Evaluation of the immune response to CRA and FRA recombinant antigens of Trypanosoma cruzi in C57BL/6 mice

Humoral and cellular immune responses were evaluated in 44 C57BL/6 mice immunized with the Trypanosoma cruzi recombinant antigens CRA and FRA. Both antigens induced cutaneous immediate-type hypersensitivity response. The levels of IgG1, IgG2a, IgG2b and IgG3 were high in CRA immunized mice. IgG3 was the predominant isotype. Although no difference in antibody levels was observed in FRA-immunized mice when compared to control mice, both antigens were able to induce lymphoproliferation in immunized mice. Significant differences were observed between incorporation of [³H]- thymidine by spleen cell stimulated in vitro with CRA or FRA and the control group. These results suggest that CRA and FRA could be involved in mechanisms of resistance to Trypanosoma cruzi infection.

Prolonged survival and immune reconstitution after chagasic meningoencephalitis in a patient with acquired immunodeficiency syndrome

We report a case of cerebral meningoencephalitis due to Trypanosoma cruzi in a patient with acquired immunodeficiency syndrome. The patient presented with seizures and focal neurological signs. Definitive diagnosis of chagasic meningoencephalitis was made by demonstration of free trypomastigote forms in the cerebrospinal fluid. Benznidazol was prescribed with clinical and neurological improvement. Antiretroviral drugs improved cellular immunity and three years later the patient presents a good clinical condition with immune reconstitution and undetectable viral load. Chagasic meningoencephalitis has a poor prognosis when specific treatment is not initiated or is delayed. A high index of diagnosis is necessary for early diagnosis and treatment, especially in endemic areas for Trypanosoma cruzi infection.

Oral cavity lymphoma as secondary AIDS-defining neoplasm in a patient on HAART with immune reconstitution

Lymphomas of the oral cavity are a rare complication of advanced HIV/AIDS disease. The clinical appearance of these neoplasms includes masses or ulcerative lesions that involve the oral soft tissue and the jaw as the predominant manifestation. We report the case of a patient with AIDS who developed diffuse large B-cell non-Hodgkin’s lymphoma of the oral cavity during highly active antiretroviral therapy, with undetectable plasma viral load and immune reconstitution.

Humoral immune response of patients bitten by the snake Bothrops erythromelas

INTRODUCTION: Snake envenomings are a health problem in rural areas of tropical and subtropical countries, but little is known regarding the immune response presented by bitten individuals. The IgM production of patients bitten by Bothrops erythromelas snake was analyzed to identify the effectiveness of treatment in this type of envenomation. METHODS: Bothrops erythromelas venom was submitted to electrophoresis and transferred to a nitrocellulose sheet, following incubation with patients' sera. RESULTS: A 38 KDa protein was detected before and 24 h after therapy. CONCLUSIONS: The result suggests that this protein could be used as a marker for individuals envenomed by Bothrops. erythromelas.

Evaluation of drought tolerance in several genotypes of spelt (Triticum aestivum Var. Spelta)

Domestication of plants and plant breeding have dramatically eroded the allelic variations of crop species which led to an increasing susceptibility of crop plants to environmental stresses, diseases and pests. Drought is a major environmental stress factor that affects the growth and development of plants so the selection of tolerant genotypes becomes increasingly important with respect to the predicted effects of global warming. In this study, several genotypes of Spelt (Triticum aestivum var. spelta) were tested under low water supply in soil with the aim of to find Spelt genotypes more resistant than wheat to these conditions, and select them so that in future may be used to improve wheat crops. Morphological analyses were performed and mineral and enzymatic analyses and also dry matter production were calculated. Our results suggests that the genotypes Sp53, Sp96, Sp912, Sp757 and Sp804 are a potential ones to use in breeding programs to improve wheat production. Under drought, these genotypes had growth efficiency of 38%, 45%, 64%, 37%, and 31% respectively and also showed higher biomass than modern wheat and were also mineralogical richer. The genotypes Sp96 and Sp912 showed highest activity of all antioxidants enzymes tested. This work proves that Spelt is a good wheat to continue to study in order to improve wheat crops in dry areas and consequently increase the quality of life and health of the populations living in those areas.

