Tendon injuries often need surgical treatment, which enables to repair the structure and stability of the tendons to a certain extent, whereas it is difficult to restore to their normal strength. The primary reason is that the natural healing ability of tendons is limited and the functions of the repaired tendons cannot be restored completely. As further researches on tendon healing are conducted, biological technology provides a novel orientation for tendon repair. One of the research hotspots of tendon repair currently is to facilitate tendon healing using biological auxiliaries, including tendon stem /progenitor cells(TSPCs) and growth factors. The authors review the research progress in mechanism of TSPCs and growth factors accelerating tendon healing in order to provide a reference for the biological treatment of tendon injuries.

Objective:To study the effect of microglia depletion combined with bone marrow mesenchymal stem cells (BMSC) transplantation for spinal cord injury (SCI) repair.Methods:GFP-BMSCs were cultured, identified and detected for expression levels of growth factors. The effects of BMSCs ondorsal root ganglion (DRG) axon outgrowth were observed by the co-culture of BMSCs with DRGs. Mice were depleted of microglia by administrating the colony stimulating factor 1 receptor (CSF1R) inhibitor PLX3397. The spinal cords of these microglia-depleted mice were subjected to crush injury. BMSCs were transplanted into SCI area after microglia depletion. Mice were randomly divided into control group (SCI+BMSCs) and experimental group (PLX3397+SCI+BMSCs). Mice were sacrificed at corresponding time points after transplantation for observing the survival of transplanted BMSCs and the repair of spinal cord. BMS score was used for evaluation of motor function recovery.Results:BMSCs secreted a large number of neurotrophic factors and promoted the growth of DRG axons when co-cultured with DRGs. Depletion of microglia significantly improved the survival of transplanted BMSCs. Compared with BMSCs transplantation alone, the combined treatments slightly but non-significantly reduced the area of the lesion ( t=2.141, P=0.065). Immunofluorescence staining showed that both BMSC transplantation alone and the combined treatments did not cause the corticospinalaxons across the lesion and into distal spinal cord. BMS scores were (1.20±0.45), (3.20±0.45), (3.80±0.45), (4.20±0.45), and (4.60±0.55) points in control group at 1, 7, 14, 21 and 28 d after injury. The experimental groups were(0.60±0.55), (3.00±0.71), (3.80±0.84), (4.20±0.84), and (4.40±0.89) points, respectively. Conclusion:Depletion of microglia improves the survival of transplanted cells, depletion of microglia combined with BMSC transplantation did not result in a significant reduction in lesion area. At the same time, the damaged CST axons were notregenerated. Thus, combining cell transplantation with axon-promoting strategy may be necessary for SCI repair.

Objective:To explore the clinical effectiveness of arthroscopic treatment of tibial eminence avulsion fracture by four-point fixation with suture anchors.Methods:A retrospective analysis was performed of the 58 patients with tibial eminence avulsion fracture who had been treated by the same group of surgeons using four-point fixation technique with suture anchors under arthroscopy at Department of Sports Medicine, The Affiliated Hospital to Qingdao University from January 2015 to December 2018. They were 33 males and 25 females, with an average age of 18.4 years (from 14 to 32 years). By the modified Meyers-McKeever classification, 15 fractures were type Ⅱ, 19 type Ⅲ and 24 type Ⅳ. Recorded and compared were knee Lysholm scores, International Knee Documentation Committee (IKDC) scores and tibial eminence height between preoperation and one year postoperation; recorded at the last follow-up were range of knee motion and results of Lachman and pivot-shift tests.Results:The 58 patients were followed up for a mean of 20.7 months (from 12 to 33 months). Bony union was achieved in all patients within 12 weeks after operation. In this cohort, the Lysholm score (85.2±4.9) and IKDC score (86.2±4.3) at one year postoperation were significantly higher than the preoperative values (43.2±5.2 and 51.2±4.9), and the post-operative tibial eminence height [(9.1±1.2) mm] was significantly lower than the preoperative value [(12.6±1.2) mm] (all P<0.05). The correlation coefficients between the tibial eminence height and the Lysholm & IKDC scores at one year postoperation were -0.16 and -0.17, respectively. The last follow-up showed a 132°±5° range of knee motion for all patients, a positive result of pivot-shift test (grade Ⅱ) for 3 and a positive result of Lachman test (grade Ⅰ) for 2. Conclusion:Arthroscopic treatment of tibial eminence avulsion fracture by four-point fixation with suture anchors can lead to satisfactory effectiveness, showing advantages of minimal invasion, anatomic reduction, reliable fixation, and little impact on the epiphysis plate.

