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排序方式: 共有197条查询结果,搜索用时 15 毫秒
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.
Makoto Ogura Abraham D. Abernethy Ryan D. Blissett Karriann Ruggiero Sovanda Som J. Max Goodson Ralph Kent Apostolos G. Doukas Nikolaos S. Soukos 《World journal of microbiology & biotechnology》2007,23(11):1637-1646
Photomechanical waves (PW), the product of an intense light beam interaction with a target material, enhance molecular delivery
across biological membranes and skin. The ability to deliver methylene blue (MB), a fluorescent probe and photosensitizer,
into bacterial biofilms was demonstrated by applying PW on saliva-derived multi-species biofilms that were developed on agar
surfaces in 24-well plates. PW were generated with a Q-switched Nd:YAG laser and were directed into the biofilms in the presence
of 25 μg/ml MB. The biofilms were then irradiated with red light at 665 nm. After illumination, adherent bacteria were scraped
and spread over the surface of blood agar plates. Survival fractions were calculated by counting bacterial colonies. Microbial
analysis was performed via a colony lift method and a DNA checkerboard assay using whole genomic probes to 40 oral microorganisms.
Visual analysis by confocal scanning laser microscopy demonstrated that the application of PW enhanced the penetration depth
of MB in biofilms. Exposure to MB, PW and light led to a significant reduction of the mean levels of log10 CFU counts compared with the group that received MB and light (P = 0.006). The DNA checkerboard assay showed some benefit from PW-assisted phototargeting in 25 biofilm microorganisms relative
to phototreatment alone. Our data provide a basis for further exploration and optimization of PW parameters for complete eradication
of microorganisms in oral microcosm biofilms. 相似文献
23.
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.
David C Currow Morag Farquhar Alicia M Ward Gregory B Crawford Amy P Abernethy 《BMC pulmonary medicine》2011,11(1):1-11
Background
End-stage lung disease (ESLD) is a frequent cause of death. What are the differences in the supports needed by caregivers of individuals with ESLD at end of life versus other life-limiting diagnoses?Methods
The South Australian Health Omnibus is an annual, random, face-to-face, cross-sectional survey. In 2002, 2003 and 2005-2007, respondents were asked a range of questions about end-of-life care; there were approximately 3000 survey participants annually (participation rate 77.9%). Responses were standardised for the whole population. The families and friends who cared for someone with ESLD were the focus of this analysis. In addition to describing caring, respondents reported additional support that would have been helpful.Results
Of 1504 deaths reported, 145 (9.6%) were due to ESLD. The ESLD cohort were older than those with other 'expected' causes of death (> 65 years of age; 92.6% versus 70.6%; p < 0.0001) and were less likely to access specialised palliative care services (38.4% versus 61.9%; p < 0.0001). For those with ESLD, the mean caring period was significantly longer at 25 months (standard deviation (SD) 24) than for 'other diagnoses' (15 months; SD 18; p < 0.0001). Domains where additional support would have been useful included physical care, information provision, and emotional and spiritual support.Conclusions
Caregiver needs were similar regardless of the underlying diagnosis although access to palliative care specialist services occurred less often for ESLD patients. This was despite significantly longer periods of time for which care was provided. 相似文献26.
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27.
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
28.
