A Multiplex PCR Approach for Detecting Dual Infections and Recombinants Involving Major HIV Variants

The cocirculation of different HIV types and groups can lead to dual infections and recombinants, which hinder diagnosis and therapeutic management. We designed two multiplex PCRs (mPCRs) coupled with capillary electrophoresis to facilitate the detection of such infections. The first, M_MO2, targets three variants (HIV-1/M, HIV-1/O, and HIV-2), and the second, M_MO, targets HIV-1/M and HIV-1/O. These mPCRs were validated on DNA and RNA extracts from 19 HIV-1/M, 12 HIV-1/O, and 13 HIV-2 cultures and from mixtures simulating dual infections. They were then assessed with DNA and RNA extracts from samples of 47 clinical monoinfections and HIV-1/M+O dual infections or infections with HIV-1/MO recombinants. Both mPCRs had excellent specificity. Sensitivities ranged from 80 to 100% for in vitro samples and from 58 to 100% for clinical samples, with the results obtained depending on the material used and the region of the genome concerned. Sensitivity was generally lower for DNA than for RNA and for amplifications of the integrase and matrix regions. In terms of global detection (at least one target gene for each strain), both mPCRs yielded a detection rate of 100% for in vitro samples. M_MO2 detected 100% of the clinical strains from DNA and 97% from RNA, whereas M_MO detected 100% of the strains from both materials. Thus, for in vitro and clinical samples, M_MO2 was a useful tool for detecting dual infections with HIV-1 and HIV-2 (referred to as HIV-1+HIV-2) and HIV-1/M+O, and M_MO was useful for detecting both MO dual infections and MO mosaic patterns.     

Apathy in aging: Are lack of interest and lack of initiative dissociable?

Apathy is common in aging and generally defined on the basis of three dimensions: lack of initiative, lack of interest and emotional blunting. Curiously, no study until now has examined the associations and dissociations between these dimensions in elderly people (with or without dementia). These questions were addressed in two studies. In the first study, we explored the distribution of scores and the relationships between the three dimensions of apathy in 56 patients with dementia, focusing mainly on lack of initiative and lack of interest. Apathy was hetero-evaluated with the Apathy Inventory (AI), a scale widely used to assess the apathy dimensions in aging. In the second study, given the AI's limitations, we investigated in more detail the relationship between lack of initiative and interest in 115 elderly people using a new questionnaire specifically designed to assess these two dimensions. Results showed that lack of initiative was closely related to lack of interest (Study 1). Although we used a more specific questionnaire, these facets of apathy did not constitute two separable dimensions, but reflected a common main factor of apathy in aging (Study 2). Thus, the distinction between lack of initiative and lack of interest seems questionable. Only a multifactorial approach that includes the various psychological factors involved in apathy would enable one to gain a better understanding of the different manifestations of apathy and to highlight possible dissociations between them.     

Is the potent 5-HT1A receptor agonist, alnespirone (S-20499), affecting dopaminergic systems in the rat brain?

The effects of the new methoxy-chroman 5-HT_1A receptor agonist, alnespirone (S-20499), on the dopamine systems in the rat brain were assessed in vivo by means of electrophysiological and neurochemical techniques. Cumulative doses of alnespirone (0.032–4.1 mg kg⁻¹, i.v.) did not modify the spontaneous firing rate of dopamine neurons in the substantia nigra as well as in the ventral tegmental area. The local application of alnespirone (0.1–10 μM) by reverse microdialysis into the dorsal striatum did not affect the dopamine output but induced a moderate, although dose-independent, increase of 5-HT (5-hydroxytryptamine, serotonin) concentrations in the dialysate. As expected of a 5-HT_1A receptor agonist, intraperitoneal (i.p.) administration of alnespirone at 2–32 mg kg⁻¹ markedly decreased 5-HT turnover in the striatum. Parallel measurements of dopamine turnover showed that alnespirone exerted no effect except at the highest dose (32 mg kg⁻¹, i.p.) for which a significant increase was observed. Interestingly, both alnespirone-induced reduction in 5-HT turnover and increase in dopamine turnover could be prevented by pretreatment with the selective 5-HT_1A receptor antagonist WAY-100635 (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]–N-(2-pyridinyl)cyclohexane carboxamide). Altogether, these data indicate that alnespirone does not exert any direct influence on central dopamine systems. The enhanced dopamine turnover due to alnespirone at high dose appeared to result from 5-HT_1A receptor stimulation, further supporting the idea that this receptor type may play a key role in 5-HT-dopamine interactions in brain.     

Modification of isotactic poly(propylene) with a nitrogen plasma; differences in comparison to the treatment with a carbon dioxide plasma

The modification of isotactic poly(propylene) by nitrogen plasma treatment was studied in comparison to the use of a carbon dioxide plasma, which was reported earlier. The effect of the modification was characterized with secondary ion mass spectrometry (SIMS) to a depth of 3 Å, with electronic spectroscopy for chemical analysis (ESCA) to a depth of 20 Å and with attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to a depth of 10 μm: the nitrogen plasma modification seems to be milder than the CO₂ plasma treatment. Surface degradation is a minor reaction, and in an opposite manner, crosslinking and functionalization (formation of primary amino groups) are the most important reactions. Radicals, probably originating from the elimination of [methyl groups] along the polymer backbone, could induce these reactions.