BACKGROUND: Weightlessness is one of the important reasons to cause lower limb muscle atrophy of the astronauts, which is serious harm to the health of astronauts. OBJECTIVE: To explore the progress of weightlessness that cause lower limb muscle atrophy. METHODS: A computer-based online search of PubMed database and CNKI database was performed to search related articles between May 1981 and March 2013 with the key words of “weightless, weightlessness, muscle, atrophy, space” in English and Chinese, respectively. Literatures related to progress of weightlessness that cause lower limb muscle atrophy were selected; in the same field, the literatures published lately in authoritative journals were preferred. RESULTS AND CONCLUSION: A total of 409 literatures were primarily selected, and 47 documents were involved for summary according to the inclusion criteria. The progress of weightlessness that cause muscle atrophy is the hot topic among the space medical research. The main reasons that cause weightlessness muscular atrophy include the reduced muscle spindle neurotrophic factor synthesis caused by reduced information transmission of peripheral sensory nerve, damage of muscle cel ultrastructure, substantial decline in mitochondrial myofibrils, troponin decreasing, decreased intracel ular calcium content, and decreased antigravity muscle blood flow in lower limbs.

Objective To investigate the three-dimensional morphological characteristics of tibial plateau based on CT image post-processing technique and analyze its significance in preoperative planning of tibial plateau fractures.Methods Multi-slice spiral CT data of 98 humans (56 males and 42 females) with normal tibial plateau and 30 patients (15 males and 15 females) with tibial plateau fractures were extracted.Morphological measurements of the tibial plateau were achieved by means of a three-dimensional measurement method based on points,lines and surfaces.Differences in threedimensional parameters between genders in normal tibial plateau and differences between normal tibial plateau and tibial plateau fractures were analyzed.Results Differences of males and females were significant in width of tibial plateau [(73.2 ± 3.7) mm,(65.5 ± 3.7) mm],anteroposterior dimension of medial tibial plateau [(39.8 ± 3.5) mm,(34.8 ± 2.6) mm] and anteroposterior dimension of lateral tibial plateau [(34.0 ± 3.3) mm,(29.8 ± 3 5) mm] (P ＜ 0.05),but not in varus inclination of tibial plateau [(3.19 ± 1.98) °,(3.16 ± 1.89) °],medial plateau posterior slope [(7.31 ± 3.04) °,(8.16 ± 2.46)°] and lateral plateau posterior slope [(5.23 ±2.35)°,(5.60 ±2.55)°] (P ＞0.05).Above parameters in three-dimensional morphological measurements of tibibial plateau fractures varied compared to the normal reference value (P ＜ 0.05).Intraclass correlation coefficient (ICC) for intra-observe and inter-observer agreement in normal tibial plateau measurement was excellent.Conclusions Present research provides a series of scientific and objective data for preoperative planning of tibial plateau fractures.Measurements of tibial plateau can assist the evaluation of reduction of tibial plateau fractures.

