Observation of D_{s}^{±}/D^{0} Enhancement in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

We report on the first measurement of charm-strange meson D_{s}^{±} production at midrapidity in Au+Au collisions at sqrt[s_{NN}]=200  GeV from the STAR experiment. The yield ratio between strange (D_{s}^{±}) and nonstrange (D^{0}) open-charm mesons is presented and compared to model calculations. A significant enhancement, relative to a pythia simulation of p+p collisions, is observed in the D_{s}^{±}/D^{0} yield ratio in Au+Au collisions over a large range of collision centralities. Model calculations incorporating abundant strange-quark production in the quark-gluon plasma and coalescence hadronization qualitatively reproduce the data. The transverse-momentum integrated yield ratio of D_{s}^{±}/D^{0} at midrapidity is consistent with a prediction from a statistical hadronization model with the parameters constrained by the yields of light and strange hadrons measured at the same collision energy. These results suggest that the coalescence of charm quarks with strange quarks in the quark-gluon plasma plays an important role in D_{s}^{±}-meson production in heavy-ion collisions.

[Causal relationship between physical exercise and risk of ischemic stroke recurrence based on the potential outcome theory]

OBJECTIVE

To explore the causal relationship between physical exercise and ischemic stroke recurrence using a multiple imputation approach based on the potential outcomes framework.

METHODS

We collected data from 636 patients who were diagnosed with first-ever ischemic stroke between July, 2010 and December, 2018 at West China Hospital, Sichuan University.All the patients had motor ability and were followed up at least for 1 year.According to the intensity of physical exercise, the patients were divided into low-level physical exercise (LPE) group (n=244) and moderate-to high-intensity exercise (MHPE) group (n=392).With both the result and the time of recurrence as the potential outcomes, a multiple imputation method was used to impute the missing values based on a predictive matrix.Based on the imputed datasets, a causal inference model was built to estimate the average causal effect of physical exercise on the risk of stroke recurrence.

RESULTS

Among the enrolled patients, 148 experienced recurrent stroke with a median recurrence time of 24.0 months and a cumulative recurrence rate of 23.3%during follow-up.As there were no outliers and the marginal distributions of the potential outcomes were basically consistent, both the Strip plots and Kenel density plots indicated that the imputed values could have been plausible measurements if they had not been missing.The average causal effect (ACE) of physical exercise on stroke recurrence was 0.578 (95%CI: 0.186-0.970, P=0.012).

CONCLUSION

There is a causal relationship between physical exercise and the risk of ischemic stroke recurrence, indicating the value of moderate or high-level exercise after stroke in reducing the risk of stroke recurrence.

Long-term aesthetics, patient-reported outcomes, and auricular sensitivity after microtia reconstruction: A systematic review

BACKGROUND

Auricular reconstruction for microtia is most frequently performed using autologous costal cartilage (ACC) or porous polyethylene (PPE) implants. Short-term results are generally promising, but long-term results remain unclear. Long-term outcomes were explored in this systematic review, and minimal reporting criteria were suggested for future original data studies.

METHODS

A systematic literature search was conducted in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials from inception through October 14, 2020. Articles on auricular reconstruction in patients with microtia using ACC or PPE were included if postsurgical follow-up was at least 1 year. Outcome reporting was split into separate publications, and results on complications were reported previously. This publication focused on long-term aesthetic, patient-reported, and sensitivity outcomes.

RESULTS

Forty-one publications reported on these outcomes. Both materials led to aesthetically pleasing results and high rates of patient satisfaction. ACC frameworks grew similarly to contralateral ears, and the anterior surface of auricles regained sensitivity. Furthermore, postoperative health-related quality of life (HRQoL) outcomes were generally good. Data synthesis was limited due to considerable variability between studies and poor study quality. No conclusions could be drawn on the superiority of either method due to the lack of comparative analyses.

