[Comparative Evaluation of the Value of Quantitative Parameters of Dual-energy CT and MRI for KRAS Mutation in Rectal Cancer].

Objective To evaluate and compare the value of quantitative parameters of preoperative dual-energy CT and MRI on KRAS mutation in rectal cancer,and to explore the correlations between postoperative pathological indicators and KRAS mutation. Methods This study retrospectively analyzed 50 patients with rectal cancer confirmed by surgery and pathology and receiving KRAS genetic testing in Lanzhou University Second Hospital from August 2017 to April 2021.According to the results of genetic testing,the patients were assigned into a wild-type group (29 patients) and a mutant type group (21 patients).The preoperative baseline data included sex,age,and serum tumor markers,and the postoperative pathological data included pathological stage,lymphovascular invasion,perineural invasion,and lymph node metastasis.The quantitative parameters of three-phase energy spectral CT included iodine (water) concentration,water (iodine) concentration,effective atomic number,and normalized iodine concentration.The quantitative parameters of apparent diffusion coefficient (ADC) included minimum ADC,average ADC,and relative ADC.In addition,the width of the superior rectal vein was obtained from the CT images of the venous phase,and the tumor segmentation,the maximum axial length of tumor,and the maximum longitudinal length of tumor were obtained from the MRI images.The qualitative and quantitative data were compared by χ2 test,t-test,and Mann-Whitney U test.The diagnostic efficacy of the two detection methods for KRAS mutations in rectal cancer was compared,and the receiver operating characteristic curve was employed to evaluate the diagnostic efficacy. Results The KRAS mutation rate was higher in the carbohydrate antigen 199 abnormal group than the normal group (P=0.036) and higher in the positive group of lymphovascular invasion (P=0.034).The KRAS mutant type group had higher normalized iodine concentration in the venous phase (P=0.016) and lower average ADC and relative ADC (P=0.008, P=0.002,respectively) than the wild-type group.Among them,relative ADC had the highest diagnostic efficiency (AUC=0.755). Conclusion The quantitative parameters of dual-energy CT and ADC have similar diagnostic efficiency for KRAS mutation in rectal cancer,and relative ADC is superior to other parameters.

Sulfur dioxide reduces lipopolysaccharide-induced acute lung injury in rats.

INTRODUCTION: Recent studies suggested that sulfur dioxide (SO2) can be produced endogenously by pulmonary vessels and attenuate acute lung injury (ALI) with vasorelaxant effects. This study was conducted to determine whether SO2 can inhibit lung inflammation and relax pulmonary arteries via inhibition of the mitogen-activated protein kinase (MAPK) pathway. MATERIAL AND METHODS: Forty-eight adult male Sprague Dawley rats (250~300 g) were randomly divided into six treatment groups: control (n = 8), control + SO2 (n = 8), control + L-aspartic acid-ß-hydroxamate (HDX) (n = 8), LPS (n = 8), LPS + SO2 (n = 8) and LPS + HDX (n = 8). RESULTS: Six hours after LPS treatment, rats exhibited elevated pulmonary artery hypertension (PAH), marked pulmonary structure injury with elevated pulmonary myeloperoxidase (MPO) activity and increased expression of intercellular adhesion molecule 1 (ICAM-1) and CD11b, along with decreased pulmonary SO2 production and reduced pulmonary aspartate aminotransferase (AAT) activity. Pretreatment with SO2 saline solution significantly reduced, while HDX (AAT inhibitor) aggravated, the pathogenesis of LPS-induced ALI. Moreover, SO2 saline solution significantly down-regulated expression of Raf-1, MEK-1 and phosphorylated ERK (p-ERK). It also prevented pulmonary hypertension in association with an up-regulated SO2/AAT pathway. However, HDX advanced pulmonary hypertension and inflammatory responses in the lung were associated with a down-regulated SO2/AAT pathway. CONCLUSIONS: Our results suggest that SO2 markedly relieved inflammatory responses, in association with Raf-1, MEK-1 and p-ERK during ALI induced by LPS. The down-regulation of the SO2/AAT pathway may be involved in the mechanism(s) of LPS-induced lung injury.

Locking plate versus external fixation for type C distal radius fractures: A meta-analysis of randomized controlled trials.

