Objective To study endothelial damage by observing changes of circulating endothelial cells (CECs) in blood, coagula-tion and fibrinolysis index in patients with acute respiratory distress syndrome. Methods CECs were ...Objective To study endothelial damage by observing changes of circulating endothelial cells (CECs) in blood, coagula-tion and fibrinolysis index in patients with acute respiratory distress syndrome. Methods CECs were separated by isopycnic centrifugation method in 14 patients with acute lung injury (ALI), 7 patients with acute respiratory distress syndrome (ARDS), 10 intensive care unit (ICU) controls, and 15 healthy controls. Plasma prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FG), fibrin degradation products (FDP), and D-dimer were examined simultaneously. Acute physiology and chronic health evaluation (APACHE)Ⅱand lung injury score (LIS) were recorded to evaluate severity of illness and lung injury. Results (1) The number of CECs in ALI (10.4 ±2.3) and ARDS groups (16.1 ±2.7) was higher than that in the healthy (1.9 ±0.5) (P< 0.01). In both ALI and ARDS, the number of CECs correlated with APACHEⅡ(r=0.55, P< 0.05 and r=0.62, P< 0.05, respectively)and LIS (r=0.60, P< 0.05 and r=0.53, P< 0.05, respectively). CEC number was negatively correlated with PaO 2 in ALI and ARDS (r=-0.49, P< 0.05 and r=-0.64, P< 0.05, respectively). (2) The level of FDP and D-dimer were higher in ALI and ARDS patients than that in ICU and healthy control groups (P< 0.05). The level of FG in ARDS group was significantly higher than in the ICU and healthy control groups (P< 0.05). But in ALI group, the level of FG was significantly higher than only healthy control group (P< 0.05). Conclusions Endothelial cell damage occurs in ARDS patients, which may play a major role in the pathophysiology of ARDS. Changes of endothelial cell activation and damage markers, such as CECs, plasma coagulation and fibrinolysis index, to some extent reflect severity of illness and lung injury in ARDS.展开更多
Purpose： The aims of this study were to assess differences of limb symmetry index （LSI） in strength- and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related pe...Purpose： The aims of this study were to assess differences of limb symmetry index （LSI） in strength- and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related performance levels and to prospectively assess limb differences as a possible risk factor for traumatic and overuse injury in youth ski racers. Methods： The study （Study 1） included 285 high-level competitive ski racers （125 females, 160 males） of 3 age-related performance levels and based on the school system： 95 youth （10-14 years, secondary modem school）, 107 adolescent （15-19 years, grammar school）, and 83 elite athletes （20-34 years）. To investigate the second aim （Study 2）, 67 of the 95 youth athletes were included and any traumatic or overuse injuries were prospectively recorded over 2 seasons. All athletes performed 4 unilateral tests （strength related： one-leg counter movement jump （OL-CMJ） and one-leg isometric/isokinetic press strength test （OL-ILS）; coordination related： one-leg stability test （OL-ST） and one-leg speedy jump test （OL-SJ））. The LSI was calculated by dividing the dominant leg by the nondominant leg and multiplying by 100. Kruskal-Wallis H tests and binary logistic regression analyses were conducted. Results： There were significant differences between the LSI of the 3 age-related performance-level groups only in the strength-related tests： the OL-CMJ （X^2（2, 285） = 9.09; p = 0.01） and the OL-ILS （X^2（2,285） = 14.79; p 〈 0.01）. The LSI for OL-ILS was found to be a significant risk factor for traumatic injury in youth ski racers （Wald = 7.08; p 〈 0.01）. No significant risk factors were found for overuse injuries. Conclusion： Younger athletes display slightly greater LSI values only in the strength-related tests. The cut-off value of limb differences of 〈 10% for return to sport decisions seems to be appropriate for elite athletes, but for youth and adolescent athletes it has to be critically discussed. It seems to be necessary to define thresholds based on specific performance tasks （strength vs. coordination related） rather than on generalizations, and age-related performance levels must be considered. Limb differences in unilateral leg extension strength represent a significant injury risk factor in youth ski racers.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.展开更多
