Effect of dura mater on enhancement of cranial osteogenesis in rats / 中国组织工程研究

BACKGROUND:The dura mater and skull are physically and functionally related,although there have been few investigations on primary extraction of dura mater and cranial cells,as well as co-culture of the two.The use of primary cells to investigate the influence of the dura mater on the skull is novel,and it is hoped that it may give a theoretical foundation for therapeutic therapy. OBJECTIVE:Rat dura mater and cranial bone cells were retrieved in situ to observe the influence of dura mater on cranial bone proliferation and differentiation,as well as to get a basic knowledge of the involvement of Twist1 in this process. METHODS:The enzyme digestion method was used in conjunction with the tissue block method to extract dural cells and cranial osteoblasts from rats within three days of birth.Immunofluorescence staining was used to identify the extracted cells,and alizarin red staining was used to identify and evaluate cranial osteoblasts and their mineralization ability.After co-culturing dural cells and cranial osteoblasts,real-time PCR was utilized to identify the expression of genes associated to cranial osteoblast proliferation and osteogenesis,as well as Twist1. RESULTS AND CONCLUSION:(1)Morphology:The retrieved dural cells had morphological traits similar to fibroblasts,while the osteoblasts were spindle-shaped.(2)Cell identification:immunofluorescence staining revealed that extracted dural cells expressed high levels of vimentin and cranial osteoblasts expressed high levels of alkaline phosphatase;cranial osteoblasts were stained with alizarin red 28 days after osteogenic induction,and obvious mineralized nodules were observed.(3)Real time PCR detection showed that the co-culture group had higher levels of PCNA,alkaline phosphatase,and RUNX2 mRNA expression than the control group(P＜0.01);however,Twist1 mRNA expression was lower(P＜0.01).(4)The findings showed that the primary extracted cranial osteoblasts had a high mineralization capacity,and that the dura mater was a key factor in promoting cranial growth and development and osteogenic differentiation,with Twist1 playing a key role in this process.

Effect of reperfusion therapy on differential expression of plasma exosomal miRNAs in patients with acute myocardial infarction / 中华老年心脑血管病杂志

Objective To observe the effect of coronary reperfusion therapy on the differential ex-pression of plasma exosomal miRNAs in patients with acute myocardial infarction(AMI).Meth-ods Three elderly male AMI patients undergoing coronary reperfusion therapy in our hospital from October to November 2022 were recruited in this study.The venous blood samples were col-lected at admission and 2 and 24 h after recanalization.MiRNA-sequencing was used to screen the differentially expressed miRNAs which were commonly expressed in the plasma exosomes of the 3 patients.Bioinformatics analysis was performed on the target genes,and then the differentially expressed miR-499a-5p was verified by qPCR.Results Compared with the plasma exosomal miRNAs at admission,there were 418 up-regulated and 406 down-regulated miRNAs at 2 h after operation,and 320 up-regulated and 225 down-regulated miRNAs at 24 h after operation(P＜0.05);Compared with the miRNAs at 2 h after operation,there were 344 up-regulated and 350 down-regulated ones at 24 h after operation(P＜0.05).Kyoto Encyclopedia of Genes and Ge-nomes enrichment analysis showed that the differentially expressed miRNAs were enriched in phosphatidylinositol-3-kinase-protein kinase B,hypoxia-inducible factor 1,and vascular smooth muscle contraction pathways.Gene Ontology analysis indicated that the molecular functions of dif-ferentially expressed miRNA target genes were mainly enriched in protein binding and DNA bind-ing;cellular components were mainly enriched in cell membrane and cytoplasm;and biological processes were mainly enriched in signaling and transcription of DNA templates.The miR-499a-5p level was significantly lower at 2 h postoperatively than at admission[(0.577±0.020)vs(1.000± 0.023),P＜0.05],and at 24 h postoperatively than at 2 h postoperatively[(0.068±0.006)vs(0.577±0.020),P＜0.05].Conclusion Plasma exosomal miRNAs can be used as a biomarker for early diagnosis of elderly AMI patients and for predicting the efficacy of reperfusion therapy.