PURPOSE: Distal radial fracture is one of the most common fractures. Up to now, locking plates (LP) and external fixation (EF) are two conventional surgical approaches to type C radius fracture. Which method is superior has not yet reached a consensus. We try to assess the clinical effectiveness of the two interventions by this meta-analysis. METHODS: We used network to search the PubMed, Embase, and Cochrane Medical Library of randomized controlled clinical trials about the type C distal radius fractures performed according to the search strategy mentioned in Cochrane Handbook 5.1.0 from Jan. 2005 to Jan. 2016. Patients in the experimental group were used LP, in the control group were included EF and other surgical approaches. Publication language was restricted to English. Studies that patient population and surgical indication did not define had been excluded. Studies must report at least one of the outcomes as follow: radial inclination, palmar tilt, ulnar variance, range of wrist flexion and extension, and range of wrist supination and pronation. The trials in which participants included children were excluded. We used Jadad study scores to appraise the study. RESULTS: Seven studies included 162 patients (LP group) and 190 patients (EF group). We compared the radial inclination, palmar tilt, ulnar variance, range of wrist flexion and extension, and range of wrist supination and pronation. The radial inclination were revealed a difference favoring LP over EF [WMD = 1.84, 95% CI (0.17, 3.50), p = 0.03] and the palmar tilt and ulnar variance was no significant difference between the two groups [(WMD = 3.61, 95% CI (0.00, 7.23), p = 0.05; WMD = 0.05, 95% CI (-0.99, 1.09), p = 0.93]. The functional activities of range of flexion and extension and range of supination and pronation between the two groups was no difference [WMD = 10.04, 95% CI (-6.88, 26.96), p = 0.24; WMD = 12.53, 95% CI (-9.99, 35.06), p = 0.28]. CONCLUSION: Locking plate and external fixation is feasible to heal radius type C fracture. We found the small difference between the two groups on imaging examination. The locking plate has the advantage on maintaining reduction, however no significant difference regarding outcomes has been found between the two groups.

Low dose of lipopolysaccharide pretreatment can alleviate the in?ammatory response in wound infection mouse model.

PURPOSE: To assess the effects of lipopolysaccharide (LPS) pretreatment on wound infection mouse model and evaluate the biological safety of the optimal pretreatment dose in vivo. METHODS: Mice were pretreated with LPS of different doses at 48 and 24 h before femoral medial lon- gitudinal incision was made and infected with different bacteria. RESULTS: It is showed that 0.5 mg/kg/time of LPS pretreatment can significantly alleviate the inflammation in mouse model infected with methicillin-resistances Staphylococcus aureus, methicillin-sensitive S. aureus, Pseudomonas aeruginosa,or Escherichia coli compared with doses of 0.25 mg/kg/time, 1 mg/ kg/time, and 1.5 mg/kg/time. CONCLUSIONS: LPS pretreatment can alleviate the inflammation in mouse model and the optimal dose is 0.5 mg/kg/time, and meanwhile it does not damage organs' function.

Gallic acid can play a chondroprotective role against AGE-induced osteoarthritis progression.

BACKGROUND: Advanced glycation end products (AGEs) are a group of stable covalent compounds generated by proteins, lipids, other macromolecules and sugar through a series of non-enzymatic reactions. As reported, AGEs can cause widespread pathophysiological responses through activation of AGE receptors (RAGEs) on the cell surface, and play an important role in the pathogenesis of osteoarthritis (OA). We hypothesized that the antioxidant and anti-glycan agent gallic acid (GA) can work against the effects of AGEs and can be used as a potential drug for the cure of OA. METHODS: The present study first explored the negative functions of AGEs via AGE-treated chondrocytes isolated form rabbits. Then, we observed the protective role of GA in AGE-treated chondrocytes by measuring the reactive oxygen species (ROS), superoxide dismutase (SOD), collagen II, aggrecan, nitric oxide synthase (iNOs) and cyclooxygenase-2 (COX-2) in vitro. Finally, the changes in a cartilage lesion in a rabbit model of knee osteoarthritis was observed. RESULTS: Exposure of chondrocytes to AGEs resulted in a reduction of ROS, SOD, collagen II and aggrecan, and an increase in iNOs and COX-2, which means exposure promoted OA lesions in a clinical setting. When AGE-treated chondrocytes were pretreated with GA, there were no significant changes in these key components compared to the normal chondrocytes. In vivo study showed cartilage degradation was reduced by GA as compared to the vehicle group. CONCLUSION: The results of this study confirmed the chondroprotective role of GA and provide a potential drug for the relief of OA.

