Multiple variants in 5q31.1 are associated with systemic lupus erythematosus susceptibility and subphenotypes in the Han Chinese population

BACKGROUND

A previous study provided evidence for a genetic association between PPP2CA on 5q31.1 and systemic lupus erythematosus (SLE) across multi-ancestral cohorts, but failed to find significant evidence for an association in the Han Chinese population.

OBJECTIVES

To explore the association between this locus and SLE using data from our previously published genome-wide association study (GWAS).

METHODS

Single-nucleotide polymorphisms (SNPs) rs7726414 and rs244689 (near TCF7 and PPP2CA in 5q31.1) were selected as candidate independent associations from a large-scale study in a Han Chinese population consisting of 1047 cases and 1205 controls. Subsequently, 3509 cases and 8246 controls were genotyped in two further replication studies. We then investigated the SNPs' associations with SLE subphenotypes and gene expression in peripheral blood mononuclear cells.

RESULTS

Highly significant associations with SLE in the Han Chinese population were detected for SNPs rs7726414 and rs244689 by combining the genotype data from our previous GWAS and two independent replication cohorts. Further conditional analyses indicated that these two SNPs contribute to disease susceptibility independently. A significant association with SLE, age at diagnosis < 20 years, was found for rs7726414 (P = 0·001). The expression levels of TCF7 and PPP2CA messenger RNA in patients with SLE were significantly decreased compared with those in healthy controls.

CONCLUSIONS

This study found evidence for multiple associations with SLE in 5q31.1 at genome-wide levels of significance for the first time in a Han Chinese population, in a combined genotype dataset. These findings suggest that variants in the 5q31.1 locus not only provide novel insights into the genetic architecture of SLE, but also contribute to the complex subphenotypes of SLE.

[Role of neutrophils in treatment of rats with D-galactosamine-induced acute liver failure with bone marrow mesenchymal stem cells]

Objective: To investigate the therapeutic effect of bone marrow mesenchymal stromal cell (BMSC) transplantation on D-galactosamine-induced acute liver failure in Sprague-Dawley (SD) rats, as well as the mechanism of neutrophils in this process. Methods: A total of 39 male SD rats were divided into control group (8 rats, intraperitoneal injection of isotonic saline), model group (10 rats, intraperitoneal injection of D-galactosamine), solvent group (9 rats, tail vein injection of isotonic saline at 2 hours after intraperitoneal injection of D-galactosamine), and treatment group (12 rats, tail vein injection of MSCs at 2 hours after intraperitoneal injection of D-galactosamine). The rats were sacrificed at 24 hours after the model of D-galactosamine-induced acute liver failure was established, and the blood and liver tissue were harvested. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and total bilirubin (TBil) were measured, and blood analysis was performed to measure the number and percentage of neutrophils in peripheral blood. Immunofluorescence assay was used to measure the expression of the neutrophil marker Ly6g in the liver, the myeloperoxidase (MPO) kit was used to measure the activity of MPO in liver, and RT-PCR was used to measure the mRNA expression of inflammatory cytokines and chemokines in the liver, i.e., tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interferon-γ(IFN-γ), interleukin-10 (IL-10), CXC chemokine ligand 1 (CXCL1), and CXC chemokine ligand 2 (CXCL2). Another 64 male SD rats were randomly divided into groups, and the survival rates of rats in each group were observed for 7 days. The independent samples t-test was used for comparison between any two groups (Levene homogeneity test of variance, and the corrected t-test was used for a P value of < 0.05), and the log-rank test was used for comparison of survival rates between any two groups. Results: At 24 hours after acute liver failure was induced by D-galactosamine in the SD rats, there were significant increases in the liver function parameters (ALT: 2884.1±541.0 U/L vs 45.4±11.0 U/L,P< 0.001; AST: 3634.9±755.9 U/L vs 143.9±23.7 U/L,P< 0.001; TBil: 44.4±8.4μmmol/L vs 0.9±0.2μmmol/L,P< 0.001) and the number and percentage of peripheral blood neutrophils [number: (4.7±1.1)×109 vs (1.4±0.4)×109,P< 0.001; percentage: 44.9%±8.0% vs 18.3%±4.4%,P< 0.001]. A large number of neutrophils aggregated in the liver tissue, and there were significant increases in the MPO activity (4.72±1.09 U/g vs 1.13±0.24 U/g,P< 0.001), inflammatory cytokines, and chemokines. Compared with the model group, the treatment group showed significant improvements in liver function (ALT: 1 823.9±389.2 U/L vs 2 884.1±541.0 U/L,P< 0.001; AST: 2173.0±567.3 U/L vs 3634.9±755.9 U/L,P< 0.001; TBil: 30.9±6.5μmmol/L vs 44.4±8.4μmmol/L,P< 0.001) and survival rate (50% vs 12.5%,P= 0.023). Meanwhile, the treatment group also showed significant reductions in the number and percentage of peripheral blood neutrophils [number: (3.5±1.0)×109 vs (4.7±1.1)×109,P= 0.012; percentage: 35.9%±8.9% vs 44.9%±8.0%,P= 0.021], number of neutrophils in the liver, and MPO activity (3.52±1.03 U/g vs 4.72±1.09 U/g,P= 0.040), as well as significantly inhibited expression of inflammatory cytokines and chemokines (TNF-α: 2.458±0.762 vs 3.778±1.046, P = 0.005; IL-1β: 2.498±0.547 vs 4.065 ± 0.953,P= 0.002; IFN-γ: 3.977±1.039 vs 5.418±1.255, P = 0.025; IL-10: 6.056±1.542 vs 3.368±0.952,P= 0.001; CXCL1: 7.988±1.911 vs 10.366±1.239,P= 0.010; CXCL2: 3.441±1.005 vs 4.847±1.113,P= 0.019). Conclusion: BMSC transplantation has a therapeutic effect on D-galactosamine-induced acute liver failure in rats, and this process is accompanied by reduced aggregation and activity of neutrophils in peripheral blood and liver. Inflammatory cytokines and chemokines may be involved in the mechanism of regulation of these two aspects.