Study of salt stress tolerance in spelt

World population is increasing at an alarming rate while food productivity is decreasing due to the effect of various abiotic stresses. Soil salinity is one of the most important abiotic stress and a limiting factor for worldwide plant production. In addition to its important effects on yield, salt stress affects numerous cellular activities, including cell wall composition, photosynthesis, protein synthesis, ions and organic solutes. Up to 20% of the irrigated arable land in arid and semiarid regions is already salt affected and is still expanding. Improving salt tolerant varieties is of major importance, and efforts should be focused on finding adaptive mechanisms which are involved in salinity tolerance. In this study, several spelt wheat (Triticum aestivum var. Spelta) genotypes and one cultivar of modern bread wheat were used to screen them for salt tolerance. Spelt is an old-European cereal crop currently attracting renewed interest as a food grain because it is said to be harder than wheat and requires less fertilizer. Spelt wheat is also becoming very attractive genetic source by plant breeders due to its wide adaptation ability to various stressful conditions such as soil salinity. In this study morphological parameters (e.g., leaf appearance; shoot elongation), dry matter production, mineral nutrients (especially Na and K), and activity of antioxidative enzymes were measured to select superior genotypes of spelt for salt tolerance. The results showed that Spelt genotype Sp41 is a salt sensitive genotype and genotypes Sp69, Sp96 and Sp912 are good candidates for salt tolerant genotypes.

Involvement and interactions of different immune cells and their cytokines in human visceral leishmaniasis

Visceral leishmaniasis (VL) or kala-azar, a disseminated infection of the lymphoreticular system of the body, is marked by severe defect in immune system of the host. Successful cure of VL depends on the immune status of the host in combination with the effects of the antileishmanial drugs. The rationale approach towards eradication of this disease would be to potentiate the immune functioning of the host in addition to parasite killing. This review deals with different aspects of adaptive and innate immune responses and explores their role in protection or pathogenesis of VL. IL-10 has emerged as the principal cytokine responsible for disease pathogenesis, although evidences regarding its source during active VL remain inconclusive. On the other hand, IFNγ, under the influence of IL-12, is mostly correlated with healing of the disease. Chemokines are important in mounting cell-mediated immune response as they can prevent parasite invasion in association with cytokines. Different types of T cells like CD4, CD8 and NK T cells also contribute to the immunology of this disease. In spite of conflicting reports, the role of regulatory T cells in VL pathogenesis is important. Recently discovered Th17 subset and its different members have been reported to perform diverse functions in the course of VL and leishmaniasis as a whole. Innate immune responses, depending on the cell types, are essential in early parasite detection and subsequent development of an efficient NK cell response. Immunotherapy targeting IL-10 could be looked upon as an interesting option for the treatment of VL.

Puerperal brain cryptococcoma in an HIV-negative woman successfully treated with fluconazole: a case report

Cryptococcus spp. cerebral abscesses are uncommon in immunocompetent subjects. The recommended induction treatment is the administration of amphotericin B plus flucytosine combined with resection for lesions ≥3cm. In this paper, we describe an HIV-negative woman diagnosed with a large cryptococcoma in the immediate postpartum period. The lesion was not resected, and due to amphotericin B intolerance, she received an extended course of fluconazole monotherapy. There was no disease recurrence during the 4 years of follow-up. The abrupt onset of her symptoms following delivery suggests that she developed a postpartum immune reconstitution syndrome. This case also demonstrates that in specific situations fluconazole monotherapy can be attempted in immunocompetent patients with cryptococcoma.

Immune reconstitution inflammatory syndrome in HIV and sporotrichosis coinfection: report of two cases and review of the literature

We report 2 cases of patients with immune reconstitution inflammatory syndrome (IRIS) associated with cutaneous disseminated sporotrichosis and human immunodeficiency virus (HIV) coinfection. The patients received specific treatment for sporotrichosis. However, after 4 and 5 weeks from the beginning of antiretroviral therapy, both patients experienced clinical exacerbation of skin lesions despite increased T CD4+ cells (T cells cluster of differentiation 4 positive) count and decreased viral load. Despite this exacerbation, subsequent mycological examination after systemic corticosteroid administration did not reveal fungal growth. Accordingly, they were diagnosed with IRIS. However, the sudden withdrawal of the corticosteroids resulted in the recurrence of IRIS symptoms. No serious adverse effects could be attributed to prednisone. We recommend corticosteroid treatment for mild-to-moderate cases of IRIS in sporotrichosis and HIV coinfection with close follow-up.

