AIM:To investigate the mechanism by which muscle segment homeobox 2(Msx2)regulates the differentiation of outer enamel epithelial cells in the enamel organ.METHODS:Tissue paraffin sections were prepared and subjected to hematoxylin-eosin(HE)staining to analyze the effect of Msx2 deficiency on the differentiation status of epithelial cells in the enamel organ at the morphological level.At the ultrastructural level,alterations in cell structure were analyzed.The intermediate steps mediating cell differentiation were identified.Transcriptome sequencing analysis was performed to validate the molecular mechanisms underlying the observed phenomena.RESULTS:Msx2 deficiency was innovatively found to induce severe squamous epithelial hyperplasia in outer enamel epithelial cells of enamel organ,accompanied by dynamic restructuring of the cell cytoskeleton and alterations in cell adhesion at the ultrastructure level.As a transcriptional repressor,the loss of Msx2 expression results in significant increases(P＜0.05 or P＜0.01)in the mRNA expression levels of integrin β2(Itgβ2),ItgαM,Itgα4,Rac family small GTPase 2(Rac2),Rac/Cdc42 guanine nucleo-tide exchange factor 6(Arhgef6)and protein tyrosine phosphatase receptor type C(Ptprc).CONCLUSION:Msx2 regu-lates cytoskeleton structure and cell-cell interaction through the Rho GTPases signaling pathway,thereby influencing the differentiation state of outer enamel epithelial cells.This study reveals the mechanism through which Msx2 regulates the differentiation of outer enamel epithelial cells,providing a theoretical foundation for the prevention and treatment of enam-el-related clinical dental diseases.

AIM:To investigate the mechanism by which muscle segment homeobox 2(Msx2)regulates the differentiation of outer enamel epithelial cells in the enamel organ.METHODS:Tissue paraffin sections were prepared and subjected to hematoxylin-eosin(HE)staining to analyze the effect of Msx2 deficiency on the differentiation status of epithelial cells in the enamel organ at the morphological level.At the ultrastructural level,alterations in cell structure were analyzed.The intermediate steps mediating cell differentiation were identified.Transcriptome sequencing analysis was performed to validate the molecular mechanisms underlying the observed phenomena.RESULTS:Msx2 deficiency was innovatively found to induce severe squamous epithelial hyperplasia in outer enamel epithelial cells of enamel organ,accompanied by dynamic restructuring of the cell cytoskeleton and alterations in cell adhesion at the ultrastructure level.As a transcriptional repressor,the loss of Msx2 expression results in significant increases(P＜0.05 or P＜0.01)in the mRNA expression levels of integrin β2(Itgβ2),ItgαM,Itgα4,Rac family small GTPase 2(Rac2),Rac/Cdc42 guanine nucleo-tide exchange factor 6(Arhgef6)and protein tyrosine phosphatase receptor type C(Ptprc).CONCLUSION:Msx2 regu-lates cytoskeleton structure and cell-cell interaction through the Rho GTPases signaling pathway,thereby influencing the differentiation state of outer enamel epithelial cells.This study reveals the mechanism through which Msx2 regulates the differentiation of outer enamel epithelial cells,providing a theoretical foundation for the prevention and treatment of enam-el-related clinical dental diseases.

BACKGROUND:For elderly patients with traumatic hip fractures,the related factors of prognosis are very complex,and the integrity of the lateral wall is one of the influencing factors.It is of important clinical value to understand the effect of lateral wall injury on the prognosis of femoral intertrochanteric fracture. OBJECTIVE:To evaluate the relationship between the integrity of the lateral wall and hip functional recovery and other outcomes in patients with femoral intertrochanteric fractures. METHODS:Totally 82 patients with femoral intertrochanteric fractures were screened and all patients received proximal femoral nail antirotation fixation.According to the thickness of the lateral wall,the patients were divided into the lateral wall intact group(n=31)and lateral wall risk group(n=51).The perioperative indexes,weight-bearing time,fracture healing time,hip joint function and range of motion,postoperative pain and complications were compared between the two groups. RESULTS AND CONCLUSION:(1)The time of hospitalization and the number of fluoroscopies during operation in the lateral wall intact group were significantly lower than those in the lateral wall risk group(P<0.05),but there was no significant difference in other perioperative indexes.(2)Both groups were able to get down to the ground early after surgery and finally complete weight-bearing,but in the lateral wall risk group,the time of fracture healing was longer;the time of complete weight-bearing was significantly delayed;the Harris score of the last follow-up was lower;the range of motion of hip extension and flexion and neck trunk angle on the affected side were smaller(P<0.05).(3)There was no significant difference in the incidence of postoperative complications between the two groups,but the overall incidence of complications in the lateral wall intact group was significantly lower(P<0.05).(4)In summary,after internal fixation of proximal femoral nail antirotation,patients with the intact lateral wall had a relatively better prognosis than those with risk lateral wall.

