BACKGROUND:At present,postoperative timing or subjective criteria by clinicians are commonly employed to determine the return-to-sport timing for patients undergoing anterior cruciate ligament reconstruction.Unfortunately,these criteria do not adequately consider the biomechanical deficits in patients following anterior cruciate ligament reconstruction. OBJECTIVE:To explore the lower extremity kinematic and kinetic characteristics of athletes after anterior cruciate ligament reconstruction during bilateral vertical jumping. METHODS:Twenty athletes undergoing anterior cruciate ligament reconstruction and twenty healthy athletes,aged 20-24 years,were recruited in Wuhan Sports University from December 2021 to December 2022.All the 40 subjects underwent a bilateral vertical jumping test.The kinematic and dynamic characteristics of the lower limbs at propulsion phase,initial landing time and peak vertical ground reaction force moment. RESULTS AND CONCLUSION:At the initial landing time,the athletes undergoing anterior cruciate ligament reconstruction showed higher hip flexion angle(P=0.031)and lower ankle plantar flexion angle(P=0.018)on the operated side compared with the healthy athletes.At the peak vertical ground reaction force moment,the athletes undergoing anterior cruciate ligament reconstruction had higher hip flexion angle(P=0.016),lower hip abduction angle(P=0.019),lower knee flexion angle(P=0.025),higher knee external rotation angle(P=0.030),and higher ankle external rotation angle(P=0.042)on the operated side compared with the healthy athletes.At the peak vertical ground reaction force moment,the athletes undergoing anterior cruciate ligament reconstruction showed lower knee extension moment(P=0.036),lower knee internal rotation moment(P=0.016),lower hip abduction moment(P=0.004),higher hip extension moment(P=0.040),and higher hip external rotation moment(P=0.005)on the operated side compared with the healthy athletes.To conclude,the athletes undergoing anterior cruciate ligament reconstruction exhibit a stiff landing pattern,in which the knee load on the operated side tends to shift to the hip joint,and show inadequate control of lower limb rotational stability.Therefore,detection and correction of abnormal biomechanical characteristics should be part of the rehabilitation after anterior cruciate ligament reconstruction.

Objective To study the chemical constituents from the herbs of Dendrobium crepidatum and identify its antitumor bioactive compounds.Methods The constituents were extracted by methyl alcohol and isolated by CC and Sephadex LH-20.Their structures were identified by spectroscopic analysis(1H NMR,13CNMR and EIMS).The antitumor activity of the constituents was determined by MTT assay in vitro.Results 9 compouds were obtained and identified as p-hydroxybenzaldehyde(1),p-methoxyphenol(2),p-Hydroxybenzyl alcohol(3),hydroquinone(4),(24R)-ethylcholest-5-en-3-ol-7-one(5),sinalexin(6),bis(2-ethylhexyl)benzene-1,2-dicarboxylate(7),pinoresinol(8),Chaenomin B(9).The antitumor activity of compounds 5～9 was tested,and it was found that compound 9 had good inhibitory activity against A549 cell line.Conclusion Compounds 2～5,7～8 were isolated from the herbs for the first time and compounds 6,9 were isolated from this genus for the first time.IC50 of 9 on A549 cell line is 29.35 μM.

