Measures for waste and by-product recycling and circular economy of whole industry chain of traditional Chinese medicine resources facing carbon peak and carbon neutrality (dual carbon) goals / 中国中药杂志

It has become a common consensus that resource conservation and intensive recycling for improving resource utilization efficiency is an important way to achieve carbon peak and carbon neutrality(dual carbon). Traditonal Chinese medicine(TCM)resources as national strategic resources are the material basis and fundamental guarantee for the development of TCM industry and health services. However, the rapid growth of China's TCM industry and the continuous expansion and extension of the industrial chain have exposed the low efficiency of TCM resources. Resource waste and environmental pollution caused by the treatment and discharge of TCM waste have emerged as major problems faced by the development of the industry, which has aroused wide concern. Considering the dual carbon goals, this paper expounds the role and potential of TCM resource recycling and circular economy industry development. Taking the typical model of TCM resource recycling as the case of circular economy industry in reducing carbon source and increasing carbon sink, this paper puts forward the suggestions for the TCM circular economy industry serving the double carbon goals. The suggestions mainly include strengthening the policy and strategic leading role of the double carbon goals, building an objective evaluation system of low-carbon emission reduction in the whole industrial chain of TCM resources, building an industrial demonstration park for the recycling of TCM resources, and promoting the establishment of a circular economy system of the whole industrial chain of TCM resources. These measures are expected to guide the green transformation of TCM resource industry from linear economic model to circular economy model, provide support for improving the utilization efficiency and sustainable development of TCM resources, and facilitate the low-carbon and efficient development of TCM resource industry and the achievement of the double carbon goals.

Recent research on the application of defoamers in children undergoing digestive endoscopy / 中国当代儿科杂志

Endoscopy is a common tool for the diagnosis and treatment of gastrointestinal disorders in children. The presence of bubbles in the gastrointestinal tract is one of the important factors affecting the clarity of endoscopic visual field, and the application of defoamers can significantly reduce bubbles in the gastrointestinal tract, improve the quality of gastrointestinal preparation, and further increase disease detection rate. Various studies have been conducted on gastrointestinal preparation before endoscopy in children, but there still lacks a uniform protocol for the application of defoamers. This article summarizes the use of defoamers in children before digestive endoscopy and related research advances and points out that existing studies on defoamers have a small sample size and that there are still controversies over the selection and timing of administration, so as to provide a reference for in-depth research on defoamers in the future.

Progress on the impact of adjacent vertebral arch after single open door laminoplasty / 中国骨伤

Single-door laminoplasty has been widely used in the treatment of multisegment cervical myelopathy, with the clinical advantages of decompression of the spinal cord, relieving preoperative neurological symptoms or signs, and maintaining cervical mobility. However, in clinical work, patients with limited cervical spine activity after single open door laminoplasty are often encountered, and the direct contact with the adjacent vertebral arch can be observed in the postoperative X-ray of the anterior and lateral cervical spine, which is called the adjacent vertebral arch bone impact, which is one of the important causes of the limited cervical spine movement. In recent years, there have been many reports on the prevention of bone impact, although the short-term clinical effect is significant, but long-term clinical efficacy to be further study, and the cause and the pathogenesis of bone impact is no consensus, this paper on the surgery of adjacent vertebral arch impact epidemiology, biomechanics, clinical performance, surgical effect and improvement.

Clinical tolerability and pharmacokinetics of troxacitabine / 中华肿瘤杂志

Objective: To investigate the safety and efficacy of troxatabine in advanced or relapsed malignant tumors resistant to standard therapy in China. Methods: This is a phase Ⅰ prospective study. During dose escalation, patients in Cancer Hospital, Chinese Academy of Medical Sciences received a single-dose intravenous infusion of troxacitabine. The planned dosing groups were 1.8, 3.6, 4.8, 6.4 and 8.0 mg/m(2) on days 1 and 8 every 3 weeks. The data of all patients were collected for safety analyses. Safety and tolerability were evaluated by monitoring adverse events. Results: Nineteen patients were enrolled from April 2018 to May 2019. The major adverse events were fatigue (89.5%, 17/19), leukopenia (84.2%, 16/19) and neutropenia (78.9%, 15/19). The dose limiting toxicity was neutropenia. The maximum tolerated dose was 6.4 mg/m(2). The best effect was stable disease (43.8%). The half-life of elimination phase from 15.91 hours to 76.63 hours in each dose group. Conclusions: The toxicity of troxacitabine is well tolerant. We recommend that the dose for Phase Ⅱ clinical trial should be 6.4 mg/m(2).

