IL33 and IL1RL1 variants are associated with asthma and atopy in a Brazilian population.

Atopic asthma is a chronic inflammatory disease in airways resulting from genetic and environmental factors, characterized by production of the Th2 cytokines interleukin-4 (IL-4), interleukin-5 (IL-5) and interleukin-13 (IL-13). Interleukin-33 (IL-33) appears to be a potent inducer of Th2 immune response. This occurs when IL-33 binds and activates its receptor, the membrane ST2 (ST2L) in mast cells, dendritic cells, basophils, eosinophils, innate lymphoids and Th2 cells, leading to the release of these cytokines and intensifying allergic inflammation. Polymorphisms in the IL33 and IL1RL1 can act as protective or risk factors for asthma and/or allergy in humans. No study was conducted to replicate such findings in a European and African descendent mixed population. DNA was extracted from peripheral blood from 1223 subjects, and the samples were genotyped using Illumina 2.5 Human Omni Beadchip. We tested for possible associations between SNPs in the IL33 and ST2 with asthma and allergy markers such as specific IgE (sIgE), IL-5 and IL-13 production and skin prick test (SPT). Logistics regressions were performed using PLINK software 1.07. The analyses were adjusted for sex, age, helminth infection and ancestry markers. The G allele of IL33 SNP rs12551256 was negatively associated with asthma (OR 0.71, 95% CI: 0.53-0.94, P = 0.017). In contrast, the A allele of IL1RL1 rs1041973 was positively associated with IL-5 production (OR 1.36, 95% CI: 1.09-1.84, P = 0.044), sIgE levels (OR 1.40, 95% CI: 1.07-1.84, P = 0.013) and positive SPT (OR 1.48, 95% CI: 1.08-2.03, P = 0.014), for Blomia tropicalis mite. The same allele, in atopic subjects, was associated with decreased production of soluble ST2 (sST2) (P < 0.05). Moreover, expression quantitative trait loci (eQTL) analysis suggests that rs1041973 and rs873022 regulate the expression of IL1RL1 gene. This latest SNP, rs873022, the T allele, was also associated with a lower production of sST2 in plasma of Brazilians. The genetic risk score for rs1041973 and rs16924161 demonstrated a higher risk for SPT positivity against B. tropicalis, the greater the number of risk alleles for both SNPs. Our findings demonstrate a robust association of genetic variants in IL1RL1 and IL33 SNPs with allergy markers and asthma.

Detection of parasite antigens in Leishmania infantum-infected spleen tissue by monoclonal antibody-, piezoelectric-based immunosensors.

Diseases such as leishmaniases are important causes of morbidity and mortality in Brazil, and their diagnoses need to be improved. The use of monoclonal antibodies has ensured high specificity to immunodiagnosis. The development of an immunosensor, coupling a monoclonal antibody to a bioelectronic device capable of quickly detecting Leishmania sp. antigens both qualitatively and quantitatively, is a promising alternative for the diagnosis of leishmaniasis due to its high specificity, low cost, and portability, compared with conventional methods. The present work was aimed at developing an immunosensor-based assay for detecting Leishmania infantum antigens in tissues of infected hosts. Four hybridomas producing monoclonal antibodies against L. infantum had their specificity confirmed by enzyme-linked immunosorbent assay. These antibodies were immobilized on a gold surface, covered with a thin film of 2-aminoethanethiol (cysteamine) and glutaraldehyde, blocked with glycine, and placed into contact with extracts of L. infantum -infected and noninfected control hamster spleens. The assay was able to detect 1.8 × 10(4) amastigotes/g of infected tissue. These results demonstrated that this assay may be useful for quantifying L. infantum amastigotes in organs of experimental animals for studies on pathogenesis and immunity and that it is a promising tool for the development of a diagnostic method, based on antigen detection, of human and dog visceral leishmaniasis.