A new approach for the treatment of proximal humeral fractures using the TRIGEN proximal humeral nail.

The optimal surgical treatment for displaced proximal humeral fractures continues to be controversial. One of the new treatment options is the minimally invasive intramedullary nail. The purpose of this study was to evaluate the functional outcome of using the TRIGEN proximal humeral nail (PHN) for the treatment of displaced proximal humeral fractures in elderly patients. From January 2004 to December 2008, 64 elderly patients (age > 60 years old) with displaced proximal humeral fractures were treated using TRIGEN PHN. A complete 12-month postoperative follow-up was available for 54 patients. The study cohort included two-part (29 shoulders), three-part (22 shoulders), and four-part (3 shoulders) Neer classification fracture types. The Constant-Murley score was used to assess functional outcome. Radiological outcomes were evaluated, and all complications were recorded. All fractures were united. The Constant-Murley score data indicated that the patients experienced improvement from 6 to 12 months postoperatively. The mean absolute Constant-Murley score on the injured side increased from 71.2 ± 11.2 points at 6 months to 82.4 ± 16.4 points at 12 months (P = 0.01). The mean neck-shaft angle 1 year after surgery was 125° ± 8.1° (95°-140°). Secondary complications were minimal and observed in only 6 of 54 patients. In conclusion, the TRIGEN intramedullary humeral nail is effective for the treatment of proximal humeral fractures.

Role of sulfur dioxide in acute lung injury following limb ischemia/reperfusion in rats.

Sulfur dioxide (SO2) is naturally synthesized by glutamate-oxaloacetate transaminase (GOT) from L-cysteine in mammalian cells. We aim to investigate the role of SO2 in inflammation in acute lung injury (ALI) following limb ischemia/reperfusion (I/R). Male Wistar rats were subjected to limb I/R and were injected with saline, GOT inhibitor hydroxamate (HDX, 0.47 mmol/kg), or the SO2 donor Na2 SO3 /NaHSO3 (0.54 mmol/kg/0.18 mmol/kg). Compared with the sham operation, the plasma SO2 levels were significantly decreased by limb I/R treatment. In addition, SO2 concentration and GOT activity in the lung tissue were also reduced in ALI. The occurrence of ALI following limb I/R can be prevented by Na2 SO3 /NaHSO3 treatment, whereas it can be significantly aggravated by HDX. The plasma IL-1ß, IL-6, and IL-10 levels were consistent with myeloperoxidase activity and inflammation in lung tissue. In conclusion, our data suggest that downregulation of endogenous SO2 production might be involved in pathogenesis of ALI following limb I/R in rats.

Three-dimensional fracture mapping and analysis of coronal fractures in AO/OTA types 33-B3 and C3.

BACKGROUND: Although the relatively high incidence of coronal fractures in the supracondylar-intercondylar fractures is well established, little is currently known about the morphology of those fractures. Herein, we characterized the coronal fractures in AO/OTA type 33-C3 and assessed their differences with Busch-Hoffa fractures (33-B3). METHODS: We retrospectively collected 61 cases of AO/OTA type 33-B or C fractures with coronal plane fragments and generated three-dimensional fracture maps of those with coronal fractures based on CT imaging and measured angle α (the angle between the coronal fracture and the posterior condyle axis in the axis plane) and angle ß (the angle between the coronal fracture and the posterior femoral cortex in the sagittal plane). RESULTS: Thirty-three cases (32%) of AO/OTA type 33-C fractures contained coronal fragments. Most of them were type 33-C3 fractures. Angles α and ß for type 33-C3 were significantly smaller than for type B3 at the lateral condyle, while the angles at the medial condyle were not significantly different. The fracture maps showed that the coronal fractures and the articular comminution area were more anterior in type 33-C3. CONCLUSIONS: The incidence of coronal fractures was 32% and 67% in AO/OTA types 33-C and 33-C3, respectively. Our findings suggest that coronal fractures differed between both types, emphasizing the potential need for different treatment approaches.

