribution of phenotypes differs between high prevalence and low prevalence centres. Here we present the rationale and protocol for the WASP study to enable other centres around the world to carry out similar analyses using a standardised protocol. Large collaborative and integrative studies like this are essential to further our understanding of asthma phenotypes. The findings of this study will help elucidate the aetiological mechanisms of asthma and might potentially identify new causes and guide the development of new treatments, thereby enabling better management and prevention of asthma in both HICs and LMICs

IDENTIFICATION OF CANINE VISCERAL LEISHMANIASIS IN A PREVIOUSLY UNAFFECTED AREA BY CONVENTIONAL DIAGNOSTIC TECHNIQUES AND CELL-BLOCK FIXATION

After the report of a second case of canine visceral leishmaniasis (CVL) in São Bento da Lagoa, Itaipuaçu, in the municipality of Maricá, Rio de Janeiro State, an epidemiological survey was carried out, through active search, totaling 145 dogs. Indirect immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA), and rapid chromatographic immunoassay based on dual-path platform (DPP(r)) were used to perform the serological examinations. The parasitological diagnosis of cutaneous fragments was performed by parasitological culture, histopathology, and immunohistochemistry. In the serological assessment, 21 dogs were seropositive by IFA, 17 by ELISA, and 11 by DPP(r), with sensitivity of 66.7%, 66.7% and 50%, and specificity of 87.2%, 90.2% and 94%, respectively for each technique. The immunohistochemistry of bone marrow using the cell-block technique presented the best results, with six positive dogs found, three of which tested negative by the other parasitological techniques. Leishmania sp. was isolated by parasitological culture in three dogs. The detection of autochthonous Leishmania infantum in Itaipuaçu, and the high prevalence of seropositive dogs confirm the circulation of this parasite in the study area and alert for the risk of expansion in the State of Rio de Janeiro

Dengue fever: a post-epidemic sero-epidemiological survey in an urban setting at a northwestern county of S. Paulo State - Brazil

Objective The objective of this study was to evaluate the real size of the epidemics registered in thr urban area of the county of Santa Barbara D'Oeste, SP Brazil, from April to June, 1995. The measurement of the epidemiological validity of the official surveillance system criteria and its positive predicted value It were adopted as specific goals. Methods A sero-epidemiological sun,ey was carried out over a sample of 1,113 sera from citizens of Santa Barbara D'Oeste, through a systematic random sampling of houses, five months after the end of the epidemics. Infection rates were compared with the infestation indexes by Aedes aegipty and the notified cases amongst the county sections. The importance of submitting patients with clinical suspicion of dengue to laboratory rests was discussed. Results and Discussion it was found that infection rates by dengue virus varied in the same direction and proportion as the presence of Aedes aegipty larvae reported by the 'Breteau Index', as well as the number of cases,reported by the official notifiable diseases surveillance system during the epidemics. A prevalence of 630 by 100 thousand inhabitants was found, a 15-fold rate when compared to rite laboratory positive sera from cases detected by the surveillance system during the epidemics. A retrospective comparison with the surveillance reports, using serological results as a gold standard, also showed that the majority of dengue specific serum-positive individuals were not detected during the epidemics. otherwise cases that did not present serological reaction were notified exhibiting a low positive predictive value of clinical diagnosis (15,6).33656657