OBJECTIVE To investigate the relationship of long non-coding RNA （LncRNA） metastasis-associated lung adenocarcinoma transcript 1 （MALAT1） and doxorubicin （DOX） resistance in osteosarcoma （OS） cells. METHODS MG-63 and MG-63/DOX cells were treated with different concentrations of DOX （0， 0.01， 0.05， 0.1， 1 μmol/L）， and survival rates and half maximal inhibitory concentration were determined using CCK-8 assay. The expressions of LncRNA MALAT1 in MG-63 and MG-63/ DOX cells were detected by real-time quantitative fluorescence PCR. MG-63/DOX cells were divided into Control group， knocking down LncRNA MALAT1 negative control （sh-NC） group， sh-MALAT1 group， sh-MALAT1+anti-NC group， and sh-MALAT1+ anti-miR-154-5p group. The expressions of LncRNA MALAT1， miR-154-5p and cyclin D1 （CCND1） mRNA in MG-63/DOX cells of each group were detected. The effects of knocking down LncRNA MALAT1 on the proliferation， migration， invasion， and apoptosis of MG-63/DOX cells were detected by CCK-8 assay， scratch test， Transwell experiment and flow cytometry， respectively. The expression of proliferating cell nuclear protein （PCNA） and CCND1 protein in MG-63/DOX cells was detected by Western blot assay. Interactions between LncRNA MALAT1 and miR-154-5p， miR-154-5p and CCND1 were detected by dual luciferase reporter gene experiment. RESULTS Compared with 0 μmol/L DOX， 0.01， 0.05， 0.1 and 1 μmol/L DOX could reduce the survival rates of MG-63 and MG-63/DOX cells （except for 0.01 μmol/L DOX） （P＜0.05）， IC50 were 0.07 and 0.13 μmol/L， respectively. The survival rate， cell migration number and invasion number of MG-63/DOX cells， scratch closure rate， mRNA expressions of LncRNA MALAT1， mRNA and protein expressions of CCND1， and PCNA protein expression in sh-MALAT1 group were significantly lower than sh-NC group and Control group； the apoptosis rate and miR-154-5p expression were significantly higher than sh-NC group and Control group （P＜0.05）. sh-MALAT1+anti-miR-154-5p group was able to reverse the aforementioned biological effects in sh-MALAT1 group （P＜0.05）. In MG-63/DOX cells transfected with both MALAT1-wild type （WT） and CCND1-WT， the luciferase activity in the miR-154-5p mimic group was significantly lower than mimic negative control group （P＜ 0.05）. CONCLUSIONS Knocking down LncRNA MALAT1 can inhibit the DOX resistance of OS cells， and its mechanism may be targeting the miR-154-5p/CCND1 axis.

Objective:To investigate the clinical significance of prenatal screening and genetic analysis in the diagnosis of fetal aberrant right subclavian artery(ARSA).Methods:The ultrasonographic features of ARSA fetu-ses detected by prenatal ultrasound at the University of Hong Kong-Shenzhen Hospital from October 2017 to March 2022 were retrospectively analyzed.The fetuses were divided into isolated ARSA group and complicated ARSA group.Their genetic analysis results and pregnancy outcome were analyzed.Results:Among 30,260 preg-nant women,185 fetuses were diagnosed with ARSA by prenatal ultrasound screening,with an incidence of 0.6％;5 fetuses(2.6％)were diagnosed by ultrasound in the first trimester,and the remaining were diagnosed by fetal grade Ⅲ structural ultrasound examination at 20～24 weeks' gestation.Among them,158 fetuses(85.4％)had isolated ARSA,and 27(14.6％)had complicated ARSA.Among fetuses with ARSA and other structural abnormal-ities,cardiovascular system accounted for the highest proportion(44.4％),followed by nervous system(22.2％)and urinary system(22.2％).Through genetic analysis,8.3％(4/48)fetuses with isolated ARSA and 40.0％(4/10)fetuses with complicated ARSA were found to have chromosomal numerical or structural abnormalities,with statis-tically significant difference between the two groups(P=0.024).Genetic analysis was completed in 48 isolated ARSA,and the positive rate of pathogenic copy number variants(CNV)was 4.2％(2/48),which was not signifi-cantly different from the pathogenic CNV incidence rate of 0.4％(1/239)in elderly pregnant cases during the same period(P=0.074).The Down syndrome positive likelihood ratio(LR+)for isolated ARSA was 2.5 and the Down syndrome LR+for complicated ARSA was 49.6.Conclusions:Complicated ARSA is often associated with cardiovascular abnormalities and is more likely to develop Down syndrome than isolated ARSA.Although the inci-dence of pCNV in isolated ARSA is slightly higher than the natural incidence,the correlation between pCNV and i-solated ARSA has not been clearly determined by the current sample size.

