Regulatory Cells, Cytokine Pattern and Clinical Risk Factors for Asthma in Infants and Young Children with Recurrent Wheeze

Several risk factors for asthma have been identified in infants and young children with recurrent wheeze. However, published literature has reported contradictory findings regarding the underlying immunological mechanisms. OBJECTIVES: This study was designed to assess and compare the immunological status during the first 2 years in steroid-naive young children with >or= three episodes of physician-confirmed wheeze (n=50), with and without clinical risk factors for developing subsequent asthma (i.e. parental asthma or a personal history of eczema and/or two of the following: wheezing without colds, a personal history of allergic rhinitis and peripheral blood eosinophilia >4%), with age-matched healthy controls (n=30). METHODS: Peripheral blood CD4(+)CD25(+) and CD4(+)CD25(high) T cells and their cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), GITR and Foxp3 expression were analysed by flow cytometry. Cytokine (IFN-gamma, TGF-beta and IL-10), CTLA-4 and Foxp3 mRNA expression were evaluated (real-time PCR) after peripheral blood mononuclear cell stimulation with phorbol 12-myristate 13-acetate (PMA) (24 h) and house dust mite (HDM) extracts (7th day). RESULTS: Flow cytometry results showed a significant reduction in the absolute number of CD4(+)CD25(high) and the absolute and percentage numbers of CD4(+)CD25(+)CTLA-4(+) in wheezy children compared with healthy controls. Wheezy children at a high risk of developing asthma had a significantly lower absolute number of CD4(+)CD25(+) (P=0.01) and CD4(+)CD25(high) (P=0.04), compared with those at a low risk. After PMA stimulation, CTLA-4 (P=0.03) and Foxp3 (P=0.02) expression was diminished in wheezy children compared with the healthy children. After HDM stimulation, CTLA-4 (P=0.03) and IFN-gamma (P=0.04) expression was diminished in wheezy children compared with healthy children. High-risk children had lower expression of IFN-gamma (P=0.03) compared with low-risk and healthy children and lower expression of CTLA-4 (P=0.01) compared with healthy children. CONCLUSIONS: Although our findings suggest that some immunological parameters are impaired in children with recurrent wheeze, particularly with a high risk for asthma, further studies are needed in order to assess their potential as surrogate predictor factors for asthma in early life.

Study and characterization of the ZnPc:C60/MoOx interface in organic solar cells by means of photoelectron spectroscopy

Dissertation to obtain the academic degree of Master in materials engineering submitted to the Faculty of science and engineering of Universidade Nova de Lisboa

The influence of CD 4+t cells, hiv disease stage and zidovudine on hiv isolation in Bahia, Brazil

HIV-l isolation was attempted on 72 individuais, including persons with knoum HIV infection and five without proven HIV infection but with indeterminate Western blot patterns, as well as on low-risk HIV seronegative persons. The ahility to detect HIV- 1 frorn culture supernatant by p24 antigen capture assay was evaluated by segregating patients by absolute CD4+ cell counts, clinicai stage of disease, p24 antigenemia and zidovudine use. The likelihood of a p24 positive HIV culture was highest among patients with CD4+ T-cell counts below 200/ul and patients with advanced clinical disease. Use of zidovudine did not affect the rate ofHIV positwity in cultures.

Overexpressing BDNF in Neural Stem Cells using non-viral gene delivery strategies

Dissertação para obtenção do Grau de Mestre em Biotecnologia

Potential of CPV receivers integrating screen-printed solar cells

Dissertação para obtenção do Grau de Mestre em Energias Renováveis – Conversão Eléctrica e Utilização Sustentável

Bioprocess engineering of induced pluripotent stem cells for application in cell therapy and pre-clinical research

Dissertation to obtain Master Degree in Biotechnology

Establishment of HTLV-I-infected cell lines from peripheral blood mononuclear cells of Brazilian patients

To investigate epidemiological and pathogenetic features of HTLV-I infection, a cohort of carriers has been followed at the USP Teaching Hospital since 1991. This study describes the establishment of cell lines from peripheral blood mononuclear cells (PBMC) of infected subjects. Ex vivo PBMC were cultured with those from a seronegative donor and morphologic evidence of cell transformation was obtained after 90 days with detection of multinucleated cells exhibiting cerebriform nuclei. Integration of HTLV-I proviral DNA and expression of viral antigens was demonstrated in culture by PCR and immunofluorescence. Cell lines were maintained for 240 days, gradually weaned from exogenous IL-2. Immunophenotyping of cell lines on flow cytometry yielded evidence of cell activation. Establishment of HTLV-I-infected cell lines from ex vivo PBMC is feasible and may be useful for studies on lymphocyte phenotypic changes and on mechanisms of HTLV-induced cell proliferation. Moreover they may be used with diagnostic purposes in immunofluorescence tests.