High-value utilization technology and approach of Chinese medicinal residues under background of "Dual Carbon" / 中国中药杂志

In recent years, the traditional Chinese medicine(TCM)industry has experienced rapid development, resulting in a significant amount of Chinese medicinal residues generated during the industrial manufacturing process. Currently, the main methods of handling Chinese medicinal residues include stacking, landfilling, and incineration, which lead to substantial resource waste and potential environmental pollution. With "carbon peak" and "carbon neutrality"( "Dual Carbon")becoming national strategic goals, the TCM industry is ushering in a new wave of "low-carbon" trends, and the high-value utilization of Chinese medicinal residues has become a breakthrough for implementing a low-carbon economy in the TCM sector. From the perspective of a low-carbon economy, this article reviewed literature in China and abroad to summarize the microbial transformation technology, enzymatic conversion technology, biomass pyrolysis, gasification, hydrothermal liquefaction, and other high-value utilization technologies for Chinese medicinal residues. It also overviewed the applications of Chinese medicinal residue in feed additives, organic fertilizers, edible mushroom cultivation substrates, preparation of activated carbon for wastewater treatment, and new energy batteries. Considering the current status of resource utilization of Chinese medicinal residues, feasible strategies and suggestions for resource development and utilization were proposed to improve the quality and efficiency of the Chinese medicinal resource industry chain and promote green development, thereby providing research ideas and theoretical basis for achieving carbon peak and carbon neutrality goals.

Analysis of Physiological Function of Escherichia coli Heme Peroxidase EfeB Based on Transcriptome / 中国生物化学与分子生物学报

Heme peroxidase EfeB in E. coli belongs to the dye-decolorizing peroxidase (DyP) superfamily. Peroxidases in this superfamily have a good ability in degradation of synthetic dyes, but their physiological functions in organisms are unclear. In order to further understand the physiological function of EfeB, the mutant strain EcoΔefeB was constructed by homologous recombination. The differences between parental strain E. coli BL21 and EcoΔefeB at genome transcription level as well as cell growth under different conditions were compared. The response of efeB to iron ion was also investigated. The results showed that the deletion of efeB gene caused the differential expression of 1 765 genes, which were mainly related to cell metabolic pathway, cell membrane synthesis and flagellum movement. There was no significant difference in cell growth between BL21 and EcoΔefeB at pH 7. 0, but the growth of BL21 was much better than that of EcoΔefeB at pH 4. 5. The functional expression of efeB may support the survival of E. coli at low pH. EfeB was significantly up-regulated when Fe

Effect of Shenling Baizhusan on Electrogastrogram in Children with Spleen Deficiency Diarrhea / 中国实验方剂学杂志

