Objective To explore the effectiveness and adverse effect of high frequency oscillation ventilation (HFOV) combined with Sildenafil (SIL) treatment on newborns with persistent pulmonary hypertension (PPHN).Methods A total of 89 cases of PPHN infants collected from Chengdu Women and Children's Central Hospital from Sep.2010 to Sep.2012 were randomly divided into HFOV group,constant mechanical ventilation (CMV) group,HFOV combined SIL group (HFOV + SIL group) and CMV combined with SIL group (CMV + SIL group).The arterial blood gas,pulmonary artery pressure (PAP) and adverse reactions were monitored before and 3 days after treatment.SNK multiple comparison method andx2 test were performed for data before and after treatment among groups for continuous variables and categorical variables,respectively.Results The levels of pa (O2) [(79.1 ± 13.7) mmHg (1 mmHg =0.133 kPa),(77.9 ±14.6) mmHg,(85.4 ±15.2) mmHg],Sa(O2) [(87.8 ±13.4)％,(88.4±15.6)％,(96.1±15.9)％],pa(CO2)[(42.5±11.3) mmHg,(40.2 ±10.5) mmHg,(35.6 ±8.7) mmHg] and PAP [(31.1 ± 8.1) mmHg,(30.4 ± 9.5) mmHg,(25.8 ± 7.3) mmHg] were all improved significantly in CMV + SIL group,HFOV group and HFOV + SIL group compared with those in CMV group[(69.9 ± 12.3) mmHg,(81.1 ± 14.9)％,(48.1 ±9.5) mmHg,(35.6 ±8.9) mmHg] (F =4.629 3,3.673 2,5.865 3,4.849 5,P ＜0.05),especially for HFOV + SIL group(P ＜ 0.05).No significant difference in such indicators was observed between CMV + SIL group and HFOV group (P ＞ 0.05).The effective rate in HFOV + SIL group (90％) was the highest among the 4 groups (x2 =7.938,P ＜ 0.05).During the treatment,all neonates have no adverse reaction.Conclusion The combined use of SIL and HFOV might be a more effective and safer method in the treatment of PPHN of neonate.

BACKGROUND:It was found that the ligands and receptors of Notch are both cell membrane surface proteins,which are important proteins to mediate intercellular communication,and the Notch signaling pathway plays a crucial regulatory role in the proliferation and differentiation of mesenchymal stem cells. OBJECTIVE:To review the regulatory mechanism of the Notch signaling pathway on the proliferation and differentiation of mesenchymal stem cells,summarize and clarify the research advance in how the Notch signaling pathway regulates the proliferation and differentiation of mesenchymal stem cells,and provide theoretical support for the future use of stem cells to treat various related diseases. METHODS:By using the computer,the first author searched the relevant studies involving Notch signaling pathway regulation of mesenchymal stem cell proliferation and differentiation on CNKI,Wanfang,VIP,PubMed,Web of Science,and Nature databases with Chinese search terms"mesenchymal stem cells,Notch,Notch signaling pathway,proliferation,differentiation"and the English search terms"mesenchymal stem cells,MSC,Notch,Notch signaling pathway,proliferation,differentiation".Part of the literature was searched in combination with the literature tracing method.Finally,87 articles were included in the review analysis. RESULTS AND CONCLUSION:(1)Notch signaling pathway is a conserved signaling pathway in multicellular organisms,which plays an important role in regulating cell differentiation,proliferation,apoptosis,and the cell cycle by mediating communication between neighboring cells through receptor-ligand binding.(2)Mesenchymal stem cells are a class of adult stem cells with self-proliferative and multi-directional differentiation potential,which can be regulated by external signaling pathways to affect their proliferation and differentiation.Notch signaling pathway,as one of them,when Notch ligands are activated,the Notch proteins will undergo two protein hydrolysis cleavages to release Notch intracellular structural domain NICD,which then enters the nucleus and thus promotes the transcription of target genes to regulate the proliferation and differentiation of mesenchymal stem cells from different sources,such as bone marrow,adipose,and umbilical cord.However,the specific mechanisms that regulate the proliferation and differentiation of mesenchymal stem cells from different tissue sources of the same species are different.(3)The Notch signaling pathway can regulate the differentiation of mesenchymal stem cells into different target cells,but due to different target cells,the expression levels of receptors or ligands in the Notch signaling pathway vary.(4)Clinical targeting of the Notch signaling pathway to promote mesenchymal stem cells for the treatment of various refractory diseases,such as aplastic anemia,severe joint injuries,ischemic strokes,and myocardial infarctions,has a promising application.(5)By exploring the Notch signaling pathway via regulating the expression levels of its receptors and ligands in bone marrow mesenchymal stem cells from rat,mouse,and human,it can be found that the Notch signaling pathway expression levels in the proliferation and differentiation of mesenchymal stem cells from different species origins are also different.(6)The role of mesenchymal stem cells in tissue engineering has been gradually highlighted due to their advantages of safety,low immune rejection,and wide therapeutic prospects.The Notch signaling pathway regulates the proliferation and differentiation of mesenchymal stem cells with a wide range of influencing factors,and subsequent studies should further optimize the influencing factor variables and explore the standardized studies of regulating the proliferation and differentiation of mesenchymal stem cells.

Endodontic diseases are a kind of chronic infectious oral disease.Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha.However,it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy(RCT).Recent research,encompassing bacterial etiology and advanced imaging techniques,contributes to our understanding of the root canal system's anatomy intricacies and the technique sensitivity of RCT.Success in RCT hinges on factors like patients,infection severity,root canal anatomy,and treatment techniques.Therefore,improving disease management is a key issue to combat endodontic diseases and cure periapical lesions.The clinical difficulty assessment system of RCT is established based on patient conditions,tooth conditions,root canal configuration,and root canal needing retreatment,and emphasizes pre-treatment risk assessment for optimal outcomes.The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT.These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.