Plasmodium berghei ANKA infection induces thymocyte apoptosis and thymocyte depletion in CBA mice

Immune responses to malaria infections are characterized by strong T and B cell activation, which, in addition of potentially causing immunopathology, are of poor efficacy against the infection. It is possible that the thymus is involved in the origin of immunopathological reactions and a target during malaria infections. This work was developed in an attempt to further clarify these points. We studied the sequential changes in the thymus of CBA mice infected with Plasmodium berghei ANKA, a model in which 60-90% of the infected animals develop cerebral malaria. During the acute phase of infection, different degrees of thymocyte apoptosis were recorded: (1) starry-sky pattern of diffuse apoptosis with maintenance of cortical-medullary structure; (2) intense apoptosis with cortical atrophy, with absence of large cells; (3) severe cortical thymocyte depletion, resulting in cortical-medullary inversion. In the latter, only residual clusters of small thymocytes were observed within the framework of epithelial cells. The intensity of thymus alterations could not be associated with the degree of parasitemia, the expression of clinical signs of cerebral malaria or intensity of brain lesions. The implications of these events for malaria immunity and pathology are discussed.

Immune and inflammatory responses to Leishmania amazonensis isolated from different clinical forms of human leishmaniasis in CBA mice

Leishmania amazonensis causes different diseases depending on the host and parasitic virulence factors. In this study, CBA mice were infected with L. amazonensis isolates from patients with localized (Ba125), diffuse cutaneous (Ba276) or visceral leishmaniasis (Ba109). Mice infected with Ba125 and Ba276 progressed rapidly and lesions displayed an infiltrate rich in parasitized macrophages and were necrotic and ulcerated. Ba109 induced smaller lesions and a mixed inflammatory infiltrate without necrosis or ulceration. Ba109 induced an insidious disease with lower parasite load in CBA mice, similar to human disease. Levels of IFN-γ, IL-4 and IL-10 did not differ among the groups. Because all groups were unable to control the infection, expression of IL-4 associated with low production of IFN-γ in the early phase of infection may account for susceptibility, but others factors may contribute to the differences observed in inflammatory responses and infection progression. Evaluation of some parasitic virulence factors revealed that Ba276 exhibits higher ecto-ADPase and 5'-nucleotidase activities compared to the Ba109 and Ba125 strains. Both Ba276 and Ba125 had higher arginase activity in comparison to Ba109. Finally, these data suggest that the differences in enzyme activities among parasites can account for differences in host inflammatory responses and infection progression.

Implementação do Custeio baseado em Actividade (CBA) numa Empresa

Os sistemas de custeio não são mais do que sistemas de informação e de suporte à tomada de decisão. Porém, a contestação em relação aos sistemas ditos de tradicionais levou à emergência de novas abordagens. Dentre todas, o Custeio Baseado nas Actividades (ABC) tem-se destacado ao nível da literatura e das próprias empresas, sobretudo nas de maiores dimensões. A compreensão e a aplicação do ABC, em especial nas PMEs e a sistematização de metodologias de implementação, assim como a elaboração de estudos que concluam das reais vantagens e desvantagens deste novo sistema são, ainda, um campo por explorar devidamente. Este trabalho procura estudar a validade de um sistema ABC ao nível de uma PME Caboverdiana, caracterizadas na sua maior parte por um grande desconhecimento em relação às técnicas e abordagens de custeio. Para além do trabalho de campo (Parte IV) que aqui é descrito também se realizou um estudo exaustivo da literatura sobre o tema (Parte III). Porém, o ABC não poderia ser entendido, descontextualizado da problemática dos custos e dos sistemas de custeio (Parte I), nem desenquadrado do conjunto de mudanças que se operaram nos últimos anos nos processos produtivos e que proporcionaram o surgimento de outras abordagens não menos interessantes (Parte II). O estudo de caso, consubstanciado na última parte, visou criar um quadro conceptual de referência que permita a realização de outros estudos semelhantes, alargando o conhecimento científico sobre este tema e providenciando ferramentas úteis para as empresas que seguem de perto estas novas abordagens.

