Chronic Voluntary Alcohol Consumption Alters Promoter Methylation and Expression of Fgf-2 and Fgfr1.

Alcohol abuse accounts for 3.3 million deaths annually, rendering it a global health issue. Recently, fibroblast growth factor 2 (FGF-2) and its target, fibroblast growth factor receptor 1 (FGFR1), were discovered to positively regulate alcohol-drinking behaviors in mice. We tested whether alcohol intake and withdrawal alter DNA methylation of Fgf-2 and Fgfr1 and if there is a correlation regarding mRNA expression of these genes. Blood and brain tissues of mice receiving alcohol intermittently over a six-week period were analyzed using direct bisulfite sequencing and qRT-PCR analysis. Assessment of Fgf-2 and Fgfr1 promoter methylation revealed changes in the methylation of cytosines in the alcohol group compared with the control group. Moreover, we showed that the altered cytosines coincided with binding motives of several transcription factors. We also found that Fgf-2 and Fgfr1 gene expression was significantly decreased in alcohol-receiving mice compared with control littermates, and that this effect was specifically detected in the dorsomedial striatum, a brain region involved in the circuitry of the reward system. Overall, our data showed alcohol-induced alterations in both mRNA expression and methylation pattern of Fgf-2 and Fgfr1. Furthermore, these alterations showed a reward system regional specificity, therefore, resembling potential targets for future pharmacological interventions.

A small step for rats alters spatial behavior: rats on a bi-level arena explore each level separately.

We tested rats on a 'bi-level open-field' whose two halves were separated vertically by an 8-cm step that the rats could easily ascend/descend. We sought to determine what might be the factors that shape traveling in three-dimensional environments; what makes an environment perceived as multileveled; and how are multileveled environments explored compared to two-dimensional environments? We found that rats on the bi-level open-field traveled a greater distance on the lower level compared to the upper one. They also spent a long time at the foot of the step before ascending to the upper level. They established a home-base on one level and a local base on the other one, and explored each level separately. We could not find a particular factor that accounted for the preference for the lower level. We suggest that the momentary egocentric sensation of moving vertically, together with an overall area large enough for exploration, result in perceiving an environment as multilevel. Exploration of such environments is fragmented, and each level is explored relatively independently, as has also been shown in other studies. Regarding the unanswered question of earlier studies concerning what integrates fragmented representations, this is the first study that suggests that in rats, and perhaps also in other rodent species, such integration is achieved by means of home-base behavior, resulting in the establishment of a single comprehensive representation of the multilevel environment.

How do rodents explore a three-dimensional environment? Habitat-dependent and direction-dependent differences.

Many animals are surface-bounded, traveling mostly in two-dimensional (2D) environments. However, those that inhabit structured habitats might also require wayfinding in three-dimensional (3D) environments. Here we forced rodents to ascend or descend when traveling. We tested three species: laboratory rats (a common experimental subject); fat sand rats, which forage while climbing shrubs (representing those used to 3D travel); and Tristram's jirds, which forage in plains (not used to climbing). We examined differences between individuals initially placed on top of the apparatus compared with those placed on its bottom, assuming that this, in addition to the above difference in habitats and motor habits, would influence their spatial behavior. Exploratory activity of top-starting rats and sand rats, but not jirds, differed from bottom starters. Nevertheless, despite the need to continuously ascend or descend, both top- and bottom-starters of the three species displayed the spatio-temporal structure of open-field exploration as previously revealed in a horizontal arena. Specifically, exploration constituted a set of round-trips to a home-base. It is suggested that the preservation of a regular structure of spatial behavior was due to the ability of the tested rodents to mostly maintain a horizontal posture of their head when ascending and descending.

Evaluation of the virtues and pitfalls in an HIV screening algorithm based on two fourth generation assays - A step towards an improved national algorithm.

BACKGROUND: Fourth-generation immunoassays used for HIV screening, simultaneously detect anti-HIV antibodies and HIV-1 P24 antigen, but are prone to false-positive results. Usually, they are followed by highly specific third-generation assay, able to differentiate between HIV-1/2 infections. In Israel, screening algorithm is based on consecutive testing by two fourth-generation assays and confirmation by a third-generation test. OBJECTIVES: To evaluate the performance of this algorithm. STUDY DESIGN: Architect HIV1/2 Combo (Combo) reactive results were tested by Vidas HIV Duo Ultra (VD). Confirmation was by INNO-LIA HIV 1/2 or Geenius assays. Five-year results were retrospectively analyzed. HIV true positives (TPs), acute infected (AI), false-positives (FPs) and HIV negatives, were as defined by the algorithm. RESULTS: 501,338 individuals were screened, of which 956 were TPs, 64 AI and 30 F Ps. Specificity was almost 100% and positive predictive value 97%. VD was negative in 94% of confirmed Combo false-reactive individuals. The Combo results in the first tested sample differed substantially between TPs, AI and FPs, enabling the determination of a cutoff value that distinguished 94% of TPs and AI from FPs. CONCLUSIONS: An algorithm is suggested that will use a single sample collection. HIV negative diagnosis will be based on Combo unreactive or Combo reactive/VD negative results. HIV positive diagnosis will be based on Combo reactive/ VD positive results, given a Combo value above a designated cutoff. Below this cutoff samples will be tested by a molecular assay. Since HIV-2 rarely occurs in Israel, the use of a third-generation confirmation assay should be discussed.

Comparison between Roche and Xpert in HIV-1 RNA quantitation: A high concordance between the two techniques except for a CRF02_AG subtype variant with high viral load titters detected by Roche but undetected by Xpert.

BACKGROUND: HIV-1 viral load (VL) testing is important to predict viral progression and to monitor the response to antiretroviral therapy. New HIV-1 VL tests are continuously introduced to the market. Their performance is usually compared to Abbott and/or Roche HIV-1 VL assays, as reference. The Xpert HIV-1 VL test was recently introduced, but its performance compared to Roche has not been sufficiently studied. OBJECTIVES: To compare the Xpert assay with Roche and to assess its use in the HIV clinical laboratory. STUDY DESIGN: A total of 383 plasma samples of HIV-1 infected patients previously tested by Roche, were retrospectively tested by Xpert to determine concordance between the two assays. Samples included a diversity of HIV-1 subtypes and a wide range of VLs. RESULTS: There was a high concordance between the two assays, except for a CRF02_AG subtype variant with high VL titters, that was detected by Roche but undetected by Xpert. The 5' long terminal repeat gene region of this virus, targeted by the Xpert assay, was amplified and sequenced. A 25 nucleotide insert was identified, but was unmatched to any known sequences of HIV-1. This particular insert, however could not explain the false-negativity by the Xpert assay. CONCLUSIONS: This study underlines the challenge to routine VL testing due to the high genetic diversity of HIV-1. Clinicians should, therefore be advised that a negative VL in cases where the clinical picture does not match the laboratory report, might in fact be, a false-negative result of the VL assay.