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3.
J Appl Microbiol ; 131(6): 2957-2970, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34060684

ABSTRACT

AIMS: Wuyiencin is a nucleoside antibiotic produced by Streptomyces albulus CK-15. The aim of this study was to determine whether wuyiencin can be used, as a suitable alternative to chemical pesticides, to protect cucumbers (Cucumis sativus L.) from powdery mildew caused by Sphaerotheca fuliginea. Further, the mechanisms underlying the control of cucumber powdery mildew by S. albulus CK-15 were preliminarily elucidated. METHODS AND RESULTS: Wuyiencin solutions of different concentrations were used to treat infected cucumber plants under greenhouse conditions. The results indicated that wuyiencin could significantly reduce powdery mildew disease incidence, with a maximum prevention efficacy of 94·38%. Further, scanning electron micrographs and enzyme assays showed that wuyiencin inhibited S. fuliginea spore growth and elicited the activity of plant systemic resistance-related enzymes. Additionally, real-time quantitative reverse transcription PCR suggested that wuyiencin can activate a salicylic acid-dependent plant defence response. CONCLUSIONS: Wuyiencin produced by S. albulus CK-15 possessed antifungal effects and was able to mitigate cucumber powdery mildew disease via antagonistic action. Wuyiencin also induced defence responses in the plants. SIGNIFICANCE AND IMPACT OF THE STUDY: These results reinforce the biotechnological potential of wuyiencin as both an antagonistic agent and an inducer of plant systemic resistance.


Subject(s)
Ascomycota , Cucumis sativus , Plant Diseases , Streptomyces
4.
J Prev Alzheimers Dis ; 8(3): 249-256, 2021.
Article in English | MEDLINE | ID: mdl-34101780

ABSTRACT

OBJECTIVES: To evaluate the combined action of folic acid and vitamin B12 supplementation on cognitive performance and inflammation in patients with Alzheimer's disease (AD). DESIGN: This was a randomized, single-blind, placebo-controlled trial. PARTICIPANTS: Patients (n=120) diagnosed clinically as probable AD and in stable condition from Tianjin Key Laboratory of Cerebrovascular and Neurodegenerative Diseases. MEASUREMENTS: Individuals were randomly divided into the intervention group (n=60, folic acid 1.2 mg/d + vitamin B12 50 µg/d) and the placebo group (n=60). Cognitive performance, blood folate, vitamin B12, one carbon cycle metabolite, and inflammatory cytokine levels were measured at baseline and after 6 months. The data were analyzed using linear mixed models for repeated measures. RESULTS: A total of 101 participants (51 in the intervention group and 50 in the placebo group) completed the trial. Folic acid plus vitamin B12 supplementation had a beneficial effect on the MoCA total scores (P=0.029), naming scores (P=0.013), orientation scores (P=0.004), and ADAS-Cog domain score of attention (P=0.008), as compared to those of the control subjects. Moreover, supplementation significantly increased plasma SAM (P<0.001) and SAM/SAH (P<0.001), and significantly decreased the levels of serum Hcy (P<0.001), plasma SAH (P<0.001), and serum TNFα (P<0.001) compared to in the control subjects. CONCLUSIONS: Folic acid and vitamin B12 supplementation showed a positive therapeutic effect in AD patients who were not on a folic acid-fortified diet. The findings of this study help to delineate nutrient intervention as far as public health management for the prevention of dementia is concerned.