Objective:To investigate the clinical significance of prenatal screening and genetic analysis in the diagnosis of fetal aberrant right subclavian artery(ARSA).Methods:The ultrasonographic features of ARSA fetu-ses detected by prenatal ultrasound at the University of Hong Kong-Shenzhen Hospital from October 2017 to March 2022 were retrospectively analyzed.The fetuses were divided into isolated ARSA group and complicated ARSA group.Their genetic analysis results and pregnancy outcome were analyzed.Results:Among 30,260 preg-nant women,185 fetuses were diagnosed with ARSA by prenatal ultrasound screening,with an incidence of 0.6％;5 fetuses(2.6％)were diagnosed by ultrasound in the first trimester,and the remaining were diagnosed by fetal grade Ⅲ structural ultrasound examination at 20～24 weeks' gestation.Among them,158 fetuses(85.4％)had isolated ARSA,and 27(14.6％)had complicated ARSA.Among fetuses with ARSA and other structural abnormal-ities,cardiovascular system accounted for the highest proportion(44.4％),followed by nervous system(22.2％)and urinary system(22.2％).Through genetic analysis,8.3％(4/48)fetuses with isolated ARSA and 40.0％(4/10)fetuses with complicated ARSA were found to have chromosomal numerical or structural abnormalities,with statis-tically significant difference between the two groups(P=0.024).Genetic analysis was completed in 48 isolated ARSA,and the positive rate of pathogenic copy number variants(CNV)was 4.2％(2/48),which was not signifi-cantly different from the pathogenic CNV incidence rate of 0.4％(1/239)in elderly pregnant cases during the same period(P=0.074).The Down syndrome positive likelihood ratio(LR+)for isolated ARSA was 2.5 and the Down syndrome LR+for complicated ARSA was 49.6.Conclusions:Complicated ARSA is often associated with cardiovascular abnormalities and is more likely to develop Down syndrome than isolated ARSA.Although the inci-dence of pCNV in isolated ARSA is slightly higher than the natural incidence,the correlation between pCNV and i-solated ARSA has not been clearly determined by the current sample size.

Fetomaternal hemorrhage (FMH) syndrome refers to a group of symptoms, including fetal anemia and maternal hemolytic transfusion reaction caused by fetal blood entering the maternal circulation through intervillous space. Diagnosis of FMH can be easily missed due to its non-specific symptoms and may lead to high perinatal mortality. The degree of fetal anemia and the volume of blood loss can be clinically evaluated by ultrasound measurement of middle cerebral artery peak systolic velocity and Kleihauer-Betke test. Clinical management is based on the degree of fetal anemia and gestational age. Intrauterine blood transfusion and termination are standard management. Fetal-maternal transfusion over 20 ml/kg is associated with fetal/neonatal morbidity or mortality. The incidence of FMH in twin pregnancy is rarely reported. We here report a case of dichorionic diamniotic twin pregnancy. Intrauterine death occurred to one of the twins because of FMH, and the other fetus was delivered at term with good outcome based on close monitoring.