CONCLUSION

Future studies should minimally report (1) surgical efficacy measured using the tool provided in the UK Care Standards for the Management of Patients with Microtia and Atresia; (2) complications including framework extrusion or exposure, graft loss, framework resorption, wire exposure and scalp/auricular scar complications and (3) HRQoL before and after treatment using the EAR-Q patient-reported outcome measure (PROM).

Long-term complications of microtia reconstruction: A systematic review

BACKGROUND

Microtia is a rare disorder characterized by malformation or even complete absence of the auricle. Reconstruction is often performed using autologous costal cartilage (ACC) or porous polyethylene implants (PPE). However, the long-term outcomes of both methods are unclear.

OBJECTIVE

This systematic review aimed to analyze long-term complications and suggest minimal reporting criteria for future original data studies.

METHODS

A systematic literature search was conducted in MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials from inception through October 14, 2020. Articles on auricular reconstruction in patients with microtia using ACC or PPE were included provided that the follow-up period was at least one year. This publication focused on long-term complications reported in patients with a postoperative follow-up period of at least one year.

RESULTS

Twenty-nine publications reported on complications during long-term follow-up. Overall long-term complication rates were not reported. The incidence of individual complications during long-term follow-up was less than 10% after ACC reconstruction and less than 15% in PPE reconstruction. Framework resorption and wire exposure were reported even after an extended follow-up of more than five years after ACC reconstruction, while reports on the extended long-term results of PPE reconstruction are limited. Data synthesis was limited due to heterogeneity and poor study quality.

CONCLUSIONS

Future studies should report on long-term complications including framework exposure or extrusion, graft loss, framework resorption, wire exposure and scalp and auricular scar complications. We recommend a surgical follow-up of at least five years.

Targeting STING attenuates ROS induced intervertebral disc degeneration

OBJECTIVE

DNA damage induced by ROS is considered one of the main causes of nucleus pulposus (NP) cells degeneration during the progression of intervertebral disc degeneration (IVDD). cGAS-STING pathway acts as DNA-sensing mechanism for monitoring DNA damage. Recent studies have proved that cGAS-STING contributes to the development of various diseases by inducing inflammation, senescence, and apoptosis. This work explored the role of STING, the main effector of cGAS-STING signaling pathway, in NP degeneration.

METHOD

Immunohistochemistry was conducted to measure STING protein levels in the nucleus pulposus tissues from human and puncture-induced IVDD rat models. TBHP induces degeneration of nucleus pulposus cells in vitro. For in vivo experiments, lv-NC or lv-STING were injected into the central intervertebral disc space. The degeneration level of IVDD was assessed by MRI, X-ray, HE, and Safranin O staining.

RESULTS

We found that the expression of STING was upregulated in human and rat degenerated NP tissue as well as in TBHP-treated NP cells. Overexpression of STING promoted the degradation of extracellular matrix; it also promoted apoptosis and senescence of TBHP-treated and untreated NP cells. Knock-down of STING significantly reversed these effects. Mechanistically, STING activated IRF3, whereas blockage of IRF3 attenuated STING-induced apoptosis, senescence and ECM degradation. In vivo experiments revealed that STING knock-down alleviated puncture-induced IVDD development.

CONCLUSION

STING promotes IVDD progress via IRF3, while suppression of STING may be a promising treatment for IVDD.

Measurement of e^{+}e^{-} Momentum and Angular Distributions from Linearly Polarized Photon Collisions

The Breit-Wheeler process which produces matter and antimatter from photon collisions is experimentally investigated through the observation of 6085 exclusive electron-positron pairs in ultraperipheral Au+Au collisions at sqrt[s_{NN}]=200  GeV. The measurements reveal a large fourth-order angular modulation of cos4Δϕ=(16.8±2.5)% and smooth invariant mass distribution absent of vector mesons (ϕ, ω, and ρ) at the experimental limit of ≤0.2% of the observed yields. The differential cross section as a function of e^{+}e^{-} pair transverse momentum P_{⊥} peaks at low value with sqrt[⟨P_{⊥}^{2}⟩]=38.1±0.9  MeV and displays a significant centrality dependence. These features are consistent with QED calculations for the collision of linearly polarized photons quantized from the extremely strong electromagnetic fields generated by the highly charged Au nuclei at ultrarelativistic speed. The experimental results have implications for vacuum birefringence and for mapping the magnetic field which is important for emergent QCD phenomena.

