AIM: To investigate the changes of transmural repolarization heterogeneity and ion currents in rabbits with left ventricular hypertrophy. METHODS: Ventricular hypertrophy was induced by a partial constriction of the abdominal aorta in rabbits. Myocytes were isolated by a two steps enzymological method. The sub-endocardial (Endo) and sub-epicardium (Epi) tissues were separated from other region (midmyocardium, Mid) with a razor. Whole cell patch clamp technique was used to record the action potential and ion currents. RESULTS: The action potentials duration at 90% repolarization (APD 90 ) of Epi, Mid and Endo were all prolonged significantly in hypertrophy group compared to control group. This prolongation of APD 90 was more pronounced in Mid (26.0%?2.7%) than that in Epi (14.0%?1.6%) and Endo (10.0%?1.1%). The transmural repolarization heterogeneity was increased significantly in the hypertrophy group. The I Ks and I to density in Epi, Mid and Endo was decreased significantly in hypertrophy group compared to those in control group. This decrease in I Ks and I to density was more pronounced in Mid than in Epi and Endo. No significantly difference of I Ca,L and I Kr density between hypertrophy group and control group in three layers was observed. The I K1 density decreased significantly in hypertrophy group compared to control group, but the extent of the decrease had no differences among the three layers. CONCLUSIONS: The transmural repolarization heterogeneity increases significantly in rabbit hypertrophied ventricle. The decrease in transmural heterogeneity of I to and I Ks is the main causes. [

Diversified teaching methods including traditional teaching,problem based learning,interactive teaching and team cooperation teaching were adopted in the process of teaching.Problem based learning can stimulate students' learning interests; interactive teaching can improve the students' hands-on ability and team cooperation teaching can cultivate students' cooperation spirits.Diversified teaching mode made different teaching methods integrated and complemented each other,forming a special teaching mode for the course of functional experiment.

Objective To analyze the factors for willingness to pay(WTP)in different quantiles and to provide evidence for formulating premium of minors covered by Urban Residents'Basic Medical Insurance.Methods In a field survey,the study adopted the contingent valuation method and quantile regression to measure and analyze the WTP.Results The influencing factors and degree of influence varied in different quantiles.Annual household income was significant in 10 of 11 quantiles with the maximum marginal effect of 350 yuan.Whether the insured comes from a village in a city affects 8 of the 11 quantiles whereas gender,age and health conditions of minors have minor effect on willingness to pay.Conclusion The premium standard should be raised from 40 yuan per person per year to 100 yuan.Minors can be categorized into subgroups and be set with distinct premiums in terms of the significant influencing factors and its influence degree.

Objectives:To investigate whether circumferential pulmonary vein isolation(CPVI)combined with additional ablation reduces the recurrence rate of atrial fibrillation(AF)compared with CPVI alone. Methods:A literature search was conducted using the databases CNKI,Wanfang Data,VIP,Chinese Biomedical Literature Database,PubMed,Embase,the Cochrane Library.Randomized controlled studies that met the standards in recent ten years were screened,and the relevant literature contents were meta-analyzed by Review Manager 5.3 software.The comparison results of CPVI alone with CPVI combined with the additional ablation strategies in the recurrence of AF were summarized. Results:A total of 21 literatures were included with 3 357 patients,of whom 1 580 underwent CPVI alone and 1 777 underwent CPVI combined with additional site ablation.The follow-up time was more than 1 year.Meta-analysis showed that there was no significant difference between CPVI alone and CPVI combined ablation strategies in reducing AF recurrence(OR=0.86,95%CI:0.73-1.01,P=0.06).Subgroup analysis based on additional ablation site,AF type,left atrial diameter,and AF diagnosis time showed that only in the small left atrial diameter subgroup,CPVI combined with additional ablation further reduced the recurrence rate of AF(OR=0.68,95%CI:0.47-0.98,P=0.04). Conclusions:The ablation strategy of CPVI combined with additional sites could not reduce the recurrence rate of AF compared with CPVI alone.

OBJECTIVE: To analyze the clinical and genetic characteristics of a child with clinical manifestations of hypoplasia, epilepsy and abnormal face. METHODS: The clinical data of the child were collected. The peripheral blood samples of the patient and his parents were extracted for high-throughput sequencing, and Sanger sequencing verification and bioinformatics analysis were performed to detect suspected pathogenic variants. RESULTS: The clinical manifestations of the child were overall developmental backwardness, seizures, autism, and special facial appearance. High throughput sequencing showed that there was a heterozygous mutation of exon 11: c.1920_c.1927delCCTCTACC (p.Ser641Rfs*31) of the DYRK1A gene. The same variant was found in neither of her parents, suggesting that it has a denovo origin. CONCLUSION The exon11: c.1920_c.1927delCCTCTACC (p.Ser641Rfs*31) mutation in DYRK1A gene was the genetic etiology of the case, which enriches the pathogenic gene spectrum of DYRK1A and provides the basis for clinical diagnosis and genetic counseling.
Arthrogryposis ; Child ; Facies ; Female ; Heterozygote ; Humans ; Intellectual Disability/genetics* ; Mutation

