BACKGROUND:The treatment of distal tibial fractures with soft tissue injury has always been challenging,and the new retrograde tibial nailing is a new choice.Up to now,there were few reports on the biomechanical properties between the new retrograde tibial nailing,anterograde intramedullary nailing and supercutaneous locking plate. OBJECTIVE:To explore the biomechanical stability of new retrograde tibial nailing,antegrade intramedullary nailing and supercutaneous locking plate in the treatment of distal tibial fractures with soft tissue injury using finite element analysis so as to offer a scientific foundation for clinical application. METHODS:The finite element model of transverse distal tibia fracture was established by relevant software utilizing the CT data of the tibia from a 42-year-old healthy male.Retrograde tibial nailing,antegrade intramedullary nailing and supercutaneous locking plate finite element models were assembled under the principle of fracture fixation.Finally,meshing,applying loads,and data processing were accomplished with the ANSYS 2019 software.Moreover,the stress distribution and displacement of the tibia and internal fixation of each model were compared. RESULTS AND CONCLUSION:(1)The displacement of fracture end in the three groups increased with the increase of load.In all mode loads,the average displacement of the fracture end was the least in the retrograde tibial nailing group,followed by the supercutaneous locking plate group,and the highest in the antegrade intramedullary nailing group.At 800 N vertical load,the displacement difference of the fracture end was statistically significant(P<0.05).There was no statistical significance in other load modes.(2)Under different loads,the tibial stress in the three groups was the highest in the middle of the tibia,and gradually decreased to the proximal and distal ends.The stress distribution of the tibial shaft was the highest in the retrograde tibial nailing group,followed by the supercutaneous locking plate group,and the least in the antegrade intramedullary nailing group.(3)Under different loads,the stress of the tibial stress raiser in the three groups was significantly higher in the supercutaneous locking plate group than in the other two groups,with statistical significance(P<0.05).(4)Under different loads,the stress of the fixators in the three groups was the largest in the supercutaneous locking plate group,followed by the retrograde tibial nailing group,and the minimum in the antegrade intramedullary nailing group.There were significant differences in the stress of fixator stress raiser among the three groups under different loading modes(P<0.05).(5)It is indicated that all three fixation methods have the good anti-rotation ability and axial stability.Retrograde tibial nail shows better biomechanical stability.

BACKGROUND:The treatment of distal tibial comminuted fractures with soft tissue injury has always been challenging.The new retrograde tibial nailing and supercutaneous locking plate are important treatment methods,but their strain and stress shielding at the fracture end during different periods of fracture healing and different load conditions have not been reported. OBJECTIVE:To explore the biomechanical stability of retrograde tibial nailing and supercutaneous locking plate in different periods of fracture healing by finite element analysis to offer a scientific foundation for clinical application and rehabilitation exercise. METHODS:The finite element model of distal tibial comminuted fracture was established by utilizing the CT data of the tibia from a 40-year-old healthy male.Retrograde tibial nailing,supercutaneous locking plate,and callus models were assembled in accordance with the principle of fracture fixation.The finite element analysis was performed using ANSYS software to compare the displacement of the fracture end,the stress shielding of the tibia,the stress of the callus,and the stress distribution of the tibia and the fixation device during different periods of fracture healing. RESULTS AND CONCLUSION:(1)The relative displacement of the tibial fracture decreased gradually with the healing of the fracture,and the displacement decreased significantly after 3 months.At 0 and 1 months after operation,the vertical displacement and total displacement of the supercutaneous locking plate group were higher than those in the retrograde intramedullary nail group.The Z-axis displacement(horizontal medial and lateral displacement)of the two fixation methods was more obvious than the X-axis and Y-axis,and the Z-axis displacement of supercutaneous locking plate group was the most obvious.The maximum Z-axis displacement of the two fixation methods was located on the outside of the tibia,and the minimum displacement was located on the inside of the tibia.(2)The stress shielding rate at different periods of fracture healing gradually decreased with time.The stress shielding rate of the retrograde intramedullary nail was higher than that of the supercutaneous locking plate at different stages of fracture healing.After 3 months,the stress shielding rate of the supercutaneous locking plate was reduced to about 4%,and the stress shielding rate of the retrograde intramedullary nail was reduced to about 40%.(3)The stress of the stress concentration site of the callus in the two fixation methods increased with the increase of the load,and the stress of the callus in the supercutaneous locking plate group was always greater than that in the retrograde intramedullary nail group.The maximum stress distribution of the callus was approximately equally distributed among the two modes of fixation,both in the lateral portion of the tibia.(4)As the fracture healed,the maximum stress of the tibia in the two groups decreased gradually,and the stress in the supercutaneous locking plate group was always greater than that in the retrograde intramedullary nail group.The average stress of the maximum stress area of the tibia in the supercutaneous locking plate group under 1 500 N load was 285 MPa,while that in the retrograde intramedullary nail group was 26 MPa.(5)As the fracture healed,the stress of the fixation device in the two groups decreased gradually,and the stress in the supercutaneous locking plate group was significantly higher than that in the retrograde intramedullary nail group.After 3 months,the stress of the two fixation devices decreased significantly.(6)It is indicated that in the early stage of fracture healing,the strain on the fracture end in the retrograde intramedullary nail group is small,and the maximum stress of the tibia is moderate,allowing early loaded.The fractured ends in the supercutaneous locking plate group had too large strain and too large maximum stress of the tibia,which needed to be partially loaded under protection and could not be fully loaded.In the middle and late stages of fracture healing,the tibial retrograde intramedullary nail and the supercutaneous locking plate could be completely loaded,and the stress shielding rate of the supercutaneous locking plate was significantly lower than the tibial retrograde intramedullary nail.