Induction and nosocomial dissemination of carbapenem and polymyxin-resistant Klebsiella pneumoniae

INTRODUCTION:Polymyxins are antimicrobial agents capable of controlling carbapenemase-producing Klebsiella pneumoniae infection.METHODS: We report a cluster of four patients colonized or infected by polymyxin-resistant and Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae.RESULTS: Three patients were hospitalized in adjacent wards, and two were admitted to the intensive care unit. The index case maintained prolonged intestinal colonization by KPC-producing K. pneumoniae. Three patients received polymyxin B before the isolation of polymyxin-resistant K. pneumoniae.CONCLUSIONS: Colonization by KPC-producing K. pneumoniae and previous use of polymyxin B may be causally related to the development of polymyxin-resistant microorganisms.

Understanding how dentritic cell glycans affect antitumor immune responses

RESUMO: As células dendríticas (DCs) têm a capacidade única de induzir respostas imunitárias contra as células tumorais, fagocitando antigénios tumorais e apresentando-os às células T, provocando respostas imunitárias específicas que conduzem à eliminação de células de tumorais. Por induzirem memória imunológica de longa duração, as DCs são uma estratégia atrativa para o tratamento e/ou prevenção do cancro. No entanto, os resultados terapêuticos obtidos em ensaios clínicos com DCs são escassos e pouco eficientes. O nosso grupo demonstrou que ácidos siálicos que contêm glicanos desempenham um papel funcional importante em DCs geradas ex vivo. Com o objetivo de estabelecer um modelo in vitro para avaliar a resposta anti-tumoral específica realizou-se um tratamento enzimático a DCs derivadas de monócitos (moDCs) com sialidase, enzima que cliva ácidos siálicos na superfície celular. O perfil de maturação de moDCs foi caracterizado por citometria de fluxo e expressão de citocinas. Os resultados mostram que a sialidase pode regular positivamente a expressão de moléculas co-estimuladoras na superfície de moDCs estimuladas com agonistas de Toll like receptors (TLRs). Para percebermos se o tratamento com sialidase afeta a sinalização dos TLRs foram usadas células HEK transfectadas de forma estável com TLRs 2, 4 and 7/8. Os dados mostraram que a desialilação não afeta a sinalização através estes recetores. Para investigar o impacto funcional da sialidase na capacidade de moDCs em apresentar um antigénio e ativar células T, moDCs foram tratadas, ou não, com sialidase e cultivadas com clones de células T CD8+ específicas para os péptidos derivados do antigénio tumoral gp100. Os resultados mostram que DCs HLA*02:01+ desialiladas exibem maior cross-presentation do péptido gp100280-288 às células T CD8+ específicas. Além disso o tratamento com sialidase também aumenta a capacidade de DCs de induzir a proliferação de células T CD4+. Em conjunto, os resultados indicam que moDCs com menos ácidos siálicos na superfície, têm melhor potencial imuno-estimulador, com maior capacidade de induzir respostas imunes anti-tumorais.--------------------- ABSTRACT: Dendritic cells (DCs) have a unique capacity to induce immune responses against tumor cells. They can phagocyte tumor antigens, maturate and present them to T cells, triggering antigen-specific immune responses that may lead to the elimination of tumor cells. Since they induce long-lasting immunological memory, DCs become an attractive strategy as cellular targets for vaccines in the treatment and/or prevention of cancer. However, the therapeutic results obtained in clinical trials with DCs are scarce and only few patients effectively respond to the DC vaccines. Our group has shown that sialic acid containing glycans play an important functional role in ex vivo generated DC. Here we aimed to establish an in vitro model to assess specific antitumor responses. To achieve this, an enzymatic treatment of monocyte-derived DCs (moDCs) was performed using sialidase to cleave surface sialic acids. The maturation profile of the moDCs was characterized by flow cytometry and cytokine expression. The results show that sialidase treatment can upregulate co-stimulatory molecules on surface of moDCs stimulated with Toll like receptor (TLR) agonists. To understand whether sialidase treatment affected the TLR signaling, we have used HEK cells stably transfected with TLRs 2, 4 and 7/8. The data showed that desialylation of moDCs does not affect the signaling via these receptors. To investigate the functional impact of sialidase treatment in the capacity of moDCs to present antigen and to activate antigen specific T cells, sialidase treated and untreated moDCs were co-cultured with CD8+ T cell clones specific for peptides derived from the gp100 tumor antigen. Our results show that desialylated HLA02:01+ DCs are superior in cross-presentation of the peptide to gp100280–288 specific CD8+ T cells. In addition, sialidase treatment also increased the DC capacity to induce CD4+ T cells proliferation. Together, these data indicate that moDCs with altered cell surface sialic acids, through a sialidase treatment, have a better immunostimulatory potential which could improve anti-tumor immune responses.