Effects of 5-Aza-CdR on hippocampal neurogenesis in mice via the Notch1 pathway / 中国比较医学杂志

Objective To investigate the effect of 5-Aza-CdR on Notch1 pathway and neural regeneration and to explore the effects of 5-Aza-CdR on learning memory ability in mice by exploring active avoidance behavior.Methods Sixty 6～8-week-old SPF-grade ICR male mice were divided into two groups.5-Aza-CdR was administered to one group of mice via lateral ventricular injection,while the control group was injected with bovine serum albumin.Notch1 and HES1 mRNA and protein expression levels were detected by Real-time PCR and Western blot 24 hours after injection;5-bromo-2'-deoxyuridine-positive cells were observed by laser confocal microscopy,and Notch1 expression in hippocampal dentate gyrus was viewed with laser confocal microscopy.Notch1 methylation changes were detected by ethylation-specific PCR,and learning and memory behaviors of mice were assessed by passive avoidance tests and shuttle avoidance assays.Results Injection of 5-Aza-CdR increased hippocampal Notch1 pathway activity,promoted neuronal regeneration in the DG region,decreased methylation levels in the Notch1 promoter region,and enhanced the ability of mice to perform active avoidance behavior.Conclusions The effect of 5-Aza-CdR on active avoidance behavior may be related to the influence of hippocampal neural regeneration through the Notch 1 pathway.

The neuroprotective effect of sodium pyruvate on mouse hippocampal neural HT22 cells / 中国药理学通报

Aim To study the effect of sodium pyruvate on apoptosis and autophagy of HT22 in mouse hippocampal neuronal cells under hypoxia conditions. Methods HT22 cells were incubated with different concentrations of sodium pyruvate to detect their cellular activity by MTS; iron staining was used to further observe the effect of sodium pyruvate on HT22 cells in mitochondrial metabolism; lysosomal staining was applied to detect the lysosomal changes of sodium pyruvate on HT22 cells; Western blot was used to detect the expression of Bcl-2, Bax and LC3-II/LC3- I proteins. Results To verify whether sodium pyruvate exerted neuroprotective effects on mouse hippocampal HT22 cells through affecting mitochondrial apoptosis and autophagy pathways, which were improved by administration of sodium pyruvate. Conclusions Sodium pyruvate administration under hypoxic conditions can reduce the neuroprotective effect of hypoxic injury by reducing apoptosis and activating autophagy in HT22 cells.

The mechanism of FAK/Twist1 signal pathway in the closure of cranial suture / 安徽医科大学学报

Objective@#To investigate the function of FAK / Twist1 signaling pathway during craniosynostosis closure.@*Methods@#Ten days old rats were divided into a control group (n = 50) and a rotation group (n = 50) . Both of them were made a approximately 0. 5 cm circle bone window at the midpoint of the lambdoid suture of the rat.The bone flaps were left free without damaging the dura mater. The bone flaps in the control group were repositioned in situ , and the bone flaps in the rotation group were rotated 180 ° and repositioned 3 weeks later. Then the experiments were performance as followed :open field test , measurement of body weight , head circumference , bone flap area , and thickness of bone flap in the two groups , observation of cranial suture closure by microscopy and HE staining , FAK / Twist1 expression determined by Western blot , real⁃time PCR , and immunohistochemical staining in the bone flap and dure , respectively. @*Results@#The cranial sutures was completely closed in the rotation groupand that was open in the control group through detecting by microscopic examination and HE staining. The thickness of the bone flap in the derotation group was greater than that in the control group , with statistical significance (P < 0. 01) . There were no significant differences between two groups in head circumference , weight , bone flap area , and operative area. The results of behavioral test showed that after the closure of cranial suture , the acsion of FAK was significantly increased in the calvaria and dura as well as Twsit1 was significantly decreased in the dura in rotating group measuring by Western blot , real⁃time PCR , and immunohistochemical staining (P < 0. 05) .@*Conclusion@#FAK/Twist1 may play an important role in craniosynostosis after rotation.