As interstitial collagen,type Ⅲ collagen(Col Ⅲ)does not express in normal glomeruli.However,in Col Ⅲ nephropathy,a large amount of Col Ⅲ deposit in the mesangial and subendothelial area of the glomeruli.IgA nephropathy with Col Ⅲ deposition was extremely rare.In this article,we reported two cases of such disease.After treating with immunosuppressive agents or traditional Chinese medicine decoction,the renal function of the two patients remained stable and the urinary protein levels reduced significantly.

Purpose::The reconstruction of Allen's type IV fingertip amputation is a clinical challenge. Our team designed bilateral unequal-sized hallux osteo-onychocutaneous free flaps for the long-term reconstruction of Allen's type IV fingertip amputation and conducted a retrospective study with a 5-year follow-up aims to evaluate the effects of this technique.Methods::A retrospective analysis with a 5-year follow-up including 13 patients with Allen's type IV fingertip amputation who were admitted to our hospital from January 2010 to January 2017 was conducted. The patients were treated with bilateral unequal-sized hallux osteo-onychocutaneous free flaps. The operation time, intraoperative blood loss, and complications were recorded, and the survival rate of the transplanted flaps was calculated. During the 5-year follow-up after operation, the nail growth time was recorded and the finger appearance was observed. At the last follow-up appointment, the length, width, and girth of the reconstructed fingertip and contralateral normal fingertip, range of motion of the reconstructed fingertip and contralateral normal fingertip, Semmes-Weinstein test (for the evaluation of tactile sensation), and two-point discrimination testing results were recorded. SPSS 22.0 software was used for the statistical analysis and the data are presented as mean ± SD.Results::The mean operation time was (5.62 ± 0.51) h, the mean intraoperative blood loss was (34.15 ± 3.13) mL, and the survival rate of the transplanted flaps was 100%. During the 5-year follow-up, the average nail growth time was (10.14 ± 1.98) months and the average bone union time was (3.78 ± 0.91) months. The length, width, and girth of the reconstructed fingertip were (31.52 ± 3.73) mm, (17.82 ± 1.74) mm, and (59.75 ± 3.04) mm, respectively, which did not differ from those of the contralateral normal fingertip. The range of motion of the reconstructed fingertip was (12.15 ± 2.79) degrees which is different from that of the contralateral normal fingertip. The average tactile sensation evaluated via the Semmes-Weinstein test and the average two-point discrimination test of the reconstructed fingertip were (0.39 ± 0.17) g and (7.46 ± 1.14) mm, respectively, which were not different from those of the contralateral normal fingertip. The average Maryland score of feet in the donor area was 87.66 ± 7.39, which was satisfactory.Conclusion::Bilateral unequal-sized hallux osteo-onychocutaneous free flaps are an effective method to reconstruct Allen's type IV fingertip amputations with a satisfactory appearance and good sensory function.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To investigate the differences in visual perception between children with autism spectrum disorder(ASD)and typically developing(TD)children when watching different intention videos,and to explore the feasibility of machine learning algorithms in objectively distinguishing between ASD children and TD children.Methods A total of 58 children with ASD and 50 TD children were enrolled and were asked to watch the videos containing joint intention and non-joint intention,and the gaze duration and frequency in different areas of interest were used as original indicators to construct classifier-based models.The models were evaluated in terms of the indicators such as accuracy,sensitivity,and specificity.Results When using eight common classifiers,including support vector machine,linear discriminant analysis,decision tree,random forest,and K-nearest neighbors(with K values of 1,3,5,and 7),based on the original feature indicators,the highest classification accuracy achieved was 81.90% .A feature reconstruction approach with a decision tree classifier was used to further improve the accuracy of classification,and then the model showed the accuracy of 91.43% ,the specificity of 89.80% ,and the sensitivity of 92.86% ,with an area under the receiver operating characteristic curve of 0.909(P<0.001).Conclusions The machine learning model based on eye-tracking data can accurately distinguish ASD children from TD children,which provides a scientific basis for developing rapid and objective ASD screening tools.[Chinese Journal of Contemporary Pediatrics,2024,26(2):151-157]

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.

