Treatment-Mediated Alterations in HIV Fitness Preserve CD4+ T Cell Counts but Have Minimal Effects on Viral Load

For most HIV-infected patients, antiretroviral therapy controls viral replication. However, in some patients drug resistance can cause therapy to fail. Nonetheless, continued therapy with a failing regimen can preserve or even lead to increases in CD4+ T cell counts. To understand the biological basis of these observations, we used mathematical models to explain observations made in patients with drug-resistant HIV treated with enfuvirtide (ENF/T-20), an HIV-1 fusion inhibitor. Due to resistance emergence, ENF was removed from the drug regimen, drug-sensitive virus regrown, and ENF was re-administered. We used our model to study the dynamics of plasma-viral RNA and CD4+ T cell levels, and the competition between drug-sensitive and resistant viruses during therapy interruption and re-administration. Focusing on resistant viruses carrying the V38A mutation in gp41, we found ENF-resistant virus to be 17±3% less fit than ENF-sensitive virus in the absence of the drug, and that the loss of resistant virus during therapy interruption was primarily due to this fitness cost. Using viral dynamic parameters estimated from these patients, we show that although re-administration of ENF cannot suppress viral load, it can, in the presence of resistant virus, increase CD4+ T cell counts, which should yield clinical benefits. This study provides a framework to investigate HIV and T cell dynamics in patients who develop drug resistance to other antiretroviral agents and may help to develop more effective strategies for treatment

Percepção de professores de odontologia no processo de ensino-aprendizagem Perceptions of dentistry teachers in the teaching and learning process

Há necessidade de se pesquisar a formação didático-pedagógica do professor universitário e a qualidade da educação superior em decorrência das demandas da sociedade em mudança e da implantação das diretrizes curriculares nacionais. Analisa-se a percepção de docentes do curso de graduação em odontologia da Universidade Estadual de Londrina a respeito do papel do professor no processo ensino-aprendizagem. Adotou-se a abordagem qualitativa e a entrevista semiestruturada para a geração de dados. O estudo revelou que o professor tem um papel fundamental no processo de ensino-aprendizagem, sendo considerado responsável pela transmissão do conhecimento. As estratégias de ensino-aprendizagem se baseiam em exposições orais. Grande parte dos professores só teve formação didático-pedagógica nos cursos de mestrado e/ou doutorado, que não capacitam suficientemente os docentes para o exercício do magistério. A maioria dos professores não possui formação específica em educação. Conclui-se que há uma necessidade de rever tanto a formação quanto a atualização didático-pedagógica do professor universitário para que se possa buscar uma formação generalista, humanista, crítica e reflexiva do estudante.<br>The didactic-pedagogical training of the university professor and of the quality of higher education must be revised due to the demands of the dynamic society and to the implementation of national curricular guidelines. Within this context, it was analyzed the perceptions of dentistry undergraduate of Universidade Estadual de Londrina teachers about the role of the teacher in the teaching and learning process. A qualitative research was carried out and data were collected through semi-structured interviews. Results showed that the teacher plays an essential role in the teaching and learning process, being the sole provider of knowledge. Teaching and learning strategies are based on oral transmission. Most part of the teachers got their didactic-pedagogical education from postgraduate Courses (Master's and/or PhD), that do not qualify teachers adequately for their teaching career. The teachers are not formally prepared for their teaching careers. In conclusion, findings from this study must be revised both regarding the training and the didactic-pedagogical upgrading in search of a general, humanist, critical and reflexive formation of the student