Group A β-hemolytic streptococcus (GAS),namely Streptococcus pyogenes,is one of the most im-portant human pathogen.GAS can cause skin and mucous membrane superficial infectious diseases,life -threatening invasive disease,toxin -mediated diseases and immune -related diseases.Antibiotic is an effective mean to control GAS infection.The β-lactam antibiotics remain the first -choice treatment for GAS infection and the macrolides are often recommended as a replacement therapy for β-lactam antibiotics allergic patients or a means to blocking GAS exotoxin product.But with the widespread use of macrolides autibiotics,macrolide -resistant GAS spread in the world. This paper will elaborate the situation of macrolide -resistant clones.

Objective To investigate the changing characteristics of muscle mass by dual energy X-ray absorptiometry (DEXA) in middle aged and elderly people with different ages.Methods This study included 343 healthy people aged 50-89 years (178 males and 165 females).Subjects were divided into 4 groups:aged 50-59,60-69,70-79,and 80-89 years group.Fat-free body mass (FFM),the appendicular lean body mass (aLM),trunk lean mass (tLM) were measured by DEXA.The aLM/body weight (Wt％) and aLM index (ASMI) were calculated by DEXA.Results The tLM in both gender was decreased in aged 80-89 years group than in aged 50-59 years group [male (10.6± 1.8) kg vs.(18.4±2.9) kg,female (7.1±1.2) kg vs.(14.8±2.1) kg,F=5.7 and 7.8,P＜ 0.01].The average ASMI in both gender was decreased in aged 70-79 and 80-89 years groups than in aged 50-59 years groups [male (5.5±0.4) kg/m2,(4.9±0.7) kg/m2 vs.(6.1±0.5) kg/m2,female (4.3±0.4) kg/m2,(3.9±0.5) kg/m2 vs.(4.8±0.6) kg/m2,F=24.9 and 9.6,both P＜0.01].The quality of muscle mass was decreased with aging in the elderly.Conclusions Ageing is an important risk factor for sarcopenia in the elderly.DEXA can be used to evaluate the muscle mass in middle aged and the elderly,and ASMI can be used as a reliable measurement index.

BACKGROUND:Cholesterol is closely linked to the occurrence and progression of atherosclerosis. Current approaches to study celular cholesterol dynamics have their own limitations.
OBJECTIVE: To measure the cholesterol efflux rate of RAW 264.7 mouse macrophages by BODIPY-Cholesterol labeling and to explore the effects of extracelular cholesterol and lipopolysaccharide on the cholesterol efflux rate.
METHODS:RAW 264.7 cels were cultured in vitro with DMEM containing 10% fetal bovine serum, and labeled with BODIPY-Cholesterol for 1, 2, 4, 8 hours. Then, the cels were rinsed with serum-free DMEM and inoculated for 6, 12, 24, 48, 96 hours to optimize the labeling time and incubation time. We measured and compared the cholesterol efflux rates after cultured cels were treated with cholesterol, lipopolysaccharide, human sera with high cholesterol or human sera with normal cholesterol.
RESULTS AND CONCLUSION: The best labeling time for BODIPY-Cholesterol was 2-8 hours. Cholesterol efflux rates were gradualy decreased after the cels that were labeled for 2 hours were incubated with increasing concentrations of cholesterol (0.1, 0.5, 2.5 mmol/L,P< 0.01). Treating cels with lipopolysaccharide also decreased the cholesterol efflux rate (P < 0.05). Furthermore, the cholesterol efflux rate was decreased after cels were treated with human sera with high cholesterol (P< 0.05). These findings indicate that BODIPY-Cholesterol can be used to measure celular cholesterol efflux rate and to study the effects of extracelular cholesterol and lipopolysaccharide on the cholesterol efflux rate.

Objective To observe the application effect of Yunnan baiyao powder and alcohol with VitB12 on exosmosis of vincristin. Methods The 40 patients with exosmosis of vincristin were randomly divided into the treatment group(22 cases)and the control group( 18 cases).The treatment group was given the Yunnan baiyao powder and alcohol with VitB12,the control group was given magnesium sulfate for hydropathic compress.The effective rate and red swelling and ulcer of the skin in the two groups were evaluated. Results The effective rate of the treatment group was higher than that of the control group,red swelling and the diameter of the ulcer of the skin on the fifth and seventh day were shorter than the control group. Conclusions The Yunnan baiyao powder and alcohol with VitB12 are effective in treatment of the exosmosis induced by vincristin.