COVID-19 has been prevalent for three years. The virulence of SARS-CoV-2 is weaken as it mutates continuously. However, elderly patients, especially those with underlying diseases, are still at high risk of developing severe infections. With the continuous study of the molecular structure and pathogenic mechanism of SARS-CoV-2, antiviral drugs for COVID-19 have been successively marketed, and these anti-SARS-CoV-2 drugs can effectively reduce the severe rate and mortality of elderly patients. This article reviews the mechanism, clinical medication regimens, drug interactions and adverse reactions of five small molecule antiviral drugs currently approved for marketing in China, so as to provide advice for the clinical rational use of anti-SARS-CoV-2 in the elderly.

Background: Cervical cancer is still present a major public health problem, especially in developing countries. In International Federation of Gynaecology and Obstetrics 2018, allowing assessment of retroperitoneal lymph nodes by imaging and/or pathological findings and, if deemed metastatic, the case is designated as stage IIIC (with r and p notations). Patients with lymph node metastases have lower overall survival (OS), progression free survival (PFS), and survival after recurrence, especially those who have unresectable macroscopical positive lymph nodes. Retrospective analysis suggests that there may be a benefit to debulking macroscopic nodes that would be otherwise difficult to sterilize with standard doses of radiation therapy. However, there are no prospective study reporting that resecting macroscopic nodes before concurrent chemoradiation therapy (CCRT) would improve PFS or OS of cervical cancer and no guidelines for surgical resection of bulky lymph nodes. The CQGOG0103 study is a prospective, multicenter and randomized controlled trial (RCT) evaluating lymph node dissection on stage IIICr of cervical cancer. Methods Eligible patients are histologically confirmed cervical squamous cell carcinoma, adenocarcinoma, adeno-squamous cell carcinoma. Stage IIICr (confirmed by computed tomography [CT]/magnetic resonance imaging/positron emission tomography/CT) and the short diameter of image-positive lymph node ≥15 mm. 452 patients will be equally randomized to receive either CCRT (pelvic external-beam radiotherapy [EBRT]/extended-field EBRT + cisplatin [40 mg/m2] or carboplatin [the area under curve=2] every week for 5 cycles + brachytherapy) or open/minimally invasive pelvic and para-aortic lymph node dissection followed by CCRT. Randomization is stratified by status of para-aortic lymph node. The primary endpoint is PFS. Secondary endpoints are OS and surgical complications. A total of 452 patients will be enrolled from multiple hospitals in China within 4 years and followed up for 5 years.

Objective To analyze the effect of immune function on the condition and prognosis of asthma in children with asthma. Methods A total of 148 children with asthma diagnosed in Qinghai women and children's Hospital from January 2018 to January 2021 were included in the analysis, the immune function of the children was determined, and the information of all children was followed up for 6 months after treatment; compared The condition and follow-up prognosis of children with immunocompromised and normal immune function were analyzed and discussed, and the correlation between the expression levels of immunoglobulins (IgG, IgA, IgM) and the condition and short-term recurrence prognosis (6 months) of children was analyzed and discussed, so as to guide Prevention and clinical work. Statistical analysis was done using SPSS19.0. Results The average age of 148 children with recurrent respiratory tract infection in the study was (8.94±3.65) years old, including 70 male children. The condition of the children was evaluated and classified into mild/severe cases: 148 children in this study included mild cases. There were 98 cases and 50 severe cases. There were more males and lower BMI levels in severe children (P<0.05) . The levels of IgG, IgA and IgM in children were all lower in severe children (P<0.05) . The follow-up found that the proportion of relapses in critically ill children was higher (P<0.05). Comparing the levels of IgG, IgA, and IgM in mild and severe children, the average levels of IgG, IgA, and IgM in severe children were lower than those in the mild group, and the difference was statistically significant (P<0.05); recurrence within 6 months of follow-up Prognostic evaluation showed that 19 of the 148 children had relapse, and the levels of IgG, IgA, and IgM in severe relapsed children were significantly lower than those without relapse (P<0.05). Analysis of the relevant factors potentially affecting the prognosis of recurrence showed that gender (female) (OR=1.726) , BMI level (weight loss) (OR=1.613) , IgG expression level factor (low expression) (OR=1.898) , IgA expression Level factor (low expression) (OR=3.509) , IgM expression level factor (low expression) (OR=3.217) and disease factor (severe) (OR=3.619) were potential risk factors, which would increase the risk of poor prognosis. Conclusion The asthma attack in children with immunocompromised immune function is relatively severe, and the short-term recurrence probability is higher, which deserves clinical attention and preventive intervention.