RESUMO
The idea of biological evolution is not accepted by many people around the world, with a large disparity amongst countries. Some factors may act as obstacles to the acceptance of evolution, such as religion, a lack of openness to experience, and not understanding the nature of science. Although the strength of the association between evolution acceptance and non-scientific factors varies among studies, it is often assumed that resistance to evolution is the byproduct of a religious background. Some studies are even more specific and try to associate the acceptance of evolution with precise religious affiliations. We aimed to explore the strength of associations among nationality, religion, and the acceptance of evolution by students using multiple correspondence analysis (MCA) and statistical tools, with nationwide samples from two different countries. Here, we show that wider sociocultural factors predict the acceptance of evolution to a higher degree than a religious background. We carried out two nationwide data collections that allowed us to compare differences in the acceptance of evolution in Italy and Brazil by high school students who declare to belong to the same religion in the two countries. Roman Catholic students showed significant differences between the two countries, and the gap between them was wider than between Catholics and non-Catholic Christians within Brazil. Our conclusions support those who argue that religious affiliation is not the main factor in predicting the level of evolution acceptance. The sociocultural environment and the level of evolutionary knowledge seem to be more important in this regard. These results open up new interpretative perspectives and provide a better understanding of attitudes towards evolution.
Assuntos
Atitude , Estudantes , Brasil , Catolicismo , Humanos , ItáliaRESUMO
Biological evolution is often regarded as a central and unifying axis of biology. This article discusses historical aspects of this ideal of unification, as well as signs of its disintegration from the 1960s to 1980s. We argue that despite new proposals for the synthesis of biological knowledge, contemporary evolutionary biology is characterized by pluralism. The main points in favor of evolutionary pluralism are discussed and some consequences of this perspective are presented, particularly in terms of the ideal of a unified biology. Finally, we defend an evolutionary pluralism that critiques the ideal of unification as a scientific objective, but still favors local integrations.
A evolução biológica é frequentemente considerada um eixo central e unificador da biologia. O artigo discute aspectos históricos desse ideal de unificação, bem como os seus sinais de desintegração entre os anos 1960 e 1980. Argumentamos que apesar das novas propostas de síntese do conhecimento biológico, a biologia evolutiva contemporânea é caracterizada por um pluralismo. Os principais pontos a favor do pluralismo evolutivo são discutidos, e algumas consequências dessa perspectiva são apresentadas, particularmente em relação ao ideal de unificação da biologia. Por fim, defendemos um pluralismo evolutivo crítico do ideal de unificação como um objetivo da ciência, mas ainda favorável a integrações locais.
RESUMO
Resumo A evolução biológica é frequentemente considerada um eixo central e unificador da biologia. O artigo discute aspectos históricos desse ideal de unificação, bem como os seus sinais de desintegração entre os anos 1960 e 1980. Argumentamos que apesar das novas propostas de síntese do conhecimento biológico, a biologia evolutiva contemporânea é caracterizada por um pluralismo. Os principais pontos a favor do pluralismo evolutivo são discutidos, e algumas consequências dessa perspectiva são apresentadas, particularmente em relação ao ideal de unificação da biologia. Por fim, defendemos um pluralismo evolutivo crítico do ideal de unificação como um objetivo da ciência, mas ainda favorável a integrações locais.
Abstract Biological evolution is often regarded as a central and unifying axis of biology. This article discusses historical aspects of this ideal of unification, as well as signs of its disintegration from the 1960s to 1980s. We argue that despite new proposals for the synthesis of biological knowledge, contemporary evolutionary biology is characterized by pluralism. The main points in favor of evolutionary pluralism are discussed and some consequences of this perspective are presented, particularly in terms of the ideal of a unified biology. Finally, we defend an evolutionary pluralism that critiques the ideal of unification as a scientific objective, but still favors local integrations.