Study on the mechanism of FAK⁃PI3K/AKT signal pathway in the growth and development of neonatal rat cranial bone / 安徽医科大学学报

Objective@#To explore the growth characteristics of rat calvaria by detecting the calvaria of SD rats in different periods.@*Methods@#The calvaria of SD rats at 1 , 4 , 7 , 10 , and 12 weeks from the same littermate were selected (3 rats per week) . Real⁃time PCR and Western blot techniques were used to detect the expression of focal adhesion kinase ( FAK) Ⅳ phosphatidylinositol 3 kinase/protein kinase B ( PI3K/AKT ) signal pathway in the calvaria , and the role of FAK⁃PI3K/AKT in the growth and development of the calvaria was analyzed by correlation.@*Results@#The increase of brain volume and the thickness of calvaria increased synchronously , the expression of FAK was positively correlated with the changes of meridians , and the expression of FAK was positively correlated with the expression of PI3K/AKT.@*Conclusion@#The expression of FAK is related to the growth and development of rat skull. FAK plays a role in calvaria by activating PI3K/AKT signal pathway. FAK may be used as a marker of rapid skull growth and development , which provides a basic theoretical basis for the timing of clinical skull defect repair and treatment.

Effect of calcium dobesilate in preventing contrast-induced nephropathy in patients with diabetes and chronic kidney disease

OBJECTIVES: This study assessed the protective effect of calcium dobesilate against contrast-induced nephropathy (CIN) after coronary angiography (CAG) or percutaneous coronary intervention (PCI) in patients with diabetes and chronic kidney disease (CKD). METHODS: A total of 130 patients with diabetes and CKD estimated glomerular filtration rate: 30-90 mL/min/1.73m2 were enrolled and included in the analysis. They were divided into experimental (n=65) and control groups (n=65). Patients in the experimental group were administered oral calcium dobesilate (500 mg) three times daily for 2 days before and 3 days after the procedure. The serum creatinine (SCr), cystatin C (Cys C), and neutrophil gelatinase-associated lipocalin (NGAL) levels were measured before and after the procedure. RESULTS: The mean SCr level at 24h after the procedure was found to be significantly lower in the experimental group than in the control group (79.1±19.6 μmol/L vs. 87.0±19.3 μmol/L, p=0.023). However, the Cys C and NGAL levels were not significantly different between the two groups at all measurement time points (all p>0.05). The incidence of CIN defined by the SCr level was significantly lower in the experimental group than in the control group (3 [4.6%] vs. 13 [20.0%], p=0.017). However, the incidence of CIN defined by the Cys C level was not statistically different between the two groups (7 [10.8%] vs. 7 [10.8%], p=1.000). CONCLUSIONS: This study revealed that calcium dobesilate has no preventive effect against CIN in patients with diabetes and CKD.

Toxic effect of nano-cerium oxide on zebrafish embryonic early development / 中国职业医学

OBJECTIVE: To study the effect of nano-cerium oxide on the early development of zebrafish embryos. METHODS: The well-developed zebrafish embryos were randomly divided into the control group and the 50, 100, 200, 400 and 800 mg/L dose groups, with 40 embryos in each group. The dose groups were treated with nano-cerium oxide at the corresponding mass concentration for 5 days. The control group received no treatment. The death and malformation of embryos were observed. The heart rate of zebrafish embryos was recorded using confocol microscope. The protein expression of microtubule-associated protein 1 light chain 3(LC3) and cleaved Caspase-3 and were observed by Western blot technology. RESULTS: The death and embryonic malformation rate of zebrafish embryos increased with the increase of doses, showing statistical significance(P<0.01). The heart rate of the 800 mg/L dose group was decreased compared with the control group [(77±8) vs(93±4) beats/min, P<0.01]. There was no statistical significant difference in LC3-Ⅱ protein expression in each groups(P>0.05). The cleaved Caspase-3 protein expression increased in all dose groups compared with the control group(P<0.05). The cleaved Caspase-3 protein expression in the 200 mg/L dose group was higher than that in the 50 mg/L dose group(P<0.05). CONCLUSION: The nano-cerium oxide may induce cell apoptosis, causing toxic effect in early development of zebrafish embryos.

