Zystein LLC

Fayetteville, AR, United States

Zystein LLC

Fayetteville, AR, United States
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Zhang Z.,Nanchang University | Wang L.,Nanchang University | Xu H.,Nanchang University | Aguilar Z.P.,Zystein LLC. | And 6 more authors.
Food Control | Year: 2014

Bacillus cereus is an etiological agent of food-borne disease that can cause a type of emesis. To develop a sensitive and reliable diagnosis technique for detecting all the species of the B.cereus group, specific primers were designed to target a recently discovered part of the cereulide synthetase gene (cesB) for emetic B.cereus and 16S rRNA for non-emetic B.cereus. To detect PCR signals only from viable cells, propidium monoazide (PMA) was selected to eliminate the false-positive results. In addition, an internal amplification control (IAC) was applied to meet diagnostic multiplex PCR requirements that will prevent the occurrence of false-negative results. The inclusivity and exclusivity of the mPCR assay were estimated using a panel of 100 strains, including 2 emetic B.cereus, 77 non-emetic B.cereus and 21 non-Bacillus strains. The limit of detection (LOD) for dead B.cereus without PMA treatment in pure bacteria culture was 4.0×102CFU/mL, as low as 7.5×100CFU/mL for viable B.cereus without PMA treatment, and 7.5×101CFU/mL for viable B.cereus with PMA treatment. B.cereus in spiked food produce was detected specifically and sensitively at 1.0×103CFU/g which was the lowest concentration detected. This novel PMA-mPCR-IAC assay is rapid and reliable, providing an efficient diagnostic tool with promising application in monitoring food samples. © 2013 Elsevier Ltd.

Wang L.,Nanchang University | Li P.,Nanchang University | Zhang Z.,Nanchang University | Chen Q.,Nanchang University | And 7 more authors.
Food Control | Year: 2014

To improve the accuracy of current methods for the detection of Escherichia coli O157:H7 foodborne disease outbreaks, two reagents, propidium monoazide (PMA) and sodium deoxycholate (SD), were utilized to eliminate the interference of dead and injured cells for qPCR that was combined with immunomagnetic separation (IMS) for cell enrichment in an IMS-SD-PMA-qPCR assay. The optimal SD concentration and the optimal incubation time with SD were recorded at 0.1% and 20min, respectively. The number of bacteria survivors was compared using plate counts, qPCR, PMA-qPCR, and SD-PMA-qPCR assays after the cell suspensions were heat treated at 63°C or freeze stored at-20°C. Cell suspensions treated or not treated with PMA and treated with SD resulted in significantly lower number of bacteria survivors than those analyzed without SD treatment which indicated that dead cell DNA was eliminated with SD. More importantly, the number of bacteria survivors from those analyzed with SD-PMA-qPCR showed a direct correlation with those analyzed using the plate counts methods. In addition, in order to improve the limit of detection (LOD) and shorten the detection time, immunomagnetic separation (IMS) was adopted to capture and enrich the target bacteria. Using spiked milk as a matrix, the IMS-SD-PMA-qPCR showed a detection limit of 102CFU/mL. Significantly, even in the presence of 106CFU/mL of non-target bacteria, the LOD for the SD-PMA-qPCR with IMS separation for E.coli O157:H7 in spiked milk matrix was recorded at 102CFU/mL. This combination assay holds promise for the detection of foodborne E.coli O157:H7. © 2013 Elsevier Ltd.

Sharma H.S.,Uppsala University Hospital | Menon P.K.,Uppsala University Hospital | Lafuente J.V.,University of the Basque Country | Aguilar Z.P.,Zystein LLC | And 5 more authors.
Journal of Nanoscience and Nanotechnology | Year: 2014

Functionalized Magnetic Iron Oxide Nanoparticles (FMIONPs) are being explored for the development of various biomedical applications, e.g., cancer chemotherapy and/or several other radiological or diagnostic purposes. However, the effects of these NPs per se on the central nervous system (CNS) injury or repair are not well known. This review deals with different aspects of FMIONPs in relation to brain function based on the current literature as well as our own investigation in animal models of CNS injuries. It appears that FMIONPs are innocuous when administered intravenously within the CNS under normal conditions. However, abnormal reactions to FMIONPs in the brain or spinal cord could be seen if they are combined with CNS injuries e.g., hyperthermia or traumatic insults to the brain or spinal cord. Thus, administration of FMIONPs in vivo following whole body hyperthermia (WBH) or a focal spinal cord injury (SCI) exacerbates cellular damage. Since FMIONPs could help in diagnostic purposes or enhance the biological effects of radiotherapy/chemotherapy it is likely that these NPs may have some adverse reaction as well under disease condition. Thus, under such situation, adjuvant therapy e.g., Cerebrolysin (Ever NeuroPharma, Austria), a suitable combination of several neurotrophic factors and active peptide fragments are the need of the hour to contain such cellular damages caused by the FMIONPs in vivo. Our observations show that co-administration of Cerebrolysin prevents the FMIONPs induced pathologies associated with CNS injuries. These observations support the idea that FMIONPs are safe for the CNS in disease conditions when co-administered with cerebrolysin. This indicates that cerebrolysin could be used as an adjunct therapy to prevent cellular damages in disease conditions where the use of FMIONPs is required for better efficacy e.g., cancer treatment. Copyright © 2014 American Scientific Publishers All rights reserved.