Kobrinsky E Tiwari S Maltsev VA Harry JB Lakatta E Abernethy DR Soldatov NM 《The Journal of biological chemistry》2005,280(13):12474-12485
Voltage-gated Ca(v)1.2 channels are composed of the pore-forming alpha1C and auxiliary beta and alpha2delta subunits. Voltage-dependent conformational rearrangements of the alpha1C subunit C-tail have been implicated in Ca2+ signal transduction. In contrast, the alpha1C N-tail demonstrates limited voltage-gated mobility. We have asked whether these properties are critical for the channel function. Here we report that transient anchoring of the alpha1C subunit C-tail in the plasma membrane inhibits Ca2+-dependent and slow voltage-dependent inactivation. Both alpha2delta and beta subunits remain essential for the functional channel. In contrast, if alpha1C subunits with are expressed alpha2delta but in the absence of a beta subunit, plasma membrane anchoring of the alpha1C N terminus or its deletion inhibit both voltage- and Ca2+-dependent inactivation of the current. The following findings all corroborate the importance of the alpha1C N-tail/beta interaction: (i) co-expression of beta restores inactivation properties, (ii) release of the alpha1C N terminus inhibits the beta-deficient channel, and (iii) voltage-gated mobility of the alpha1C N-tail vis a vis the plasma membrane is increased in the beta-deficient (silent) channel. Together, these data argue that both the alpha1C N- and C-tails have important but different roles in the voltage- and Ca2+-dependent inactivation, as well as beta subunit modulation of the channel. The alpha1C N-tail may have a role in the channel trafficking and is a target of the beta subunit modulation. The beta subunit facilitates voltage gating by competing with the N-tail and constraining its voltage-dependent rearrangements. Thus, cross-talk between the alpha1C C and N termini, beta subunit, and the cytoplasmic pore region confers the multifactorial regulation of Ca(v)1.2 channels. 相似文献
29.
PJ Waller G Bernes L Rudby-Martin B-L Ljungström A Rydzik 《Acta veterinaria Scandinavica》2004,45(3):149
A pen study was conducted to assess the effect of providing daily copper mineral supplement, or copper wire particle (COWP)
capsules, on established or incoming mixed nematode infections in young sheep. For lambs with established (6 week old) infections,
COWP resulted in 97% and 56% reduction of the adult and early L4 stages of H. contortus, respectively, compared with controls (p < 0.001). Additionally there was a 74% reduction in Teladorsagia circumcincta infections in the COWP lambs compared with controls (p < 0.01). However, no effect was observed when COWP were given at the
commencement of a larval dosing period of 6 weeks. There was no significant effect of copper mineral supplement (given at
the recommended rate to prevent Cu deficiency) on either established, or developing parasite infections. In addition, a field
trial was conducted on a commercial farm to assess the effects of COWP in the management of recurrent H. contortus infections, but lack of parasites during the grazing season prevented an adequate assessment from being made. These results
indicate that there is little, if any, benefit from a parasite control standpoint in recommending copper therapy, specifically
to control parasites in Swedish sheep flocks. 相似文献
30.
Porcine submaxillary gland apomucin contains tandemly repeated, identical sequences of 81 residues 总被引:6,自引:0,他引:6
C S Timpte A E Eckhardt J L Abernethy R L Hill 《The Journal of biological chemistry》1988,263(2):1081-1088
A lambda gt11 cDNA library, prepared from porcine submaxillary gland mRNA, was screened with anti-apomucin IgG, and five antibody-reactive phage were isolated. The phage with the largest cDNA insert, designated lambda PSM103, was further characterized. Its fusion protein reacted with anti-apomucin IgG and was used to affinity purify antibodies that specifically reacted with apomucin, indicating that the protein shares antigenic determinants with apomucin. The nucleotide sequence of 1510 bases in the 3.7-kilobase cDNA insert of lambda PSM103 has been established, thereby giving a deduced amino acid sequence of 503 residues in apomucin, or about 45% of the molecule. The deduced sequence of the apomucin polypeptide was found to contain 4.8 tandemly repeated, identical sequences of 81 residues each. The presence of these uniquely repeated sequences was confirmed by restriction endonuclease digestion of DNA derived from lambda PSM103. The repeat sequence was also confirmed in apomucin by the isolation of an 81-residue tryptic peptide with an amino acid composition and an amino-terminal amino acid sequence (up to 44 residues) identical to those of the tandem repeat. Moreover, the peptide was isolated in 760% yield, indicating that the tandem repeat occurs at least eight times in apomucin. The presence of such a long repetitive region in the gene for apomucin raises the possibility for considerable polymorphism in the gene and a corresponding size heterogeneity of apomucin. The predicted secondary structure of the 503 residues confirms the earlier proposal that apomucin is an extended, nonglobular polypeptide. Although the sequences around 192 serine and threonine residues have been established in apomucin, a recognition sequence for the N-acetylgalactosaminyltransferase that initiates glycosylation of apomucin is not evident, except that the glycosylated residues occur in turns. 相似文献