Dark-adapted red flash ERGs in healthy adults

Purpose: The x-wave of the dark-adapted (DA) ERG to a red flash reflects DA cone function. This exploratory study of healthy adults aimed to investigate changes in the DA red ERG with flash strength and during dark adaptation to optimise visualisation and therefore quantification of the x-wave. Methods: The effect of altering red flash strength was investigated in four subjects by recording ERGs after 20 minutes dark adaptation to red flashes (0.2–2.0 cd s m-2) using skin electrodes and natural pupils. The effect of dark adaptation duration was investigated in 16 subjects during 20 minutes in the dark, by recording DA 1.5 red ERGs at 1, 2, 3, 4, 5, 10, 15 and 20 minutes. Results: For a dark adaption period of 20 minutes, the x-wave was more clearly visualised to weaker (< 0.6 cd s m-2) red flash strengths: to stronger flashes it became obscured by the b-wave. For red flashes of 1.5 cd s m-2, the x-wave was most prominent in ERGs recorded after 1–5 minutes of dark adaptation: with longer dark-adaptation, it was subsumed into the b-wave’s rising edge. Conclusions: This small study suggests that x-wave visibility in healthy subjects after 20 minutes dark adaptation is improved by using flashes weaker than around 0.6 cd s m-2; for flash strengths of 1.5 cd s m-2, x-wave visibility is enhanced by recording after only around 5 minutes of dark adaptation. No evidence was found that interim red flash ERGs affecting the dark-adapted state of the normal retina

Comparative study of cytotoxicity of ferromagnetic nanoparticles and magnetitecontaining polyelectrolyte microcapsules

The work was supported by Ministry of Education and Science of the Russian Federation as part of the State task for National Research Mordovia State University, project No. 2952 and the Government of the Russian Federation (grant №14.Z50.31.0004 to support scientific research projects implemented under the supervision of leading scientists

Genetic variation in vitamin D-related genes and risk of colorectal cancer in African Americans

PurposeDisparities in both colorectal cancer (CRC) incidence and survival impact African Americans (AAs) more than other US ethnic groups. Because vitamin D is thought to protect against CRC and AAs have lower serum vitamin D levels, genetic variants that modulate the levels of active hormone in the tissues could explain some of the cancer health disparity. Consequently, we hypothesized that genetic variants in vitamin D-related genes are associated with CRC risk.MethodsTo test this hypothesis, we studied 39 potentially functional single-nucleotide polymorphisms (SNPs) in eight genes (CYP2R1, CYP3A4, CYP24A1, CYP27A1, CYP27B1, GC, DHCR7, and VDR) in 961 AA CRC cases and 838 healthy AA controls from Chicago and North Carolina. We tested whether SNPs are associated with CRC incidence using logistic regression models to calculate p values, odds ratios, and 95% confidence intervals. In the logistic regression, we used a log-additive genetic model and used age, gender, and percent West African ancestry, which we estimated with the program STRUCTURE, as covariates in the models.ResultsA nominally significant association was detected between CRC and the SNP rs12794714 in the vitamin D 25-hydroxylase gene CYP2R1 (p=0.019), a SNP that has previously been associated with serum vitamin D levels. Two SNPs, rs16847024 in the GC gene and rs6022990 in the CYP24A1 gene, were nominally associated with left-sided CRC (p=0.015 and p=0.018, respectively).ConclusionsOur results strongly suggest that genetic variation in vitamin D-related genes could affect CRC susceptibility in AAs. Electronic supplementary materialThe online version of this article (doi:10.1007/s10552-014-0361-y) contains supplementary material, which is available to authorized users

Kings ransom. t.V

104 tr. ; 21 cm

The Application of Modified Flow-Through Cell Apparatus for the Assessment of Chlorhexidine Dihydrochloride Release from Lozenges Containing Sorbitol

The objective of this work was to apply a new apparatus for the assay of the drug release from lozenge tablet with a potential use in the treatment of oral candidosis and another conditions connected to microbial etiopathology in the oral cavity or as an antiplaque factor. Also, an approach to comparison of the applied method with the classical paddle apparatus method was performed. Tablets containing chlorhexidine dihydrochloride were formulated with granulated sorbitol of different grades (diameter of 110, 180, 480, and 650 μm, respectively), lactose, and magnesium stearate as excipients. Tablets were obtained through direct compression, and uniformity of weight, friability, breaking strength, disintegration, and release rate were evaluated. The disintegration times ranged between 10 and 21 min. In the next stage of the study, the release of chlorhexidine from lozenges prepared with granulated sorbitol grade 110 μm and different amounts of lactose and magnesium stearate was assessed. Two stages were observed during the release of chlorhexidine dihydrochloride from the lozenges, assayed by the classical paddle apparatus method II USP. In the first stage, release rates were between 2.6 × 10−2 and 4.7 × 10−2 min−1, in the second stage between 1.7 × 10−3 and 7.7 × 10−3 min−1. In the case of the in-house method, the release was near to first-order kinetics through the entire release experiment, with rate constants between 3.6 × 10−2 and 6.6 × 10−2 min−1. The sorbitol granulate of granules with diameter 110 μm was found to be most suitable for the lozenges with chlorhexidine dihydrochloride and lactose. The in-house release method, proposed in this work, seems to be more realistic for the preliminary assessment of predicted drug concentrations in the oral cavity after the intake of a lozenge