Circulating CCRR serves as potential novel biomarker for predicting acute myocardial infarction

Objective:Cold regions exhibit a high prevalence of cardiovascular disease,particularly acute myocardial infarction(AMI),which is one of the leading causes of death associated with cardiovascular conditions.Cardiovascular disease is closely linked to the abnormal expression of long non-coding RNA(lncRNA).This study investigates whether circulating levels of lncRNA cardiac conduction regulatory RNA(CCRR)could serve as a biomarker for AMI.Materials and methods:We measured circulating CCRR from whole blood samples collected from 68 AMI patients and 69 non-AMI subjects.An AMI model was established using C57BL/6 mice.Quantitative reverse transcription PCR(qRT-PCR)was used to assess CCRR expression.Exosomes were isolated from cardiomyocytes,and their characteristics were evaluated using electron microscope and nanoparticle tracking analysis.The exosome inhibitor GW4869 was employed to examine the effect of exosomal CCRR on cardiac function using echocardiography.Protein expression was detected using Western blot and immunofluorescence staining.Results:The circulating level of CCRR was significantly higher in AMI patients(1.93±0.13)than in non-AMI subjects(1.00±0.05,P<0.001).The area under the ROC curve(AUC)of circulating CCRR was 0.821.Similar changes in circulating CCRR levels were consistently observed in an AMI mouse model.Exosomal CCRR derived from hypoxia-induced cardiomyocytes and cardiac tissue after AMI were increased,a change that was reversed by GW4869.Additionally,CCRR-overexpressing exosomes improved cardiac function in AMI.Conclusion:Circulating lncRNA CCRR is a potential predictor of AMI.Exosomal CCRR plays a role in the communication between the heart and other organs through circulation.

Prevalence of antifolate drug resistance markers in Plasmodium vivax in China

The dihydrofolate reductase(dhfr)and dihydropteroate synthetase(dhps)genes of Plasmodium vivax,as antifolate resistance-associated genes were used for drug resistance surveillance.A total of 375 P.vivax isolates collected from different geographical locations in China in 2009–2019 were used to sequence Pvdhfr and Pvdhps.The majority of the isolates harbored a mutant type allele for Pvdhfr(94.5%)and Pvdhps(68.2%).The most predominant point mutations were S117T/N(77.7%)in Pvdhfr and A383G(66.8%)in Pvdhps.Amino acid changes were identified at nine residues in Pvdhfr.A quadruple-mutant haplotype at 57,58,61,and 117 was the most frequent(57.4%)among 16 distinct Pvdhfr haplotypes.Mutations in Pvdhps were detected at six codons,and the double-mutant A383G/A553G was the most prevalent(39.3%).Pvdhfr exhibited a higher mutation prevalence and greater diversity than Pvdhps in China.Most isolates from Yunnan carried multiple mutant haplotypes,while the majority of samples from temperate regions and Hainan Island harbored the wild type or single mutant type.This study indicated that the antifolate resistance levels of P.vivax parasites were different across China and molecular markers could be used to rapidly monitor drug resistance.Results provided evidence for updating national drug policy and treatment guidelines.

An innovative three-layer strategy in response to a quartan malaria outbreak among forest goers in Hainan Island,China:a retrospective study

Background:An outbreak of Plasmodium malariae infection among forest goers in Sanya City of Hainan Island,China was reported in 2015.In response to this outbreak,an innovative three-layer strategy(TLS)targeted forest goers was adapted based on the 1-3-7 approach.Main text:Key elements of TLS are:(i)The village with fve malaria cases and adjacent villages were set as the frst layer.All residents including forest goers were taken as the high-risk population(HRP).Active case detection(ACD)by blood smear microscopy and PCR was selected as the primary measure,and passive case detection(PCD)as complementary measure.One case was identifed under TLS implementation.(ii)The township with cases(Gaofeng Town)and the nearby towns were chosen as the second layer.Only forest goers were screened by ACD,while PCD as a routine screening method.7831 blood smears collected by ACD and PCD and tested with negative results.(iii)The city with cases(Sanya City)and others 12 counties/county-level cities were selected as the third layer.Malaria cases were monitored passively.A total of 77,555 blood slides were screened by PCD with zero positive sample.For each layer,the malaria vector mosquitoes were monitored using light traps,cattle-baited/human-bait traps.Anopheles minimus(dominant species),An.sinensis and An.dirus were captured.Vector control measures mainly include insecticide residual spraying and long-lasting insecticide nets.The capacity of clinicians,public health practitioners and laboratory technicians has been improved through training.During 2016‒2018,TLS and chemoprophylaxis were implemented in the same areas.In the frst layer,all residents were monitored by ACD,and malaria chemoprophylaxis were distributed,89.5%of forest goers were using chemoprophylaxis against malaria.The blood smears(3126 by ACD plus 1516 by PCD)were with zero positive results.Chemoprophylaxis and ACD were ofered to forest goers once a year,and PCD in residents as a complementary measure in the second and third layer,77.8%and 95.1%of forest goers received chemoprophylaxis.In each layer,vector surveillance and control of malaria and trainings for medical staf Conclusions:TLS was efective in blocking the outbreak by P.malariae among forest goers in Hainan in malaria elimination stage.However,whether it could prevent the malaria resurgence in the post-elimination phase needs to be further assessed.