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 study the effect of Jiedu-xiaozheng decoction on theUltrastructure changes and quantitative analysis of SGC-7901 in vitro and its mechanisms. Methods The compound prescription Jiedu-xiaozheng decoction was used to prepare serum containing drug. Serologic pharmacology methods was applied. The decoction was used to co-culture the gastric cells for24 h and 72 h, and the ultrastructure of tumor cells was observed by the transmission electron microscope. Then the parameters of the nucleus and mitochrondria were determined in SGC-7901 cells, including volume density(Vv) ,form factor PE( PE), average volume(V) ,length(L) average surrace area(S),contrasting to cytoplasma. The SIS powervision was applied to analyze their difference. Results Jiedu-xiaozheng decotion can result in reduced microvilli, deflated volume, decreased mitochondrion volume and reduced ridge. The volume density(Vv) ,form factor PE(PE) ,average volume(v) ,length (L) average surrace area(S) reduced in the 24 h group clearly in Jiedu-xiaozheng decoction group compared to control group. Conclusion Jiedu-xiaozheng decoction can significantly induce SGC-7901 cells apoptosis, exhibiting certain early ultrastructure changes such as marginated heterochromatin and mitochondrion pyknosis. The quantity analysis by electronic imaging system may objectively reveal the ultrastructural changes of cell nucleus and mitochondria.

Objective To investigate the influence of pinealectomy(Px)and melatonin (MLT) supplementation on CD4~+CD25~+Treg cells development and Foxp3 expression in rat thymus. Methods One hundred and twenty clean-grade male SD rats were divided into five groups: normal control group, sham pinealectomized group, pinealectomized group, Px +7.5 mg/(kg·d) MLT group, Px +15 mg/(kg·d) MLT group, and the thymus were taken out at the 4th week and the 8th week;Flow cytometric analysis was used to analyse the number of double positive cells in the thymus and peripheral blood;Semiquantitative RT-PCR and immunohistochemistry were applied to analyse Foxp3 expression of rat thymus. Results There was no difference of the number of CD4~+CD25~+ Treg cells in rat thymus between Px and normal/sham group, and the number increased dependently on time and dose after MLT supplementation. In rat peripheral blood the double positive cells significantly increased in models of Px at the 4th week, and then backed to normal level after MLT supplementation. The results showed no significant changes in all groups at the 8th weeek;At the 4th weeks, Foxp3 expression increased in the thymus of Px rats compared to nomal/sham group, which returned to normal level after MLT supplementation. On the other hand, Foxp3 expression showed no significant difference in all groups at the 8th weeek.Conclusion Px made no difference between the development of CD4~+CD25~+Treg cells in rat thymus, but resulted in significant increase of thymic output and Foxp3 expression. All the effects disappeared at the 8th week. MLT supplementation could reverse the abnormity.

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 .

The patients aged ≥ 60 years account for 70％ of Chinese population with colorectal cancer.However,with the increase of age,the treatment methods such as surgery,radiotherapy,chemotherapy become inappropriate and impeding factors for the self-care of the elderly.Several clinical trials show that only a part of the elderly,who are in good health condition,can get the clinical benefits from these therapies.Therefore,this review focused on the comprehensive treatments for elderly patients with colorectal cancer,then reached the best individualized treatment,so as to improve the survival and quality of life.

Objective:To explore the epidemiological characteristics of Streptococcus pyogenes, namely β-hemolytic Group A Streptococcus (GAS) in children in Shenzhen. Methods:Multilocus sequence typing (MLST) data on the epidemic clonal population of GAS infection in children in Shenzhen Children′s Hospital from January 2016 to December 2018 were retrospectively analyzed.In the present study, 32 GAS strains belonging to 7 different emm types were from 32 children′s with impetigo, cellulitis, scarlet fever, sepsis, pneumonia, obstructive sleep apnea hypopnea syndrome, bronchitis, allergy with rhinitis, buttock abscess, allergic purpura or pharyngeal tonsillitis, which were isolated from 23 throat swabs, 5 sputum samples, 3 pus and 1 blood.Using polymerase chain reaction technology, 7 pairs of allelic housekeeping genes ( gki, gtr, murI, mutS, recP, xpt and yqiL) of 32 GAS isolates were analyzed, and the target gene products were subjected to sequencing.Then the obtained gene sequences of each allele were submitted to the MLST database to obtain the allele profile.Finally, the allele profiles were introduced in the MLST database again to confirm the sequence typing (ST). Results:The GAS clone groups of emm 1.00 and its subtypes, emm 4.00, emm 12.00 and its subtypes, emm 22.00, emm 28.00, emm 75.00, and emm 89.00 belonged to the sequence typing ST28, ST39, ST36, ST46, ST52, ST49, and ST921, respectively. Conclusions:From 2016 to 2018, the MLST clone populations of GAS isolates causing infections in children in Shenzhen are classified as ST28, ST39, ST36, ST46, ST52, ST49 and ST921.

Objective:To investigate the correlation of the emm genotypes and virulence genes with the isolation sites of Group A Streptococcus (GAS). Methods:It was a retrospective study.The specimens were collected from children with impetigo in Beijing Children′s Hospital, Capital Medical University from 2006 to 2008 for GAS isolation and identification.A total of 24 GAS strains were isolated from 16 children with impetigo, among which 7 pairs of strains were isolated from the throat and skin of 7 children, and 1 pair of strains was isolated from the vulva and skin of one child, and the remaining 8 GAS strains were isolated from the skin pus samples of 8 children.Polymerase chain reaction was applied to detect the emm genotypes and 13 virulence genes ( speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa). The correlation of the emm genotypes and virulence genes with the isolation sites of GAS strains was analyzed. Results:In this study, four emm genotypes were detected, including emm1.0 (15/24), emm12.0 (4/24), emm22.0 (2/24) and emm160.0 (1/24), and one subtype emm12.19 (2/24) was detected as well.The carrying rates of 13 virulence genes speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were 58.3%, 100%, 91.7%, 100%, 50.0%, 12.5%, 54.2%, 66.7%, 16.7%, 25.0%, 12.5%, 100% and 91.7%, respectively.All strains carried 5 to 11 virulence genes and they all carried speB, speF and smeZ.There were significant differences in the carrying rate of speA and speJ among the strains with different emm genotypes (all P<0.05). There was no significant difference in the distribution of virulence genes between skin isolates and pharyngeal isolates, including the 5 pairs of strains carrying the emm1.0 genotype (all P>0.05). Conclusions:The distribution of virulence gene of GAS in children with impetigo is significantly correlated with the emm genotype, rather than the isolation site.

Group A Streptococcus (GAS) is a very important pathogen, especially for children.On a global scale, GAS is an important cause of morbidity and mortality.But the burden of disease caused by GAS is still unknown in China and also has not obtained enough attention.For this purpose, the expert consensus is comprehensively described in diagnosis, treatment and prevention of GAS diseases in children, covering related aspects of pneumology, infectiology, immunology, microbiology, cardiology, nephrology, critical care medicine and preventive medicine.Accordingly, the consensus document was intended to improve management strategies of GAS disease in Chinese children.