Improved transient silencing of gene expression in the mosquito female Aedes aegypti

Gene silencing using RNA interference (RNAi) has become a widely used genetic technique to study gene function in many organisms. In insects, this technique is often applied through the delivery of dsRNA. In the adult female Aedes aegypti, a main vector of human-infecting arboviruses, efficiency of gene silencing following dsRNA injection varies greatly according to targeted genes. Difficult knockdowns using dsRNA can thus hamper gene function analysis. Here, by analysing silencing of three different genes in female Ae. aegypti (p400, ago2 and E75), we show that gene silencing can indeed be dsRNA sequence dependent but different efficiencies do not correlate with dsRNA length. Our findings suggest that silencing is likely also gene dependent, probably due to gene-specific tissue expression and/or feedback mechanisms. We demonstrate that use of high doses of dsRNA can improve knockdown efficiency, and injection of a transfection reagent along with dsRNA reduces the variability in efficiency between replicates. Finally, we show that gene silencing cannot be achieved using siRNA injection in Ae. aegypti adult females. Overall, this work should help future gene function analyses using RNAi in adult females Ae. aegypti, leading toward a better understanding of physiological and infectious processes.     

Diabetes-Related Factors and the Effects of Ticagrelor Plus Aspirin in the THEMIS and THEMIS-PCI Trials

BackgroundTHEMIS (The Effect of Ticagrelor on Health Outcomes in Diabetes Mellitus Patients Intervention Study) (n = 19,220) and its pre-specified THEMIS-PCI (The Effect of Ticagrelor on Health Outcomes in Diabetes Mellitus Patients Intervention Study-Percutaneous Coronary Intervention) (n = 11,154) subanalysis showed, in individuals with type 2 diabetes mellitus (median duration 10.0 years; HbA_1c 7.1%) and stable coronary artery disease without prior myocardial infarction (MI) or stroke, that ticagrelor plus aspirin (compared with placebo plus aspirin) produced a favorable net clinical benefit (composite of all-cause mortality, MI, stroke, fatal bleeding, and intracranial bleeding) if the patients had a previous percutaneous coronary intervention.ObjectivesIn these post hoc analyses, the authors examined whether the primary efficacy outcome (cardiovascular death, MI, stroke: 3-point major adverse cardiovascular events [MACE]), primary safety outcome (Thrombolysis In Myocardial Infarction–defined major bleeding) and net clinical benefit varied with diabetes-related factors.MethodsOutcomes were analyzed across baseline diabetes duration, HbA_1c, and antihyperglycemic medications.ResultsIn THEMIS, the incidence of 3-point MACE increased with diabetes duration (6.7% for ≤5 years, 11.1% for >20 years) and HbA_1c (6.4% for ≤6.0%, 11.8% for >10.0%). The relative benefits of ticagrelor plus aspirin on 3-point MACE reduction (hazard ratio [HR]: 0.90; p = 0.04) were generally consistent across subgroups. Major bleeding event rate (overall: 1.6%) did not vary by diabetes duration or HbA_1c and was increased similarly by ticagrelor across all subgroups (HR: 2.32; p < 0.001). These findings were mirrored in THEMIS-PCI. The efficacy and safety of ticagrelor plus aspirin did not differ by baseline antihyperglycemic therapy. In THEMIS-PCI, but not THEMIS, ticagrelor generally produced favorable net clinical benefit across diabetes duration, HbA_1c, and antihyperglycemic medications.ConclusionTicagrelor plus aspirin yielded generally consistent and favorable net clinical benefit across the diabetes-related factors in THEMIS-PCI but not in the overall THEMIS population.     

Effect of clopidogrel pretreatment on angiographic and clinical outcomes in patients undergoing primary percutaneous coronary intervention for ST-elevation acute myocardial infarction

Pretreatment with clopidogrel before elective primary percutaneous coronary intervention (PCI) has been shown to reduce ischemic complications. There are limited data about the value of clopidogrel pretreatment in the setting of PCI for ST-elevation myocardial infarction (STEMI). We aimed to examine the effect of clopidogrel preloading on angiographic and clinical outcomes in patients with STEMI who were treated with PCI. We conducted a prospective registry of all patients treated with primary PCI for STEMI from March 2003 to June 2006. Excluded were patients with cardiogenic shock. For the current analysis, patients (n = 292) were allocated into 2 groups. One group received clopidogrel loading dose before PCI (in the emergency department or coronary care unit, n = 165); the other,immediately after PCI (n = 127). TIMI myocardial perfusion (TMP) grade at the end of PCI and 30-day and 6-month clinical outcomes were assessed. Clinical characteristics were similar among the groups. However, patients pretreated with clopidogrel were more likely to receive aspirin and beta blockers before the current admission. TMP grade 3 occurred in a higher proportion of patients in the clopidogrel pretreatment group than in the no-pretreatment group (85% vs 71%, p = 0.01). Multivariate logistic regression analysis showed that clopidogrel pretreatment was associated with an odds ratio of 2.2 for TMP grade 3 (1.2 to 3.9, p = 0.01). Furthermore, the incidence of reinfarction at 30 days was lower in the pretreatment group (0% vs 3.2%, respectively, p = 0.04). In conclusion, these findings support the early use of clopidogrel in patients with STEMI who are treated with primary PCI.     