Objective A porcine vocal cord injury model was established to analyze and compare the damage range of porcine vocal cords and the repair process after vocal cord injury caused by CO2 laser surgery and radiofre-quency ablation with plasma spot excitation technology.Methods Fifteen pigs,30 sides of vocal cords,were used in this study.The bilateral vocal cords of the same pig were divided into CO2 laser and radiofrequency coblation(RFC)groups respectively.CO2 laser and radiofrequency ablation with plasma spot excitation technology were used to perform ubligamental cordectomy.Three pigs were sacrificed after anesthesia on postoperative day 1 and postop-erative 3,6,9,and 15 weeks.The vocal cords were harvested for HE staining.The depth of edema degeneration zone and the fibrous tissue thickness were measured vertically in the two groups,and the postoperative vocal cord damage range and vocal cord repair process were compared between the two groups.Results The depth of edema degeneration zone in the CO2 laser group was deeper than that in the RFC group at 1 day postoperatively(P＜0.01).There was no significant difference in the depth of the edema degeneration zone between the two groups at the 3rd,6th,and 9th weeks after operation(P＞0.05).The depth of the edema degeneration zone at 3rd weeks postoperatively was less than that at 1 day postoperatively,and at 6th weeks postoperatively was less than that at 3rd weeks postoperatively for both operation modes(P＜0.05).There was no statistically significant difference be-tween 9th weeks postoperatively and 6th weeks postoperatively(P＞0.05).At the 15th week after operation,the fibrous tissue thickness of the vocal fold lamina propria in the RFC group was thinner than that in the CO2 laser group(P＜0.01).Conclusion Radiofrequency ablation with plasma spot excitation technology causes less damage to porcine vocal fold than CO2 laser.There is no significant difference between the two operation modes in terms of postoperative repair process,while the fibrous tissue in the lamina propria of the vocal fold is thinner in the RFC group when a vocal fold scar is formed.

Objective To investigate the inhibitory effect and molecular mechanism of Huaier granule on the growth of sorafenib resistant hepatocellular carcinoma (HCC) cells. Methods The gradient concentration of Huaier granule was used to treat HCC cells, and the effect of Huaier granule on the proliferation, migration and invasion of sorafenib resistant HCC cells was analyzed. Bioinformatics methods were used to analyze the possible interaction between microRNA-31-5p (miR-31-5p) and sprouty-related proteins with an EVH1 domain 1 (SPRED1). The expression levels of miR-31-5p and SPRED1 in HCC cells were detected by real time fluorescence quantitative polymerase chain reaction (qRT-PCR); cell viability, proliferation, migration, invasion and apoptosis were detected by CCK-8, colony formation, scratch healing, Transwell and flow cytometry; RNA immunoprecipitation (RIP) assay and dual luciferase assay were used to verify the binding relationship between miR-31-5p and SPRED1. Results Huaier granule could significantly inhibit the proliferation, migration and invasion of sorafenib resistant HCC cells, and induce apoptosis. Bioinformatics analysis showed that miR-31-5p was highly expressed in HCC, and Huaier granule was able to down-regulate the expression of miR-31-5p, inhibit the proliferation and metastasis of sorafenib resistant HCC cells, and induce apoptosis; miR-31-5p showed a targeted inhibition effect on the expression of SPRED1. SPRED1 was down-regulated in HCC, and overexpression of SPRED1 was able to reverse the promoting effect of overexpression of miR-31-5p on proliferation and metastasis of sorafenib resistant HCC. Conclusion Huaier granule can inhibit sorafenib resistant HCC metastasis through the miR-31-5p/SPRED1 axis, indicating that Huaier granule has the potential to be used as a novel drug for HCC treatment.