Qualitative evaluation of Forsythia suspensa by HPLC-PDA fingerprint combined with UFLC-Q-TOF-MS qualitative identification / 中国中药杂志

The analysis of Forsythia suspensa was performed on Waters Symmetry C18 column( 4. 6 mm×250 mm,5 μm) and mobile phase was methanol( A)-0. 1% formic acid aqueous solution( B) with the elution gradient. Column temperature was maintained at 30℃,and the flow rate was 1. 0 m L·min-1 with detection wavelength 265 nm. The HPLC-PDA fingerprint of F. suspensa was optimized.Chemical constituents in F. suspensa were analyzed by UFLC-Q-TOF-MS in positive and negative ion mode. The quality of 48 batches of F. suspensa from different habitats,processing methods and specifications was evaluated by similarity evaluation and cluster analysis.The 18 common peaks were confirmed. The similarity of F. suspensa from different habitats was more than 0. 98,and 56 chemical constituents were identified. Different processing methods had great influence on the quality of F. suspensa. Compared with boiled and direct drying,the quality of F. suspensa processed by sun-drying was obviously decreased. The similarity was about 0. 58. Different specifications of F. suspensa also had obvious distinction,and the similarity was about 0. 78. The effective components of grown F. suspensa,such as forsythoside A and phillyrin,were significantly reduced. The results of cluster analysis were basically consistent with the results of similarity evaluation. The establishment of fingerprint and the recognition of chemical pattern of F. suspensa can provide a more comprehensive reference for the quality control of herbs.

Progress in epigenetic study of clear cell renal cell carcinoma / 中国病理生理杂志

The epigenetic changes of clear cell renal cell carcinoma(ccRCC )are considered to be the main molecular mechanisms of its pathogenesis ,including DNA methylation ,histone modification ,microRNA change ,and so on.DNA methyltransferases(DNMTs)catalyze the occurrence of DNA methylation.DNA methylation changes are mani-fested in the overall low methylation of the genome and the high methylation of specific sites ,which were involved in the de-velopment of ccRCC by affecting the expression of tumor suppressor genes.Due to histone-modified enzyme involvement ,histone modification is shown as possible genetic reversal.MicroRNA plays an important role in the abnormal expression of ccRCC genes.With the studies of epigenetic mechanism and molecular pathology ,it is important to explore the mechanisms and to seek effective early diagnosis ,treatment and prognosis intervention of ccRCC.

Meta-analysis on the Safety and Efficacy of Absorb Bioresorbable Vascular Scaffold Versus Everolimus Eluting Stent for Percutaneous Coronary Intervention / 中国循环杂志

Objectives:To systemically review the safety and efficacy of bioresorbable vascular scaffold (BVS) versus everolimus eluting stent (EES) for percutaneous coronary intervention (PCI). Methods:The database searched includes PubMed, Medline, MEDILINE, EMBASE, Cochrane library, CNKI and Wanfang. Database retrieval time was between database establishment time to October 2017. During the same time, authors accessed the conference summary and related websites to collect published randomized controlled trials of published data. To evaluate the quality of the literature according to the modified Jadad scale and extracted the data. Meta-analysis was performed using Review Manager 5.3 software. Results:Nine trials were included; 6 721 patients were randomized to receive BVS (n=3 670) or EES (n=3 051). Time of follow-up was ranged from 6 to 36 months. Compared with metallic EES, risk of target lesion failure (RR=1.31, 95%CI:1.08-1.58; P=0.005) and in-stent thrombosis (RR=2.89, 95%CI:1.85-4.53; P＜0.0001), ischemia-driven target lesion revascularization (RR=1.44,95%CI:1.12-1.86, P=0.005)、target-vessel myocardial infarction (RR=1.74, 95%CI:1.33-2.27, P＜0.0001) and all myocardial infarction (RR=1.49, 95%CI:1.16-1.91, P=0.002) were all significantly higher in BVS group than in EES group. There were no significant differences in all-cause death (RR=0.87, 95 % CI:0.57-1.33, P=0.520), cardiovascular mortality (RR=0.78, 95%CI:0.54-1.11, P=0.160) and composite endpoints (RR=1.10, 95%CI:0.95-1.27, P=0.210) between the two groups. Conclusions:Compared with metallic EES, the BVS appears to be associated with both lower efficacy and higher thrombotic risk during the observation period.

