Mesenchymal stem cell-derived exosomes inhibit the VEGF-A expression in human retinal vascular endothelial cells induced by high glucose

AIM: To determine the effect of exosomes derived from human umbilical cord blood mesenchymal stem cells (hUCMSCs) on the expression of vascular endothelial growth factor A (VEGF-A) in human retinal vascular endothelial cells (HRECs). METHODS: Exosomes were isolated from hUCMSCs using cryogenic ultracentrifugation and characterized by transmission electron microscopy, Western blotting and nanoparticle tracking analysis. HRECs were randomly divided into a normal control group (group A), a high glucose model group (group B), a high glucose group with 25 μg/mL (group C), 50 μg/mL (group D), and 100 μg/mL exosomes (group E). Twenty-four hours after coculture, the cell proliferation rate was detected using flow cytometry, and the VEGF-A level was detected using immunofluorescence. After coculture 8, 16, and 24h, the expression levels of VEGF-A in each group were detected using PCR and Western blots. RESULTS: The characteristic morphology (membrane structured vesicles) and size (diameter between 50 and 200 nm) were observed under transmission electron microscopy. The average diameter of 122.7 nm was discovered by nanoparticle tracking analysis (NTA). The exosomal markers CD9, CD63, and HSP70 were strongly detected. The proliferation rate of the cells in group B increased after 24h of coculture. Immunofluorescence analyses revealed that the upregulation of VEGF-A expression in HRECs stimulated by high glucose could be downregulated by cocultured hUCMSC-derived exosomes (F=39.03, P<0.01). The upregulation of VEGF-A protein (group C: F=7.96; group D: F=17.29; group E: F=11.89; 8h: F=9.45; 16h: F=12.86; 24h: F=42.28, P<0.05) and mRNA (group C: F=4.137; group D: F=13.64; group E: F=22.19; 8h: F=7.253; 16h: F=16.98; 24h: F=22.62, P<0.05) in HRECs stimulated by high glucose was downregulated by cocultured hUCMSC-derived exosomes (P<0.05). CONCLUSION: hUCMSC-derived exosomes downregulate VEGF-A expression in HRECs stimulated by high glucose in time and concentration dependent manner.     

Inclusion of CYP3A5 genotyping in a nonparametric population model improves dosing of tacrolimus early after transplantation

Following organ engraftment, initial dosing of tacrolimus is based on recipient weight and adjusted by measured C₀ concentrations. The bioavailability and elimination of tacrolimus are affected by the patients CYP3A5 genotype. Prospective data of the clinical advantage of knowing patient's CYP3A5 genotype prior to transplantation are lacking. A nonparametric population model was developed for tacrolimus in renal transplant recipients. Data from 99 patients were used for model development and validation. A three‐compartment model with first‐order absorption and lag time from the dosing compartment described the data well. Clearances and volumes of distribution were allometrically scaled to body size. The final model included fat‐free mass, body mass index, hematocrit, time after transplantation, and CYP3A5 genotype as covariates. The bias and imprecision were 0.35 and 1.38, respectively, in the external data set. Patients with functional CYP3A5 had 26% higher clearance and 37% lower bioavailability. Knowledge of CYP3A5 genotype provided an initial advantage, but only until 3‐4 tacrolimus concentrations were known. After this, a model without CYP3A5 genotype predicted just as well. The present models seem applicable for clinical individual dose predictions but need a prospective evaluation.     

