Association of glutathione-S-transferase polymorphisms with atopic dermatitis risk in preschool age children

Background: Glutathione S-transferase (GST) enzymes are critical for detoxifying reactive oxygen species (ROS) and their products which have been implicated in the pathology of inflammatory diseases such as atopic dermatitis (AD). Methods: We investigated the effects of genetic polymorphisms of GST on the risk of AD in preschool age children. Biomarkers for oxidative stress were also evaluated with respect to GST genotype. Results: The GSTP1 Val105 allele was significantly associated with an increased risk of AD [odds ratio (OR)=1.62, p<0.05]. The combination of the GSTP1 Val105 allele and the GSTT1 null genotype further increased this risk by 2.3-fold (p<0.01). No association was observed for the GSTM1 null or GSTT1 null genotype alone. In children with AD, blood total antioxidant capacity was significantly less (p<0.001), while malondialdehyde was higher (p=0.12). Children with the GSTP1 Val105 allele had significantly lower concentrations of erythrocyte glutathione compared to GSTP1 Ile/Ile homozygotes (p=0.03). Conclusions: Our study suggests that the GSTP1 Val105 allele is an important determinant of susceptibility to AD in preschool age children and increased oxidative stress may play a role in the pathogenesis of AD. Clin Chem Lab Med 2009;47:1475–81.Peer Reviewe

Porphyra-334, a mycosporine-like amino acid, attenuates UV-induced apoptosis in HaCaT cells

The main aim of the current research was to study the effect of porphyra-334, one of mycosporine-like amino acids (MAAs), well known as UV-absorbing compounds, on UV-induced apoptosis in human immortalized keratinocyte (HaCaT) cells. Due to their UV-screening capacity and ability to prevent UV-induced DNA damage, MAAs have recently attracted considerable attention in both industry and research in pharmacology. Herein, human HaCaT cells were used to determine the biological activities of porphyra-334 by various in vitro assays, including proliferation, apoptosis and Western blot assays. The proliferation rate of UV-irradiated HaCaT cells was significantly decreased compared to the control group. Pretreatment with porphyra-334 markedly attenuated the inhibitory effect of UV and induced a dramatic decrease in the apoptotic rate. Expression of active caspase-3 protein was increased in response to UV irradiation, while caspase-3 levels were similar between cells treated with porphyra-334 and the non-irradiated control group. Taken together, our data suggest that porphyra-334 inhibits UV-induced apoptosis in HaCaT cells through attenuation of the caspase pathway

A study on the tuning parameter of continuous variable valve for reverse continuous damper

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.Semi-active suspension systems are greatly expected to be in the mainstream of future controlled suspensions for passenger cars. In this study, a continuous variable damper for a passenger car suspension is developed, which is controlled actively and exhibits high performance with light weight, low cost, and low energy consumption. To get a fast response of the damper, a reverse damping mechanism is adapted, and to get small pressure change rate after blow-off, a pilot controlled proportional valve is designed and analyzed. The reverse continuous variable damper is designed as a HS-SH damper which offers good body control with reduced transferred input force from the tire, compared with any other type of suspension system. The damper structure is designed, so that rebound and compression damping forces can be tuned independently, of which the variable valve is placed externally. The rate of pressure change with respect to the flow rate after blow-off becomes smooth when the fixed orifice size increases, which means that the blow-off slope is controllable using the fixed orifice size. Damping forces are measured with the change of the solenoid current at the different piston velocities to confirm the maximum hysteresis of 20 N, linearity, and variance of damping force. The damping force variance is wide and continuous, and is controlled by the spool opening, of which scheme is usually adapted in proportional valves. The reverse continuous variable damper developed in this study is expected to be utilized in the semi-active suspension systems in passenger cars after its performance and simplicity of the design is confirmed through a real car test

Evaluation of the pathogenicity of GJB3 and GJB6 variants associated with nonsyndromic hearing loss

AbstractA number of genes responsible for hearing loss are related to ion recycling and homeostasis in the inner ear. Connexins (Cx26 encoded by GJB2, Cx31 encoded by GJB3 and Cx30 encoded by GJB6) are core components of gap junctions in the inner ear. Gap junctions are intercellular communication channels and important factors that are associated with hearing loss. To date, a molecular genetics study of GJB3 and GJB6 as a causative gene for hearing loss has not been performed in Korea. This study was therefore performed to elucidate the genetic characteristics of Korean patients with nonsyndromic sensorineural hearing loss and to determine the pathological mechanism of hearing loss by analyzing the intercellular communication function of Cx30 and Cx31 variants. Sequencing analysis of the GJB3 and GJB6 genes in our population revealed a total of nine variants, including four novel variants in the two genes. Three of the novel variants (Cx31-p.V27M, Cx31-p.V43M and Cx-30-p.I248V) and two previously reported variants (Cx31-p.V84I and Cx30-p.A40V) were selected for functional studies using a pathogenicity prediction program and assessed for whether the mutations were located in a conserved region of the protein. The results of biochemical and ionic coupling tests showed that both the Cx31-p.V27M and Cx31-p.V84I variants did not function normally when each was expressed as a heterozygote with the wild-type Cx31. This study demonstrated that two variants of Cx31 were pathogenic mutations with deleterious effect. This information will be valuable in understanding the pathogenic role of GJB3 and GJB6 mutations associated with hearing loss

Prediction for serious bacterial infection in febrile children aged 3 years or younger: comparison of inflammatory markers, the Laboratory-score, and a new laboratory combined model

Purpose To compare the efficacy of inflammatory markers, the Laboratory-score, and a new laboratory combined model for predicting serious bacterial infection (SBI) in young febrile children. Methods The presence of SBI was reviewed in previously healthy children aged 3 years or younger with fever (> 38℃) who visited the emergency department from 2017 through 2018. Areas under the curves (AUCs) of the receiver operating characteristic curve for SBI were compared with individual inflammatory markers (white blood cells [WBC] count, erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], procalcitonin [PCT], and urine WBC count), the Laboratory-score, and a laboratory combined model. The latter model was developed using logistic regression analysis including ESR, CRP, and PCT. Results Of the 203 enrolled children, SBI was diagnosed in 58 (28.6%). For SBI prediction, the Laboratory-score showed 51.7% sensitivity (95% confidence interval [CI], 38.2%-65.0%) and 83.5% specificity (95% CI, 76.4%-89.1%). The AUC of the Laboratory-score (0.76) was significantly superior to the values of all individual inflammatory markers (WBC, 0.59 [P = 0.032]; ESR, 0.69; and CRP, 0.74 [P < 0.001]) except that of PCT (0.77, [P < 0.001]). The AUC of the laboratory combined model (0.80) was superior to that of the Laboratory-score (0.76) (P < 0.001). Conclusion In this study, the new laboratory combined model showed good predictability for SBI. This finding suggests the usefulness of combining ESR, CRP, and PCT in predicting SBI