Subject(s)
Alzheimer Disease/drug therapy , Cognitive Dysfunction/drug therapy , Folic Acid/therapeutic use , Inflammation/drug therapy , Vitamin B 12/therapeutic use , Aged , Alzheimer Disease/blood , China , Cytokines , Dietary Supplements , Female , Humans , Male , Neuropsychological Tests/statistics & numerical data , Single-Blind Method
5.
Eur Rev Med Pharmacol Sci ; 24(18): 9265-9273, 2020 09.
Article in English | MEDLINE | ID: mdl-33015767

ABSTRACT

OBJECTIVE: The aim of this study was to investigate whether microRNA-150-5p was involved in osteosarcoma cell proliferation and invasiveness via modulating vascular endothelial growth factor A (VEGFA) expression. PATIENTS AND METHODS: 10 pairs of osteosarcoma tissues and para-cancerous tissues were collected from patients with osteosarcoma in our center from February 2012 to July 2018. Relative expression levels of microRNA-150-5p and VEGFA in tissues and cell lines were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Luciferase reporter gene assay was conducted to illustrate the binding interplay between microRNA-150-5p and VEGFA. Furthermore, proliferative and invasive potentials in HOS and MG-63 cells regulated by both microRNA-150-5p and VEGFA were determined using Cell Counting Kit-8 (CCK-8), colony formation assay, and transwell assay, respectively. RESULTS: MicroRNA-150-5p was remarkably downregulated, while VEGFA was upregulated in osteosarcoma tissues compared with para-cancerous tissues (p<0.05). Similar results were observed in osteosarcoma cells and normal osteoblasts. Overexpression of microRNA-150-5p significantly inhibited the proliferation and invasion of osteosarcoma cells (p<0.05). Luciferase reporter gene assay demonstrated that microRNA-150-5p could target to VEGFA to negatively modulate its expression. In addition, the knockdown of VEGFA remarkably weakened osteosarcoma cell proliferative and invasive capacities (p<0.05). CONCLUSIONS: MicroRNA-150-5p weakens proliferative and invasive potentials in osteosarcoma cells by downregulating VEGFA level. All our findings suggest that microRNA-150-5p/VEGFA axis is a promising target for osteosarcoma treatment.


Subject(s)
Bone Neoplasms/metabolism , Down-Regulation , MicroRNAs/metabolism , Osteosarcoma/metabolism , Vascular Endothelial Growth Factor A/metabolism , Bone Neoplasms/pathology , Cell Proliferation , Cells, Cultured , Humans , MicroRNAs/genetics , Osteosarcoma/pathology , Vascular Endothelial Growth Factor A/genetics
6.
J Appl Microbiol ; 129(3): 565-574, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32145135

ABSTRACT

AIM: The aim of the present work was to investigate the overexpression of the wysR gene in Streptomyces albulus var. wuyiensis strain CK-15 based on the ΔwysR3 mutant strain including the effect on morphological development, wuyiencin production and antibacterial activity. At the same time, we report a new rapid method for producing genetically engineered strains for industrial production of wuyiencin. METHODS AND RESULTS: We developed a method to create a wysR overexpression strain based on the ΔwysR3 mutant strain by direct transformation. In this method, the desired gene fragment to be overexpressed was amplified by polymerase chain reaction (PCR) using Phusion High Fidelity DNA polymerase and fused with the linearized pSETC integrative plasmid by Gibson assembly. The resulting recombinant plasmid was transformed into ΔwysR3 mutant strain by the intergeneric conjugation method. The plasmid was then integrated into the chromosome and the resulting apramycin-resistant overexpression strain was confirmed by PCR using the Apra-F and Apra-R primers. Finally, we successfully screened the genetically engineered strain with overexpression of wysR gene in ΔwysR3 mutant. CONCLUSION: We can conclude that overexpression of wysR gene in ΔwysR3 mutant strain proved to be an effective strategy for significantly increasing wuyiencin production together with faster morphological development. Quantitative real-time RT-PCR analysis showed that wysR regulated wuyiencin biosynthesis by modulating other putative regulatory genes and bld, whi, chp, rdl and ram family genes are crucial for the morphological development. SIGNIFICANCE AND IMPACT OF THE STUDY: Overexpression of wysR gene in the ΔwysR3 mutant strain named OoWysR strain may increase the efficiency in the industrial fermentation processes for wuyiencin production. The mechanism by which wysR overexpression promotes rapid sporulation and a high yield of wuyiencin production is likely related to modulation of other putative regulatory genes.


