Acute effect of 17 beta-estradiol and lithium on ovariectomized rat brain biogenic amines metabolism

The effect of 17 beta-estradiol (E2) on the response of dopamine (DA) and serotonin (5-HT) to acute lithium in the brains of ovariectomized rats was investigated. An E2 injection (100 ng/s.c.) to ovariectomized rats did not change striatal DA levels, whereas the levels of its metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), increased 30 min later; concentrations of 5-HT and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), also remained unchanged. In the frontal cortex, DA, 5-HT, HVA and 5-HIAA levels remained unchanged after the E2 injection, whereas DOPAC levels and DOPAC/DA and HVA/DA ratios increased 30 min later. Injection of LiCl (10 mEq) decreased striatal DA levels, increased DOPAC levels and slightly decreased HVA levels; by contrast, frontal cortex DA and HVA levels increased but DOPAC levels were unchanged. A biphasic response of striatal 5-HT levels occurred, increasing shortly after injection of LiCl, followed by a decrease; 5-HIAA levels, however, increased. In the frontal cortex, injection of rats with LiCl led to a gradual increase in 5-HT levels, whereas 5-HIAA concentrations decreased. In the presence of E2, LiCl effected a greater decrease in striatal DA than injection of LiCl alone, advanced the DOPAC peak by 30 min and increased HVA levels; E2 had less effect on the 5-HT response to LiCl, except the decreases in 5-HT and 5-HIAA at 60 min were greater. Furthermore, in the striatum, the increased DA turnover caused by LiCl, estimated by the DOPAC/DA and HVA/DA ratios, was advanced in rats treated with E2. In the presence of E2, LiCl slightly increased frontal cortex DA, DOPAC and HVA levels compared with treatment with LiCl alone, whereas DOPAC levels decreased in rats treated with LiCl + E2 compared with levels in E2-treated rats. Generally, higher levels of 5-HT and 5-HIAA were measured in the frontal cortices of rats treated with LiCl + Ex compared with rats injected with LiCl. These results indicate that E2 potentiates the acute effect of lithium on striatal and frontal cortex DA and 5-HT levels and metabolism, suggesting a role of the hormonal state on this drug response.     

Tie-Over Bolster Pressure Dressing Improves Outcomes of Skin Substitutes Xenografts on Athymic Mice

The efficacy of skin substitutes is established for the treatment of burn injuries, but its use is not limited to this condition. This technology has the potential to improve the treatment of various conditions by offering highly advanced and personalized treatments. In vivo studies are challenging but essential to move to clinical use in humans. Mice are the most widely used species in preclinical studies, but the main drawback of this model is the limited surface area of the graft in long-term transplantation studies caused by the displacement and the contraction of the graft. We improved the conventional surgical procedures by stabilizing the chamber covering the graft with intramuscular sutures and by adding a tie-over bolster dressing. The current study was therefore performed to compare outcomes of skin grafts between the conventional and optimized skin graft model. Human self-assembled skin substitutes (SASSs) were prepared and grafted to athymic mice either by the conventional method or by the new grafting method. Graft healing and complications were assessed using digital photographs on postoperative days 7, 14, and 21. Similar structure and organization were observed by histological staining. The new grafting method reduced medium and large displacement events by 1.26-fold and medium and large contraction events by 1.8-fold, leading to a 1.6-fold increase in graft surface area compared to skin substitutes grafted with the usual method. This innovation ensures better reproducibility and consistency of skin substitute transplants on mice.     

Chemorheology of Aqueous-Based Alumina-Poly(vinyl alcohol) Gelcasting Suspensions

A new gelcasting system based on aqueous-based alumina-poly(vinyl alcohol) (PVA) suspensions cross-linked by an organotitanate coupling agent has been developed. The chemorheological properties of this system exhibited a strong compositional dependence. A sol-gel phase diagram was established, which yielded the critical titanium concentration ([Ti]_c) required for gelation at a given PVA volume fraction as well as the minimum PVA volume fraction (φ^min_PVA= 0.0245) and titanium concentration ([Ti]_min= 9.984 × 10^-4 g of Ti/mL) below which gelation was not observed irrespective of solution composition. The gelation time of suspensions of constant PVA volume fraction (φ^soln_PVA) decreased with increased cross-linking agent concentration, temperature, and solids volume fraction. The steady-state viscosity and elastic modulus of polymer solutions (φ^soln_PVA= 0.05) of varying [Ti] were well described by the percolation model, giving scaling exponents of 0.84 and 1.79, respectively. The steady-state elastic modulus of gelcasting suspensions, which provided a measure of their handling strength in the as-gelled state, increased with increased solids volume fraction.     

