Histone methyltransferase modulates heterochromatin formation,genomic imprinting and genetic transcription by regulating the combination of histones and DNA.As encoding genes of histone methyltransferase,mixed-lineage leukemia (MLL) genes are found to have close relationship with tumors.Recently,MLL2,a member of this family,has been found highly expressed anomalously in breast cancer,colorectal cancer and lymphoma.Whether MLL2 participates in the progression of cancer,the time phase of its participation and its specific role are still remained to further study.

The aim of this study was to investigate if there are abnormal fibroblasts derived from the skin surrounding keloids in order to have a better understanding for keloid progression. All the samples were used for cell culture. Flow cytometry was used to compare the apoptotic rate of fibroblasts derived from keloid and its surrounding skin, when it was cultured in serum-deprived medium for 24 hours or was induced by Fas antibody. After cultured in serum-deprived medium for 24 hours, the apoptotic rate of fibroblasts derived from the surrounding skin of keloid increased to an amount between that of normal skin and keloids. The apoptotic rate of normal skin fibroblasts increased more than that of keloids. Moreover, when induced by Fas antibody, the apoptotic rate of fibroblasts derived from the surrounding skin increased not so high as that of normal skin(P0. 05). Therefore, at least there are some fibroblasts in the surrounding skin of keloids, in which apoptosis can not be induced as in normal skin.

BACKGROUND:Lipopexia induced by glucocorticoid is fat precipitation in marrow due to abnormal lipomatabolism,or differentiation of cells resulting from hormone-affected bone marrow mesenchymal cells.The precise generating procedure remains unclear.OBJECTIVE:To Jnvastigate effects of vadous concentrations of dexamethasone on adipogenic differentiation of bone marrow mesenchymal cells.DESIGN,TIME AND SETTING:The observational study was performed at the Department of Biochemistry,China Medical University from January 2007 to January 2009.MATERIALS:A total of 80 Sprague-Dawley rats aged 3 or 4 weeks,weighing (110±10) g,of both genders,were used in this study.METHODS:Rat bone marrow mesenchymal cells were isolated and subcultured.Bone marrow masenchymal cells at the third passage were used as samples.MAIN OUTCOME MEASURES:Cellular morphologic changes after treatment of 10~(-7) mol/L dexamethasone were observed under an inverted microscope,as well as at 3,7,14 and 21 days under normal culture condition.Morphological changes of bone marrow mesenchymal cells were observed following alkaline phosphatase and Sudan Ⅲ staining.Alkaline phosphatase activity was measured using phenol reagent.Effects of dexamethasone on cell proliferation were measured using MTT assay.RESULTS:Following 24 hours of incubation,a few adherent cells were found in the bottom of the culture flask,showing spindle shape.With prolonged time,adherent cells became more,presenting radiated shape.Following passage,cells distributed uniformly,showing typical fibroblast-shape.Following dexamethasone stimulation,cells changed from spindle-shape into polygonal or irregular shape.In the late phase,with increased concentration and prolonged time,cell colonies disappeared;cells adhered,and died.In normal cultured cells,no or a few orange particles were found.In dexamethasone-cultured cells,with increased hormone concentration and prolonged time,Sundan Ⅲ stained particles increased.At 21 days,alkaline phosphatase activity under normal culture was separately 1.57-,4.49-and 5.0-fold of 10~(-8),10~(-7),10~(-6) mol/L dexamethasone group.At 7,14 and 21 days,alkaline phosphatase activity under normal culture was separately 2.93-,3.80-and 4.39-fold of 10~(-7) mol/L dexamethasone group (P ＜ 0.05).High concentration of dexamethasone had significant inhibitory effects on cell proliferation activity.Significant difference was detected as compared 10~(-7) mol/L and 10~(-6) mol/L to other groups (P ＜ 0.05).CONCLUSION:High-dose dexamethasone enhances adipogenic and suppresses osteoblastic differentiation of bone marrow mesenchymal cells.The effect will increase along with the increasing content and prolonged duration of demamethasone stimulation.