[Choice of internal fixation methods for posterior malleolus fracture in both biomechanics and clinical application].

OBJECTIVE: To study the biomechanical effects and the clinical outcome of different internal fixation methods in treating posterior malleolus fractures. METHODS: (1) Biomechaniccal study of 18 pairs of posterior malleolus fracture models was conducted, in which all the cases were divided into 3 groups as I, II and III (n=12), according to different fracture degrees that included specimens with 1/4, 1/3 and 1/2 of articular facets fractured respectively; Each group was further divided into 2 subgroups as group A and group B. Group A was fixed with 2 steel half-thread tensile screws whose diameter was 4.0 mm; and group B was fixed with "T-shaped" steel distal-radius plates and 4 screws. The uploading experiment was carried out by settling the specimen on an experiment machine at its neutral position, and the data were collected and managed. (2) Clinical Applications: 31 cases with closed trimalleolar fractures were treated from 2009.1-2010.12 in our hospital, in which 14 with posterior malleolus fractures ≤ 2 5% of the capital diameter of the tibial plafond were fixed with screws, and 17 with posterior malleolus fractures >25% of the capital diameter of the tibial plafond were fixed with steel plates. Prospective cohort study of these cases were carried out. The outcome was assessed using a Leeds Scoring System. RESULTS: The mechanical fixation strengths of the plates for 1/4, 1/3 and 1/2 facets of posterior malleolus fractures were all higher than those of the screw groups [(4.10 ± 0.13) kN vs. (4.6 0 ± 0.27)kN, (3.20 ± 0.12)kN vs. (4.12 ± 0.14)kN and (1.98 ± 0.18)kN vs. (3.72 ± 0.18)kN, respectively, P<0.05]. For the clinical study ,the mean follow-up period was 12 months (6-18 months), all the cases acquired bone union, and the mean time for healing was 10 weeks ( 8-12 weeks). In the evaluation of therapeutic effects, we found that 28 cases were excellent and 3 good, which was 100% satisfying. CONCLUSION: If only 1/4 of the posterior articular facet is involved, 2 screws are enough to supply the stability; but for the fractures involve more than 1/4 facet, the plate fixation supplies more stable fixation and is superior to simply screws.

Development of a tibial experimental non-union model in rats.

BACKGROUND: Many non-union animal models have been developed to explore the problems surrounding fracture healing. However, the existing models are not perfect and cannot satisfy all non-union studies. This study aimed to make a non-union model of the tibia in rats by cauterization of the posterior of 2 mm on both sides of the fracture end after open osteotomy of the tibia and fixing the fractured tibia with a Kirschner wire 0.8 mm in diameter. METHODS: For this study, 96 female adult Sprague-Dawley (SD) rats were used. The rats underwent surgery to produce a tibial open fracture and were fixed with a 0.8-mm diameter Kirschner wire. In 48 of the rats, the periosteum proximal and distal to the fracture end was cauterized. RESULTS: At 2, 4, 6, and 8 weeks after surgery, radiological and histological analysis showed typical physiological healing in the control group, and the healing rate was 100% at 6 weeks. But the non-union group was characterized by resorption of the fracture ends with few callus formations and no bridging callus formation, and the healing rate was 0% at 8 weeks. CONCLUSIONS: This method represents a reproducible model to create atrophic non-unions. This model provides a new option for studying the basic healing mechanisms and evaluating new therapies for bone regeneration and treatment of non-unions.

Analysis of the Sagittal Motion Posture of the Acromioclavicular Joint Using Image Registration and Axial Angle Representation.

