In recent years, numerous studies have elucidated the correlation between DNA methylation and gastric cancer (GC) from the perspectives of early diagnosis, targeted therapy, and prognosis assessment. However, the clinical understanding of their relationship remains incomplete and insufficiently explored. This review will summarize the research progress on the role of DNA methylation in GC, focusing on methylation biomarkers currently approved for GC detection, DNA methylation-based diagnostic markers utilizing liquid biopsy techniques, as well as the relationship between DNA methylation and GC treatment and prognosis. The aim is to provide further insights for the clinical diagnosis and treatment of GC.

Porcine deltacoronavirus (PDCoV) is a major pathogen causing fatal diarrhea in suckling piglets, and there is currently a lack of effective vaccines and drugs to prevent and control the virus. The nonstructural protein 13 (NSP13) serves as a virus-coded helicase and is considered to be a crucial target for antiviral drugs, making it imperative to investigate the helicase activity of NSP13. In this study, the NSP13 gene of PDCoV was synthesized and integrated into the prokaryotic expression vector pET-28a to construct the recombinant plasmid pET-28a-NSP13. NSP13 was successfully expressed in BL21 (DE3) and subsequently purified. The study also verified the helicase activity of the purified NSP13 and explored the factors that influence this activity. The results indicated that NSP13 from PDCoV was effectively expressed in the prokaryotic system and exhibited helicase activity, capable of unwinding double-stranded DNA with a tail at the 5' end. Additionally, NSP13 demonstrated an annealing function by promoting the complementary pairing of single-stranded nucleotide chains to form double strands. The helicase activity of NSP13 was affected by metal ions, but Mg²⁺concentrations in the range of 0.5-6.0 mmol/L had no significant effect on helicase activity of NSP13. When the solution pH was in the range of 4-9, there was no difference in helicase activity. ATP concentrations in the range of 0.25-6.00 mmol/L had a weak effect on helicase activity, and NSP13 concentration ≥80 nmol/L inhibited the helicase activity. We obtained the NSP13 of PDCoV and investigated its helicase activity. These findings provided a theoretical foundation for the further research on the regulatory mechanism of NSP13 in PDCoV replication and the development of anti-coronaviral drugs.
Viral Nonstructural Proteins/metabolism* ; Escherichia coli/metabolism* ; Recombinant Proteins/metabolism* ; Swine ; Animals ; DNA Helicases/metabolism* ; Genetic Vectors/metabolism*

Objective:To investigate the clinical treatment of large segmental humeral defects with unilateral external fixation and bone transport.Methods:A retrospective study was conducted of the 9 patients who had been treated at Department of Orthopedics, Shenzhen People's Hospital for large segmental humeral defects from September 2017 to June 2019. They were 5 males and 4 females with an average age of 29 years (from 21 to 41 years). Their defects were caused by trauma in 2 cases, by chronic osteomyelitis in 6 cases and by bone tumor in one case. The length of bone defect ranged from 4.2 to 9.0 cm, with an average of 5.9 cm. A unilateral external fixator was placed in operation, and adjusted regularly 7 to 10 days after operation for bone transport and bone lengthening to restore the length of humerus gradually. The external fixation bracket was removed after 3 to 4 layers of cortex were observed on X-ray films. Recorded were length and rate of humeral lengthening, fracture healing time, time for carrying external fixator and complications; the Disabilities of the Arm, Shoulder and Hand (DASH) scores were compared between preoperation and 15 months postoperation.Results:All the patients were followed up for 15 to 36 months (mean, 19 months). The length of lengthening averaged 5.9 cm (from 4.2 to 9.0 cm) with an average lengthening rate of 26%, the healing index 31 d/cm, the bone healing time 8.3 months, and the time for carrying external fixator 10.8 months(from 8.0 to 13.5 months). Their average DASH scores improved significantly from 25.0 ± 2.4 preoperation to 12.0 ± 1.8 at 15 months postoperation ( P<0.05). Good correction of large humeral defects was achieved in all but one case who reported temporary radial nerve paralysis. There were no such complications as neurovascular injury. The shoulder and elbow functions were basically normal after operation. Conclusions:In the treatment of large segmental humeral defects, unilateral external fixation plus bone transport can quickly repair the defects and recover the upper limb function of the patients.

