Lower serum IgA levels in horses kept under intensive sanitary management and physical training

Quantity and variety of environmental antigens, age, diet, vaccine protocols, exercising practice and mucosal cytokine microenvironment are factors that influence serum immunoglobulin (Ig) levels. IgA, IgG, IgG(T) and IgM were quantified in 60 horses, which were classified into two groups, `intensive` or `relaxed`, according to sanitary standards of the facilities and physical exercise to which animals were subjected to. The `intensive` group presented lower means for all isotypes, but only IgA presented a significant (P < 0.0064) difference when compared to the `relaxed` group. This suggests that mucosal immunity found in the `intensive` group is lower when compared to the `relaxed` group. Our data suggest that athlete horses may be less poised to mount an effective mucosal immunity response to environmental challenges and should not be considered by the same perspectives as a free-ranging horse.

Immobilization of primary cultures of insulin-releasing human pancreatic cells

Transplantation of pancreatic islets isolated from organ donors constitutes a promising alternative treatment for type 1 diabetes, however, it is severely limited by the shortage of organ donors. Ex vivo islet cell cultures appear as an attractive but still elusive approach for curing type 1 diabetes. It has recently been shown that, even in the absence of fibrotic over-growth, several factors, such as insufficient nutrition of the islet core, represent a major barrier for long-term survival of islets grafts. The use of immobilized dispersed cells may contribute to solve this problem due to conceivably easier nutritional and oxygen support to the cells. Therefore, we set out to establish an immobilization method for primary cultures of human pancreatic cells by adsorption onto microcarriers (MCs). Dispersed human islets cells were seeded onto Cytodex1 microcarriers and cultured in bioreactors for up to eight days. The cell number increased and islet cells maintained their insulin secretion levels throughout the time period studied. Moreover, the cells also presented a tendency to cluster upon five days culturing. Therefore, this procedure represents a useful tool for controlled studies on islet cells physiology and, also, for biotechnological applications.

Endocytosis of prion protein is required for ERK1/2 signaling induced by stress-inducible protein 1

The secreted cochaperone STI1 triggers activation of protein kinase A (PKA) and ERK1/2 signaling by interacting with the cellular prion (PrPC) at the cell surface, resulting in neuroprotection and increased neuritogenesis. Here, we investigated whether STI1 triggers PrPC trafficking and tested whether this process controls PrPC-dependent signaling. We found that STI1, but not a STI1 mutant unable to bind PrPC, induced PrPC endocytosis. STI1-induced signaling did not occur in cells devoid of endogenous PrPC; however, heterologous expression of PrPC reconstituted both PKA and ERK1/2 activation. In contrast, a PrPC mutant lacking endocytic activity was unable to promote ERK1/2 activation induced by STI1, whereas it reconstituted PKA activity in the same condition, suggesting a key role of endocytosis in the former process. The activation of ERK1/2 by STI1 was transient and appeared to depend on the interaction of the two proteins at the cell surface or shortly after internalization. Moreover, inhibition of dynamin activity by expression of a dominant-negative mutant caused the accumulation and colocalization of these proteins at the plasma membrane, suggesting that both proteins use a dynamin-dependent internalization pathway. These results show that PrPC endocytosis is a necessary step to modulate STI1-dependent ERK1/2 signaling involved in neuritogenesis.

Metabotropic glutamate receptors transduce signals for neurite outgrowth after binding of the prion protein to laminin gamma 1 chain