Objective:To explore the application value of CT pulmonary function imaging in patients with Coronavirus Disease 2019 (COVID-19) in the convalescent phase.Methods:The COVID-19 patients who were clinically cured and discharged from Union Hospital, Tongji Medical College, Huazhong University of Science and Technology were prospectively collected from January to April 2020. Clinical pulmonary function tests (PFTs) and CT pulmonary function imaging were performed 3 months after discharge. The Philips IntelliSpace Portal image post-processing workstation was used to obtain the paired inspiratory-expiratory CT quantitative indexes of the whole lung, left lung, right lung and five lobes. The patients were divided into two groups according to whether residual lesions remain in inspiratory CT images: non-residual lesion group and residual lesion group. The chi-square test was used to compare the differences in the PFT results between groups; the Mann-Whitney U test was used to compare the differences in PFT indexes [forced expiratory volume in the first second as percentage of predicted value (FEV 1%), FEV 1/forced vital capacity (FEV 1/FVC), total lung capacity as percentage of predicted value (TLC%), FVC%] and the differences in quantitative CT indexes [lung volume (LV), mean lung density (MLD), volume change in inspiratory phase and expiratory phase (?LV)] between groups. Multiple linear regression was used to analyze the relationship between CT pulmonary function imaging and PFT indexes of convalescent COVID-19 patients. Results:Of the 90 patients with COVID-19, 35 were males and 55 were females; 45 were included in the non-residual lesion group and 45 were included in the residual lesion group. Fifty-three patients had clinical pulmonary dysfunction 3 months after discharge, including 22 patients in the non-residual lesion group and 31 patients in the residual lesion group. In patients with residual disease, left lower lobe and right lower lobe LV, left lower lobe and right lower lobe ?LV in the inspiratory and expiratory phase were smaller than those without residual disease; whole lung, left lung, right lung, left upper lobe, left lower lobe and right lower lobe MLD in the inspiratory phase and left lower lobe and right lower lobe MLD in the expiratory phase were greater than those without residual disease ( P<0.05). Since there was no significant difference in FEV 1/FVC and FVC% between residual and non-residual lesion groups ( P>0.05), FEV 1/FVC and FVC% of two groups were combined. Multiple linear regression analysis showed FEV 1/FVC=91.765-0.016×LV in-right middle lobe+0.014×MLD ex-left lower lobe ( R2=0.200, P<0.001), FVC%=-184.122-0.358×MLD in-right lung-0.024×?LV left upper lobe ( R2=0.261, P<0.001). There was significant difference in TLC% between residual and non-residual lesion groups ( P<0.05), so multiple linear regression analysis was performed both in the two groups. In the non-residual lesion group, TLC%=80.645+0.031×LV ex-right lower lobe ( R2=0.132, P<0.001); In the residual lesion group, TLC%=-110.237-0.163×MLD in-right upper lobe-0.098×MLD ex-left upper lobe -0.025×LV ex-right lower lobe ( R2=0.473, P<0.001). Conclusion:CT pulmonary function imaging can quantitatively analyze the whole lung, unilateral lung and lobulated lung, thus reflecting the regional pulmonary function, providing more valuable diagnostic information for the assessment of pulmonary function in convalescent patients with COVID-19.

Objective To investigate the effect of piR-9994 on the biological behavior of gastric cancer cells and its possible mechanism. Methods The expression of piR-9994 in gastric cancer cell lines (MGC803 and AGS) and normal gastric epithelial cells (GES-1) were detected by qRT-PCR. MGC803 cell line with piR-9994 overexpression and knockdown were constructed. The effects of piR-9994 expression changes on cell proliferation were detected by MTT and clone formation assay. The scratch wound healing assay and Transwell invasion assay were used to detect cell migration and invasion abilities. qRT-PCR and Western blot were used to detect cell proliferation and EMT-related genes expression. Results The expression level of piR-9994 in MGC803 cells was significantly higher than that in normal gastric epithelial cell line GES-1 (P < 0.05). The overexpression of piR-9994 promoted the proliferation, invasion and metastasis of gastric cancer cells, while piR-9994 knockdown had the opposite effect. piR-9994 expression was closely related to cell cycle, especially in S phase. The overexpression of piR-9994 promoted the expression of proliferation-related genes PCNA, CCND1 and Bcl-2, inhibited the expression of apoptosis gene C-PARP, and promoted the expression of EMT-related genes N-cadherin, MMP7, Twist and Vimentin; while piR-9994 knockdown had the opposite effect. Conclusion Abnormal expression of piR-9994 affects the proliferation, invasion, metastasis and EMT process of gastric cancer cells. piR-9994 may be a new biomarker and therapeutic target for gastric cancer.

