A comparative evaluation of four DNA extraction protocols from whole blood sample.

All organisms have Deoxyribonucleic acid (DNA) within their cells. DNA is a complex molecule that contains all of the information necessary to build and maintain an organism. DNA extraction is one of the most basic and essential techniques in the study of DNA that allow huge advances in molecular biology, biotechnology and bioinformatics laboratories. Whole blood samples are one of the main sources used to obtain DNA and there are many different protocols available in this issue. In current research, compared four DNA extraction protocols from blood samples; include modified phenol-chloroform protocol, two salting-out and enzyme free method and from commercial kit. The extracted DNAs by these protocols were analyzed according to their time demands, quality and quantity, toxicity and functionality in PCR method. Also the quality and quantity of the extracted DNA were surveyed by gel electrophoresis and Nanodrop spectrophotometry methods. It was observed that there are not significantly differences between these methods about DNA Purity (A260/A280), but the DNA yield (ng DNA/µl) of phenol/chloroform method was higher than other methods. In addition, phenol/chloroform was the most toxic method and it takes more time than other methods. Roche diagnostics GmbH kit was the most expensive among the four methods but the least extraction time was required and it was the safest method.

Concentration Field Evolution during the Drying of a Thin Polymer Solution Film near the Contact Line.

An experimental study is performed for polymer concentration field measurements during the drying of an aqueous poly(vinyl alcohol) solution inside a shallow cavity near a vertical side wall. The measurements are based on optical techniques such as 3D confocal microscopy for laser-induced fluorescence analysis. The results reveal a significant concentration heterogeneity across the film near the meniscus during the drying process. The concentration at the solution-air interface remains higher compared to the bulk, and it increases toward the pinned contact line and also over time. A skin layer starts forming as the surface concentration reaches the glass-transition concentration, after which the evaporation rate starts decreasing. Regardless of the cavity depth and the initial polymer concentration, the drying film undergoes a similar concentration evolution during the evaporation process, although minor differences can be recognized. For instance, a low local capillary number at the surface is associated with a wavy surface concentration profile while at higher capillary numbers disturbances are damped and a much more uniform concentration profile is observed.

Involvement of adrenergic and cholinergic systems in nicotine-induced anxiogenesis in mice.

In the present study, the effect of alpha-adrenoceptor agents on response to nicotine in an anxiety model (elevated plus-maze) in mice was investigated. Administered nicotine reduced indices of anti-anxiety behaviour (percent open-arm time (%open-arm time) and percent open-arm entries (%open-arm entry)) and increased indices of anxiety behaviour (protected stretched attention posture and percent of protected head dipping (%protected dipping)), indicating that nicotine elicits an anxiogenic response. This response to the drug was obtained 7 min but not 30 min after drug injection and with doses of 0.25 and 0.5 mg/kg. Nicotinic receptor antagonists mecamylamine (0.5 and 1 mg/kg) and hexamethonium (5 and 10 mg/kg) reduced the response induced by nicotine (0.25 mg/kg). Mecamylamine (1 mg/kg; decreased %open-arm entry and increased protected stretched attention posture) and hexamethonium (10 mg/kg; decreased %open-arm time) showed an anxiogenic-like profile. A muscarinic receptor antagonist, atropine (2.5 and 5 mg/kg), did not alter the nicotine response but elicited an anxiogenic effect by itself. The alpha(1)-adrenoceptor antagonist prazosin (0.25 and 0.5 mg/kg), but not the alpha(1)-adrenoceptor agonist, phenylephrine (4 and 6 mg/kg), reversed the nicotine effect. Single administration of phenylephrine (6 mg/kg) increased %open-arm time, while prazosin did not alter the anxiety behaviour. The alpha(2)-adrenoceptor agonist clonidine (0.001 and 0.01 mg/kg), induced complete immobility when administered in combination with nicotine. However, an alpha(2)-adrenoceptor antagonist, yohimbine (0.5 and 1 mg/kg), appeared to reverse the nicotine response, but did not show interaction with nicotine's effect. Clonidine did not elicit any effect, but yohimbine (1 mg/kg) increased %open-arm entry and %open-arm time by itself. It can be concluded that certain doses of nicotine (0.25 and 0.5 mg/kg) 7 min after their injection induce an anxiogenic effect through nicotinic mechanism(s), and that involvement of alpha(1)- but not alpha(2)-adrenoceptors in the response to nicotine seems likely.

Brain structure and function and the outcomes of treatment for depression.

BACKGROUND: Depressed patients have a variety of brain structural alterations, the most common being atrophy and deep white-matter lesions. Alterations in brain function also are common, particularly regional decreases in cerebral metabolism and perfusion. METHOD: We review here the evidence that alterations in brain structure and function may explain some of the heterogeneity in outcomes of depression. We also report initial results suggesting that measurement of brain structure and function may help to predict outcomes of treatment for depression. Brain structure was examined using three-dimensional reconstruction and volumetric analysis of magnetic resonance imaging (MRI) scans. Brain function was examined using quantitative electroencephalography (QEEG), performed at baseline and serially during the course of treatment. QEEG measures included coherence (a measure of synchronized activity between brain regions) and cordance (a measure strongly associated with regional cerebral perfusion). RESULTS: Depressed patients have been reported to have larger volumes of white-matter lesions than controls. We have found that some types of white-matter lesions are associated with lower coherence and that subjects with low coherence had significantly poorer outcomes of treatment for depression at 2-year follow-up. Depressed subjects had low cordance at baseline, which decreased further during the course of effective treatment. Subjects who did not improve had little or no change in cordance. Changes in cordance were detected prior to the onset of clinical response, with decreases seen as early as 48 hours after the initiation of treatment in subjects who showed eventual response. CONCLUSION: These preliminary results suggest that functional imaging using QEEG may be useful for assessing, and possibly predicting, outcomes of treatment for depression.