OBJECTIVE To evaluate the prevalence of late HIV diagnosis (CD4<200 cell/mm³) in an HIV clinic in Mexico City between 2001-2008, to assess changes in this prevalence across the study period, and to determine the risk factors associated to late testing (LT). MATERIALS AND METHODS Cross-sectional analysis including all patients recently diagnosed as HIV. We estimated the proportion of LT patien...

PURPOSE To evaluate the differences in accommodative function between subjects with emmetropia and those with late-onset myopia (LOM). METHODS This study suggests a modified model of static accommodation, in which an accommodative sensory gain as a linear operator is added to simulate the sensory part of the system. Results derived from the model show that the sensory part not only affects th...

Alzheimer's disease is characterized by abnormal elevation of Abeta peptide and abnormal hyperphosphorylation of the tau protein. The "amyloid hypothesis," which is based on molecular defects observed in autosomal-dominant early-onset Alzheimer's disease (EOAD), suggests a serial model of causality, whereby elevation of Abeta drives other disease features including tau hyperphosphorylation. Her...

BACKGROUND Biotin, a water-soluble vitamin, is used as a co-factor by enzymes involved in carboxylation reactions. Biotinidase (BTD) catalyzes the recycling of biotin from endogenous and dietary sources. Biotinidase deficiency (BD) is an autosomal recessively inherited disorder of biotin recycling that is associated with neurologic and cutaneous consequences when untreated. The aim of the study...