Al-Ogaidi I.,University of Baghdad | Al-Ogaidi I.,West Virginia University | Gou H.,West Virginia University | Aguilar Z.P.,Zystein LLC | And 5 more authors.
Chemical Communications | Year: 2014

An immunoassay has been developed for the detection of the ovarian cancer biomarker CA-125 by utilizing the chemiluminescence resonance energy transfer to graphene quantum dots. This biosensor shows a wide linear range from 0.1 U mL-1 to 600 U mL-1 with a limit of detection of 0.05 U mL-1 for CA-125 in a buffer solution. © The Royal Society of Chemistry.

Huang X.,Nanchang University | Aguilar Z.P.,Zystein LLC | Li H.,Nanchang University | Lai W.,Nanchang University | And 3 more authors.
Analytical Chemistry | Year: 2013

A Ru(phen)3 2+-doped silica fluorescent nanoparticle (FN)-based immunochromatographic test strip (ICTS) sensor was developed for rapid, high sensitivity, easy to use, and low cost quantitative detection of enrofloxacin (ENR) residues in chicken meat. The fluorescence signal intensity of the FNs at the test line (FIT) and control line (FIC) was determined with a prototype of a portable fluorescent strip reader. Unique properties of Ru(phen)3 2+ doped silica nanoparticles (e.g., large Stokes shift, high emission quantum yield, and long fluorescence lifetime) were combined with the advantages of ICTS and an easy to make portable fluorescent strip reader. The signal was based on FIT/FIC ratio to effectively eliminate strip to strip variation and matrix effects. Various parameters that influenced the strip were investigated and optimized. Quantitative ENR detection with the FNs ICTS sensor using 80 μL sample took only 20 min, which is faster than the commercial ELISA kit (that took 90 min). The linear range of detection in chicken extract was established at 0.025-3.500 ng/mL with a half maximal inhibitory concentration at 0.22 ± 0.02 ng/mL. Using the optimized parameters, the limit of detection (LOD) for ENR using the FNs ICTS sensor was recorded at 0.02 ng/mL in chicken extract. This corresponds to 0.12 μg/kg chicken meat which is two (2) orders of magnitude better that the maximum residue limits (MRLs) imposed in Japan (10 μg/kg) and three (3) orders of magnitude better than those imposed in China. The intra- and inter-assay coefficient of variations (CVs) were 6.04% and 12.96% at 0.5 ng/mL, 6.92% and 12.61% at 1.0 ng/mL, and 6.66% and 11.88% at 2.0 ng/mL in chicken extract, respectively. The recoveries using the new FNs ICTS sensor from fifty (50) ENR-spiked chicken samples showed a highly significant correlation (R 2 = 0.9693) with the commercial enzyme-linked immunosorbent assay (ELISA) kit. The new FNs ICTS sensor is a simple, rapid, sensitive, accurate, and inexpensive quantitative detection of ENR residues in chicken meat and extracts. © 2013 American Chemical Society.

Yang L.,Nanchang University | Kuang H.,Nanchang University | Zhang W.,Nanchang University | Aguilar Z.P.,Zystein LLC. | And 4 more authors.
Nanoscale | Year: 2015