Objective To study the colonization rate and antibiotic resistance of group B Streptococcus (GBS) in gravidas during late pregnancy,and to evaluate the effectiveness of GBS screening in late pregnancy and intrapartum antibiotic prophylaxis (IAP) for the prevention of neonatal early-onset GBS disease (EOGBS).Methods A retrospective study was conducted to analyze the colonization rate and antibiotic resistance pattern of GBS in 14 204 gravidas who were screened for GBS at 35-37 gestational weeks during March 2016 to March 2018 in the University of Hongkong-Shenzhen Hospital (HKU-SZH).Differences in the incidence of EOGBS before and after GBS screening and IAP were analyzed using Chi-square or Fisher's exact test.Results Among the 14 204 gravidas,2 027 cases were GBS positive with a colonization rate of 14.27％.Incidence rates of EOGBS before and after GBS screening were 0.6‰ (4/6 356) and 0.07‰ (1/14 403),respectively (Fisher's exact test,P=0.033).GBS isolates were 100％ (2 027/2 027) sensitive to penicillin and vancomycin.Resistance rates to clindamycin and erythromycin were 67.2％(1 363/2 027) and 65.7％ (1 332/2 027),respectively.Conclusions Routine GBS screening in late pregnancy and IAP can significantly decrease the incidence of EOGBS.Penicillin is the optimal choice for prevention and treatment of GBS infection.

Objective To investigate the safety and effectiveness of external cephalic version for breech presentation in singleton term pregnancies. Methods This study retrospectively analyzed the clinical data of 195 singleton pregnancies with gestational weeks ≥37 and breech presentation that has received external cephalic version in University of Hong Kong-Shenzhen Hospital from January 2014 to December 2016. The success rate of external cephalic version, delivery modes, maternal and neonatal complications and adverse outcomes were analyzed. Results Of the 195 cases, 62.6% (122/195) were successful, among which 107 vaginally delivered and 15 underwent the cesarean section. Maternal and neonatal outcomes of all 195 cases were good. The success rate of external cephalic version in the multipara was higher than that of the primipara [84.5%(71/84) vs 45.9%(51/111), χ2=30.383, P<0.001]. No neonatal asphyxiation or postpartum hemorrhage was reported. Conclusions External cephalic version is an effective and safe method to convert breech presentation and reduce cesarean section rate in the third trimester.

Objective To establish regression m odel betw een craniofacial lines and body height by m ea-suring craniofacial lines in Southw est H an m ales using C Tand to accum ulate data for the study of foren-sic anthropology. Methods H ead C Tdata of 273 H an m ales in Southw est w ere collected and 7 cranio-facial lines w ere determ ined. M ultiplanar reconstruction and volum e rendering w ere perform ed by im age post-processing softw are and the selected lines w ere m easured. The relationship betw een each m easuring indicator and body height w as analyzed using SPSS 21.0 softw are. The regression equation of body height estim ation w as established and 50 sam ples w ere selected again and put into the m athem atics m odels to verify its accuracy. Results The linear regression equations of 7 lines w ere established (P<0.05). The correlation coefficients of the unary linear regression equations w ere 0.190-0.439 and the standard errors of the estim ate (SEE) w ere 4.597-5.023 cm . The correlation coefficients of the m ultiple linear regression equation w ere 0.494-0.524 and the SEEw ere 4.418-4.458 cm . The return tests show ed that the highest ±1SEEaccuracy of the m ultiple regression equation:y=83.959+3.589 x6+2.573 x2, w ere 30%;and the highest ±2SEEaccuracy of the m ultiple regression equation: y=72.646+3.316 x6+1.586 x2+1.553 x4+2.211 x3, w ere 92% . Conclusion There is significant linear correlation betw een 7 selected lines and the stature in this study, and the plural linear regression equation established could be applied for estim ating the stature of Southw est H an m ales.