Subject(s)
Anti-Bacterial Agents/metabolism , Bacterial Proteins/metabolism , Genes, Bacterial , Streptomyces/metabolism , Bacterial Proteins/genetics , Cloning, Molecular , Fermentation , Gene Expression , Gene Expression Regulation, Bacterial , Mutation , Plasmids , Streptomyces/genetics
7.
Eur Rev Med Pharmacol Sci ; 22(23): 8151-8160, 2018 12.
Article in English | MEDLINE | ID: mdl-30556853

ABSTRACT

OBJECTIVE: Bladder cancer is the most prevalent genitourinary malignant disorder worldwide. We aimed to observe effects of high-glucose on bladder cancer proliferation and explore the associated mechanisms. MATERIALS AND METHODS: Human bladder cancer cell line, T24, was divided into Blank, Control (Ctrl), 10 mmol/l, 20 mmol/l and 30 mmol/l group. T24 cell proliferation was evaluated by using multiple table tournament (MTT) assay and colony formation analysis, respectively. Quantitative Real-time PCR (qRT-PCR) assay was employed to examine mRNA expression of Wnt-5a and ß-catenin. Meanwhile, Western blot assay was used to evaluate expression of Wnt-5a and ß-catenin protein. The linear regression analysis was utilized to analyze correlation between Wnt-5a/ß-catenin expression and T24 cell proliferation. RESULTS: High-glucose significantly enhanced proliferation of T24 cells compared to that of Blank and Ctrl group (p < 0.05). High-glucose significantly promoted colony formation of T24 cells compared to that of Blank and Ctrl group (p < 0.05). High-glucose significantly up-regulated Wnt-5a mRNA and protein expression compared to that of Blank and Ctrl group (p < 0.01). High-glucose significantly increased ß-catenin mRNA and protein expression compared to that of Blank and Ctrl group (p < 0.01). Effects of high-glucose on T24 cell proliferation were increased following with the enhanced glucose concentration. Wnt/ß-catenin signaling pathway molecules were correlated with colony formation of T24 cells (p < 0.05). CONCLUSIONS: High-glucose promoted the proliferation of T24 cells by activating the Wnt/ß-catenin signaling pathway. This study would provide the novel targets for bladder cancer therapy.


Subject(s)
Cell Proliferation/drug effects , Glucose/toxicity , Urinary Bladder Neoplasms/metabolism , Wnt Signaling Pathway/drug effects , Wnt-5a Protein/metabolism , beta Catenin/metabolism , Cell Line, Tumor , Cell Movement/drug effects , Gene Expression Regulation, Neoplastic , Humans , Neoplasm Metastasis , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/pathology , Wnt Signaling Pathway/genetics , Wnt-5a Protein/genetics , beta Catenin/genetics
8.
Cell Mol Biol (Noisy-le-grand) ; 63(10): 49-53, 2017 Oct 26.
Article in English | MEDLINE | ID: mdl-29096743

ABSTRACT

Oxidative stress plays a critical task in the biochemical and pathological alteration linked with myocardial ischemic-reperfusion injury (IRI). This warrants identifying agents with a potential for preventing such damage in an effective way. A novel plant based product, Pycnogenol, obtained from the French maritime pine (Pinus pinaster ssp. atlantica) bark extract was known for its tremendous antioxidant potential (both in vivo, in vitro). It was able to attenuate the symptoms of immune dysfunction through restoring a cellular antioxidant status in low micronutrient-induced immune deficient mice. Consequently, the present study was deals with the determination of protective effect of Pycnogenol in ischemic-reperfusion injury (IRI) in rats via Non-recirculating Langendorff's technique. The effect of Pycnogenol  on the level of various key biomarkers in the rat heart homogenate was determined, such as, myocardial thiobarbituric acid reactive substances (TBARS, a marker of lipid peroxidation), lactic dehydrogenase (LDH) (a marker of tissue injury) and effect on endogenous antioxidants, e.g., superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx). The activity of these biomarkers appreciably improved in Pycnogenol-treated group than IRI group (P < 0.05). The effect of Pycnogenol was further confirmed via histopathological examination of cardiac tissues, which suggests that, it considerably improved the injury related to tissue damage through suppression of edema and infiltration of neutrophil compared to IRI group. It also showed modulation of the expression of apoptotic factors, e.g. Bcl-2, bax and caspase-9 as confirmed by western blot analysis.