Posterior second sacral alar iliac screw insertion: anatomic study in a Chinese population

OBJECTIVE

To provide radiographic parameters for optimal placement of posterior second sacral alar iliac (S2AI) screw for instrumentation and fusion of scoliosis to the second sacral level in a Chinese population.

METHODS

S2AI screw trajectories were mapped on three-dimensional computed tomography (3DCT) reconstructions of 60 normal adult pelvises. 1 mm inferior and 1 mm lateral to the S1 dorsal foramen were chosen as the entry point, and ideal S2AI screw trajectories were explored by rotating and cutting the 3D pelvis, ensuring that the trajectories were of maximum length and width. The directions and depth of these determined trajectories were then measured.

RESULTS

The ideal S2AI screw trajectories could be found in each pelvis. The left and right screw trajectory parameters for males were shown as follows: angulation was L 29.15 ± 8.60° vs. R 29.96 ± 8.28° (p = 0.286) caudally in the sagittal plane and L 36.49 ± 3.14° vs. R 37.16 ± 3.14° (p = 0.165) laterally in the transverse plane. The maximal and intrasacral lengths of trajectory were L 121.25 ± 8.33 vs. R 120.63 ± 7.54 mm (p = 0.460) and L 26.20 ± 3.31 vs. R 26.92 ± 4.76 mm (p = 0.268). The entry point was L 28.87 ± 3.33 vs. R 29.79 ± 3.55 mm (p = 0.186) lateral to the second sacral midline, and L 44.14 ± 11.87 vs. R 43.89 ± 12.53 mm (p = 0.687) underneath the skin. The trajectories for females were more caudal (L: 34.50 ± 6.56° vs. 29.15 ± 8.60°, p = 0.009; R: 35.72 ± 7.53° vs. 29.96 ± 8.28°, p = 0.007) in the sagittal plane, but the lateral angulation in the transverse plane showed no difference between genders (p > 0.05). The female iliac medullar cavities were obviously narrower than those of males (L: 14.76 ± 2.46 vs. 16.98 ± 3.52, p = 0.006; R: 14.94 ± 2.60 vs. 17.00 ± 2.81, p = 0.005). Although the average maximal length of trajectories for females were about 5 mm shorter than those of males, intrasacral length were equal to those of males. Furthermore, both the distance from entry point to the S2 midline and skin in the transverse plane showed no difference between genders.

CONCLUSION

The feasibility to insert S2AI screws to the sacrum and ilium in an Asian population along with the ideal entry angle and length of trajectory were identified for clinical practice.

Systematic review and meta-analysis of triclosan-coated sutures for the prevention of surgical-site infection

Background

Surgical-site infections (SSIs) increase morbidity and mortality in surgical patients and represent an economic burden to healthcare systems. Experiments have shown that triclosan-coated sutures (TCS) are beneficial in the prevention of SSI, although the results from individual randomized controlled trials (RCTs) are inconclusive. A meta-analysis of available RCTs was performed to evaluate the efficacy of TCS in the prevention of SSI.

Methods

A systematic search of PubMed, Embase, MEDLINE, Web of Science®, the Cochrane Central Register of Controlled Trials and internet-based trial registries for RCTs comparing the effect of TCS and conventional uncoated sutures on SSIs was conducted until June 2012. The primary outcome investigated was the incidence of SSI. Pooled relative risks with 95 per cent confidence interval (c.i.) were estimated with RevMan 5.1.6.

Results

Seventeen RCTs involving 3720 participants were included. No heterogeneity of statistical significance across studies was observed. TCS showed a significant advantage in reducing the rate of SSI by 30 per cent (relative risk 0·70, 95 per cent c.i. 0·57 to 0·85; P &lt; 0·001). Subgroup analyses revealed consistent results in favour of TCS in adult patients, abdominal procedures, and clean or clean-contaminated surgical wounds.

Conclusion

TCS demonstrated a significant beneficial effect in the prevention of SSI after surgery.

[Normothermic total hepatic vascular exclusion for hepatectomy]

Experience of normothermic total hepatic vascular exclusion for hepatectomy in two patients with hepatocarcinoma in the second porta hepatis area are reported. The combined method of stepwise exclusion of porta hepatis, total hepatic vascular exclusion, total hepatic vascular exclusion without abdominal aorta and manipulative exclusion of inferior vena cava above liver are described. Biochemical studies before, during and after the operation showed that they are similar to these of routine hepatectomy. This modification, being safer and easier, may increase the resectability and reduce the mortality rate.