Hepatic oval cells (OCs) are the stem cells of the liver. They can differentiate into liver cells, bile duct epithelial cells and other cells, and also are closely related to liver regeneration and liver diseases. In this article, we give a brief summary focused on the source, location, proliferation, differentiation, apoptosis, transplantation of hepatic oval cells, and its role in liver regeneration and liver diseases.

Objective To investigate the influence of serial subcultivation on the immunoregulation of retinal pigment epithelialium cells in vitro.Methods Co-culture-systems of HRPE cells with lymphocytes were established in vitro.The expression of Fas on different passages of HRPE cells and the induction of apoptosis on lymphocytes were observed by flow cytometry. Results When co-cultured with lymphocytes,the expression of Fas was tapering and the duration of culture in vitro was significantly correlated with the expression of Fas(the rate of positive cell: r=-0.859,P0.05).Conclusion HRPE cells beyond 3 passages showed a 1ow capability of immunoregulation and were not suitable for seeds cells for HRPE transplantation.

Objective To compare the clinical effect of UK and rt-PA intravenous thrombolytic therapy for acute myocardial infarction.Methods By SAS statistical analysis system,72 patients with acute myocardial infarction were randomly divided into rt-PA group and UK group,each group had 36 cases.The coronary artery recanalization rate,bleeding events,adverse cardiovascular events,mortality,and cardiac troponin T(cTnT) level were recorded.Results In rt-PA group,0.5h,1 h,2h after the start of thrombolytic therapy,the coronary artery recanalization rate was significantly higher than that in the control group,the difference was statistically significant (x2 =7.32,6.12,5.81,all P ＜ 0.05).In rt-PA group,3 cases had bleeding events,2 cases died,and in UK group,5 cases had bleeding events,3 cases died,,there was no statistically significant difference between the two groups (x2 =1.22,P ＞ 0.05).In rt-PA group,there were 6 cases with adverse cardiovascular events,14 cases in the control group,the difference was statistically significant (x2 =4.56,P＜0.05).2 cases died in rt-PA group,3 cases died in UK group,the mortality between the two groups had no statistically significant difference (P ＞ 0.05).The cTnT level in the hospital 6h,12h was significantly higher than admission in two groups (t =6.67,6.30,4.11,4.22,4.40,all P ＜ 0.05).In rt-PA group,cTnT level in the hospital 6h,12h was significantly lower than that in UK group (t =5.92,6.61,all P ＜0.05).Conclusion Compared with UK,rt-PA in the treatment of acute myocardial infarction can increase recanalization rate,decrease adverse events and myocardial injury,it is worthy of clinical application.

Face to various disaster and dilemma, the tasks of national rescue team were fast and effective rescue, and reducing the harm of life and damage of property, and decreasing each damage to the lowest point. The ability of national rescue team could reflect the strength and developed degree of a national, it further more manifested the levels of medical rescue team. Face to major disasters, it was vital to provide humanitarian assistance for the affected people in disaster areas at the first time. Many developed countries have established national rescue teams and equipped various kinds of rescue equipment, and the disaster relief of medical team was regarded as the main force in emergency health rescue for disaster. refer to the constitution and equipment of national rescue team of developed countries has an important guiding role for perfection of emergency medical rescue in China.

Family with sequence similarity 20,member C(FAM20C),also known as dentin matrix protein 4 (DMP4),is a calcium-binding kinase for secreted phosphoproteins,and is highly expressed in mineralized tissues,which phosphorylates secretory calcium-binding phosphoproteins (SCPPs),thus modulating biomineralization.Mutations in FAM20C may cause the Raine syndrome,an autosomal recessive disorder characterized by generalized osteosclerosis with teeth defects,bone defects,hypophosphatemia and neonatal lethality.FAM20C plays an important role in the osteogenesis and odontogenesis through regulating the differentiation of osteoblast,ameloblast and odontoblast,as well as suppressing the production of phosphate-regulating hormone fibroblast growth factor 23 (FGF23).The research progress on the function of FAM20C in osteogenesis and odontogenesis is reviewed.