Superficial versus deep system single venous anastomosis in the radial forearm free flap: a meta-analysis

The selection of the superficial or deep drainage system for use with the radial forearm free flap (RFFF) remains controversial. The aim of this study was to identify the optimal drainage system for single venous anastomosis. A systematic review and cumulative meta-analysis was performed to assess superficial and deep system single venous anastomosis for use with the RFFF in postoperative reconstruction of the head and neck. This study included 1073 flaps (495 superficial system-based flaps, 578 deep system-based flaps) reported in six studies. The outcomes assessed in the studies selected for this meta-analysis included venous compromise, flap failure, and the salvage success rate. Venous compromise was more common in the superficial system group (odds ratio (OR) 2.29, 95% confidence interval (CI) 1.36-3.86, P=0.002). The rate of successful salvage was higher with the superficial system (OR 8.19, 95% CI 1.75-38.3, P=0.008). The rate of flap failure was lower in the superficial system group (OR 0.30, 95% CI 0.04-2.48, P=0.27). Although the deep system showed a lower risk of venous compromise, the evidence provided by the meta-analysis was insufficient to determine which type of drainage system is more suitable for single venous anastomosis in RFFF. All included studies were cohort studies; therefore, findings must be interpreted with caution.

Upregulation of long noncoding RNA FERRE promoted growth and invasion of breast cancer through modulating miR-19a-5p/EZH2 axis

OBJECTIVE

It has been demonstrated that long non-coding RNA (LncRNA) plays an important regulatory role in a series of diseases. The purpose of this study is to investigate the expression of long non-coding RNA (LncRNA) FERRE and its facilitating effects on proliferation and invasion of breast cancer by regulating oncogene EZH2 through sponging with miR-19a-5p.

PATIENTS AND METHODS

qRT-PCR was performed to detect the expressions of FERRE and EZH2 in human breast cancer tissues and cells. CCK-8 assay was performed to evaluate the MCF-7 cells proliferation and transwell assay was performed to evaluate the MCF-7 cells migration. Correlation analysis between FERRE and miR-19a-5p was detected by statistical analysis. Bioinformatics prediction was made to detect the binding site of FERRE and miR-19a-5p and Luciferase activity was conducted to investigate the interaction between EZH2 and miR-19a-5p. Furthermore, we cloned the mice EZH2 3'-UTR into the Luciferase reporter vector and constructed miR-19a-5p binding mutants to validate the inhibited modulation of miR-19a-5p to the EZH2 expression.

RESULTS

Results showed that expression of FERRE and EZH2 were upregulated in human breast cancer tissues and cells. qRT-PCR and CCK-8 assay showed that FERRE expression is associated with the proliferation of breast cancer cells, upregulated FERRE contributed to cell proliferation of MCF-7. Transwell assay showed that FERRE was associated with the migration ability of tumor cells, increased expression of FERRE promoted the migration and invasion of breast cancer cells. The bioinformatics prediction and Luciferase assay demonstrated that by sponging with miR-19a-5p, FERRE can serve as a molecular sponge to further regulate the expression of EZH2.

CONCLUSIONS

We found that lncRNA-FERRE was upregulated in human breast cancer patients, which could accelerate tumor proliferation, migration and invasion as a molecular sponge by modulating the inhibitory effect of miR-19a-5p on oncogene EZH2.