Useful Signaling Waveforms and Related Transmit Filter Functions in Bandwidth Limited Channels

A collection of easily generated signaling waveforms for a binary baseband data system is presented along with the required transmit filter functions. Filtering is based on the criterion of zero intersymbol interference and optimum Peversus receiver input signal-to-noise ratio. The channel considered is a linear one of bandwidth equal to[(1 + alpha)/2]Hz/baud; α being allowed to vary between zero and one. The results apply, as well, to multilevel data and to bandpass systems, such as digital radio.     

Middle school students and bicycle helmet use: knowledge, attitudes, beliefs, and behaviors

Previous research has shown that bicycle helmet use among older children and adolescents continues to be low. This study determined middle school students' knowledge, attitudes, beliefs, and behaviors related to bicycle helmet use. Six middle schools in Hillsborough County, Fla., served as the research settings. A pretested survey instrument was administered to students. Overall, 3,333 sixth and seventh graders responded. Results showed that most children owned a bicycle, 38.1% owned a helmet, but only 15.8% wore a helmet the last time they rode a bike. Many students (49.7%) did not know or did not believe there was a bicycle helmet law in Florida. Predictors of helmet use were intention to use a helmet the next time one rides a bike, having a helmet, siblings' use of helmets, and friends' use of helmets.     

Investigation of the Fuzzy Complex between RSV Nucleoprotein and Phosphoprotein to Optimize an Inhibition Assay by Fluorescence Polarization

The interaction between Respiratory Syncytial Virus phosphoprotein P and nucleoprotein N is essential for the formation of the holo RSV polymerase that carries out replication. In vitro screening of antivirals targeting the N-P protein interaction requires a molecular interaction model, ideally consisting of a complex between N protein and a short peptide corresponding to the C-terminal tail of the P protein. However, the flexibility of C-terminal P peptides as well as their phosphorylation status play a role in binding and may bias the outcome of an inhibition assay. We therefore investigated binding affinities and dynamics of this interaction by testing two N protein constructs and P peptides of different lengths and composition, using nuclear magnetic resonance and fluorescence polarization (FP). We show that, although the last C-terminal Phe₂₄₁ residue is the main determinant for anchoring P to N, only longer peptides afford sub-micromolar affinity, despite increasing mobility towards the N-terminus. We investigated competitive binding by peptides and small compounds, including molecules used as fluorescent labels in FP. Based on these results, we draw optimized parameters for a robust RSV N-P inhibition assay and validated this assay with the M76 molecule, which displays antiviral properties, for further screening of chemical libraries.     

Efficacité d'une intervention de groupe auprès d'hommes agressés sexuellement dans leur enfance.

The purpose of this research was to evaluate the effects of a group intervention intended for men victims of childhood sexual abuse (CSA). A quasi-experimental design was used to compare 23 men who took part in the group intervention against 13 men who suffered CSA but who received no service relative to this victimization. Data was collected through a self-administered questionnaire, which comprised various sections, including: 1) one on the participants' sociodemographic and CSA characteristics; 2) a posttraumatic stress symptoms scale; 3) a psychological distress index; 4) a self-esteem measure; and 5) a measure of the feeling of loneliness. The results demonstrate that, compared with the men in the control group, the men who completed the group intervention improved significantly in terms of self-esteem and on the subscale measuring CSA-related traumatic symptoms. No inter-group difference emerged concerning psychological distress, posttraumatic stress, and feeling of loneliness. Despite certain methodological limitations (including the non-random distribution of subjects into groups and the small size of the samples), the use of a quasi-experimental control-group design and of validated standardized measures (including one for posttraumatic stress disorder) lends strength and credence to the study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Direct-Write Fabrication of Integrated, Multilayer Ceramic Components

The need for advanced electronic ceramic components with smaller size, greater functionality and enhanced reliability requires the ability to integrate electronic ceramics in complex 3-D architectures. However, traditional tape casting and screen printing approaches are poorly suited to the requirements of rapid prototyping and small-lot manufacturing. To address this need, a direct-write approach for fabricating highly integrated, multilayer components using a Micropen to deposit slurries in precise patterns is being developed at Sandia. This approach provides the ability to fabricate multifunctional, multimaterial integrated ceramic components (MMICCs) in an agile and rapid way. Commercial ceramic thick-film pastes can be used directly in the system, as can polymer thick-film pastes (PTF). The quality of printed components depends on both the rheology and drying behavior of the pastes. Pastes with highly volatile solvents are inappropriate for the Micropen. This system has been used to make integrated passive devices such as RC filters, inductors, and voltage transformers.