BACKGROUND:Although several prosthetic methods, such as artificial denture and dental implants, are clinical therapies to tooth loss, they are thought to have safety and usage time issues. With the development of biological and biomaterial sciences, recently, tooth tissue engineering has attracted more and more attention.
OBJECTIVE:To reflect advances and problems of tissue engineering technologies for promotion of tooth regeneration.
METHODS:Using the keywords of“tissue engineering, tooth regeneration”in English and Chinese, PubMed and CNKI databases from 2007 to 2013 were retrieved. A total of 65 literatures addressing tooth regeneration and tissue engineering were col ected, including 25 Chinese articles and 40 English articles. Published early, repetitive, and similar researches were excluded. Final y, 48 articles were included.
RESULTS AND CONCLUSION:The combination of stem cells and suitable scaffolds is widely used in tooth regeneration today, and growth factors or bone marrow which can produce promote tooth regeneration are added as wel , which has achieved partial or whole tooth regeneration. But there are apparent deficiencies in studies which focus on mechanisms behind tooth regeneration.

[ ABSTRACT] AIM: To investigate the underlying mechanisms responsible for endothelial dysfunction of type 1 diabetes mellitus (DM) rats fed with high-salt diet.METHODS:Type 1 DM was induced by intraperitoneal injection of streptozotocin (70 mg/kg).Normal and diabetic rats were fed high-salt food (HS, 8% NaCl) and standard food for 6 weeks, respectively.Isometric tension of the mesenteric arteries were measured .The expression of Akt , endothelial nitric oxide synthase (eNOS) and caveolin-1 (Cav-1) was examined by Western blot .RESULTS:The rats in DM+HS group exhibited more pronounced impairment of vasorelaxation to acetylcholine and insulin compared with either DM group or HS group (P<0.01).Akt and eNOS phosphorylation levels, and nitric oxide (NO) concentration in DM +HS group were significantly lower than those in DM group (P<0.01).The level of Cav-1 in DM+HS group was significantly higher than that in DM group and HS group .CONCLUSION:Impaired endothelial Akt activation , increased Cav-1 expression and re-sultant decreased eNOS activation contribute to aggravate high-salt diet-induced endothelial dysfunction and hypertension in DM rats.

Objective To study the tumor targeting ability and application of farnesylthiosalicylic Acid (FTS) and heptamethine carbocyanine fluorescent dye-mediated near-infrared imagine in living animals, and confirm the inhibitory effect of this compound on growth of tumor cells.Methods Human breast cancer cell line MCF-7, glioma cell line U251 and prostate cancer cell line PC3 were cultured to logarithmic growth phase, and different concentrations of FTS and FTS-IR783 were added, respectively.We observed the inhibitory effect of those two compounds on the growth of tumor cells.Under fluorescence microscopy, specific accumulation of FTS-IR783 in these tumor cells was observed.The tumor cells (1×106) were transplanted subcutaneously into nude mice.These mice were subjected to intraperitoneal injection of FTS-IR783 (10 nmol/mouse) two weeks later.In the in vivo imaging, near infrared fluorescence signal and tumor volume were measured and their correlation was analyzed.Results Compared with FTS, FTS-IR783 significantly inhibited the growth of MCF-7, U251 and PC3 cells in vitro.FTS-IR783 was specifically uptaken by these three kinds of tumor cells, showing strong near infrared fluorescence in cell agglomerates.After subcutaneous injection of FTS-IR783, the correlation between fluorescence intensity and tumor volume was 0.987, 0.998 and 0.971, respectively.Conclusions The compound of FTS conjugated with near infrared fluorescent dye IR-783 can specifically recognize tumor cells, in both in vitro and in vivo imaging.At the same time, the compound can significantly inhibit the growth of tumor cells, and may be expected to become a new potential targeted drug.

