简介:AbstractBackground:To detect acute schistosomiasis, low-intensity infections, or to verify the success of treatment with praziquantel, highly sensitive test methods are required. The aim of this study was therefore to demonstrate the performance of Schistosoma mansoni specific DNA detection in serum and urine using real-time polymerase chain reaction (PCR) in an endemic area before and after treatment.Methods:The study pursued a 1-week and 20-weeks longitudinal design with a treatment intervention among 36 study participants aged 18 to 70 years in the community of Kayenze, a fishing village in Ilemela district on the southern shore of Lake Victoria in north-western Tanzania between February and June 2018. Blood, urine and stool samples were collected from each participant to diagnose Schistosoma mansoni infection before and two times after treatment with praziquantel using serum-and urine based real-time PCR, point-of-care circulating cathodic antigen (POC-CCA) rapid diagnostic test and the microscopic Kato-Katz (KK) method. Kappa coefficient (κ) was used to estimate the agreement between these diagnostic tests compared to a combined "gold standard" of positive results by serum-based real-time PCR and/or positive egg counts determined by KK. Kendall’s Tau rank correlation was used to examine the relationship between cycle threshold (Ct)-values and egg counts and the Wilcoxon signed-rank test was used to compare the median Ct-values of the different examination time points.Results:By using the combined "gold standard" of the parasitological Kato-Katz test and/or serum-based real-time PCR, a S. mansoni prevalence of 77.1% could be determined at baseline. In terms of sensitivity, serum-based realtime PCR (96.3%) and POC-CCA assay (77.8%) showed the highest results. The detection of DNA from urine samples showed the lowest sensitivity (33.3%). Treatment with praziquantel resulted in a significantly reduced prevalence of S. mansoni. No infection could be detected by Kato-Katz, with the POC-CCA test only 33.3%. The analysis of the median Ct values over time (which were determined by the serum-based real-time PCR) showed that the Ct decreases significantly shortly after treatment (from 30.3 to 28) and increases above baseline level (34.9) three months later.Conclusions:The data presented here show that the serum-based real-time PCR exhibits excellent diagnostic accuracy, in contrast to the use of urine as sample material for S. mansoni DNA detection. However, as circulating DNA does not necessarily reflect the persistence of living worms in schistosomiasis, this method is less well suited to verify the success of treatment with praziquantel.
简介:Inrecentyears,therehavebeensignificantadvancesinwearable,mobile,dry-electrodeelectroencephalography(EEG)systems.Theseareyieldingexcitingnewpossibilitiesforscientificresearch,clinicaldiagnosticsandtherapeutics,andbrain-computerinterfaces(BCI)outsidetheclinicorlaboratory.However,thesesystemshavebeenlimitedtoahandfulofchannelsmostlyforapplicationsof
简介:AbstractFever and rash illnesses (FRIs) are a series of common diseases with fever and rashes as clinical manifestations, most of which are caused by viral infection. The rashes of FRIs are generally nonspecific; therefore it is difficult to identify FRI-associated viruses solely based on clinical symptoms. To achieve rapid and accurate identification of FRI pathogens, a multiplex one-step real-time reverse transcription-polymerase chain reaction (RT-PCR) assay was developed and evaluated in this study. Primers and probes were selected for the detection of measles virus (MeV), rubella virus (RV), human enterovirus (EV), varicella-zoster virus (VZV), dengue virus (DENV), human parvovirus B19 (B19), Epstein-Barr virus (EBV), and human herpes virus 6 (HHV-6), which cover the most common pathogenic viruses of FRIs. Detection of the eight FRI-associated viruses, which was divided into two groups/tubes, was simultaneously performed under universal optimized reaction conditions in multiplex one-step real-time RT-PCR assay. The multiplex realtime RT-PCR showed high sensitivity and specificity in detecting the eight FRI-associated viruses. The limits of detection (LODs) for the eight viruses were in the range of 47–177 copies/reaction, and no cross reactions for the eight FRI-associated viruses were found in the multiplex assay. In addition, the results of the multiplex real-time RT-PCR assay were consistent with the results of a monoplex real-time RT-PCR assay and sequencing for clinical specimens obtained from FRI patients. With its advantages of high efficiency and rapid and accurate diagnosis, multiplex real-time RT-PCR was very feasible for the early diagnosis of FRI pathogenic viruses and would be of great help for the proper treatment, monitoring, and initiation of preventive measures for FRI cases.
