BACKGROUND:The polylactic acid/poly plycolic acid (PLGA) exhibits excellent biomechanical property with poor cell adhesion. However,acellular cartilaginous matrix had good cell adhesion and hydrophilia,which can mediate signal conduction and interaction among cells,yet the biomechanical property,is poor. PLGA-acellular cartilaginous matrix scaffold is a remedy for their shortcomings,which can be a newly scaffold materials. OBJECTIVE:To observe the ability of PLGA,acellular cartilaginous matrix,PLGA-acellular cartilaginous matrix scaffold in supporting the growth of porcine chondrocytes for cartilage tissue engineering. DESIGN,TIME AND SETTING:The comparative observation experiment was performed at the Laboratory of Shanxi Medical University from March to September 2008. MATERIALS:The average aperture of PLGA is from 100 -200 ?m,with porosity rate of 94%. The average aperture of the acellular matrix scaffold ranged 70-100 ?m,with porosity rate of 85%. The average aperture of PLGA-acellular matrix aperture is 100-300 ?m,and the porosity rate is approximate 90%. METHODS:The experiment was divided into three groups according to the scaffolds:PLGA,acellular cartilaginous matrix,and PLGA-acellular cartilaginous matrix group. The free chondrocytes isolated from porcine knee articular were seeded onto 3 kinds of scaffolds after cartilage amplification,followed by 8 weeks culture in vitro. MAIN OUTCOME MEASURES:The expression of type Ⅱ collagen was detected by immunohistochemistry. The contents of mRNA of type Ⅱ collagen were determined by RT-PCR. Meantime,the content of DNA was measured by Hoechst 33258 method. RESULTS:Chondrocytes grows vigorous on the PLGA-acellular cartilaginous matrix scaffold,which can maintain phaenotype after 8 weeks of culture,and the secretion of type Ⅱ collagen was superior to other 2 groups. Meanwhile,the content of DNA and mRNA of type Ⅱ collagen of PLGA-acellularcartilaginous matrix groups were greatest,followed by acellular cartilaginous matrix group,and the content of PLGA was smallest. The one-factor analysis of variance showed the difference had significant (P

Objective To identify and clone rat aging-related genes to provide clues for human aging mechanism. Methods Improved different display reverse transcript-PCR method was applied to identify differentially expressed genes in cortex tissues of 4-month and 24-month old BALB/c mouse. Results Forty-two cDNA fragments with differential expression were identified, and 21 with increase and 21 with decrease of expression in old mice. Among them, 17 represented genes with known protein function, 12 represented known gene sequences but their protein function was unknown, and the other 13 probably belonged to new cDNAs. Among the genes with known protein function, 2 genes were associated with oxidative stress, 3 with energy production, and 4 with protein metabolism, respectively. Additionally, gene expression alterations were also found in those related to cell apoptosis, neurodegenerative disorder, and growth and development regulation. Conclusions Rat aging might be related with the alteration of oxidative stress status, energy production and protein metabolism.

10.3969/j.issn.2095-4344.2013.26.011

Objective To investigate the relationship between apolipoprotein E (ApoE) ε4,ε2 alleles and intrauterine growth.Methods ApoE genotypes of 1418 people born in Peking Union Medical College Hospital were analyzed,allele frequencies were calculated and their parameters at birth were collected.To compare ApoE ε4,ε2 alleles with parameters at birth through single factor analysis and Logistic regression analysis.Results The alleLic frequencies of e2,83 and 84 were 8.11%,83.39% and 8.50% in the group.The results of single factor analysis showed that there was significant difference between the distribution of ponderal index (PI) in the ApoE ε2 allele group(χ2=4.87 ,P=0.027).While there was no significant difference between the distribution of head circumference at birth,placental weight and gestational age in the ApoE ε2 allele group.ApoE ε2 allele showed negative correlation with small PI in the logistic regression analysis(χ2=5.077 ,P=0.024),after adjusted for gender,age,head circumference at birth,placental weight,gestational age,parity and maternal age at delivery.No association between ApoE ε4 allele and parameters at birth was found.Conclusions ApoE ε2 allele may have protective effect on PI.No association was found between ApoE ε4 allele and intrauterine growth.

