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21.
Sarunporn Tandhavanant Aunchalee Thanwisai Direk Limmathurotsakul Sunee Korbsrisate Nicholas PJ Day Sharon J Peacock Narisara Chantratita 《BMC microbiology》2010,10(1):303
Background
Primary diagnostic cultures from patients with melioidosis demonstrate variation in colony morphology of the causative organism, Burkholderia pseudomallei. Variable morphology is associated with changes in the expression of a range of putative virulence factors. This study investigated the effect of B. pseudomallei colony variation on survival in the human macrophage cell line U937 and under laboratory conditions simulating conditions within the macrophage milieu. Isogenic colony morphology types II and III were generated from 5 parental type I B. pseudomallei isolates using nutritional limitation. Survival of types II and III were compared with type I for all assays. 相似文献22.
Rachaneeporn Tiyawisutsri Matthew TG Holden Sarinna Tumapa Sirirat Rengpipat Simon R Clarke Simon J Foster William C Nierman Nicholas PJ Day Sharon J Peacock 《BMC microbiology》2007,7(1):19
Background
The bacterial biothreat agents Burkholderia mallei and Burkholderia pseudomallei are the cause of glanders and melioidosis, respectively. Genomic and epidemiological studies have shown that B. mallei is a recently emerged, host restricted clone of B. pseudomallei. 相似文献23.
The effect of moisture content and temperature on water diffusion into a modified high amylose (< or = 90%) maize thermoplastic starch blend was investigated. Gravimetric and magnetic resonance imaging (MRI) studies were conducted to elucidate the diffusion mechanism and diffusion coefficients for this system. The diffusion coefficient data demonstrated that the rate of water diffusion into this blend was significantly dependent upon temperature and moisture content. Water diffusion was faster at higher temperatures and generally for samples stored at higher relative humidity environments. It was revealed from the gravimetric data that water diffusion into this starch blend was Fickian; however, further analysis of the MRI images found that the water diffusion mechanism was exponentially dependent on the concentration. This result was determined by comparing experimental water concentration profiles to a theoretical model calculated using the implicit Crank-Nicolson finite difference method. 相似文献
24.
Background
Current techniques used to obtain lung samples have significant limitations and do not provide reproducible biomarkers of inflammation. We have developed a novel technique that allows multiple sampling methods from the same area (or multiple areas) of the lung under direct bronchoscopic vision. It allows collection of mucosal lining fluid and bronchial brushing from the same site; biopsy samples may also be taken. The novel technique takes the same time as standard procedures and can be conducted safely.Methods
Eight healthy smokers aged 40–65 years were included in this study. An absorptive filter paper was applied to the bronchial mucosa under direct vision using standard bronchoscopic techniques. Further samples were obtained from the same site using bronchial brushings. Bronchoalveolar lavage (BAL) was obtained using standard techniques. Chemokine (C-C Motif) Ligand 20 (CCL20), CCL4, CCL5, Chemokine (C-X-C Motif) Ligand 1 (CXCL1), CXCL8, CXCL9, CXCL10, CXCL11, Interleukin 1 beta (IL-1β), IL-6, Vascular endothelial growth factor (VEGF), Matrix metalloproteinase 8 (MMP-8) and MMP-9 were measured in exudate and BAL. mRNA was collected from the bronchial brushings for gene expression analysis.Results
A greater than 10 fold concentration of all the biomarkers was detected in lung exudate in comparison to BAL. High yield of good quality RNA with RNA integrity numbers (RIN) between 7.6 and 9.3 were extracted from the bronchial brushings. The subset of genes measured were reproducible across the samples and corresponded to the inflammatory markers measured in exudate and BAL.Conclusions
The bronchoabsorption technique as described offers the ability to sample lung fluid direct from the site of interest without the dilution effects caused by BAL. Using this method we were able to successfully measure the concentrations of biomarkers present in the lungs as well as collect high yield mRNA samples for gene expression analysis from the same site. This technique demonstrates superior sensitivity to standard BAL for the measurement of biomarkers of inflammation. It could replace BAL as the method of choice for these measurements. This method provides a systems biology approach to studying the inflammatory markers of respiratory disease progression.Trial registration
NHS Health Research Authority (13/LO/0256). 相似文献25.
AB Chang NC Cox J Purcell JM Marchant PJ Lewindon GJ Cleghorn LC Ee GD Withers MK Patrick J Faoagali 《Respiratory research》2005,6(1):1-5
Background and methods
Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR.Results
We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 × 105 viral copies/ml in nasal lavage and 1.88 × 105 viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD.Conclusion
HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely. 相似文献26.