Objective:To investigate the early outcome of endoscopy-assisted percutaneous non-fusion fixation of unilateral C 1 lateral mass screw and C 2 pedicle screw in treatment of type II odontoid fracture in elderly patients. Methods:A retrospective case series study was conducted to analyze clinical data of 12 elderly patients with type II odontoid fracture admitted to Second Affiliated Hospital of Chongqing Medical University from July 2016 to September 2018. There were 5 males and 7 females, aged 66-89 years [(75.2±6.7)years]. American Society of Anesthesiologists (ASA) scores for all patients were greater than 2 points. Ten patients were classified to Grade E and the other two were classified to Grade D by American Spinal Injury Association (ASIA) scale scores. All patients underwent endoscopy-assisted percutaneous non-fusion fixation of unilateral C 1 lateral mass screw and C 2 pedicle screw. The operation time, intraoperative blood loss, hospital stays, intraoperative and postoperative complications were collected. The Neck Disability Index (NDI) scores and ASIA scale scores were compared preoperatively and 6 weeks postoperatively. The visual analogue scales (VAS) were recorded preoperatively, 6 weeks, 3, 6, 9 and 12 months postoperatively. Fracture healing was followed up postoperatively. Results:Operation time was 98-169 minutes [(123.2±17.7)minutes]. Intraoperative blood loss was 20-40 ml [(30.0±7.1)ml]. Hospital stays were 6-9 days [(7.3±0.7)days]. No neurovascular injury was observed intraoperatively and postoperatively. The NDI were 8%-30%[(19.3±6.3)%] 6 weeks postoperatively, significantly lower than 19%-45%[(33.1±9.9)%] preoperatively( P<0.05). All patients' ASIA scale scores reached grade E postoperatively. The VAS constantly decreased from 6-9 points [(7.8±0.9)points] preoperatively to 1-3 points [(1.8±0.6)points] 12 months postoperatively ( P<0.05). All the patients achieved bone healing after 4-11 months [(7.3±2.1)months]. Conclusion:For type II odontoid fracture in elderly patients, endoscopy-assisted percutaneous unilateral atlantoaxial screw non-fusion fixation can relieve pain and achieve rapid recovery of neck function and bone healing.

Objective To investigate the etiological and antibiotic resistance profile in the old patients with bloodstream infection (BSI).Methods Microbiological and clinical data were collected and reviewed retrospectively for the patients with confirmed bloodstream infection and at least 65 years of age who were treated as inpatients in Tongling People′s Hospital from January to December 2015.Results A total of 107 strains of pathogen were isolated from the blood samples of 107 patients with bloodstream infections, of which community-acquired BSI accounted for 57.9 % (62/107), and hospital-acquired BSI 42.1 % (45/107). Gram negative bacilli accounted for 67.7 % in the pathogens of community-acquired BSI and gram positive cocci accounted for 55.5 % in the pathogens of hospital-acquired BSI. More male BSI patients were secondary to respiratory tract infection than female patients (P<0.001), while more female BSI patients were secondary to urinary tract infection than male patients (P<0.001). Of the 107 isolates, gram negative bacilli, gram positive cocci and fungi accounted for 55.1 % (59/107), 42.1 % (45/107) and 2.8 % (3/107), respectively. The top six pathogens were E. coli (30.9 %), coagulase negativeStaphylococcus (CNS) (20.6 %), S. aureus (10.3 %),K. pneumoniae (6.5 %),Enterococcusspp. (6.5 %) and Acinetobacter spp. (4.7 %). About 51.5 % of the E. coli isolates and 28.6 % of the K. pneumoniae isolates produced extended-spectrum β-lactamases (ESBLs).E. coli isolates showed low resistance rate (< 10 %) to amikacin,cefoxitin and piperacillin-tazobactam. No E. coli isolate was found resistant to carbapenem. About 14.3 % to 28.6 % of K. pneumoniae isolates were resistant to carbapenems. No tigecycline-resistant K. pneumoniae was found. The prevalence of MRSA and MRCNS was 36.4 % and 72.7 %, respectively. No staphylococcal isolates were found resistant to vancomycin, teicoplanin or linezolid. One strain of E. faecium was identified as resistant to vancomycin (VRE).Conclusions This surveillance data indicate that gram negative bacilli play an important role in the BSI of old patients. E. coli and CNS are the most common pathogens. We should pay more attention to the effect of gender and site of infection on the BSI in old patients.