The prion protein (PrP(C)) is highly expressed in the nervous system, and its abnormal conformer is associated with prion diseases. PrP(C) is anchored to cell membranes by glycosylphosphatidylinositol, and transmembrane proteins are likely required for PrP(C)-mediated intracellular signaling. Binding of laminin (Ln) to PrP(C) modulates neuronal plasticity and memory. We addressed signaling pathways triggered by PrP(C)-Ln interaction in order to identify transmembrane proteins involved in the transduction of PrP(C)-Ln signals. The Ln gamma 1-chain peptide, which contains the Ln binding site for PrP(C), induced neuritogenesis through activation of phospholipase C (PLC), Ca(2+) mobilization from intracellular stores, and protein kinase C and extracellular signal-regulated kinase (ERK1/2) activation in primary cultures of neurons from wild-type, but not PrP(C)-null mice. Phage display, coimmunoprecipitation, and colocalization experiments showed that group I metabotropic glutamate receptors (mGluR1/5) associate with PrP(C). Expression of either mGluR1 or mGluR5 in HEK293 cells reconstituted the signaling pathways mediated by PrP(C)-Ln gamma 1 peptide interaction. Specific inhibitors of these receptors impaired PrP(C)-Ln gamma 1 peptide-induced signaling and neuritogenesis. These data show that group I mGluRs are involved in the transduction of cellular signals triggered by PrP(C)-Ln, and they support the notion that PrP(C) participates in the assembly of multiprotein complexes with physiological functions on neurons.-Beraldo, F. H., Arantes, C. P., Santos, T. G., Machado, C. F., Roffe, M., Hajj, G. N., Lee, K. S., Magalhaes, A. C., Caetano, F. A., Mancini, G. L., Lopes, M. H., Americo, T. A., Magdesian, M. H., Ferguson, S. S. G., Linden, R., Prado, M. A. M., Martins, V. R. Metabotropic glutamate receptors trans-duce signals for neurite outgrowth after binding of the prion protein to laminin gamma 1 chain. FASEB J. 25, 265-279 (2011). www.fasebj.org

Development of secondary palate requires strict regulation of ECM remodeling: sequential distribution of RECK, MMP-2, MMP-3, and MMP-9

We have evaluated RECK (reversion-inducing-cysteine-rich protein with Kazal motifs), MMP-2 (matrix metalloproteinase-2), MMP-3, and MMP-9 involvement during palate development in mice by using various techniques. Immunohistochemical features revealed the distribution of RECK, MMP-2, and MMP-3 in the mesenchymal tissue and in the midline epithelial seam at embryonic day 13 (E13), MMPs-2, -3, and -9 being particularly expressed at E14 and E14.5. In contrast, RECK was weakly immunostained at these times. Involvement of MMPs was validated by measuring not only their protein expression, but also their activity (zymograms). In situ hybridization signal (ISH) for RECK transcript was distributed in mesenchymal and epithelial regions within palatal shelves at all periods evaluated. Importantly, the results from ISH analysis were in accord with those obtained by real-time polymerase chain reaction. The expression of RECK was found to be temporally regulated, which suggested possible roles in palatal ontogeny. Taken together, our results clearly show that remodeling of the extracellular matrix is finely modulated during secondary palate development and occurs in a sequential manner.

Overexpression of Nrp/b (nuclear restrict protein in brain) suppresses the malignant phenotype in the C6/ST1 glioma cell line

Upon searching for glucocorticoid-regulated cDNA sequences associated with the transformed to normal phenotypic reversion of C6/ST1 rat glioma cells, we identified Nrp/b (nuclear restrict protein in brain) as a novel rat gene. Here we report on the identification and functional characterization of the complete sequence encoding the rat NRP/B protein. The cloned cDNA presented a 1767 nucleotides open-reading frame encoding a 589 aminoacids residues sequence containing a BTB/POZ (broad complex Tramtrack bric-a-brac/Pox virus and zinc finger) domain in its N-terminal region and kelch motifs in its C-terminal region. Sequence analysis indicates that the rat Nrp/b displays a high level of identity with the equivalent gene orthologs from other organisms. Among rat tissues, Nrp/b expression is more pronounced in brain tissue. We show that overexpression of the Nrp/b cDNA in C6/ST1 cells suppresses anchorage independence in vitro and tumorigenicity in vivo, altering their malignant nature towards a more benign phenotype. Therefore, Nrp/b may be postulated as a novel tumor suppressorgene, with possible relevance for glioblastoma therapy. (C) 2009 Elsevier Ltd. All rights reserved.