AIM:To explore the influence of exogenous hydrogen sulfide ( H2 S) on coagulation and fibrinoly-sis in ferric chloride ( FeCl3 )-induced mouse carotid artery thrombosis .METHODS: The mice were divided into sham control group, model group, different concentrations (12.5, 25 and 50μmol/kg) of sodium hydrosulfide (NaHS, H2S do-nor) groups and 30 mg/kg clopidogrel ( positive control ) group.Intraperitoneal injection of NaHS at different concentra-tions and oral administration of clopidogrel bisulfate were performed for 3 d prior to FeCl 3-induced carotid artery thrombo-sis.The frozen sections of the carotid artery were collected to perform HE staining , and the thrombus pattern and the chan-ges of vascular pathology were observed .The thrombus was weighed to calculate thrombosis inhibitory rate .Prothrombin time ( PT) , activated partial thromboplastin time ( APTT) , fibrinogen ( FIB) and fibrinogen degradation product ( FDP) in the mice were also measured by a coagulometer .The plasma levels of thromboxane B 2 ( TXB2 ) , 6-keto-prostaglandin F 1α(6-keto-PGF1α) and plasminogen activator inhibitor (PAI) were detected by ELISA.RESULTS: Compared with model group, NaHS dose-dependently inhibited the formation of carotid artery thrombus .NaHS treatment reduced the contents of TXB2 and PAI, and recovered 6-keto-PGF1αcontent in thrombosis model group .In NaHS treatment groups , 6-keto-PGF1α/TXB2 and thrombus weight was negatively correlated .NaHS treatment prolonged PT and APTT , reduced the content of FIB, but increased the level of FDP in thrombosis model group .CONCLUSION:Hydrogen sulfide prevents FeCl 3-induced carotid artery thrombosis by inhibiting coagulation and activating fibrinolysis .

PURPOSE: Elevation in serum alanine aminotransferase (ALT) levels is a biomarker for metabolic syndrome (MS); however, the relationship has not been fully investigated within the reference interval of ALT levels. Our objective was to explore the relationship between serum ALT levels within the reference interval and MS in Chinese adults. MATERIALS AND METHODS: This cross-sectional study included 16028 adults, who attended routine health check-ups at Shengli Oilfield Central Hospital from January 2006 to March 2012. The reference interval of serum ALT level was defined as less than 40 U/L. Logistic regression models and restricted cubic spline were used to evaluate the association of ALT with MS. RESULTS: The prevalence of MS in the total population was 13.7% (6.4% for females and 18.4% for males). Multiple logistic regression showed that ALT levels were positively associated with MS after adjustment for potential confounding factors. The odds ratio of MS in the top quartile was 4.830 [95% confidence interval (CI): 2.980–7.829] in females and 3.168 (95% CI: 2.649–3.790) in males, compared with the ALT levels in the bottom quartile. The restricted cubic spline models revealed a positive non-linear dose-response relationship between ALT levels and the risk of MS in women (p for nonlinearity was 0.0327), but a positive linear dose-response relationship in men (p for nonlinearity was 0.0659). CONCLUSION: Serum ALT levels within the reference interval are positively associated with MS in a dose-response manner. Elevated ALT levels, even within the reference interval, may reflect early dysmetabolic changes.
Adult ; Aged ; Alanine Transaminase/*blood ; Asian Continental Ancestry Group ; Biomarkers/blood ; Confidence Intervals ; Cross-Sectional Studies ; Dose-Response Relationship, Drug ; Female ; Humans ; Logistic Models ; Male ; Metabolic Syndrome X/*enzymology/epidemiology ; Middle Aged ; Odds Ratio ; Prevalence ; Reference Values