Cues for cancer stem cells origin

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

Role of Notch signaling on the differentiation of early lymphoid progenitors cells: a view throughout the development of the embryonic chicken thymus and spleen

Dissertação para a obtenção do grau de Mestre em Genética Molecular e Biomedicina

Design of a tool to study the fate of Chlamydia trachomatis infected cells

Chlamydia trachomatis has a unique obligate intracellular developmental cycle that ends by the lysis of the cell and/or the extrusion of the bacteria in order to allow for re-infections. While Chlamydia trachomatis infections are often asymptomatic the diagnosis of Chlamydia trachomatis is usually late, occurring after manifestation of persistency. Investigations on the consequences of long-term infections and the molecular mechanisms behind it will reveal light to what extent bacteria can modulate host cell function and what the ultimate fate of host cells after clearance of an infection is. Such studies on the host cell fate could be greatly facilitated if the infected cells become permanently marked during and after the infection. Therefore, this project intends to develop a new genetic tool that would allow permanently labeling of Chlamydia trachomatis host cells. The plan was to generate a Chlamydia trachomatis strain that encodes a recombinant CRE recombinase, fused to a secretory effector function of the Chlamydia type 3 secretion system (T3SS). Upon translocation into the host cell, this recombinant CRE enzyme could then, owing to its site-specific recombination function, switch a reporter gene contained in the host cell genome. To this end, the reporter line carried a membrane-tagged tdTomato (mT) gene flanked by two LoxP sequences followed by a GFP gene. The translocation of the recombinant CRE recombinase into this cell line was designed to trigger the recombination of the LoxP sites whereby the cells would turn from red fluorescence to green as an irreversible label of the infected cells. Successful execution of this mechanism would allow to draw a direct link between Chlamydia trachomatis infection and the subsequent fate of the infected cell.

Kinetics of IFN-gamma, TNF-alpha, IL-10 and IL-4 production by mononuclear cells stimulated with gp43 peptides, in patients cured of paracoccidioidomycosis

We analyzed the kinetics of cytokine production by mononuclear cells from 17 patients who had been treated for paracoccidioidomycosis, using the stimulus of gp43 peptide groups (43kDa glycoprotein of Paracoccidioides brasiliensis) at 0.1 and 1µM, gp43 (1µg/ml) and crude Paracoccidioides brasiliensis antigen (PbAg; 75µg/ml). IFN-gamma production was a maximum at 144 hours in relation to the G2 and G8 peptide groups at 1µM and was greatest at 144 hours when stimulated by gp43 and by PbAg. The maximum TNF-alpha production was at 144 hours for the G2 group (0.1µM) and for gp43. IL-10 production was highest after 48 and 72 hours for G7 and G6 at 1µM, respectively. We also suggest the best time for analysis of IL4 production. These results may contribute towards future studies with gp43 peptides and encourage further investigations with the aim of understanding the influence of these peptides on the production of inflammatory and regulatory cytokines.

Paracoccidioidomycosis: no genetic damage in human peripheral blood cells of patients assessed by single-cell gel (comet) assay

Paracoccidioidomycosis is a systemic fungal infection caused by Paracoccidioides brasiliensis. As infectious diseases can cause DNA damage, the authors aimed at analyzing DNA breakage in peripheral blood cells of patients with paracoccidioidomycosis by using the comet assay. The results suggested that paracoccidioidomycosis does not cause genotoxicity.

Process Engineering of Stem Cells for Clinical Application

Over the last decade, human embryonic stem cells (hESCs) have garnered a lot of attention owing to their inherent self-renewal ability and pluripotency. These characteristics have opened opportunities for potential stem cell-based regenerative medicines, for development of drug discovery platforms and as unique in vitro models for the study of early human development.(...)

Specific features of endothelial cells in primary tumors

RESUMO: As células endoteliais definem e delineiam todo o sistema vascular...Nesta tese procurámos explorar o papel que o ambiente tumoral exerce sobre as células endoteliais. ... Avaliamos também a capacidade anti-angiogénica de alguns derivados do estrogénio... Em suma os nossos resultados mostram a importância de um controlo rigoroso da regulação transcricional...