Objective To analyze the diversity of intestinal microecology in different healthy age groups and explore the relationship between age and the composition of intestinal microflora.MethodsFecal samples were collected from the children,adult and elderly groups.The main intestinal microflora were cultured and quantified,and the qualitative and quantitative changes in the level of category were determined by fluorescence quantitative PCR.The Bifidobacteria/Enterobacteriaceae (B/E) ratio reflexing intestinal colonization resistance was also calculated.Results The germiculture of fecal samples indicated that the counts of Bifidobacteria and Lactobacillus (P＜0.01 and P＜0.05,respectively) were significantly lower in the adult and aged groups than in children group.The number of Bacteriodes and Enterobacteriaceae in the elderly group were higher than in the children and the adult groups (all P＜0.01).The counts of Enterococcus were increased in the adult and the aged groups (P＜0.05 and P＜0.01) compared with the children group,and were higher in the aged group than in the adult group (P＜0.05).The B/E ratio was significantly decreased in the aged group (0.88-±-0.13) as compared with the children (1.15±0.15) and the adult groups ( 1.01± 0.20) ( both P ＜ 0.01).The diversities of Bifidobacteria,Bacteriodes,Enterobacteriaceae and B/E ratio by fluorescent quantification PCR were consistent with the results by germiculture technology.The diversity of Lactobacillus (P＜0.01) between the children and the aged groups as well as between the children group and the adult group significantly improved (P＜0.01 and P＜0.05 ) in PCR compared with the germiculture technology. ConclusionsThe numbers of intestinal Bifidobacterium and Lactobacillus are decreased with lower colonization resistance,while the numbers of Bacteriodes,Enterobacteriaceae and Enterococcus are increased with aging.

Objective To investigate the effects of Mandarin speech rate on Mandarin acceptable noise level test in normal hearing adults.Methods Using the national Putonghua proficiency test material to produce 0.8 times,1.0 times and 1.2 times speed rate of ANL test materials.ANL tests were measured for 58 normal hearing a-dults using different peed matetrials.For each case,the most comfortable loudness(MCL)and background noise lev-el(BNL)were found.The ANL was then computed by subtracting the mean BNL from MCL.ResuIts Statistic anal-ysis indicated that there were no significant differences of the ANL(P>0.05)among the differenct speed materials, there were no correlation between MCL-ANL (P>0.05),negatively correlation between BNL-ANL(P<0.05)a-mong the differenct speed materials.ConcIusion Mandarin speech speed does not effect ANL test,the more the in-dividual’s ability to accept the background noise,the smaller the value of ANL.

Objectives To investigate clinical features and the risk factors for 30-day death in elderly chest pain patients.Methods In the prospective study,514 patients with acute chest pain leading to emergency department visit were selected from March 2012-August 2010 and grouped into elderly group (aged≥65 years,n=309) and non-elderly group (aged< 65 years,n=205).The patient's clinical data during 30-day follow-up period were recorded for analysis and comparison.Multivariate regression analysis was used to investigate the risk factors of death.Results Among 514 cases with acute chest pain,30(5.8%)patients with all-cause death included 24 cases in group of 309 (7.8%) elderly patients and 6 (2.9%) cases in group of 205 non-elderly patients during 30 day follow-up period.Univariate regression analysis showed that female,low SBP,Killips' classification ≥ Ⅱ,high level of serum troponin T and creatinine,coronary artery ischemia were more likely to died during 30 day follow-up period.And female and Killips' classification ≥ Ⅱwere the independent factor for 30-day death in the elderly[OR:3.55 (95%CI:1.00-12.59) and 5.90 (95%CI:1.31-26.63)]respectively.Conclusions Elderly patients with acute chest pain for first emergency department visit are at high risk for 30-day death.Female and cardiac function Killips' classification ≥ Ⅱ,high levels of serum troponin T and creatinine and coronary artery ischemia are associated with 30-day death in patients with acute chest pain for first emergency visit.Female and Killips' classification ≥ Ⅱare the independent risk factor for 30-day death.