Long‐Term Belatacept Exposure Maintains Efficacy and Safety at 5 Years: Results From the Long‐Term Extension of the BENEFIT Study

The Belatacept Evaluation of Nephroprotection and Efficacy as First‐line Immunosuppression Trial randomized patients receiving a living or standard criteria deceased donor kidney transplant to a more (MI) or less intensive (LI) regimen of belatacept or cyclosporine A (CsA). The 5‐year results of the long‐term extension (LTE) cohort are reported. A total of 456 (68.5% of intent‐to‐treat) patients entered the LTE at 36 months; 406 patients (89%) completed 60 months. Between Months 36 and 60, death occurred in 2%, 1% and 5% of belatacept MI, belatacept LI and CsA patients, respectively; graft loss occurred in 0% belatacept and 2% of CsA patients. Acute rejection between Months 36 and 60 was rare: zero belatacept MI, one belatacept LI and one CsA. Rates for infections and malignancies for Months 36–60 were generally similar across belatacept groups and CsA, respectively: fungal infections (14%, 15%, 12%), viral infections (21%, 18%, 16%) and malignancies (6%, 6%, 9%). No new posttransplant lymphoproliferative disorder cases occurred after 36 months. Mean calculated GFR (MDRD, mL/min/1.73 m²) at Month 60 was 74 for belatacept MI, 76 for belatacept LI and 53 for CsA. These results show that the renal function benefit and safety profile observed in belatacept‐treated patients in the early posttransplant period was sustained through 5 years.     

《人感染H7N9禽流感诊疗方案(2013年第2版)》解读

2013年2月以来在我国上海、安徽、江苏、浙江、北京和河南省市相继发生H7N9禽流感,截至2013年4月21日16时,全国H7N9禽流感确诊患者102例,其中20例死亡,病死率为19.6％.党中央、国务院和地方政府各级领导高度重视,全国省、市党政领导密切关注疫情进展,迅速启动应急响应,切实做好防控工作.国家卫生和计划生育委员会(以下简称卫计委)疫情防控领导小组强调必须遵循"依法、科学、规范、统一"的原则,按照"有力、有序、有效、有度"和"早发现、早报告、早诊断、早治疗"的防控方针,扎实做好全国疫情防控工作[1],并发布关于印发《人感染H7N9禽流感诊疗方案(2013年第2版)》(以下简称诊疗方案)[2].现对《诊疗方案》的病原学、流行病学、临床表现、诊断以及防治等问题作一解读.     

Infection of Chickens Caused by Avian Influenza Virus A/H5N1 Delivered by Aerosol and Other Routes

This study presents results of the study of infectivity of avian influenza virus (AIV) A subtype H5N1 strains isolated from agricultural birds across the territory of the Russian Federation and CIS countries. The results of the susceptibility of chickens to the AIV isolates delivered by the aerosol route and the dissemination of the virus in the organs of infected birds are presented. As was observed, the sensitivity of birds to AIV by the aerosol route of infection is 30 times higher than by intranasal route, 500 times higher than by the oral route and 10 000 times higher than by the intragastric route of infection, which is indicative of higher permissivity of respiratory organs to AIV. The highest titres of AIV A subtype H5N1(A/Chicken/Kurgan/05/2005 strain) in aerosol‐infected chickens were found in nasal cavity mucosa, lungs, cloaca, serum and kidney, where viable virus accumulation was detected by 18 h post‐infection (p.i.). The highest virus titres were observed 54 h p.i. in lungs, serum and kidney, reaching the value of 8.16 lg EID₅₀/g(ml) in the lungs. The results showed that birds infected by the aerosol route developed higher titres of virus than those infected by other routes.     

Detecting viruses by using salivary diagnostics

BackgroundDiagnostics that involve the use of oral fluids have become increasingly available commercially in recent years and are of particular interest because of their relative ease of use, low cost and noninvasive collection of oral fluid for testing.Types of Studies ReviewedThe authors discuss the use of salivary diagnostics for virus detection with an emphasis on rapid detection of infection by using point-of-care devices. In particular, they review salivary diagnostics for human immunodeficiency virus, hepatitis C virus and human papillomavirus. Oral mucosal transudate contains secretory immunoglobulin (Ig) A, as well as IgM and IgG, which makes it a good source for immunodiagnostic-based devices.Clinical ImplicationsBecause patients often visit a dentist more regularly than they do a physician, there is increased discussion in the dental community regarding the need for practitioners to be aware of salivary diagnostics and to be willing and able to administer these tests to their patients.