Spatial distribution of perfluoroalkyl acids (PFAAs) and their precursors and conversion of precursors in seawater deeply affected by a city in China

Conversion of perfluoroalkyl acid (PFAA) precursors in the environment has been a hotspot research in recent years. This study firstly determined the spatial distribution of PFAAs and their precursors including 8:2 fluorotelomer unsaturated acid (8:2 FTUCA), perfluorooctane sulfoneamide (FOSA), and diperfluorooctane sulfonamido ethanol-based phosphate (di-SAmPAP), then investigated the conversion of the potential precursors in the seawater and sewage treatment plants (STPs) effluents. The results indicated that the target pollutants showed a typical concentration gradient from nearshore to offshore. And the obviously increased concentration of perfluorinated carboxylic acids (△[PFCAs]) after oxidation treatment can verify the existence of PFAA precursors in the seawater and STP effluents. The concentrations of PFCAs with carbon atom numbers 4-9 (PFCA_C4-C9) revealed the most increase. Moreover, the levels of △[PFCAs] and the ratios of △[PFCAs] to their concentration before oxidation (△[PFCA]/[PFCA]_{before oxidation}) indicated obvious spatial variations in the seawater and STP effluents. The higher levels of △[PFCA_C4-C12] and the lower ratios of ∑△[PFCA_C4-C12]/∑[PFAA]_{before oxidation} were observed in the STP effluents, which implied that precursors might be decomposed during the sewage treatment process. These results suggested the STP effluents might have an important effect on the PFAAs levels of seawater.

[WITHDRAWN: Potential false-positive rate among the 'asymptomatic infected individuals' in close contacts of COVID-19 patients]

Editor office’s response for Ahead of Print article withdrawn The article “Potential false-positive rate among the ‘asymptomatic infected individuals’ in close contacts of COVID-19 patients” was under strong discussion after pre-published. Questions from the readers mainly focused on the article’s results and conclusions were depended on theoretical deduction, but not the field epidemiology data and further researches were needed to prove the current theory. Based on previous discussions, the article was decided to be offline by the editorial board from the pre-publish lists. Objective: As the prevention and control of COVID-19continues to advance, the active nucleic acid test screening in the close contacts of the patients has been carrying out in many parts of China. However, the false-positive rate of positive results in the screening has not been reported up to now. But to clearify the false-positive rate during screening is important in COVID-19 control and prevention. Methods: Point values and reasonable ranges of the indicators which impact the false-positive rate of positive results were estimated based on the information available to us at present. The false-positive rate of positive results in the active screening was deduced, and univariate and multivariate-probabilistic sensitivity analyses were performed to understand the robustness of the findings. Results: When the infection rate of the close contacts and the sensitivity and specificity of reported results were taken as the point estimates, the positive predictive value of the active screening was only 19.67%, in contrast, the false-positive rate of positive results was 80.33%. The multivariate-probabilistic sensitivity analysis results supported the base-case findings, with a 75% probability for the false-positive rate of positive results over 47%. Conclusions: In the close contacts of COVID-19 patients, nearly half or even more of the 'asymptomatic infected individuals' reported in the active nucleic acid test screening might be false positives.

Extracellular Histone Promotes Prostate Cancer Migration and Epithelial-Mesenchymal Transition through NF-κB-Mediated Inflammatory Responses

INTRODUCTION

This study aims to explore the relationship betweenextracellular histone and prostate cancer and its mechanism.

METHODS

Migration of prostate cancer cells was detected by Transwell. Inflammatory factor expression was investigated by ELISA. Epithelial-mesenchymal transition and expression of NF-κB pathway-related proteins were investigated using Western blotting.

RESULTS

Under the induction of extracellular histones, the migration rate of prostate cancer cells and the levels of IL-1β, TNF-α, and IL-6 were notably enhanced. Then, expression of E-cadherin was significantly down-regulated, while levels of N-cadherin, vimentin, β-catenin, Snail, p-p65 and p-IκBα were significantly up-regulated, which was reversed by PDTC (pyrrolidine dithiocarbamate).

CONCLUSION

Extracellular histone significantly promotes the progression of prostate cancer cells via NF-κB pathway-mediated inflammatory responses, which may serve as a novel target for treating prostate cancer.

