BACKGROUND:Irreducible femoral neck fracture was difficult to obtain anatomic reduction.As a new type of internal fixation,the femoral neck system is still blank for the treatment of non-anatomical reduced femoral neck fractures. OBJECTIVE:To explore the biomechanical stability of femoral neck system internal fixation under nonanatomical reduction in the treatment of femoral neck fractures based on finite element analysis. METHODS:CT data of the hip joint of a healthy female adult were obtained.Anatomical reduction of femoral neck fracture models with Pauwels angles of 30°,50°,and 70° were established using Mimics 21.0,Geomagic Wrap 2021,and SolidWorks 2020.The fracture proximal ends of the three anatomical reduction models were shifted upward by 2 mm along the fracture line,and three positive buttress models with different Pauwels angles were obtained.In the same way,three negative buttress models were acquired by shifting downward by 2 mm.SolidWorks 2020 was used to make the femoral neck system internal fixation,and the nine femoral neck fracture models were assembled with the femoral neck system.Then Ansys 19.0 was used for finite element analysis.The displacement distribution and maximum displacement,stress distribution and maximum stress of the femur and femoral neck system were recorded under 2100 N stress. RESULTS AND CONCLUSION:(1)When Pauwels angles were 30°,50°,and 70°,the maximum stresses of the femoral neck system appeared to be concentrated at the junction of the sliding hip screw and anti-rotation screw.The maximum femur stresses appeared to be concentrated in the medial cortex of the femur.The maximum displacement was concentrated at the upper of the femoral head and femoral neck system.(2)When Pauwels angles were 30° and 50°,the maximum displacement and maximum stress of the femoral neck system and femur were:negative buttress>anatomical reduction>positive buttress.(3)When Pauwels angle was 70°,the maximum displacement and maximum stress of the femoral neck system were:negative buttress>anatomical reduction>positive buttress;the maximum displacement and maximum stress of the femur were:negative buttress>positive buttress>anatomical reduction.(4)With the increase of Pauwels angle,the biomechanical advantage of the positive buttress was weakening.However,it was better than a negative buttress.When Pauwels angle was 30°,positive buttress was more stable than anatomical reduction.When Pauwels angle was 50°,the biomechanical difference between positive buttress and anatomical reduction became smaller.When Pauwels angle was 70°,the stability of anatomical reduction was slightly better than positive buttress.(5)If it was difficult to achieve anatomical reduction of femoral neck fracture during operation,but the positive buttress had been displaced within 2 mm,the femoral neck system could be used to offer stable mechanical fixation.It is necessary to avoid negative buttress reduction.

Objective To evaluate the bioequivalence of the vardenafil hydrochloride tablets in fasting and fed conditions in healthy Chinese adult subjects with the test and reference formulations.Methods A randomized,open,single-dose,two-preparation,two-sequence,two-period,crossover design was used,and 40 healthy male subjects enrolled in the fasting state and 66 healthy male subjects enrolled in the fed state.The trial was conducted in two cycles,with 20 mg of either the subject formulation or the reference formulation,vardenafil hydrochloride tablets,being administered in each cycle.The drug concentration of vardenafil in plasma was determined by the liquid chromatography-tandem mass spectrometry(LC/MS-MS)method.Pharmacokinetic parameters were calculated using the non-compartment model,and the safety evaluation indexes were statistically analyzed using SAS 9.4 or above version program data statistical software.Results Arithmetic mean values of the main pharmacokinetic parameters of the subject formulation of vardenafil hydrochloride tablets and the reference formulation in the fasting state:Cmaxwere(34.94±18.33)and(36.69±19.45)ng·mL-1;AUC0-t were(74.38±34.11)and(74.25±33.37)ng·mL-1·h;AUC0-∞ were(76.70±34.36)and(76.46±33.84)ng·mL-1·h,respectively.Arithmetic mean values of the main pharmacokinetic parameters of the subject formulation of vardenafil hydrochloride tablets and the reference formulation in the fed state:Cmax were(22.84±12.48)and(21.68±11.12)ng·mL-1;AUC0_twere(70.82±35.88)and(72.71±34.63)ng·mL-1·h;AUC0-∞ were(73.48±36.44)and(75.29±35.12)ng·mL-1·h,respectively.The 90％confidence intervals for the geometric mean ratios of the main pharmacokinetic parameters such as Cmax,AUC0-t and AUC0-∞ of the prototype drug vardenafil in plasma after oral administration of 20 mg of the test and reference formulations of vardenafil tablets to the subjects in fasting and postprandial states fell within the equivalence interval of 80.00％to 125.00％.Conclusion The subject formulation of vardenafil hydrochloride tablets was bioequivalent to the reference formulation in fasting and fed conditions in healthy Chinese subjects.