Objective To explore the expression of circ_0006692 in NSCLC and its relation with clinicopathological characteristics and related mechanism. Methods We collected 50 pairs of NSCLC tissues and adjacent tissues. The expression of circ_0006692 was detected by qRT-PCR and its relation with clinicopathological features was analyzed. We constructed lung cancer A549 cell line with circ_0006692 overexpression and knockdown. Cell proliferation, migration and invasion were detected by MTS, colony forming, wound healing and Transwell invasion assays. qRT-PCR and Western blot were used to detect the effect of circ_0006692 expression change on EMT-related gene expression. Results The expression of circ_0006692 in NSCLC was significantly higher than that in adjacent tissues (P < 0.05). The expression level of circ_0006692 was closely related to tumor size, TNM stage and pulmonary membrane invasion (P < 0.05). circ_0006692 knockdown inhibited cell proliferation, invasion and metastasis, while its overexpression promoted cell proliferation, invasion and metastasis. circ_0006692 knockdown inhibited the expression of EMT-related genes CDH2 and MMP7 in A549 cells and promoted the expression of CDH1. Conclusion The upregulated expression of circ_0006692 in NSCLC is closely related to tumor size, TNM stage and pulmonary membrane invasion. circ_0006692 expression could regulate the proliferation, invasion, metastasis and EMT progression of lung cancer A549 cells.

Objective:To investigate the etiology of necrotizing pneumonia (NP) in children and the clinical characteristics of NP caused by different pathogens in China.Methods:A retrospective, case-control study was performed in children with NP who were admitted to 13 hospitals in China from January 2008 to December 2019. The demographic and clinical information, laboratory data, etiological and radiological findings were analyzed. The data were divided into three groups based on the following years: 2008-2011, 2012-2015 and 2016-2019, and the distribution characteristics of the pathogens in different period were compared. Meanwhile, the pathogens of pediatric NP in the southern and northern China were compared. And the clinical characteristics of the Mycoplasma pneumoniae (MP) NP and the bacterial NP were also compared. T-test or Mann-Whitney nonparametric test was used for comparison of numerical variables, and χ 2 test was used for categorical variables. Results:A total of 494 children with NP were enrolled, the median ages were 4.7 (0.1-15.3) years, including 272 boys and 222 girls. Among these patients, pathogens were identified in 347 cases and the pathogen was unclear in the remaining 147 cases. The main pathogens were MP (238 cases), Streptococcus pneumoniae (SP) (61 cases), Staphylococcus aureus (SA) (51 cases), Pseudomonas aeruginosa (13 cases), Haemophilus influenzae (10 cases), adenovirus (10 cases), and influenza virus A (7 cases), respectively. MP was the most common pathogen in all three periods and the proportion increased yearly. The proportion of MP in 2016-2019 was significantly higher than that in 2012-2015 (52.1% (197/378) vs. 36.8% (32/87), χ 2= 6.654, P=0.010), while there was no significant difference in the proportion of MP in 2012-2015 and that in 2008-2011 (36.8% (32/87) vs. 31.0% (9/29), χ2=0.314, P=0.575).Regarding the regional distribution, 342 cases were in the southern China and 152 in the northern China. Also, MP was the most common pathogen in both regions, but the proportion of MP was higher and the proportion of SP was lower in the north than those in the south (60.5% (92/152) vs. 42.7% (146/342), χ 2=13.409, P<0.010; 7.9% (12/152) vs. 14.3% (49/342), χ 2= 4.023, P=0.045). Comparing the clinical characteristics of different pathogens, we found that fever and cough were the common symptoms in both single MP and single bacterial groups, but chest pain was more common (17.0% (34/200) vs. 6.1% (6/98), χ 2=6.697, P=0.010) while shortness of breath and wheezing were less common in MP group (16.0% (32/200) vs. 60.2% (59/98), χ 2=60.688, P<0.01; 4.5% (9/200) vs. 21.4% (21/98), χ 2=20.819, P<0.01, respectively). The white blood cell count, C-reactive protein and procalcitonin in the bacterial group were significantly higher than those in the MP group (14.7 (1.0-67.1)×10 9/L vs. 10.5 (2.5-32.2)×10 9/L, 122.5 (0.5-277.3) mg/L vs. 51.4 (0.5-200.0) g/L, 2.13 (0.05-100.00) μg/L vs. 0.24 (0.01-18.85) μg/L, Z=-3.719, -5.901 and -7.765, all P<0.01). Conclusions:The prevalence of pediatric NP in China shows an increasing trend during the past years. MP, SP and SA are the main pathogens of NP, and the most common clinical symptoms are fever and cough. The WBC count, C-reactive protein and procalcitonin in bacterial NP are significantly higher than those caused by MP.

