Objective To explore the treatment method and clinical effect of LARS artificial ligament in treatment of combined anterior cruciate ligament(ACL) and posterior crueiate ligament (PCL) injuries of the knee under arthroscope. Methods Thirteen cases of ACL and PCL injuries were reconstructed with LARS ligament. The patients were followed up for 12-36 months. The International Knee Documentation Committee (IKDC) and Lysholm knee score scale were used for functional evaluation. In the meantime, KT-1000 was employed to check anterior and posterior laxation of the knee. Results No knee infection or limitation of knee extension occurred. Knee flexion was 105° -125° (average 117°). At termination of follow up, 10 cases (77%) was graded as A and 3 (23%) as B according to IKDC. KT-1000 examination at 25° flexion showed that the difference of anterior laxation was less than 2 mm in 12 cases and 3-5mm in 1. KT-1000 examination at 70°flexion showed that the difference of anterior laxation was less than 2mm in 12 cases and 2-4 mm in 1. The Lysholm score was (63.8±2.9) points (49459 points) before operation and (91.1 ±2.7) points (88-95 points) at follow up, with statistical difference (P ＜0.01). Conclusion Reconstruction of ACL and PCL by using LARS ligament under arthroscope is a kind of minimally invasive, safe and effective method to treat ACL and PCL injuries of the knee, with good short term outcome.

Objective To understand the ‘ problem behavior' and influencing factors during job haunting of medical students and to provide guidance for students.Methods Totally 409 medical students who had graduated or were going to graduate but all having the experiences of applying for jobs were surveyed with self-made questionnaire.Likert 5 points scoring method was employed to evaluate the job hunting and SPSS 17.0 seftware was used to do statistical analysis.Results The ‘ problem behaviors' with the highest scores were conformism and comparison [(3.93 ± 0.628) and (3.80 ± 0.847) respectively)].Self factors influencing students' behavior in career choice included the capacity for self-definition (3.62 ± 0.855),personal values (3.55 ± 0.893) and legal awareness (3.51 ± 1.039).Meanwhile,the factor with the highest score was education cost (3.93 ± 0.887).Besides,influences of family expectation (3.43 ± 0.945),employment environment (3.40 ± 0.940) and college educational system (3.28 ± 1.038) were also outstanding.Conclusions Medical students'‘ problem behaviors' during job hunting are diverse and are influenced by many factors.So,we are supposed to strengthen the education and guidance from the self factors,combining the actions of school,family and society to promote medical students' employment.

BACKGROUND:It is controversial to treat sacroiliac joint fracture.Some scholars advocated expectant treatment,and some others advocated surgery therapy.Pelvic stability was responsible for the scheme selection.Sacroiliac joint fracture-dislocation destroys pelvic stability,which easily induces instability and bone nonunion,resulting in sacroiliac joint pain,unequal size of lower limbs,sitting pain and dysfunction.Thus,prognosis of mental implant is significantly better than expectant treatment in treatment of unstable pelvic fracture.OBJECTIVE:To summarize the treatment of unstable pelvic fractures and their clinical application using various internal and external fixation of metal implants.METHODS:The computer-based research was done in Pubmed database (http://www.ncbi.nlm.nih.gov/PubMed) and Wanfang database (http://www.wanfangdata.com.cn) for articles published from January 1991 to December 2009 with the key words of "Pelvic fractures,instability,surgical treatment" by the first author.A total of 115 articles were retrieved,and those concerning characteristics and clinical application of implants in the treatment of unstable pelvic fracture.Articles addressing old and repetitive contents were excluded.Literatures of the same fields published in recent years or in authorized journals were selected.Finally,30 articles were included.RESULTS AND CONCLUSION:Sacroiliac joint fracture-dislocation is a severe,high-energy trauma,has been paid great attention in the therapy,particularly in unstable sacroiliac joint fracture-dislocation.A stable type of fracture and dislocation of the sacroiliac joint received a conservative treatment of unstable sacroiliac joint fracture-dislocation appropriate line of external fixation,internal fixation for reconstruction of pelvic stability and internal fixation treatment varied,but the therapeutic effect of internal fixation needs to be improved.What are bio-mechanical characteristics of various internal fixation methods,and how the timing of weight-bearing activities following various internal fixations require further basic and clinical studies.An unstable sacroiliac joint fracture-dislocation fixation has many ways,including the anterior and posterior fixed-fixed.Minim ally invasive therapy such as posterior CT guided sacroiliac joint lag screw is the developmental trend.

