Objective To evaluate the value of MRI in acute ankle distortion without evidence of fracture. Methods The MRI appear-ances of 21 cases with acute trauma in the ankles were retrospectively analyzed,focusing on the presence or absence injuries of lateral collat-eral ligamentous complex,bone and osteochondral lesions,MRI was performed within 48 h of trauma. Results Bone bruise was observed in 15 patients. There were injuries of the lateral ligaments in 4 cases and the medial ligaments in 1 case. Injury of the osteochondral lesion was in 5 cases and Achilles tear was in 3 cases. Conclusion MRI have diagnostic value for acute ankle injury.

Objective To investigate the effect of phosphatidylinesitol-3 kinase/serine threonine kinase (PI3K/Akt) signaling pathway on expression of beta-site amyloid precursor protein cleaving enzyme-1 (BACE1) in the hippocampus neurons of rat brain. Methods Forty SD rats were randomly divided into 4 groups: blank control group, sham-operated group, insulin group and wortmannin group. Insulin or the specific inhibitor of PI3K, wortmannin was injected into hippocampus neurons to activate or inhibit the signaling pathway in insulin group or wortmannin group, respectively. Immunoprecipitation and Western blot were used to analyze the proteins levels of PI3K/Akt and BACE1. Results In insulin treatment group,among the proteins downstream of signaling pathway, expression of Akt increased (0. 952±0.060 vs 0.835±0.029,t=4.9150, P=0.0001), phospho-Akt set473 increased (0.800±0.075 vs 0.657± 0.025,t=4.5598, P=0.0002), phospho-GSK-3α decreased (0.604±0.062 vs 0.726±0.041, t= 3.5871, P=0.0018 ), and the expression of mature BACE1 and β-CTF significantly decreased. In wortmannin group, the expression of Akt and phospho-Akt ser473 were inhibited; phospho-GSK-3α increased ; mature BACEI (1.004±0.096) and β-CTF (1.031±0.048) increased (t=11.5980, P= 0.0000 and t =4.2194, P =0.0004, respectively). Conclusions PI3K/Akt signaling pathway might effect the expression of BACE1, in which impaired signaling pathway may cause the amyloid precursor protein to be easily processed by BACE1, and thus involves the pathology of Alzheimer' s disease.

Objective To evaluate the clinical results of free vascularized fibular grafting (FVFG) for the treatment of osteonecrosis of the femoral head (ONFH).Methods From July,2009 to January,2013,85 cases (120 hips) of ONFH were treated with free vascularized fibular grafting.These cases included 61 males (87 hips) and 24 females (33 hips) with an average age of 36.5 years (22-51 years);7 hips (Ⅰ A 2 hips,Ⅰ B 3 hips,Ⅰ C 2 hips) were at stage Ⅰ,98 hips (Ⅱ A 24 hips,ⅡB 39 hips,ⅡC 35 hips) at stage Ⅱ and 15 hips (ⅢA 9 hips,ⅢB 4 hips,Ⅱ C 2 hips) at stage]Ⅲ according to the classification system of Association Research Circulation Osseous (ARCO).The mean preoperative Harris hip score was (60.21±6.85) points (42-71 points),The follow-up items included the X-ray examination,the Harris scores of the hip,and the evaluation of the complications.Results Eighty-three cases (117 hips) were followed up.The average duration of follow-up was 25 months (range from 12 months to 42 months).The mean postoperative Harris hip score was increased to (81.26±5.84) points (67-91 points) by the end of the follow-up,compared with the preoperation,the score improved significantly,the difference was statistically significant (P＜0.05).Comparing with postoperative X-ray,101 hips (86.3％) were improved,12 hips (10.3％) had no significant changes and deterioration occurred in 4 hips (3.4％).Conclusion The free vascularized fibular grafting is an effective method for treating osteonecrosis of and preventing the collapse of the femoral head.

Objective:To investigate the MRI features of perirenal space involvement in patients with acute pancreatitis (AP) and its correlation with disease severity.Methods:A total of 128 AP patients admitted to Bishan District People′s Hospital of Chongqing from June 2018 to June 2020 were selected as study subjects. All patients were diagnosed by ultrasound guided percutaneous biopsyand the pathological diagnosis results were taken as the gold standard. The accuracy, sensitivity and specificity of MRI diagnosis were calculated to analyze the correlation between MRI features of perirenal space involvement and MRI severity index (MRSI).Results:Among the 128 patients, 96 patients with perirenal space involvement in AP confirmed by ultrasound guided percutaneous biopsyand the pathological diagnosis results, accounted for 75.00%. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value diagnosed by MRI were 95.83%, 93.75%, 95.31%, 97.87% and 88.24% respectively. The involvement rate of perirenal space in AP was 75.00%(96/128), and that in mild, moderate and severe AP was 52.38%(22/42), 93.62%(44/47) and 7/7, respectively. Forty-two mild patients presented abnormal signals in the pancreas, or focal and diffuse pancreatic enlargement, thickening, and abnormal streak signalabnormalities in perirenal space, perirenal MRI showed grade 1 and 2. Forty-seven patients with moderate disease showed patchy signal abnormalities in the perirenal space, and perirenal MRI showed grade 3. Seven severe patients found perirenal interstitial effusion which was patchy. There was a good correlation between MRI features grade of perirenal space involvement and MRSI ( r = 0.721, P<0.001). The consistent rate of MRI features score of the right perirenal space was 91.14%, the consistent rate of MRI features score of the left perirenal space was 95.38%, and the consistent rate of MRSI observation on both was 90.21%. Conclusions:MRI can effectively and accurately diagnose perirenal space involvement in AP patients, MRI features and involvement rate can accurately reflect the severity of AP, which has a positive effect on clinical diagnosis and treatment of patients with perirenal space involvement in AP.

