Evaluation of 99mTC-ECD SPECT/CT brain Imaging with NeuroGam analysis in Moyamoya disease after surgical revascularization.

To evaluate the clinical value of NeuroGam software in assessing the brain foci perfusion changes by TC-ECD single photon emission computed tomography/computed tomography (SPECT/CT) brain imaging in patients with Moyamoya Disease (MMD).Seventy-two patients with MMD who underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass combined with encephalo-duro-myo-synangiosis (EDMS) surgical revascularization were included. Baseline and follow-up TC-ECD SPECT/CT brain scans were performed on all patients at least twice before and after operation. Pre- and post-SPECT dicom images were reoriented into Talairach space using NeuroGam Software package. Additional visual analysis was performed. Differences mean pixel value between pre- and post- operation brain perfusion were assessed with paired t test and McNemar test.Significant differences in the number of hypoperfusion foci were found between visual assessment and NeuroGam aided assessment. More hypoperfusion foci were found by NeuroGam software aided assessment in the frontal, parietal, temporal, occipital lobe, thalamus, basal ganglia and cerebellum before and after surgery (P < .0001). According to NeuroGam software assessment, the perfusion of frontal, parietal, temporal lobe, anterior and middle cerebral regions on the operative side significantly improved before and after surgery (t = -3.734, t = -3.935, t = -5.099, t = -4.006, t = -5.170, all P < .001). However, no significant differences were found in the occipital lobe (t = -1.962, P = .054), thalamus (t = 1.362, P = .177), basal ganglia (t = -2.394, P = .019), and cerebellum (t = 1.383, P = .171) before and after surgery.The NeuroGam software provides a quantitative approach for monitoring surgical effect of MMD in a variable time (3-12 months after surgery). It could discover the perfusion changes that are neglected in conventional visual assessment.

Development of Dual Quantitative Lateral Flow Immunoassay for the Detection of Mycotoxins.

Lateral flow immunoassays have been widely used in recent years for detection of toxins, heavy metals, and biomarkers. To improve the efficiency of individual lateral flow immunoassays, multiplex analytical strips play an important role in the detection of several important analytes. In this chapter, development of a dual lateral flow immunoassay is presented for detection of a variety of low molecular weight molecules. Various buffers, additives, and materials are introduced and evaluated. Depending on the analyte to be tested, the technique allows for selection of optimum buffers, additives, and other materials.

Comparison of striatal dopamine transporter levels in chronic heroin-dependent and methamphetamine-dependent subjects.

To compare the effects of heroin and methamphetamine (METH) addiction on dopamine transporters (DATs) in the same dose and duration, we assessed DAT levels in the striatum by 99m Tc-TRODAT-1 single-photon emission computed tomography (SPECT) brain images in people with heroin and METH dependence. We recruited 21 healthy human controls, 23 heroin-dependent subjects and 25 METH abusers. The heroin- and METH-dependent subjects exhibited negative urine toxicology after undergoing physiological detoxification. All subjects underwent SPECT brain imaging, and specific tracer uptake ratios (SURs) were assessed bilaterally in the regions of interest. A significant SUR reduction in heroin-dependent subjects and METH-dependent subjects compared with healthy controls was found in the left striatum, right striatum, left caudate nucleus, right caudate nucleus, left putamen and right putamen. There were no significant differences in the heroin group and METH group for the left striatum, right striatum, left caudate nucleus, right caudate nucleus, left putamen and right putamen. The scores of craving, HAMA (Hamilton Anxiety Rating Scale), in heroin abusers were lower than in the METH abusers. Our results show that people with heroin and METH dependence who are currently abstinent had lower DAT levels in the striatum than healthy controls. There were no differences in striatal DAT in heroin and METH users. These results suggest that chronic heroin and METH abuse appears to produce similar effects in striatal DAT in humans. METH users may have more serious craving and anxiety symptoms than heroin users with prolonged abstinence.

A chimeric protein comprising the glucosyltransferase and cysteine proteinase domains of toxin B and the receptor binding domain of toxin A induces protective immunity against Clostridium difficile infection in mice and hamsters.

