OBJECTIVE: To investigate the biomechanical characteristics of Schatzker type Ⅱ tibial plateau fracture fixed by different bone grafting methods and internal fixations. METHODS: Twenty-four embalmed specimens of adult knee joint were selected to make Schatzker type Ⅱ tibial plateau fracture models, which were randomly divided into 8 groups (groups A1-D1 and groups A2-D2, n=3). After all the fracture models were restored, non-structural iliac crest bone grafts were implanted in group A1-D1, and structural iliac crest bone grafts in groups A2-D2. Following bone grafting, group A was fixed with a lateral golf locking plate, group B was fixed with lateral golf locking plate combined compression bolt, group C was fixed with lateral tibial "L"-shaped locking plate, and group D was fixed with lateral tibial "L"-shaped locking plate combined compression bolt. Compression and cyclic loading tests were performed on a biomechanical testing machine. A distal femur specimen or a 4-cm-diameter homemade bone cement ball were used as a pressure application mould for each group of models. The specimens were loaded with local compression at a rate of 10 N/s and the mechanical loads were recorded when the vertical displacement of the split bone block reached 2 mm. Then, compressive and cyclic loading tests were conducted on the fixed models of each group. The specimens were compression loaded to 100, 400, 700, and 1 000 N at a speed of 10 N/s to record the vertical displacement of the split bone block. The specimens were also subjected to cyclic loading at 5 Hz and 10 N/s within the ranges 100-300, 100-500, 100-700, and 100-1 000 N to record the vertical displacement of the split bone block at the end of the entire cyclic loading test. The specimens were subjected to cyclic loading tests and the vertical displacement of the split bone block was recorded at the end of the test. RESULTS: When the vertical displacement of the collapsed bone block reached 2 mm, the mechanical load of groups A2-D2 was significantly greater than that of groups A1-D1 ( P<0.05). The mechanical load of groups B and D was significantly greater than that of group A under the two bone grafting methods ( P<0.05); the local mechanical load of group D was significantly greater than that of groups B and C under the structural iliac crest bone grafts ( P<0.05). There was no significant difference ( P>0.05) in the vertical displacement of the split bone blocks between the two bone graft methods when the compressive load was 100, 400, 700 N and the cyclic load was 100-300, 100-500, 100-700 N in groups A-D. However, the vertical displacement of bone block in groups A1-D1 was significantly greater than that in groups A2-D2 ( P<0.05) when the compressive loading was 1 000 N and the cyclic load was 100-1 000 N. The vertical displacement of bone block in group B was significantly smaller than that in group A, and that in group D was significantly smaller than that in group C under the same way of bone graft ( P<0.05). CONCLUSION Compared with non-structural iliac crest bone grafts implantation, structural iliac crest bone grafts is more effective in preventing secondary collapse of Schatzker type Ⅱ tibial plateau fracture, and locking plate combined with compression bolt fixation can provide better articular surface support and resistance to axial compression, and the lateral tibial "L"-shaped locking plate can better highlight its advantages of "raft" fixation and show better mechanical stability.
Humans ; Bone Transplantation/methods* ; Tibial Fractures/physiopathology* ; Fracture Fixation, Internal/instrumentation* ; Biomechanical Phenomena ; Bone Plates ; Ilium/transplantation* ; Adult ; Tibia/surgery* ; Bone Cements ; Knee Joint/surgery* ; Male ; Tibial Plateau Fractures

Mechanical ventilation is an advanced life support treatment for patients with acute respiratory failure. While stabilizing respiratory function, it also acts as an injury factor to exacerbate or lead to lung injury, that is, ventilation-induced lung injury (VILI). There may be a more subtle form of damage to VILI known as "biotrauma". However, the mechanism of biotrauma in VILI is still unclear. This article intends to review the mechanism of biotrauma of VILI from the aspects of inflammatory response, oxidative stress and complement activation, in order to provide a new strategy for clinical prevention and treatment of biotrauma caused by VILI.

Objective To investigate the effects of sex hormone-binding globulin (SHBG)gene in the apoptosis of human trophoblastic cells.Methods The siRNA specific-targeting SHBG gene was transfected into human trophoblastic cells and they were divided into six groups:trophoblasts without transfection in normal control groups(group Ⅰ);transfect liposome in blank control groups(group Ⅱ);transfect nonspecific siRNA in negative control groups(group Ⅲ);transfect SHBG siRNA-Ⅰ,SHBG siRNA-Ⅱ,SHBG siRNA-Ⅲ respectively in trans-fection group(group Ⅳ,Ⅴ,Ⅵ).Hoechst 33258 dying method was used to detect cell apoptosis.SHBG and Caspase-3 mRNA profiling and the level of SHBG and caspase-3 protein were detected by real-time PCR and Western blot.Results There was no statistical significant difference in the gene expression and protein level of SHBG and caspase-3 in group Ⅰ,Ⅱ and Ⅲ (P >0.05).In Ⅳ,Ⅴ and Ⅵ group,there was no statistical significant difference in the expression level of SHBG and caspase 3 (P >0.05).Compared with group Ⅰ,Ⅱ and Ⅲ,the a-mount of SHBG gene expression decreased obviously,the caspase-3 mRNA and protein level increased obviously and the trophoblast cell ap-optosis increased markedly (P <0.05).Conclusion Through siRNA interference technology can reduce SHBG gene expression in human trophoblastic cells,and it can lead to excessive apoptosis of human trophoblasts cells.