ObjectiveTo investigate the mechanism of activated hepatic stellate cells (aHSC) promote the angiogenesis of hepatocellular carcinoma (HCC).MethodsaHSCs were collected after being cultured for 1, 3, 5, 7 d respectively . The relative expression of aHSC angiopoietin-1 (Ang-1) messenger ribonucleic acid (mRNA) was detected by real-time fluorescence quantitative polymerase chain reaction (PCR). The expression of aHSC Ang-1 protein was observed by immunolfuorescence staining. The impact of aHSC on the proliferation of hepatic vascular endothelial cells (HVEC) was observed by Transwell chamber. The impact of aHSC on HVEC tube formation was observed by tube formation assay. The experimental data were compared using one-way analysis of variance and LSD-t test.ResultsAfter aHSC were cultured for 1, 3, 5, 7 d, the relative expression of aHSC Ang-1 mRNA was respectively 1.000±0.024, 1.920±0.080, 6.230±0.320 and 7.820±0.380, which gradually increased as the culture time went on (LSD-t=7.32, 13.68, 8.34;P<0.05). The immunolfuorescence staining showed that Ang-1 and smooth muscle actin antibody (aSMA) were co-expressed in the aHSC. Transwell chamber indirect co-culture showed that aHSC could promote the proliferation of HVEC, and the effect weakened after Ang-1 antibody was added. Tube formation assay showed that HVEC could polymerize and gradually developed tubular structure in the aHSC conditioned medium, and the effect signiifcantly weakened after Ang-1 antibody was added. ConclusionaHSC may promote the proliferation and angiogenesis of HVEC in HCC by secreting Ang-1.

Objective To compare transdermal penetration of triamcinolone acetonide liposparticles (TAA-LPPs) and TAA-Ethosomes in vitro. Methods The TAA-LPPs and TAA-Ethosomes were produced and the morphology was observed by transmission electron microscope,particle size was detected by laser particle analyzer. The percutaneous permeability in vitro was tested by modified Franz diffusion pools. The amount of penetrated triamcinolone acetonide and the retention in the skin were de-termined by HPLC. Results The shape of TAA-LPPs and TAA-Ethosomes was almost spherical with mean diameter of (99. 9±1. 3) and (105±1. 4) nm, respectively. The cumulative transdermal penetration of TAA-LPPs, TAA-Ethosomess and TAA suspension was (53. 59±4. 40),(87. 03±4. 87),and (30. 54±8. 61) μg·(cm2 ) -1 , respectively . The drug retention in the skin after 32 h was (1. 02±0. 13), (0. 62±0. 08), (0. 55±0. 17) μg·(cm2 ) -1 , respectively. Conclusion TAA-LPPs is better for transdermal administration of triamcinolone acetonide by reducing systemic absorption of the drug.

Objective To review the diagnosis and treatment of severe complications after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). Methods Clinical data of 15 patients with severe complications after TACE of HCC in Department of General Surgery, Lingnan Hospital, the Third Afifliated Hospital of Sun Yat-sen University from June 2011 to May 2013 were analyzed retrospectively. The informed consents of all patients were obtained and the ethics committee approval was received. There were 12 males and 3 females with age ranging from 40 to 78 years old and the median age of 55 years old. Results Manifestations of cholangitis such as abdominal pain, fever, rising white blood cell etc. were observed in all the patients. According to the clinical manifestations, history of receiving TACE and imaging examinations, 10 cases were diagnosed with biloma after TACE of HCC, 4 cases with liver abscess and 1 case with ischemic cholangitis. All the patients received basic treatments of anti-infection, cholagogue and liver protection. Ten cases with biloma were cured after receiving ultrasound-guided percutaneous transcatheter drainage of biloma, percutaneous transhepatic cholangial drainage (PTCD) and endoscopic nasobiliary drainage (ENBD). Four cases with liver abscess were cured after receiving ultrasound-guided percutaneous transcatheter drainage of liver abscess, local douche with antibiotics. One case with ischemic cholangitis received drainage of 3 catheters of PTCD and the serum bilirubin went down from 500μmol/L to 300μmol/L, but gave up treatment ifnally because of complicating severe biliary infection and gastrointestinal hemorrhage. Conclusions The diagnosis of severe complications after TACE of HCC is mainly based on the clinical manifestations, history of receiving TACE and imaging examinations. The therapies include basic treatments of anti-infection, cholagogue and liver protection etc., and symptomatic treatments of ultrasound-guided percutaneous drainage, PTCD, ENBD, etc.

