Importance of immunoglobulin E (IgE) in the protective mechanism against gastrointestinal nematode infection: looking at the intestinal mucosae

This review discusses experimental evidences that indicate the IgE participation on the effector mechanisms that leads to gastrointestinal nematode elimination. Data discussed here showed that, for most experimental models, the immune response involved in nematode elimination is regulated by Th-2 type cytokines (especially IL-4). However, the mechanism(s) that result in worm elimination is not clear and might be distinct in different nematode species. Parasite specific IgE production, especially the IgE produced by the intestinal mucosae or associated lymphoid organs could participate in the intestinal elimination of Trichinella spiralis from infected rats. Intestinal IgE may also be important to the protective mechanism developed against other gastrointestinal nematodes that penetrate the murine duodenum mucosa tissue, such as Strongyloides venezuelensis and Heligmosomoides polygyrus. At least in Trichinella spiralis infected rats, the results indicated that intestinal IgE might work independently from mast cell degranulation for worm elimination.

Protective effect of C. sativa leaf extract against UV mediated-DNA damage in a human keratinocyte cell line

Toxic effects of ultraviolet (UV) radiation on skin include protein and lipid oxidation, and DNA damage. The latter is known to play a major role in photocarcinogenesis and photoaging. Many plant extracts and natural compounds are emerging as photoprotective agents. Castanea sativa leaf extract is able to scavenge several reactive species that have been associated to UV-induced oxidative stress. The aim of this work was to analyze the protective effect of C. sativa extract (ECS) at different concentrations (0.001, 0.01, 0.05 and 0.1 μg/mL) against the UV mediated-DNA damage in a human keratinocyte cell line (HaCaT). For this purpose, the cytokinesis-block micronucleus assay was used. Elucidation of the protective mechanism was undertaken regarding UV absorption, influence on 1O2 mediated effects or NRF2 activation. ECS presented a concentration-dependent protective effect against UV-mediated DNA damage in HaCaT cells. The maximum protection afforded (66.4%) was achieved with the concentration of 0.1 μg/mL. This effect was found to be related to a direct antioxidant effect (involving 1O2) rather than activation of the endogenous antioxidant response coordinated by NRF2. Electrochemical studies showed that the good antioxidant capacity of the ECS can be ascribed to the presence of a pool of different phenolic antioxidants. No genotoxic or phototoxic effects were observed after incubation of HaCaT cells with ECS (up to 0.1 μg/mL). Taken together these results reinforce the putative application of this plant extract in the prevention/minimization of UV deleterious effects on skin.

Protective and risk factors for toxocariasis in children from two different social classes of Brazil

The aim of this study was to analyze the prevalence of Toxocara spp. antibodies in children from two different socioeconomic classes in the Presidente Prudente municipality, São Paulo State, Brazil, and the protective and risk factors associated with toxocariasis. One hundred and twenty-six middle-class (MC) and 126 disadvantaged children (DC) were included in this study. Anti-Toxocara ELISA test was performed in order to evaluate seroprevalence. A survey was applied to the children's guardians/parents in order to analyze the protective and risk factors. The overall prevalence was 11.1%, and of 9.5% (12/126) and 12.7% (16/126) for MC and DC subgroups, respectively. Toxocara seropositivity was inversely proportional to the family income. A high household income was considered a protective factor for toxocariasis in the total population and in both MC and DC subgroups. Being a girl was considered a protective factor for the total population and for both subgroups. Whilst being an owner of cat was a risk factor for children belonging to the total and for both MC and DC subgroups, having dog was considered as a risk factor for only the MC. Epidemiologic protective/factor risks can be distinct depending on the strata of the same population. Thus, it is relevant to evaluate these factors independently for different socioeconomic classes in order to design future investigations and programs for preventing the infection of human beings by Toxocara spp. and other geohelminths.

PROTECTIVE EFFECT OF THE PROBIOTIC Saccharomyces boulardii IN Toxocara canis INFECTION IS NOT DUE TO DIRECT ACTION ON THE LARVAE

SUMMARY In a previous study our group found that the probiotic Saccharomyces boulardii was capable of reducing the intensity of infection in mice with toxocariasis. In order to assess whether the mechanism involved would be a direct action of the probiotic on Toxocara canis larvae, this study was designed. Both probiotics were singly cultivated in plates containing RPMI 1640 medium and T. canis larvae. S. boulardii and B. cereus var. toyoi cultures presented 97.6% and 95.7% of larvae with positive motility, respectively, and absence of color by the dye trypan blue, not representing significant difference to the control group (p > 0.05). We conclude that none of the probiotics showed in vitro effects on T. canis larvae and that the interaction with the intestinal mucosa is necessary for the development of the protective effect of S. boulardii.

PROTECTIVE LEVELS OF VARICELLA-ZOSTER ANTIBODY DID NOT EFFECTIVELY PREVENT CHICKENPOX IN AN X-LINKED AGAMMAGLOBULINEMIA PATIENT

SUMMARY We describe the case of an eight-year-old boy with X-linked agammaglobulinemia who developed mild varicella despite regular intravenous immunoglobulin (IVIG) therapy. He maintained protective antibody levels against varicella and the previous batches of IVIG that he received had adequate varicella-specific IgG levels. The case illustrates that IVIG may not prevent VZV infection.