Objective To investigate the role of squalene epoxidase(SQLE)knockout in anti-tumor effect vial im-proving CD8+T cell infiltration in melanoma tumor microenvironment.Methods Both immunodeficient and immu-nocompetent mice were inoculated with SQLE knockout B16F10 cells to determine the cell-autonomous and non-au-tonomous regulation of malignancy.Antibody blockade,Luminex multiplex assays,and flow cytometry were em-ployed to explore the impact of SQLE gene knockout on the secretion of cytokines/chemokines and immune cell in-filtration.Bioinformatics analysis was conducted to validate the correlation between SQLE expression and immune infiltration as well as clinical prognosis in melanoma patients.Results Compared with immunodeficient mice,SQLE knockout significantly inhibited melanoma proliferation in immunocompetent mice and prolonged their surviv-al.SQLE knockout induced the secretion of cytokines and chemokines from tumor cells,improved CD8+T cell in-filtration in the tumor microenvironment,thereby potentiating anti-tumor immunity.Bioinformatics analysis sugges-ted a significant correlation between SQLE and its corresponding immune infiltration markers with the prognosis of melanoma patients.Conclusion SQLE regulates anti-tumor immunity by controlling cytokines and chemokines re-leasing in tumor microenvironment,thus holding promise as a novel tumor immunotherapy target and efficacy predic-tion molecular indicator.

The ICR(Institute of Cancer Research)mouse infection model was constructed to study the pathogenicity of Sal-monella Telelkebir serotype,and the pathogenic identification of mouse isolates was carried out.Observe the bacterial excretion cycle,evaluate the pathogenicity of Salmonella serotype to mice,and calculate the LD50 by the changes in clinical characteris-tics,histopathology and tissue bacterial load of infected mice;by flight mass spectrometry,biochemical identification,serotype identification,molecular typing and other experiments,compared with human isolates;virulence gene analysis was carried out by PCR experiment and whole genome sequencing.The LD50 of Salmonella Telelkebir is 2.67 × 108 CFU/mL;curling and fluffing may occur 0.5 h after infection;autopsy of dead mice showed that the small intestine was severely congested,with more bubbles and fluid accumulation,cecal necrosis,liver apical degeneration and necrosis,necrotic foci on the surface of the kidney and spleen atrophy;the bacterial load of spleen,kidney,lung,liver and jejunum in mice reached its peak at 3 days after infection,while that of heart at 6 days;the bacterial excretion time of the high-dose group exceeded 100 days;The level of CD3 in tissues increased with increasing dose,with inflammatory cell infiltration,myocardial capillary dilation and hyperemia,large area of vacuoles,degeneration and necrosis of hepatocytes,obvious enlargement of splenic sinus,blurred zoning,thickening of glomerular basement membrane,partial exfoliation of ciliated epithelium,atrophy and exfoliation of jejunal villi;PCR and whole genome sequencing revealed Salmonella-related virulence genes such as cdtB,plt A and pltB.This study was the first to successfully establish the ICR mouse model of Salmonella Telelkebir,demonstrating that this serotype of Salmonella has some pathogenicity.