Objective To evaluate the feasibility,safety and effectiveness of modified associating liver partition and portal vein ligation for staged hepatectomy (ALPPS).Methods The published literatures associated with modified ALPPS were pooled from Embase,Pubmed,Medline,Google Scholar databases.The studies were included or excluded depends on our predetermined criteria.We selected data and performd descriptive analysis from the included studies.Results Five articles were included and reviewed.A total of 62 patients underwent five modified procedures,including monosegment ALPPS (m-ALPPS),anterior approach ALPPS,partial-ALPPS,radiofrequency-assisted liver partition with portal vein ligation (RALPP) and associating liver tourniquet and portal ligation for staged hepatectomy (ALTPS).There were 50 (80.6％) patients diagnosed liver metastatic colorectal cancer.The average operation interval of modified ALPPS was between 8 ～ 22 days and growth rate of future liver remnant (FLR) ranged from 48.7％ to 62.3％,the feasibility to perform ALPPS stage 2 was 98.4％.The incidence of severe postoperative complications were between 11.8％ ～33.3％.The 90-day mortality for monosegment ALPPS,partial-ALPPS and RALPP was 0,while the figure was 8.3％ in ALTPS.The in-hospital morbidities were 5.9％ and 8.3％ for anterior approach ALPPS and ALTPS,respectively,which were 0 in the other three modified groups.Clinical response evaluation,including R0 resection rate,overall survival rate,disease-free and recurrence rates were merely presented 83.3％,80％,50％,50％ in m-ALPPS group,while 100％,100％,95％,5％ in modified ALTPS group.Conclusion Modified ALPPS with improved safety is feasible in clinical practice.However,the effectiveness still needs further studies.

A three-dimensional finite element model of premaxillary bone and anterior teeth was established with ANSYS 13.0. The anterior teeth were fixed with strong stainless labial archwire and lingual frame. In the horizontal loading experiments, a horizontal retraction force of 1.5 N was applied bilaterally to the segment through hooks at the same height between 7 and 21 mm from the incisal edge of central incisor; in vertical loading experiments, a vertical intrusion force of 1.5 N was applied at the midline of lingual frame with distance between 4 and 16 mm from the incisal edge of central incisor. After loading, solution was done and displacement and maximum principle stress were calculated. After horizontal loading, lingual displacement and stress in periodontal membrane (PDM) was most homogeneous when the traction force was 14 mm from the edge of central incisor; after vertical loading, intrusive displacement and stress in PDM were most homogeneous when the traction force was 12 mm from the incisal edge of central incisor. The results of this study suggested that the location of center of resistance (CRe) of six maxillary anterior teeth is about 14 mm gingivally and 12 mm lingually to incisal edge of central incisor. The location can provide evidence for theoretical and clinical study in orthodontics.
Dental Models ; Dental Stress Analysis ; Finite Element Analysis ; Humans ; Incisor ; Maxilla ; Periodontal Ligament ; Tongue

Objective To analyze the complications of pregnant secondary cesarean in scar uterus,to provide theoretical guidance for cesarean section.Methods 160 pregnant women of secondary cesarean uterine scar were chosen as the study group.80 pregnant women of non-scar uterine were chosen as the control group.Results The bleeding volume during operation,operation time,operation fee,postoperative bleeding,uterine resection rate,neonatal asphyxia in study group were (432 ± 331) mL,(64 ± 21) min,(0.91 ± 0.11) million,(262 ± 187) mL,4.4％,11.9％,which in the control group were (361 ± 209) mL,(44 ± 16) min,(0.63 ± 0) million,(184 ± 132) mL,1.3％,6.3％ respectively,the differences were significant (t =2.52,8.19,26.10,4,4.76,x2 =3.98,all P ＜ 0.05).The two groups had no statistically significant difference in organ damage situation (P ＞ 0.05).Conclusion Secondary cesarean uterine scar easily lead to maternal blood loss and increased postoperative bleeding,prolonged surgery,increased hysterectomy rate,increased incidence of neonatal asphyxia and other complications.Pregnant uterine scar pregnancy is a high-risk pregnancy,pregnancy for maternal uterine scar secondary surgical indications should be strictly controlled.