Objective To explore the relationship between sex hormone-binding globulin (SHBG) of gestational diabetes mellitus ( GDM ) pregnant women with well-controlled glucose and pregnancy outcomes. Methods Two hundred and fifty-one GDM pregnant women of 24 - 28 weeks in Shengjing Hospital of China Medical University were recruited from Mar. 2005 to Mar. 2010. Two hundred and sixteen cases of GDM with well-controlled glucose were defined as glycemic satisfied group, and they were treated by diet therapy ( 169 cases) or insulin therapy (47 cases) . Thirty-five cases with unsatisfied glucose were defined as glycemic unsatisfied group. One hundred and ninety-two healthy pregnant women of 24 - 28 weeks were defined as healthy control group. Serum SHBG and homeostasis model analysis of insulin resistance ( HOMA-IR) at 24 - 28 weeks and above 36 weeks were measured. GDM was diagnosed bytwo-step method according to the National Diabetes Data Group ( NDDG) criteria. The pregnancy outcomes and complications of the three groups were recorded. Results ( 1 ) Comparison of pregnancy outcomes and complications: glycemic satisfied group was less likely to develop hypertensive disorders in pregnancy ( 10. 6% ) , premature birth(8. 3% ) ,large for gestational age ( LGA) (8. 8% ) , neonatal asphyxia(3. 7% ) and neonatal hypoglycemia ( 2. 3% ) compared to glycemic unsatisfied group ( 42. 9% , 34. 3% , 31. 4% , 22. 9% and 11. 4% ,respectively). And the difference was statistically significant (P ＜0. 05 or P ＜0. 01). There was no significant difference for incidence of polyhydramnios, pueperal infection, postpartum hemorrhage, neonatal hyperbilirubinemia between the two groups ( P＞ 0. 05 ) . When compared to healthy control group(7. 3% ,2. 1% ,4. 2% ,2. 1% and 1. 6% ) ,no significant difference was found for incidence of premature birth( 8. 3% ) , pueperal infection ( 3. 2% ) , postpartum hemorrhage (5. 1% ) , neonatal asphyxia (3. 7% )and neonatal hypoglycemia(2. 3% ,P ＞0. 05). (2) Comparison of results of 24 - 28 weeks and above 36 weeks: serum SHBG of glycemic satisfied group [( 384 ± 88 ) , (457 ± 48 ) nmol/L]was significantly higher than that of glycemic unsatisfied group[(313 ±45) ,(401 ±73) nmol/L];HOMA-IR of glycemic satisfied group (5. 3 ±1.1,5.5 ±1.1) was significantly lower than that of glycemic unsatisfied group (7. 0 ± 1. 3 ,7. 6 ± 1. 7 ; P ＜ 0. 01). Serum SHBG of glycemic satisfied group was significantly lower than that of healthy control group [( 492 ± 95 ) , (565 ± 40 ) nmol/L]; and HOMA-IR of glycemic satisfied group(5. 3 ± 1. 1,5. 5 ± 1. 1) was significantly higher than that of healthy control group (3. 6 ±0. 6,3. 9 ± 0. 5 ;P ＜ 0. 01 ) . FPG of glycemic satisfied group [( 5. 84 ± 0. 28 ) , ( 5. 16 ± 0. 13 ) mmol/L]was significantly lower than that of glycemic unsatisfied group [(6. 13 ± 0. 16 ) , ( 5. 68 ± 1. 14) mmol/L; P ＜ 0. 01]. FINS of glycemic satisfied group [( 20. 4 ± 2. 1 ) , ( 24. 1 ± 4. 2 ) mmol/L]was significantly lower than that of glycemic unsatisfied group [(24. 7 ± 4. 5 ) , ( 29. 9 ± 2. 7 ) mmol/L; P ＜ 0. 01]. ( 3 ) Correlation analysis. Between 24 - 28 weeks, SHBG was negatively correlated with HOMA-IR in the three groups ( r = -0. 952, P ＜0. 01) ; and SHBG was negatively correlated with HOMA-IR in glycemic satisfied group ( r = -0. 903, P ＜0. 01). Conclusions Well-controlled glucose can not completely improve maternal and fetal outcomes of GDM pregnant women. High insulin resistance and low serum SHBG can influence pregnancy outcomes.