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ABSTRACT Background: The long-term effects of schistosomiasis on the glomerulus may contribute to the development of chronic kidney disease. This study aimed to investigate baseline Schistosoma mansoni-Circulating Anodic Antigen (CAA) levels and their association with kidney biomarkers related to podocyte injury and inflammation in long-term follow-up after praziquantel (PZQ) treatment. Methods: Schistosoma infection was diagnosed by detecting CAA in urine using a quantitative assay based on lateral flow using luminescent up-converting phosphor reporter particles. A cutoff threshold of 0.1 pg/mL CAA was used to diagnose Schistosoma infection (baseline) in a low-prevalence area in Ceará, Northeast, Brazil. Two groups were included: CAA-positive and CAA-negative individuals, both of which received a single dose of PZQ at baseline. Urinary samples from 55 individuals were evaluated before (baseline) and at 1, 2, and 3 years after PZQ treatment. At all time points, kidney biomarkers were quantified in urine and adjusted for urinary creatinine levels. Results: CAA-positive patients had increased baseline albuminuria and proteinuria and showed greater associations between kidney biomarkers. CAA levels correlated only with Vascular Endothelial Growth Factor (VEGF) (podocyte injury) levels. Increasing trends were observed for malondialdehyde (oxidative stress), monocyte chemoattractant protein-1 (inflammation marker), and VEGF. In the follow-up analysis, no relevant differences were observed in kidney biomarkers between the groups and different periods. Conclusions: S. mansoni-infected individuals presented subclinical signs of glomerular damage that may reflect podocyte injury. However, no causal effect on long-term renal function was observed after PZQ treatment.
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Objective To make portable the detector for up-converting phosphor (UCP) immune lateral flow assay portable and increase the test precision by developing an area CCD-based detection system for UCP immune lateral flow assay.Methods The excitation light source was a 980 nm and 300 mW laser diode.In order to decrease the error induced by the un-uniformity of laser irradiation,a uniformity mirror was inserted in the beam and a calibration algorithm was optimized.The residual error from the un-uniformity irradiation was less than 1％.Results Thanks to the adjustability of the exposure time,the dynamic range of detection of the system was as high as 106 dB.The repeat test error for the very low signal was 1％ (variation coefficient).The linear correlation coefficient between the tested T/C value and sample concentration was 0.998.Conclusion Compared to is traditional instrument,this detection system is static,portable and highly precise.
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Objective The detection results of two methods of quantitative methods and blood culture method were compared to explore the value of quantitative detection of serum procalcitonin.Methods From February 2014 to January 2015,the clinical data of 192 patients who were tested for two quantitative detection and blood culture were collected at the same time,and the results were eligible analyzed.One of the two quantitative detection methods was the electrochemical luminescence,and the other was the up-converting phosphor method.Results Compared with the result of blood culture,the positive rate was significantly higher in electrochemical luminescence and the up-con-verting phosphor method (χ2 =70.531,43.671,all P<0.05).The positive rates of up-converting phosphor and electrochemical luminescence were 66.1% and 75.5% respectively, and the difference between two quantitative methods was also statistically significant (χ2 =5.297,P<0.05).Method of electrochemical luminescence tested on higher sensitivity.When the level of PCT was less than threshold,for method of the electrochemical luminescence,the sensitivity on the blood culture was 93.7%,the specificity was 33.3%,the positive predictive value was 40.7%,the negative predictive value was 91.5%,the area under ROC curve was 0.628.For method of up-converting phosphor, the sensitivity on the blood culture was 90.5%,the specificity was 46.5%,the positive predictive value was 45.7%, the negative predictive value was 90.7%,the area under ROC curve was 0.554.Conclusion The electrochemical luminescence detection method of serum procalcitonin was better than up -converting phosphor method and blood culture.The electrochemical luminescence method which makes rapidly qualitative and accurately quantitative detec-tion,can give early diagnosis,medication guide in a short time,and predict the prognosis of disease.
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Objective To develop an up-converting phosphor technology based lateral flow (UPT-LF) assay for rapid detection of Salmonella paratyphi A, S.paratyphi B, Escherichia coli O157 ∶H7 and Vibrio parahaemolyticus. Methods With up-converting phosphor nano-particles ( UCP-NPs ) as the bio-marker, four double-antibody-sandwich mode based UPT-LF strips for detecting the above mentioned four pathogens were prepared respectively and their sensitivi-ty, accuracy, linearity and specificity were evaluated .Furthermore, the feasibility of detecting bacteria in food samples was evaluated by different food samples artificially contaminated with less than 10 CFU target pathogens .Results The sensitivi-ty of UPT-LF assays for four pathogens was 105 ~106 CFU/ml with excellent specificity .The four strips had a good linear response with the linear fitting coefficient of determination (r) for each target pathogen ranging from 0.985 to 0.996.The positive rate of detecting pathogens from samples was acceptable .Conclusion The four developed UPT-LF strips provide a new choice for rapid , specific and sensitive and quantitative detection of S.paratyphi A , S.paratyphi B, E.coli O157∶H7 and V.parahemolyticus.
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Objective To develop an up-converting phosphor technology-based lateral-flow ( UPT-LF) assay for rapid detection of Listeria monocytogenes, named LM -UPT-LF.Methods Monoclonal antibodies against p 60, which was the specific virulence factor of L.monocytogenes,were prepared and covalently conjugated with up-converting phosphor nanopar-ticles (UCP-NPs) as bio-label.Then, LM-UPT-LF was established with double-antibody sandwich mode-based LF assay. Detection performance , including sensitivity and specificity , was evaluated .Results The samples with absolute contamina-ted amount of L.monocytogenes cells <10, 10-99, and 100-1000 cfu could be significantly detected as positive after in-cubation at 20 h, 18 h, and 16 h, respectively.Other 13 kinds of food-borne pathogens with concentration of 109 cfu/ml did not caused any non-specific reaction .Conclusion The established LM-UPT-LF assay could detect L.monocytogenes with high sensitivity , specificity and simplicity and provides an alternative method for food safety control .
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Objective To develop and evaluate an up-converting phosphor technology-based lateral flow assay ( UPT-LF) for detection of aflatoxin M1(AFM1) in milk powder and milk.Methods AFM1-UPT-LF was established with up-converting phosphor ( UCP) nano-particles as the bio-label of competitive mode based LF assay .Sensitivity, quantitative ability and precision were evaluated using simulated AFM 1-postive samples with serial standard concentrations .The qualita-tive and quantitative detection performance of AFM 1-UPT-LF was evaluated with reference to liquid chromatography-mass spectrography ( LC-MS) to detect samples of milk powder and milk simultaneously .Results AFM1-UPT-LF could conduct qualitative and quantitative detection without sample pretreatment within 20 min.The detection limit of AFM1-UPT-LF reached 0.1 μg/kg in milk powder and 0.3 μg/L in milk.There was good linearity ranging from 0.1 to 0.7 μg/kg and 0.3 to 0.7 μg/L for milk powder and milk, respectively.The sensitivity, specificity and receiver operating characteristic ( ROC) area under the curve ( AUC) of AFM1-UPT-LF for qualitative result could meet the need of national standards for AFM1 limit in dairy products.After statistical analysis, there was no significant difference (milk powder: t=0.66, P>0.05;milk:t=1.01, P>0.05) between AFM1-UPT-LF and LC-MS for quantitative detection .Conclusion The good qualitative and quantitative detection performance of AFM 1-UPT-LF for milk powder and milk makes possible on-site rapid detection of AFM1 in dairy products quantitatively .