Objective To understand the pathogen of viral encephalitis(VE)in children,and establish a rapid and specific method for detecting human rhinovirus(HRV),and investigate the correlation between HRV and viral encephalitis(VE). Methods 169 CSF specimens were collected from children with convulsions and fever,who were admitted to the pediatric intensive care unit (PICU)of Second Affiliated Hospital of Shantou University Medical College between January 2012 and December 2012.Nested RT-PCR was used to detected HRV in CSF specimens,and the positive PCR products were se-quenced,then analyzed and constructed the phylogenetic tree by software.Results 39 (23.1%)out of 169 samples were HRV positive.Among them,148(87.6%)children were below 5 years old.The detection rate of HRV increases from July to September,and reached its highest point in September.Sequence analyzed showed that the 39 HRV positive specimens inclu-ding 18(46.1%,18/39)positive for HRV-A,7(17.9%,7/39)positive for HRV-B,14(35.9%,14/39)positive for HRV-C. There were 8 out of 28 VE cases were detected in HRV,including 3(50%,3/6)positive for HRV-C.Conclusion HRV could be detected in CSF specimens by nested RT-PCR,including three types of HRV,combined with clinical symptoms con-sidered that HRV may be one of the VE pathogen.

Despite tre mendous research efforts have been devoted to the analysis of nanoparticles (NPs)biohazard,the potential mechanism for nanotoxicity has not yet been syste mati-cal y elucidated.This review intends to point out the confusions about nanotoxicity in the field and tries to look into the mecha-nism from a new perspective.Currently,there are three puzzles:① no relationship between dose and toxicity could be observed in nanotoxicity;②there is a theory for the″size effects″,however, it cannot explain some cases contrary to the doctrine;③ NPs made of different materials with various sizes could have the same toxic effects through sti mulating oxidative stress.In fact, human body is co mposed of various biological molecules,and the biological function of a living syste m is reflected by the inter-actions and conversions of those molecules.NPs,on the other hand,are the invader of human body which has no ability to transport or convert or digest the foreigner.Thus,NPs could cause celldamage due to the physical blockage of micro-circula-tion,celldestruction due to membrane rando m insertion,and celldysfunction due to physical contacting with big biological mole-cules.The physical damages caused by various NPs could be divided into three categories:adhesion lesion,card inlay and puncture.Above al ,by analyzing wide spectrum of NPs varying in co mposition,shape and size,the author draws a conclusion that physical damage is the origin of nanotoxicity.

Objective To study the technique of lumbar cathetering in lumbosacral vertebral canal operation and its effect on prevention of postoperative cerebrospinal fluid leakage.Methods Retrospectively analyzed the clinical data of patients who underwent lumbosacral ver-tebral canal surgery and suffered from difficult dural repair during the operation in Department of Neurosurgery from August 2015 to October 2015.These patients were divided into the observation group (11 cases)and the control group (12 cases)according to whether lumbar cathe-ter were placed during the operation or not.Volume of drainage was strictly controlled after surgery.Remove the epidural drainage after primi-tive healing of the dura mater.The lumbar catheter was removed after 7 to 10 days.The indwelling time of each patient was collected and sta-tistical analyzed.Results The observation group got obvious shorter epidural drainage indwelling time than the control group(P <0.05). Short-term postoperative complications did occur in some cases in observation group,however,there was no obvious increase of infection rate in patients with lumbar continuous drainage indwelling.Conclusion Lumbar cathetering during the operation could be an effective method to solve difficult problem of placeing a lumbar drainage after lumbar puncture and to prevent cerebrospinal fluid leakage after operations of lum-bosacral vertebral canal.But it can not replace the delicate operation and tight dural suture.Drainage should be used only as a remedial measure of dural repair failure.

Objective:To investigate the effects of TGF-?1 on promoter activity of human transforming growth factor-beta1(TGF-?1) gene.Methods:The fragments with different length of the 5′-end sequence of the human TGF-?1 gene between -1 328 bp to +812 bp were obtained from a healthy male person genomic DNA, and the sequences were fused to chloramphenicol acetyltransferase reporter gene in the pCAT-enhancer plasmid to construct five chimeric recombinant plasmids. These recombinant plasmids were transiently transfected into rat hepatic setellate cell line(nFSC) by FuGENE6 transfection methods. The cells transfected with chimeric recombinant plasmids were cultured on media in the absence or presence of TGF-?1(2 5 ng/ml),CAT activities in transfected cells were tested and compared.Results:The different concentration of TGF-?1 can prevent the proliferation of nFSC, and these effects are dose-dependent; The presence TGF-?1 can stimulate the CAT activity of cells transfected with phTGF0 585?phTGF1 120?phTGF1 423?phTGF1 680?phTGF2 140 up to 2～5 times higher then cells cultured with absence of TGF-?1.Conclusion:The TGF-?1 can stimulate CAT activities in nFSC transfected with phTGF0 585?phTGF1 120?phTGF1 423?phTGF1 680?phTGF2 140. These results suggest that TGF-?1 have an autoregulation effect on TGF-?1 gene.

