Lactate is considered a dead-end product of glycolysis.Its generation and accumulation promotes tumor growth and metastasis,and it is related to the poor prognosis of tumor.But recent studies have found,tumor cells can also uptake and utilize lactate.With the recent advances in tumor metabolism and gene therapy,lactate is a potential therapeutic target in tumors.

There has been no detailed reiport on the changes of the activity of serum glycylproline dipeptidyl aminopeptidase (GPDA) in patients with pancreatic career.Tn this paper,the serum level of GPDA was measured in 166 cases with various malignant and benign gastrointestinal diseases and 60 normal controls.It was found that the serum GPDA activity in patients with pancreatic cancer was 101,02?75.84u/L and significantly higher than that in the patients with pancreatitis and in the normal controls.There was a statistically significant difference of the GPDA activity value between the patients with malignant and benign pancreatic diseases.The elevation of GPDA activity was more marked in those patients with cancers in the head of the pancreas.In addition,the elevation of GPDA activity was dependent on the differentiation of cancer cells but not on the size of cancers.Significantly higher level of GPDA was also found in patients with hepatic carcinoma and carcinoma of ampulla of vater but significantly lower level in patients with gastric cancer.It is believed that the determination of serum GPDA activity might be helpful for the diagnosis of pancreatic cancer.

Objective To investigate the influence of individual factors and labor organization factors on work-related musculoskeletal disorders (WMSDs) in automobile manufacturing workers, and to provide a scientific basis for the prevention and treatment of WMSDs in automobile manufacturing workers. Methods In April 2020, 5564 workers in an automobile factory were selected by cluster sampling method. The prevalence of WMSDs was investigated by using the Musculoskeletal Disorders Questionnaire, and the influence of individual factors and labor organization factors on WMSDs was investigated by using generalized estimation equation. Results The prevalence rate of WMSDs was 79.00% (4396/5564), and the prevalence rate of multisite WMSDs was 67.95% (3781/5564). The analysis of generalized estimation equation showed that doing the same job every day (OR= 1.478, P < 0.05), age ≥40 years (OR=1.416, P< 0.05), personnel shortage (OR= 1.356, P < 0.05), and work length of 6～10 years and 11～15 years (OR= 1.349, P< 0.05) were the main risk factors for WMSDs in automobile manufacturing workers. Shift work and working time > 40 hours per week increased the risk of WMSDs (P< 0.05). Male and adequate rest time were protective factors for WMSDs. The job correlation matrix showed that WMSDs in most parts had a positive correlation. Conclusions The prevalence of multisite WMSDs of workers in automobile manufacturing industry is high, and unreasonable labor organization is the main risk factor of WMSDs. Appropriate work breaks can effectively reduce the risk of WMSDs, and effective intervention measures should be carried out to prevent the occurrence of WMSDs in workers in automobile manufacturing industry. The generalized estimation equation can better analyze the influencing factors of WMSDs.

Background Welders in automobile manufacturers are prone to hand/wrist musculoskeletal disorders (MSDs), which seriously affect workers' physical and mental health. Objective To investigate the factors influencing hand/wrist MSDs of welders in an automobile factory and the population attributable risk percentage (PARP). Methods Five branches of an automobile factory were selected by convenient sampling method, and all qualified welders in the selected branches were enrolled as research participants. The Chinese Musculoskeletal Disorders Questionnaire was used to collect information such as general characteristics of welders, presentation of MSDs in the wrists and hands, and selected ergonomic factors. Log-binomial model in the SAS program was used to calculate the prevalence ratio (PR) of each influencing factor and PARP. Results The prevalence rate of MSDs in the hands/wrists of welders in the automobile factory was 44.1% (345/782). The results of multiple analysis showed that female (PR=1.25, 95%CI: 1.10-1.44), being very tired after work (versus not tired, PR=2.22, 95%CI: 1.16-4.25), twisting wrists (PR=1.44, 95%CI: 1.19-1.74), insufficient operating space (PR=1.22, 95%CI: 1.07-1.40), and holding or pinching objects by hands (PR=1.58, 95%CI: 1.18-2.12) increased the risk of reporting hand/wrist MSDs symptoms. The PARP of major occupational risk factors was: holding or pinching objects by hands, 32.46%; twisting wrists, 21.50%; being very tired after work, 15.28%; and insufficient operating space, 8.18%. Conclusion The prevalence of MSDs symptoms in hands/wrists of welders in this automobile factory is high. Gender, holding or pinching objects by hands, twisting wrists, being very tired after work, and insufficient operating space are the factors affecting hand/wrist MSDs, among which holding or pinching objects by hands and twisting wrists are the priority intervention factors.