Objective To investigate the therapeutic effect of transcutaneous auricular vagus nerve stimulation(taVNS)on overweight/obesity patients,and to explore its central mechanism.Methods Twenty-six overweight/obesity patients were randomly divided into two groups,12 cases in the taVNS test group(shortened as the taVNS group)and 14 cases in the lifestyle intervention control group(shortened as the control group).The patients in the control group were treated with online lifestyle intervention of calorie-restricted diet(CRD),and the patients in the taVNS group were treated with taVNS on the basis of the intervention for the control group.The taVNS was performed on unilateral acupoints of spleen and endocrine,twice(in the morning and at evening)per day,for five days a week.The treatment for the two groups covered four weeks.The obesity indicators such as body weight,body mass index(BMI)and waist circumference of the patients in the two groups were observed before and after treatment.Moreover,the resting-state cerebral functional magnetic resonance imaging(fMRI)data of the patients were collected after treatment,and then the regulatory effect of taVNS on the regional homogeneity(ReHo)of local cerebral area of the patients was observed.Results(1)During the trial,one case in each group dropped off,and a total of 24 patients(including 13 cases in the control group and 11 cases in the taVNS group)were finally included in the statistical analysis of the observation indicators.(2)After treatment,the body weight,BMI and waist circumference of patients in the taVNS group were decreased compared with those before treatment(P＜0.05),while the obesity indicators in the control group only showed a downward trend compared with those before treatment,the differences being not statistically significant(P＞0.05).The improvement of the obesity indicators of body weight,BMI,and waist circumference in the taVNS group was significantly superior to that in the control group,and there were statistically significant differences in the post-treatment indicators and in the pre-and post-treatment difference values of the indicators between the two groups(P＜0.05 or P＜0.01).(3)After treatment,the taVNS group had greater ReHo values in the left prefrontal lobe and medial frontal gyrus than the control group,and the control group had greater ReHo value in the right parietal lobe than the taVNS group,which indicated that compared with the control group,the ReHo of the left prefrontal lobe and medial frontal gyrus in the taVNS group was increased and the ReHo of the right parietal lobe was decreased(Pvoxel＜0.001,Pcluster＜0.05,corrected by FWE level).Conclusion As a non-invasive treatment method,taVNS exerts certain efficacy for the treatment of overweight/obesity patients.The central response mechanism for treatment of obesity is probably related with the modulation of taVNS on the functional areas of left prefrontal lobe,medial frontal gyrus,and right parietal lobe of the patients.

Objective To investigate the nutritional status of children with cystic fibrosis(CF)and understand the correlation between malnutrition and clinical characteristics as well as lung function.Methods A retrospective analysis was performed on clinical data of CF children admitted from January 2016 to June 2023.Clinical characteristics of CF children with different nutritional statuses were compared,and the correlation between malnutrition and lung function was analyzed.Results A total of 52 CF children were included,comprising 25 boys(48％)and 27 girls(52％),aged between 7 months and 17 years.Respiratory symptoms were the predominant clinical manifestations(96％,50/52).The prevalence of malnutrition was 65％(34/52),with moderate/severe malnutrition being the most common(65％,22/34).The malnutrition group had a longer duration of illness,higher proportion of digestive system symptoms,and lower levels of serum albumin(P＜0.05).Pulmonary function parameters,including forced expiratory volume in one second as a percentage of the predicted value,ratio of forced expiratory volume in one second to forced vital capacity,forced expiratory flow at 25％of forced vital capacity exhaled,forced expiratory flow at 50％of forced vital capacity exhaled,forced expiratory flow at 75％of forced vital capacity exhaled,and maximum mid-expiratory flow as a percentage of the predicted value,were lower in the malnutrition group compared to the normal nutrition group(P＜0.05).Correlation analysis showed body mass index Z-score was positively correlated with the above six pulmonary function parameters(P＜0.05).Conclusions The prevalence of malnutrition is high in CF children and is associated with decreased lung function.CF children with higher body mass index have better lung function.Therefore,screening and evaluation of nutritional status as well as appropriate nutritional intervention should be emphasized in CF children.[Chinese Journal of Contemporary Pediatrics,2024,26(3):275-281]

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

The epidemiology and etiology of three suspected cases of imported skin diphtheria infection in Fujian Province were investigated.Secretion samples of patients with skin damage were collected for isolation and culture of Corynebacterium diphtheriae.Biochemical identification and mass spectrum analysis of pure cultures of suspected C.diphtheriae were conduc-ted,the virulence-related genes,including diphtheria toxin reporter(dtxR),toxin A(toxA),and toxin B(toxB)were detec-ted,and multilocus sequence typing(MLST)was performed.All three cases had typical clinical manifestations of cutaneous diphtheria,and C.diphtheriae was isolated from the damaged skin.The virulence genes of two C.diphtheriae strains isolated from two cases were identified as dtxR(+),toxA(-),and toxB(-),and the MLST type was ST-703.The virulence genes of C.diphtheriae isolated from one case were identified as dtxR(+),toxA(+),toxB(+),and the MLST type was ST-248.There is an increased risk of diphtheria in Fujian Province.C.diphtheriae without diphtheria toxin genes can also cause skin diphtheria.

