Fatal disseminated toxoplasmosis during primary HIV infection

Toxoplasmosis is a well recognized manifestation of AIDS, but the disseminated disease is a rare condition and it has not been associated to HIV seroconversion to our knowledge. We describe a fatal episode of disseminated T. gondii acute infection with massive organ involvement during primary HIV infection. The serological data demonstrate primary T. gondii infection. The avidity index for HIV antibodies supports recent HIV-1 infection.     

Neuroimaging and APOE genotype: a systematic qualitative review

Apolipoprotein E (APOE) is the major genetic risk factor for late-onset Alzheimer's disease (AD) and has also been implicated in cardiovascular disease, cognitive decline and cognitive changes in healthy ageing. The aim of this paper is to systematically review and critically assess the association between the APOE genotype and structural/functional cerebral changes as evidenced by brain imaging studies. A second aim is to determine whether these observed associations between APOE and the brain reflect changes which are consistent with the progression of AD neurodegenerative changes described in Braak stages. A search of Pubmed, Psycinfo, and Web of Science databases identified 64 articles available for qualitative review. The review found that presence of the APOE epsilon4 allele is associated with (1) hippocampal, amygdalar and entorhinal cortex atrophy, (2) increased brain atrophy, (3) increased white matter hyperintensity volumes and (4) altered cerebral blood flow and glucose metabolism patterns. It is possible that there are critical age ranges when these effects are evident and that the APOE epsilon2 genotype might present a risk. We conclude that structural brain change is associated with the APOE genotype and that it is more salient in younger ageing individuals.     

Hemispheric contribution to categorical and coordinate representational processes: a study on brain-damaged patients

According to Kosslyn, two types of spatial relations can be used to arrange parts in mental imagery, i.e., categorical spatial relations and coordinate spatial relations, which are processed respectively by the left and right hemispheres. To investigate this possible hemispheric specialization in the imagery domain, we tested 34 left or right brain-damaged patients using both a categorical and a coordinate mental imagery task. The results show that left brain-damaged patients were selectively impaired on processing categorical representations, while right brain-damaged patients were more impaired on the processing the coordinate ones, regardless of the presence of visuo-spatial neglect. The present study partly support Kosslyn's theory and, despite data reported in previous studies of brain-damaged patients, it also supports the hypothesis of a possible bilateral neural representation of mental imagery, with the two hemispheres taking part in this process in different ways.     

Gender differences in the endorsement of symptoms for depression and anxiety: are gender-biased items responsible?

Gender-biased items are one explanation for the gender difference in reports of depression and anxiety symptoms. This hypothesis was explored using responses from the Goldberg Anxiety and Depression scales. Responses were drawn from 2 waves of a community-based survey with participants in 3 age cohorts: 20 to 25, 40 to 44, and 60 to 64 at wave 1. The results showed that a 2-factor model fitted the scales well. Multiple group analyses showed that that for all 3 age groups and both time points the fit indices changed minimally between a model that constrained parameters to be equal across gender and a model that permitted variation. These findings indicate that gender differences in the endorsement of items from the Goldberg scales are not because of gender-biased items. This study points to alternate biopsychosocial explanations and highlights the importance of choosing appropriate methods of analysis when assessing item bias.     

Strain and schedule-dependent differences in the acquisition, maintenance and extinction of intravenous cannabinoid self-administration in rats

Cannabinoids have been reported to sustain self-administration in laboratory animals; however, genetic differences and environmental factors critical in the initiation and retention of such behaviour are yet to be defined. This study investigated the acquisition, maintenance and extinction of self-administration of the cannabinoid CB1 receptor agonist WIN 55,212-2 (6.25-25 microg/kg/inf) in Long Evans, Lister Hooded and Sprague-Dawley rats under a continuous schedule of reinforcement and two different response-like operanda, nose-poking and lever-pressing. Results showed that Long Evans and Lister Hooded, but not Sprague Dawley, rats acquired and retained stable cannabinoid self-administration behaviour under both modus operandi, as defined by significant differences between responding in the active versus the inactive hole/lever. In rats developing firm self-administration, substitution of saline for WIN 55,212-2 extinguished the responding, supporting the notion that cannabinoids may serve as a positive reinforcer in laboratory animals. Nevertheless, significant differences among strains and responding modalities were observed in the percentage of acquisition, amount of drug intake during maintenance and timing of extinction. In addition, no significant strain differences were found in motor response to WIN 55,212-2 (0.3 and 3.0 mg/kg), thus excluding that strain differences observed during cannabinoid self-administration could be related to different cannabinoid-induced locomotor effects.     

A novel computerized functional assessment for human immunodeficiency virus-associated neurocognitive disorder

Human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) is present in 30–60 % of HIV-positive (HIV+) individuals and can be assessed by neuropsychological testing and level of functional impairment. HAND diagnosis therefore requires accurate assessment of functional impairment. The Computer Assessment of Mild Cognitive Impairment (CAMCI) is a computer-based screening tool that includes performance-based measures of functional impairment. We sought to evaluate the CAMCI as a functional assessment tool in HAND. One hundred fourteen HIV+ patients and 38 HIV-negative (HIV?) patients underwent neuropsychological and CAMCI testing. Cognitive status for HIV+ subjects was classified using the Frascati criteria. HIV+ subjects grouped together and classified by cognitive impairment performed worse than HIV? subjects on several of the CAMCI tasks, including following directions to the supermarket (p?=?0.05, p?=?0.03), recalling which items to purchase (p?=?0.01, p?=?0.02), and remembering to stop at a supermarket (p?<?0.01, p?=?0.01) and the post office (p?<?0.01, p?=?0.03). After controlling for hepatitis C status and depression symptomatology, the tasks “following directions to the supermarket” and the “recalling which items to purchase” were no longer significant. The “remembering to run two separate errands” tasks retained their significance (p?<?0.01 for both tasks). A subset of the CAMCI tasks therefore successfully differentiated HIV+ patients from HIV? individuals. Differences in hepatitis C status and depression symptomatology could account for some of the function assessment differences in the CAMCI. These results suggest the CAMCI could be a useful objective performance-based functional assessment in patients with HIV.