Objective To assess on-related association and causality of vitamin C supplementation and sepsis risk by using two-sample Mendelian randomization(MR)design.Methods The study was based on Genome-Wide Association Studies data to screen single nucleotide polymorphisms associated with vitamin C supplementation as instrumental variables.The association of vitamin C supplementation and risk of sepsis was assessed by MR Egger,weighted median,inverse variance weighting,simple model,and weighted model.Results Inverse variance weighting showed a significant negative association between vitamin C supplementation and the risk of sepsis(P=0.030).Sensitivity analysis was consistent with no significant evidence of significant heterogeneity or pleiotropy.Conclusion There is a potential reverse causal relationship between vitamin C supplementation and reduced sepsis risk,and appropriate vitamin C supplementation may provide a feasible intervention for sepsis prevention.

Objective To assess on-related association and causality of vitamin C supplementation and sepsis risk by using two-sample Mendelian randomization(MR)design.Methods The study was based on Genome-Wide Association Studies data to screen single nucleotide polymorphisms associated with vitamin C supplementation as instrumental variables.The association of vitamin C supplementation and risk of sepsis was assessed by MR Egger,weighted median,inverse variance weighting,simple model,and weighted model.Results Inverse variance weighting showed a significant negative association between vitamin C supplementation and the risk of sepsis(P=0.030).Sensitivity analysis was consistent with no significant evidence of significant heterogeneity or pleiotropy.Conclusion There is a potential reverse causal relationship between vitamin C supplementation and reduced sepsis risk,and appropriate vitamin C supplementation may provide a feasible intervention for sepsis prevention.

OBJECTIVEUsing tooth whitening agents (bleaching clip) in vitro and acidic drinks, we conducted a comparative study of the changes in enamel surface morphology, Ca/P content, and hardness.

METHODSTooth whitening glue pieces, cola, and orange juice were used to soak teeth in artificial saliva in vitro. Physiological saline was used as a control treatment. The morphology of the four groups was observed under a scanning electron microscope (SEM) immediately after the teeth were soaked for 7 and 14 d. The changes in Ca/P content and microhardness were analyzed.

RESULTSThe enamel surfaces of the teeth in the three test groups were demineralized. The Ca/P ratio and the average microhardness were significantly lower than those of the control group immediately after the teeth were soaked (P < 0.05). The Ca/P ratio and microhardness gradually increased after 7 d. No significant difference was observed between the control group and the test groups after 14 d (P > 0.05).

CONCLUSIONBleaching agents caused transient demineralization of human enamel, but these agents could induce re-mineralization and repair of enamel over time. Demineralization caused by bleaching covered a relatively normal range compared with acidic drinks and daily drinking.

Dental Enamel ; Hardness ; Humans ; Hydrogen Peroxide ; Saliva, Artificial ; Surface Properties ; Tooth Bleaching ; Tooth Bleaching Agents

Objective To study the effects of pulse high volume hemofiltration (PHVHF) on the changes of Th17 cells (T helper 17 cells) and CD4 + CD25 + reguratory T cells (Treg cells) in peripheral blood of patients with sepsis and to evaluate the clinical value of this intervention. Methods The patients were included in this prospective study as per the criteria of sepsis set by America Chest Physicians College/America Society for Critic Care Medicine in 1992. The patients were excluded: ① immune system disorder, ② acute stroke, ③ myocardial infarction, ④ virus hepatitis,⑤ human immunodeficiency virus infection, ⑥ under immunosuppressive therapy. Forty patients (24 males, 16 females, aged from 25 to 75years) with sepsis in ICU were enrolled from January. 2008 to November. 2010. According to the severity of disease, the patients were divided into three groups; moderate sepsis group (n = 14, 8 males, 6 females) , severe sepsis group (n = 15, 9 males, 6 females) , and septic shock group (n = 11, 7 males, 4 females). The initially clinical data of three groups were comparable. Twenty healthy individuals served as controls. According to the mode of treatment, forty patients were also divided into two groups: conventional treatment group (group A, n= 15) in which patients were treated without PHVHF within 5 days after admission and trial group (group B, n=25) in which patients were treated with pulsed high volume hemofiltration (PHVHF) within 5 days after admission. In group B, high volume hemofiltration (70 mL · kg-1 · h-1) was given to patients for 6 ～ 8 hours, and then conventional continuous vein - vein hemofiltration (35 mL · kg-1 · h-1) for 16 ~ 18 hours. The total length of period for continuum blood scavenging was 24 hours as one cycle. The interval between two cycles of blood scavenging was 24 hours. The changes of Th17 cells and CD4+ CD25 + Treg cells of 40 patients were detected with flow cytometry on the 1st day and the 5th day after admission. The data were analyzed by using SPSS version 13. 0 software. Measurement data were analyzed with Paired-samples t-test, independent-samples t-test or one way ANOVA . Ratio of small samples was compared with fisher's exact test, and the correlation was analyzed by using Pearson correlation analysis. Results The rates of Th17 cells were( 0.91 ±0.38)%, (2.09 ±0. 53)% , (3.90 ±0. 80)% , and ( 1. 85 ±0.35)% in control, moderate sepsis, severe sepsis, and septic shock groups, respectively, while the rates of CD4+ CD25+ Treg cells were (0.39 ±0.23)%, (1. 72 ±0. 59)% , (2.72 ±0. 22)% , and (3. 55 ±0. 51)% , respectively. The rate of Thl7 cells on the 1st day was higher in severe sepsis group than that in other two groups ( P < 0. 05 ) without significant difference between septic shock and moderate sepsis groups ( P > 0. 05). Moreover , the rate of CD4+ CD25 + Treg cells was up - regulated on the 1st day in the following order from high to low: septic shock group > severe sepsis group > sepsis group (P < 0.05). The rates of Th17 cells and CD4 + CD25 + Treg cells in patients of group B decreased in greater degree than that did in patients of group A (P < 0.05 ). Conclusions The changes of Th17 cells and CD4 + CD25 + Treg cells may play an important role in pathogenesis of sepsis, and the pulsed high volume hemofiltration may be one of the effective treatments for the patients with sepsis by regulating the rates of Thl7 cells and CD4 + CD25 + Treg cells.