[Risk factor analysis on anastomotic leakage after laparoscopic surgery in rectal cancer patient with neoadjuvant therapy and establishment of a nomogram prediction model]

Objective: To investigate the risk factors of anastomotic leakage (AL) after laparoscopic surgery in rectal cancer patient with neoadjuvant therapy and construct a nomogram prediction model. Methods: This study was a retrospective case-control study that collected and reviewed the clinicopathological data of 359 patients who underwent laparoscopic surgery from January 2012 to January 2018, including 202 patients from the Department of General Surgery, Nanfang Hospital of Southern Medical University and 157 patients from the Department of Gastrointestinal Surgery of Fujian Provincial Cancer Hospital. Inclusion criteria: (1) age ≥ 18 years old; (2) diagnosis as rectal cancer by biopsy before treatment; (3) distance from tumor to anus within 12 cm; (4) locally advanced stage (T3-T4 or N+) diagnosed by imaging (CT, MRI, PET or ultrasound); (5) standardized neoadjuvant therapy followed by laparoscopic radical operation. Exclusion criteria: (1) previous history of colorectal cancer surgery; (2) short-term or incomplete standardized neoadjuvant therapy; (3) Miles, Hartmann, emergency surgery, palliative resection; (4) conversion to open surgery. Clinicopathological data, including age, gender, body mass index (BMI), preoperative albumin, distance from tumor to anus, operation hospital, American Society of Anesthesiologists score (ASA score), operation time, T stage, N stage, M stage, TNM stage, pathological complete response (pCR) were analyzed with univariate analysis to identify predictors for AL after laparoscopic surgery in rectal cancer patient with neoadjuvant therapy. Then, incorporated predictors of AL, which were screened by multivariate logistic regression, were plotted by the "rms" package in R software to establish a nomogram model. According to the scale of the nomogram of each risk factor, the total score could be obtained by adding each single score, then the corresponding probability of postoperative AL could be acquired. The area under ROC curve (AUC) was used to evaluate the predictive ability of each risk factor and nomogram on model. AUC > 0.75 indicated that the model had good predictive ability. The Bootstrap method (1000 bootstrapping resamples) was applied as internal verification to show the robustness of the model. The discrimination of the nomogram was determined by calculating the average consistency index (C-index) whose rage was 0.5 to 1.0. Higher C-index indicated better consistency with actual risk. The calibration curve was used to assess the calibration of prediction model. The Hosmer-Lemeshow test yielding a non-significant statistic (P>0.05) suggested no departure from the perfect fit. Results: Of 359 cases, 224 were male, 135 were female, 189 were ≥ 55 years old, 98 had a BMI > 24 kg/m(2), 176 had preoperative albumin ≤ 40 g/L, 128 had distance from tumor to anus ≤ 5 cm, 257 were TNM 0-II stage, 102 were TNM III-IV stage, and 84 achieved pCR after neoadjuvant therapy. The incidence of postoperative AL was 9.5% (34/359). Univariate analysis showed that gender, preoperative albumin and distance from tumor to the anus were associated with postoperative AL (All P<0.05). Multivariate logistic regression analysis revealed that male (OR=2.480, 95% CI: 1.012-6.077, P=0.047), preoperative albumin ≤40 g/L (OR=5.319, 95% CI: 2.106-13.433, P<0.001) and distance from tumor to anus ≤ 5 cm (OR=4.339, 95% CI: 1.990-9.458, P<0.001) were significant independent risk factors for postoperative AL. According to these results, a nomogram prediction model was constructed. The male was for 55 points, the preoperative albumin ≤ 40 g/L was for 100 points, and the distance from tumor to the anus ≤ 5 cm was for 88 points. Adding all the points of each risk factor, the corresponding probability of total score would indicated the morbidity of postoperative AL predicted by this nomogram modal. The AUC of the nomogram was 0.792 (95% CI: 0.729-0.856), and the C-index was 0.792 after internal verification. The calibration curve showed that the predictive results were well correlated with the actual results (P=0.562). Conclusions: Male, preoperative albumin ≤ 40 g/L and distance from tumor to the anus ≤ 5 cm are independent risk factors for AL after laparoscopic surgery in rectal cancer patient with neoadjuvant therapy. The nomogram prediction model is helpful to predict the probability of AL after surgery.