Clostridium difficile is the major cause of hospital-acquired infectious diarrhea and colitis in developed countries. The pathogenicity of C. difficile is mainly mediated by the release of 2 large potent exotoxins, toxin A (TcdA) and toxin B (TcdB), both of which require neutralization to prevent disease occurrence. We have generated a novel chimeric protein, designated mTcd138, comprised of the glucosyltransferase and cysteine proteinase domains of TcdB and the receptor binding domain of TcdA and expressed it in Bacillus megaterium. To ensure that mTcd138 is atoxic, 2 point mutations were introduced to the glucosyltransferase domain of TcdB, which essentially eliminates toxicity of mTcd138. Parenteral immunizations of mice and hamsters with mTcd138 induced protective antibodies to both toxins and provided protection against infection with the hyper-virulent C. difficile strain UK6.

Screening of single-stranded DNA (ssDNA) aptamers against a zearalenone monoclonal antibody and development of a ssDNA-based enzyme-linked oligonucleotide assay for determination of zearalenone in corn.

A hypotoxic immunosorbent assay for the detection of zearalenone (ZEN) was developed, by identifying a single-stranded DNA (ssDNA) aptamer with high specificity and affinity for a ZEN monoclonal antibody (mAb-ZEN). ssDNA aptamers, which could mimic ZEN epitopes, were identified using the modified systematic evolution of ligands by an exponential enrichment (SELEX) technique. The purified mAb-ZEN was coated on microtiter plates as a target recognized by the random oligonucleotide ssDNA library. The binding affinity between the aptamers and mAb-ZEN during each round was measured by the biotin­streptavidin­horseradish peroxidase system. During 15 rounds of screening, an increasing binding affinity was observed. The enriched ssDNA library binding to mAb-ZEN with high affinity was cloned, sequenced, and analyzed. One aptamer (number 46), which displays the highest affinity and specificity for the mAb-ZEN, was used to establish an indirect competition enzyme-linked oligonucleotide assay (ELONA) to measure the ZEN concentration in corn. Under optimal conditions, the regression equation for quantification of ZEN was y = −0.0778x + 0.713 (R2 = 0.9981). The detection limit and IC50 were 0.01 and 0.2 ng/mL, respectively, with a working range of 0.03­2.5 ng/mL. The recovery rates of the spiked samples in the ELONA ranged from 95 to 105%. Aptamers, which can mimic many types of low-weight analytes in agricultural products, could serve as surrogates for the development of hypotoxic, environmentally friendly immunological detection methods.

Single image defogging by multiscale depth fusion.

Restoration of fog images is important for the deweathering issue in computer vision. The problem is ill-posed and can be regularized within a Bayesian context using a probabilistic fusion model. This paper presents a multiscale depth fusion (MDF) method for defog from a single image. A linear model representing the stochastic residual of nonlinear filtering is first proposed. Multiscale filtering results are probabilistically blended into a fused depth map based on the model. The fusion is formulated as an energy minimization problem that incorporates spatial Markov dependence. An inhomogeneous Laplacian-Markov random field for the multiscale fusion regularized with smoothing and edge-preserving constraints is developed. A nonconvex potential, adaptive truncated Laplacian, is devised to account for spatially variant characteristics such as edge and depth discontinuity. Defog is solved by an alternate optimization algorithm searching for solutions of depth map by minimizing the nonconvex potential in the random field. The MDF method is experimentally verified by real-world fog images including cluttered-depth scene that is challenging for defogging at finer details. The fog-free images are restored with improving contrast and vivid colors but without over-saturation. Quantitative assessment of image quality is applied to compare various defog methods. Experimental results demonstrate that the accurate estimation of depth map by the proposed edge-preserved multiscale fusion should recover high-quality images with sharp details.

Simultaneous quantitative determination of multiple mycotoxins in cereal and feedstuff samples by a suspension array immunoassay.