BACKGROUND: Using low-intensity pulsed ultrasound (LIPU) to promote the repair of articular cartilage injury is very common,and we also have more options to choose the cytoskeleton, but the application conditions of LIPU and the appropriate cytoskeleton have not reached any consensus yet.OBJECTIVE: To investigate the feasibility of establishing tissue-engineered cartilage by cell-free allograft demineralized bone matrix (CFDBM) co-cultured with rabbit cartilage cells and bone marrow mesenchymal stem cells (BMSCs) in vitro, and to investigate the effect of LIPU on the cells in CFDBM.DESIGN, TIME AND SETTING: Multiple sample observation was performed at the Institute of Biomedical Engineering, Second Military Medical University of Chinese PLAfrom May to August 2009.MATERIALS: The CFDBM was prepared as modified Urist's method; the cartilage cells were obtained using mechanical disintegration and enzyme digestion; the BMSCs were separated using whole bone marrow rinsing method, purified, and amplified layer by layer.METHODS: As CFDBM With a composite of different cellular components, and whether applying LIPU stimulation, the samples were divided into four groups: chondrocyte group, BMSCs group, compound group (CFDBM was compounded with chondrocytes,BMSCs, and chondrocytes/BMSCs, respectively, without LIPU stimulation), and LIPU group (CFDBM was compounded with chondrocytes/BMSCs, and then the samples were stimulated with LIPU on the second day, 1.0 MHz frequency, 10 mW/cm~2 transient spatial intension, 20 min/d).MAIN OUTCOME MEASURES: ① the 2~(nd)-generation of cartilage cells and BMSCs were examined by immunohistochemical method; ② The CFDBM prepared as modified Urist's method was examined as HE staining; ③ The samples of four groups were examined by collagen II immunohistochemical staining on the 21~(st) day.RESULTS: ① The collagen II immunohistochemical staining of the second generation of the articular cartilage cells showed that the morphostructure was polygon, star or round, and pseudopodia extended, and the cells were rich in cytoplasm; the cytoplasm was brownish yellow, and the cell nuclear was round. ② The result of immunohistochemical staining of BMSCs showed that,CD34 was negative, CD44 and CD105 were positive. ③ In the center of CFDBM prepared as modified Urist's method, there was no obvious cell-like structure and the gap size was uniform. ④ On the 21~(st) day after combining CFDBM with cells, collagen II immunohistochemical staining demonstrated that BMSCs group was negative, chondrocyte group was weak positive, compoundgroup was positive, and the LIPU group was strongly positive.CONCLUSION: ① Biological property of the 1~(st)-3~(rd)-passage chondrocytes and BMSCs was similar to primary-cultured cells. ②Both chondrocytes and BMSCs had a highly proliferative ability in CFDBM. ③ 10 mW/cm~2 LIPU could not affect activity of BMSCs but could promote differentiation Into articular cartilage cells, and it also could not promote celt proliferation.

Objective To study on the CDKN2/P16 gene in primary osteosarcoma.Method By using molecular biological methods that inclued genome DNA extraction from paraffined tissue and PCR SSCP analysis technique, we studied alternations of CDKN2/P16 gene in 25 primary osteosarcomas.Results (1)The deletions frequency in differentiation degree of osteosarcomas was① bone brood cell, 16.7% ;② cartilage brood cell,12.5% ;③ Fiber brood cell:20% ,(P >0.05).(2)The deletion frequency in male patients was 17.6% , female patients 12.5% ,(P >0.05).(3)In early metastatic osteosarcomas the deletion rate was 33.3% ,which was significantly higher than that of the control group with the rate of 10.5% (P< 0.05).(4)The deletion rate was 16% and the mutations were not found.Conclusion (1)The deletion rate was 16% and the mutations were not found.This suggests that the deletions of CDKN2/P16 gene were closely related to the genesis of primary osteosarcoma and that the main type of the alternation of CDKN2/P16 gene was deletion.(2)In early metastatic osteosaarcomas the deletion rate was 33.3% , which was significantly higher than that of the control group with the rate of 10.5% .This indicates to great extend that the deletions of CDKN2/P16 gene were closely related to the metastatic ability.(3)The deletions frequency had no significant relationship with differentiation degree of osteosarcomas, so was with the sex of the patient.

27 rabbits were divided into normal group(n = 4),control group (n = 5), silybin group (n = 6), hyperbaric oxygen (HBO) group (n = 6), and HBO combined with silybin group (n = 6). Circulation of hindlimb was interrupted completely for 6 h and reperfused for 1 h. Malondialdehyde (MDA) and superoxide dismutase(SOD) in plasma from ischemic-reperfused injured limb were measured. Adenosine triphosphate (ATP) and creatine phosphate (CP) in samples taken from anterior tibial muscle were determined. Ultrastructural changes of injured muscle were observed. The results showed that HBO combined with silybin treatment had a favourable effect on ischemic and reperfused injured limb muscle with reduction of the lipid peroxidated injury, increase of the SOD activity and the high energy phosphate compounds (ATP and CP), and a promoting recovery of injured muscle cells. HBO and silybin had a synergistic action. It suggests that HBO combined with silybin is an effective method for treatment of ischemic and reperfused injured limb.