Risk Factors for 3-Year-Mortality and a Tool to Screen Patient in Dialysis Population

Introduction

Clinical parameters especially co-morbidities among end stage renal disease (ESRD) patients are associated with mortality. This study aims to determine the risk factors that are associated with mortality within three years among prevalent patients with ESRD.

Methods

This is a cohort study where prevalent ESRD patients' details were recorded between May 2012 and October 2012. Their records were matched with national death record at the end of year 2015 to identify the deceased patients within three years. Four models were formulated with two models were based on logistic regression models but with different number of predictors and two models were developed based on risk scoring technique. The preferred models were validated by using sensitivity and specificity analysis.

Results

A total of 1332 patients were included in the study. Majority succumbed due to cardiovascular disease (48.3%) and sepsis (41.3%). The identified risk factors were mode of dialysis (P < 0.001), diabetes mellitus (P < 0.001), chronic heart disease (P < 0.001) and leg amputation (P = 0.016). The accuracy of four models was almost similar with AUC between 0.680 and 0.711. The predictive models from logistic regression model and risk scoring model were selected as the preferred models based on both accuracy and simplicity. Besides the mode of dialysis, diabetes mellitus and its complications are the important predictors for early mortality among prevalent ESRD patients.

Conclusions

The models either based on logistic regression or risk scoring model can be used to screen high risk prevalent ESRD patients.

[Effect of preservation of left colic artery on postoperative anastomotic leakage of patients with rectal cancer after neoadjuvant therapy]

Objective: To evaluate the effect of preservation of left colic artery (LCA) on postoperative anastomotic leakage in patients with rectal cancer after neoadjuvant therapy. Methods: A retrospective cohort study was conducted to collect data of rectal cancer patients at Department of Gastrointestinal Surgery of Fujian Cancer Hospital from September 2014 to August 2017. Inclusion criteria: (1) age of 18 to 79 years; (2) rectal adenocarcinoma confirmed by postoperative pathology; (3) patients without preoperative serious cardiovascular and cerebrovascular disease receiving preoperative neoadjuvant radiotherapy or chemoradiotherapy; (4) laparoscopic-assisted anterior rectal resection and distal ileostomy were performed simultaneously; (5) complete clinical data. Exclusion criteria: patients with extensive abdominal metastasis, or distant organ metastasis during operation, and combined organ resection. According to whether LCA was retained during operation, the patients were divided into two groups, then the intraoperative and postoperative clinical outcomes were compared. Moreover, univariate analysis and multivariate logistic regression were used to analyze risk factors of postoperative anastomotic leakage. Results: A total of 125 patients were included in this study, including 56 patients in the retained LCA group and 69 patients in the non-retained LCA group. Differences in baseline data, such as gender, age, diabetes mellitus, body mass index, hemoglobin, distance between tumor and anal margin, maximum diameter of tumor, preoperative neoadjuvant therapy, and ypTNM stage, between retained LCA group and non-retained LCA group were not statistically significant (all P>0.05), indicating that two groups were comparable. Meanwhile there were no significant differences in operation time, intraoperative blood loss, total number of lymph node harvested, number of harvested lymph node at the root of inferior mesenteric artery, circumferential margin, anastomotic bleeding, or postoperative hospital stay between two groups (all P>0.05). Thirteen patients in the non-retained LCA group (18.8%) developed postoperative anastomotic leakage, including 7 cases of grade A, 5 cases of grade B and 1 case of grade C, while in the retained LCA group, only 5.4% (3/56) of patients developed postoperative anastomotic leakage, including 1 case of grade A and 2 cases of grade B without case of grade C, whose difference was statistically significant (U=1674.500, P=0.028). Univariate analysis showed that preoperative hemoglobin <120 g/L and non-retained LCA were associated with postoperative anastomotic leakage (both P<0.05). Multivariate analysis cofirmed that preoperative hemoglobin < 120 g/L (OR=3.508, 95% CI: 1.158 to 10.628, P=0.017) and non-retained LCA (OR=4.065, 95%CI: 1.074 to 15.388, P=0.031) were independent risk factors for postoperative anastomotic leakage. Median follow-up time was 31 months (16 to 51 months), and no long-term complication was found. Local recurrence and distant metastasis were found in 1 case (1.8%) and 7 case (12.5%) in the retained LCA group, while those were found in 2 cases (2.9%) and 5 cases (7.2%) respectively, in the non-retained LCA group, whose differences were not statistically significant (P=1.000, P=0.321 respectively). Conclusion: Preservation of left colic artery not only can ensure radical lymph node dissection efficacy under the condition of similar operation time and blood loss, but also can effectively reduce the incidence of postoperative anastomotic leakage for rectal cancer patients after neoadjuvant therapy.