简介:ObjectivesToassesstherelationshipbetweenpeakoxygenconsumption(PVO2)andtheambulationdistanceinsix-minutewalktest(6MWT)amongthehealthysubjects.MethodsThe51healthysubjectswererecruitedforthesix-minutewalktest.Dataofpulmonarygasexchangebreathbybreath,suchasVO2,VCO2werereal-timemeasuredwithwirelessremotesensingK4B2,sotostudytherelationshipbetweenpeakoxygenuptakeandtheambulationdistance.ResultsItwasnoticedthattherewasapositivelinearcorrelationbetweentheambulationdistanceandPVO2(r=0.619,P<0.001)insix-minutewalktest.Theregressionequationwassetup(VO2/kg=0.05D-6.331,P<0.001).PVO2>PVCO2,R<1werefound,whichsuggestedthat6MWTwasatestbelowanaerobicthreshold.ConclusionsTherewasacloselypositivelinearcorrelationbetweentheambulationdistanceandPVO2,whichissafety,convenientandvaluablefortheevaluationofcardiopulmonaryfunctionandthetreatmentofcardiopulmonaryrehabilitation.
简介:AbstractLung cancer is one of the leading causes of all cancer-related deaths. Circulating tumor DNA (ctDNA) is released from apoptotic and necrotic tumor cells. Several sensitive techniques have been invented and adapted to quantify ctDNA genomic alterations. Applications of ctDNA in lung cancer include early diagnosis and detection, prognosis prediction, detecting mutations and structural alterations, minimal residual disease, tumor mutational burden, and tumor evolution tracking. Compared to surgical biopsy and radiographic imaging, the advantages of ctDNA are that it is a non-invasive procedure, allows real-time monitoring, and has relatively high sensitivity and specificity. Given the massive research on non-small cell lung cancer, attention should be paid to small cell lung cancer.
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简介:BackgroundTwo-dimensionalspeckletrackingimaging(2D-STI)andreal-timethree-dimensionalechocardiography(RT-3DE)havemoreadvantagesinevaluatingleftventricular(LV)systolicdyssynchronythantraditionalechocardiographictechniques.ThestudyaimedtoevaluateLVdyssynchronyparametersbyboth2D-STIandRT-3DE,andthecorrelationbetweenthesetwotechniques.MethodsAtotalof43chronicheartfailure(CHF)patientsand27healthyvolunteerswereenrolled.Therewere23dyssynchronyparametersselectedtoevaluateleftventricularsystolicsynchronization,involving15from2D-STIand8fromRT-3DE.ResultsFewofthedyssynchronyparametersshowednegativecorrelationswithLVejectionfraction(LVEF)intheCHFgroup.Thedifferencebetweentimetopeak-systolicradialstrainoftheanteroseptalandposteriorsegmentsatthelevelofpapillarymuscles[AS-P(RS)]from2D-STIshowedpositivecorrelationswithpartsoftheparametersfromRT-3DE(P<0.05).ConclusionsLVsystolicdysfunctiondoesnotcorrelatewithdyssynchrony.Moreover,thereisaweakassociationbetween2D-STIandRT-3DEinassessmentofleftventriculardyssynchrony.
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简介:AbstractBackground:With the ongoing worldwide coronavirus disease 2019 (COVID-19) pandemic, an increasing number of viral variants are being identified, which poses a challenge for nucleic acid-based diagnostic tests. Rapid tests, such as real-time reverse transcription-polymerase chain reaction (rRT-PCR), play an important role in monitoring COVID-19 infection and controlling its spread. However, the changes in the genotypes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants may result in decreased sensitivity of the rRT-PCR assay and it is necessary to monitor the mutations in primers and probes of SARS-CoV-2 detection over time.Methods:We developed two rRT-PCR assays to detect the RNA-dependent RNA polymerase (RdRp) and nucleocapsid (N) genes of SARS-CoV-2. We evaluated these assays together with our previously published assays targeting the ORF1ab and N genes for the detection and confirmation of SARS-CoV-2 and its variants of concern (VOCs). In addition, we also developed two rRT-PCR assays (S484K and S501Y) targeting the spike gene, which when combined with the open reading frames (ORF)1ab assay, respectively, to form duplex rRT-PCR assays, were able to detect SARS-CoV-2 VOCs (lineages B.1.351 and B.1.1.7).Results:Using a SARS-CoV-2 stock with predetermined genomic copies as a standard, the detection limit of both assays targeting RdRp and N was five copies/reaction. Furthermore, no cross-reactions with six others human CoVs (229E, OC43, NL63, HKU1, severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus) were observed using these assays. In addition, the S484K and S501Y assays were combined with the ORF1ab assay, respectively.Conclusions:Four rRT-PCR assays (RdRp, N, S484K, and S501Y) were used to detect SARS-CoV-2 variants, and these assays were shown to be effective in screening for multiple virus strains.