A proteomic approach to identify proteins from Trichuris trichiura extract with immunomodulatory effects.

Infections with Trichuris trichiura and other trichurid nematodes have been reported to display protective effects against atopy, allergic and autoimmune diseases. The aims of the present study were to investigate the immunomodulatory properties of T. trichiura adult worm extract (TtE) and its fractions (TtEFs) on the production of cytokines by peripheral blood mononuclear cells and to identify their proteinaceous components. Fourteen TtEFs were obtained by ion exchange chromatography and tested for effects on cytokine production by peripheral blood mononuclear cells. The molecular constituents of the six most active fractions were evaluated using nano-LC/mass spectrometry. The homology between T. trichiura and the related nematode Trichinella spiralis was used to identify 12 proteins in TtEFs. Among those identified, fructose biphosphate aldolase, a homologue of macrophage migration inhibitory factor and heat-shock protein 70 may contribute to the immunomodulatory effects of TtEFs. The identification of such proteins could lead to the development of novel drugs for the therapy of allergic and other inflammatory diseases.

Oocyst ingestion as an important transmission route of Toxoplasma gondii in Brazilian urban children.

Toxoplasmosis is a cosmopolitan protozoan infection. Data regarding risk factors for the post-natal acquisition of Toxoplasma gondii infection in childhood are limited. We conducted a serological survey for T. gondii IgG antibodies and associated risk factors in 1,217 children 4-11-yr-old from Salvador, Brazil, using a commercial ELISA kit; antibodies were found in 17.5% of the children. Age (OR  =  2.18; 95% CI: 1.50-3.17) and maternal schooling level (OR  =  0.62; 95% CI: 0.42-0.92) were negatively associated with infection. A greater number of siblings (OR  =  1.53; 95% CI: 1.12-2.09), cat at home (OR  =  1.54; 95% CI: 1.06-2.24), house with non-treated piped water (OR  =  2.54; 95% CI: 1.22-5.31), and the absence of a flush toilet at home (OR  =  1.45; 95% CI: 1.04-2.01) were positively associated with T. gondii infection. Our data suggest that low socioeconomic levels and poor hygiene habits are important factors in favoring T. gondii infection.

Toxocara canis infection is associated with eosinophilia and total IgE in blood donors from a large Brazilian centre.

OBJECTIVE: To investigate the association between Toxocara canis infection and total IgE levels and eosinophilia in blood donors from a large Brazilian city. METHODS: Two hundred and sixty-eight blood donors from a government blood bank were tested. No helminth infection was diagnosed by parasitological stool examination. Total IgE levels and T. canis infection status were determined by ELISA. Eosinophil levels were determined using an automatic blood cell counter. RESULTS: Toxocara canis IgG antibodies were found in 124 (46.3%); 102 (38.0%) had eosinophilia ≥4% and 29 (10.8%) had eosinophilia ≥10%, respectively; 140 (52.2%) individuals had total IgE antibodies above the cut-off levels. Both total IgE and eosinophil levels ≥10% were positively associated with the infection. CONCLUSION: This study revealed a high prevalence of T. canis infection in blood donors, highlighting the need for screening for this infection. It also demonstrated that this population otherwise healthy has higher levels of blood eosinophils and total IgE and that both parameters are associated with T. canis infection.