Objective:To explore the prognostic value of quantitative plaque analysis and coronary CT angiography (CCTA) derived fractional flow reserve (CT-FFR) in evaluating plaque progression (PP).Methods:A total of 118 consecutive patients who underwent serial CCTA examinations in Affiliated Hospital of Jiangnan University from December 2013 to December 2017 were retrospectively enrolled. There were 37 patients in the PP group and 81 patients in the non-PP group. All patients′ CCTA images were quantitatively analyzed using plaque analysis software. The quantitative analysis parameters included stenosis degree, plaque length, total plaque volume, calcified plaque volume, non-calcified plaque volume, minimum lumen area, remodeling index(RI) and plaque burden. Plaque progression was defined as plaque burden change rate>1%. CT-FFR analysis was performed using cFFR software and the CT-FFR value was measured at 2-4 cm distal to the coronary lesion. Baseline parameters between the two groups were evaluated using Students t-test, U-test, chi-square test. The logistic regression model was conducted to evaluate the relationship between CCTA derived parameters and PP. Receiver operating characteristic curve analysis with the areas under the curve (AUC) was used to determine the predictive performance of different CCTA parameters. Results:Compared with the non-PP group, the patients were older( t=2.391, P=0.018), the prevalence of hyperlipidemia was higher(χ2=4.550, P=0.033), and the proportion of statins use was lower (χ2=4.764, P=0.029) in the PP group. The PP group showed greater coronary stenosis, smaller minimum lumen area, larger plaque volume and non-calcified plaque volume, larger remodeling index and lower CT-FFR value on baseline CCTA (all P<0.05). Logistic regression analysis demonstrated that RI(OR=2.714, 95%CI:1.078-6.836)and CT-FFR (OR=2.940, 95%CI:1.215-7.116) were independent predictors of PP. The model based on CCTA stenosis degree, quantitative plaque features and CT-FFR (AUC 0.83, 95%CI: 0.75-0.90; P<0.001) was significantly better than the model based on CCTA stenosis degree (AUC 0.62, 95%CI: 0.52-0.70, P=0.049) and the model based on CCTA stenosis degree and quantitative plaque characteristics (AUC 0.77, 95%CI: 0.68-0.84, P<0.001). Conclusions:Compared with the prediction model derived on stenosis degree, plaque quantitative markers and CT-FFR can improve the prediction value of PP.RI and CT-FFR were important predictors of PP.

OBJECTIVE: To assess the value of single sperm sequencing in preimplantation genetic testing for monogenic disease (PGT-M). METHODS: A Chinese couple with two children whom had died of Spinal muscular atrophy (SMA) and attended the Jiangxi Provincial Maternal and Child Health Care Hospital in June 2020 was selected as the subject. Eleven single sperm samples were isolated by mechanical immobilization and subjected to whole genome amplification. Real-time PCR and Sanger sequencing were used to detect the SMN1 variants in the single sperm samples. Genomic DNA of the wife, her parents and the husband, as well as one single sperm sample harboring the SMN1 variant and two single sperm samples without the variant were used for the linkage analysis. Targeted capture and high-throughput sequencing were carried out to test 100 single nucleotide polymorphisms distributed within 2 Mb up- and downstream the variant site. The haplotypes linked with the SMN1 variants were determined by linkage analysis. Blastocyst embryos were harvested after fertilizing by intracytoplasmic sperm injection. Cells from the trophoblasts of each embryo were biopsied and subjected to whole genome amplification and targeted capture and high-throughput sequencing to determine their carrier status. Chromosomal aneuploidy of wild-type embryos was excluded. An euploid embryo of high quality was transferred. Amniotic fluid sample was taken at 18 weeks of gestation to confirm the status of the fetus. RESULTS: Genetic testing showed that the couple both had deletion of exons 7 ~ 8 of the SMN1 gene. The wife has inherited the deletion from her father, while the husband was de novo. The haplotypes of the husband were successfully constructed by single sperm sequencing. Preimplantation genetic testing has indicated that 5 embryos had harbored the heterozygous variant, 4 embryos were of the wild type, among which 3 were euploid. Prenatal diagnosis during the second trimester of pregnancy has confirmed that the fetus did not carry the deletion. CONCLUSION By single sperm sequencing and PGT-M, the birth of further affected child has been successfully avoided.
Humans ; Pregnancy ; Female ; Child ; Male ; Preimplantation Diagnosis ; East Asian People ; Semen ; Genetic Testing ; Muscular Atrophy, Spinal/genetics* ; Aneuploidy ; Blastocyst/pathology* ; High-Throughput Nucleotide Sequencing ; Spermatozoa

Objective:To analyze, with Wuhan as an example, the problems found in the infrastructure development of China′s healthcare institutions, and put forward optimization suggestions for future epidemic prevention and control.Methods:From May to June 2020, we surveyed with questionnaires 56 healthcare institutions in Wuhan, covering such aspects as basic information of the institutions, infectious disease infrastructure readiness, and the converted wards for COVID-19. Statistical descriptions were used to analyze data so acquired.Results:The number of beds in the infectious departments of healthcare institutions in Wuhan amounted to 1.64 per 10 000 people, yet the existing 1 873 beds and about 5 000 convertible beds failed to meet the medical needs against the outbreak of COVID-19. After the outbreak, a total of 19 084 convertible beds were set up, of which general hospitals accounted for 88%; the area occupied by each converted bed in traditional Chinese medicine hospitals, hospitals of traditional and Western medicine, and maternal and child hospitals (<30.0m 2) was lower than that in general hospitals and specialist hospitals (>40.0m 2). Conclusions:Healthcare institutions should scientifically allocate " peacetime-wartime adaptive" hospital beds, optimize both the number and efficiency of these beds, and prepare for the worst scenarios, so that the infrastructure can be built and maintained in strict accordance with standards, government departments can rationally arrange infectious disease prevention and control facilities and strengthen their planning in case of emergencies.