Objective To analyze the characteristics on demographical,spatial distribution and transmission mode of HIV infections among 50-year-old population.Methods Related information on demography,spatial distribution,high risk behavioral and history of HIV infections among 50-year-old population were collected and analyzed.Possible time of infection based on their first CD4 testing results right after the HIV diagnoses,was estimated.Results Since 2008,the number of new HIV/AIDS cases among the over-50-year-olds was reported increasing annually.The number of aged 50 and above in 2014 was 4.2 times than the number in 2008.50-year-old or older population were infected mainly through heterosexual behavior (88.0％).Among these cases,83.9％ self-reported as having histories on extramarital sex intercourse and the number was increasing yearly.Among male cases who admitted as having heterosexual experience,95.1％ of them reported as having histories of extramarital sex intercourse while 53.4％ of the female cases reported as having the same experiences.46.6％ of spouses of the females or with fixed partners were HIV positive.Through estimating the time of infection and the time interval between infection and diagnosis,we found that the proportion was 15.5％,from infection to diagnosis as 3 years among the 50 and older age groups,but the proportion of 8 years from infection to diagnosis was 43.6％.We estimated that 66.5％ of the new HIV cases who were at age 50 and over,were infected when they were at that age span.The average time from infection and being tested was (6.8 ± 2.7) years.Conclusion The increasing number of being diagnosed on HIV among the 50-year-olds population might be related to both high risk exposure and belated diagnoses among this population,calling for the necessity of deriving the sources of HIV infection and tailoring the HIV prevention strategies in this population.

Objective To understand the epidemiological characteristics and changing patterns of HIV transmission through heterosexual contact since 2008,and to project the influences of heterosexual transmission mode on the HIV epidemic in China.Methods Demographic data and history of exposure in newly identified HIV/AIDS cases aged 15 years or older,through heterosexual transmission mode from 2008 to 2014,were collected and analyzed.Results The number of HIV/AIDS cases caused by heterosexual transmission increased from 23 402 in 2008,to 68 671 in 2014.The proportion of heterosexual transmission mode increased from 8.7％ in 2008 to 66.4％ in 2014.Among these cases,the proportion of males increased from 55.3％ in 2008 to 68.2％ in 2014.Among those who reported acquiring HIV through heterosexual contact,the proportion of cases through extra-marital sexual acts out of all the newly report ones,increased from 78.2％ in 2008 to 88.2％ in 2014.This mode of infection accounted for 85.2％ in the age 15 to 49 years group,comparing to 84.2％ in the age group of 50 years old or above.The proportion of reported HIV infections through extra-marital sexual acts appeared 93.8％ on males while 69.0％ on females,with statistically significant difference (x2=36 000.000,P＜0.001).Conclusion As the predominant factor of HIV/AIDS epidemic,currently in China,heterosexual transmission showed diversities in different sub-epidemic areas,gender or age groups.Tailored strategies were urgently needed for health education and high-risk behavioral intervention,according to the local epidemic driven factors,respectively.

Objective·To construct a self-healing injectable hyaluronic acid(HA)-based hydrogel(HAPD-Cu)and investigate the effects of different copper ions on the properties of the hydrogel and its vasogenic effiicacy to evaluate its feasibility for clinical wound healing.Methods·Bisphosphonated hyaluronic acid(HAPD)was prepared via a blue-light mediated thiol-ene click reaction between thiolated hyaluronic acid(HASH)and acrylated bisphosphonate(Ac-PD)in the presence of photoinitiator 2959.Then,HAPD was further interacted with Cu2+through metal coordination to prepare HAPD-Cu hydrogels with different Cu2+concentrations,i.e.HAPD-Cu1,HAPD-Cu2,HAPD-Cu3 and HAPD-Cu4.The molecular structures of HASH,Ac-PD,HAPD and HAPD-Cu were verified with 1HNMR and FTIR.Microscopic morphology of HAPD-Cu was observed under SEM.The shear-thinning and self-healing properties of HAPD-Cu were verified by rheometer.The Cu2+release from HAPD-Cu was determined with ICP.Live-dead staining and CCK-8 assay were applied to evaluate the biocompatibility of HAPD-Cu.The in vitro vasculogenic activity of HAPD-Cu was determined by a tubule-forming assay with human umbilical vein vascular endothelial cells and the in vivo vasculogenic activity of HAPD-Cu was assessed by CD31 tissue staining.A rat wound defect model was established in vitro to evaluate its actual repair effect.Results·The preparation of the materials was demonstrated through chemical qualitative and quantitative analytical means.In vitro studies showed that all HAPD-Cu with a loose porous internal structure exhibited outstanding self-healing,injectability and degradability,with a one-week degradation cycle and abrupt release behavior,which can meet the needs of wound healing cycle.All HAPD-Cu showed good biocompatibility except HAPD-Cu4,due to its high Cu2+concentrations.Moreover,its angiogenic effect in vitro or in vivo was enhanced with increasing Cu2+concentrations within the permissible Cu2+concentration range.In vitro wound model experiments also showed that the HAPD-Cu hydrogel significantly promoted wound healing compared with the control group.Conclusion·HAPD-Cu hydrogel constructed via the metal coordination shows excellent shape plasticity,allowing the filling of defective sites in a minimally invasive form,and the release of Cu2+greatly facilitates the establishment of early vascular networks,with giant potential for use in the repair of clinically irregular wounds.