Early diagnosis and early thrombolysis may have a better prognosis in patients with ischemic stroke.The benefits from the development of modem magnetic resonance imaging techniques in this field have received great attention,and it directly guides the 'management of the acute ischemic stroke,This article briefly reviews diffusion-weighted imaging,perfusion- weighted imaging and MR spectroscopy analysis that are more commonly used in current clini- cal practice.

Child ; Humans ; Inflammatory Bowel Diseases ; diagnosis

Objective To establish a method to quantitatively assess melanosome transfer with incorporation of 14C-thiouracil (TU) into nascent melanin. Methods To characterize whether 14C-TU was exclusively incorporated into melanin-producing cells, the same number of mouse melan-a or SP-1 keratinocytes were labeled with 14C-TU for 12 hours and 48 hours, respectively, followed by the measurement of radioactivity. Mouse melan-a melanocytes were pre-labeled with 1 Ci/mL 14C-TU, and cocultured with mouse SP1 keratinocytes to develop an assay system for melanosome transfer to keratinocytes. Following co-culture, the keratinocytes with transferred radioactivity were separated from melanocytes at different time points via two times of differential trypsinization. Transferred radioactivity in keratinocytes, denoting the amount of melanosome transfer, was measured with liquid scintillation counting. Meanwhile, the effects of forskolin, a PKA activator, and nicotinamide on melanosome transfer were also investigated with this assay system.Results The incorporated radioactivity in melan-a cells was 66- or 80-fold as high as that in SP-1 cells,indicating that 14C-TU would be a suitable tracer for melanosome transfer in co-culture with keratinocytes. A purity of 84.5% was achieved for keratinocytes with transferred radioactivity by twice differential trypsinization.As shown by this assay, there was an approximately 0.67-fold decrease in melanosome transfer with the treatment of 1 g/L nicotinamide and 2.3-fold increase with 20μmol/L forskolin treatment. After coculture with SP1 cells for 8-12 hours, melan-a cells developed well-extending dendrites with detectable melanosome transfer, while no proliferation of melan-a cells induced by forskolin was seen. Conclusion An optimized protocol for selective incorporation of 14C-TU into nascent melanin has been successfully applied to the quantitative measurement of melanosome transfer from melanocytes to keratinocytes induced by forskolin or nicotinamide.

Objective:To analyze the failure factors in root canal therapy(RCT)by analysis of the failed cases.Methods:215 teeth of 206 patients were analyzed according to former treatment records,clinical examination,pretreatment radiographs,and root canal exploration during endodontic retreatment.Results:67.9% of failed teeth showed apical radiolucency,12.6% showed under-filled canal material without apical radiolucent area,and 8.4% involved coronal leakage.When examined with X ray,84.2% of teeth indicated under-filling,and most canals of premolars and molars had poor taper.Most missed root canals were found in maxillary first molars and premolars.18.1% of teeth had complications such as ledge and apical transportation.Conclusions:The factors associated with RCT failure involve cleaning,obturation and poor seal of root canal system resulted from inadequate shaping.Coronal leakage and missed canals also contribute to the endodontic treatment failure.

Objective:To discuss the clinical feature and treatment of second mesiobuccal canal (MB2)of permanent maxillary molars. Methods:The root canals of 106 maxillary first molars and 80 maxillary second molars were explored with small size K files. The frequency and morphology of root canals were recorded. The canals of all cases were instrumented by Ni-Ti rotary instruments Hero 642, and obturated with lateral condensation technique. The efficiency of preparation and obturation was analyzed with radiographs before and after treatment. Results:The frequency of MB2 canal in maxillary first and second molars were 82.1% and 45.0%. Most MB2 was very fine and negotiated by size 8 or 10 file combined with EDTA. No transportation, ledge, or perforation was found except that one hand file was separated. Good result of treatment was achieved in most cases. Conclusion:The incidence of MB2 canals of maxillary first molars was higher than that of second molars, and most of them were very fine. The MB2 canals can be negotiated with small size file combined with EDTA, and shaped well with Ni-Ti rotary instruments.