Objective To compare the clinical value of two kinds of imaging methods including CT and MRI in early diagnosis of acute multiple cerebral infarction. Methods The imaging data of CT and MRI of 108 patients with acute multiple cerebral infarction were analyzed. The total detection rate, the detection rate in different time periods,the number and area of detected lesions and the inspection time of CT and MRI in early diagnosis of acute multiple cerebral infarction were compared. Results The total detection rates of patients with acute multiple cerebral infarction by CT and MRI were 57. 41%,96. 30%,respectively. The total detection rate of MRI was significantly higher than CT(χ2 =9. 73,P<0. 05). The detection rates of patients with acute multiple cerebral infarction for onset within 24h and 24-72h by MRI were significantly higher than CT(χ2 =18. 54,16. 20,all P<0. 05). There was no significant difference in detection rate of patients with acute multiple cerebral infarction for onset >72h between CT and MRI(P>0. 05). The number of detected lesions of patients with acute multiple cerebral infarction by MRI was significantly more than CT(t=2. 39,P<0. 05). The area of detected lesions and the inspection time of patients with acute multiple cerebral infarction by MRI were significantly less than that by CT(t =2. 43,2. 60,all P <0. 05). Conclusion Compared with CT, MRI in the early diagnosis of acute multiple cerebral infarction can effectively improve the detection rate in early stage, avoid the missed diagnosis of small lesions and is helpful to shorten the examination time.

BACKGROUND:Bacterial biofilm is the main cause of the infection of the prosthesis.In vitro experiments confirmed that hypertonic sodium chloride and ethanol can apparently promote the formation of staphylococcal biofilms. There are no reports on the effects of ethanol and hypertonic environment surrounding the prosthesis on the formation of biofilms.
OBJECTIVE: To evaluate the effects of different environment factors surrounding the prosthesis on the growth of Staphylococcus epidermidis and bacterial biofilm formation after replacement.
METHODS: White rabbit models infected with Staphylococcus epidermidis on the prosthesis were established, and were randomly divided into hypertonic sodium chloride, ethanol and control groups (n=15). The bacteria were injected with 0.1 mL 4% sodium chloride and 4% ethanol into the knee of rabbits in the hypertonic sodium chloride and ethanol groups. The rabbits were injected with 0.1 mL 0.9% sodium chloride in the control group. Three rabbits were sacrificed at 2, 4, 6, 8 and 16 days after inoculated with bacteria. Synovial fluid, prosthesis and tissue surrounding infection were obtained. Bacterium was cultured to extract total RNA. The ica operon transcription levels were detected in the gene levels. Adhesion of bacteria on the surface of the prosthesis was observed using a scanning electron microscope. Tissues surrounding the prosthesis were observed using hematoxylin-eosin staining.
RESULTS AND CONCLUSION:Histological examination revealed that inflammatory cel infiltration was observed in al the rabbits at 4 days after injection. Colony formation was found at 16 days after injection. At 6 days after injection, inflammatory cel infiltration was observed in the ethanol and control groups. Scanning electron microscope showed that compared with the control group, the bacteria adhered to the prosthetic surface became more in the hypertonic sodium chloride and ethanol groups at 6, 8 and 16 days (P < 0.05). At 6, 8 and 16 days, the expression of icaA mRNA was significantly higher in the hypertonic sodium chloride and ethanol groups than in the control group (P < 0.05). These data showed that the environment factors could affect the growth of Staphylococcus epidermidis and bacterial biofilm formation.