Objective To understand the pathogenicity and multilocus sequence typing (MLST) characteristics of the pathogenic strain of Burkholderia pseudomallei (Bp) in Hainan,and provide a reference for studying the structural characteristics and phylogenetic characteristics of pathogenic Bp in Hainan.Methods The data of patients with melioidosis in Hainan,who were treated in Hainan General Hospital from 2011 to 2018,and Bp pathogenic strains isolated from patient infected specimens were collected.The Bp pathogenic strains were genotyped by MLST method,and the distribution characteristics of the sequence type (ST) were analyzed.The ST of all Bp pathogenic strains was analyzed by eBURST v3 software to establish the evolutionary relationship map.Results A total of 91 cases of melioidosis patients were studied,including 76 males and 15 females;the ages were mainly concentrated in 40-70 years old;clinical manifestations included sepsis,pulmonary infection and local abscess;and the most common diseases were diabetes.A total of 91 Bp pathogenic strains were observed,of which 85 Bp pathogenic strains were distributed in coastal areas of Hainan,accounting for 93.41％;identified by MLST method,39 ST were discovered,the most common were ST46 (13 strains),ST55 (12 strains),STS0 (8 strains) and ST58 (7 strains),accounting for 14.29％,13.19％,8.79％ and 7.69％,respectively;except ST46 was widely distributed in the coastal areas of Hainan,the ST55,ST50 and ST58 were concentrated in the southwest,northeast and southeast regions of Hainan.Compared with the MLST database,ST30 (3 strains) was currently found only in Hainan,ST562 (4 strains) had been reported in northern Australia,and the remaining ST models had been reported in southeast Asia.The eBURST v3 software divided the 39 ST into 3 subtypes and 18 individual types.Among them,the subtypes with ST300 as the original type had the most number of ST,including 17 ST,57 Bp pathogenic strains;compared with the MLST database,the ST300 was mainly distributed in southeast Asian regions such as Thailand.Conclusions The ST of Bp pathogenic strains in Hainan has high regional diversity and genetic diversity,and is closely related to Bp in southeast Asian regions such as Thailand.

BACKGROUND:Deferoxamine mesylate is a potential anti-osteoporosis drug with iron chelation,vascular regeneration,and antioxidant effects.Recent studies have shown that the application of deferoxamine mesylate can be extended to the field of tissue regeneration engineering. OBJECTIVE:To investigate whether deferoxamine mesylate can promote the repair effect of iron overload osteoporotic rats after bone grafting for mandibular bone defects by simulating the state of iron accumulation in patients with postmenopausal osteoporosis with high iron intervention in osteoporotic rats. METHODS:An iron accumulation ovariectomized osteoporosis model was firstly constructed.The model group underwent bilateral ovariectomy,and the intraperitoneal injection of ferric ammonium citrate(90 mg/kg,twice a week,for 11 weeks)was started in the 2nd week,while the sham-operated group had some fat around the ovaries removed and was given an equal amount of saline for 11 weeks.After the successful modeling,the experimental rats were divided into sham-operated group(n=6),high iron ovariectomtized group(n=6)and high iron ovariectomized deferoxamine mesylate treatment group(deferoxamine mesylate group,n=6).Bone defects of 5 mm in diameter were established in the rat's bilateral mandibles and implanted with Bio-Oss bone powder.Intraperitoneal injection of deferoxamine mesylate(100 mg/kg,3 times a week)was started on postoperative day 4 in the deferoxamine mesylate group,and equal volume of saline was given in the sham-operated and high iron ovariectomized groups.The bone samples of the mandible,liver and blood were taken at 2 and 12 weeks after bone grafting for Prussian blue staining of the jaw and liver and ELISA detection of serum ferritin to detect iron levels in various body tissues;hematoxylin-eosin staining and Masson staining were performed to observe inflammatory cell infiltration and early osteogenesis in the bone defect area;tartrate resistant acid phosphatase staining was performed to observe osteoclast differentiation;ELISA was performed to detect serum calcitonin and type I collagen C-terminal peptide levels;and Micro-CT and hematoxylin-eosin staining were performed to observe osteogenesis in the middle and late stages. RESULTS AND CONCLUSION:The number of tibial trabeculae was reduced and the trabeculae were sparsely arranged in the high iron ovariectomized group.Iron levels in the liver,jaw bone and serum were significantly higher in the high iron ovariectomized group than the sham-operated group at 2 weeks after bone grafting,while the iron levels were significantly decreased after deferoxamine mesylate intervention(P＜0.05).In the early stage of bone defect repair,more inflammatory cell infiltration,less new bone matrix and less type I collagen fiber production were observed in the high iron ovariectomized group than in the sham-operated group(P＜0.05);after deferoxamine mesylate treatment,inflammatory cell infiltration was reduced,a small amount of new bone matrix was produced and collagen fibers increased significantly(P＜0.05).In the middle and late stages of bone defect repair,Micro-CT results showed a reduction in new bone production in the high iron ovariectomized group compared with the sham-operated group and increased new bone matrix after deferoxamine mesylate treatment(P＜0.05).Compared with the sham-operated group,the osteoclast number,serum calcitonin level,and serum type I collagen C-terminal peptide level were increased in the high-iron ovariectomized group,while the osteoclast number was decreased and bone metabolic indexes were improved after treatment with deferoxamine mesylate.To conclude,in ovariectomized rats with high iron intervention,elevated iron levels can be seen in multiple tissues,accompanied by reduced new bone production in the mandibular bone defect area.Deferoxamine mesylate can improve bone metabolism and inhibit osteoclast activity by removing iron deposits in tissues,improve bone formation in iron-accumulated osteoporotic rats,and promote bone healing in the mandibular bone defect area.