Objective To investigate the clinical characteristics of children with medulloblastoma (MB). Methods The correlations amongst MB histopathological subtype,age at diagnosis,gender,primary tumor locations, relapsed tumor and relapsed tumor locations were analyzed retrospectively in 83 children who were diagnosed as MB by histopathology subtypes from February 2012 to April 2015 in Beijing Shijitan Hospital Affiliated to Capital Medical Uni-versity.The data was conducted by using SPSS 22.0 statistical software.Results Among the 83 cases (53 boys and 30 girls),there were 14 patients younger than 3 years old (9 boys and 5 girls)and 69 patients (44 boys and 25 girls)ol-der than 3 years old,including 28 relapsed (19 boys and 9 girls)and 55 non -relapsed cases (34 boys and 21 girls). The median age was 80.2 (13.1 -184.7)months at diagnosis.Of these 83 cases,48.2% (40 /83 cases)was classic medulloblastoma (CMB)(2 cases less than 3 years old),24.1 % (20 /83 cases)was desmoplastic /nodular medullo-blastoma (DMB)(6 cases less than 3 years old),12.1 % (10 /83 cases)was large cell/anaplastic medulloblastoma (LC /AMB)(1 case less than 3 years old),3.6% (3 /83 cases)was extensive nodular medulloblastoma (MBEN)(1 case less than 3 years old),and 12.1 % (10 /83 cases)(3 cases less than 3 years old)was mixed subtype.The rela-tionships between age at diagnosis and histopathological subtype,gender and primary tumor location were all statistically significant (χ2 =0.014,0.013,all P <0.05).Conclusions The incidence of boys with MB is higher than girls.CMB is the main histopathologic subtype in children over 3 years old.The primary tumor location involving the cerebellar vermis or cerebellar vermis and the fourth ventricle is higher in girls with MB.The primary tumor location involving the fourth ventricle,the fourth ventricle and other parts of the central nervous system,Cerebellar vermis and other parts of the central nervous system or other parts of the central nervous system is higher in boys with MB.

Objective To observe the influence of hemoperfusion(HP) on microinflammatory state and atherosclerosis in uremic patients .Methods Thirty‐six patients with uremia were randomly assigned into 2 groups ,18 cases in eath group .The hemo‐dialysis(HD) group took hemodialysis for 3 times per week ,4 h per time;the HP+ HD group took once HP per week on the basis of HD .The levels of C‐reactive protein(CRP) ,total cholesterol(TC) ,triglyceride(TG) ,urea nitrogen(BUN) and serum creatinine (Cr) were measured before therapy and in six months after therapy .The atherosclerotic plaque size was detected by ultrasound with fine resolution .Results The levels of CRP ,TG and TC after treatment in the HP+ HD group were significantly decreased com‐pared with those before treatment and the HD group (P<0 .05) .The number of therosclerotic plaques in the HP+ HD group had no increase .BUN and Cr had no statistical differences between the two groups(P>0 .05) .Conclusion HP can alleviate the inflam‐matory reaction and decrease the atherosclerosis occurrence .

Objective To study different test positions on vestibular evoked myogenic potentials (VEMPs) in youth ,and to find a suitable position and provide a guidance for clinical practice .Methods Thirty normal young vol-unteers were tested by vestibular evoked myogenic potentials ,using three different positions :supine with the head held straight up(SHU),supine with the head held up and turned away from the test ear(SHT),sitting with the head turned away from the test(SIT) ,the derivation rate ,latency and amplitude were analyzed .Results The deri-vation rate of SHU ,SHT and SIT were 100% ,100% and 63 .3% ,respectively .The derivation rate ,p13 ,n23 la-tency and p13 n23 inter-latency between SHU and SIT ,and between SHT and SIT had statistical differences (P<0 .05) .No statistical significant differences were found in derivation rate ,p13 ,n23 latency and p13n23 inter-latency between SHU and SHT (P>0 .05) .The amplitude was significantly different among the three positions (P<0 .05) . No statistical significant difference were found in derivation rate ,p13 ,n23 latency ,p13 n23 inter -latency and am-plitude between men and women of the three positions (P> 0 .05) .Conclusion The derivation rate of SHT was 100% with maximum amplitude .SHT is the most recommended position for clinical test in youth .The derivation rate of SHU was 100% ,and no statistical significant difference were found in p13 ,n23 latency and p13n23 inter-la-tency between SHU and SHT (P>0 .05) .SHU can be used in clinical test .SIT is not recommended for using in clinical test .Gender does not affect VEM Ps test .