Objective To investigate the therapeutic effects of bone marrow mesenchymal stem cells (BMSCs) for radiation-induced lung injury (RILI) and the underlying mechanism. Methods Forty-five healthy adult male C57BL/6 mice were randomly divided into control, model, and BMSCs groups. The model and BMSCs groups received a single irradiation dose of 20 Gy to the chest, while the control group did not receive X-ray irradiation. For the BMSCs group, an injection of 1 × 10⁶ BMSCs cells was administered via the tail vein within 6 h after irradiation. In the 5th week, the lung tissue was taken to observe pathological changes with HE staining; examine the expression of the inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) with immunohistochemical staining; observe the polarization of macrophages with immunofluorescence staining; and measure the expression of the epithelial-mesenchymal transition markers E-cadherin, N-cadherin, and vimentin proteins by Western blot. Results After radiation, the model group developed pulmonary vasodilation and congestion with septal thickening and inflammatory cell infiltration, and these changes were markedly reduced in the BMSCs group. The model group showed significantly down-regulated expression of IL-6 and TNF-α compared with significantly increased levels in the model group (P < 0.01, P < 0.05). Treatment with BMSCs significantly increased the polarization of lung macrophages towards the M2 type, while significantly decreasing the abnormally increased N-cadherin and vimentin levels in RILI mice (P < 0.05, P < 0.01). Conclusion BMSCs have therapeutic effects for RILI mice, which may be through promoting macrophage polarization from M1 to M2.

To revise GBZ 188 Technical Specification for Occupational Health Surveillance based on national laws, regulations, standards, specifications and legal documents of occupational disease, and combination with the actual situation in China. The main modifications are as follows: the occupational health surveillance for workers exposed to toluene (xylene may implement by reference), bromopropane, methyl iodide, ethylene oxide, chloroacetic acid, indium and its compounds, coal tar, coal tarasphalt, asphalt, β-naphthylamine, dust of metal and its compounds(tin, iron, antimony, barium and its compounds), hard metal dust, erionite dust, low temperature, laser, tick-borne encephalitis virus, Borrelia burgdorferi, and human immunodeficiency virus, for scraper or grind operators, and underground workers using squatting or kneeling position, crawling position, side-lying position, or shoulder position for a long period of time are included. The emergency health screening for workers exposed to arsenic, fluorine and its inorganic compounds, and acrylamide are included. The occupational medical examination (OME) for workers exposed to amino and nitro compounds of benzene, phosgene, monomethylamine, organic fluorine and dimethyl sulfate has been adjusted and made mandatory, with corresponding assessments required upon leaving the job. The special occupational health surveillance for workers exposed to mycobacterium tuberculosis and hepatitis virus is removed. The OME conclusion of reexamination is removed, and standardize recheck/additional inspection requirements. The optional items in OME performed before, during and after leaving post are removed, but the optional items in emergency medical examination are retained. Additional OME items are added. The Guideline for OME Summary Reports is added as informative appendix, and so on. The revised GBZ 188 Technical Specification for Occupational Health Surveillance is more scientific and practical.

Objective:To verify and discuss the consistency and applicability of the semi empirical formula and Monte Carlo simulation method in the radiation shielding calculation for high energy synchrotron radiation source.Methods:The semi empirical formula and Monte Carlo simulation were used to calculate the ambient dose equivalent outside of the shielding.Results:The ratio of Jenkins semi empirical formula result to Monte Carlo simulation result was 111%-153%. The ratio of Sakano semi empirical formula result to Monte Carlo simulation result was 201%.Conclusions:For a single shielding material, the semi empirical formula can be simple and conservative to complete the shielding calculation for high-energy electron accelerator. For a variety of shielding materials, Monte Carlo simulation method should be used.

Objective: To investigate the duration of Norovirus (NoV) shedding among infected school children during a NoV outbreak in a kindergarten,and to provide scientitic basis for epidemic prevention and control. Methods: Specimens and epidemiological data were collected from suspected cases, and specimens were detected using real-time RT-PCR to determine whether or not infecting with NoV. Specimens were collected every 3-7 days from NoV-infected children until specimens became negative for NoV. Results: A total of 14 suspected cases were reported, and 12 of them were infected with NoV. The average duration of NoV shedding was (26.58±17.94)d. The specimens among 9 from 12 Nov-infected cases were positive at 7 days, 8 NoV-intected cased remained positive at 14 days and 7 Non-infected cased at least 21 days. Conclusion Since NoV shedding duration among NoV-infected children tends to longer than their isolation time during outbreaks, reinforcement of hygiene practices among these school children is especially necessary to reduce the risk of virus secondary transmissions after their return to school.