[The effect of visualized saphenous nerve block through minimally invasive far medial-subvastus approach on the analgesia after total knee arthroplasty]

Objective: To report a method of visualized saphenous nerve block (VSNB) through minimally invasive far medial-subvastus approach distal to the adductor canal in total knee arthroplasty (TKA), and investigate the effect of VSNB in this way on postoperative pain relief. Methods: A total of 100 patients with knee osteoarthritis were prospectively included from June 2018 to October 2019, 29 males and 71 females, aged 50-87(70±8) years. All patients undergoing TKA through minimally invasive far medial-subvastus approach were randomized to visualized saphenous nerve block combined with periarticular infiltration analgesia group (Group VSNB+PIA) or only periarticular infiltration analgesia group (Group PIA),50 cases in each group. The visual analogue scale (VAS) was used to evaluate the pain degree of patients. Furthermore, the scores of VAS in resting and active state at 4, 8, 12, 24, 48, 72 hours after operation and the proportion of patients receiving parecoxib within 72 hours after operation were compared between the two groups. Results: There was statistically significant difference between the two groups in terms of VAS scores in resting state after surgery(F=15.295,P<0.05).The postoperative VAS scores of Group VSNB+PIA at 4, 8, 12, 24 hours at resting state were 1.3±0.8, 1.4±0.7, 1.7±0.8, 3.1±0.8 respectively, which were all significantly lower than those of Group PIA (1.6±0.9, 1.8±0.8, 2.3±0.9, 3.6±0.8) (P<0.05). The overall difference in terms of VAS scores at active state after surgery was statistically significant between the two groups(F=18.532, P<0.05). The postoperative VAS scores of Group VSNB+PIA at 4, 8, 12, 24 hours at active state were 2.0±0.8, 2.2±0.7, 2.7±0.6, 3.7±0.7 respectively, which were all significantly lower than those of Group PIA (2.3±0.8, 2.7±0.7, 3.3±0.8, 4.4±0.7)(P<0.05). Fourteen percent of patients (7/50) in VSNB+PIA group accepted parecoxib within 72 hours after surgery, which was significantly lower than that in PIA group (34%, 17/50) (P<0.05). Conclusions: It is easy to expose the saphenous nerve beyond the adductor canal through minimally invasive far medial-subvastus approach. The Combination therapy of VSNB+PIA is more effective than the simple per-articular infiltration analgesia in providing pain relief after total knee arthroplasty.

[Dose-effect relationship between serum polycyclic aromatic hydrocarbon adducts and serum complements among children in a city of East China]

Objective: To investigate the dose-response relationship between serum polycyclic aromatic hydrocarbon adducts and serum complement C3 and C4 levels among children from a city in East China. Methods: In September 2016, two boarding schools in the air pollution exposure area and the control area (beyond the upwind of 30 km in the air pollution exposure area) in a city in East China were selected as the research site, and the eligible school-age children were recruited as the research objects. A total of 273 children were included, including 163 in the exposure group and 110 in the control group. The annual air pollutant data (PM_2.5, PM₁₀ and NO₂) of the two regions during the study period were collected. The exposure level of tobacco was evaluated by cotinine in urine. The levels of serum complement C3 and C4 were determined by automatic biochemical analyzer. The serum anti-7, 8, -dihydrodiol-9, 10-epoxide benzo[a]pyrene (BPDE)-albumin adduct levels were detected by ELISA. Linear regression model was used to explore the dose-response relationship between BPDE-albumin adducts and serum complement C3 and C4. Results: The age of 273 subjects was (13.67±0.37) years old, including 165 boys (60.4%). The average annual exposure levels of PM_2.5, PM₁₀ and NO₂ and the level of serum BPDE-albumin adducts in the exposure group were higher than those in the control group (P<0.05). The results of linear regression model analysis showed that after adjusting age, sex, BMI z-score and urinary cotinine level, when the serum BPDE-albumin adduct level increased by 10%, the serum complement C4 level decreased by 1.2% (P=0.017). After adjusting age, BMI z-score and urinary cotinine level, for every 10% increase in serum BPDE-albumin adduct level in boys, the serum complement C4 level decreased by 1.68% (P=0.024). After adjusting age, sex and BMI z-score, the levels of serum complement C3 and C4 decreased by 1.31% and 3.57% respectively for every 10% increase in serum BPDE-albumin adducts among children in the urinary cotinine detection group (P<0.05). Conclusion: There is a significant dose-response relationship between serum BPDE-albumin adducts and the complement C4 among children.