ObjectiveTo study the effect of Shenling Baizhusan on electrogastrogram in children with spleen deficiency diarrhea. To clarify the occurrence of gastric electrical rhythm disorder in children with this disease， and to study whether Shenling Baizhusan can improve the abnormal gastric motility in children with diarrhea （spleen deficiency） MethodA total of 125 children with spleen deficiency diarrhea in the outpatient department of Children's Hospital of Shanghai from October 2019 to March 2021 were selected as the research objects， and they were randomly divided into a control group （60 cases） and an observation group （65 cases）. The children in the control group were treated with Montmorillonite powder combined with probiotics treatment， and the children in the observation group were additionally treated with Shenling Baizhusan. The course of treatment for both groups was 1 week. The clinical efficacy of the two groups of children after treatment and the scores of main traditional Chinese medcine（TCM） symptoms before and after treatment were compared， and the changes in the main parameters of electrogastrogram in children before and after treatment were compared. ResultAfter treatment， the total effective rate of observation group （90.77%， 59/65） was higher than that of control group （76.67%，46/60） （χ2=4.617， P<0.05）. After treatment， scores of fecal morphology， frequency of defecation， fatigue， inappetence， and other symptoms in both groups were lower than that before treatment （P<0.05）， and the observation group was lower than the control group （P<0.05）. As compared with before treatment， the main frequency， the percentage of normal slow wave， and the percentage of normal gastric electrical rhythm in the two groups increased after treatment （P<0.05）， and the control group was lower than the observation group （P<0.05）. The proportion of children with slow gastric rhythm decreased （P<0.05） as compared with before treatment， and the control group was higher than the observation group （P<0.05）. ConclusionShenling Baizhusan can significantly relieve the diarrhea symptoms in children with spleen deficiency diarrhea and improve gastric motility with good clinical effects.

Clinical outcomes of hip arthroscopic treatment for femoroacetabular impingement:a comparative study between Inside-out and Outside-in approach / 中国骨伤

OBJECTIVE@#To compare the clinical outcomes and complications of hip arthroscopic treatment for femoroacetabular impingement (FAI) performed with either Inside-out or Outside-in approach.@*METHODS@#The clinical date of 48 patients with FAI treated by hip arthroscopy surgery and follow-up from June 2016 to June 2019 were retrospectively analyzed. According to the different operative methods, the patients were divided into two groups. Inside-out group, from central compartment to peripheral compartment;Outside-in group, from peripheral compartment to central compartment. There were 14 males and 10 females in Inside-out group with an averageage of (39.8±7.6)years old, 13 males and 11 females in Inside-out group with an average age of (39.5±9.1)years old in Outside-in group. There was no significant difference in age, gender, body mass index, side, impingement type, medical history and follow-up time between the two groups. The complication occurrence rate, modified Harris hip score (mHHS)and nonarthritic hip score (NAHS) were compared between these two groups.@*RESULTS@#The mHHs and NAHS scores of the two groups were significantly higher than those before operation, but there was no significant difference between the two groups (@*CONCLUSION@#Both hip arthroscopic surgery methods can obtain satisfactory clinical efficacy in the treatment of FAI, but the incidence of postoperative complications of Outside-in surgical method is lower. The out-side in method can be preferentially selected for the patients with the indications of operation.

Scutellarin antagonizing retinal pigment epithelial cell damage induced by high glucose and its molecular mechanism / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the effect of scutellarin on high glucose-induced human retina pigment epithelium(RPE)cells under high glucose. <p>METHODS: RPE cells were cultured and divided into control group(5.5mmol/L glucose), high glucose group(30mmol/L glucose), low concentration scutellarin group(30mmol/L glucose+1μmol/L scutellarin)and high concentration scutellarin group(30mmol/L glucose+10μmol/L scutellarin), cell scratch experiment observed RPE cells migration, cell survival rate were detected by CCK-8 colorimetry, flow cytometry was used to detect the level of ROS, Hoechst staining was used to observe the proportion of apoptotic cells, and Western blot was used to analyze the changes of Bcl-2 and Bax.<p>RESULTS: Cell scratch experiment results showed that RPE cells form in low concentration scutellarin group and high concentration scutellarin group were improved than that in high glucose group, cell mobility rate also increased; The CCK-8 results showed that RPE cells survival rate increased to 61.06%±5.59% and 79.81%±7.04% after treated with 1μmol/L and 10μmol/L scutellarin, the difference was statistically significant when compared with high glucose group(40.63%±4.72%, <i>P</i><0.05); The H2DCFDA fluorescent probe dying showed that scutellarin reduced ROS generation in RPE cells; Hoechst staining showed that the number of apoptosis RPE cells gradually decreased after treatment with 1μmol/L and 10μmol/L scutellarin; Western blot results showed that scutellarin enhanced the expression of Bcl-2 protein and reduced the expression of Bax protein. <p>CONCLUSION: Scutellarin could inhibit high glucose-induced oxidative damage and apoptosis in human RPE cells, which provides theoretical support for the research on the therapeutic targets of diabetic retinopathy.