Objective To discuss the curative effect of computer assisted pre-operation plan (CAPP) in treating the geriatric intertrochanteric femoral fracture.Methods The data of intertrochanteric fractures treated with PFNA-Ⅱ between March 2012 and June 2015 were retrospectively analyzed.They were divided into two groups by preoperative design.One group was the CAPP group consisting of 53 patients with a mean age of 75.3 years (range,60-92 years).According to the Evans Classification,there were 12 Evans type Ⅰb,9 Evans type Ⅰc,15 Evans type Ⅰd and 17 Evans type Ⅱ fractures.The other group was the non-CAPP group consisting of 74 patients with a mean age of 76.6 years (range,62-95 years).There were 18 Evans type Ⅰb,15 Evans type Ⅰc,20 Evans type Ⅰd and 21 Evans type Ⅱ fractures.Operation time,intraoperative blood loss,times of fluoroscopy during operation and days of hospital stay were compared.The hip joint function was evaluated by Harris score at the final follow-up.Results The CAPP meanly cost 24.7 min.The consistency of the surgery and CAPP was up to 100％.In the CAPP group,the average operation time was 46.8±6.5 min;the average times of fluoroscopy during operation were 12.0±2.3 times;and the average blood loss was 154.4±27.6 ml.In the non-CAPP group,the average operation time was 57.8±10.3 min;the average times of fluoroscopy during operation was 20.9±3.2;and the average blood loss was 235.0±65.8 ml.All above data in the CAPP group were significantly lower than those in the non-CAPP group.The mean days of hospital stay were 13.9±1.3 days in the CAPP group and 14.3±1.4 days in non-CAPP group.The days of hospital stay had no significant difference between the two groups.Forty-five patients with an average follow-up period of 18.3 months were reviewed in the CAPP group.Fifty patients were followed up with an average period of 19.2 months in the non-CAPP group.At the final follow-up,the average Harris score was 88.6±2.8 points (range,84-96 points) in the CAPP group and 87.5±3.2 points (range,80-95 points) in the non-CAPP group.Conclusion CAPP system is convenient and efficient.It can facilitate the treatment of intertrochanteric fracture effectively.

Objective: To investigate the prevalence and influencing factors of electronic cigarette (e-cigarette) use among adolescents in Haidian District, Beijing, so as to provide insights into tobacco control among adolescents. Methods: The students in junior high school, high school and vocational high school were recruited from Haidian District using the stratified cluster random sampling method in October of 2019, and subjects' demographic features and use of e-cigarettes were collected using the Questionnaire for Survey on Tobacco Prevalence among Adolescents in China in 2019. The factors affecting e-cigarette use were identified among adolescents using the multivariable logistic regression analysis. Results: A total of 658 adolescents were investigated, including 315 junior high school students ( 47.87% ), 221 high school students ( 33.59% ), and 122 vocational high school students ( 18.54% ), and there were 261 boys ( 39.66% ), and 397 girls ( 60.34% ). There were 605 students that had heard of electronic cigarettes ( 91.95% ), 63 students that had used e-cigarettes (9.57%), and 23 students with current use of e-cigarettes ( 3.50% ), and there were 39 students that had never used electronic cigarettes but had a tendency of use in the future ( 6.55% ). Multivariable logistic regression analysis identified parental smoking ( OR=2.408, 95%CI: 1.179-4.916 ), close friends' smoking ( OR=3.597, 95%CI: 1.715-7.544 ) and cigarette smoking ( OR=23.029, 95%CI: 11.092-47.812 ) as factors affecting e-cigarette use among adolescents. Conclusions The prevalence of electronic cigarette uses is 9.57% among adolescents in Haidian District, Beijing. Parental smoking, peer smoking and use of cigarettes may facilitate the use of e-cigarettes among adolescents.

Objective To investigate the value of electronic bronchoscopy in the diagnosis of children respiratory diseases. Methods The electronic bronchoscopy results in 400 children with respiratory disease were retrospectively analyzed. Results In 400 children, there were 246 cases with simple endobronchial inflammation, 67 cases with bronchial malacia, 38 cases with bronchial stenosis, 23 cases with bronchial foreign , 4 cases with tracheal bronchus, 4 cases with epiglottic cyst, 3 cases with bronchiectasis, 3 cases with endobronchial granulation, 3 cases with laryngomalacia, 2 cases with vascular ring compression of the trachea, 2 cases with laryngeal web, 1 case with subglottic cyst, 1 case with subglottic neoplasm, 1 case with tracheoesophageal fistula, 1 case with bronchial atresia (left) and 1 case with trachea cyst. All the children had no serious complications. Conclusions Electronic bronchoscopy can effectively improve the level of diagnosis and treatment of children' s respiratory system disease, and it is worth of clinical promotion.