The use of PacBio SMRT technology to explore the microbial network and fermentation characteristics of woody silage prepared with exogenous carbohydrate additives

AIMS

To effectively use woody plant resources to prepare silage for ruminants, Pacific Biosciences (PacBio) single-molecule real-time (SMRT) sequencing was applied to study the microbial network and fermentation characteristics of paper mulberry (PM) silage prepared with corn meal (CM) and rice bran (RB) as exogenous additives.

METHODS AND RESULTS

PM is rich in nutrients and contains more than 26% crude protein in dry matter. After ensiling, the microbial diversity and abundance in PM, CM and RB decreased due to the anaerobic environment and acidic conditions. The CM-treated PM silage accelerated the conversion of the dominant microbial community from harmful bacteria to lactic acid bacteria and promoted lactic acid fermentation. When RB was used to treat PM silage, Enterobacter and Clostridium species became the main bacterial community during ensiling, leading to butyric acid fermentation and protein decomposition. Compared with RB, CM increased the amount of fermentation substrates, changed the microbial community structure and affected metabolic pathways (global metabolism, carbohydrate metabolism and amino acid metabolism), which improved the flavour and quality of the PM silage.

CONCLUSIONS

The CM addition of improved the fermentation quality of PM silage, with PM + CM being the ideal combination. The SMRT sequencing technology could accurately obtain specific details of the microbial networks and fermentation characteristics. Our results indicate that PM can be used as a potential high-protein silage in animal production.

SIGNIFICANCE AND IMPACT OF THE STUDY

In tropics, the effective use of abundant natural biomass resources such as woody plants to prepare silage for feed preservation can solve the problem of restricting livestock production due to the shortage of feed in the dry season. SMRT sequencing technology was used to accurately analyze the microbial network and fermentation characteristics of woody silage prepared with CM as an exogenous additive to improve the fermentation quality of silage.

Global Polarization of Ξ and Ω Hyperons in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

Global polarization of Ξ and Ω hyperons has been measured for the first time in Au+Au collisions at sqrt[s_{NN}]=200  GeV. The measurements of the Ξ^{-} and Ξ[over ¯]^{+} hyperon polarization have been performed by two independent methods, via analysis of the angular distribution of the daughter particles in the parity violating weak decay Ξ→Λ+π, as well as by measuring the polarization of the daughter Λ hyperon, polarized via polarization transfer from its parent. The polarization, obtained by combining the results from the two methods and averaged over Ξ^{-} and Ξ[over ¯]^{+}, is measured to be ⟨P_{Ξ}⟩=0.47±0.10(stat)±0.23(syst)% for the collision centrality 20%-80%. The ⟨P_{Ξ}⟩ is found to be slightly larger than the inclusive Λ polarization and in reasonable agreement with a multiphase transport model. The ⟨P_{Ξ}⟩ is found to follow the centrality dependence of the vorticity predicted in the model, increasing toward more peripheral collisions. The global polarization of Ω, ⟨P_{Ω}⟩=1.11±0.87(stat)±1.97(syst)% was obtained by measuring the polarization of daughter Λ in the decay Ω→Λ+K, assuming the polarization transfer factor C_{ΩΛ}=1.