OBJECTIVE: This study aimed to directly and accurately measure the range of motion of the acromioclavicular joint through 3D reconstruction and image registration. METHODS: Thirteen healthy volunteers participated in the study. Computerized tomography (CT) was used to measure the acromioclavicular joint in four different motion poses. The images were integrated using reconstruction and registration technology, and the rotation angle range of the acromioclavicular joint was measured using 3D reconstruction. The measurements were expressed by axial angle representation. The dominant and the non-dominant sides were compared, and the difference in the axial angle of the acromioclavicular joint was compared in different postures. RESULTS: The difference between the dominant and non-dominant sides in acromioclavicular motion was not significant. In the sagittal motion of the upper limb, the rotation angle of the acromioclavicular joint was greatest in a resting horizontal position, with an average of 26.1°. In this position, 34.6% of flexion and extension movements of the upper limb were completed by the acromioclavicular joint, which was the highest level of engagement. The rotation angle was lowest in the resting posteroinferior position, with an average of 8.2°. In this position, 24.9% of the flexion and extension movements of the upper limb were completed by the acromioclavicular joint. CONCLUSION: Combining 3D reconstruction and image registration is a direct and accurate method of measuring the motion of the acromioclavicular joint. The rotational motions of the acromioclavicular joint are bilaterally symmetrical and can be used as a reference for comparative study. The maximum range of motion of the acromioclavicular joint during rotation was found in the resting horizontal position. The clinical examination and post-treatment evaluation of the acromioclavicular joint's rotation function can therefore be targeted in this range.

Application of Image Registration to Analyze the Clavicular Rotation of Normal Upper Limb Motion in the Sagittal Plane.

OBJECTIVE: To use image registration techniques to study the clavicular rotation of the shoulders in the sagittal plane. METHODS: From 28 April 2019 to 20 May 2019, 13 healthy adults (7 males and 6 females) with no history of shoulder trauma surgery or chronic pain were recruited. Patients' ages ranged from 22 to 42 years, with a mean age of 26.5 years. Three-dimensional composite images of the sternum-clavicle-humerus were taken using CT images of upper limb movement in the sagittal plane in the 13 healthy adults. Four different postures were registered: (i) anatomical supine position; (ii) elbow joints lifted anteriorly in the supine position; (iii) posterosuperior hyperextension of the elbow joints in the prone position; and (iv) posteroinferior hyperextension of the elbow joints in the prone position. Image data from the humerus and clavicle in three of the postures were processed to calculate Euler angles for movements in the sagittal plane. SPSS 19 was used to perform statistical analyses. RESULTS: There was no significant difference in the angles of change in the clavicle and humerus between the dominant and non-dominant sides under different movement patterns. For upper limb movements in the sagittal plane, the clavicle displayed different Euler angles in different postures. The rotation angle from the anatomical to the horizontal position was the smallest angle, with an average value of 7.1°, whereas the rotation angle from horizontal to posterosuperior hyperextension was the largest, with an average value of 37.2°. When the upper limb moved from anterior protraction to a posterosuperior extension, the intrinsic rotation angle of the clavicle reached its maximum, with an average value of 27.9°; when moved from the anatomical to the horizontal position, 9.1% of the sagittal rotation was executed by the clavicle. During rotation from the horizontal position to posterosuperior hyperextension and from the anatomical to posterior extension, the clavicle showed relatively higher weights at 29.5% and 37.0%, respectively. CONCLUSION: Our results showed that dominance was not a consideration when studying clavicular rotation. Image registration is an effective method that can be used to study upper limb scapular movements. Through comparing and analyzing the data, two postures had relatively large changes in the rotation angle. This can help improve indicators of clavicular rotational function during physical examinations and postoperative functional evaluations.

[Role of polymorphonuclear neutrophil in exogenous hydrogen sulfide attenuating endotoxin-induced acute lung injury].

The animal model of acute lung injury (ALI) caused by intravenous injection of lipopolysaccharides (LPS) and cultured human peripheral blood polymorphonuclear neutrophil (PMN) were used to study the effects of sodium hydrosulfide (NaHS), hydrogen sulfide (H2S) donor, on LPS-induced PMN accumulation, microvascular permeability and PMN apoptosis. Control group, NaHS group, LPS group and LPS + NaHS group were established both in in vivo and in vitro studies. Microvascular permeability, PMN accumulation in lung and apoptosis of PMN were detected. The results showed that: (1) In in vivo study, PMN accumulation in lung, the protein content in bronchoalveolar lavage fluid (BALF) and the Evans blue dye in lung tissue of LPS group were markedly higher than those of both sham operation group and LPS + NaHS group (P<0.05, P<0.01); (2) In in vitro study, the apoptotic rates of PMN in LPS group and NaHS group were significantly higher than that in control group (P<0.01), while compared with LPS group, LPS + NaHS group showed significantly higher apoptotic rate (P<0.01). These results suggest that NaHS attenuates LPS-induced microvascular permeability and alleviates ALI. PMN apoptosis induced by NaHS is possibly one of the potential mechanisms underlying the decrease of PMN accumulation in lung tissue.