Donnelly MJ McCall PJ Lengeler C Bates I D'Alessandro U Barnish G Konradsen F Klinkenberg E Townson H Trape JF Hastings IM Mutero C 《Malaria journal》2005,4(1):12-5
There are already 40 cities in Africa with over 1 million inhabitants and the United Nations Environmental Programme estimates that by 2025 over 800 million people will live in urban areas. Recognizing that malaria control can improve the health of the vulnerable and remove a major obstacle to their economic development, the Malaria Knowledge Programme of the Liverpool School of Tropical Medicine and the Systemwide Initiative on Malaria and Agriculture convened a multi-sectoral technical consultation on urban malaria in Pretoria, South Africa from 2nd to 4th December, 2004. The aim of the meeting was to identify strategies for the assessment and control of urban malaria. This commentary reflects the discussions held during the meeting and aims to inform researchers and policy makers of the potential for containing and reversing the emerging problem of urban malaria. 相似文献
27.
Nellist M Burgers PC van den Ouweland AM Halley DJ Luider TM 《Biochemical and biophysical research communications》2005,333(3):818-826
Tuberous sclerosis complex (TSC) is an autosomal dominant benign tumour syndrome caused by mutations to either the TSC1 or TSC2 tumour suppressor gene. The TSC1 and TSC2 gene products, TSC1 and TSC2, form a protein complex that integrates inputs from multiple signalling cascades to inactivate the small GTPase rheb, and thereby inhibit mTOR-dependent cell growth. We have used matrix-assisted laser desorption/ionisation time-of-flight and Fourier transform mass spectrometry to identify TSC1 and TSC2 phosphorylation sites and candidate TSC1 and TSC2 interacting proteins. We identified three sites of TSC2 phosphorylation and a novel site of TSC1 phosphorylation, and investigated the roles of these sites in regulating the activity of the TSC1-TSC2 complex. In addition, we identified three TSC1-TSC2 interacting proteins, including DOCK7 a putative rhebGEF. 相似文献
28.
Estimates of diet derived from stable isotope analyses are sensitive to the accuracy of corrections made for diet-tissue fractionation.
In particular, diet-tissue fractionation in reindeer Rangifer tarandus may be expected to differ significantly from the generic values often used in stable isotope dietary calculations, given
the known values obtained from other ungulates and the complex digestive system and nutrient recycling characteristic of the
species. We fed domestic reindeer a homogenous artificial diet of known isotopic value in order to directly determine diet-tissue
isotopic fractionation of carbon and nitrogen, the main elements used in stable isotope dietary analyses. Diet-tissue fractionation
values for blood plasma were +3.5 ± 0.1‰ (δ13C) and +4.2 ± 0.3‰ (δ15N). Diet-tissue fractionation values for whole blood were +3.7 ± 0.2‰ (δ13C) and +2.5 ± 0.3‰ (δ15N). Metabolic turnover rates were clearly sufficient for complete tissue replacement over the period of artificial feeding
for blood plasma, but may not have been so for whole blood, especially for δ15N. Our values, except for whole blood δ15N, differ considerably from the generic values often used in dietary studies and interspecific comparisons of trophic niche.
The results underline the importance of obtaining as specific as possible fractionation values for the species, tissue, and
in some cases sex and physiological status of animals under examination, and the potential problems associated with assuming
‘generic’ fractionation values when comparing species, especially where digestive processes are dissimilar. 相似文献
29.
30.
Arun V. Holden Oleg V. Aslanidi Alan P. Benson Richard H. Clayton Graeme Halley Pan Li Wing Chiu Tong 《Journal of biological physics》2006,32(3-4):355-368
Methods for the experimental and clinical investigation of cardiac arrhythmias are limited to inferring propagation within
the myocardium, from surface measurements, or from electrodes at a few sites within the cardiac wall. Biophysically and anatomically
detailed computational models of cardiac tissues offer a powerful way for studying the electrical propagation processes and
arrhythmias within the virtual heart. We use virtual tissues to study and visualise the effects of patho- and physiological
conditions, and pharmacological interventions on transmural propagation in the virtual ventricular walls. Class III drug actions
are quantitatively explained by changes induced in the transmural dispersion of action potential duration. We illustrate the
automated construction of a virtual anisotropic ventricle from Diffusion Tensor MRI for individual hearts, and use it to explore
mechanisms leading to ventricular fibrillation. The virtual ventricular wall provides an effective tool for exploring, evaluating
and visualising processes during the initiation and maintenance of ventricular arrhythmias. 相似文献