Anti-allergic effect of bee pollen phenolic extract and myricetin in ovalbumin-sensitized mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The bee pollen is used in folk medicine to alleviate allergic reactions. The bee pollen phenolic extract (BPPE) consists in phenolic compounds (flavonoids) from plants picked by Apis mellifera bee. AIM OF THIS STUDY: Here we evaluated the anti-allergic property of the BPPE and the flavonoid myricetin (MYR) in murine model of ovalbumin (OVA)-induced allergy. MATERIALS AND METHODS: The study focused on the BPPE or myricetin treatment of OVA-sensitized BALB/c mice and their effects on the IgE and IgG1 production, pulmonary cell migration, eosinophil peroxidase (EPO) activity and anaphylactic shock reaction. RESULTS: The BPPE treatment (200mg/kg) showed inhibition of the paw edema, IgE and IgG(1) OVA-specific production, leukocyte migration to the bronchoalveolar lavage (BAL) and EPO activity in lungs. In addition, BPPE treatment showed partial protection on the anaphylactic shock reaction induced by OVA. Treatment with myricetin (5 mg/kg) also inhibited pulmonary cell migration and IgE and IgG(1) OVA-specific production. CONCLUSIONS: These results support the hypothesis the myricetin is one of the flavonoids of BPPE responsible for the anti-allergic effect and a potential tool to treat allergies.

A serological study of Cryptosporidium transmission in a periurban area of a Brazilian Northeastern city.

OBJECTIVES: To study the prevalence of Cryptosporidium infection by measuring the levels of anti-Cryptosporidium IgG antibodies among people inhabiting three neighbourhoods of a periurban area of Salvador, Northeast of Brazil; and to investigate the effects of environmental sanitation measures, hygienic habits and household water supply, storage and handling on the frequency of these antibodies in sera of the studied population. METHODS: Cryptosporidium inter-household transmission was studied by comparing the frequency of anti-Cryptosporidium IgG antibodies among people inhabiting areas with or without different environmental sanitation measures and intra-household transmission by comparing the presence of these antibodies in families with or without cases of diarrhoea, associated with the presence of Cryptosporidium oocysts in their stools. Children or family members with diarrhoeal episodes were evaluated parasitologically for Cryptosporidium infection by testing stool specimens with the Ritchie-modified formol-ether concentration and the acid-fast staining methods. All groups were serologically evaluated for parasite exposure by an indirect enzyme-linked immunosorbent assay. RESULTS: A statistically significant difference was detected in the prevalence of Cryptosporidium infection between area 1 which had no environmental sanitation measures and area 3 which had improved environmental sanitation measures (P = 0.044). Most of the hygienic habits investigated did not correlate with the presence of anti-Cryptosporidium antibody in sera of the population studied. However, positive associations were found between both poor household water supply (OD = 0.17; 90% CI = 0.09-0.32; P = 0.0001) and drinking unboiled/unfiltered water (OD = 0.40; 90% CI = 0.24-0.67; P = 0.0002) with high levels of anti-Cryptosporidium antibodies in sera. CONCLUSIONS: These data suggest that although uncorrected household water supply, storage and handling play an important role on Cryptosporidium transmission in periurban areas of developing country cities, like Salvador, Brazil, inadequate environmental conditions may also contribute to the spread of this parasite.

Análise da confiabilidade de um método de mensuração do ângulo de pico de torque ativo dos isquiossurais / Analysis of the reliability of a method for measuring hamstring active peak torque angle

INTRODUÇÃO: O comprimento muscular pode ser inferido através da determinação da relação comprimento-tensão do músculo. Essa relação é tradicionalmente investigada por meio da medida do torque máximo produzido pelo músculo e do ângulo em que esse torque é gerado. OBJETIVO: O presente estudo verificou a confiabilidade teste-reteste de um método de mensuração do ângulo de pico de torque ativo dos isquiossurais em jovens saudáveis. MÉTODO: Vinte e cinco indivíduos saudáveis (22,88 ± 1,67 anos) foram avaliados duas vezes em um intervalo de três semanas. Um dinamômetro isocinético foi utilizado no modo passivo para avaliar o torque passivo dos isquiossurais. A atividade muscular foi monitorada para garantir silêncio eletromio-gráfico. O dinamômetro foi utilizado no modo concêntrico para determinar o torque total dos isquiossurais. O torque ativo foi obtido subtraindo-se o torque passivo do torque total. O ângulo do pico de torque ativo foi utilizado para a análise. RESULTADO: Não houve diferença estatisticamente significativa entre as duas medidas realizadas (t= 1,009; p= 0,323). O Coeficiente de Correlação Intraclasse para os valores obtidos do ângulo de pico de torque ativo foi de 0,948 (p= 0,0001; IC 95 por cento 0,881 - 0,977). CONCLUSÃO: O presente estudo demonstrou que o método descrito é confiável para a quantificação deste ângulo, sugerindo que este método pode ser utilizado para avaliar mudanças da curva torque-ângulo promovidas por alterações de comprimento muscular.

