Prevalence Rates of Mental Disorders in Chilean Prisons

PMCID: PMC371883

The underlying mechanisms for the 'anti-HBc alone' serological profile

Abstract The serological pattern, ''anti-HBc alone'', characterized by the presence of antibodies against the core antigen of hepatitis B virus (anti-HBc) as the only marker of hepatitis B, is not rare in a diagnostic setting. Depending on the prevalence of HBV infection and the patient group investigated, 1-31% of positive anti-HBc results are isolated positive findings. Anti-HBc alone is frequently observed in intravenous drug addicts, HIV-infected individuals, patients who are coinfected with HBV and hepatitis C virus, and pregnant women. However, it is not clear how this profile should be interpreted. Several studies have shown that anti-HBc alone is not only compatible with acute and resolved HBV infection but also with chronic infection. The reasons for the lack of HBsAg and anti-HBs in anti-HBc-alone individuals are not clear, but several mechanisms and possibilities have been suggested that could explain this phenomenon, some of which are delineated in this article

Eficácia da memantina na doença de Alzheimer em seus estágios moderado a grave Efficacy of memantine in moderate to severe Alzheimer disease

INTRODUÇÃO: O objetivo desta revisão de literatura é avaliar a eficácia, a segurança e a tolerabilidade da memantina, um antagonista não-competitivo do receptor N-metil-D-aspartato (NMDA), no tratamento da doença de Alzheimer em seus estágios moderado a grave. MÉTODOS: Realizou-se uma busca no banco de dados MEDLINE com as palavras-chave memantine e Alzheimer's disease, sendo inseridos apenas ensaios clínicos randomizados, duplo-cegos e controlados com placebo. RESULTADOS: Foram incluídos quatro estudos que preenchiam os critérios de inclusão supracitados, realizados com pacientes portadores de doença de Alzheimer com grau moderado a grave. Todos os estudos indicaram um efeito benéfico da memantina com relação ao placebo para os seguintes parâmetros: melhora da capacidade funcional e maior participação nas atividades diárias. Dois estudos evidenciaram melhora cognitiva. A duração média dos estudos foi de 28 semanas e as doses mais eficazes variaram de 10 a 20mg/dia. Os efeitos adversos, em todos os estudos, foram maiores no grupo placebo. DISCUSSÃO: Apesar de ser uma droga nova e ainda de custo elevado, a memantina parece reduzir os custos totais e o tempo gasto do cuidador, além de produzir melhora global do paciente, gerando melhor qualidade de vida tanto para o paciente quanto para o cuidador. Estudos ainda não publicados, contudo, sugerem que o impacto dessa droga nos estágios mais avançados da demência de Alzheimer seja marginal.<br>INTRODUCTION: The aim of this systematic review is to evaluate efficacy, safety and tolerability of memantine, a non-competitive agonist of N-methyl-D-aspartate (NMDA) receptor, on the treatment of moderate to severe Alzheimer disease. METHODS: A search in MEDLINE database was made using key words memantine and Alzheimer's disease. Only randomized, double-blinded and placebo controlled clinical trials were included. RESULTS: Four studies were found that fulfilled inclusion criteria; all patients had moderate or severe Alzheimer disease. All studies suggested that memantine is superior to placebo for the following parameters: improvement in functional abilities and more participation in daily activities. Two studies suggestted cognitive improvement. Mean duration of studies was 28 weeks, and doses of memantine ranged between 10 to 20mg/bid. Side effects, in all studies, were worst for placebo group. DISCUSSION: In spite of its costs, memantine seems to reduce total costs and time spent by caregiver, and improves patient and caregiver quality of life