DNA methylation is an important epigenetic system. It plays many crucial roles in the gene regulation. With the development of the high-throughput detection techniques, the bioinformatics study has been an active hot topic in the research of DNA methylation. The major achievements and progress on the prediction of DNA methylation status, the mechanism that the majority of CpG islands are resistant to DNA methylation, the relationship between DNA methylation and other epigenetics, as well as the association between aberrant DNA methylation and the tumorigenesis were reviewed in this article.

Objective:To investigate the change in myogenin expression at different time in long-term denervated human posterior cricoarytenoid muscles(PCAMs),so as to provide a theoretical basis for timing of reinnervation.Methods: Thisty-eight specimens of denervated human PCAMs were divided into 4 groups according to the period of denervation: 6-12 months denervation group(n=12),1-2 years denervation group(n=10),2-3 years denervation group(n=8),and over 3 years denervation group(n=8).Another 12 specimens of normal PCAMs served as control.The patients in all groups were age-and sex-matched.The expression of myogenin protein and mRNA was studied using immunofluorescence staining and real-time PCR analysis,respectively.Results: Immunofluorescence staining showed that the positive myogenin expression was mainly!found in the myonuclei of PCAMs with a denervation period less than 3 years;no positive staining was found in the myonuclei of control group.The expression of myogenin in myonuclei and the ratio of positive cells were up-regulated in the 6-12 month denervation group compared with those in the control group;the expression and the ratio peaked in 1-2 years denervation group and decreased again in the 2-3 years denervation group,but was still significantly higher than those of the control group(all P

Objective:To study the morphological changes of posterior cricoarytenoid muscles(PCM) in patients with long-term denervation of recurrent laryngeal nerve(RLN),so as to provide theoretical evidence for repair of recurrent laryngeal nerve at advanced clinical stage.Methods: Thirty-eight patients with damaged RLN were divided into 4 groups according to the duration of their RLN damage: 6-12 months group(n=12),1-2 years group(n=10),2-3 years group(n=8),and over 3 years group(n=8).Twelve subjects with normal PCM served as control.Trichrome Masson staining and imaging analyzing system were used to quantitatively analyze the transverse section areas of myofibers,collagen fiber and connective tissues.SDH and AchE staining and cell counting method were used to analyze changes of two kinds of myofibers and motor end plate numbers at different times after denervation of recurrent laryngeal nerve.Results: The transverse areas of myofibers gradually decreased and those of collagen fibers gradually increased with the prolongation of denervation;the difference was significant between different groups(P

Objective To investigate the changes of the expression of GDNF and GDNFR?1 of long-term denervation of posterior cricoarytenoid muscles(PCAMs).Methods 38 patients with vocal paralysis were grouped into four according to their denervated period of time while 12 normal PCAMs as control group.Using double immunofluorescence stain,changes of GDNF and GDNFR1 expression were observed in myofibers at different time points after denervation.Results Double immunofluorescence stain with antibodies against GDNF and GDNFR1 showed no staining in the control group,and study groups.However,after the muscle denervation lasted for 6-12 months and 1-2 years,noted was a significant accumulation of GDNF and GDNFR1 protein in cytolemma and endochylema of myofiber.The mean grey scales and positive region ratios were compared using the image analysis system.The results revealed the levels of GDNF and GDNFR1 protein expression in 6-12 months group,1-2yr group changed significantly(P0.05).Conclusion The changes in expression of GDNF and the acceptor GDNFR-?1,a powerful neurotrophic factor,implied that a good nervous regenerated microenvironment in PCAMs within 2 years.This experiment indicated that denervated posterior cricoarytenoid muscles are able to regain their functions through reinneration within 2 years.

In the era of outbreaking of antibiotic resistance, the discovery of new antibacterial drugs is emergent.Antimicrobial peptides are important components of the natural defenses of most living organisms against invading pathogens.The unique antibacterial mechanism, direct bactericidal effect, relatively slow of resistance acquirement, and can used alone or combined with antibiotics, make antimicrobial peptides be attractive potential antibacterial drugs.In this paper, we review the physicochemical property of antibacterial peptides, action mechanism and design of antimicrobial peptides, and give a brief introduction of several promising antimicrobial peptides.

To isolate human phage single chain antibody against surface protein of Streptococcus mutans,the recombinant surface protein of S.mutans(rAP) was used to coat the immune tubes and the phage single chain antibody was prepared through pDAN5 phage antibody library after 5 rounds of panning.The eluted phage was enriched nearly 30 times.In these ways,13 positive clones were obtained and found to be able to bind with rAP in ELISA assay.Then one of the 13 positive clone phage plasmid was used to infect E.coli HB2151 to induce the expression of the non-fusion single chain antibody (ScFv) with IPTG induction.As demonstrated by SDS-PAGE,the molecular mass of this single chain antibody was proved to be 30 kDa and the amount of expression constituted to 30% of the total bacterial proteins.Apparently,the human phage single chain antibody against surface protein of S.mutans with biological activity was successfully screened.