[Baseline characteristics of the participants of China National Birth Cohort]

Objective: To explore the effects of environmental, genetic factors as well as the interactions in early life on the short-term and long-term health of offspring and to systematically evaluate the pregnancy outcomes and health of offspring after birth between families with assisted reproductive technology (ART) conception and families with spontaneous conception. Methods: The China National Birth Cohort (CNBC), a multicenter prospective birth cohort study, includes both families with ART conception and families with spontaneous conception. Since 2016, CNBC has recruited families from 24 hospitals located in 12 provinces, municipalities and autonomous regions throughout China. Information and biospecimens were collected before ART treatment, embryo transfer, at early, second, third trimester and delivery, and at 42 days, 6, 12 and 36 months after birth. Results: By June 2020, CNBC had included 27 044 families with ART conception and 29 589 families with spontaneous conception. The majority of the participants are urban residents. Among the families with ART conception, 65.5% of the men and 63.7% of the women had college degrees or higher. The mean age distribution of men and women was (33.83±5.52) and (32.38±4.67) years. 83.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.8% and 2.1% in women. Among the families with spontaneous conception, 81.5% of the men and 86.5% of the women had college degrees or higher. The mean age distribution of men and women was (32.06±5.09) and (30.40±4.27) years. 67.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.1% and 2.2% in women. The baseline characteristics were different between the families with ART conception and spontaneous conception in different regions. Conclusion: CNBC provides a powerful and rich resource in studying the impact of genetic, environmental factors and interactions in early life and ART treatment on the health of offspring after birth.

[Profile of China National Birth Cohort]

With the rapid changes in lifestyle, natural and social environment, the reproductive health status of couples in childbearing age continues to decline, and long-term outcomes of the rapidly increasing offspring conceived by assisted reproductive technology (ART) needs to be evaluated urgently. Therefore, the focus of research now needs to be extended from death and severe diseases to full life cycle and full disease spectrum. In order to meet the demand for such research, we launched the China National Birth Cohort (CNBC) study, an ongoing prospective and longitudinal study aiming to recruit 30 000 families underwent ART and 30 000 families with spontaneous pregnancies. Long-term follow-up programs will be conducted for both spouses and their offspring. Data of couples and their offspring, such as environmental exposure, reproductive history, psychological and behavioral status, will be collected during follow-up. Peripheral blood, urine, umbilical blood, follicular fluid, semen were also collected at different follow-up nodes. Based on high-quality data and biological samples, CNBC will play an extremely important supporting role and have a far-reaching impact on maternal and children's health care and reproductive health in China. This paper is exactly a brief introduction to the construction and basic design of CNBC.

[A sub-cohort study design of the maternal and infant microbes in China National Birth Cohort]

The importance of gut microbes to human health has gradually attracted attention. With the use of animal models, it has been revealed that maternal microbes during pregnancy could influence their children's health outcomes through shaping their microbial composition and regulating the development of their metabolic and immune system. However, the physiological mechanism of the human body is more complex and is affected by the interaction of multiple factors. The research results obtained from animal models are often inconsistent with human studies. At present, the influence of maternal intestinal microbes during pregnancy on the microbial colonization in their offspring and on a series of children's health outcomes is still unclear. Establishing a sub-cohort to detect the microbiome of the women across pregnancy and of their offspring, and further to integrate with variety of environmental and behavioral exposures can better provide reliable support for the research on the mechanism of children's health and diseases. This paper briefly introduces the research objectives, content, progress, strength and limitations of the sub-cohort study.

[The Autism Spectrum Disorder Cohort-the sub-cohort of China National Birth Cohort]

Autism spectrum disorder (ASD), a representative disease of children's neurodevelopmental disorders, brings huge pressure and financial burden to families and society. It is of great significance to explore its etiology and pathogenesis. Therefore, we established an ASD Cohort based on the existing China National Birth Cohort (CNBC), which applied parallel design to recruit and follow up families who achieved pregnancy after receiving assisted reproductive technologies (ART) and families with spontaneous conception. The main aims of this study are to compare the incidence of ASD among children born after ART with those born under spontaneous pregnancy, and to evaluate the impact of ART on the neurobehavioral development of offspring. Additionally, with a variety of clinical and behavioral related information collected during pregnancy and at early life of offspring, we are able to investigate the risk factors associated with ASD comprehensively. This article briefly introduces the objectives, contents, preliminary progress, strength and limitations, as well as further prospects of the ASD cohort study, mainly focusing on the overall design and current progress.