Objective To monitor the indoor radon concentration of urban residents in Shiyan, China, and to analyze the related influencing factors. Methods From April to July, 2019, RSKS standard detectors were used to measure the indoor radon concentration of 125 households in Shiyan, and the results were analyzed. Results The indoor radon concentration of residents in Shiyan showed a skewed distribution, ranging from 13.8 to 145 Bq/m³, and M (P₂₅,P₇₅) was 38.3 (29.0,62.0) Bq/m³. The estimated annual effective dose of radon and radon daughters from inhalation was 0.52-5.50 mSv, and M (P₂₅,P₇₅) was 1.45 (1.10, 2.36) mSv, which was consistent with literature. Building structure (H = 14.10, P < 0.001), floor (H = 24.41, P < 0.001), and geographical region (H = 8.963, P < 0.05) were influencing factors of indoor radon concentration, and the differences were significant. Conclusion The indoor radon concentration of urban residents in Shiyan is lower than the national standard limit. However, in daily life, it is still necessary to take appropriate measures to reduce the concentration of indoor radon as much as possible.

Aim To investigate the effect of colchicine on lipopolysaccharide (LPS) induced endothelial to mesenchymal transition (EndMT) in human umbilical vein vascular endothelial cells (HUVECs) and its related mechanisms. Methods The EndMT model was established by treating HUVECs with LPS. Cell proliferation rate was detected by CCK-8 assay, cytotoxicity was detected by LDH assay, and the optimal drug concentration was screened. The cells were divided into the normal control group, the normal control + colchicine (10 nmol • L) group, the LPS (10 mg • L) model group, and the LPS + colchicine (10 nmol • L) group. The morphologic changes of the cells were observed under an inverted microscope, the cell migration ability was detected by Transwell assay, and the ability of tube formation was analyzed by tube formation assay. The expression of endothelial markers (CD31/ VE-cadherin) and mesenchymal cell markers (a-SMA/FSP-1) were detected by Western blot. NF-KB inhibitor was used to detect the changes in related signaling pathways. Results CCK-8 and LDH experiments showed that 10 nmol • L colchicine was the optimal concentration. LPS could induce morphological changes in HUVECs, and colchicine could reverse morphological changes in HUVECs to a certain extent. Transwell experiment showed that the migration ability of HUVECs in the LPS treatment group was significantly enhanced (P < 0. 05), and colchicine could significantly reverse this phenomenon (P < 0. 05) . Tube formation experiment showed that LPS decreased the endothelial tube formation ability of HUVECs (P < 0. 05), while colchicine treatment markedly improved LPS-induced tube formation defects (P < 0. 05) . Western blot assay showed that after colchicine co-cultured with LPS, the expression levels of CD31 and VE-cadherin significantly increased compared with the model group (P < 0. 05), while the expression levels of a-SMA and FSP-1 significantly decreased compared with the model group (P < 0. 05) . During the induction of EndMT by LPS, colchicine could inhibit the activation of the NF-KB/Snail signaling pathway. Conclusions Colchicine can effectively inhibit EndMT induced by LPS, and the mechanism may be related to the regulation of the NF-KB/Snail signaling pathway.