BACKGROUND:Interleukin-4 can promote the osteogenic effect of bone substitute materials,but its molecular mechanism is not yet clear.Further elucidating the mechanism of interleukin-4 promoting osteogenic effect can help find safe,economical,and effective methods for the regeneration treatment of alveolar bone defects in patients. OBJECTIVE:To explore the effect of interleukin-4 intervention on polarization transformation of macrophages and osteogenic differentiation of bone marrow mesenchymal stem cells and its possible mechanism. METHODS:RAW264.7 cells in the M1 group were induced with interferon gamma + lipopolysaccharide for 24 hours.RAW264.7 cells in the interleukin-4+M1 group were induced with interferon gamma + lipopolysaccharide for 24 hours and then interleukin-4 was added for 24 hours.RAW264.7 cells in the interleukin-4+AG+M1 group were induced with interferon gamma + lipopolysaccharide for 24 hours,and then interleukin-4 and AG-490,a JAK/STAT pathway inhibitor,were added for 24 hours.After intervention,immunofluorescence staining was used to analyze the expression of inducible nitric oxide synthase and CD206,the phenotypic marker protein of macrophages.ELISA kit was used to detect the expression of interleukin-10 and tumor necrosis factor-α in the supernatant of cell culture.The gene expressions of nodular receptor protein-3(NLRP3),interleukin-1β,and caspase-1 were detected by RT-qPCR.The expression levels of tyrosine protein kinase 1(JAK1)/phosphorylated tyrosine protein kinase 1(p-JAK1),signal transduction and transcription activator 6(STAT6)/phosphorylated signal transduction and transcription activator 6(p-STAT6),NLRP3,pro-interleukin-1β and pro-caspase-1 were detected by western blot assay.Then,RAW264.7 cells in the above four groups were indirectly co-cultured with bone marrow mesenchymal stem cells by transwell for 24 hours,followed by alkaline phosphatase staining and alizarin red staining.The mRNA expressions of alkaline phosphatase,collagen type I,and osteocalcin were detected by RT-qPCR. RESULTS AND CONCLUSION:(1)Immunofluorescence and ELISA results showed that interleukin-4 intervention could promote the expression of CD206 and interleukin-10 in M2 macrophages,and inhibit the secretion of inducible nitric oxide synthase and tumor necrosis factor-α.(2)RT-qPCR results showed that interleukin-4 could suppress the expression of NLRP3,interleukin-1β,and caspase-1 mRNAs.(3)Western blot assay showed that interleukin-4 could promote the expression of JAK1/p-JAK1,STAT6/p-STAT6 and NLRP3 proteins.(4)The alkaline phosphatase staining and alizarin red staining of bone marrow mesenchymal stem cells co-cultured with the interleukin-4+M1 group were significantly enhanced,and the mRNA expressions of alkaline phosphatase,collagen type I,and osteocalcin were significantly increased.It is concluded that interleukin-4 may inhibit the activation of NLRP3 by up-regulating JAK1/STAT6 pathway,thus promoting the transformation of macrophages from M1 polarization to M2 polarization,and finally enhancing the osteogenic differentiation ability of bone marrow mesenchymal stem cells.