Objective To investigate the bacterial resistance of clinical isolates collected in Tongling area. Methods Antimicrobial susceptibility test was conducted by Kirby-Bauer method.All the data were analyzed with WHONET 5.5 software.Results A total of 3 092 clinical isolates were collected during 2012,of which gram negative organisms and gram positive organisms accounted for 76.3% (2 359/3 092)and 23.7% (773/3 092),respectively.MRSA and MRCNS accounted for 50.9% of S.aureus and 73.0% of coagulase negative Staphylococcus,respectively.MRSA and MRCNS showed higher resistance to gentamicin,ciprofloxacin and erythromycin.No vancomycin-or teicoplanin-resistant strains of Staphylococcus spp.were found.No vancomycin-or teicoplanin-resistant strains of E.faecalis were found.Some E.faecium strains were resistant to vancomycin and teicoplanin.About 52.1% of E.coli isolates and 42.1% of Klebsiella isolates produced extended-spectrumβ-lactamases (ESBLs).Imipenem-or meropenem-resistant strains of K. pneumoniae were found. The percentage of P.aeruginosa strains resistant to amikacin, cefoperazone-sulbactam and cefepime was 3.4%,14.0% and 17.7%,respectively.More than 70% of Acinetobacter spp. strains were resistant to all the antibiotics tested except minocycline and cefoperazone-sulbactam,to which 42.1%and 4.4% of the strains were resistant.Conclusions The antibiotic resistance of clinical bacterial isolates is growing. The spread of multi-drug or pan-drug resistant strains in a specific region poses a serious threat to clinical practice.We should pay more attention to resistance surveillance and the rational use of antibiotics.

Objective To investigate the bacterial resistance of clinical isolates collected in Tongling area during 2011.Methods Antimicrobial susceptibility testing was conducted by Kirby-Bauer method.All the data were analyzed by WHONET 5.5 soft-ware.Results A total of 2 690 clinical isolates were collected during 2011,of which gram negative organisms and gram positive organisms accounted for 74.2% and 25.8%,respectively.MRSA and MRCNS accounted for 45.1% of S.aureus and 71.6%of coagulase negative Staphylococcus,respectively.MRSA and MRCNS showed higher resistance to gentamicin,ciprofloxacin and erythromycin than the corresponding methicillin-susceptible strains.No vancomycin- or teicoplanin-resistant strain of Staphylococcus spp.was identified.The resistance rate to penicillin,nitrofurantoin and fosfomycin was low in E.faecalis.No ampicillin-,vancomycin-or teicoplanin-resistant strains were found.For E.faecium,some strains were resistant to vancomy-cin and teicoplanin.About 46.6% of E.coli isolates and 27.7% of Klebsiella isolates produced extended-spectrumβ-lactamas-es (ESBLs).No imipenem-or meropenem-resistant isolate was found.The percentage of P .aeruginosa strains resistant to imipenem,meropenem and amikacin were 29.5%,36.9%and 2.3%, respectively. More than 60.0% of the Acinetobacter strains were resistant to all the antibiotics test-ed except minocycline and cefoperazone-sulbactam,to which 26.4% and 12.5% of the strains were resistant.Conclusions No glycopeptides-resistant isolate was found in gram positive organisms except E.faecium.The resistance rate of Enter-obacteriaceae isolates was lower to imipenem,meropenem, cefoperazone-sulbactam,piperacillin-tazobactam and amika-cin.The prevalence of resistant strains is still increasing,es-pecially carbapenem-resistant P .aeruginosa and carbapenem-resistant A.baumannii.It is mandatory to take effective antibiot-ic policy and infection control measures.