Synthesis of high quality silver nanowires and their applications in ultrafast photonics

Silver nanowires are widely used in catalysts, surface enhanced Raman scattering, microelectronic equipment, thin film solar cells, microelectrodes and biosensors for their excellent conductivity, heat transfer, low surface resistance, high transparency and good biocompatibility. However, the optical nonlinearity of silver nanowires has not been further explored yet. In this paper, three silver nanowire samples with different concentrations are produced via a typical hydrothermal method. Their applications to fiber lasers are implemented to prove the optical nonlinearity of silver nanowires for the first time. Based on three kinds of silver nanowires, the mode-locked operation of fiber lasers is successfully realized. Moreover, the fiber laser based on the silver nanowire with a concentration of 2 mg/L demonstrates the shortest pulse duration of 149.3 fs. The experiment not only proves the optical nonlinearity of silver nanowires, but also has some enlightenment on the selection of the optimum concentration of silver nanowires in the consideration of ultrashort pulse output.

Nonlinear optical properties of MoS2-WS2 heterostructure in fiber lasers

As a saturable absorption material, the heterostructure with the van der Waals structure has been paid much attention in material science. In general, the heterogeneous combination is able to neutralize, or even exceed, the individual material's advantages in some aspects. In this paper, which describes the magnetron sputtering deposition method, the tapered fiber is coated by the MoS₂-WS₂ heterostructure, and the MoS₂-WS₂ heterostructure saturable absorber (SA) is fabricated. The modulation depth of the prepared MoS₂-WS₂ heterostructure SA is measured to be 19.12%. Besides, the theoretical calculations for the band gap and carrier mobility of the MoS₂-WS₂ heterostructure are provided. By employing the prepared SA, a stable and passively erbium-doped fiber laser is implemented. The generated pulse duration of 154 fs is certified to be the shortest among all fiber lasers based on transition mental dichalcogenides. Results in this paper provide the new direction for the fabrication of ultrafast photon modulation devices.

A sub-megavolt anti-scattering grid: Fabrication, testing, and Monte Carlo simulation

X-ray flash radiography is an effective diagnostic in implosive research. While scattering reduces the contrast of radiography, the anti-scattering grids can effectively intercept the scattered radiation and acquire better images. A focused sub-megavolt grid is elaborately manufactured with the combination of lithography, etching, and laser drilling. The consistency of Monte Carlo simulations and radiographic experiments suggests a transmission of about 36% and a 1000 times improvement for the signal to scatter ratio of the grid.

[Meta analysis on effectiveness of epidermal growth factor in treating patients with inhalation injury]