Objective Long non-coding RNA(lncRNA),with more than 200 nucleotides in length,is closely related to many endocrine and metabolic diseases as a functional RNA.Researches has shown that lncRNA can regulate gene expression in multiple levels,including participation in chromatin imprints,in combination with apparent modified complexes or transcription factors to play a transcriptional regulation,and binding with miRNA,mRNA or protein to play the role of post-transcriptional regulation.The disorder of lncRNA expression and the mutation of the primary sequence or variation of the secondary structure are associated with many human diseases.The study of lncRNA in diabetic kidney disease is still in its infancy.In addition,since some lncRNA can be detected in human body fluid and have good specificity and accessibility,it is speculated that lncRNA can be used as a new potential biomarker for the diagnosis and prognosis of diabetic kidney disease.

OBJECTIVE: To investigate the association of tyrosine hydroxylase (TH) C-824T polymorphism with essential hypertension (EH) susceptibility in Hunan Han population by a case-control study. METHODS: A case-control study was performed on 368 EH patients and 353 healthy controls of Han nationality recruited in Hunan province. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)was used to genotype the C-824T polymorphism. RESULTS: (1) Genotype frequencies for TH-824CC and -824CT+-824TT genotypes were 89.9% and 10.1%, respectively for EH patients and 88.7% and 11.3%, respectively for the controls. No significant difference in the genotype distribution of C-824T polymorphism between the patients and controls was observed (P=0.579). Allele frequencies of TH C-824T also showed no significant difference between the patients and controls (P=0.515). (2) When adjusted by EH risk factors, results of unconditional logistic regression analysis showed that there was no association between TH C-824T polymorphism and EH susceptibility (P=0.264). (3) When stratified by gender, no significant difference in the genotype distribution of TH C-824T polymorphism was observed between the patients and controls in either male or female subjects (P=0.841 and P=0.288). (4) Diastolic blood pressure (DBP) in individuals with -824 CT+TT genotype was significantly higher than that in individuals with -824 CC genotype in the controls (P=0.015). (5) When stratified by gender, significant difference in DBP between TH C-824T CT+TT genotype and CC genotype was observed in the male (P= 0.018) but not in the female (P=0.083) controls. CONCLUSION There is no association between TH gene C-824T polymorphism and EH susceptibility in Hunan Han population. The TH gene C-824T polymorphism is possibly associated with increased DBP in the males in Hunan Han population.
Adult ; Case-Control Studies ; China ; ethnology ; Female ; Genetic Predisposition to Disease ; Genotype ; Humans ; Hypertension ; enzymology ; genetics ; Male ; Middle Aged ; Polymorphism, Genetic ; Sex Factors ; Tyrosine 3-Monooxygenase ; genetics

【Objective】 To establish a model for predicting the risk of urinary incontinence after holmium laser enucleation of the prostate (HoLEP). 【Methods】 The clinical data of 258 patients with benign prostatic hyperplasia (BPH) who underwent HoLEP in our hospital during Jan.2019 and Feb.2022 were retrospectively analyzed. According to the occurrence of urinary incontinence after surgery, they were divided into the urinary incontinence group (n=84) and non-urinary incontinence group (n=174). Lasso regression was used to screen the predictors of urinary incontinence after HoLEP. Logistic regression was used to establish a suitable model, and a nomogram of urinary incontinence after HoLEP was drawn. Bootstrap was used to verify and draw the calibration curve of the model, calculate the C index, and draw the clinical decision curve to further verify the accuracy and identification ability of the model. 【Results】 Predictors including International Prostate Symptom Score (IPSS), Quality of Life Score (QoL), body mass index (BMI), diabetes, prostate volume (PV), and prostate-specific antigen (PSA) were selected, based on which a prediction model was constructed. The area under the receiver operating characteristic (ROC) curve of the prediction model was 0.766 0, and the 95% confidence interval was 0.704-0.828. Bootstrap internal validation showed a C-index of 0.766 2, and the calibration model curve coincided well with the actual model curve. The clinical decision curve analysis showed that the model had high accuracy, and net benefit in the probability of urinary incontinence was within 10% to 82%. 【Conclusion】 IPSS, QoL, diabetes, prostate volume, and PSA are predictors that can affect the occurrence of urinary incontinence after HoLEP. The model has high accuracy, identification ability and net benefit.