Objective:To investigate the normal range of exhaled nitric oxide in healthy children aged 6-18 in Jinan.Methods:The healthy school children aged 6-18 in Jinan from October 11 to 26, 2017 were selected for questionnaire survey, physical examination and exhaled nitric oxide test.The levels of mouth exhaled nitric oxide at the flow rate of 50 mL/s (FeNO 50) and mouth exhaled nitric oxide at the flow rate of 200 mL/s(FeNO 200), alveolar nitric oxide (CaNO), and nasal exhaled nitric oxide at the flow rate of 10 mL/s(FnNO 10) were measured by the electroche-mical method.The distributions of FeNO 50, FeNO 200, CaNO and FnNO 10 were analyzed, and their correlations with gender, age, height and body mass index (BMI) were discussed by the multiple linear regression model. Results:A total of 772 healthy children were enrolled in this study, including 364 males and 408 females, with a median age of 12.1(11.8-12.3) years old, a median height of 154.8(153.6-156.0) cm, and a median BMI of 20.3 (20.0-20.6) kg/m 2. The measured values of FeNO 50, FeNO 200, CaNO and FnNO 10 fluctuated in the range of 3.0-168.0 ppb, 2.0-44.0 ppb, 0.5-44.2 ppb and 0-1 253.0 ppb, respectively.FeNO 50, FeNO 200 and CaNO values showed skewed a distribution, and their 95% upper limits were 35.0 ppb, 13.3 ppb and 8.5 ppb, respectively.The geometric mean(95% CI) of FeNO 50 in males (95% CI)[14.6 (13.7-15.5) ppb] was significantly higher than that in females [13.3(12.7-14.0) ppb], and the difference was statistically significant ( Z=1.470, P=0.027). The multiple linear regression results suggested that, FeNO 50 was positively correlated with age and height ( β=0.023, 0.007, respectively, all P<0.05), and negatively correlated with BMI ( β=-0.016, P<0.05). The geometric mean (95% CI) of FeNO 200in males[7.1 (6.8-7.4) ppb] was significantly higher than that in females[6.4 (6.1-6.6) ppb], and the difference was statistically significant( Z=1.747, P=0.004). The multiple linear regression results suggested that, FeNO 200 was positively correlated with height ( β=0.005) and negatively correlated with gender(female β=-1.126) (all P<0.05). There was no significant difference between male and female in CaNO, which had no correlation with gender, age, height and BMI (all P>0.05). FnNO 10 showed a normal distribution, with a mean value of 456.2 ppb, 95% CI of 29.3-863.4 ppb.The geometric mean (95% CI) of FnNO 10 in males [408.7 (377.1-443.0) ppb] was significantly higher than that in females [368.8 (339.0-401.3) ppb], and the difference was statistically significant ( Z=1.722, P=0.005). The multiple linear regression results indicated that FnNO 10 was related to gender ( β=-36.098, P<0.05), and not correlated with age, height and BMI (all P>0.05). Conclusions:The normal ranges of FeNO 50, FeNO 200, CaNO and FnNO 10 in healthy children aged 6-18 in Jinan are 3.0-35.0 ppb, 2.0-13.3 ppb, 0.5~8.5 ppb and 29.3-863.4 ppb, respectively.FeNO 50 is correlated with age, height and BMI.FeNO 200 is correlated with gender and height.CaNO and FnNO 10 are not correlated with age, height or BMI.