Objective: To systematically evaluate the effectiveness of epidermal growth factor (EGF) in treating patients with inhalation injury by meta analysis. Methods: Databases including PubMed, Cochrance Library, and Embase were searched using key words " inhalation injury, smoke inhalation injury, epidermal growth factor, and EGF" , and Chinese Journals Full-text Database, China Biology Medicine disc, VIP Database, and Wanfang Database were searched using key words in Chinese version "," to obtain the randomized controlled trails about EGF published publicly in the treatment of patients with inhalation injury from the establishment of each database to December 2017. The measurement indexes included content of total protein and albumin, colloid osmotic pressure (COP), the number of total cells, percentages of neutrophils, lymphocytes, and fibroblasts in bronchoalveolar lavage fluid (BALF), the time of disappearance of pulmonary symptoms, the time of exfoliation of necrotic mucous membrane, the time of removal of tracheal tube, the amount of respiratory secretions, and the incidence of lung infection. Meta-analysis was conducted by RevMan 5.3 statistical software. Results: A total of 6 trials involving 375 patients were included, with 182 patients in group EGF who received EGF treatment and 173 patients in conventional treatment group who received conventional treatment. All of the 6 trails had unclear risk of bias. The content of total protein and albumin and COP in BALF of patients in group EGF were lower than those in conventional treatment group, with standardized mean differences (SMDs) respectively -9.37, -26.77 , and -8.13 [with 95% confidence intervals (CIs) respectively -14.11--4.63, -41.85--11.69, -9.54--6.73, P<0.001]. The number of total cells and percentages of neutrophils and lymphocytes in BALF of patients in group EGF were lower than those in conventional treatment group, while the percentage of fibroblasts in BALF of patients in group EGF was higher than that in conventional treatment group, with SMDs respectively -20.22, -13.08, -12.28, 2.99 (with 95% CIs respectively -22.27--17.66 , -14.76--11.40, -13.86--10.70, 2.48-3.50, P<0.001). The time of disappearance of pulmonary symptoms, the time of exfoliation of necrotic mucous membrane, and the time of removal of tracheal tube of patients in group EGF were shorter than those in conventional treatment group, with SMDs respectively -1.05, -1.22 , -1.11 (with 95% CIs respectively -1.36--0.74, -1.54--0.91, -1.39--0.82, P<0.001). The amount of respiratory secretions of patients in group EGF was lower than that in conventional treatment group, with SMD -1.44 (with 95% CI -1.90--0.98, P<0.001). The incidence rate of pulmonary infection of patients in group EGF was lower than that in conventional treatment group, with relative risk 0.46 (with 95% CI 0.24-0.89, P<0.05). There may be publication bias in the content of total protein, albumin, and COP in BALF (P<0.05), while the time of disappearance of pulmonary symptoms, the time of exfoliation of necrotic mucous membrane, and the time of removal of tracheal tube showed no significant publication bias (P>0.05). Conclusions: Conventional treatment combined with EGF therapy can reduce respiratory inflammation of inhalation injury, promote restoration of respiratory epithelium, shorten the time of removal of tracheal tube, reduce the incidence of pulmonary infection of patients, and therefore has good effect on inhalation injury.

[Effects of anteriolateral thigh perforator flap and fascia lata transplantation in combination with computed tomography angiography on repair of electrical burn wounds of head with skull exposure and necrosis]

Objective: To explore the effects of anteriolateral thigh perforator flap and fascia lata transplantation in combination with computed tomography angiography (CTA) on repair of electrical burn wounds of head with skull exposure and necrosis. Methods: Seven patients with head electrical burns accompanied by skull exposure and necrosis were admitted to our burn center from March 2016 to December 2017. Head CTA was performed before the operation. The diameters of the facial artery and vein or the superficial temporal artery and vein were measured, and their locations were marked on the body surface. Preoperative CTA for flap donor sites in lower extremities were also performed to track the descending branch of the lateral circumflex femoral artery with the similar diameter as the recipient vessels on the head, and their locations were marked on the body surface. Routine wound debridement and skull drilling were performed successively. The size of the wounds after debridement ranged from 12 cm×8 cm to 20 cm×12 cm, and the areas of skull exposure ranged from 8 cm×6 cm to 15 cm×10 cm. Anteriolateral thigh perforator flaps with areas from 13 cm×9 cm to 21 cm×13 cm containing 5-10 cm long vascular pedicles were designed and dissected accordingly. The fascia lata under the flap with area from 5 cm×2 cm to 10 cm×3 cm was dissected according to the length of vascular pedicle. The fascia lata was transplanted to cover the exposed skull, and the anteriolateral thigh perforator flap was transplanted afterwards. The descending branch of the lateral circumflex femoral artery and its accompanying vein of the flap were anastomosed with superficial temporal artery and vein or facial artery and vein before the suture of flap. The flap donor sites were covered by intermediate split-thickness skin graft collected from contralateral thigh or abdomen. Results: The descending branch of the lateral circumflex femoral artery and its accompanying vein were anastomosed with superficial temporal artery and vein in six patients, while those with facial artery and vein in one patient. All the flaps survived after the operation, and no vascular crisis was observed. Wound healing was satisfactory. One patient was lost to follow up. Six patients were followed up for 6 to 10 months. The patients were bald in the head operation area with acceptable appearance. No psychiatric symptom such as headache or epileptic seizure was reported. The flap donor sites were normal in appearance. The muscle strength of the lower extremities all reached grade V. The sensation and movement of the lower extremities were normal. Conclusions: Anterolateral thigh perforator flap with fascia lata transplantation can effectively repair electrical burn wounds of head with skull exposure and necrosis. The fascia lata can be used to protect the vascular pedicle of flaps, which is beneficial to the survival of the flap. Preoperative head and lower extremities CTA can provide reference for intraoperative vascular exploration in donor site and recipient area, so as to shorten operation time.