After peripheral nerve injury, intraperitoneal injection of folic acid improves axon quantity, increases axon density and improves electromyography results. However, the mechanisms for this remain unclear. This study ...After peripheral nerve injury, intraperitoneal injection of folic acid improves axon quantity, increases axon density and improves electromyography results. However, the mechanisms for this remain unclear. This study explored whether folic acid promotes peripheral nerve injury repair by affecting Schwann cell function. Primary Schwann cells were obtained from rats by in vitro separation and culture. Cell proliferation, assayed using the Cell Counting Kit-8 assay, was higher in cells cultured for 72 hours with 100 mg/L folic acid compared with the control group. Cell proliferation was also higher in the 50, 100, 150, and 200 mg/L folic acid groups compared with the control group after culture for 96 hours. Proliferation was markedly higher in the 100 mg/L folic acid group compared with the 50 mg/L folic acid group and the 40 ng/L nerve growth factor group. In Transwell assays, the number of migrated Schwann cells dramatically increased after culture with 100 and 150 mg/L folic acid compared with the control group. In nerve growth factor enzyme-linked immunosorbent assays, treatment of Schwa nn cell cultures with 50, 100, and 150 mg/L folic acid increased levels of nerve growth factor in the culture medium compared with the control group at 3 days. The nerve growth factor concentration of Schwann cell cultures treated with 100 mg/L folic acid group was remarkably higher than that in the 50 and 150 mg/L folic acid groups at 3 days. Nerve growth factor concentration in the 10, 50, and 100 mg/L folic acid groups was higher than that in the control group at 7 days. The nerve growth factor concentration in the 50 mg/L folic acid group was remarkably higher than that in the 10 and 100 mg/L folic acid groups at 7 days. In vivo, 80 μg/kg folic acid was intraperitoneally administrated for 7 consecutive days after sciatic nerve injury. Immunohistochemical staining showed that the number of Schwann cells in the folic acid group was greater than that in the control group. We suggest that folic acid may play a role in improving the repair of peripheral nerve injury by promoting the proliferation and migration of Schwann cells and the secretion of nerve growth factors.展开更多
The movement of the wood skidding means on the natural ground causes damages in the soil and in the remaining stand, the size of which depends on the kind, the resistance and the soil conditions, from the size and mov...The movement of the wood skidding means on the natural ground causes damages in the soil and in the remaining stand, the size of which depends on the kind, the resistance and the soil conditions, from the size and movements frequency on the machines as well as from the length of the skidding wood. This study was carried out in a productive forest of Greece, the resistance of the soil in connection with the moisture and the category of the native stone, the pressure that tires of tractors exert in the soil, are estimated. It also estimated the percentage of the trees in the remaining stand which suffer damages from the movement of various means. The above means are used for the skidding of wood of different lengths. According to the results of the research some measures are suggested so as to decrease the damages, which are caused in the soil and in the remaining stand.展开更多
文摘Objective To study endothelial damage by observing changes of circulating endothelial cells (CECs) in blood, coagula-tion and fibrinolysis index in patients with acute respiratory distress syndrome. Methods CECs were separated by isopycnic centrifugation method in 14 patients with acute lung injury (ALI), 7 patients with acute respiratory distress syndrome (ARDS), 10 intensive care unit (ICU) controls, and 15 healthy controls. Plasma prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FG), fibrin degradation products (FDP), and D-dimer were examined simultaneously. Acute physiology and chronic health evaluation (APACHE)Ⅱand lung injury score (LIS) were recorded to evaluate severity of illness and lung injury. Results (1) The number of CECs in ALI (10.4 ±2.3) and ARDS groups (16.1 ±2.7) was higher than that in the healthy (1.9 ±0.5) (P< 0.01). In both ALI and ARDS, the number of CECs correlated with APACHEⅡ(r=0.55, P< 0.05 and r=0.62, P< 0.05, respectively)and LIS (r=0.60, P< 0.05 and r=0.53, P< 0.05, respectively). CEC number was negatively correlated with PaO 2 in ALI and ARDS (r=-0.49, P< 0.05 and r=-0.64, P< 0.05, respectively). (2) The level of FDP and D-dimer were higher in ALI and ARDS patients than that in ICU and healthy control groups (P< 0.05). The level of FG in ARDS group was significantly higher than in the ICU and healthy control groups (P< 0.05). But in ALI group, the level of FG was significantly higher than only healthy control group (P< 0.05). Conclusions Endothelial cell damage occurs in ARDS patients, which may play a major role in the pathophysiology of ARDS. Changes of endothelial cell activation and damage markers, such as CECs, plasma coagulation and fibrinolysis index, to some extent reflect severity of illness and lung injury in ARDS.