Mycotoxins produced by different species of fungi may coexist in single cereal and feedstuff samples, which could become highly toxic for humans and animals. In order to quantify four mycotoxins (zearalenone, fumonisin B1, deoxynivalenol, and aflatoxin B1) in cereal and feedstuff samples simultaneously, a new suspension array immunoassay was developed. Antimycotoxin monoclonal antibodies were conjugated to the surface of different encoding microspheres (19#, 37#, 39#, and 49#), and mycotoxin-protein conjugates were then coupled with biotin. Using streptavidin-phycoerythrin as a signal reporter protein, this direct competition multiple suspension array immunoassay was optimized. The results showed that the detection limits for zearalenone, fumonisin B1, deoxynivalenol, and aflatoxin B1 were 0.51, 6.0, 4.3, and 0.56 ng/mL, respectively, with detection ranges of 0.73-6.8, 11.6-110.3, 8.6-108.1, and 1.1-14.1 ng/mL, respectively. For the detection of the spiked samples, the recovery rates were between 92.3% and 115.5%. This method also shows a good correlation coefficient (r = 0.99, P < 0.01) with liquid chromatography-tandem mass spectrometry in the detection of toxins in commercial cereal and feedstuff samples. This suspension array immunoassay was high-throughput and accurate for the rapid quantitative detection of multiple mycotoxins in commercial cereal and feedstuff samples.

Rapid simultaneous quantification of zearalenone and fumonisin B1 in corn and wheat by lateral flow dual immunoassay.

A lateral flow dual immunoassay (LFDIA) was developed for rapid quantitative detection of zearalenone (ZEN) and fumonisin B1 (FB1) in corn and wheat samples on a single test strip. Two test lines and the control line on the nitrocellulose membrane were coated with ZEN and FB1 conjugates and goat anti-mouse IgG, respectively. Colloidal gold nanoparticles were conjugated with monoclonal antibodies against ZEN or FB1. The intensity of the test lines was analyzed by a photometric strip reader to determine the concentrations of ZEN and FB1 based on the calibration curves of known concentrations versus intensity readings. Test parameters such as types of buffers, ratio of the two gold-labeled antibodies, and dilution of the sample extracts and the gold-labeled antibodies were optimized. The detection limit was 0.35 and 5.23 ng/mL for ZEN and FB1, respectively, and the corresponding detection ranges were 0.94-7.52 and 9.34-100.45 ng/mL, respectively. Spiked and natural samples were analyzed using both LFDIA and liquid chromatography-tandem mass spectrometry. The two methods had a good correlation (R(2) = 0.96). The dual quantitative LFDIA is sensitive, rapid, and easy-to-use for on-site testing of a large number of samples.

Novel chemiluminescence immunoassay for the determination of zearalenone in food samples using gold nanoparticles labeled with streptavidin-horseradish peroxidase.

A novel highly sensitive chemiluminescence immunoassay (CLIA) was developed to detect zearalenone in food samples by using both biotinylated zearalenone conjugates and gold (Au) nanoparticles labeled with streptavidin-horseradish peroxidase for signal amplification. Biotinylated zearalenone-ovalbumin conjugates and Au nanoparticles labeled with streptavidin-horseradish peroxidase were synthesized separately. The concentrations of immunoreagents and the reaction times of these immunoreagents were optimized to improve the performances of analytical methods. For the CLIA based on biotinylated zearalenone conjugates and Au nanoparticles labeled with streptavidin-horseradish peroxidase, the limit of detection was 0.008 ng/mL and the IC50 was 0.11 ng/mL. The linear working range was 0.02-0.51 ng/mL. The cross-reactivities with the zearalenone analogues (α-zearalanol, zearalanone, α-zearalenol, ß-zearalanol, and ß-zearalenol) were 32, 17, 12, 0.3, and 0.1%, respectively. The recovery rates in spiked food samples were 97-117%, and the intraday and interday relative standard deviations were both <10%. Parallel analysis of natural food samples showed a good correlation between this novel CLIA and liquid chromatography-tandem mass spectrometry. This method provides a rapid, accurate, and highly sensitive method to determine levels of zearalenone in food samples.