Preparation and identification of a monoclonal antibody against Mycoplasma hyorhinis / 中国人兽共患病学报

The aim of this study was to produce a monoclonal antibody against Mycoplasma hyorhinis,which would be useful in the diagnosis and pathogenesis researches of M.hyorhinis.BALB/c mice were immunized with whole cell protein of M.hyorhinis,and then the monoclonal antibody (McAb) was prepared by hybridoma technique.The isotype of the McAb was identified,and then the titer and specificity were analyzed.The prepared McAb was used to detect M.hyorhinis in the colony immunoboltting assay and indirect immunofluorescence assay.A hybridoma cell line was obtained,and was named Mhr-08.The McAb belonged to IgG1 isotype,and the light chain was κ type.The titer was detected to be 1 ∶ 102 400 by ELISA.The result of Western-blot indicated that this McAb strongly reacted to a 43 kDa protein of M.hyorhinis,without cross-reaction with other swine mycoplasmas,Escherichia coli or KM2 medium.It revealed that the McAb recognized a surface membrane protein and was successfully applied to detect M.hyorhinis in colony immunoboltting assay.The mycoplasmas bound to the tracheal epithelial cells was successfully detected by using this McAb in indirect immunofluorescence assay.In conclusion,a McAb against M.hyorhinis was successfully prepared,which provides as a useful tool for the diagnosis and pathogenesis researches.

Specific sIgA antibodies against swine influenza virus H3N2 infection / 中国人兽共患病学报

To study different breed pigs reply the swine flu virus infections,specific antibody of sIgA secretion regularity of respiratory tract and the differences of sIgA antibody according to different antigen proteins were detected.A/swine/Nanjing/ 51/2010(H3N2) was intranasally infected pigs (1 × 107 TCID50/mL and 2 mL/pig),and then the nasal swab samples were collected at different time points within 21 days after infection.M1,NS1 and PB1 recombinant protein,respectively,were used to establish indirect ELISA method for detecting specific antibody of sIgA,and to analyze its secretion regularity.Results displayed that there was no significant difference among three kinds of recombinant protein in the whole test,characterizing by specificity sIgA antibody levels rising rapidly after 5 infection days and reaching peak at day 14,then began to decline.Among different varieties of pigs,sIgA antibody production of PB1 protein in Obama group was significantly higher than that in binary pigs at 14th and 21st day (P＜0.05).It had no significant difference between M1 group and the NS1 group (P＞0.05).This experiment preliminary explores the secretion regularity of specificity sIgA antibody after infected swine flu virus,which laid a foundation for further study of SIV mucosal antibody diagnostic reagents.

The role of hamartin in ischemia/hypoxia tolerance / 中国比较医学杂志

Hypoxia/ischemia is a common clinical pathophysiological process and cause of death,and it is a common problem in extreme conditions such as high altitude,astronautics and diving.Hamartin is a kind of effective endogenous neuroprotectant and could increase cell tolerance to acute hypoxia or ischemia, thus,is of significance to research.The role of hamartin in hypoxia/ischemia has been a research focus of many scientists.Elucidating the related protective effect and its DNA methylation on hypoxia/ischemia can not only reduce injury,but also lay a basic for further studying the role of hamartin and its DNA methylation in other pathophysiological processes and provide theoretical guidance for the following clinical study.In this paper,we review the structure,mechanism and role of hamartin and the effect of its DNA methylation on hypoxia/ischemia.

Embryonic natural orifice transluminal endoscopic surgery in the treatment of severe acute pancreatitis complicated by abdominal compartment syndrome / 世界急诊医学杂志（英文）

@#BACKGROUND: The study aimed to estimate the value of embryonal natural orifice transluminal endoscopic surgery (ENOTES) in treating severe acute pancreatitis (SAP) complicated with abdominal compartment syndrome (ACS). METHODS: The patients, who were randomized into an ENOTES group and an operative group, underwent ENOTES and laparotomy, respectively. The results and complications of the two groups were compared. RESULTS: Enterocinesia was observed earlier in the ENOTES group than in the operative group. Acute Physiology and Chronic Health Evaluation II (APACHE II) score of patients in the ENOTES group was lower than that of the operative group on the 1st, 3rd and 5th post-operative day (P<0.05). The cure rate was 96.87％ in the ENOTES group, which was statistically different from 78.12％ in the operative group (P<0.05). There were significant differences in complications and mortality between the two groups (P<0.01). CONCLUSION: Compared with surgical decompression, ENOTES associated with flexible endoscope therapy is an effective and minimal invasive procedure with less complications.