Identification and Characterization of Gonatobotryum apiculatum CausingLeaf Spot and Blight on Sinowilsonia henryi

Sinowilsonia henryi is a rare and endangered plant, as well as an endemic species in China.In July 2018, leaf spot and blight disease was observed on S. henryi in Yichang, Hubei,China. A fungus isolated from disease tissues was identified as Gonatobotryum apiculatumbased on morphology and sequence analyses of ITS and LSU regions. Phylogenetic analysesindicated that the species belongs to Dothioraceae (Dothideales). Morphologically, the speciesproduced two distinct types of conidia from authentic media, both conidia weredescribed here. Pathogenicity tests showed that the fungus is a pathogen causing leaf spotson S. henryi. This is the first report of leaf spot and blight disease on S. henryi caused byG. apiculatum in China.

Identification and Characterization of Gonatobotryum apiculatum CausingLeaf Spot and Blight on Sinowilsonia henryi

Sinowilsonia henryi is a rare and endangered plant, as well as an endemic species in China.In July 2018, leaf spot and blight disease was observed on S. henryi in Yichang, Hubei,China. A fungus isolated from disease tissues was identified as Gonatobotryum apiculatumbased on morphology and sequence analyses of ITS and LSU regions. Phylogenetic analysesindicated that the species belongs to Dothioraceae (Dothideales). Morphologically, the speciesproduced two distinct types of conidia from authentic media, both conidia weredescribed here. Pathogenicity tests showed that the fungus is a pathogen causing leaf spotson S. henryi. This is the first report of leaf spot and blight disease on S. henryi caused byG. apiculatum in China.

Tissue-engineered cartilage implantation for the treatment of full-thickness knee cartilage defects / 中国组织工程研究

BACKGROUND:The use of normal hyaline cartilage to repair large areas of full-thickness knee cartilage defect has been a hot topic recently; however, a follow-up study with a relative large number of patients is required. OBJECTIVE:To make a preliminary study concerning the methods and therapeutic effects of tissue-engineered cartilage (TEC) implantation for treating large-area full-thickness knee cartilage defects. METHODS:Twenty-one patients (23 knees) diagnosed with cartilage defect of the knee joint (Outbridge III-IV) were enrolled. The area of the cartilage defect was 3.5-11.2 cm2. All of the patients were given TEC treatment. Postoperative functional exercise of the knee joint was carried out in these patients as planned. We regularly reviewed the knee MRI and calculated visual analog scale score, International Knee Documentation Committee (IKDC) score, and Lysholm score. RESULTS AND CONCLUSION:All the patients were followed up for 3 to 12 months. Postoperatively knee pain relieved obviously, and the visual analog scale score was significantly declined compared with the preoperation (P<0.05). All the patients manifested painless 1 year after surgery. The 1-year postoperative MRI showed that the injured cartilage grew well. The thickness and MRI signal of the graft was the same as the normal cartilage, and the bone healed completely. The IKDC and Lysholm scores were significantly improved at 3, 6, 12 months after the surgery, and the difference was statistically significant before and after the surgery (P<0.05). Overall, TEC is an improved technique of chondrocyte implantation, which is an effective and safe method for cartilage defect repair.