Implementação do sistema de custeio baseado em actividades (CBA) numa Instituição de Ensino Superior em Cabo Verde

Actualmente, a gestão de gastos assume um papel fundamental nas empresas modernas. A globalização, aliada às novas tecnologias, exige que essas empresas sejam ágeis e competentes. Neste contexto, a gestão eficiente dos recursos e a obtenção de informações precisas que apoiem na tomada de decisão, dependerão em grande parte, de um sistema de custo. A utilização de diversas tecnologias e ferramentas faz com que as empresas tenham cada vez mais gastos indiretos relativamente aos gastos diretos. Logo, o método CBA surgiu como alternativa aos sistemas de custeio tradicionais numa tentativa de solucionar ou, pelo menos, minimizar o problema de atribuição dos gastos indiretos. O presente trabalho pretende abordar o método CBA e propor uma metodologia de implementação do sistema numa Instituição de Ensino Superior, evidenciando e discutindo as principais vantagens e desvantagens associadas a esta metodologia e identificando as suas contribuições para a gestão das IES. De acordo com as pesquisas feitas, conclui-se que nenhuma das IES em São Vicente possui um sistema de contabilidade de gestão, mas verificou-se que todas têm conhecimento deste sistema e consideram-no o melhor método de gestão para análise dos gastos. Os resultados obtidos no estudo de caso demonstram que o objetivo foi atingido, apurandose que o método CBA é o mais adequado para o suporte à gestão, tendo em conta que ultrapassa as insuficiências de informação sobre os gastos. Currently, cost management plays a key role in modern business. The globalization, allied to the new technologies, demands that those companies are agile and qualified. In this context, an efficient management of the resources and the gathering of precise information which support the decision-making process will depend, largely, of an effective cost management system. The use of different technologies and tools makes companies have more indirect costs than direct. Therefore, the ABC method was devised as an alternative to the conventional means of costing in an attempt of solving or, at least, minimizing the problem of the attribution of indirect costs. Our work intends to analyze the ABC method and to propose a methodology of implementation of such system in an Institution of Higher Education, showing and discussing the main advantages and disadvantages associated with this methodology and identifying its contributions for the administration of these Institutions. Our research has shown that, none of the IHEs in São Vicente has a management accounting system, although all have knowledge of it and consider it as being the best administration method for the analysis of expenses. The results obtained in the case study demonstrate that the objective was reached: to conclude the ABC method is the most adequate to support the administration, as it overcomes the problem of lack of information on the running costs.

El impacto del costeo basado en actividades (CBA), en el desempeño de las empresas manufactureras del sector acero de México.

Tesis (Doctorado en Contaduría) UANL, 2011.

Marginal cell density in young and old CBA/J and CBA/CAJ mice

The goal of the present study was to compare aging characteristics of the cochlear lateral wall in inbred mouse strains (CBA/J and CBA/CaJ) having very different endocochlear potential (EP)-versus-age profiles to see which anatomic differences might predict their EP differences.

Synergistic effects of noise, kanamycin, and hyperoxia on ABR thresholds in CBA/J mice

Young CBA/J mice were exposed to noise, kanamycin, and/or hyperoxia by 30 days post-gestational age in order to determine if a synergistic effect exists on ABR thresholds.

Differential Effects on Survival, Humoral Immune Responses and Brain Lesions in Inbred BALB/C, CBA/CA, and C57BL/6 Mice Experimentally Infected with Neospora caninum Tachyzoites

C57BL/6, BALB/c, and CBA/Ca mouse strains with different MHC-I haplotypes were compared with respect to susceptibility to Neospora caninum infection. Groups of 5 mice received , , or tachyzoites of the NC-Liverpool isolate by intraperitoneal injection and were observed for disease symptoms. Humoral responses, splenocyte interferon-γ (IFN-γ) production, cerebral parasite loads, and histopathology were evaluated at human end points or the latest at 34 days postinfection (PI). The mortality rates in C57BL/6 mice were the highest, and relatively high levels of IgG1 antibodies were detected in those mice surviving till 34 days PI. In lymphocyte proliferation assays, spleen cells from C57BL6 mice stimulated with N. caninum antigen extract exhibited large variations in IFN-γ production. In BALB/c mice mortality was 0% at the lowest and 100% at the highest infection dose. Serologically they responded with high levels of both IgG2a and IgG1 subclasses, and lymphocyte proliferation assays of surviving mice yielded lower IFN-γ levels. CBA/Ca mice were the most resistant, with no animal succumbing to infection at a dose of and tachyzoites, but 100% mortality at tachyzoites. High IgG2a levels as well as increased IFN-γ in lymphocyte proliferation assays were measured in CBA/Ca mice infected with tachyzoites.