Simultaneous determination of seven components in Pudilan Xiaoyan oral liquid by HPLC / 中国中药杂志

<p><b>OBJECTIVE</b>To establish an HPLC method for the content determination of baicalin, wogonin, chlorogenic acid, caffeic acid, cichoric acid, corynoline and adenosine in Pudilan Xiaoyan oral liquid.</p><p><b>METHOD</b>The analysis was performed on a Phenomenex Luna C18 column (4.6 mm x 250 mm, 5 µm) with a gradient mobile phase of methanol-0.1% trifluoroacetic acid solution system at flow rate of 1.0 mL · min(-1). The detective wavelength was at 280 nm. The column temperature was 30 °C.</p><p><b>RESULT</b>The standard curves of seven studied components show good linearity in their concentration ranges with r ≥ 0.999 6. The average recovery was 98.73%-102.1% with RSD less than 2.6%.</p><p><b>CONCLUSION</b>The method is rapid, simple and accurate, and can be applied for the quality control of Pudilan Xiaoyan oral liquid.</p>

Effect of Qiling Decoction combined HAART on expression levels of Treg cells and Th17 in HIV/AIDS patients / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the effect of Qiling Decoction (QD) combined highly active antiretroviral treatment (HAART) on expression levels of peripheral blood Th17 and Treg cells in HIV/AIDS patients.</p><p><b>METHODS</b>Totally 55 HIV/AIDS patients were randomly assigned to the treatment group (28 cases) and the combination group (27 cases). Besides, 21 HIV negative patients were recruited as the healthy control group. Those in the treatment group received HARRT alone, while those in the combination group received HAART combined QD. The observation lasted for 24 weeks. Meanwhile, according to peripheral blood CD4+ T cell counts before treatment, HIV/AIDS patients were assigned to three subgroups. For patients in subgroup 1, 1 cells/microL < CD4+ T cell counts < or = 100 cells/microL; For patients in subgroup 2, 101 cells/microL < CD4+ T cell counts < or = 200 cells/lL; For patients in subgroup 3, 201 cells/microL < CD4+ T cell counts < or = 350 cells/microL. Expression of peripheral blood Th17 and Treg cells, and number of CD4+ T cell counts were detected using flow cytometry (FCM)in HIV/AIDS patients at the pre-treatment baseline, week 4, 12, and 24, as well as those in the healthy control group.</p><p><b>RESULTS</b>Compared with the healthy control group, CD4+ T cell counts and the baseline expression level of Th17 cells in the peripheral blood of HIV/AIDS patients significantly decreased, the expression level of Treg cells significantly increased P < 0.01). Compared with before treatment in the same group, CD4+ T cell counts all increased at week 4, 12, and 24 in the two treatment groups, showing statistical difference (P < 0.05, P < 0.01). There was no statistical difference in the effective rate at various CD4+ T cell levels between the two groups (P > 0.05). There was no statistical difference in expression levels of Th17 and Treg cells between the combination group and the treatment group at any time point (all P >0.05). The Th17/Treg ration significantly increased in the combination group after 24 weeks of treatment, showing statistical difference when compared with the treatment group (U = 2.135, P = 0.038).</p><p><b>CONCLUSION</b>QD could improve the immune balance of Th17/Treg cells, which might be one of its mechanisms for improving HIV/AIDS patients' immunity.</p>

Effect of overexpression of DNA methyltransferase 3B4 gene on proliferation of 293A cells / 中国癌症杂志

Background and purpose:DNMT3B has nearly 40 known splice variants expressed in a tissue-and disease-speciifc manner, but the roles of these splice variants in the cell are still unclear. The aim of this study was to investigate the effects of overexpression of DNA methyltransferase 3B4 (DNMT3B4) gene on proliferation of human embryo kidney 293A cells. Methods:293A cells were transfected with plasmid pCMV-DNMT3B4 or pCMV-2B and then treated with G418 to get the stable cell line. The stable cell lines were determined for proliferation level by MTT method, and for cell cycle distribution by lfow cytometry. The expression of p21 was detected by real-time PCR and Western blot. The methylation status of p21 gene promoter was detected by methylation-speciifc PCR (MS-PCR). Results:The absorbance value in DNMT3B4-1 and DNMT3B4-2 clone were (58.92±3.47)%and (68.82±5.64)%as compared to 293A-vector cells using MTT method. DNMT3B4 overexpression signiifcantly decreased cell proliferation (P<0.05). S phase fraction of 293A-vector cells was (40.44±0.91)%. While in DNMT3B4-1 and DNMT3B4-2 clone cells, the S phase fraction was (35.88±2.00)%and (37.00±1.79)%respectively. Overexpression of DNMT3B4 could significantly decrease S phase fraction (P<0.05). The expression of p21 in DNMT3B4 overexpressed cells was increased, but the methylation status of p21 gene promoter was unchanged.Conclusion:Overexpression of DNMT3B4 can inhibit 293A cell proliferation and can facilitate p21 expression.