Objective:To improve the precision and accuracy of gross radioactivity detection in water, and to improve the radiological health and environmental monitoring level of each laboratory, it is necessary to carry out method verification and quality control.Methods:The thick source method for gross α and the thin source method for gross β analysis were used to analyze the actual samples. After multiple tests, the precision of the detection was calculated. Through the spike recovery test and the comparison sample analysis of the national radiological health in 2019, the accuracy analysis of the method was performed.Results:In the precision experiment, the relative standard deviations of the gross α and gross β results were 23% and 13%, respectively. The three spike recoveries were 103.1%, 103.5%, and 105.8%, respectively. The relative errors of gross α and gross β compared with the reference value were 0.92% and 9.4%, respectively. All the result reflected the high accuracy of the method .Conclusions:The relative standard deviations, recoveries, and relative errors in the method validation and quality control were below the limits of the criterion. This work systematically discussed the major factors that may cause errors in the detection, which could further improve the level of radiological health and environmental monitoring.

Objective:To investigate the role of preoperative 18F-fluorodeoxyglucose (FDG) PET/CT imaging in mid-long-term prognosis of patients with resectable non-small cell lung cancer (NSCLC). Methods:Seventy resectable NSCLC patients (35 males, 35 females, median age 64 years) in Beijing Hospital between April 2010 and August 2016 were enrolled into this retrospectively study. All patients underwent 18F-FDG PET/CT imaging followed by pulmonary resection with mediastinal or hilar lymph nodes dissection within 1 month. The findings of PET/CT imaging including characteristics of primary lesions and mediastinal or hilar lymph nodes (size and maximum standardized uptake value (SUV max) of primary lesion, SUV max and distribution of high metabolic lymph nodes (HML)) were analyzed, and patients were followed up. Survival outcome indicators were defined as overall survival (OS) and progression-free survival (PFS). Survival analysis was conducted by Kaplan-Meier method, log-rank method and Cox proportional hazard models to assess the predictive factors. Results:Patients were followed up for 0.9-8.2 years. Among 70 patients, 31.4% (22/70) had disease progression and 24.3% (17/70) died. As for OS, there were significantly differences between patients with SUV max of primary lesion≥10 and <10 (4.6 vs 7.6 years), with size of primary lesion >3 cm and ≤3 cm (4.8 vs 7.4 years), with unilateral mediastinal or hilar HML and bilateral sides or without HML (4.4 vs 7.4 years), with SUV max of mediastinal or hilar lymph nodes ≥5.0 and <5.0 (3.8 vs 7.3 years) ( χ2 values: 10.135-15.238, all P<0.01), as well as PFS (3.9 vs 6.7, 3.8 vs 6.6, 3.8 vs 6.4, 3.3 vs 6.3 years; χ2 values: 8.410-14.600, all P<0.01). Cox multivariate analysis demonstrated that the size and SUV max of primary lesion were independent predictive factors of OS and PFS (all P<0.01). Moreover, the distribution of mediastinal or hilar HML had marginal significance in predicting OS ( P=0.051). Conclusions:Size and SUV max of primary lesion in preoperative 18F-FDG PET/CT imaging are predictive factors for the survival of postoperative NSCLC. The distribution of the mediastinal or hilar HML may have significance for the survival prediction of postoperative NSCLC.

