Current Issue : July - September Volume : 2016 Issue Number : 3 Articles : 6 Articles
This study aims at developing a simulation system that predicts the optimal study design for attaining tracer steady-state conditions\nin brain and blood rapidly. Tracer kinetics was determined from bolus studies and used to construct the system. Subsequently,\nthe system was used to design inputs for bolus infusion (BI) or programmed infusion (PI) experiments. Steady-state quantitative\nmeasurements can be made with one short scan and venous blood samples. The GABAA receptor ligand [11C]Flumazenil (FMZ)\nwas chosen for this purpose, as it lacks a suitable reference region. Methods. Five bolus [11C]FMZ-PET scans were conducted, based\non which population-based PI and BI schemes were designed and tested in five additional healthy subjects. The design of a PI was\nassisted by an offline feedback controller. Results. The system could reproduce the measurements in blood and brain. With PI,\n[11C]FMZ steady state was attained within 40 min, which was 8 min earlier than the optimal BI (B/I ratio = 55 min). Conclusions.\nThe system can design both BI and PI schemes to attain steady state rapidly. For example, subjects can be [11C]FMZ-PET scanned\nafter 40 min of tracer infusion for 40 min with venous sampling and a straight-forward quantification. This simulation toolbox is\navailable for other PET-tracers....
Background: It is difficult to discriminate healthy subjects and patients with Parkinson disease (PD) or Parkinson\ndisease dementia (PDD) by assaying plasma �±-synuclein because the concentrations of circulating �±-synuclein in the\nblood are almost the same as the low-detection limit using current immunoassays, such as enzyme-linked immunosorbent\nassay. In this work, an ultra-sensitive immunoassay utilizing immunomagnetic reduction (IMR) is developed.\nThe reagent for IMR consists of magnetic nanoparticles functionalized with antibodies against �±-synuclein and\ndispersed in pH-7.2 phosphate-buffered saline. A high-Tc superconducting-quantum-interference-device (SQUID)\nalternative-current magnetosusceptometer is used to measure the IMR signal of the reagent due to the association\nbetween magnetic nanoparticles and �±-synuclein molecules.\nResults: According to the experimental �±-synuclein concentration dependent IMR signal, the low-detection\nlimit is 0.3 fg/ml and the dynamic range is 310 pg/ml. The preliminary results show the plasma �±-synuclein for\nPD patients distributes from 6 to 30 fg/ml. For PDD patients, the concentration of plasma �±-synuclein varies from\n0.1 to 100 pg/ml. Whereas the concentration of plasma �±-synuclein for healthy subjects is significantly lower\nthan that of PD patients.\nConclusions: The ultra-sensitive IMR by utilizing antibody-functionalized magnetic nanoparticles and high-Tc SQUID\nmagnetometer is promising as a method to assay plasma �±-synuclein, which is a potential biomarker for discriminating\npatients with PD or PDD....
Background. This work examines the occurrence of interval colorectal cancers (CRCs) in the Ontario ColonCancerCheck (CCC)\nprogram. We define interval CRC as CRC diagnosed within 2 years following normal guaiac fecal occult blood testing (gFOBT).\nMethods. Persons aged 50ââ?¬â??74 who completed a baseline CCC gFOBT kit in 2008 and 2009, without a prior history of CRC, or recent\ncolonoscopy, flexible sigmoidoscopy, or gFOBT, were identified. Rates of CRC following positive and normal results at baseline and\nsubsequent gFOBT screens were computed and overall survival was compared between those following positive and normal results.\nResults. Interval CRC was diagnosed within 24 months following the baseline screen among 0.16% of normals and following the\nsubsequent screen among 0.18% of normals. Interval cancers comprised 38.70% of CRC following the baseline screen and 50.86%\nfollowing the subsequent screen. Adjusting for age and sex, the hazard ratio (HR) for death following interval cancer compared\nto CRC following positive result was 1.65 (1.32, 2.05) following the first screen and 1.71 (1.00, 2.91) following the second screen.\nConclusion. Interval CRCs following gFOBT screening comprise a significant proportion of CRC diagnosed within 2 years after\ngFOBT testing and are associated with a higher risk of death....
The epocs blood analysis system (Epocal Inc., Ottawa, Ontario,\nCanada) is a newly developed in vitro diagnostic hand-held analyzer\nfor testing whole blood samples at point-of-care, which\nprovides blood gas, electrolytes, ionized calcium, glucose, lactate,\nand hematocrit/calculated hemoglobin rapidly. The analytical\nperformance of the epocs system was evaluated in a tertiary\nhospital, see related research article ââ?¬Å?Analytical evaluation of the\nepocs point-of-care blood analysis system in cardiopulmonary\nbypass patientsââ?¬Â [1]. Data presented are the linearity analysis for\n9 parameters and the comparison study in 40 cardiopulmonary\nbypass patients on 3 epocs meters, Instrumentation Laboratory\nGEM4000, Abbott iSTAT, Nova CCX, and Roche Accu-Chek Inform II\nand Performa glucose meters....
Abstract\nBackground: Diabetes testing using saliva, rather than blood and urine, could facilitate diabetes screening in public\nspaces. We previously identified 1,5-anhydro-D-glucitol (1,5-AG) in saliva as a diabetes biomarker. The Glycomarkââ??¢\nassay kit is FDA approved for 1,5-AG measurement in blood. Here we evaluated its applicability for 1,5-AG quantification\nin saliva.\nMethods: Using pooled saliva samples, we validated Glycomarkââ??¢ assay use with a RX Daytona+ clinical chemistry\nanalyser. We then used this set-up to analyse 82 paired blood and saliva samples from a diabetes caseââ?¬â??control study,\nfor which broad mass spectrometry-based characterization of the blood and saliva metabolome was also available.\nOsmolality was measured to account for potential variability in saliva samples.\nResults: The technical variability of the read-outs for the pooled saliva samples (CV = 2.05 %) was comparable to that\nobtained with manufacturer-provided blood surrogate quality controls (CV = 1.38ââ?¬â??1.8 %). We found a high correlation\nbetween Glycomark assay and mass spectrometry measurements of serum 1,5-AG (r2 = 0.902), showing reproducibility\nof the non-targeted metabolomics results. The significant correlation between the osmolality measurements performed\nat two independent platforms with the time interval of 2 years (r2 = 0.887), also indicates the sample integrity.\nThe assay read-out for saliva was not correlated with the mass spectrometry-based 1,5-AG saliva measurements.\nComparison with the full saliva metabolome revealed a high correlation of the saliva assay read-outs with galactose.\nConclusions: Glycomarkââ??¢ assay read-outs for saliva were stable and replicable. However, the signal was dominated\nby galactose, which is biochemically similar to 1,5-AG and absent in blood. Adapting the 1,5-AG kit for saliva analysis\nwill require enzymatic depletion of galactose. This should be feasible, since the assay already includes a similar step for\nglucose depletion from blood samples....
Using high-performance liquid chromatography (HPLC) and 2,4-dinitrophenylhydrazine (2,4-DNPH) as a derivatizing reagent,\nan analytical method was developed for the quantitative determination of acetone in human blood.The determination was carried\nout at 365nm using an ultraviolet-visible (UV-Vis) diode array detector (DAD). For acetone as its 2,4-dinitrophenylhydrazone\nderivative, a good separation was achieved with a Thermo Acclaim C18 column (15 cm Ã?â?? 4.6mm Ã?â?? 3 ...
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