[Ameliorative effects of exogenous sulfur dioxide on lipopolysaccharide-induced acute lung injury in rats].

To investigate the influence of sulfur dioxide (SO2) on lipopolysaccharide (LPS)-induced acute lung injury (ALI), we examined the influence of exogenous SO2 on pulmonary tissue inflammatory response. A rat model of ALI induced by intravenous (IV) injection of LPS was developed. Male Sprague-Dawley (SD) rats were divided into four groups randomly: control group, LPS group, LPS plus SO2 group (IV injection of 0.5 mL Na2SO3/NaHSO3 10 min before LPS administration) and SO2 group (only given Na2SO3/NaHSO3). Animals were sacrificed 6 h after agent administration. Lung weight/body weight ratio (LW/BW) was measured and calculated. Morphological changes of lung tissues were observed. The number of polymorphonuclear neutrophil (PMN) in the bronchoalveolar lavage fluid (BALF), intercellular adhesion factor-1 (ICAM-1) expression in the lung tissue and IL-1, IL-6 and IL-10 levels in the serum were tested. The results showed that, compared to control rats, the LPS-treated rats had severe injuries of lung tissues and an increased LW/BW, increased index of quantitative assessment (IQA) score, increased PMN number in the BALF, increased ICAM-1 expression in the lung tissue and increased IL-1, IL-6 and IL-10 levels in the serum 6 h after LPS injection. Administration of the SO2 donor, Na2SO/3NaHSO3, into LPS-treated rats reduced the LW/BW, PMN number and ICAM-1 expression, and alleviated the degree of ALI (measured by the IQA score). In addition, Na2SO3/NaHSO3 decreased IL-1 and IL-6 levels, but increased IL-10 level in the serum. There were no significant differences in the above indexes between SO2-treated rats and control rats. These results suggest that exogenous SO2 could inhibit the pulmonary tissue inflammatory response in rats with LPS-induced ALI.

Protection of carbon monoxide-releasing molecule against lung injury induced by limb ischemia-reperfusion.

OBJECTIVE: To observe the role and mechanism of CO-releasing molecule (CORM)-2 in lung injury induced by ischemia-reperfusion (IR) of hind limbs in rats. METHODS: A rat model of lung injury induced by IR of hind limbs was established. A total of 40 Sprague Dawley (SD) rats were randomly divided into 5 groups (n equal to 8): sham, sham + CORM-2, IR, IR + CORM-2 and IR + dimethyl sulfoxide (DMSO). Rats in the IR group received hind limb ischemia for 2 hours and reperfusion for 2 hours, rats in the sham group underwent sham surgery without infrarenal aorta occlusion, rats in the IR+CORM-2 group and in the sham + CORM-2 group were given CORM-2 (10 micromol/kg intravenous bolus) 5 minutes before reperfusion or at the corresponding time points, while rats in the IR + DMSO group was treated with the same dose of vehicle (DMSO) at the same time. The lung tissue structure, polymorphonuclear neutrophil (PMN) count, wet-to-dry weight ratio (W/D), malondialdehyde (MDA) content, myeloperoxidase (MPO) activity, intercellular adhesion molecule-1 (ICAM-1) expression,IkBa degradation and nuclear factor (NF)-kB activity in the lungs were assessed. RESULTS: As compared with the sham group, lung PMNs number, W/D, MDA content, MPO activity, ICAM-1 expression and NF-kB activity significantly increased in the IR group, but the level of IkBa decresed (P less than 0.01). Compared with the IR group, lung PMNs number, W/D, MDA content, MPO activity and ICAM-1 expression significantly decreased in the IR+COMR-2 group (P less than 0.01), while the level of IkBa increased. CONCLUSIONS: These data demonstrate that CORM-2 attenuates limb IR-induced lung injury through inhibiting ICAM-1 protein expression, NF-kB pathway and the leukocytes sequestration in the lungs following limb IR in rats, suggesting that CORM-2 may be used as a therapeutic agent against lung injury induced by limb IR.