Objective To explore and analyze the clinical characteristics of extremely premature infants at low risk for early-onset sepsis (EOS) , so as to avoid overuse of antibiotics. Method The clinical data of extremely premature infants hospitalized from January 1, 2010 to December 31, 2017 were collected. Extremely premature infants born from mothers without premature rupture of membranes and without maternal clinical manifestations of chorioamnionitis during pregnancy were classified assigned into the low-risk group, and those who did not meet the low-risk conditions were regarded assigned intoas the control group. EOS was diagnosed according to the results of blood culture within 72 hours after birth. The clinical characteristics, treatment and outcome of extremely premature infants between the two groups were retrospectively analyzed. Results A total of 245 extremely preterm infants were enrolled, including 153 (62.4％) in low-risk group. Compared with the control group, mothers in low-risk group had higher rates of gestational diabetes and hypertension, higher rates of antenatal hormone use and lower rates of antenatal antibiotics use; furthermore, neonates in low-risk group had lower rates of Apgar score ＜ 5, higher rates of pulmonary surfactant use, respiratory support and mechanical ventilation, and lower risk of death and incidence of early-onset sepsis. The differences were statistically significant (P＜0.05) . Among In extremely premature infants whose having survival time＞ 24 hours, compared with control group, infants in low-risk group had higher incidences of respiratory distress syndrome, patent ductus arteriosus, intracranial hemorrhage and bronchopulmonary dysplasia, and lower incidence of pulmonary hemorrhage than control group, and the differences were statistically significant (all P＜0.05) . In low-risk group, the risks of death, respiratory distress syndrome, pulmonary hemorrhage and bronchopulmonary hemorrhage in long-term antibiotic group were higher than the short-term antibiotic group. Conclusion Early identification of extremely preterm infants at low risk of early-onset sepsis in extremely preterm infants is of clinical significance in reducing early empirical use of antibiotics therapy.

Objective To assess the effectiveness of iterative metal artifact reduction (IMAR) on metal artifacts reduction in thorax scan.Methods Thoracic phantom with two pedicle screws implanted in both sides of the T5 vertebrae was used,with the scan parameters of 130 kV and CARE Dose 4D,the phantom was scanned with and without the screws respectively.Images without screws were reconstructed with FBP.Images with screws were reconstructed with FBP and IMAR respectively.Three ROIs were selected on tissues including aorta,pulmonary and paravertebral soft tissue on image slice adjacent to the screws.The CT value and standard deviations (noise) of ROIs were measured,and the deviation of CT value (△HU) was calculated as the difference between CT values in images with and without screws.Twenty-six cases who received chest CT examination and with pedicle screw implant in scanning range were collected.The scanning parameters and image reconstruction methods were the same as phantom scan.The CT value (HU) of metal artifacts adjacent to vertebrae and dorsal soft tissue was measured,and the image quality of reconstructed image by two skilled radiologists independently was evaluated.Results In the phantom after implanted screws,the noise were significantly reduced by IMAR compared to FBP in all the three ROIs of aorta,pulmonary and paravertebral soft tissue (P＜0.05),and the △HU was significantly smaller in IMAR compared to that with FBP (P＜0.01).In 26 patients,there were significant differences in CT value of vertebral bone tissue and dorsal soft tissue between FBP and IMAR (P＜0.05),and the subjective evaluation scores of the two image reconstruction methods showed a statistically significant difference (P＜0.05).Conclusion IMAR can significantly reduce streak artifacts of metal implant and adjuste the CT values of artifact affected tissues to make it more close to the true value without metal implant.

The prevalence of stroke is increasing in China and the world,and cognitive impairment,as one of the most common complications of stroke,has attracted much attention of many researchers.Post-stroke cognitive impairment (PSCI) has severely affected patients' daily living ability,which has brought heavy burden to family and society.In addition,with the increasing of age,PSCI may even develop into dementia,so we need to give early diagnosis,early treatment and prevention to patients with PSCI.In this paper,the concept of PSCI,neuropsychological characteristics,screening scale and treatment are described to improve the staff awareness and management of PSCI.

Neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) is an autosomal recessive disease caused by SLC25A13 gene mutations, and is characterized by delayed jaundice clearance, liver dysfunction, and elevated aminoacidemia. The confirmed diagnosis depends on gene analysis. Citrin deficiency is one of the important causes of neonatal intrahepatic cholestasis in China. Recently more and more researches about NICCD were reported. The paper summarized the epidemiology, pathogenesis, clinical characteristics, and progresses in diagnosis and treatment of NICCD.