Association between cyclooxygenase-2 gene polymorphisms and risk of periodontitis: a meta-analysis involving 5653 individuals

There ?765G > C, ?1195G > A, and 8473T > C polymorphisms in cyclooxygenase-2 (COX-2) gene polymorphisms and periodontitis risk were investigated based on published studies; however, their results could not give a conclusive result. Hence, we performed this meta-analysis of six published studies with eight case–control studies including these three polymorphisms which searched from PubMed and Web of Science up to October 15th, 2013. Odds ratios (ORs) with corresponding 95 % confidence intervals (CIs) were calculated to evaluate the association between the three polymorphisms of COX-2 and periodontitis risk. The results from 2,580 periodontitis patients and 3,073 healthy controls showed that none of ?765G > C, ?1195G > A, or 8473T > C polymorphism was not associated with periodontitis susceptibility [Take ?765G > C for example: OR = 0.94, 95 % CI = (0.57–1.53) for C vs. G; OR = 2.34, 95 % CI = (0.72–7.62) for CC vs. GG; OR = 0.68, 95 % CI = (0.46–1.01) for CG vs. GG; OR = 0.81, 95 % CI = (0.52–1.27) for (CG+GG) vs. GG; OR = 2.57, 95 % CI = (0.80–8.29) for CC vs. (GG+CG)]. In subgroup analyses according to the type of periodontitis and ethnicity for ?765G > C and ?1195G > A, and deviations in Hardy–Weinberg equilibrium for ?765G > C, we only observe a boundary association between ?1195G > A polymorphism and Asian population. However, due to limitations of this meta-analysis, the results should treat with caution and we suggest the further researches should be carried out to verify our results.     

Statin Use and the Risk of Parkinson's Disease: An Updated Meta-Analysis

Introduction

In response to the ongoing debate over the relationship between the use of statins and the risk of Parkinson''s disease (PD), we performed a systematic review and meta-analysis of observational studies to examine their association.

Methods

We conducted a review of the literature using electronic databases supplemented by a manual search to identify potentially relevant case-control or cohort studies. Summary relative risk (RRs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Sensitivity and subgroup analyses were also conducted.

Results

Eleven studies (five case-control and six cohort) with a total of 3,513,209 participants and 21,011 PD cases were included. Statin use was associated with a lower risk of PD, with a summary RR of 0.81 (95% CI 0.71–0.92). Sensitivity analysis demonstrated the robustness of results. Subgroup analyses showed that neither study design nor study region significantly influenced the effect estimates. However, subgroup studies adjusted for age or sex had a greater inverse association than did unadjusted analyses (age-adjusted RR 0.75, 95% CI 0.60–0.95; age-unadjusted RR 0.86, 95% CI 0.75–0.99 and sex-adjusted RR 0.76, 95% CI 0.59–0.98; sex-unadjusted RR 0.85, 95% CI 0.79–0.92).

Conclusions

Results of this systematic review suggest that statin use is associated with a reduced PD risk. However, randomized controlled trials and more observational studies should be performed before strong conclusions are drawn.     

Comparative study of two thioredoxin peroxidases from disk abalone (Haliotis discus discus): cloning, recombinant protein purification, characterization of antioxidant activities and expression analysis

Thioredoxin peroxidase (TPx), also named peroxiredoxin (Prx), is an important peroxidase, which can protect organisms against various oxidative stresses. Two TPxs were isolated from a disk abalone (Haliotis discus discus) cDNA library, named as AbTPx1 and AbTPx2, respectively. AbTPx1 and AbTPx2 consist of 1315 and 1045 bp full-length cDNA with 753 and 597 bp open reading frames encoding 251 and 199 amino acids, respectively. The TPx signature motif 1 (FYPLDFTFVCPTEI) and motif 2 (GEVCPA) were conserved in both AbTPx1 and AbTPx2 amino acid sequences. Purified recombinant abalone TPx fusion proteins catalyzed the reduction of H2O2 and butyl hydroperoxide in peroxidase assays. Furthermore, both AbTPx fusion proteins were shown to protect super-coiled DNA from damage by metal-catalyzed oxidation (MCO) in vitro. Escherichia coli cells transformed with AbTPx1 and AbTPx2 coding sequences in pMAL-c2x showed resistance to H2O2 at 0.8 mM concentration by in vivo H2O2 tolerance assay. AbTPx1 and AbTPx2 mRNA were constitutively expressed in gill, mantle, abductor muscle and digestive tract in a tissue specific manner. Additionally, both TPxs mRNA were up-regulated in gill and digestive tract tissues against H2O2 at 3h post injection. The results indicate that AbTPx1 and AbTPx2 gene expressions are induced by oxidative stress and their respective proteins function in the detoxification of different ROS molecules to maintain efficient antioxidant defense in disk abalone.     

Use of moving aeration membrane bioreactor for the efficient production of tissue type plasminogen activator in serum free medium

A moving aeration-membrane (MAM) bioreactor was employed for the production of 2 μg/mL of tissue type Plasminogen Activator (tPA) in serum free medium from normal human fibroblast cells. This system could maintain high cell density for long periods of steady state conditions in perfusion cultivation. Under normal operating conditions, shear stress was as low as 0.65 dynes/cm² at the agitation speed of 80 rpm. Even though cell density gradually decreased with increasing agitation speed, tPA production increased linearly with increasing shear stress within a moderate range. This culture system allowed production of 2 μg tPA/mL while maintaining a high cell density of 1.0×10⁷ viable cells/mL.