[Application of cloud-based information platform in China National Birth Cohort]

Birth cohort is an important observational study which can continuously and dynamically collect the exposure changes and health outcomes from gametophyte development to adolescence and even old age. However, because of its complex design and difficult implementation, how to construct birth cohort with high quality and high efficiency is the main difficulty faced by epidemiologists at home and abroad. In 2016, China National Birth Cohort was officially launched. The network and information technology were used to explore, and a set of "cloud-based information platform" was established to support this queue construction, containing 16 units in China. After four years of development, the platform has formed a complete set of programs about the construction of cohort information platform, which including recruitment and follow-up management of participants, real-time data interaction, queue quality control, multi-level authority management and function division. The relevant design framework and functional elements provide the references to the future information construction of large-scale birth cohort and even population-based research in China.

[Quality control and measures of China National Birth Cohort]

Birth cohort is an effective method to explore the relationship between various prepregnant and pregnant exposures and the health of fetuses, infants and young children. It is a long construction period to build a birth cohort and the quality of research may be affected by many factors. This paper reviews the quality assurance and quality control measures in the process of China National Birth Cohort (CNBC), and summarizes the construction experience. We aim to provide experience for related cohort studies, which could improve the quality of cohort studies through removing the impact of related factors. CNBC adopted a series of measures to ensure the quality of research in the top-level design of quality assurance, including screening research center, developing member management system, formulating standard operating procedures and training staff by it. In terms of quality control, it includes real-time, timely and timing quality control for the process of data generation, full-cycle quality control for biological sample collection, processing, storage and comprehensive three-dimensional quality control for staff training, supervision and quantitative assessment.

EpsR Negatively Regulates Streptococcus mutans Exopolysaccharide Synthesis

Streptococcus mutans is considered the primary etiological agent of human dental caries. Glucosyltransferases (Gtfs) from S. mutans play important roles in the formation of biofilm matrix and the development of cariogenic oral biofilm. Therefore, Gtfs are considered an important target to prevent the development of dental caries. However, the role of transcription factors in regulating gtf expression is not yet clear. Here, we identify a MarR (multiple antibiotic resistance regulator) family transcription factor named EpsR (exopolysaccharide synthesis regulator), which negatively regulates gtfB expression and exopolysaccharide (EPS) production in S. mutans. The epsR in-frame deletion strain grew slowly, aggregated more easily in the presence of dextran, and displayed different colony morphology and biofilm structure. Notably, epsR deletion resulted in altered 3-dimensional biofilm architecture, increased water-insoluble EPS production, and upregulated GtfB protein content and activity. In addition, global gene expression profiling revealed differences in the expression levels of 69 genes in which gtfB was markedly upregulated. The conserved DNA motif for EpsR binding was determined by electrophoretic mobility shift assay and DNase I footprinting assays. Moreover, analysis of β-galactosidase activity suggested that EpsR acted as a repressor and inhibited gtfB expression. Taken together, our findings indicate that EpsR is an important transcription factor that regulates gtfB expression and EPS production in S. mutans. These results add new aspects to the complexity of regulating the expression of genes involved in the cariogenicity of S. mutans, which might lead to novel strategies to prevent the formation of cariogenic biofilm that may favor diseases.