ObjectiveTo investigate the intervention effect of Jiedu Tongluo Tiaogan prescription （JTTP） in protecting pancreatic β cells by targeting the bile acid Takeda G protein-coupled receptor 5 （TGR5）/cyclic adenosine monophosphate （cAMP） signaling pathway against NOD-like receptor protein 3 （NLRP3） inflammasome. MethodThirty-two male SPF-grade db/db mice were randomly divided into the model group， low-dose JTTP group （3.6 g·kg^-1）， high-dose JTTP group （7.2 g·kg^-1）， and metformin group （0.2 g·kg^-1）. Eight db/m mice were assigned to the blank control group. The mice were treated with drugs for 8 weeks， and fasting blood glucose （FBG） was measured every 2 weeks. Oral glucose tolerance tests （OGTT） were conducted after the last administration. Enzyme-linked immunosorbent assay （ELISA） was performed to detect fasting insulin （FINS）， and the homeostasis model assessment of β-cell function （HOMA-β）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， and IL-1β levels were calculated. Hematoxylin-eosin （HE） staining was used to observe pathological changes in mouse pancreatic tissue. Immunofluorescence was performed to detect insulin expression in mouse pancreatic tissue. Western blot and real-time quantitative polymerase chain reaction （Real-time PCR） were used to detect the expression of proteins and mRNAs of key targets in the TGR5/cAMP signaling pathway and NLRP3 inflammasome. ResultCompared with blank group， FBG， OGTT， FINS， IL-6， TNF-α and IL-1β in model group were significantly increased （P<0.01）. Compared with model group， after 6 weeks of drug treatment， FBG level in JTTP group and metformin group decreased significantly （P<0.01）. The results of OGTT experiment showed that compared with model group， the blood glucose levels of mice in each administration group were decreased at all time points （P<0.05， P<0.01）， and the levels of FINS， TNF-α and IL-6 in JTTP dose groups and metformin group were significantly decreased. The level of IL-1β in JTTP high-dose group and metformin group was significantly decreased （P<0.01）. Pancreatic pathology showed that the islets in the model group were irregular in shape， uneven in distribution， and showed signs of atrophy. The prognosis of JTTP was that the cell count increased and the boundary was clearer. Immunofluorescence results showed that the islet cells in the blank group were arranged in an orderly and full shape with appropriate insulin secretion， while the islet cells in model group were distorted in shape， atrophy in structure and less insulin secretion. The insulin content of mice in JTTP and metformin group was significantly increased. Compared with blank group， mRNA expressions of NLRP3， apoptosis-related spot-like protein （ASC） and Caspase-1 in pancreatic tissues of model group were significantly increased （P<0.01）. Compared with model group， JTTP high-dose group and metformin group promoted the up-regulation of TGR5 and cAMP mRNA， and down-regulated the mRNA expressions of NLRP3， ASC and Caspase-1 （P<0.05， P<0.01）. Compared with blank group， the expression of TGR5 protein in model group was significantly decreased （P<0.01）. Compared with model group， TGR5 protein in JTTP high-dose group and metformin group was significantly increased （P<0.01）.

Objective:To study the genomic sequence of Coxsackievirus A8 (CV-A8) associated with hand, foot and mouth disease (HFMD) from 2013 to 2018 in China and to analyze the genetic evolution of each coding region of the full-length genome.Methods:The genome sequences of 11 CV-A8 strains isolated from patients with HFMD in different regions of China from 2013 to 2018 were determined. Sequence alignment and genetic evolution analysis were performed by Sequencher 5.0 and MEGA 7.0 software, etc.Results:Sequence alignment showed that the genome length of 11 CV-A8 strains ranged from 7 393 bp to 7 400 bp. There was no base insertion or deletion in the coding region compared with the prototype strain, but there were individual base insertion or deletion in the non-coding region. The nucleotide and amino acid similarities in the VP1 region of 11 CV-A8 strains were 78.3%-98.6% and 92.6%-99.7%, respectively, and the nucleotide and amino acid sequences identities with the CV-A8 prototype strain were 78.3%-98.2% and 92.6%-99.7%, respectively. Based on the phylogenetic analysis of VP1 region sequences, the CV-A8 can be divided into five genotypes: A, B, C, D and E. The 11 CV-A8 strains in this study belonged to genotypes C (1 strain), D (2 strains) and E (8 strains). The nucleotide and amino acid similarities of 11 CV-A8 full-length genomes were 81.3%-98.8% and 95.9%-99.5%, respectively. The phylogenetic tree of the P2 region showed that the eight E genotypes CV-A8 had the closest evolutionary distance with CV-A4, CV-A14, and CV-A16. The phylogenetic tree of the P3 region showed that the eight E genotypes CV-A8 had a close evolutionary distance with CV-A5, CV-A16, CV-A14 and CV-A4.Conclusions:The 11 CV-A8 stains in this study showed significant intra-genotype diversity in capsid region and recombinant diversity in non-capsid region which indicated that CV-A8 quasispecies were still undergoing dynamics variation. CV-A8 may become an important pathogen of HFMD and the monitoring of CV-A8 needs to be further strengthened.