Objective: To compare the clinical effects of laparoscopic repair and open repair of gastroduodenal ulcer perforation. Methods: Retrospective analysis was performed on 117 patients with perforated gastroduodenal ulcer admitted to Sijing Hospital of Shanghai Songjiang District from October 2005 to February 2018, including 86 males and 31 females. The average age was 35.56 years with a range from 17 to 68 years. Patients were divided into two groups according to different surgical methods: laparoscopic group (n=56) and open group (n=61). Patients in the laparoscopic group were received laparoscopic repair for perforated gastroduodenal ulcer, while patients in the open group received open repair for perforated gastroduodenal ulcer. Comparison of two groups of patients with operation time, intraoperative blood loss, postoperative first anal exhaust time, analgesic utilization rate, length of hospital stay, the body′s inflammatory response [preoperative and 24 h, 72 h, 120 h of postoperative peripheral white blood cell (WBC)], C-reactive protein level (CRP), postoperative complications (postoperative incision infection, incision dehiscence, gastric duodenal fistula, abdominal abscess, adhesion intestinal obstruction and lung infection). Measurement data were expressed as mean±standard deviation (Mean±SD), and t-test was used for comparison between groups; count data were compared by Chi-square test. Results: All the patients in the two groups successfully completed the operation, and there were no cases transferred to laparotomy in the laparoscopic group. Intraoperative blood loss[(15.3±9.5) ml vs (30.5±11.3) ml, P<0.001], time of first anal exhaust[(56.5±9.8) h vs (83.8±15.6) h, P<0.001], analygesic utilization rate (10.71% vs 52.46%, P<0.005), and length of hospital stay [(7.5±1.5) d vs (10.0±3.4) d, P<0.001] of the laparoscopic group were significantly better in the open group, the differences were statistically significant. The WBC and CRP at 24 h, 72 h and 120 h after surgery of the laparoscopic group were also significantly better than in the open group [WBC: 24 h, (14.55±3.44) ×10⁹/L vs (16.02±4.12) ×10⁹/L, P=0.020; 72 h, (10.25±2.32) ×10⁹/L vs (14.22±3.29) ×10⁹/L, P<0.001; 120 h, (8.12±3.11)×10⁹/L vs (11.58±2.33) ×10⁹/L, P<0.001. CRP: 24 h, (50.35±13.73) mg/L vs (80.11±13.56) mg/L, P<0.001; 72 h, (29.37±7.81) mg/L vs (53.57±8.05) mg/L, P<0.001; 120 h, (17.71±7.01) mg/L vs (34.35±7.72) mg/L, P<0.001], the differences were statistically significant. There was no significant difference in operation time and postoperative complications between the two groups (P>0.05). Conclusion Compared with open gastroduodenal ulcer perforation repair, laparoscopic gastroduodenal ulcer perforation repair surgery trauma are smaller, and the body′s inflammatory response are lighter, postoperative complications is no statistical significance, but will look from actual data, the cases of complications is less, is now a better surgical treatment of gastroduodenal ulcer perforation.

Objective: To determine the positional relationship between impacted mandibular third molar(IMTM) and mandibular canal(MC) by CBCT. Methods: 664 IMTMs with root apexes contacted to MCs on panoramic radiograph were further examined by CBCT,the exact positional relationship between IMTMs and MCs was observed and analyzed by I-Dixel software. Results: The 664 cases were divided into lowly(6. 3％),intermediately(60. 7％) and highly(33. 0％) impacted groups by the depth of IMTMs in mandibulae showed on CBCT images. The distance(mm) from the root apexes of IMTMs to the intact superior wall of MCs(n = 329) in lowly, intermediately and highly impacted cases were 1. 39 ± 1. 38,1. 28 ± 1. 03 and 1. 79 ± 1. 54 respectively(P ＜ 0. 05). MCs on the buccal side,lingual side,under the IMTMs and between the root apexes were found in 49. 8％,12. 0％,36. 6％ and 1. 5％ of the cases; the MC wall deffect was found in 65. 8％,27. 5％ and 95. 0％ of the cases with the MCs under,on buccal and lingual side of the IMTMs, respectively(P ＜ 0. 001). Conclusion: CBCT examination is necessary for the determination of the positional relationship between MC canal and IMTM with the root apex cotacted or overlapped to MC.