Objective To investigate the relation between coagulation disorders and sepsis severity of infected patients.Methods In this retrospective study,75 patients,51 males,24 femalse,with age(55.8± 18.1),were included from January 2010 to March 2011.They were clinically diagnozed as infection,and had Thromboelastography(TEG)and routine coagulation test within 24 hours after admission to emergency department.They were divided into 3 groups based on SIRS and SOFA score within 24 hours after admission:a)infection group,patients without SIRS; b)sepsis group,patients with SIRS and SOFA score less than 5; c)severe sepsis group,patients with SOFA score greater than or equal to 5.LSD was used to compare between two groups if one-way ANOVA of three groups comparasion showed significant differences.Results In comparasion to sepsis group(n =29)and infection group(n =27),D-dimer elevated significantly in severe sepsis group(n =19)(F =3.388,P =0.004),and platelet count decreased significantly(F =3.839,P =0.026),INR and KPTT showed an increase trend without significant difference (F =2.657,P =0.077 ; F =2.782,P =0.069); TEG showed MA obviously decreased(F =5.841,P =0.004),while there were nostatistically significant differences among other data.Conclusions The extent of coagulation disorders and sepsis severity of infected patients is closely correlated to each other.

Objective To evaluate the effect and safety of combined treatment by laparoscopic cholecystectomy and subsequent ablation in patients with HCC adjacent to the gallbladder. Methods From June 2005 to June 2009,13 patients with HCC nodules( less than 3 cm) adjacent to the gallbladder were treated by ablation after laparoscopic cholecystectomy. The rate of complete necrosis as well as postoperative complications were also analyzed. Results All the patients showed complete necrosis of their tumor lesions after treatment by ablation subsequence of laparoscopic cholecystectomy. During the follow-up period( nearly 2 years), recurrent nodules appeared in other subsegments but not at the original site treated by ablation. Of note, no fatal complications were observed in all the ablation treated patients. Conclusion Combined treatment by laparoscopic cholecystectomy and subsequent PMCT was an effective and safe method for patients with small HCC which was adjacent to gallhladder.

BACKGROUND: There is no accepted treatment for liver fibrosis recently. Bone marrow meaenchymal stern cells (BMSCs) used in the treatment of liver fibrosis has been reported as an effectively treatment, but the mechanism is unclear.OBJECTIVE: To study the regulation of hepatic stellate cells mediated by human BMSCs in vitro.DESIGN, TIME AND SETTING: The cytological in vitro study was performed at the Center for Stem Cells and Tissue Engineering of Sun Yat-sen University and the Central Laboratory of Third Affiliated Hospital of Sun Yat-sen University from June to December 2008.MATERIALS: Human bone marrow masenchymal stem cells were collected from normal youth volunteers; Human hepatic stellate cells and normal liver call line L-O2 were supplied by the Animal Experimental Center of Sun Yat-sen University.METHODS: The purified human BMSCs and hepatic stellate calls were set up in Transwell co-culture system. The incubation density was 2×104cells/well. L-O2 was set up instead of human BMSCs as negative control. Hepatic stellate cells cultured alone served as blank control group. The culture was performed for 72 hours.MAIN OUTCOME MEASURES: Morphology of hepatic stellate cells and results of immunocytochemical staining. Apoptosis of hepatic stellte calls was determined by flow cytometry. Western blot were used to assay the expression of α-actin.RESULTS: Activated hepatic stellate cells presented fiat and thin shape under an inverted microscope. Fat drop was lack in cytoplasm, a -actin located in hepatic stellate calls, with the presence of high tension fibers. Compared with the L-O2 + hepatic stellate cell and hepatic stellate call groups, the apoptotic rate of hepatic stellate cells was significantly increased in the BMSC + hepatic stellate cell group (P < 0.05). α -actin expression was significantly down-regulated.CONCLUSION: Human BMSCs can inhibit activation of hepatic stellate ceils and promote them apoptosis, which may be the anti-hepatic fibrosis mechanism of BMSCs.

Objective To construct the bioartificial liver by bone mesenchymal stem cell (BMSC) and alginate scaffold. Method Alginate scaffold was used as the cell carrier for the cultivation of BMSC and the differentiation from BMSC into hepatic like cells was induced by the cell factors of HGF, EGF and FGF-4 in the scaffold in vitro. The compatibility of the cells and the scaffold was observed by microscopy and the function of the differentiatd cells was tested. The gene of AFP and ALB was detected by RT-PCR. The secretion of ALB and the urea synthesis of the cells were tested by ALB kit and urea kit respectively. The glycogen synthesis and the CK-18 was tested by the glycogen stanning method and the immunofluorescence test. Results BMSC was able to attach, grow and proliferate well in the alginate scaffold, the well compatibility was observed by microscopy. ALB and urea were detected in the cultivating medium, the gene of ALB and AFP was identified by RT-PCR. The glycogen synthesis ability and the expression of CK-18 were induced during the differentiation. Conclusion The three dimensional atginate scaffold exhibited well compatibility with BMSC, BMSC could be differentiated into the hepatic like cell in the scaffold. BMSC and the alginate scaffold could be used to construct the bioartificial liver for the hepatic tissue engineering.