Prion Protein and Its Ligand Stress Inducible Protein 1 Regulate Astrocyte Development

Prion protein (PrP(C)) interaction with stress inducible protein 1 (STI1) mediates neuronal survival and differentiation. However, the function of PrP(C) in astrocytes has not been approached. In this study, we show that STI1 prevents cell death in wild-type astrocytes in a protein kinase A-dependent manner, whereas PrP(C)-null astrocytes were not affected by STI1 treatment. At embryonic day 17, cultured astrocytes and brain extracts derived from PrP(C)-null mice showed a reduced expression of glial fibrillary acidic protein (GFAP) and increased vimentin and nestin expression when compared with wild-type, suggesting a slower rate of astrocyte maturation in PrP(C)-null animals. Furthermore, PrP(C)-null astrocytes treated with STI1 did not differentiate from a flat to a process-bearing morphology, as did wild-type astrocytes. Remarkably, STI1 inhibited proliferation of both wild-type and PrP(C)-null astrocytes in a protein kinase C-dependent manner. Taken together, our data show that PrP(C) and STI1 are essential to astrocyte development and act through distinct signaling pathways.(C) 2009 Wiley-Liss, Inc.

O saber impotente: estudo da noção de ciência na obra infantil de Monteiro Lobato

A obra infantil de Monteiro Lobato apresenta a ciência de forma diferenciada em três fases. Na primeira, a ciência é inútil e representa um empecilho no desenrolar das aventuras. Na segunda,ela é o próprio motor das histórias. Na terceira, é vista como ferramenta mal utilizada pela civilização. Monteiro Lobato se vinculou a um grupo ontelectual de São Paulo cuja ação está na base da formação do Partido Democritico na década de vinte. A estrutura das fases identificadas na obra infantil corresponde à trajetória política do grupo. Num primeiro momento, ele luta por afirmar-se, por se estabelecer na política regional contra o conservadorismo do PRP. Num segundo momento ele se faz vitorioso, dirigindo o estado; finalmente ele é derrotado pelo golpe de 1937, se desagrega. Seus membros são cooptados ou perseguidos. Assim, a obra infantil de Lobato retrata a saga do liberalismo oligárquico em São Paulo durante a Primeira República.

Alianças eleitorais em Natal (2008): O PT e seus aliados

Este estudo faz uma abordagem sobre as alianças eleitorais, destacando duas vertentes importantes nos processos de suas formações nas arenas políticas. Na primeira parte do trabalho é feita uma análise mais geral a respeito da problemática em questão. Onde dois ciclos políticos são analisados, apresentando o comportamento político-partidário dos partidos no Brasil. No primeiro ciclo, uma breve compreensão da política café-com-leite na República Velha, na qual, PRP e PRM dominam politicamente a arena nacional. O segundo ciclo, compreendido de 1945 a 1964, foram analisados os processos eleitorais estaduais e nacionais. Nestes, os resultados analíticos mostram o que refletem no comportamento político-partidário dos partidos do passado e do presente no país. Outro aspecto importante também abordado na primeira parte foi a verticalização das alianças eleitorais, a qual teve como objetivo impor harmonia partidária entre os partidos nas formações das alianças eleitorais. Revendo esse processo político, vimos que, a imposição da verticalização não resolveu o problema da inexistência harmônica dos partidos no ato da formação das alianças eleitorais tocante ao espectro ideológico. A segunda parte da pesquisa está dividida em duas partes. A primeira faz uma análise sobre a trajetória política do PT e suas políticas de alianças, que se inicia no V Encontro Nacional do Partido em 1987. Como consequência da expansão partidária, outras políticas de alianças são aprovadas pelo Partido dos Trabalhadores. Na segunda parte, é trabalhada as eleições municipais de 2008 em Natal, que observa analiticamente a campanha do PT e as alianças eleitorais realizadas pelo Partido para participar do pleito. Os velhos adversários políticos e oligárquicos formaram alianças com PT. Partido que nasceu combatendo as velhas práticas da política conservadora no nosso país, nos estados e nos municípios brasileiros

The influence of physical activity in the progression of experimental lung cancer in mice

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Qualidade de vida, eficiência mastigatória e presença de disfunção temporomandibular em usuários de prótese parcial removível com arco dental curto inferior