Aim To design the pyrimidoindole deriva-tive N-butyl-9H-pyrimido[4,5-b]indole-2-carboxamide(BFPI)and synthesize it to investigate whether it in-hibits macrophage pyroptosis and foaming effects through the NLRP3/Caspase-1 pathway.Methods BFPI was synthesized using 2,4,6-triethoxycarbonyl-l,3,5-triazine and 2-aminoindole as starting materials and structurally characterized by 1H NMR,13C NMR,and ESI-MS.The in vitro cultured mouse monocyte macro-phage cell line RAW264.7 was divided into blank,model(PA)and therapeutic(BFPI)groups,and the cells in each group were treated with the corresponding culture medium for 24 h.The proliferative viability was detected by MTT assay,and the formation of intracel-lular lipid droplets was detected by oil red O staining,and NLRP3 was detected by Western-blot and RT-qPCR,caspase-1 and MCP-1 mRNA and protein ex-pression levels by Western blot and RT-qPCR.Results Compared with the blank group,the proliferation vi-ability of cells in the model group significantly de-creased and the formation of lipid droplets significantly increased;compared with the model group,the prolif-eration viability of cells in the treatment group signifi-cantly increased and the formation of lipid droplets sig-nificantly decreased,and the differences were statisti-cally significant(P＜0.01);compared with the blank group,the cellular NLRP3,caspase-1 and MCP-1 mR-NA and protein expression levels of cells in the model group significantly increased;compared with the model group,the expression levels of the above indexes of the cells in the treatment group significantly decreased,and the difference was statistically significant(P＜0.01).Conclusions BFPI contributes to delaying macrophage-derived foam cell formation during athero-genesis by inhibiting macrophage NLRP3,caspase-1,and MCP-1 expression and thereby promoting their pro-liferation and inhibiting lipid phagocytosis.

Aim To compare the pharmacokinetics of pemirolast potassium tablets in healthy subjects in Chi-na under single fasting and postprandial conditions,and to evaluate the bioequivalence of the test prepara-tion(T)and the reference preparation(R).Methods A randomized,open-ended,single-dose,two-cycle,double-cross bioequivalence trial design was adopted,and 26 and 30 subjects were enrolled in the fasting group and the postprandial group,respectively,and 10 mg of the test preparation and the reference preparation were taken in the fasting or postprandial state each cy-cle,and venous blood was collected at the designed time points before and after the administration cycle.The concentration of pemirolast potassium in plasma was determined by LC-MS/MS method,and the phar-macokinetic parameters were calculated with PhoenixTM WinNonlin ?(8.3)software,and the bioequivalence analysis of the two preparations was performed.Re-sults The t1/2 of the test preparation and the reference preparation was(4.44±0.91)h and(4.49±0.93)h,respectively;the median tmax was(1.96±1.29)h and(2.18±1.25)h,respectively;the Cmax was(867.12±205.56)μg·L-1 and(863.35±172.03)μg·L-1,respectively;the AUC0-t was(5 513.23±1463.67)h·μg·L-1 and(5 661.32±1 628.65)h·μg·L-1,respectively;AUC0_∞ was(5 699.81±1477.68)h·μg·L-1 and(5 849.44±1 644.75)h·μg·L-1,respectively.The statistical results of the 90％confidence intervals of the main pharmacokinetic parameters Cmax,AUC0-t,and AUC0-∞ was 92.49％～107.53％,94.71％～100.67％and 95.28％～100.27％,respectively,all of which were within the range of 80.00％～125.00％,and the safety of the tested preparation and the reference preparation was good when taken orally on an empty stomach.The t1/2 of single oral administration after prandial administra-tion of the tested preparation and the reference prepara-tion was(4.46±0.78)and(4.51±0.84)h,respec-tively;the median tmax was(3.08±1.36)h and(3.28±1.28)h,respectively;the Cmax was(683.83±111.87)μg·L-1 and(689.77±110.24)μg·L-1,respectively;the AUC0-t was(5 695.99±1566.05)h·μg·L-1 and(5 773.60±1 551.04)h·μg·L-1,respectively;the AUC0-∞ was(5 914.06±1 551.86)h·μg·L-1 and(5 967.30±1552.89)h·μg·L-1,respectively.The 90％confi-dence interval of Cmax,AUC0-t,and AUC0-∞ was 93.56％～104.69％,96.43％～100.83％,and 97.29％～101.14％,respectively,which was in the range of 80.00％～125.00％,and the safety of the tested preparation and the reference preparation was good after meals.Conclusion In the state of fasting and postprandial single oral administration,the two kinds of pemirolast potassium tablets have good bio-equivalence.