Objective To evaluate the role of M3 receptors in penehyclidine hydrochloride ( PHC)-induced reduction of lipopolysaccharide ( LPS)-induced injury to human pulmonary microvascular endotheli-al cells ( PMVECs) . Methods Human PMVECs transfected with M3 shRNA were seeded in 6-well plates (2 ml∕hole) or in culture flasks (4 ml∕flask) at the density of 1×105 cells∕ml and divided into 5 groups ( n=5 each) using a random number table method: control group ( group C) , LPS group, PHC plus LPS group ( group P+LPS) , LPS plus M3 shRNA transfection group ( group LPS+shRNA) , and PHC plus LPS plus M3 shRNA transfection group ( group P+LPS+shRNA) . Group C received no mediation, and LPS was added at the final concentration of 0. 1 μg∕ml in the other groups. PHC 2 μg∕ml was added at 1 h before adding LPS in P+LPS and P+LPS+shRNA groups. The cells were transfected with plasmid containing 2. 5 nmol∕L M3 receptor shRNA in LPS+shRNA group and P+LPS+shRNA group. Contents of filamentous actin ( F-actin) in endothelial cells were measured by flow cytometry at 1 h after adding LPS. The expression of myosin light chain kinase ( MLCK) and VE-cadherin protein was examined by immunofluorescence. The ex-pression of nuclear factor kappa B ( NF-κB) p65 and IκB was detected by Western blot. Contents of tumor necrosis factor-alpha ( TNF-α) and interleukin-6 ( IL-6) were determined by enzyme-linked immunosorbent assay. The M3 receptor mRNA transcription was detected by real-time polymerase chain reaction at 10, 30 and 60 min after adding LPS. Results Compared with group C, F-actin content was significantly de-creased, the expression of VE-cadherin and IκB was down-regulated, the contents of TNF-αand IL-6 were increased, and the expression of MLCK and NF-κB p65 was up-regulated in LPS and P+LPS groups ( P<0. 05) . Compared with group C, the expression of M3 receptor mRNA was significantly up-regulated in group LPS ( P<0. 05) , and no significant change was found in group P+LPS ( P>0. 05) . Compared with group LPS, F-actin content was significantly increased, the expression of VE-cadherin and IκB was up-reg-ulated, the contents of TNF-αand IL-6 were decreased, and the expression of MLCK, NF-κB p65 and M3 receptor mRNA was down-regulated in group P+LPS and group LPS+shRNA ( P<0. 05) . Compared with group P+LPS, F-actin content was significantly increased, the expression of VE-cadherin and IκB protein was up-regulated, TNF-α and IL-6 contents were decreased, and the expression of MLCK, NF-κB p65 and M3 receptor mRNA was down-regulated in group P+LPS+shRNA ( P<0. 05) . Conclusion PHC re-duces LPS-induced injury to human PMVECs through interfering with M3 receptors and inhibiting NF-κB-mediated inflammatory responses.

BACKGROUND:Along with the widespread application of biodegradable materials in the field of medicine and the in-depth research of biomechanics,the drawbacks of traditional medical metal materials are increasingly appearing.In recent years,researchers at home and abroad focus on biodegradable materials that are represented by high molecular polymer to seek new breakthroughs in the field of spinal instability.OBJECTIVE:To investigate biomechanical changes of polylactic acid-polyglycolic acid (PLGA) lumbar interbody fusion cage in the body and discusses its feasibility for treating segmental instability of the spine.METHODS:Forty-two healthy pigs (9 months old) were randomly divided into two groups (n=21),and L4/5 intervertebral disc nucleus pulposus was removed in all animals.In experimental group,PLGA lumbar interbody fusion cage filled with broken bone was implanted;and in control group,autologous bone was implanted.X-ray was performed to observe the fusion of operation segments at 4,12 and 72 weeks postoperatively.Feasibility of fibrous fusion was measured by biomechanical test.Histologically,bone graft fusion at the surgical site and material degradation were detected.RESULTS AND CONCLUSION:(1) Imaging examination:Bone graft fusion in two groups was not visible at 4 weeks after operation.Evidence of increasing fusion was found in the experimental group at 12 weeks after operation;a visible part of the bone bridge was found in the control group,in which there was one case of fusion.Degradation of the fusion cage with one case of fusion in experimental group was found after 72 weeks after operation,and two cases of fusion in the control group.(2) Biomechanical test:There was no difference in the spinal range of motion between the two groups in different states at 4 weeks after operation (P ＞ 0.05).The spinal range values of motion at most of the states at 72 weeks after operation were significantly lower than those at 4 weeks after operation.(3) Cell histology observation:With the passage of time,the materials in the experimental group degraded gradually;new bone grew slowly and then fast,with bone fusion step by step.Fusion results were similar in the two groups.Our experimental findings indicate that the PLGA lumbar fusion cage has good biocompatibility.In addition to the individual state (left flexion),the mechanical properties of the fusion cage are similar to that of autogenous bone,and the fusion cage enables the segmental reconstruction of the pig spine to the maximum extent.