Caturelli, Alberto: La filosofía medieval, Córdoba, Univ. Nac. Cba., 1972.

Fil: Ares, Consuelo.

Cationic Bovine Serum Albumin (CBA) conjugated Poly Lactic-co-Glycolic Acid (PLGA) nanoparticles for extended delivery of methotrexate into brain tumor

Current treatment strategies for the treatment of brain tumor have been hindered primarily by the presence of highly lipophilic insurmountable blood-brain barrier (BBB). The purpose of current research was to investigate the efficiency of engineered biocompatible polymeric nanoparticles (NPs) as drug delivery vehicle to bypass the BBB and enhance biopharmaceutical attributes of anti-metabolite methotrexate (MTX) encapsulated NPs. The NPs were prepared by solvent diffusion method using cationic bovine serum albumin (CBA), and characterized for physicochemical parameters such as particle size, polydispersity index, and zeta-potential; while the surface modification was confirmed by FTIR, and NMR spectroscopy. Developed NPs exhibited zestful relocation of FITC tagged NPs across BBB in albino rats. Further, hemolytic studies confirmed them to be non-toxic and biocompatible as compared to free MTX. In vitro cytotoxicity assay of our engineered NPs on HNGC1 tumor cells proved superior uptake in tumor cells; and elicited potent cytotoxic effect as compared to plain NPs and free MTX solution. The outcomes of the study evidently indicate the prospective of CBA conjugated poly (D,L-lactide-co-glycolide) (PLGA) NPs loaded with MTX in brain cancer bomber with amplified capability to circumvent BBB.

Respiratory allergy to Blomia tropicalis: Immune response in four syngeneic mouse strains and assessment of a low allergen-dose, short-term experimental model

Background: The dust mite Blomia tropicalis is an important source of aeroallergens in tropical areas. Although a mouse model for B. tropicalis extract (BtE)-induced asthma has been described, no study comparing different mouse strains in this asthma model has been reported. The relevance and reproducibility of experimental animal models of allergy depends on the genetic background of the animal, the molecular composition of the allergen and the experimental protocol. Objectives: This work had two objectives. The first was to study the anti-B. tropicalis allergic responses in different mouse strains using a short-term model of respiratory allergy to BtE. This study included the comparison of the allergic responses elicited by BtE with those elicited by ovalbumin in mice of the strain that responded better to BtE sensitization. The second objective was to investigate whether the best responder mouse strain could be used in an experimental model of allergy employing relatively low BtE doses. Methods: Groups of mice of four different syngeneic strains were sensitized subcutaneously with 100 mu g of BtE on days 0 and 7 and challenged four times intranasally, at days 8, 10, 12, and 14, with 10 mu g of BtE. A/J mice, that were the best responders to BtE sensitization, were used to compare the B. tropicalis-specific asthma experimental model with the conventional experimental model of ovalbumin (OVA)-specific asthma. A/J mice were also sensitized with a lower dose of BtE. Results: Mice of all strains had lung inflammatory-cell infiltration and increased levels of anti-BtE IgE antibodies, but these responses were significantly more intense in A/J mice than in CBA/J, BALB/c or C57BL/6J mice. Immunization of A/J mice with BtE induced a more intense airway eosinophil influx, higher levels of total IgE, similar airway hyperreactivity to methacholine but less intense mucous production, and lower levels of specific IgE, IgG1 and IgG2 antibodies than sensitization with OVA. Finally, immunization with a relatively low BtE dose (10 mu g per subcutaneous injection per mouse) was able to sensitize A/J mice, which were the best responders to high-dose BtE immunization, for the development of allergy-associated immune and lung inflammatory responses. Conclusions: The described short-term model of BtE-induced allergic lung disease is reproducible in different syngeneic mouse strains, and mice of the A/J strain was the most responsive to it. In addition, it was shown that OVA and BtE induce quantitatively different immune responses in A/J mice and that the experimental model can be set up with low amounts of BtE.