简介:AbstractObjective:To test the feasibility of a real time miniature endoscope system for imaging the nasopharynx.Study design:Preclinical assessment on skull model and cadaver.Methods:A 3.5 mm miniature endoscope was fabricated and the image capture of the nasopharynx was investigated by positioning the miniature camera system at the posterior free edge of the vomer bone. Wireless real time transmission of the images and quality was tested in a skull model. Next, three nasopharyngeal surveillance miniature camera system were developed for possible clinical translation. Two prototypes were anchored on the nasal septum and the last prototype was designed using a patient self-administered surveillance process. These prototypes were tested for feasibility on both the phantom skull and cadaveric model. Risk assessments were also performed to assess risk, safety and validate the reliability of the material utilized for clinical translation.Results:Insertion and anchorage of the miniature surveillance endoscope prototypes at the vomer bone were feasible on all 3 prototypes. The quality of captured images was reasonable and miniaturized camera was responsive to pan at different angles so that the entire nasopharynx may be surveyed. Risk assessments on the material such as pull out test, breaking force analysis, finite element test and tensile strength test were reliable for possible clinical translation.Conclusions:Real time miniature endoscope system for surveillance of nasopharyngeal cancer is feasible. Clinical translation of this technology was possible but requires further refinement in enhancing image quality and wireless transmission of the captured images.
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简介:AbstractBackground:As COVID-19 makes its way around the globe, each nation must decide when and how to respond. Yet many knowledge gaps persist, and many countries lack the capacity to develop complex models to assess risk and response. This paper aimed to meet this need by developing a model that uses case reporting data as input and provides a four-tiered risk assessment output.Methods:We used publicly available, country/territory level case reporting data to determine median seeding number, mean seeding time (ST), and several measures of mean doubling time (DT) for COVID-19. We then structured our model as a coordinate plane with ST on the x-axis, DT on the y-axis, and mean ST and mean DT dividing the plane into four quadrants, each assigned a risk level. Sensitivity analysis was performed and countries/territories early in their outbreaks were assessed for risk.Results:Our main finding was that among 45 countries/territories evaluated, 87% were at high risk for their outbreaks entering a rapid growth phase epidemic. We furthermore found that the model was sensitive to changes in DT, and that these changes were consistent with what is officially known of cases reported and control strategies implemented in those countries.Conclusions:Our main finding is that the ST/DT Model can be used to produce meaningful assessments of the risk of escalation in country/territory-level COVID-19 epidemics using only case reporting data. Our model can help support timely, decisive action at the national level as leaders and other decision makers face of the serious public health threat that is COVID-19.
简介:1985年Cetus公司的Mullis发明的聚合酶链反应(PolymeraseChainReaction,PCR)是现代分子生物学研究中的一项非常重要的技术,它可在短时间内在试管中获得数百万特异DNA序列的拷贝,从而很容易地对目的基因进行分析、鉴定以及其它操作。这一技术现已广泛应用于生物学的各研究领域。PCR的定量实质是核酸的体外扩增,当人们利用技术扩增出大量的特异DNA序列后,还必须对这些PCR产物进行定性或定量检测,特别是临床检验中,定量分析PCR产物可以为临床诊断、疗效观察等提供更为准确的信息。另外,在研究基因的表达调控研究中,经常利用RT-PCR定量检测某一特定的转录mRNA,因此,建立灵敏、准确、重复性好的PCR产物定量检测法是目前PCR及其相关技术研究的特点,电是定量PCR技术的基础。本文将对这一技术近年来的研究进展状况作一简要综述。