Subject(s)
Cardiotonic Agents/pharmacology , Flavonoids/pharmacology , Myocardial Reperfusion Injury/drug therapy , Plant Extracts/pharmacology , Animals , Biomarkers, Pharmacological/analysis , Cardiotonic Agents/therapeutic use , Edema, Cardiac/drug therapy , Edema, Cardiac/metabolism , Flavonoids/therapeutic use , Isolated Heart Preparation , Male , Neutrophil Infiltration/drug effects , Oxidative Stress/drug effects , Plant Extracts/therapeutic use , Rats , Rats, Wistar
9.
Ultramicroscopy ; 166: 1-8, 2016 07.
Article in English | MEDLINE | ID: mdl-27093687

ABSTRACT

STEM image simulation is achieved via hybrid CPU/GPU programming under parallel algorithm architecture to speed up calculation on a personal computer (PC). To utilize the calculation power of a PC fully, the simulation is performed using the GPU core and multi-CPU cores at the same time to significantly improve efficiency. GaSb and an artificial GaSb/InAs interface with atom diffusion have been used to verify the computation.

10.
Fa Yi Xue Za Zhi ; 32(3): 180-183, 2016 Jun.
Article in English | MEDLINE | ID: mdl-29171735

ABSTRACT

OBJECTIVES: To establish a novel multiplex amplification system which comprises 24 Y-STR loci. METHODS: otal 24 Y-STR gene loci, concluding DYS531, DYS630, DYS622, DYS552, DYS510, DYS449, DYS459a/b, DYS446, DYS443, DYS635, DYS587, DYS527a/b, DYS460, Y-GATA-A10, DYS520, DYS557, DYS522, DYS481, DYS570, DYS385a/b, DYS444, were chosen for establishing the fluorescence multiplex amplification system. The specificity, identity, sensitivity, balance of the amplification, anti-interference and accuracy of the system were detected and the gene diversity was investigated in the population of Guangdong. RESULTS: No band was found in nonhuman and female samples that were tested by the established multiplex amplification system. The same genotyping results were obtained from different tissues of the same person. Complete profiles could be obtained from more than 0.1 ng of the standard sample 9948. The loss of alleles was found when the common inhibitors such as hemoglobin and calcium ion were added 120-200 µmol/L and 1.5-2.0 mmol/L respectively to the system which with a strong anti-interference to the indigo, humic acid and EDTA. The typing of 24 Y-STR system could give the reliable results when 146 unrelated male individuals were detected and compared with the Yfiler system parallelly. The haplotype diversity (HD) of the population in Guangdong reached 0.999 72 that was better than the result retained from Yfiler system, which the HD was 0.998 58. CONCLUSIONS: The fluorescence amplification system with 24 Y-STR loci established in present study has a wildly application prospect and can be used for cases inspection, paternity tests and Y-STR database construction.