Assuntos
Biologia/história , Consenso , Evolução Biológica , História do Século XXRESUMO
BACKGROUND: Although most HIV-1 infections in Brazil are due to subtype B, Southern Brazil has a high prevalence of subtype C and recombinant forms, such as CRF31_BC. This study assessed the impact of viral diversity on clinical progression in a cohort of newly diagnosed HIV-positive patients. METHODS: From July/2004 to December/2005, 135 HIV-infected patients were recruited. The partial pol region was subtyped by phylogeny. A generalized estimating equation (GEE) model was used to examine the relationship between viral subtype, CD4+ T cell count and viral load levels before antiretroviral therapy. Hazard ratio (Cox regression) was used to evaluate factors associated with viral suppression (viral load < 50 copies/mL at six months). RESULTS: Main HIV-1 subtypes included B (29.4%), C (28.2%), and CRF31_BC (23.5%). Subtypes B and C showed a similar trend in CD4+ T cell decline. Comparison of non-B (C and CRF31_BC) and B subtypes revealed no significant difference in the proportion of patients with viral suppression at six months (week 24). Higher CD4+ T cell count and lower viral load were independently associated with viral suppression. CONCLUSION: No significant differences were found between subtypes; however, lower viral load and higher CD4+ T cell count before therapy were associated with better response.
Assuntos
Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , Adulto , Contagem de Linfócito CD4 , Progressão da Doença , Feminino , Genótipo , HIV-1/classificação , HIV-1/genética , Humanos , Masculino , Filogenia , Estudos Prospectivos , Carga ViralRESUMO
Entry of HIV-1 into a host cell is a multi-step process, with the viral envelope gp120 and gp41 acting sequentially to mediate the viral attachment, CD4 binding, coreceptor binding, and fusion of the viral and host membranes. The emerging class of antiretroviral agents, collectively known as entry inhibitors, interfere in some of these steps. However, viral diversity has implications for possible differential responses to entry inhibitors, since envelope is the most variable of all HIV genes. Different HIV genetic forms carry in their genomes genetic signatures and polymorphisms that could alter the structure of viral proteins which are targeted by drugs, thus impairing antiretroviral binding and efficacy. This review will examine current research that describes subtype differences in envelope at the genetic level and the effects of mutations on the efficacy of current entry inhibitors.
Assuntos
HIV-1/fisiologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo , Farmacorresistência Viral/genética , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/metabolismo , Inibidores da Fusão de HIV/farmacologia , HIV-1/efeitos dos fármacos , Humanos , Internalização do Vírus/efeitos dos fármacos , Produtos do Gene env do Vírus da Imunodeficiência Humana/genéticaRESUMO
BACKGROUND: Entry inhibitors are a class of antiretroviral (ARV) drugs that prevent HIV replication by blocking viral entry into the host cell. The investigation of naturally occurring mutations associated with entry inhibitors across subtypes is required because genetic differences between HIV-1 variants may influence the emergence of drug resistance. Despite the importance of subtype C, which predominates globally, the majority of studies include only subtype B strains. OBJECTIVES: To investigate the presence of natural resistance mutations to entry inhibitors in HIV-1 subtypes B, C, and CRF31_BC strains. STUDY DESIGN: Eighty samples were collected from antiretroviral-naïve patients. The gp41 gene from 67 patients and the gp120 gene from 65 patients were partially sequenced. Resistance mutations to entry inhibitors Enfuvirtide, Maraviroc, and Vicriviroc were screened. RESULTS: ENF resistance-associated mutations of HR1 and HR2 on gp41 were not associated with any subtype. However, the major polymorphisms detected in HR1: N42S, L54M, and A67T were most prevalent in subtype C (p<0.001). Mutations A316T and R315Q in gp120, which are related to MVC and VCV reduced susceptibility respectively, were predominant in subtype C (p<0.05). CONCLUSIONS: This study shows that many more resistance-associated mutations to entry inhibitors in ARV-naïve patients occur in subtype C compared with subtype B strains. However, further studies will be necessary to elucidate if the differential genetic background of HIV subtypes can affect the efficacy of treatment with entry inhibitors.