Functional Outcome of Pronation-External Rotation-Weber C Ankle Fractures with Supracollicular Medial Malleolar Fracture Treated with or without Syndesmotic Screws: A Retrospective Comparative Cohort Study.

BACKGROUND: In treatment of ankle fracture, intraoperative stress tests are used to assess the syndesmotic injury and instability. However, the optimized timing of the strees test should be applied whether in pre- or post-bony fixation during operation is seldom be reported in previous studies. The different strategies on stress test timing would exhibit opposite results within a type of pronation-external rotation (PER) fractures with supracollicular medial malleolar (SMM) fractures. This study was designed to assess the 3-year functional outcomes of the special PER fractures with or without a syndesmotic transfixation based on the results of two different intraoperative stress test strategies. METHODS: This retrospective cohort study included 61 PER injury-Weber C ankle fractures combined with SMM fractures who were treated in Beijing Jishuitan Hospital between 2013 and 2014 and followed up for 3 years. Stress test was performed twice intraoperatively. A positive intraoperative stress test before bony fixation and a negative intraoperative stress test after bony fixation were found in these included patients. Twenty-nine patients (Group 1) were treated without a supplemental syndesmotic screw fixation, according to the negative intraoperative stress test after bony fixation, while 32 patients (Group 2) were treated with an additional syndesmotic screw fixation based on the positive intraoperative stress test before bony fixation. The American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale and Visual Analog Scale (VAS) for pain scores were the main measurements of outcome. The statistical index of demographic data, fracture morphologic data, time interval of follow-up, AOFAS and VAS were recorded and assessed by SPSS 21.0 software through Fisher exact tests and one-way analysis of variance. The associations between the main outcomes and influential factors were evaluated by linear regression models. RESULTS: We observed no difference in the distribution of age, sex, presence of associated posterior malleolus (PM), fracture dislocation, and fixation of associated PM between two treatment groups. With the numbers available, no statistically significant association could be detected with regard to the AOFAS (Group 1 vs. Group 2, 96.72 ± 6.20 vs. 94.63 ± 8.26, F = 1.24, P = 0.27) and VAS (Group 1 vs. Group 2, 1.47 ± 2.14 vs. 0.72 ± 1.49, F = 2.44, P = 0.12) in association with two strategies. CONCLUSIONS: The present study indicates no difference to the use of the syndesmotic screw in terms of the functional outcome between syndesmosis transfixation and no-fixation patients among PER-Weber C ankle fracture patients with SMM fracture after 3-year follow-up. More attention should be paid to pre- and post-bony-fixation intraoperative stress tests and the morphology of medial malleoli fractures in ankle fractures.

An Experimental Study on Repeated Brief Ischemia in Promoting Sciatic Nerve Repair and Regeneration in Rats.

BACKGROUND: Research has shown that ischemic preconditioning reduced the severity of ischemia-reperfusion injury in brain in rats, we have a hypothesis that repeated brief ischemia has positive effects on peripheral nerve damage. This study was conducted to investigate the potential protective effects of repeated brief ischemia on peripheral nerve regeneration using a rat model of experimental sciatic nerve transection injury. METHODS: Treatment groups (groups A-D) received repeated, brief ischemia every 1 day/2 days/3 days/7 days. After surgery for 4, 8, 12 weeks, we evaluated sciatic functional index test, gastrocnemius muscle wet mass, axon and nerve fiber diameter, density, G-ratio, immunohistochemistry of S-100, vascular endothelial growth factor (VEGF), and the ultrastructure of the nerves. RESULTS: Sciatic functional index test and muscle wet mass were improved on the repeated brief ischemia groups. Ischemia treatment resulted in a significant increase in axon and nerve fiber density as well as S-100 and VEGF-positive cell, which indicated that repeated brief ischemia promotes Schwann cell proliferation and reconstruction. CONCLUSIONS: This study exhibits the positive effects of repeated brief ischemia in sciatic nerve transection injury, possibly in part because it can improve VEGF and the physiologic state of Schwann cells in the ischemic environment and then accelerate the ability of neurite outgrow.