文摘Purpose： The aims of this study were to assess differences of limb symmetry index （LSI） in strength- and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related performance levels and to prospectively assess limb differences as a possible risk factor for traumatic and overuse injury in youth ski racers. Methods： The study （Study 1） included 285 high-level competitive ski racers （125 females, 160 males） of 3 age-related performance levels and based on the school system： 95 youth （10-14 years, secondary modem school）, 107 adolescent （15-19 years, grammar school）, and 83 elite athletes （20-34 years）. To investigate the second aim （Study 2）, 67 of the 95 youth athletes were included and any traumatic or overuse injuries were prospectively recorded over 2 seasons. All athletes performed 4 unilateral tests （strength related： one-leg counter movement jump （OL-CMJ） and one-leg isometric/isokinetic press strength test （OL-ILS）; coordination related： one-leg stability test （OL-ST） and one-leg speedy jump test （OL-SJ））. The LSI was calculated by dividing the dominant leg by the nondominant leg and multiplying by 100. Kruskal-Wallis H tests and binary logistic regression analyses were conducted. Results： There were significant differences between the LSI of the 3 age-related performance-level groups only in the strength-related tests： the OL-CMJ （X^2（2, 285） = 9.09; p = 0.01） and the OL-ILS （X^2（2,285） = 14.79; p 〈 0.01）. The LSI for OL-ILS was found to be a significant risk factor for traumatic injury in youth ski racers （Wald = 7.08; p 〈 0.01）. No significant risk factors were found for overuse injuries. Conclusion： Younger athletes display slightly greater LSI values only in the strength-related tests. The cut-off value of limb differences of 〈 10% for return to sport decisions seems to be appropriate for elite athletes, but for youth and adolescent athletes it has to be critically discussed. It seems to be necessary to define thresholds based on specific performance tasks （strength vs. coordination related） rather than on generalizations, and age-related performance levels must be considered. Limb differences in unilateral leg extension strength represent a significant injury risk factor in youth ski racers.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.
基金supported by the High Levels of Health Technical Personnel in Beijing City Health System of China,No.2013-3-050(to JZY)
文摘After peripheral nerve injury, intraperitoneal injection of folic acid improves axon quantity, increases axon density and improves electromyography results. However, the mechanisms for this remain unclear. This study explored whether folic acid promotes peripheral nerve injury repair by affecting Schwann cell function. Primary Schwann cells were obtained from rats by in vitro separation and culture. Cell proliferation, assayed using the Cell Counting Kit-8 assay, was higher in cells cultured for 72 hours with 100 mg/L folic acid compared with the control group. Cell proliferation was also higher in the 50, 100, 150, and 200 mg/L folic acid groups compared with the control group after culture for 96 hours. Proliferation was markedly higher in the 100 mg/L folic acid group compared with the 50 mg/L folic acid group and the 40 ng/L nerve growth factor group. In Transwell assays, the number of migrated Schwann cells dramatically increased after culture with 100 and 150 mg/L folic acid compared with the control group. In nerve growth factor enzyme-linked immunosorbent assays, treatment of Schwa nn cell cultures with 50, 100, and 150 mg/L folic acid increased levels of nerve growth factor in the culture medium compared with the control group at 3 days. The nerve growth factor concentration of Schwann cell cultures treated with 100 mg/L folic acid group was remarkably higher than that in the 50 and 150 mg/L folic acid groups at 3 days. Nerve growth factor concentration in the 10, 50, and 100 mg/L folic acid groups was higher than that in the control group at 7 days. The nerve growth factor concentration in the 50 mg/L folic acid group was remarkably higher than that in the 10 and 100 mg/L folic acid groups at 7 days. In vivo, 80 μg/kg folic acid was intraperitoneally administrated for 7 consecutive days after sciatic nerve injury. Immunohistochemical staining showed that the number of Schwann cells in the folic acid group was greater than that in the control group. We suggest that folic acid may play a role in improving the repair of peripheral nerve injury by promoting the proliferation and migration of Schwann cells and the secretion of nerve growth factors.
文摘The movement of the wood skidding means on the natural ground causes damages in the soil and in the remaining stand, the size of which depends on the kind, the resistance and the soil conditions, from the size and movements frequency on the machines as well as from the length of the skidding wood. This study was carried out in a productive forest of Greece, the resistance of the soil in connection with the moisture and the category of the native stone, the pressure that tires of tractors exert in the soil, are estimated. It also estimated the percentage of the trees in the remaining stand which suffer damages from the movement of various means. The above means are used for the skidding of wood of different lengths. According to the results of the research some measures are suggested so as to decrease the damages, which are caused in the soil and in the remaining stand.