Subject(s)
Asian People/genetics , Chromosomes, Human, Y/genetics , Genetics, Population , Alleles , China , Female , Fluorescence , Genotype , Haplotypes/genetics , Humans , Male , Multiplex Polymerase Chain Reaction , Polymerase Chain Reaction , Polymorphism, Genetic , Software
11.
Oncol Lett ; 10(4): 2422-2426, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26622863

ABSTRACT

The aim of this study was to observe the inhibitory and therapeutic effects of small interfering RNA (siRNA) targeting Livin in EJ human bladder cancer cells. Specific siRNA targeting Livin was synthesized and transfected into EJ human bladder cancer cells treated or not treated with mitomycin-C (MMC). Livin mRNA and protein, as well as proliferation and apoptosis of EJ cells was examined with reverse transcription-polymerase chain reaction, western blotting, Cell Counting Kit-8 assay and flow cytometry, respectively. The results indicated that the expression of Livin mRNA and protein in EJ cells was significantly decreased by siRNA Livin. The proliferation of EJ cells was significantly inhibited by treatment with MMC and transfection of siRNA Livin. The inhibition of cell proliferation by treatment with MMC was further enhanced by transfection of siRNA Livin. The apoptotic rate of cells transfected with siRNA Livin and treated with MMC was significantly higher than those cells receiving a single transfection of siRNA Livin and single treatment of MMC. In conclusion, the present study demonstrates that transfection of siRNA Livin induces growth suppression and apoptosis in EJ human bladder cancer cells, and increases the chemotherapeutic sensitivity of cells to MMC.

12.
Lett Appl Microbiol ; 61(6): 596-602, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26400053

ABSTRACT

UNLABELLED: We developed a real-time PCR assay to specifically detect and quantify the efficacy of a biological fungicide from Streptomyces ahygroscopicus var. wuyiensis on tomato leaves. This fungicide, the natural secondary metabolite wuyiencin, is an antifungal agent against Botrytis cinerea. Specific primers were designed based on the ß-actin gene sequences, which were used to detect a 303 bp fragment from B. cinerea isolates. Our assay is highly sensitive and can be used to reliably detect and quantify as little as 1·75 pg of B. cinerea DNA. We used this detection method to monitor the progression of B. cinerea infection in inoculated plant material under preventive (wuyiencin) and nonpreventive treatment. After 5 days, plants under preventive treatment exhibited a sharp decrease in fungal biomass and no symptoms, whereas plants under nonpreventive treatment displayed severe disease symptoms. The results demonstrate that wuyiencin has significant effects on B. cinerea in tomato plants and that real-time PCR is a reliable method for evaluating the effects of Streptomyces wuyiensis CK-15 on B. cinerea. SIGNIFICANCE AND IMPACT OF THE STUDY: Botrytis cinerea commonly produces latent or nonsymptomatic infection on and within plant tissues, which can develop into symptomatic infection when triggered by changes in environmental conditions or host plant physiology. In this study, we develop a specific, sensitive real-time PCR assay for detecting and quantifying B. cinerea on tomato leaves to determine the control efficacy of Streptomyces ahygroscopicus var. wuyiensis as a biological fungicide. Our findings demonstrate that wuyiencin has significant effects on B. cinerea in tomato plants and that real-time PCR is a reliable method for evaluating the effects of biological fungicides on plant pathogens.


Subject(s)
Antifungal Agents/pharmacology , Botrytis/drug effects , Fungicides, Industrial/pharmacology , Plant Diseases/prevention & control , Solanum lycopersicum/microbiology , Streptomyces/metabolism , Antifungal Agents/metabolism , Botrytis/growth & development , DNA Primers , Plant Diseases/microbiology , Plant Leaves/microbiology , Real-Time Polymerase Chain Reaction/methods , Streptomyces/genetics
13.
Cell Prolif ; 47(6): 527-39, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25355404

