Protection from ultraviolet damage and photocarcinogenesis by vitamin d compounds

© Springer Nature Switzerland AG 2020. Exposure of skin cells to UV radiation results in DNA damage, which if inadequately repaired, may cause mutations. UV-induced DNA damage and reactive oxygen and nitrogen species also cause local and systemic suppression of the adaptive immune system. Together, these changes underpin the development of skin tumours. The hormone derived from vitamin D, calcitriol (1,25-dihydroxyvitamin D3) and other related compounds, working via the vitamin D receptor and at least in part through endoplasmic reticulum protein 57 (ERp57), reduce cyclobutane pyrimidine dimers and oxidative DNA damage in keratinocytes and other skin cell types after UV. Calcitriol and related compounds enhance DNA repair in keratinocytes, in part through decreased reactive oxygen species, increased p53 expression and/or activation, increased repair proteins and increased energy availability in the cell when calcitriol is present after UV exposure. There is mitochondrial damage in keratinocytes after UV. In the presence of calcitriol, but not vehicle, glycolysis is increased after UV, along with increased energy-conserving autophagy and changes consistent with enhanced mitophagy. Reduced DNA damage and reduced ROS/RNS should help reduce UV-induced immune suppression. Reduced UV immune suppression is observed after topical treatment with calcitriol and related compounds in hairless mice. These protective effects of calcitriol and related compounds presumably contribute to the observed reduction in skin tumour formation in mice after chronic exposure to UV followed by topical post-irradiation treatment with calcitriol and some, though not all, related compounds

The effect of various conductivity and viscosity models considering Brownian motion on nanofluids mixed convection flow and heat transfer

In this paper the effect of using various models for conductivity and viscosity considering Brownian motion of nanoparticles is investigated. This study is numerically conducted inside a cavity full of Water-Al2O3 nanofluid at the case of mixed convection heat transfer. The effect of some parameters such as the nanoparticle volume fraction, Rayleigh, Richardson and Reynolds numbers has been examined. The governing equations with specified boundary conditions has been solved using finite volume method. A computer code has been prepared for this purpose. The results are presented in form of stream functions, isotherms, Nusselt number and the flow power with and without the Brownian motion taken into consideration. The results show that for all the applied models the stream functions and isotherm have approximately same patterns and no considerable difference has been observed. In all the studied models when considering the Brownian motion, the average Nusselt number is higher than not taking this effect into account. The models of Koo-Kleinstreuer and Li-Kleinstreuer give almost same values for the maximum stream function and average Nusselt number. It is also true about the models of Vajjha-Das and Xiao et al

The comparison of Friedwald formula and direct measurement to determine the serum levels of LDL-C

Background and Objective: The risk of coronary heart disease (CHD) is proportional to the LDL-C lipoprotein. Due to frequent use of Friedwald formula in estimation of LDL-C in most laboratories, this study was done to compare the Friedwald formula and direct measurement to determine the serum levels of LDL-C Materials and Methods: This descriptive study was conducted on of 598 patients 226 male and 372 female whome referred to Imam Ali hospital Andimeshk cityin Khozestan province of Iran for health check up during 2009. 5 ml of the venous blood was drown. Total cholesterol (TC) (mg/dl), Triglyceride (TG) (mg/dl), HDL-C (mg/dl) and LDL-C (mg/dl) of serum are measured with Pars azmun company kits. The Friedwald formula was used for estimation of LDL-C. The K=3, 3.5 and 5 were used to stimate the lipid by Friedwald formula. Data were analyzed using SPSS-18, Pearson correlation coefficient and ANOVA tests. Results: A total of 598 serum samples collected 37.8% were men and 62.2% women. The mean age of participants was 38.8±10.77 years. Minimum age 21 years and maximum age was 77 years. Mean deviation for TG≤150, 201-300 and 301-400 in Friedwald formula (k=5) were -13.01±8.79, -17.11±13.17 and -18.63±18.54, respectively and with k=3 are -.39±12.04, -0.078±18.55 and 0.04±25.55 and for TG between 151-200 is -9.72±10.54 and with k=3.5 is equal to 0.82±13.70. Pearson correlation test showed that direct measurment and calculated from the equation Friedwald, for triglycerides in the area equal to or less than 150, 151-200, 201-300 and 301-400 mg/dl, with correlated to Pearson correlation coefficient were 0.982, 0.991, 0.991 and 0.975, respectively. Conclusion: This study showed that the direct measurement method is superior to the Friedwald equation, otherwise, equation Friedwald formula with K=3 is recommended

Cross-Diagnosis Structural Correlates of Autistic-Like Social Communication Differences

Social communication differences are seen in autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and obsessive-compulsive disorder (OCD), but the brain mechanisms contributing to these differences remain largely unknown. To address this gap, we used a data-driven and diagnosis-agnostic approach to discover brain correlates of social communication differences in ASD, ADHD, and OCD, and subgroups of individuals who share similar patterns of brain-behavior associations. A machine learning pipeline (regression clustering) was used to discover the pattern of association between structural brain measures (volume, surface area, and cortical thickness) and social communication abilities. Participants (n = 416) included children with a diagnosis of ASD (n = 192, age = 12.0[5.6], 19% female), ADHD (n = 109, age = 11.1[4.1], 18% female), or OCD (n = 50, age = 12.3[4.2], 42% female), and typically developing controls (n = 65, age = 11.6[7.1], 48% female). The analyses revealed (1) associations with social communication abilities in distributed cortical and subcortical networks implicated in social behaviors, language, attention, memory, and executive functions, and (2) three data-driven, diagnosis-agnostic subgroups based on the patterns of association in the above networks. Our results suggest that different brain networks may contribute to social communication differences in subgroups that are not diagnosis-specific