Several studies have investigated the differential vulnerability of hippocampal subfields during aging and Alzheimer's disease (AD). Results were often contradictory, mainly because these works were based on concatenations of cross-sectional measures in cohorts with different ages or stages of AD, in the absence of a longitudinal design. Here, we investigated 327 participants from a population-based cohort of non-demented older adults with a 14-year clinical follow-up. MRI at baseline and 4 years later were assessed to measure the annualized rates of hippocampal subfields atrophy in each participant using an automatic segmentation pipeline with subsequent quality-control. In the one hand, CA4-dentate gyrus was significantly more affected than the other subfields in the whole population (CA1-3:-0.68%/year; subiculum:-0.99%/year and CA4-DG:-1.39%/year; p<0.0001). In the other hand, the annualized rate of CA1-3 atrophy was associated with an increased risk of developing Alzheimer's clinical syndrome over time, independently of age, gender, educational level and ApoE4 genotype (HR=2.0; IC95% 1.4-3.0). These results illustrate the natural history of hippocampal subfields atrophy during aging and AD by showing that the dentate gyrus is the most vulnerable subfield to the effects of aging while the cornu-ammonis is the primary target of AD pathophysiological processes, years prior to symptom onset.

The objective of the present study was to study the prevalence of abnormal anal cytology in patients with AIDS. Anal smears, obtained with a cytobrush, of 102 HIV-positive patients of the Emilio Ribas Institute (Sao Paulo, Brazil) were collected, and only after that, the patients were submitted to anoscopy. Thirty-two patients had LSIL and 14 others had HSIL. Squamous intra-epithelial lesions were also observed in 38% of the patients without condyloma (18/47): in 9 of the 33 patients without history of condyloma (27%) and in 9 of the 14 patients who had previously treated condyloma (64%). An invasive squamous cell carcinoma was observed in one patient without history of condyloma. In all 13 patients with HSIL, biopsies guided by high resolution anoscopy confirmed high grade dysplasia. Our findings suggest that anal cytology is mandatory in AIDS even in patients without macroscopic anal lesions or without previous history of anal condyloma.