ABSTRACT

OBJECTIVES: Icariin, a prenylated flavonol glycoside isolated from traditional Chinese medicinal herb of the genus Epimedium, has been demonstrated to be a potential alternative therapy for osteoporosis, and its action mechanism so far has been mainly attributed to its phytoestrogenic property. As blood supply to bone is considerably reduced with ageing and by the menopause, we hypothesized that icariin treatment would reduce bone loss by preventing ischaemia-induced hypoxic damages to bone. MATERIALS AND METHODS: To investigate effects of icariin treatment on cultured rat calvarial osteoblasts exposed to hypoxic conditions (2% oxygen). RESULTS: Compared to normoxic control, cell viability decreased with time to 50% by 48 h in the hypoxic group, and icariin attenuated the reduction, dose dependently, with 10(-6) and 10(-5)  m concentrations showing significant protective effects. Icariin also inhibited increase of lactate dehydrogenase activity in culture media. Measurements on oxidative stress, cell cycling and cell survival indicated that icariin protected osteoblasts by reducing production of reactive oxygen species and malondialdehyde, increasing superoxide dismutase activity, arresting the cell cycle and inhibiting apoptosis. Icariin also preserved osteogenic differentiation potential of the hypoxic cells in a dose-dependent manner, compared to the hypoxia alone group, as revealed by increased levels of RUNX-2, OSX and BMP-2 gene expression, alkaline phosphatase activity, and formation of mineralized nodules. CONCLUSIONS: Our results demonstrated that icariin attenuated oxidative stress and apoptosis and preserved viability and osteogenic potential of osteoblasts exposed to hypoxia in vitro, and suggested that its anti-osteoporotic effect may be attributed to its anti-hypoxic activity and phytoestrogenic properties.


Subject(s)
Apoptosis/drug effects , Cell Hypoxia , Flavonoids/pharmacology , Osteoblasts/drug effects , Oxidative Stress/drug effects , Animals , Cell Cycle Checkpoints/drug effects , Cell Differentiation/drug effects , Cells, Cultured , Drugs, Chinese Herbal/pharmacology , Epimedium/chemistry , Epimedium/metabolism , Malondialdehyde/metabolism , Osteoblasts/cytology , Osteoblasts/enzymology , Osteogenesis/drug effects , Proliferating Cell Nuclear Antigen/metabolism , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Skull/cytology , Superoxide Dismutase/metabolism
14.
Environ Pollut ; 187: 10-21, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24418974

ABSTRACT

The traditional way to study Sources-Receptor Relationships (SRRs) of wet deposition is based on sensitivity simulation, which has weakness in dealing with the non-linear secondary formation pollutants (e.g. ozone and nitrate). An on-line source tracking method has been developed in the Nested Air Quality Prediction Modeling System (NAQPMS) coupled with cloud-process module for the first time. The new model can not only quantify the total volume of the sulfate, nitrate and ammonium wet deposition with more accuracy, but also trace these acidic species to their emitted precursors. Compared with previous studies, our result clearly shows: (1) East China and Central China, which are the two primary export regions, have 15-30% and 10% effect on wet deposition in other areas, respectively; (2) Besides the above two regions, the total acid deposition in Southwestern and Northeastern China have reached or exceeded the critical loads under their own environmental conditions.


Subject(s)
Air Pollutants/analysis , Environmental Monitoring/methods , Atmosphere/chemistry , China , Hydrogen-Ion Concentration , Models, Chemical , Nitrates/analysis , Ozone/analysis , Weather
15.
J Appl Microbiol ; 116(1): 81-8, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24016159

ABSTRACT

AIMS: Loop-mediated isothermal amplification (LAMP) assays have been developed recently for Salmonella detection. This study aimed at evaluating the robustness of two Salmonella LAMP assays in comparison with PCR and real-time quantitative PCR for food applications. METHODS AND RESULTS: Performance of the assays was examined under abusive preparation conditions, running temperatures and pH, and with the addition of various inhibitors and food rinses. LAMP achieved robust detection under abusive assay preparation conditions (holding at 22 and 37°C for up to 30 min) and running temperatures (57-68°C). With a hot-start DNA polymerase, PCR obtained comparable results under these temperature ranges. However, PCR performed markedly poorer under abusive pH. LAMP also showed greater tolerance to potential inhibitors than PCR. When food rinses including meat juice, chicken rinse, egg homogenate and produce homogenate were added at 20% of the reaction mix, PCR amplifications were completely inhibited, but LAMP reactions were not. CONCLUSIONS: Our results demonstrated that LAMP is a robust alternative to PCR in Salmonella detection for food applications. SIGNIFICANCE AND IMPACT OF THE STUDY: This study filled important knowledge gaps regarding the robustness of Salmonella LAMP assays. The findings will help bring Salmonella LAMP assays closer to wider applications in food testing.