INTRODUCTION: Muscle length can be inferred from the length-tension relationship of the muscle. This relationship is traditionally investigated by measuring the peak torque produced by the muscle and the angle at which it is generated. OBJECTIVE: The present study investigated the test-retest reliability of a method for measuring hamstring active peak torque angle in healthy young adults. METHOD: Twenty-five healthy individuals (22.88 ± 1.67 years) were assessed twice with an interval of three weeks. An isokinetic dynamometer was used in passive mode to assess hamstring passive torque. Muscle activity was monitored to ensure electromyographic silence. The dynamometer was also used in concentric mode to determine hamstring total torque. The active torque was obtained as the difference between total torque and passive torque. The active peak torque angle was used for the analysis. RESULTS: There was no significant difference between the two measurements (t= 1.009; p= 0.323). The intraclass correlation coefficient for the active peak torque angle values obtained was 0.948 (p= 0.0001; 95 percent CI: 0.883 - 0.977). CONCLUSION: This study has shown that the method described is reliable for the quantification of active peak torque angle, thus suggesting that this method can be used to evaluate shifts in the torque-angle curve produced by muscle length changes.

Incomplete dominance of the low antibody response to Cryptosporidium parvum antigens in mice selected for high and low antibody responsiveness.

The humoral antibody response to Cryptosporidium was investigated in mice genetically selected for high (H) and low (L) antibody responsiveness. Groups of 4-5 mice from two different selections, general primary (GP) and general secondary (GS), were studied. Following immunization with Cryptosporidium parvum antigens, the maximum levels of IgG in the HGP (X +/- SD = 1.13 +/- 0.35, N = 5) in the HGS (0.42 +/- 0.15, N = 4) lines, and of IgM in the HGP line (0.86 +/- 0.53, N = 5) were significantly higher than those in their L counterparts (0.04 +/- 0.02, N = 5; 0.05 +/- 0.02, N = 4 and 0.24 +/- 0.07, N = 5, respectively). These findings were similar to those reported for other immunogens. However, the IgG (0.22 +/- 0.05, N = 4) and the IgM (0.33 +/- 0.08, N = 4) responses to immunization of F1 (LGP x HGP) hybrids indicated an incomplete dominance of the low response, in contrast to the incomplete dominance of the high response described for many other antigens and representing an important exception. In addition, the H, L and F1 mice did not develop detectable infections when inoculated with live Cryptosporidium oocysts, supporting the view that a reduced or zero antibody production itself is not enough to permit the establishment of Cryptosporidium infection in adult mice.

Incomplete dominance of the low antibody response to Cryptosporidium parvum antigens in mice selected for high and low antibody responsiveness

The humoral antibody response to Cryptosporidium was investigated in mice genetically selected for high (H) and low (L) antibody responsiveness. Groups of 4-5 mice from two different selections, general primary (GP) and general secondary (GS), were studied. Following immunization with Cryptosporidium parvum antigens, the maximum levels of IgG in the HGP, (X ñ SD = 1.13 ñ 0.35, N = 5) and in the HGS (0.42 ñ 0.15, N = 4) lines, and of IgM in the HGP line (0.86 ñ 0.53, N = 5) were significantly higher than those in their L counterparts (0.04 ñ 0.02, N = 5;0.05 ñ 0.02, N = 4 and 0.24 ñ 0.07, N = 5, respectively). These findings were similar to those reported for other immunogens. However, the IgG (0.22 ñ 0.05, N = 4) and the IgM (0.33 ñ 0.08, N = 4) responses to immunization of F1 (LGP x HGP) hybrids indicated an incomplete dominance of the low response, in contrast to the incomplete dominance of the high response described for many other antigens and representing an important exception. In addition, the H, L and F1 mice did not develop detectable infections when inoculated with live Cryptosporidium oocysts, supporting the view that a reduced or zero antibody production itself is not enough to permit the establishment of Cryptosporidium infection in adult mice.