Objective To synthesize a dual-function nanodrug with immunosuppression of tacrolimus (FK506) and lubrication of artificial tear carboxymethylcellulose sodium (CMC), and provide a basis for the clinical treatment of dry eye syndrome. Methods The FK506 nanocrystals were prepared by ultrasonic method, and polyallylamine hydrochloride (PAH) and CMC were deposited alternatively on the surface of FK506 nanocrystals using layer-by-layer (LbL) self-assembly technology to prepare the bifunctional nanodrug. The morphology, particle size, surface charge, and composition of the nanodrug were analyzed. Results The particle size of FK506 nanocrystals was uniform, and the FK506-(PAH/CMC)3 was approximately spherical with uneven surface. Zeta potential detection results showed that the charge changed alternatively with the increasing of layer number. The results of laser scanning confocal imaging and infrared spectroscopy showed that PAH and CMC were successfully modified on the surface of FK506 nanocrystals. Conclusion The prepared FK506-(PAH/CMC)3 nanodrug is expected to provide a scientific basis for the combined treatment of dry eye.

Objective To investigate the effect of lower thoracic epidural block on intestinal epithelial cell apoptosis during hemorrhagic shock and resuscitation in rats.Methods Sixty-four male SD rats placed with lower thoracic epidural catheter were randomly divided into four groups (n=1 6 each):group Sham (sham operation),group HSR (hemorrhagic shock and resuscitation),group NS (hemorrhagic shock and resuscitation+epidural saline 100 μl/kg),and group TEA (hemorrhagic shock and resuscitation+epidural 0.075% ropivacaine 100 μl/kg).The hemorrhagic shock was made described by Chaudry.Rats were resuscitated by transfusing shed blood and normal saline 60 min after hemorrhagic shock.Malondialdehyde (MDA)content,superoxide dismutase (SOD)activity, and protein expression of Bax and Bcl-2 in intestinal epithelium were detected,and epithelial apoptosis index was calculated at 2 h after resuscitation.Results Compared with group Sham,intestinal epithe-lial MDA,Bax expression and epithelial apoptosis were significantly increased,while SOD activity were markedly decreased in groups HSR,NS and TEA (P<0.05).Compared with groups HSR and NS,intestinal epithelial MDA,Bax expression and epithelial apoptosis were significantly decreased, while SOD activity and Bcl-2 expression were markedly increased in group TEA (P <0.05 ). Conclusion Lower thoracic epidural block can enhance the antioxidant and anti-apoptotic ability,and inhibit the oxidative stress and cell apoptosis of intestinal epithelium.Therefore,it can promote the survival rate after hemorrhagic shock and resuscitation through protecting intestinal barrier.

Objective To understand the homology of sequence type 562 (ST562) strains of Burkholderia pseudomallei which circulated in two separate continents (Asia and Australia) at different times.Methods Spe Ⅰ restriction fragments and 4-locus multiple locus variable number tandem repeat analysis (MLVA-4) profiles were extracted from MSHR5858 (ST562 Australia strain) and 350105 (ST562 historical strain of Hainan) genomes respectively by in silico analysis and then compared with the PFGE and MLVA-4 results of five ST562 clinical isolates from Hainan to test their homology.Synteny and homology between MSHR5858 and 350105 genomes were evaluated with bioinformatics methods.Results Five ST562 clinical strains from Hainan shared same PFGE pattern (similarity ＞97％) and this pattern coincided to the map of Spe Ⅰ restriction fragments of Australian strain MSHR5858.The amounts of genomic restriction fragments (Spe Ⅰ) for MSHR5858 and 350105 were 31 and 34 respectively,with 31 of them matched by each other.Five ST562 clinical strains of Hainan were distinct by MLVA-4 profiles,among which HPPH43 (MLVA-4 profile:10,8,10,8) was close to Australia strain MSHR5858 (10,8,8,6),containing identical repeat numbers at VNTR loci 2341k and 1788k;while HK003 (11,8,15,7) and HK061 (11,8,17,7) similar to Hainan historical strain 350105 (11,8,11,8),with same repeat numbers at loci 2341k and 1788k also.High-degree synteny and consistency on genomic contents were observed between 350105 and MSHR5858,indicating a similar origin for the 2 strains.Conclusion All inter-continental and historical ST562 strains ofB.pseudomallei had similar genomic characteristics,supporting the assumption that they had a common origin.Also,it is possible that Hainan historical strain 350105 is the ancestor of all circulating ST562 strains.