Testing for a slope-based decoupling algorithm in a woofer-tweeter adaptive optics system

It is well known that using two or more deformable mirrors (DMs) can improve the compensation ability of an adaptive optics (AO) system. However, to keep the stability of an AO system, the correlation between the multiple DMs must be suppressed during the correction. In this paper, we proposed a slope-based decoupling algorithm to simultaneous control the multiple DMs. In order to examine the validity and practicality of this algorithm, a typical woofer-tweeter (W-T) AO system was set up. For the W-T system, a theory model was simulated and the results indicated in theory that the algorithm we presented can selectively make woofer and tweeter correct different spatial frequency aberration and suppress the cross coupling between the dual DMs. At the same time, the experimental results for the W-T AO system were consistent with the results of the simulation, which demonstrated in practice that this algorithm is practical for the AO system with dual DMs.

Direct Growth of Al2O3 on Black Phosphorus by Plasma-Enhanced Atomic Layer Deposition

Growing high-quality and uniform dielectric on black phosphorus is challenging since it is easy to react with O₂ or H₂O in ambient. In this work, we have directly grown Al₂O₃ on BP using plasma-enhanced atomic layer deposition (PEALD). The surface roughness of BP with covered Al₂O₃ film can reduce significantly, which is due to the removal of oxidized bubble in BP surface by oxygen plasma. It was also found there is an interfacial layer of PO _x in between amorphous Al₂O₃ film and crystallized BP, which is verified by both X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) measurements. By increasing temperature, the PO _x can be converted into fully oxidized P₂O₅.

[Comparison on the efficacy and safety of different occlusion devices for the treatment of patients with patent foramen ovale]

Objective: To compare the efficacy and safety of Cardi-O-fix patent foramen ovale (PFO) occluder and Amplatzer PFO occluder for the treatment of patients with PFO. Methods: A total of 246 consecutive patients (105 males and 141 females) with PFO were prospectively enrolled from May 30, 2013 to March 30, 2015 in our hospital. PFO interventional closure was applied according to the anatomical structure of the disease and patients' wishes.Cardi-O-fix PFO occluder was used in 180 cases (COF group), Amplatzer PFO occluder was used in the remaining 66 cases (Amp group). Post-procedure safety including recurrent stroke, transient ischemic attack, death, and complete closure rate, and efficacy including procedure related complications of different devices were compared during the 12 months follow-up. Results: (1) Rate of transient ischemic attack was similar between COF group and Amp group at 12 months after procedure(1.1%(2/180) vs. 1.5%(1/66), P=1.000). There was no recurrent stroke and death during the 12 months follow-up period.Complete closure rate was similar between COF group and Amp group at 12 months after the procedure(90.6%(163/180)vs. 86.4%(57/66), P=0.355). (2) Three cases(1.7%) of paroxysmal atrial fibrillation were observed in COF group during the 12 months follow-up period, 1 patient converted spontaneously to sinus rhythm and 2 patients received successful pharmacologic conversion and converted to sinus rhythm. One patient(1.5%)developed paroxysmal atrial fibrillation and was pharmacologically converted to sinus rhythm in the Amp group. There was no significant difference in rate of paroxysmal atrial fibrillation between the two groups(P=1.000). There was no complications such as occluder translocation, erosion, pericardial effusion and puncture site bleeding in the 2 groups during the 12 months follow-up. Conclusion: Efficacy and safety are similar for PFO treatment with Cardi-O-fix PFO occluder or Amplatzer PFO occluder in this patient cohort.