Laparoscopic left hepatectomy in swine: a safe and feasible technique

A purely laparoscopic four-port approach was created for left hepatectomy in pigs. A polyethylene loop was placed on the left two hepatic lobes for traction and lift. Next, penetrating ligation of the lobes using of a double row of silk sutures was performed to control bleeding. A direct hepatic transection was completed using a monopolar hook electrode without meticulous dissection of the left hepatic vein. The raw surface of the liver was coagulated and sealed with fibrin glue. Lobes were retrieved through an enlarged portal. Laparoscopic hepatic lobectomy was completed in all pigs without the use of specialized instruments and with a mean operative time of 179 +/- 9 min. No significant perioperative complications were observed. The average weight of each resected lobe was 180 +/- 51 g. Complete blood count as well as serum organics and enzyme levels normalized after about 2 weeks. During necropsy, adhesion of the hepatic raw surface to the gastric wall and omentum were observed. No other abnormalities were identified. This minimally invasive left hepatectomy technique in swine could serve as a useful model for investigating liver diseases and regeneration, and offer preclinical information to improve hepatobiliary surgical procedures.

Roles of DNA dependent protein kinase in silica-induced cyclin E and CDK2 expressions and cell cycle changes in human embryo lung fibroblasts / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the roles of DNA dependent protein kinase (DNA-PK)in silica-induced cell cycle changes and expressions of CyclinE and CDK2 in human embryo lung fibroblasts (HELF).</p><p><b>METHODS</b>The expressions of Ku80 and DNA-PKcs proteins were inhibited by siRNA plasmids, respectively. Flow cytometry was used to detect the distributions of cell cycle and western blot assay was used to determine the expression levels of CyclinE and CDK2 after cells were exposed to 200 microg/ml silica for 0, 3, 6, 12, 24 h.</p><p><b>RESULTS</b>The proportion of G1 phases in negative control cells decreased from 83.53% +/- 2.24% to 69.11% +/- 3.12% after exposure to silica; the proportion of G1 phases in H-Ku80 and H-PKcs cells exposed to silica decreased from 85.16% +/- 3.73% to 59.92% +/- 3.31% and from 75.06% +/- 2.23% to 58.32% +/- 1.35%, respectively (P < 0.05). The exposure to silica resulted in the increasing protein expression levels of CyclinE and CDK2 in negative control cells, and the expression levels of CyclinE were obviously suppressed in H-Ku80 and H-PKcs as compared with control cells. However, the expression level of CDK2 protein did not change significantly.</p><p><b>CONCLUSION</b>DNA-PK might play a role in silica-induced alternations of cell cycle and regulate silica-induced overexpression of CyclinE in human embryo lung fibroblasts.</p>

The roles of Ku80/p53 pathway in silica-induced cell cycle changes in human embryo lung fibroblasts / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the roles of Ku80/p53 pathway in silica-induced cell cycle changes in human embryo lung fibroblasts (HELF).</p><p><b>METHODS</b>Ku80 siRNA expression vectors were transfected into HELF by lipofectamine. Flow cytometry was used to detect the distributions of cell cycle and western blot assay was used to determine the expression level of Ku80, p53 and p21 proteins or the phosphorylation levels of p53-ser15 after cells were exposed to silica.</p><p><b>RESULTS</b>The expression levels of Ku80 protein increased in concentration-dependent and time-dependent manners after cells were exposed to silica. The proportion of G1 phases in H-NC cells (controls) decreased from 89.28% +/- 2.19% to 68.93% +/- 3.79% after exposure to silica, and the proportion of G1 phases in HELF cells (H-Ku80) decreased from 85.16% +/- 3.73% to 59.92% +/- 3.31% after exposure to silica (P<0.05). The expression levels of Ku80, p53 proteins or p21 proteins or phosphorylation level of p53-ser15 were obviously suppressed in H-Ku80, as compared with H-NC.</p><p><b>CONCLUSION</b>Ku80/p53 pathway plays a role in the cell cycle charges induced by silica in human embryo lung fibroblasts.</p>