Objective: To investigate the influencing factors and population attributable risk percent (PAR%) of low back pain in automobile assemblers. Methods: A total of 634 assemblers from 11 automobile manufacturers in Shiyan City, Hubei Province were chosen as research subjects using judgment sampling method. The prevalence of low back pain in the past one year was investigated using Musculoskeletal Disorders Questionnaire. PAR% was used to analyze the contribution of influencing factors to low back pain. Results: The annual prevalence of low back pain was 68.8%. The results of multivariate logistics regression showed that length of service>15 years, high school or secondary college education or above, standing most of the time, sitting most of the time, the proportion of cumulative time of poor posture in work shift time ≥1/8, and bending for insufficient height of working space were the risk factors for low back pain (all P<0.05). The PAR% of the proportion of cumulative time of poor posture in work shift time ≥1/8 was 43.0%, 37.8% for standing most of the time, and 12.8% for bending for insufficient height of working space. Conclusion: The annual prevalence of low back pain was higher in automobile assemblers. The influencing factors included individual factors and occupational factors. The proportion of cumulative time of poor posture in work shift time ≥1/8, standing most of the time and bending for insufficient height of working space should be taken as the priority intervention factors to reduce the prevalence of low back pain among assemblers in this enterprise.

Objective To investigate the expression of oncogene C-erbB-2 and its significance in colorectal carcinoma. Methods Immunohistological EnVision staining was used to detect the expression of C-erbB-2 in 171 colorectal carcinoma, and 15 normal colorectal tissues were taken as controls. Results The positive percentages of C-erbB-2 in colorectal carcinoma and normal colorectal tissues were 23.4 % (40/171)and 0, which was significantly different (P ＜0.05). Only 5 samples showed strong positive expression (++ and +++) on epicyte, no relationship was found between C-erbB-2 expression and patients' gender, tumor differentiation, tumor stage, vascular and lymph node involvement, etc(P ＞0.05). The five year survival rate were 69.5 % (91/131) and 65.0 % (26/40) of C-erbB-2 negative and positive expression, the difference was not statistical (P ＞0.05). Conclusion There was on significant association between C-erbB-2 expression and clinicopathologic characteristics of colorectal carcinoma. C-erbB-2 did not present prognostic value in colorectal carcinoma.

Objective To investigate the value of the intraoperative real-time three-dimensional transesophageal echocardiography (RT 3D-TEE) in therapeutic application of surgery for the mitral valve prolapse.Methods Thirty-five patients underwent surgical treatment were diagnosed as mitral valve prolapse by 2-dimensional transthoracic echocardiography (2D-TTE),with or without ruptured chordae tendineae.RT 3D-TEE was performed for assessing the segment of prolapse and its complications before cardiopulmonary bypass and after heart resuscitation respectively.The echocardiographic results were compared with the surgical findings.Results The accuracy of RT 3D-TEE to identify segments with prolapse was significantly higher than that of 2D-TTE (91.4％ vs 82.9％,P =0.003).RT 3D-TEE was more accurate than 2D-TTE for identifying ruptured chordae tendineae,vegetation and thrombus since higher sensitivity,specificity and Youden index.Among all 35 patients,valvuloplasty was performed in 28 cases,whereas,only 7 cases underwent replacement of prosthetic valves.Three patients were benefited by accurate evaluation of therapeutic effect using RT 3D-TEE in time.ConclusionsIntraoperative RT 3D-TEE can be used to provide “ surgical view”,acquired adequate valuable information of mitral valve,and more reliable functional and anatomical assessment of the mitral valve components and its geometry.Suitable surgical intervention can be designed for improving outcomes of patients.

Objective To investigate the clinical value of double contrast-enhanced ultrasonography (DCEUS) in assessing the peripancreatic vascular invasion of pancreatic carcinoma.Methods Twenty-eight patients with pancreatic cancer confirmed by postoperative pathology were examined by DCEUS preoperatively.The relationship between neoplasms and peripancreatic vessels was analyzed for assessing whether vascular invasion of pancreatic cancer had occurred.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of DCEUS in evaluating vascular involvement were calculated by using the surgical results as a gold standard.Kappa test was used for assessing the intra- and interobserver reliability of DCEUS.Results In total 28 patients,21 cases were diagnosed as vascular invasion,whereas,7 cases were noninvasive by surgical results.By DCEUS,18 cases were assessed as positive involvement of vessels,whereas,10 cases were negative.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of DCEUS in evaluating vascular involvement were 85.71 ％,100％,100 ％,70.00 ％ and 89.29 ％ respectively,and with higher reliability (Kappainter =0.75,Kappa =0.80).Conclusions DCEUS could be considered as a novel method to assess vascular invasion of pancreatic carcinoma accurately and reliably.