Elucidation of the signaling pathway mechanisms related to the mechanical stress-mediated bone regeneration is of great significance for improvement of bone regeneration and clinical treatment of bone-related diseases such as bone defects and bone elongation. Mechanical stress transmits mechanical stimuli into cells through the piezo channels and integrins, causing a variety of signaling pathway responses, which in turn changes transcription factor translocation, gene expression, and osteoblast differentiation to promote bone regeneration ultimately. This article reviews the research progress concerning the mechanisms related to mechanical stress-mediated bone tissue regeneration.

Background: Implant-supported dentures have become an essential means of restoring occlusal function after jaw reconstruction. Bone mineral density (BMD) may influence the success rate of implant denture restorations. This study aimed to explore whether the Hounsfield unit (HU) value can be used to monitor the changing trend of fibular BMD after jaw reconstruction. Results: A total of 54 patients who underwent maxillar/mandibular reconstruction with a fibula flap were included in this study. There was a significant correlation between the HU value and BMD at 1 week, 3 months, and 6 months after surgery, and both were significantly correlated with follow-up time. The difference between each pair of absorption rates (DAR) was less than 10% in 66.7% and 75.9% of patients at 3 and 6 months; however, the DAR was more than 20% in 12% and 13.8% of patients at 3 and 6 months, respectively. Conclusions There is a significant correlation between HU value and BMD. The HU value can be used to roughly reflect the fibular BMD changing trend in a group of patients as opposed to an individual, and the HU value is not equivalent to BMD.

Objective:To investigate characteristics and changes of skin microbiota in atopic dermatitis-like mouse models induced by different concentrations of 2,4-dinitrochlorobenzene (DNCB) .Methods:Totally, 30 male specific-pathogen-free BALB/c mice were randomly divided into 3 groups by using a random number table: negative control group topically treated with 200 μl of mixture of acetone and olive oil at a volume ratio of 3∶1 on the back twice a week for 6 consecutive weeks; high-and low-concentration DNCB groups both topically treated with 200 μl of 1% DNCB on the first and third day at the first week, followed by topical application of 200 μl of 0.5% and 0.1% DNCB, respectively, twice a week for 5 weeks from the second week. Twenty-four hours after the last treatment, the severity of skin lesions was evaluated, and the transepidermal water loss and stratum corneum hydration were measured. After the experiment, the mice were sacrificed, and skin tissues were resected from the back of the mice for histopathological examination. Full-thickness skin tissue samples were obtained from the back of 3 mice in each group. Illumina Miseq PE300 high-throughput sequencing was performed to sequence the V3-V4 variable region of 16S rRNA gene of skin microbiota on the back of the mice, and the composition and structure of the skin microbiota and changes in the relative abundance of different genera were analyzed. One-way analysis of variance was used to analyze differences in indices among the 3 groups, and the Games-Howell method was used for multiple comparisons.Results:The severity scores of skin lesions were significantly higher in the high-and low-concentration DNCB groups (9.83 ± 2.45 points, 2.71 ± 0.56 points, respectively) than in the negative control group (0.51 ± 0.12 points, t=-7.19,-2.85, respectively, both P < 0.05) . Compared with the negative control group, the high-and low-concentration DNCB groups showed significantly increased transepidermal water loss ( t=-7.72,-2.68, respectively, both P < 0.05) , but significantly decreased stratum corneum hydration ( t=6.77, 5.99, respectively, both P < 0.05) ; the transepidermal water loss was significantly higher in the high-concentration DNCB group than in the low-concentration DNCB group ( t=2.76, P < 0.05) , while no significant difference in the stratum corneum hydration was observed between the high-and low-concentration DNCB groups ( P > 0.05) . There was a significant difference in the relative abundance of Corynebacterium among the 3 groups ( F=249.85, P < 0.001) , which was highest in the high-concentration DNCB group. No significant differences in the observed species and Chao1 index of the skin samples were observed among the 3 groups (both P > 0.05) , and the Shannon index was significantly lower in the high-concentration DNCB group than in the low-concentration DNCB group and negative control group ( t=6.96,-6.37, respectively, both P < 0.05) . Conclusion:DNCB could induce atopic dermatitis-like dermatitis in mice, and the severity of skin lesions and degree of barrier function impairment were related to the concentration of DNCB; the species diversity of skin microbiota markedly decreased in the high-concentration DNCB group, indicating that high-concentration DNCB modeling has more advantages in studying microbiological changes associated with atopic dermatitis.

Myasthenia gravis crisis (MC) often involves respiratory muscles and requires mechanical ventilation urgently. As non-invasive mechanical ventilation (NIV) technology unceasing development, its use in acute respiratory failure caused by MC shows obvious advantages. However, how to identify the occurrence of MC at early stage, predict the relevant indicators of NIV for MC treatment, and apply different ventilation strategies to improve the effect of treatment are worthy of attention. In addition, the new development of NIV modes in recent years also provides new direction for the treatment of MC. Therefore, this article reviews recent advance in the clinical application of NIV in MC to provide clinical references.