Silica induce cell cycle changes by mitogen-activated protein kinases pathway / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the roles of mitogen-activated protein kinases (MAPK) on silica-induced cell cycle changes.</p><p><b>METHODS</b>After cells were treated with 200 microg/ml silica, Western blot and Immunofluorescence assays were utilized to detect the expression of cyclin D1, CDK4 and E2F-4, Flow cytometry was used to detect cell cycle progression, the dominant negative mutants techniques were used to investigate silica-induced signal pathway and the effects of which in silica-induced cell cycle changes.</p><p><b>RESULTS</b>After cells were exposed to 200 microg/ml silica 24 h, the results of present study showed the proportion of cells in G1 phases was decreased. Silica-induced cell cycle alternation was markedly impaired by stable expression of a dominant negative mutants of ERK or JNK, but not p38. It was found that ERK and JNK were involved in silica-induced cyclin D1 and CDK4 overexpression and the decreased expression of E2F-4.</p><p><b>CONCLUSION</b>ERK and JNK, but not p38, mediated silica-induced cell cycle changes in human embryo lung fibroblasts.</p>

The roles of activated protein-1 and cell cycle protein in silica-induced cell cycle changes / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the roles of cyclin D1 and CDK4 in the cell cycle changes of human embryonic lung fibroblasts (HELFs) exposed to silica.</p><p><b>METHODS</b>HELFs were divided into 4 groups: control group, curcumin (20 µmol/L for 1 h) group, silica (200 µg/ml for 24 h) group and curcumin plus silica group, i.e. after exposure to 20 µmol/L curcumin for 1h, the HELFs were treated with 200 µg/ml silica for 24 h. Western blot and Immunofluorescence assays were utilized to detect the expression levels of cyclin D1, CDK4 and E2F1/4. Flow cytometry was used to detect the cell cycle progression, the RNA transfection technique was used to investigate the silica-induced signal pathway and the roles of which in silica-induced cell cycle changes.</p><p><b>RESULTS</b>The expression levels of cyclin D1 and CDK4 significantly increased and the expression level of E2F-4 decreased obviously, but the expression level of E2F-1 did not significantly change in silica group. The proportion of G1 phase cells obviously decreased and the proportion of S phase cells significantly increased in silica group, as compared with control group (P < 0.05). When suppressing the expression of cyclin D1 or CDK4, the proportions of cells in G1 phase in anti-D1 plus silica group and anti-K4 plus silica group did not obviously change, as compared with control group. When suppressing AP-1 activity, the cyclin D1 and CDK4 expression levels decreased and the E2F-4 expression level increased in curcumin plus silica group, as compared with silica group.</p><p><b>CONCLUSION</b>The results of present suggested that 200 µg/ml silica could induce the high expression of cyclin D1 and CDK4 and the low expression of E2F-4, resulting in the cell cycle changes by AP-1/cyclin D1 pathway in HELFs.</p>

Influence of insulin resistance on long-term outcomes in patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Insulin resistance (IR) is significantly associated with coronary artery disease and cardiovascular events in patients with or without type 2 diabetes mellitus. This study aimed to evaluate the influence of IR on long-term outcomes of patients undergoing percutaneous coronary intervention (PCI) with sirolimus-eluting stent (SES) implantation.</p><p><b>METHODS</b>A total of 467 consecutive patients undergoing SES-based PCI were divided into IR group (n = 104) and non-IR group (n = 363). The patients were followed up for one year. The rate of major adverse cardiac events (MACEs) including death, non-fatal myocardial infarction and recurrent angina pectoris was compared by the log-rank test, and the independent risk factors were identified by the Cox regression analysis.</p><p><b>RESULTS</b>MACEs occurred more frequently, and cumulative survival rate was lower in the IR group than in the non-IR group during the follow-up (all P < 0.05). IR was an independent risk factor for the occurrence of cardiac death and non-fatal myocardial infarction (OR = 2.76, 95%CI = 1.35 - 5.47, P = 0.034). Old age, diabetes, and multi-vessel disease were determinants for recurrent angina pectoris after PCI (P < 0.05). Subgroup analysis revealed that IR (OR = 3.35, 95%CI = 1.07 - 13.59, P = 0.013) and multi-vessel disease (OR = 2.19, 95%CI = 1.01 - 5.14, P = 0.044) were independent risk predictors for recurrent angina pectoris in patients with diabetes after PCI.</p><p><b>CONCLUSIONS</b>IR is associated with reduced MACE-free survival and remains an independent predictor for recurrent angina pectoris after PCI with SES implantation.</p>