Even nowadays there is in Brasil a large number of edentulous and a precarious financial condition of most of the population. In addition, World Health Organization aims for oral health, which consists on the maintenance of a natural dentition, functional and aesthetic composed of at least 20 teeth, without need of prosthetic intervention throughout life. From this and considering the lack of researches about the permanence of edentulous spaces in the oral cavity, and also avoiding overtreatment, this research has been proposed. Thus, the aim was to evaluate the effect of different lengths of the shortened lower dental arch in the presence or absence of a removable partial denture (RPD) on masticatory function, quality of life and occurrence of temporomandibular dysfunction. To achieve this goal, we compared the masticatory efficiency (colorimetric test), the oral comfort through the analysis of the impact of oral health in quality of life (OHIP-14), the presence of temporomandibular dysfunction (RDC/TMD) and the general quality of life (WHOQOL) of patients with shortened dental arches (SDA) (n=60), which is an arch with a reduction of teeth starting posteriorly, and patients with complete dental arch (Complete DA) (n = 34). The group of patients whit SDA was divided among PPR wears (PPD + SDA) (n = 17) and non-wears (n = 43). The population of this study consisted on patients who received or looked for treatment at the clinics of the Department of Dentistry of UFRN, from clinical analysis and records. The sample was chosen by convenience. For statistical analysis, it was a database in SPSS 17.0, followed by descriptive analysis with frequencies, absolute values, tests of central tendency and variability. The statistical tests used were chi-squared and analysis of variance as well as Tukey s post test, when applicable, all with a 95% confidence level. The results shown a prevalence of TMD of 47,1% among patients using PRP and 69,8% among those who didn t, but this result wasn t statistically significant. The mean of the results of masticatory efficiency, WHOQOL and OHIP didn t show association to the presence or absence of PPR and to the lower number of occlusal units of the patients (0, 1, 2 or more occlusal). The association only occurred among the different groups of SDA and the patients with complete dental arch. Taking into account the results, it could be observed that studied patients with low posterior support using lower PRP didn t have better masticatory efficiency, general quality of life, less impacts of their oral conditions in quality of life or not even less temporomandibular dysfunction or better masticatory efficiency when compared to those who didn t use the prosthesis

Platelet activation: ultrastructure and morphometry in platelet-rich plasma of horses

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Use of platelet-rich plasma under autogenous onlay bone grafts

Objectives: To analyze the healing of autogenous onlay bone grafts in three different situations, focusing on the interface area.Material and methods: Sixteen rabbits underwent autogenous bone graft surgeries in the calvaria. The block bone grafts were positioned in three different situations: direct contact between bone graft and receptor bed, graft interposed by particulate bone, and graft interposed by platelet-rich plasma (PRP). After 7, 15, 30, and 60 days, the specimens were retrieved for histological and morphometric evaluation.Results: All groups healed uneventfully and presented incorporation of the grafts after 30 days. A slightly more evident new bone formation could be observed in the PRP group in the first analyzed period, and an earlier maturation of bone in the last period, although no statistically significant differences were achieved.Conclusion: the use of additional material between the bone graft and the receptor bed when using the onlay technique must be carefully considered, taking into account the size of the reconstruction and the cost/benefit relation. The addition of PRP in between autogenous bone blocks and the receptor bed did not confer significant benefit for the new bone formation and healing on the calvaria of bone of rabbits.

Expression of apoptotic and cell proliferation regulatory proteins in keratoacanthomas and squamous cell carcinomas of the skin

The aim of this study was to investigate the expression of p53, caspase-3, bcl-2, MIB-1, and PCNA to validate more objective methods to differentiate squamous cell carcinoma and keratoacanthoma, as well as to understand their pathogenesis with accuracy. A total of 52 cases of histopathologically diagnosed keratoacanthoma in the proliferative stage and 56 cases of well-differentiated squamous cell carcinoma were selected in this study. The expression was evaluated by means of immunohistochemistry. Bcl-2 immunoreactivity was weak or absent in the majority of cases, either in squamous cell carcinoma or in keratoacanthoma. PCNA-positive cells did not show differences between two lesions evaluated. on the other hand, MIB-1 was statistically significant (p<0.05) between squamous cell carcinomas and keratoacanthomas. Moreover, p53 and caspase-3 were overexpressed in squamous cell carcinomas. Together, these results suggest that the biological behavior of the well-differentiated squanous cell carcinomas of the skin may be associated with cellular proliferation and/or deregulation of cell death, indicated by increased expression of the MIB-1 and apoptotic proteins p53 and caspase-3, respectively. (C) 2007 Elsevier GrnbH. All rights reserved.

Role of ROC1 protein in the control of cyclin D1 protein expression in skin melanomas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)