[Effect of trichostatin A on the osteogenic differentiation potential of periodontal ligament stem cells in inflammatory microenvironment induced by tumor necrosis factor-α stimulation]

OBJECTIVE

To compare the expression of histone deacetylase(HDAC)1-11 of human periodontal ligament stem cells(PDLSC)in normal and inflammatory microenvironments, and to investigate the effect of histone deacetylase inhibitor trichostatin A(TSA)on the osteogenic differentiation potential of PDLSC in inflammatory microenvironment induced by tumor necrosis factor-α(TNF-α)stimulation.

METHODS

PDLSC were isolated from periodontal ligament tissues obtained from the surgically extracted human teeth and cultured by single-colony selection. The expression of HDAC1-11 in cells with or without TNF-α(10 μg/L)stimulation was evaluated by quantitative real time-PCR(RT-PCR). The effect of TSA on cell proliferation was investigated by methyl thiazolyl tetrazolium(MTT)assay. The influence of TSA on osteogenic differentiation of PDLSC in inflammatory microenvironment with TNF-α stimulation was assessed by alizarin red staining, quantitative RT-PCR and Western blotting, respectively.

RESULTS

The expression of HDAC in PDLSC with TNF-α stimulation was significantly higher than that in normal PDLSC(P<0.05)(except HDAC7, P=0.243). TSA had no significant effect on PDLSC proliferation at the concentration of 50 nmol/L(P=0.232). The alizarin red staining showed that PDLSC in TNF-α group generated less mineralized nodule than the control group, while the cell matrix mineralization in TSA group was improved obviously. TNF-α had an inhibitory effect on the expression of osteogenesis related genes, runt-related transcription factor-2(RUNX2)and alkaline phosphatase(ALP), with relative gene expression ratio(experimental/control)decreased to 0.17 ± 0.02 and 0.32 ± 0.03, while TSA could significantly increase the genes' expression to 0.67±0.03 and 0.89±0.02(P<0.01). Western blotting test showed that in TNF-α group the expression of osteogenesis related proteins was obviously reduced, and compared with the TNF-α group, TSA could significantly promote the expression of proteinsin inflammatory microenvironment.

CONCLUSIONS

PDLSC in inflammatory microenvironment by TNF-α stimulation had a higher expression of HDAC than that in normal conditions. TSA, as a histone deacetylase inhibitor, could significantly promote the osteogenic differentiation potential of PDLSC in inflammatory microenvironment by suppressing HDAC.

[Relative analysis of platelet activation with bleeding risk in patients with primary immune thrombocytopenia]

目的

研究原发免疫性血小板减少症（ITP）患者血小板活化状态和出血程度的相关性。

方法

采用ITP特异性出血评价工具（ITP-BAT）对43例ITP患者进行出血评分及出血程度分级，应用流式细胞术检测二磷酸腺苷（ADP）激活前后血小板膜糖蛋白（GP）Ⅰb、Ⅱb/Ⅲa和P选择素表达。分析GPⅠb、GPⅡb/Ⅲa、P选择素表达与血小板计数、未成熟血小板比例的相关性；分析GPⅠb、GPⅡb/Ⅲa、P选择素表达与ITP患者出血程度的相关性，以及对中度以上出血患者风险评估的应用价值。