Objective To compare the efficiency of enhanced T2* weighted angiography (ESWAN) sequence with that of a conventional T2*-weighted gradient-recalled-echo (GRE T2*WI) sequence for the detection of hemorrhagic shearing lesions in patients with diffuse axonal injury (DAI). And combined with MRI parameters, to further discuss the principles and virtues of ESWAN sequence. Methods Seventeen patients with DAI were enrolled in this study. The raw data acquired from ESWAN scan were postprocessed by using the mean square root of multi-echoes. Then, the postprocessed images were compared with the conventional GRE T2* weighted images. The global and regional (superficial, deep and posterior fossa) lesion numbers determined by both sequences were compared by using Wilcoxon signed ranks test (two-tailed). Differences were considered to be significant at P≤0.05. Results Hemorrhagic lesions were more obvious on ESWAN images than those on conventional GRE T2* weighted images. The median and range value of the detected lesion numbers on ESWAN images were 27 and (1-239) in whole brain, 13 and (1-89) in cerebral superficial region, 5 and (0-111) in cerebral deep region and 1 and (0-39) in posterior fossa region, respectively; whereas, on GRE T2* weighted images, they were 7 and (1-34) in whole brain, 5 and (1-27) in cerebral superficial region, 2 and (0-25) in cerebral deep region and 0 and (0-4) in posterior fossa region, respectively. There were significant statistical differences between the two sequences in revealing the lesions in all the four regions (Z=-3.519,-3.182,-3.185,-2.677,P＜0.05). Conclusion In ESWAN sequence, multi-echo acquisition ensured sufficient magnetic susceptibility for detecting small hemorrhagic lesions. So, ESWAN is more sensitive to small hemorrhage, which revealed more hemorrhagic lesions than conventional GRE T2*WI and presented more valuable information for the diagnosis of DAI.

Objective To evaluate the feasibility of contrast material on image quality of coronary CT angiography (CCTA)by using double injection technology and iterative reconstruction.Methods 120 patients with suspected coronary heart disease who underwent CCTA were randomly divided into two groups.Then,60 patients with 30 kg/m2>BMI≥25 kg/m2 were averagely divided into A1 and B1 groups,and other 60 ones with BMI<25 kg/m2 were also averagely divided into A2 and B2 groups.The patients in group A were scanned with 120 kV tube output and iolromide 350 mg I/mL,and the images were reconstructed using filtered back projection (FBP).Meanwhile,the patients in group B were scanned with 80 kV or 100 kV tube output and 245 mg I/mL or 280 mg I/mL of contrast media (BMI≥25 kg/m2 )using double injection technology,and the images were reconstructed using adaptive iterative dose reduction 3D (AIDR 3D).The effective radiation dose (ED)of each patient was also calculated.CT attenuation of the main proximal vessels (ascending or descending aorta,pulmonary artery,RCA,LM,LAD and LCX)and the obj ective image quality (SD,CNR and SNR)were measured,and the subj ective evaluation was also assessed by an experienced radiologist.Results There was significant differences in mean image quality scores,SD,SNR and CNR of ascending aorta between group A1 and B1(P<0.05),but no difference in the SI of values (P>0.05).There was no significant difference in mean image quality scores between group A2 and B2 (P>0.05), however,there were significant differences in the SI,SD of values and SNR,CNR of ascending aorta (P<0.05).The values of BMI were negatively related to the values of CT in ascending aorta between two subgroups (r=-0.66 and -0.441,P<0.05).The values of weight were not related to the values of CT in ascending aorta (P>0.05).There was significant difference in effective dose between subgroups (P<0.05).Conclusion The method with a combination of iterative reconstruction and a contrast material of 245 mg I/mL using double inj ection technology can improve the contrast enhancement without impairing image quality.

Objective Through observing the change of serum cTnT level and other biochemical markers such as T3 and TNF-αin acute ischemic stroke patients , to investigate the correlation between the indictors change and short-term prognosis and stroke severity .Methods This study observed 68 patients (male 35 cases ,mean age 68 ±11.4 years; female 33 cases, mean age 69 ±10.3 years).All cases were collected fasting blood sample to test cTnT ,T3 and TNF-α.Death and other unexpected events were recorded in the form of telephone follow-up within one month in survival patients during and discharge from hospital.Results According to cTnT detection level ,all cases were divided into two groups , normal group (54 cases,79.4%) and positive group(14 cases,20.6%).There was statistical significance between posi-tive cTnT and NIHSS score neurological deficits ( p <0.01).cTnT was negratively correlated with T3( r =-0.324 , P <0.05 ) ,but positively with TNF-α( r =0.67 , P =0.017 ) .All patients were followed up for one month.14.7%patients died including 11.7%during hospital and 3% after discharge.After age, NIHSS adjustment cTnT remains an independent risk factor for death ( RR=2.34 ,95%CI=1.22-5.02 , P<0.01 ) .Conclusion After acute ischemic stroke , cTnT is correlated with dropping T 3 level and in-creasing TNF-αlevel, suggesting that both stress and inflammatory response may be involved in heart dam-age.Abnormal elevation of cTnT influenced short-term prognosis of acute ischemic stroke , which can be used as short-term indicators of poor prognosis in the clinical observations .