Objective To construct the Hut78 cell line with EZH2 gene knocked into by CRISPR/Cas9 system. Methods The EZH2 expression vector pMD-18T-EZH2 with homologous arm and the sgRNA expression vector pSpCas9 (BB)-2A-Puro-sgRNA, which could cut the double stranded genomic DNA, were constructed, and the two vectors were co-transfected into Hut78 cells. Then the expression of EZH2 mRNA was detected by qPCR, and the expressions of EZH2 and H3K27me3 proteins were detected by Western blot assay. Results The pMD-18T-EZH2 and pSpCas9(BB)-2A-Puro-sgRNA recombinant vectors were confirmed by DNA sequencing. When Hut78 cells were transfected with the two recombinant plasmid, qPCR results showed that the expression of EZH2 mRNA was significantly increased, and Western blot analysis showed that the expressions of EZH2 and H3K27me3 proteins were significantly increased. Conclusion EZH2 gene is successfully knocked into Hut78 cells by CRISPR/Cas9 system.

Objective To explore the factors, characteristics and imaging manifestations of ankle joint injury in amateur marathoners (no formal training and no marathon career). Methods From December 2018 to March 2019, the amateur marathon runners in Guangdong Zhuhai had been recruited as research subjects according to the study inclusion and exclusion criteria. The questionnaires were used to collect relevant data, and the subjects underwent MRI scans of the ankle joint. The ankle joint special phased array coils were used to perform fast spin echo sequence (TSE) coronal T1WI and proton density?weighted fat?suppression sequence (PDWI?FS). Axial, coronal and sagittal scans, three?dimensional?double echo steady?state sequence (3D?DESS) and three?dimensional variable flip angle fast spin echo sequence (3D?SPACE) scans were also acquired. The results of the examination were independently analyzed by two radiologists (5 and 17 years of work experience, respectively) on the ligament, tendon, bone marrow and ankle joint injuries. When they had inconsistent views, the diagnosis provided by the third radiologist (27 years of work experience) was considered a final diagnosis. The relationship between ankle injury and different running postures, the number of participating in marathons and training intensity was analyzed, and the independent sample χ2 was used for statistical analysis. The consistency of two radiologists was tested by Kappa test. Results According to the inclusion and exclusion criteria, 39 subjects were included, with 64 ankles totally, 35 right ankles and 29 left ankles. MRI showed that (1) Ligament injuries: 28 ankles were anterior talofibular ligament injuriy;50 ankles were posterior talofibular ligament injury; 60 ankles the calcaneofibular ligament injuries and 54 ankles were deltoid ligament injuries, without complete injury. (2) Tendon sheath effusion and injuries: peritendinous effusion was common, with 47 flexor hallucis longus tenosynovitis, 49 posterior tibialis tenosynovitis, 37 flexor digitorum longus tenosynovitis, 7 peroneus longus tenosynovitis and 5 peroneus brevis tenosynovitis. (3) Synovitis effusion: 43 posterior ankle synovitis and local effusion. (4) Others: cartilage injury in 2 ankles, bone marrow edema in 8 ankles, and among them stress fracture in 2 ankles. The two radiologists had good consistency with the Kappa value of 0.91. Regarding the running posture, the incidence of ligaments injuries was obviously higher in those who landed on the hind foot than in those landed on front and middle foot,and the difference was statistically significant(P=0.013, χ2 value was 6.191).The incidence of tendon injuries was higher in those who landed on the front middle foot than in those landed on the hind foot, and the difference was statistically significant (P=0.029, χ2 value was 4.775). Those with larger training (training running ≥300 km/month) had significant ankle injury (P=0.005, χ2 value was 7.844). Conclusion The MRI features of ankle joint injuries in amateur marathon volunteers are related to different running postures and training intensity.