Roles of phosphatidylinositol 3 kinase in silica-induced DNA double strand breaks damage repair in human embryo lung fibroblasts / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the role of Phosphatidylinositol 3 kinase (PI3K) in silica-induced DNA double strand break repair in human embryo lung fibroblasts (HELF).</p><p><b>METHODS</b>Control HELF cells and DN-Deltap85 (HELF transfected with Dominant negative mutant of PI3K) were treated with 200 microg/ml silica for different times. The expression levels of phosphor-H2AX (H2AX), Ku70, Ku80 and DNA-PKcs were determined by Western blot. Furthermore, DNA double strand breaks were measured by neutral comet assay after cells were treated with 200 microg/ml silica for 0, 12 and 24 h.</p><p><b>RESULTS</b>After treatment with 200 microg/ml silica for different times, the levels of H2AX were increased in a time-dependent manner and the expression levels of H2AX were obviously suppressed in DN-Deltap85 compared with control cells. The levels of Ku70 and Ku80 were also significantly suppressed in DN-Deltap85 (0.37 +/- 0.14, 0.55 +/- 0.17) compared with control cells (0.58 +/- 0.09, 0.95 +/- 0.21) after treatment with 200 microg/ml silica for 12 h (P < 0.05). Both the percentage of tail DNA in HELF and DN-Deltap85 increased significantly at 12 h (9.78 +/- 1.15, 11.79 +/- 4.90) compared with groups without treatment with silica (2.40 +/- 0.69, 3.31 +/- 1.35) and then decreased at 24 h (4.19 +/- 0.47, 7.58 +/- 4.32), but only the decrease of HELF at 24 h was significant compared with HELF at 12 h (P < 0.05). DNA repair competence of HELF was 75.74% and that of DN-Deltap85 declined to 49.64%.</p><p><b>CONCLUSION</b>Silica dust can induce DNA double strand breaks in human embryo lung fibroblasts. PI3K might play a role in silica-induced DNA double strand break repair by regulating the expression levels of Ku70 and Ku80.</p>

Role of p53 in silica-induced cell cycle alternation and DNA double-strand break repair in human embryo lung fibroblasts / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the role of p53 in silica-induced cell cycle alternation and DNA double strand breaks repair in human embryo lung fibroblasts (HELF).</p><p><b>METHODS</b>Neutral comet assay was applied to detect silica-induced DNA double strand breaks. According to the neutral comet experimental result, the DNA repair competence was calculated. The expression levels and phosphorylation of protein in HELF were determined by Western blot. Cell cycle changes were identified by flow cytometry in HELF.</p><p><b>RESULTS</b>After treatment with 200 microg/ml silica for different times (0, 1, 2, 6, 12 and 24 h), the expression levels and phosphorylation of p53 increased in a time-dependent manner, reaching maximum at 12 h and then decreasing at 24 h. After treatment with 0, 25, 50, 100, 200, 300 and 400 microg/ml silica for 12 h, the expression levels and phosphorylation of p53 increased in concentration-dependent manner. After p53 expression was inhibited, silica-induced DNA damage repair competence was markedly increased (DRC = 87.68%), compared with the negative control cell induced by silica (DRC = 57.19%). Silica increased the percentage of S phase (31.8 +/- 1.1)% compared with the controls (24.3 +/- 3.8)% (P < 0.05). When p53 expression was inhibited, the number of S phase cells was significantly increased, (41.4 +/- 0.6)% compared with the controls (25.4 +/- 1.9)% (P < 0.05).</p><p><b>CONCLUSION</b>The silica dramatically increases the expression levels and phosphorylation of p53. The increased expression of p53 mediates silica-induced cell cycle change and inhibits silica-induced DNA double strand breaks repair.</p>