Objective To investigate the morphology change of posterior cricoarytenoid muscle myofiber in patients with idiopathic vocal fold paralysis and to provide experimental evidence for the clinical treatment of idio‐pathic vocal cord paralysis .Methods Thirty -nine cases of vocal fold paralysis patients were recruited into and di‐vided into 2 groups :idiopathic vocal cord paralysis group(n=16) ,and traumatic vocal cord paralysis group(n=23) . Both groups were further divided into 3 subgroups:0 .5~1 year(5 cases and 7 cases) ,>1~2 years(5 cases and 10 cases) ,>2 years(6 cases and 6 cases) .Part of posterior cricoarytenoid muscle(PCAM ) were acquired from all of vo‐cal cord paralysis patients .Normal human posterior cricoarytenoid muscles were treated as the control group (n=5) . They were all stained with Masson three-color staining ,the fiber crosssectional area of muscle tissue and collagen connective tissue were quantitatively analyzed with the image pro plus analysis system .Differences of two observa‐tion indexes were compared with each other among groups and subgroups .Results The number of myofibers was decreased ,but the numbers of the collagen fibers was increased with the onset time course extension ,the ratio of cross sectional area of myofibers to those of collagen fibers was progressively decreasd with increased time course of denervation and more decrease within 1 year .There was obvious difference between the control group and 0 .5~1 year ,>1~2 years ,>2 years subgroup of idiopathic vocal cord paralysis (P<0 .05) .Although without no signifi‐cant difference between >1~2 years subgroup and >2 years subgroup ,the trend of shrinking still existed .Com‐pared two observation indexes of traumatic vocal cord paralysis with the same period subgroup indexes of idiopathic vocal fold paralysis ,there was no significant difference about these two observation indexes (P>0 .05) .In some special cases with 10 years duration in idiopathic vocal cord paralysis group ,the posterior cricoarytenoid muscle at‐rophy fibrosis was not serious .However ,in some case which the course lasted for only 1 .5 years ,the muscle atrophy was very obvious .There were great individual differences among idiopathic vocal cord paralysis patients .Conclusion If there is no recovery after half year treatment ,for PCA muscle function recovery ,the recurrent laryngeal nerve injury repair surgery could be considered to carry out within 1 year .In some cases with long disease duration (>2 years) ,they may still have the muscle morphological basis for nerve repair .

Objective To evaluate the efficacy of modified arytenoid adduction in the management of patients with unilateral vocal fold paralysis(UVFP).Methods A retrospective review was performed on 22 patients who underwent modified arytenoid adduction for UVFP between February 2001 and December 2007.Pre-,and 3 months postoperative aspiration,perceptual(GRBAS),acoustic data(fundamental frequency,F_0,fundamental frequency perturbation,jitter,amplitude perturbation,shimmer,normalized noise energy,NNE)and aerodynamic(maximal phonatory time,MPT,mean airflow rate,MFR)were analyzed statistically.Results The ratings of postoperative aspiration were significantly decreased than that of the preoperation(P<0.0001).There was a significant decrease in GRBAS scales postoperatively versus preoperatively(P<0.0001).The mean values of voice acoustics parameters (F_0,jitter,shimmer,NNE)were significantly decreased,the maximum phonation time were significantly longer,and the mean airflow rate were significantly decreased after operation than that of the preoperation(P<0.001).Conclusion Modified arytenoid adduction is an effective medialization technique that can restore satisfactory speech and prevent aspiration in patients with UVFP.

Objective To design a new Chinese mandarin version of speech sample text for perceptual assessment .Meth-ods The speech sample text included all phonemes and limit number of words .The correlation analysis of the constituent rati-os of all phonemes was performed between the speech text and the ones in Chinese language reported by the institute of Acous-tics Chinese Academy of Sciences using Pearson's correlation coefficient and Spearman correlation coefficient .And their differ-ences were tested by paired sample t test and Wilcoxon signed rank test .Legibility was alsotested .Results Our speech sarrple text contained 21 vowel ,38 consonant and 4 tones .The proportions of vowel ,consonant and tone in the speech text had high correlation with those in Chinese language (for proportions of vowel ,the Pearson's correlation coefficient was 0 .908 and Spearman correlation coefficient was 0 .775 ,P<0 .01 ,respectively ;for proportions of consonant ,the Pearson's correlation co-efficient was 0 .802 and Spearman correlation coefficient was 0 .808 ,respectively ,P<0 .01 ;for proportions of tone ,the Pear-son's correlation coefficient was 0 .967 and Spearman correlation coefficient was more than 0 .999 ,respectively , P< 0 .01) . There was no difference in the proportions of vowel ,consonant and tone between them(P>0 .2) .The value of legibility was 2 , indicating legibility of the speech sample text was good .Conclusion The new Chinese mandarin version of speech sample text can be used in perceptual assessment .The value for perceptual assessment still needs further clinical research .

Objective To evaluate the effects of Xuebijing injection on inflammatory mediators of patients with severe acute pancreatitis. Methods Using double blind method, 80 cases with severe acute pancreatitis were randomly divided into two groups, with 40 cases in each group. The control group was treated with conventional therapy such as: fasting, fluid replacement, acid inhibition and anti-infection, combined with the continuing injection with the growth hormone release inhibiting 6 mg, ulinastatin 200000u for 7 days. Based on the control group's treatment, the other group was added with Xuebijing injection 50 ml, twice a day for 7days. The plasma levels of prostaglandin Ⅰ2 (PGI2), thromboxane A2 (TXA2), tumor necrosis factor α (TNFα),interleukin-1,6,8 (IL-1,6,8) were compared before and after the treatment in each group and between two groups.Results Compared with the control group, Xuebijing injection group had marked effects on modulating the levels of inflammatory mediators. The levels of PGI2 and PGI2/TXA2 were increased significantly and the levels ofTXA2, TNF2, IL-1,6 and 8 were deceased(P＜0.05)sharply after the treatment. Conclusion Combined with conventional western medicine therapy, Xuebijing injection has the effects of inhibiting and controlling the release of inflammatory mediators on patients with severe acute pancreatitis.