Subject(s)
Food Microbiology , Salmonella , Animals , Meat , Nucleic Acid Amplification Techniques , Polymerase Chain Reaction , Real-Time Polymerase Chain Reaction , Salmonella/genetics , Sensitivity and Specificity
16.
Prev Vet Med ; 111(3-4): 286-96, 2013 Sep 01.
Article in English | MEDLINE | ID: mdl-23777649

ABSTRACT

In this paper we analyze the impact of the sensitivity and specificity of a Mycobacterium avium (Ma) test on pig producer incentives to control Ma in finishing pigs. A possible Ma control system which includes a serodiagnostic test and a penalty on finishing pigs in herds detected with Ma infection was modelled. Using a dynamic optimization model and a grid search of deliveries of herds from pig producers to slaughterhouse, optimal control measures for pig producers and optimal penalty values for deliveries with increased Ma risk were identified for different sensitivity and specificity values. Results showed that higher sensitivity and lower specificity induced use of more intense control measures and resulted in higher pig producer costs and lower Ma seroprevalence. The minimal penalty value needed to comply with a threshold for Ma seroprevalence in finishing pigs at slaughter was lower at higher sensitivity and lower specificity. With imperfect specificity a larger sample size decreased pig producer incentives to control Ma seroprevalence, because the higher number of false positives resulted in an increased probability of rejecting a batch of finishing pigs irrespective of whether the pig producer applied control measures. We conclude that test sensitivity and specificity must be considered in incentive system design to induce pig producers to control Ma in finishing pigs with minimum negative effects.


Subject(s)
Animal Husbandry , Serologic Tests/methods , Swine Diseases/epidemiology , Swine Diseases/prevention & control , Tuberculosis/veterinary , Abattoirs , Animal Husbandry/economics , Animal Husbandry/methods , Animals , Models, Biological , Mycobacterium avium/isolation & purification , Prevalence , Sensitivity and Specificity , Seroepidemiologic Studies , Serologic Tests/veterinary , Swine , Swine Diseases/microbiology , Tuberculosis/epidemiology , Tuberculosis/microbiology , Tuberculosis/prevention & control
17.
Ultramicroscopy ; 126: 77-84, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23500191

ABSTRACT

The polarity of epitaxial AlN film grown on (0001)6H-SiC and dislocation core structures in the film have been studied using a 200 kV LaB6 high-resolution transmission electron microscope of point resolution about 0.2 nm. A posterior image processing technique, the image deconvolution, was utilized to transform a single [21¯1¯0] image that does not intuitively represent the structure into the projected structure map. The adjacent Al and N projected atomic columns with the interatomic distance 0.109 nm can be distinguished from each other by analyzing the image contrast change with the sample thickness based on the pseudo-weak phase object approximation. This makes possible to derive the polarity and core structures of partial dislocations in the epitaxial AlN film at atomic level from a single image without relying on any other additional structure information. The atomic configurations for two partial dislocations containing a 10-atom ring and a 12-atom ring, respectively, have been attained. The method is available for II-VI and other III-V compounds. Its principle and procedure are briefly introduced.