Hypoxic preconditioning: effect, mechanism and clinical implication (Part 1) / 中国应用生理学杂志

Hypoxic preconditioning (HPC) refers to exposure of organisms, systems, organs, tissues or cells to moderate hypoxia/ischemia that is able to result in a resistance to subsequent severe hypoxia/ischemia in tissues and cells. The effects exerted by HPC are well documented. The original local in situ (LiHPC) is now broadened to remote ectopic organs-tissues (ReHPC) and extended crossly to cross pluripotential HPC(CpHPC) induced by a variety of stresses other than hypoxia/ischemia, including cancer, for example. We developed a unique animal model of repetitive autohypoxia in adult mice, and studied systematically on the effects and mechanisms of HPC on the model in our laboratory since the early 1960s. The tolerances to hypoxia and protection from injury increased significantly in this model. The adult mice behave like hypoxia-intolerant mammalian newborns and hypoxia-tolerant adult animals during their exposure to repetitive autohypoxia. The overall energy supply and demand decreased, the microorganization of the brain maintained and the spacial learning and memory ability improved but not impaired, the detrimental neurochemicals such as free radicals down-regulated and the beneficial neurochemicals such as adenosine(ADO) and antihypoxic gene(s)/factor(s) (AHGs/AHFs) up-regulated. Accordingly, we hypothesize that mechanisms for the tolerance/protective effects of HPC are fundamentally depending on energy saving and brain plasticity in particular. It is thought that these two major mechanisms are triggered by exposure to hypoxia/ischemia via oxygen sensing-transduction pathways and HIF-1 initiation cascades. We suggest that HPC is an intrinsic mechanism developed in biological evolution and is a novel potential strategy for fighting against hypoxia-ischemia and other stresses. Motivation of endogenous antihypoxic potential, activation of oxygen sensing--signal transduction systems and supplement of exogenous antihypoxic substances as well as development of HPC appliances and HPC medicines such as AHFs are encouraged based on our basic research on HPC. HPC may result in therapeutic augmentation of the endogenous cytoprotection in hypoxic-ischemic or suffering from other diseases' patients. Evolutionary consideration of HPC and clinical implications of HPC are both discussed to guide future research. The product of AHF is expected to be one of the most effective first aid medicines to rescue patients in critical condition. HPC is beginning to be used in surgery and is expected to be developed into a feasible adaptive medicine in the near future.

Role of protein kinase C in the mechanism of central sensitization of migraine / 中华神经医学杂志

Objective To explore the role of protein kinase C (PKC) in the mechanism of central sensitization of migraine.Methods Sixty healthy adult male SD rats,weighting from 200 to 250 g,were randomly divided into five groups:normal group,sham-operated group,migraine model group,chloroform treatment group and H-7 (the inhibitor of PKC) treatment group (n=12).Dural blood flow monitor was performed by laser Doppler blood flow imager and extracellular discharge frequency in the spinal trigeminal nucleus was observed by multi-conductive polygraph; the dural blood flow and discharge frequency changes were analyzed and compared.Results Two hours after the success of model making,the dural blood flow in the migraine model group increased obviously as compared with that in the sham-operated group (P＜0.05); as compared with that in the migraine model group,the dural blood flow in the H-7 treatment group decreased obviously (P＜0.05); as compared with sham operation group,blood flow decreased obviously in H-7 group (P＜0.05).Extracellular discharge frequency in the spinal trigeminal nucleus increased 2 h after the success of model making; 2 hours after model making,the extracellular discharge frequency was (323.82±11.00) ％ of baseline level; as compared with that in the migraine model group,discharge frequency in the H-7 treatment group decreased obviously (P＜0.05); as compared with that in the sham-operated group,discharge frequency in the H-7 treatment group had no obvious changes (P＞0.05).Conclusion PKC may play an important role in the mechanism of central sensitization of migraine.