OBJECTIVE To investigate and analyze the pathogenic bacteria of burn infection and their drug resistance in recent 5 years from 2001.METHODS The patients were divided into two groups.The group 1 included patients from Jun 1996 to May 2001 and the group 2 was from Jun 2001 to Jun 2006.Burn wound bacteria were cultured,and identified and their drug sensitivity was analyzed.RESULTS In burn wound culture,in group 2 Pseudomonas aeruginosa with the rate of 30% was still in the 1st place.Staphylococcus aureus was in the 2nd place with the rate of 28.2%.The G-bacilli comprised 58.2% and the G+ cocci 40.3 %.Proteus mirabilis,Acinetobacter baumannii,Enterococcus faecalis and Candida albicans increased remarkably.The drug resistant percentage of P.aeruginosa,Enterobacter cloacae and Escherichia coli to third generation cephalosporin increased greatly.CONCLUSIONS The changes of pathogenic bacteria of burn infection and bacteria drug resistance have certain relations with the wide usage of broad spectum antibiotics such as cephalosporin and imipenem.

Objective To investigate the effects of intratumoral implantation of ~(32)P-CP-PLLA seeds on the normal canine liver tissue and to exolore the metabolism of ~(32)P-CP-PLLA seeds implanted in the liver of experimental dogs.Methods Twelve beagles were enrolled in this study.The dogs were randomly and equally divided into four groups:group A(185 MBq),group B(370 MBq),group C(740 MBq)and group D(0 MBq).By using laparotomy procedure ~(32)P-CP-PLLA seeds were implanted into dog's liver.CT scan was performed before operation as well as before the dog was sacrificed.All dogs were sacrificed three months after the implantation.Before the procedure and 1,2,4,8 and 12 weeks after the procedure the blood tests and serum biochemical tests were conducted.One dog from group B and group C was selected respectively and was fed in a metabolic cage.Within one month after the procedure the cpm in feces and in urine was determined every 24 hours.One dog was picked out from each of the three groups and was punctured to get its liver tissue for pathologic exam each time at 1,2,4,8 and 12 weeks after the implantation,and SPECT imaging was also performed at the same time.Pathologic study,both macroscopic and microscopic(including optical and electronic microscopy)was made to observe the liver damage after the dog was sacrificed.The statistical analysis was processed by using SPSS 13.0 software and the measuring data were expressed with mean±standard deviation((x)±s).Results Two months after the procedure,serological examination found that the serum alkaline phosphatase(BKP)in both group Band group C was significantly higher than that in other groups,the difference was statistically significant (P ＜0.05),and the BKP levels returned to normal in three months.The postoperative 30-day inspection of the urine showed that the radioactive particles slowly released into the body and eliminated from the body with the urine and feces,mainly through the renal excretion.The 30-day cumulative percentage of eliminated radioactive dose in the urine and in the feces was 6.34% and 11.64% respectively.No sign of particle displacement was found on SPECT imaging.On autopsy three months after the implantation,the size of the radioactive seeds became smaller and fragile.With the radioactive dose used increasing,the area of liver damage at the site of seed implantation became bigger,which was demonstrated on CT scan,macroscopic exam and pathologic study.The local damaged focus of the liver caused by ~(32)P-CP-PLLA seeds was manifested as a spherical lesion which was encysted by a layer of fibrous tissue with an edematous zone peripherally.Conclusion The implantation of ~(32)P-CP-PLLA seeds in dog's liver causes only localized hepatic damage with no general adverse effects.The implanted seeds can slowly release the radioactive dose and will not immigrate to other organs in the body.Besides,the seeds possess excellent stability,targeted orientation and safety.

Nowadays, nanotechnologies have shown wide application foreground in the biomedical field of medicine laboratory tests, drug delivery, gene therapy and bioremediation. However, in recent years, nanomaterials have been labeled poisonous, because of the disputes and misunderstandings of mainstream views on their safety. Besides, for the barriers of technical issues in preparation like: (1) low efficacy (poor PK & PD and low drug loading), (2) high cost (irreproducibility and difficulty in scale up), little of that research has been successfully translated into commercial products. Currently, along with the new theory of "physical damage is the origin of nanotoxicity", biodegradability and biocompatibility of nanomaterials are listed as the basic principle of safe application of nanomaterials. Combining scientific design based on molecular level with precision control of process engineering will provide a new strategy to overcome the core technical challenges. New turning point of translational medicine in nanotechnology may emerge.