Circulating trans-sialidase activity and trans-sialidase-inhibiting antibodies in Trypanosoma cruzi-infected mice.

Parasite-derived trans-sialidase (TS) activity was demonstrated in the serum and blood of Trypanosoma cruzi-infected mice. Serum TS activity levels correlated well with parasitemia in BALB/c and Swiss mice during the initial stages of the infection. However, in later stages the TS activity levels decreased despite increasing parasitemia. This coincided with the appearance of circulating TS antibodies. On the other hand, there was always a good correlation between TS activity and parasitemia in athymic nude mice. Sera from mice with high parasitemia and low TS activity inhibited TS activity in vitro. The inhibition was also observed with purified serum IgG, and it was absorbed by staphylococcal protein A, indicating that it was caused by anti-TS IgG antibodies. These antibodies inhibited the enzymatic activity of insolubilized TS, indicating that they act by interfering with the catalytic site rather than by aggregating the enzyme. The presence of inhibitory antibodies, however, did not prevent the progression of parasitemia in BALB/c mice.

Induction and modulation of the immune response to Leishmania by Montenegro's skin test.

The intradermal inoculation in naive or in previously sensitized individuals of small amounts of Leishmania extract (Montenegro's skin test) induced or modulated, respectively, the immune response to Leishmania, as assessed by subsequent Montenegro's skin tests. These phenomena could hinder the interpretation of Montenegro's skin tests in a population already subjected to the test in the past and, in addition, could affect in an unknown way the development of mucosal lesions in people infected with L. braziliensis or L. amazonensis, since those lesions have been associated with hypersensitivity to Leishmania antigens. Anti-Leishmania antibody responses, assessed by enzyme-linked immunosorbent assay, were not induced in naive individuals by Montenegro's skin tests, but tended to become more intense following these tests in previously sensitized individuals.

Epidemiological aspects of toxoplasmosis in schoolchildren residing in localities with urban or rural characteristics within the city of Rio de Janeiro, Brazil.

Immunofluorescence tests (IF) for toxoplasmosis were performed on a total of 608 schoolchildren in elementary and junior high grades. 166 being in the Bonsucesso district (an urban region of Rio de Janeiro) and 442 children from locations within the lowlands of Jacarepaguá (with rural characteristics). All the IF-IgM were nonreactive, whilst 416 schoolchildren (68.4%) were IF-IgG serum-reactive (greater than or equal to 1:16). The percentages of serum-reactives in Jacarepaguá were significantly higher than in Bonsucesso, both as regards the total number of schoolchildren (p less than 0.001), as also when subdivided according to the age-grades from six to eight years (p less than 0.001) or from twelve to fourteen (p less than 0.05). Both in Jacarepaguá and in Bonsucesso, the prevalence of reactions in the 12 to 14 year age-grade was significantly greater than in the 6 to 8 year age-grade (p less than 0.001 in both cases). Expressively larger prevalences of serum reactions were found in Jacarepaguá among schoolchildren who preferred eating raw or undercooked meat, as well as among those having cats as pets; this occurred equally in the 6 to 8 year and in the 12 to 14 year age-grades. In Bonsucesso, the only significant difference was in the 6 to 8 year age-grades that had cats as pets. Thus, it has been verified that the risk of infection is greater and more precocious in localities with rural characteristics than in urban regions.