18.
J Appl Microbiol ; 114(4): 956-63, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23279192

ABSTRACT

AIMS: Chitosan has gained wide applications in the food industry and biomedical field owing to its biodegradability, biocompatibility, nontoxicity and its antimicrobial activity against a wide spectrum of micro-organisms. However, the methods used to investigate antimicrobial effects of chitosan vary considerably among studies, making comparisons difficult. METHODS AND RESULTS: One diffusion (disc diffusion) and two dilution (agar dilution and broth microdilution) methods commonly used in clinical laboratories to assess microbial susceptibility/resistance to antimicrobial agents were comparatively used to determine the antimicrobial activity of two water-soluble chitosan derivatives (molecular weights of 43 and 67 kDa) against 31 representative foodborne pathogens. When tested at 1.6% for the 43-kDa chitosan and 3.2% for the 67-kDa chitosan, by disc diffusion, approximately 10- to 11-mm-diameter inhibition zones were observed for all of the bacterial groups, except for Salmonella tested for the 67-kDa chitosan where no inhibition zone was observed. By agar dilution and broth microdilution, the minimal inhibitory concentration (MIC) values varied largely dependent upon the molecular weight of chitosan, bacterial genus/species and the testing method. The agreement between MIC values obtained by the two methods was poor, with broth microdilution generally having lower MIC values than agar dilution. Regardless of the testing method, Salmonella strains were the least susceptible among Gram-negative strains for both chitosans, followed by Escherichia coli and Vibrio. CONCLUSIONS: Besides chitosan's molecular weight and bacterial genus/species, the antimicrobial activity of chitosan was also influenced largely by the susceptibility testing method used. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study that comparatively evaluated these diffusion and dilution methods, particularly two quantitative methods (agar dilution and broth microdilution), to assess the antimicrobial activity of two water-soluble chitosans against a large number of foodborne pathogens. The study highlights the need for standardized methods to be used in evaluating chitosan's antimicrobial properties in future studies.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Chitosan/pharmacology , Microbial Sensitivity Tests/methods , Chitosan/chemistry , Diffusion , Food Microbiology/methods , Water
19.
Cell Death Differ ; 20(3): 456-64, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23154388

ABSTRACT

Activating and inhibitory receptors control natural killer (NK) cell activity. T-cell immunoglobulin and ITIM (immunoreceptor tyrosine-based inhibition motif) domain (TIGIT) was recently identified as a new inhibitory receptor on T and NK cells that suppressed their effector functions. TIGIT harbors the immunoreceptor tail tyrosine (ITT)-like and ITIM motifs in its cytoplasmic tail. However, how its ITT-like motif functions in TIGIT-mediated negative signaling is still unclear. Here, we show that TIGIT/PVR (poliovirus receptor) engagement disrupts granule polarization leading to loss of killing activity of NK cells. The ITT-like motif of TIGIT has a major role in its negative signaling. After TIGIT/PVR ligation, the ITT-like motif is phosphorylated at Tyr225 and binds to cytosolic adapter Grb2, which can recruit SHIP1 to prematurely terminate phosphatidylinositol 3-kinase (PI3K) and MAPK signaling, leading to downregulation of NK cell function. In support of this, Tyr225 or Asn227 mutation leads to restoration of TIGIT/PVR-mediated cytotoxicity, and SHIP1 silencing can dramatically abolish TIGIT/PVR-mediated killing inhibition.


Subject(s)
GRB2 Adaptor Protein/metabolism , Killer Cells, Natural/immunology , Phosphoric Monoester Hydrolases/metabolism , Receptors, Immunologic/metabolism , Amino Acid Motifs , Cell Line , GRB2 Adaptor Protein/antagonists & inhibitors , GRB2 Adaptor Protein/genetics , Humans , Inositol Polyphosphate 5-Phosphatases , Mitogen-Activated Protein Kinase Kinases/metabolism , Mutation , Phosphatidylinositol 3-Kinases/metabolism , Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases , Phosphoric Monoester Hydrolases/antagonists & inhibitors , Phosphoric Monoester Hydrolases/genetics , Phosphorylation , RNA Interference , RNA, Small Interfering/metabolism , Receptors, Immunologic/chemistry , Receptors, Immunologic/genetics , Receptors, Virus/metabolism , Signal Transduction
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