In spite of the immense benefits from iron oxide magnetic nanoparticles (IOMNs), there is scanty information regarding their metabolic activities and toxicity in vivo. In this study, we investigated the size dependent in vivo biodistribution, toxicokinetics, and toxicity and gene expression changes of various sizes of carboxyl coated IOMNs (diameters of 10, 20, 30, and 40 nm). Our findings demonstrated that the various sizes of IOMNs accumulated primarily in the liver and spleen on the first day post-injection. Interestingly, size dependent biodistribution and transport were observed: the smallest IOMNs (10 nm) showed the highest uptake by the liver, whereas the largest IOMNs (40 nm) showed the highest uptake by the spleen. Moreover, the IOMNs with the smallest size (10 nm) were cleared faster from the liver and kidneys, but more readily entered the brain and the uterus. IOMNs with the largest size (40 nm) accumulated more readily but were easily eliminated in the spleen. However, the level of iron in the heart decreased in all IOMN exposed groups. In addition, blood biochemistry, hematological analyses and histological examination demonstrated that there was no apparent acute toxicity caused by IOMNs in mice. However, smaller IOMNs (10 nm and 20 nm) more effectively changed the expression level of sensitive genes related to oxidant stress, iron transport, metabolic process, apoptosis, and others. This journal is © The Royal Society of Chemistry.

Al-Ogaidi I.,University of Baghdad | Al-Ogaidi I.,West Virginia University | Gou H.,West Virginia University | Al-kazaz A.K.A.,University of Baghdad | And 4 more authors.
Analytica Chimica Acta | Year: 2014

The gold nanostar@silica core-shell nanoparticles conjugated with glucose oxidase (GOx) enzyme molecules have been developed as the surface-enhanced Raman scattering (SERS) biosensor for label-free detection of glucose. The surface-immobilized GOx enzyme catalyzes the oxidation of glucose, producing hydrogen peroxide. Under laser excitation, the produced H2O2 molecules near the Au nanostar@silica nanoparticles generate a strong SERS signal, which is used to measure the glucose concentration. The SERS signal of nanostar@silica~GOx nanoparticle-based sensing assay shows the dynamic response to the glucose concentration range from 25μM to 25mM in the aqueous solution with the limit of detection of 16μM. The sensing assay does not show any interference when glucose co-exists with both ascorbic acid and uric acid. The sensor can be applied to a saliva sample. © 2013 Elsevier B.V.

PubMed | Nanchang University, Zystein LLC and University of Science and Technology of China
Type: | Journal: Environmental pollution (Barking, Essex : 1987) | Year: 2016

Ultra-fine-ZnO showed low toxicity in complex water matrix containing multiple components such as PBS buffer and the toxic mechanism of ultra-fine-ZnO has not been clearly elucidated. In present study, enhanced antibacterial activity of 200nm diameter ultra-fine-ZnO in PBS buffer against Bacillus cereus and Escherichia coli were observed in the presence of several organic acids in comparison with ultra-fine-ZnO in PBS buffer alone. These findings indicated that the toxic effects of the ultra-fine-ZnO was dependent on the concentration of released Zn

PubMed | Nanchang University and Zystein LLC.
Type: | Journal: Journal of hazardous materials | Year: 2016

ZnO nanoparticles (NPs) have been assessed to show adverse effects on the liver, but the molecular mechanisms and the role of nanoparticle properties in these adverse reactions have not been sufficiently studied. In this study, the toxicity of various sizes of ZnO particles (bulk, 90nm, and 30nm) that were ingested orally over a period of 3days were evaluated in mice. The blood biochemistry, hematological analyses, and histopathological evaluation showed that there was apparent toxicity caused by smaller ZnO NPs (30nm) in liver. The smallest ZnO NPs showed highest accumulation in the mice liver. The RT-qPCR data indicated that 30nm ZnO NPs can induce significant endoplasmic reticulum (ER) stress responses. The ER stress marker of PERK, eIF2, ATF4, Chop, JNK, caspase-12, caspase-9, GRP94, and Bax at the mRNA levels were higher expression in 30nm ZnO NP than that in bulk or 90nm ZnO. These findings implied that the smaller ZnO NPs (30nm) activated ER stress responses that signified severe apoptosis in murine liver.

PubMed | Nanchang University, Zystein LLC and University of Hong Kong
Type: Journal Article | Journal: Applied microbiology and biotechnology | Year: 2016

In this study, we investigated the antibacterial activity of ZnO nanoparticles (NPs) and Lactobacillus-fermentation liquor (LFL) against two pathogenic bacteria in vitro and in vivo. Bactericidal tests were performed on solid agar plates and quantitative real-time PCR (qPCR), and denaturing gradient gel electrophoresis (DGGE) techniques were used to examine the antibacterial activity of the mixture of ZnO NPs and LFL in vivo. The results showed that the mixture exhibited higher antibacterial activity against Salmonella typhimurium in vitro in comparison with ZnO NPs alone. The results showed that ZnO NPs and LFL significantly enhanced microbial diversity in mouse intestine which suggested a synergistic antibacterial activity against the tested pathogenic bacteria that could be used for the control of the spread and persistence of bacterial infections.

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