Objective To compare the clinical results of distal clavicular anatomical plates and clavicular hook plates in treatment of distal clavicular fractures.Methods Twenty-six patients with lateral 1/3 clavicular fractures of Craig Ⅱ type Ⅱ or Ⅴ treated from August 2009 to January 2011 were enrolled in the study.Eleven patients were managed by anatomic plates,including eight patients with type Ⅱ fractures and three with type Ⅴ fractures,while the rest 15 patients were treated by clavicular hook plates,including 11 patients with type Ⅱ fractures and four with type Ⅴ fractures.General information of the two groups was comparable before operation.Shoulder function after operation was evaluated by Constant-Murley score system.Postoperative radiographic findings and complications of patients in the two groups were studied comparatively.Results The distal clavicular anatomical plate group presented a lower incidence of shoulder pain and better mobility of shoulder,as compared with the clavicular hook plate group,but there were no significant differences in incision infection and implant loosening between the two groups.According to the Constant-Murley evaluation standard,excellence rates of the distal clavicular anatomical plate group and clavicular hook plate group were 91％ and 73％,respectively.Conclusion The distal clavicular anatomical plate is conducive to decrease of incidences of shoulder pain,increase of range of motion of shoulder and reduction of complications for treatment of Craig Ⅱ type Ⅱ or Ⅴ distal clavicular fractures and hence is in favor of early functional recovery of the limbs.

Minocycline is the second generation semisynthetic tetracycline antibiotics.A variety of animal models and clinical trials have shown that it has neuroprotective effect.Its mechanism is associated with inhibiting apoptosis, alleviating inflammatory reaction, reducing infarct volume, and alleviating vascular injury.This article reviews the neuroprotective effect of minocycline in preclinical phase and early clinical trials of acute ischemic stroke.

BACKGROUND: Tibia open fracture is a common disease, and intramedullary fixation has become the first choice, but the high risk of postoperative infection limits its clinical application.OBJECTIVE: To investigate the early prevention effect of vancomycin-hydroxyapatite (VCM-HA) coated titanium intramedullary nail in a rabbit model of open femoral fracture combined with wound infection.METHODS: Titanium intramedullary nails coated with three different concentrations of VCM-HA were prepared using biomimetic deposition, and subsequently in vitro bacteriostasis experiment was performed. Forty healthy male New Zealand white rabbits were selected and the model of mid-femur open fracture with wound infection was prepared. The rabbit models were then divided into ordinary intramedullary nail, low-, middle- and high-concentration VCM-HA coated intramedullary nail groups (n=10 per group). The wound appearance of the animals was dynamically observed. The body mass, anal temperature, white blood cells and C-reactive protein contents in the venous blood were monitored. The pathological examination of the soft tissue around the fracture and injured limb X-ray were conducted regularly.RESULTS AND CONCLUSION: The prepared VCM-HA coated titanium intramedullary nail exerted obvious antibacterial effects in vitro. The anal temperature in the ordinary nail group was significantly higher than that in the other three groups at 3 days after modeling (P < 0.05). The white blood cells and C-reactive protein contents in the venous blood in the VCM-HA groups were significantly lower than those in the ordinary nail group at 3, 7, 14 and 28 days after modeling (P < 0.05). The hematoxylin-eosin staining of the peripheral tissues displayed the inflammatory response in the VCM-HA groups was milder than that in the ordinary nail group at each time point after modeling. The injured limb X-ray displayed that the callus grew slowly accompanied with sequestration in the ordinary nail group, while the callus growth in the VCM-HA groups was significantly better than that in the ordinary nail group. To conclude, the VCM-HA coated intramedullary nail can effectively reduce postoperative infection in an animal model of open femoral fracture combined with wound infection.