Comparison of the fluorescent polarization (TDx) and the enzymatic competitive (EMIT 2000) immune assays for the measurement of cyclosporin A blood concentration

Evaluation of Cyclosporin A (CyA) blood concentration is imperative in solid organ transplantation in order to achieve maximal immunosuppression with the least side effects. We compared the results of whole blood concentrations of CyA in 50 blood samples simultaneously evaluated by the fluorescent polarization immune assay (TDx) and the enzymatic competitive immune assay (EMIT 2000). There was a strong correlation between both kits for any range of CyA blood concentration (R=0.99, p<0.001). The within-run and between-days coefficient of variation were less than 4% for both assays. The cost for each CyA measurement was 50% lower for the EMIT assay when compared to the TDx assay. We concluded that the EMIT is as accurate as the TDx in measuring CyA blood concentration and has the advantage of a lower cost, as well as the possibility of widespread access to the EMIT methodology in contrast to the TDx equipment, allowing the laboratory to perform several routines within a working day.

Machine diagnosis based on artificial immune systems

Nowadays, many of the manufactory and industrial system has a diagnosis system on top of it, responsible for ensuring the lifetime of the system itself. It achieves this by performing both diagnosis and error recovery procedures in real production time, on each of the individual parts of the system. There are many paradigms currently being used for diagnosis. However, they still fail to answer all the requirements imposed by the enterprises making it necessary for a different approach to take place. This happens mostly on the error recovery paradigms since the great diversity that is nowadays present in the industrial environment makes it highly unlikely for every single error to be fixed under a real time, no production stop, perspective. This work proposes a still relatively unknown paradigm to manufactory. The Artificial Immune Systems (AIS), which relies on bio-inspired algorithms, comes as a valid alternative to the ones currently being used. The proposed work is a multi-agent architecture that establishes the Artificial Immune Systems, based on bio-inspired algorithms. The main goal of this architecture is to solve for a resolution to the error currently detected by the system. The proposed architecture was tested using two different simulation environment, each meant to prove different points of views, using different tests. These tests will determine if, as the research suggests, this paradigm is a promising alternative for the industrial environment. It will also define what should be done to improve the current architecture and if it should be applied in a decentralised system.

Induction of experimental mammary carcinogenesis in rats with 7,12-dimethylbenz(a)anthracene

PURPOSE: To test an experimental model of chemical mammary carcinogenesis induction in rats. METHODS: Twenty young virgin Sprague-Dawley female rats, aged 47 days, received 20 mg of 7,12-dimethylbenz(a)anthracene (DMBA) intragastrically by gavage. Afterwards, at 8 and 13 weeks, their mammary glands were examined. At the end of the experiment, the animals were sacrificed, and the mammary tumors were measured and weighed. Tumor fragments were analyzed using light microscopy. RESULTS: Eight weeks after DMBA injection, 16 rats presented at least 1 breast tumor (80%). After 13 weeks, all of them (100%) developed breast carcinomas that were confirmed by histopathological analysis. CONCLUSION: This experimental animal model of chemical mammary induced carcinogenesis is feasible and can be used in further experiments on the role of tumorigenic biomodulator substances.

Candida bracarensis: Evaluation of virulence factors and its tolerance to Amphotericin B and Fluconazole

Candida bracarensis is an uncommon Candida species found during an epidemiological study of candidiasis performed in Braga, Portugal. Initially, it was identified as C. glabrata, but recently detailed analyses pointed out their differences. So, little information is still available about C. bracarensis virulence factors and antifungal susceptibilities. Therefore, the main goal of this work is to evaluate the ability of C. bracarensis to form biofilms, to produce hydrolytic enzymes (proteases, phospholipases and hemolysins), as well as its susceptibility to amphotericin B and fluconazole. It was shown, for the first time, that all C. bracarensis strains were able to form biofilms and display proteinase and hemolytic activities. Moreover, although planktonic cells presented antifungal susceptibility, amphotericin B and fluconazole were unable to inhibit biofilm formation and eradicate pre-formed biofilms. Due to the propensity of C. bracarensis to display antifungal resistance and virulence attributes, the control of these emerging pathogens is recommended.