VO-OHpic attenuates intervertebral disc degeneration via PTEN/Akt pathway

OBJECTIVE

Intervertebral disc degeneration (IVDD) is mainly associated with a chronic process of the nucleus pulposus (NP) cells disabled. Also, it is accepted to be the basic result of low back pain. The role of phosphatase and tensin homolog (PTEN) in negatively regulating the Akt/PKB signaling, which is the major cell survival pathway, has been documented in previous studies. The present work aimed to investigate the role of PTEN inhibitor VO-OHpic (VO) in the protection of IVDD and to explore its potential mechanisms.

PATIENTS AND METHODS

NP cells isolated from patients' lumbar discs were subjected to different concentrations of IL-1β or H2O2 to establish NP cells degenerated model. Cell proliferation was analyzed by the Cell Counting Kit-8 (CCK-8) assay. The expression levels of collagen II, aggrecan, PTEN, PI3K, Akt, SOD1, SOD2, p16, and β-galactosidase (β-gal) were detected by Western blotting, immunofluorescence staining or RT-PCR. Flow cytometry was used to measure the ROS level and cell cycle distribution.

RESULTS

Our research showed that collagen II, aggrecan, PI3K, and Akt markedly decreased in IL-1β- or H2O2-induced degenerated NP cells. VO could reverse the effects of IL-1β and H2O2 by the PTEN inhibition. Also, we found that VO increased the antioxidant enzymes SOD1, SOD2, CAT, GSH, POD production, and suppressed the ROS in the disc. Besides, data showed VO promoted NP cells proliferation by cell cycle mediation.

CONCLUSIONS

These results suggest that VO treatment prevents NP degradation via restraining oxidative stress and increasing cell proliferation through the PTEN/Akt pathway in vitro. VO may become a novel cytokine for the therapy of IVDD in the future.

Nonmonotonic Energy Dependence of Net-Proton Number Fluctuations

Nonmonotonic variation with collision energy (sqrt[s_{NN}]) of the moments of the net-baryon number distribution in heavy-ion collisions, related to the correlation length and the susceptibilities of the system, is suggested as a signature for the quantum chromodynamics critical point. We report the first evidence of a nonmonotonic variation in the kurtosis times variance of the net-proton number (proxy for net-baryon number) distribution as a function of sqrt[s_{NN}] with 3.1  σ significance for head-on (central) gold-on-gold (Au+Au) collisions measured solenoidal tracker at Relativistic Heavy Ion Collider. Data in noncentral Au+Au collisions and models of heavy-ion collisions without a critical point show a monotonic variation as a function of sqrt[s_{NN}].

Characterization of the key region and putative phosphorylation sites of EcaICE1 in its molecular interaction with the EcaHOS1 protein in Eucalyptus camaldulensis

Inducer of CBF expression 1 (ICE1), a MYC-like bHLH transcriptional activator, plays an important role in plants under cold stress. The ubiquitination-proteasome pathway mediated by high expression of osmotically responsive gene1 (HOS1) can effectively induce the degradation of ICE1 and decrease the expression of CBFs and their downstream genes under cold stress response in Arabidopsis, but knowledge of ubiquitination regulation of ICE1 by HOS1 is still limited in woody plants. In this study, a E3 ubiquitin ligase gene EcaHOS1 were amplified from Eucalyptus camaldulensis and the protein interactions between EcaICE1 and EcaHOS1 were analysed. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assay results showed that EcaICE1 can interact with the EcaHOS1 protein in the nucleus and, further, the Y2H assay demonstrated that the 126-185 amino acid region at the N-terminus of the EcaICE1 protein was indispensable for its interaction with EcaHOS1 protein. Moreover, we found that the amino acids at positions 145, 158 and 184 within the key interaction region were the putative phosphorylation sites of EcaICE1, based on bioinformatics analysis, and only the substitution of serine (Ser) 158 by alanine (Ala) blocked the protein-protein interactions between EcaICE1 and EcaHOS1 based on Y2H and β-galactosidase activity assays using site-directed mutagenesis. We identified Ser 158 of EcaICE1 as the key putative phosphorylation site for its interaction with the EcaHOS1 protein.