OBJECTIVE To investigate in vitro activities of 12 antimicrobial agents including cefmetazole against extended-spectrum beta-lactamases-producing Escherichia coli(528 strains),Klebsiella pneumoniae(311 strains) and Proteus mirabilis(15 strains).METHODS They all collected from 15 teaching hospitals in China during 2005 and 2006 and included in the study.The levels of minimal inhibitory concentration(MIC) of 12 antimicrobial agents were determined by agar dilution method.WHONET 5.4 Software was used to analyze the data.RESULTS Against ESBLs-producing E.coli and ESBLs-producing K.pneumoniae,carbapenems were the most active antimicrobial agents(all 100.0% susceptible),followed by cephamycins(80.1-97.3%).Piperacillin/tazobactam(78.5-95.1%)showed a higher activity than cefoperazone/sulbactam(44.1-56.2%).The susceptible rate to ceftazidime against ESBLs-producing E.coli was remarkably higher than the other three cephalosporins,however the differences did not happen to ESBL-producing K.pneumoniae obviously.The susceptible rate to cefuroxime was below 1.6%.ESBLs-producing K.pneumoniae showed high sensitivity to carbapenems,cephamycins and ?-lactam/lactamase inhibitor combinations(all 100% susceptible),however the susceptible rates to cephalosporins were relatively lower.CONCLUSIONS Carbapenems and cephamycins remain the relatively high activity against ESBLs-producing Enterobacteriaceae.

Objective To investigate antimicrobial resistance among Streptococcus pneumoniae clinically isolated from 14 teaching hospitals located at different areas in China in 2005-2008 and to give logical guidance for clinical empirical therapy.Methods A total of 1 317 non-repetitive S.pneumoniae isolates in 14 teaching hospitals from 2005-2008 were collected and sent to the central lab for reidentification and susceptibility testing, including 271 isolates collected in 2005, 391 isolates collected in 2006, 363 isolates collected in 2007 and 292 isolates collected in 2008. Most of the isolates were from community-acquired respiratory tract infections, which were isolated from outpatient or emergency department patients with respiratory tract infections or those patients with respiratory tract infections within ≤48 hours hospitalization.The districts where the organisms were isolated include North China, Northeast China, South China, Central and Northwest China and East China.The patients included adults, teenagers and children.The minimum inhibitory concentrations (MICs) or inhibitory zone diameter of 17 antimicrobial agents were determined by Etest method, agar dilution method or disk diffusion method.WHONET5.5 software was used to analyze susceptibility rate, intermediate rate, resistance rate, MIC50 and MIC90.Results Linezolid (100%) and fluoroquinolones (95.2%-99.7%) showed excellent activities against S.pneumoniae.Among β-lactams, amoxicillin-clavulanic acid remained high activities (73.8%-92.1%),followed by penicillin, ceftriaxone and cefepime with year-over-year decrease in activities.The activities of three second-generation cephalosporins were low (36.3%-38.4% in 2008).The activities of erythromycin, azithromycin, clindamycin, trimethoprim/sulfamethoxazole and tetracycline against S.pneumoniae were poor and decreased year over year.The incidence of penicillin non-susceptible S.pneumoniae (PNSP) was increasing especially for PISP (from 4.4% in 2005 to 20.2% in 2008).The incidence of PNSP in North China was low (6.0%), while this value were high in central China and East China (30.1% and 38.7%, separately).The incidence of PNSP in adults (15.7%) was obviously lower than that in children(≤5 years:33.0%) and teenagers (6-17 years:38.2%).Conclusions linezolid and fluoroquinolones showed excellent in vitro activity against S.pneumoniae, followed by penicillin and cephalosporins with year-over-year decrease of activity. Clinicians should pay more attention when using those antimicrobial agents with poor activity against S.pneumoniae, which include macrolides, clindamycin, trimethoprim/sulfamethoxazole and tetracycline.