结果

ITP患者激活前血小板GPⅡb/Ⅲa、P选择素表达均高于正常对照组（65.69±10.73对7.16±0.99，t=4.130，P<0.001；15.43±1.41对12.55±1.03，t=2.070，P=0.043），GPⅠb表达低于正常对照组（240.11±24.93对295.11±22.15，t=2.417，P=0.020）。ITP患者ADP激活后血小板GPⅡb/Ⅲa表达高于正常对照组（133.96±12.17对39.67±4.99，t=5.256，P<0.001），而P选择素、GPⅠb表达低于正常对照组（37.09±3.94对109.77±23.66，t=3.901，P<0.001；149.06±19.14对205.73±21.00，t=2.070，P=0.043）。ADP激活后GPⅠb表达、ADP激活前后P选择素表达及ADP激活前后GPⅠb、P选择素表达比值与血小板计数相关（P<0.05）。ADP激活后P选择素表达、ADP激活前后P选择素表达比值与未成熟血小板比例相关（P<0.05）。ITP患者ADP激活后GPⅠb表达、ADP激活前后P选择素表达及ADP激活前后P选择素、GPⅡb/Ⅲa、GPⅠb表达比值在不同出血程度之间差异有统计学意义（P<0.05）。ADP激活前后GPⅠb表达比值是ITP患者中度以上出血的正性影响因素（OR=3.05，P=0.011），ADP激活前后P选择素、GPⅡb/Ⅲa表达比值是ITP患者中度以上出血的负性影响因素（OR=0.32，P=0.023；OR=0.04，P=0.006）。

结论

血小板活化指标能较准确地评估ITP患者出血程度，可以作为治疗参考指标和疗效观察指标。

Fine mapping and candidate gene analysis of Brtri1, a gene controlling trichome development in Chinese cabbage (Brassica rapa L. ssp pekinensis)

Trichomes are derived from the epidermis and constitute an ideal system for studying cell division in plants. Here, a Chinese cabbage doubled haploid (DH) line (FT) without trichomes was crossed with another DH line (PurDH-1) with trichomes to develop an F₂ population for fine mapping of trichome control genes. Genetic analysis showed that the trichome phenotype was controlled by a single dominant gene, Brtri1. Using 1226 glabrous individuals in the F₂ segregation population, Brtri1 was localized to a 16.84 kb region between markers Pur6-31 and Pur6-39 on chromosome A06. One of the four complete open reading frames within the mapping region, Bra025311, encodes a MYB transcription factor and is highly homologous to the trichome regulatory gene GL1 in Arabidopsis thaliana. It was thus regarded as a candidate gene for Brtri1. Comparative sequencing showed a 5-bp deletion in the third exon of Bra025311 in FT, resulting in a frame-shift mutation. No expression of Bra025311 was detected in FT. A co-dominant indel marker close to this mutation site was developed for marker-assisted selection in Chinese cabbage breeding.

Long-term exposure of K562 cells to benzene metabolites inhibited erythroid differentiation and elevated methylation in erythroid specific genes

Benzene is a common occupational hazard and a widespread environmental pollutant. Previous studies have revealed that 72 h exposure to benzene metabolites inhibited hemin-induced erythroid differentiation of K562 cells accompanied with elevated methylation in erythroid specific genes. However, little is known about the effects of long-term and low-dose benzene metabolite exposure. In this study, to elucidate the effects of long-term benzene metabolite exposure on erythroid differentiation, K562 cells were treated with low-concentration phenol, hydroquinone and 1,2,4-benzenetriol for at least 3 weeks. After exposure of K562 cells to benzene metabolites, hemin-induced hemoglobin synthesis declined in a concentration- and time-dependent manner, and the hemin-induced expressions of α-, β- and γ-globin genes and heme synthesis enzyme porphobilinogen deaminase were significantly suppressed. Furthermore, when K562 cells were continuously cultured without benzene metabolites for another 20 days after exposure to benzene metabolites for 4 weeks, the decreased erythroid differentiation capabilities still remained stable in hydroquinone- and 1,2,4-benzenetriol-exposed cells, but showed a slow increase in phenol-exposed K562 cells. In addition, methyltransferase inhibitor 5-aza-2'-deoxycytidine significantly blocked benzene metabolites inhibiting hemoglobin synthesis and expression of erythroid genes. Quantitative MassARRAY methylation analysis also confirmed that the exposure to benzene metabolites increased DNA methylation levels at several CpG sites in several erythroid-specific genes and their far-upstream regulatory elements. These results demonstrated that long-term and low-dose exposure to benzene metabolites inhibited the hemin-induced erythroid differentiation of K562 cells, in which DNA methylation played a role through the suppression of erythroid specific genes.