Neuroprotective effect of ischemic postconditioning on sciatic nerve transection.

Ischemic preconditioning or postconditioning has been shown to have neuroprotective effect on cerebral ischemia, but it has not been studied in peripheral nerve injury. In this study, a rat model of sciatic nerve transection was established, and subjected to three cycles of ischemia for 10 minutes + reperfusion for 10 minutes, once a day. After ischemic postconditioning, serum insulin-like growth factor 1 expression increased; sciatic nerve Schwann cell myelination increased; sensory function and motor function were restored. These findings indicate that ischemic postconditioning can effectively protect injured sciatic nerve. The protective effect is possibly associated with upregulation of insulin-like growth factor 1.

[Effects of calcitonin on osteoblast cell proliferation and OPG/RANKL expression: experiment with mouse osteoblasts].

OBJECTIVE: To investigate the effects of calcitonin on the proliferation of osteoblasts and the OPG/RANKL expression therein. METHODS: Osteoblasts were separated by enzyme digestion methods from the cranial bones of 30 newborn mice, cultured, and inoculated in 96-well plate. Calcitonin of the concentrations of 10, 40, and 80 IU/L was administrated into the culture medium for 24, 48, and 72 hours. The proliferation of osteoblasts was detected by MTT method. Flow cytometry was used to analyze the cell cycle. The mRNA expression of osteoprotegerin (OPG) and RANKL and protein expression of OPG were examined by RT-PCR and ELISA respectively. RESULTS: The proliferation rates of the osteoblasts exposed to the calcitonin of the concentrations of 40 and 80 IU/L for 24. 48, and 72 hours cell were all significantly higher than those of the blank control group (P < 0.05, P < 0.01). The index of osteoblasts at the G1 phase was significantly lower and the indexes of the osteoblasts at the S phase and G2-M phase were significantly increased after exposure to calcitonin (all P < 0.01). The OPG mRNA expression of the osteoblasts exposed to 80 IU/L calcitonin was significantly higher and the RANKL mRNA expression was significantly lower compared with the control group (P < 0.05). The OPG protein expression of the osteoblasts exposed to 80 LU/L calcitonin was significantly higher than that of the control group at different time points (P < 0.05, P < 0.01). CONCLUSION: Calcitonin increases the osteoblast proliferation and the OPG mRNA expression in the osteoblasts while RANKL mRNA expression in the osteoblasts is inhibited.

Role of carbonyl sulfide in acute lung injury following limb ischemia/reperfusion in rats.

OBJECTIVE: To investigate the effect of carbonyl sulfide (COS) on limb ischemia/reperfusion (I/R)-induced acute lung injury (ALI) and the associated mechanism in rats. METHODS: ALI was induced by bilateral hind limb I/R in Sprague-Dawley (SD) rats. Sixty-four SD rats were randomly divided into the control group, I/R group, I/R + COS group, and I/R + AIR group. We observed the survival rate of the rats and the morphological changes of lung tissues, and we measured the change in the lung coefficient, the expression levels of the intercellular adhesion factor-1 (ICAM-1) protein in lung tissue, the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-lß, and interleukin (IL)-6 in both lung tissue and serum, and cell apoptosis. RESULTS: Limb I/R caused significant lung tissue damage. The number of polymorphonuclear neutrophil in alveolar septa, the expression level of the ICAM-1 protein in lung tissue, the expression levels of TNF-α, IL-1, and IL-6 in lung tissue and serum, the lung coefficient, and cell apoptosis all increased. When a low dose of COS gas was administered prior to limb I/R, the variation of the above indicators was significantly reduced, while an increase in the dose of COS did not reduce the lung injury but rather increased the mortality rate. CONCLUSION: Carbonyl sulfide is another new gaseous signaling molecule, and a low dose of exogenous COS may play a protective role in I/R-induced ALI by acting as an anti-inflammatory agent by promoting the production of antioxidants and by inhibiting the expression of adhesion molecule proteins.