Prospective assessment after pediatric cardiac ablation: demographics, medical profiles, and initial outcomes

INTRODUCTION: A multicenter prospective study was designed and implemented to assess the short- and longer-term results and risks associated with radiofrequency (RF) ablation in children. METHODS AND RESULTS: Patients recruited for the study were aged 0 to 16 years with supraventricular tachycardia due to accessory pathways or AV nodal reentrant tachycardia (AVNRT), excluding patients with nontrivial congenital heart disease. A national registry also was established, and contributing centers were encouraged to enroll all pediatric patients, aged 0 to 21 years, undergoing ablation at their center. This report summarizes acute results of these procedures. For analysis, subjects were divided into three groups: the prospective cohort (n = 481), cohort-eligible registry participants (n = 504), and not cohort eligible registry participants (n = 1,776). Prospectively enrolled cohort patients were similar to cohort-eligible patients in terms of demographic and other patient characteristics. Overall success rates for RF ablation were high (95.7%), with higher success rates for left-sided and particularly left free-wall pathways (97.8%) than right free-wall pathways (90.8%). Complications of both electrophysiologic study and RF ablation were infrequent (4.2% and 4.0%, respectively), and there were no deaths. AV block was uncommon overall (1.2%) and was limited to ablation in AVNRT (2.1%) and septal accessory pathways (3.0%). CONCLUSION: Despite the multicenter and prospective design, the study demonstrates high success rates and low complication rates, which are comparable to prior single-center retrospective studies. These results may serve as the current best benchmark for expected results in the pediatric population, aged 0 to 16 years, both in terms of acute success rates and the occurrence of complications.     

Role of leisure-time physical activity in nonalcoholic fatty liver disease: a population-based study

Physical activity (PA) is commonly recommended for nonalchoholic fatty liver disease (NAFLD) patients. However, there is limited evidence on the independent role of PA in NAFLD. The aim of this study was to examine the association between PA and NAFLD. We conducted a cross-sectional study of a subsample (n = 375) of the Israeli National Health and Nutrition Survey. Exclusion criteria were any known etiology for liver disease. Participants underwent an abdominal ultrasound examination; biochemical tests, including leptin, adiponectin, and resistin; and the noninvasive biomarker SteatoTest and anthropometric evaluations. A semiquantitative food frequency questionnaire and a detailed PA questionnaire were administered. Three hundred forty-nine patients (52.7% men, 30.9% primary NAFLD) were included. The NAFLD group engaged in less aerobic, resistance, or other kinds of PA (P 相似文献   

Phenotype-genotype studies in kuru: Implications for new variant Creutzfeldt–Jakob disease

The PRNP polymorphic (methionine/valine) codon 129 genotype influences the phenotypic features of transmissible spongiform encephalopathy. All tested cases of new variant Creutzfeldt–Jakob disease (nvCJD) have been homozygous for methionine, and it is conjectural whether different genotypes, if they appear, might have distinctive phenotypes and implications for the future “epidemic curve” of nvCJD. Genotype-phenotype studies of kuru, the only other orally transmitted transmissible spongiform encephalopathy, might be instructive in predicting the answers to these questions. We therefore extracted DNA from blood clots or sera from 92 kuru patients, and analyzed their codon 129 PRNP genotypes with respect to the age at onset and duration of illness and, in nine cases, to detailed clinical and neuropathology data. Homozygosity at codon 129 (particularly for methionine) was associated with an earlier age at onset and a shorter duration of illness than was heterozygosity, but other clinical characteristics were similar for all genotypes. In the nine neuropathologically examined cases, the presence of histologically recognizable plaques was limited to cases carrying at least one methionine allele (three homozygotes and one heterozygote). If nvCJD behaves like kuru, future cases (with longer incubation periods) may begin to occur in older individuals with heterozygous codon 129 genotypes and signal a maturing evolution of the nvCJD “epidemic.” The clinical phenotype of such cases should be similar to that of homozygous cases, but may have less (or at least less readily identified) amyloid plaque formation.