Assuntos
Farmacorresistência Viral , Inibidores da Fusão de HIV/farmacologia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Mutação de Sentido Incorreto , Substituição de Aminoácidos , Genótipo , Proteína gp120 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/genética , HIV-1/classificação , HIV-1/isolamento & purificação , Humanos , Análise de Sequência de DNARESUMO
The dispersal of HIV-1 subtype B (HIV-1B) is a reflection of the movement of human populations in response to social, political, and geographical issues. The initial dissemination of HIV-1B outside Africa seems to have included the passive involvement of human populations from the Caribbean in spreading the virus to the United States. However, the exact pathways taken during the establishment of the pandemic in the Americas remain unclear. Here, we propose a geographical scenario for the dissemination of HIV-1B in the Americas, based on phylogenetic and genetic statistical analyses of 313 available sequences of the pol gene from 27 countries. Maximum likelihood and bayesian inference methods were used to explore the phylogenetic relationships between HIV-1B sequences, and molecular variance estimates were analyzed to infer the genetic structure of the viral population. We found that the initial dissemination and subsequent spread of subtype B in the Americas occurred via a single introduction event in the Caribbean around 1964 (1950-1967). Phylogenetic trees present evidence of several primary outbreaks in countries in South America, directly seeded by the Caribbean epidemic. Cuba is an exception insofar as its epidemic seems to have been introduced from South America. One clade comprising isolates from different countries emerged in the most-derived branches, reflecting the intense circulation of the virus throughout the American continents. Statistical analysis supports the genetic compartmentalization of the virus among the Americas, with a close relationship between the South American and Caribbean epidemics. These findings reflect the complex establishment of the HIV-1B pandemic and contribute to our understanding between the migration process of human populations and virus diffusion.
Assuntos
Infecções por HIV/história , Infecções por HIV/transmissão , HIV-1/genética , América/epidemiologia , Sequência de Bases , Teorema de Bayes , Infecções por HIV/classificação , Infecções por HIV/virologia , HIV-1/isolamento & purificação , História do Século XX , Humanos , FilogeniaRESUMO
Background: Although most HIV-1 infections in Brazil are due to subtype B, Southern Brazil has a high prevalence of subtype C and recombinant forms, such as CRF31_BC. This study assessed the impact of viral diversity on clinical progression in a cohort of newly diagnosed HIV-positive patients. Methods: From July/2004 to December/2005, 135 HIV-infected patients were recruited. The partial pol region was subtyped by phylogeny. A generalized estimating equation (GEE) model was used to examine the relationship between viral subtype, CD4+ T cell count and viral load levels before antiretroviral therapy. Hazard ratio (Cox regression) was used to evaluate factors associated with viral suppression (viral load < 50 copies/mL at six months). Results: Main HIV-1 subtypes included B (29.4%), C (28.2%), and CRF31_BC (23.5%). Subtypes B and C showed a similar trend in CD4+ T cell decline. Comparison of non-B (C and CRF31_BC) and B subtypes revealed no significant difference in the proportion of patients with viral suppression at six months (week 24). Higher CD4+ T cell count and lower viral load were independently associated with viral suppression. Conclusion: No significant differences were found between subtypes; however, lower viral load and higher CD4+ T cell count before therapy were associated with better response.
Introdução: Embora a maioria das infecções de HIV-1 no Brasil seja devido ao subtipo B, o Sul do Brasil apresenta uma alta prevalência do subtipo C e formas recombinantes, como CRF31_BC. Este estudo avaliou o impacto da diversidade viral na evolução clínica em uma coorte de pacientes HIV-positivos recém diagnosticados. Métodos: De julho/2004 a dezembro/2005, 135 pacientes anti-HIV reagentes foram recrutados. A região pol parcial foi subtipada por filogenia. Um modelo de equação de estimativa generalizada (GEE) foi utilizado para examinar a relação entre subtipo viral, contagem de células CD4 e níveis de carga viral pré-terapia antirretroviral. Hazard ratio (regressão de Cox) foi utilizada para avaliar os fatores associados à supressão viral (carga viral < 50 cópias/mL em seis meses). Resultados: Os principais subtipos de HIV-1 incluíram B (29,4%), C (28,2%) e CRF31_BC (23,5%). Os subtipos B e C apresentaram uma tendência semelhante no declínio de células CD4. Quando comparados os subtipos não B (C e CRF31_BC) e B, não houve diferença significativa na proporção de pacientes com supressão viral aos seis meses (24 semanas). CD4 mais alto e carga viral mais baixa demonstraram associação independente com supressão viral. Conclusão: Não houve diferença significativa entre os subtipos; entretanto, viremia mais baixa e CD4 mais alto pré-terapia mostraram associação com melhor resposta.