A Natural Protective Mechanism Against Malaria

Malaria is an infectious disease of humans and other animals including birds, reptiles and most mammals. It is transmitted via the inoculation of Plasmodium sporozoites into the skin through the bite of an infected female Anopheles mosquito. Although every year, around 700.000 lives are perished, mainly children under the age of 3-5 years old, to Plasmodium infection this deadly parasite has a relatively low efficiency of transmission from mosquitoes into humans.(...)

Protective effect of left ventricular hypertrophy in right coronary artery occlusions

OBJECTIVE: To test the hypothesis that left ventricular hypertrophy (LVH) reduces the electrocardiographic and functional effects of right coronary artery occlusion. METHODS: We analysed 215 patients (166 males and 49 women,age of 58.9±10.6 years), with occlusion of the right coronary artery without other associated lesions. There was no significant difference (p>0.05) in age and gender distribution between the 78 patients with LVH (left ventricular mass >100g/m²) (Group A) when compared with the 137 patients without LVH (left ventricular mass <100g/m²) (Group B). RESULTS: The electrocardiographic finding of transmural necrosis was more often found in group B patients than in group A patients (56.9% and 30.8%, respectively; p<0.05). The left ventricular function parameters of group A were better than those of group B: the ratio end-diastolic pressure/systolic pressure (EDP/SP) (A: 0.108±0.036; B: 0.121±0.050; p<0.05); the end-diastolic volume index (A: 75.9±31.3ml/m²; B: 88.0±31.0ml/m²; p<0.01); the end-systolic volume index (A: 16.0±10.0ml/m²; B: 27.0 ±20.0ml/m²; p<0.001); the ejection fraction (A 78.6±10.8%; B 67.7±17.9%; p<0.001); the anteroinferior shortening (A: 43.9±10.3%; B: 35.1±12.8%; p<0.001). A higher degree of coronary tortuosity was observed in group A than in group B (78.2% and 24.1%; p<0.001) and also a more frequent absent or minimal diaphragmatic hypokinetic area (A: 80.8%; B: 54.0%; p<0.05). CONCLUSION: LVH reduces the effects of myocardial sequela and protects LV function when right coronary occlusion develops.

Protease-activated receptor (PAR)-1 and PAR-2 protect rat astrocytes from apoptotic cell death via differentially regulating JNK isoform-specific release of the chemokine GRO/CINC-1 : two novel protective pathways in brain

Protease-activated receptor; c-Jun N-terminal kinase (JNK); thrombin; neuroprotection; siRNA

Leber's hereditary optic neuropathy (LHON) : involvement of mitochondrial permeability transition in the pathogenesis and protective actions of minocycline

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2008

Protective Effect of Aortic Stenosis on the Coronary Arteries. Hypothetic Considerations to an Old Enigma

Abstract A literature overview of angiographic studies has shown that the prevalence of significant coronary disease in patients with aortic stenosis (AS) varies from 20 to 60%. Early necropsy studies suggested that patients with AS had a lower than expected incidence of coronary artery disease (CAD), originating the concept of a protective effect of AS on the coronary arteries. The myth of AS protection against CAD would be better explained as endothelium-myocardial interaction (crosstalk) protection triggered by left ventricular overload. Therefore, the cGMP/NO pathway induced by the AS overload pressure would explain the low incidence of CAD, which is compatible with the amazing natural long-term evolution of this cardiac valve disease.

Functional studies of β-arresting and αB-crystallin as interaction partners of PAR-1 and PAR-2 and their involvement in protective and proliferative signaling pathways in astrocytes

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2014

Immunogenetic and protective activity of an extract of Schistosoma mansoni

The immunogenic and protective activity of an extract of S. mansoni, obtained by incubation of viable adult worms in buffered saline, was evaluated in rabbits and mice. Animal immunization with this extract resulted in the development of both humoral and cellular immune response. All immunized rabbits developed high levels (91 to 100%) of cytotoxic antibodies as determined by in vitro assays of cytotoxic activity of their sera against viable schistosomules. Immunized animals challenged with S. mansoni cercariae showed a lower parasite load than that of normal controls. Protective activity was 88.6% and 54.0% in immunized rabbits and mice, respectively.

Loss of Cutaneous TSLP-Dependent Immune Responses Skews the Balance of Inflammation from Tumor Protective to Tumor Promoting.

Inflammation can promote or inhibit cancer progression. In this study we have addressed the role of the proinflammatory cytokine thymic stromal lymphopoietin (TSLP) during skin carcinogenesis. Using conditional loss- and gain-of-function mouse models for Notch and Wnt signaling, respectively, we demonstrate that TSLP-mediated inflammation protects against cutaneous carcinogenesis by acting directly on CD4 and CD8 T cells. Genetic ablation of TSLP receptor (TSLPR) perturbs T-cell-mediated protection and results in the accumulation of CD11b(+)Gr1(+) myeloid cells. These promote tumor growth by secreting Wnt ligands and augmenting β-catenin signaling in the neighboring epithelium. Epithelial specific ablation of β-catenin prevents both carcinogenesis and the accumulation of CD11b(+)Gr1(+) myeloid cells, suggesting tumor cells initiate a feed-forward loop that induces protumorigenic inflammation.