64 resultados para Confirmation.


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Purpose: Polymorphisms in the vitamin D receptor (VDR) gene may be of etiological importance in determining cancer risk. The aim of this study was to assess the association between common VDR gene polymorphisms and esophageal adenocarcinoma (EAC) risk in an all-Ireland population-based case-control study. Methods: EAC cases and frequency-matched controls by age and gender recruited between March 2002 and December 2004 throughout Ireland were included. Participants were interviewed, and a blood sample collected for DNA extraction. Twenty-seven single nucleotide polymorphisms in the VDR gene were genotyped using Sequenom or TaqMan assays while the poly(A) microsatellite was genotyped by fluorescent fragment analysis. Unconditional logistic regression was applied to assess the association between VDR polymorphisms and EAC risk. Results: A total of 224 cases of EAC and 256 controls were involved in analyses. After adjustment for potential confounders, TT homozygotes at rs2238139 and rs2107301 had significantly reduced risks of EAC compared with CC homozygotes. In contrast, SS alleles of the poly(A) microsatellite had significantly elevated risks of EAC compared with SL/LL alleles. However, following permutation analyses to adjust for multiple comparisons, no significant associations were observed between any VDR gene polymorphism and EAC risk. Conclusions: VDR gene polymorphisms were not significantly associated with EAC development in this Irish population. Confirmation is required from larger studies. © Springer Science+Business Media, LLC 2011.

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The Next Generation Transit Survey (NGTS) is a new ground-based sky survey designed to find transiting Neptunes and super-Earths. By covering at least sixteen times the sky area of Kepler we will find small planets around stars that are sufficiently bright for radial velocity confirmation, mass determination and atmospheric characterisation. The NGTS instrument will consist of an array of twelve independently pointed 20cm telescopes fitted with red-sensitive CCD cameras. It will be constructed at the ESO Paranal Observatory, thereby benefiting from the very best photometric conditions as well as follow up synergy with the VLT and E-ELT. Our design has been verified through the operation of two prototype instruments, demonstrating white noise characteristics to sub-mmag photometric precision. Detailed simulations show that about thirty bright super-Earths and up to two hundred Neptunes could be discovered. Our science operations are due to begin in 2014.

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Despite recent improvements to current therapies and the emergence of novel agents to manage advanced non-small cell lung cancer (NSCLC), the patients' overall survival remains poor. Re-challenging with first-line chemotherapy upon relapse is common in the management of small cell lung cancer but is not well reported for advanced NSCLC. NSCLC relapse has been attributed to acquired drug resistance, but the repopulation of sensitive clones may also play a role, in which case re-challenge may be appropriate. Here, we report the results of re-challenge with gemcitabine plus carboplatin in 22 patients from a single institution who had previously received gemcitabine plus platinum in the first-line setting and had either partial response or a progression-free interval of longer than 6 months. In this retrospective study, the charts of patients who underwent second-line chemotherapy for NSCLC in our cancer center between January 2005 and April 2010 were reviewed. All the patients who received a combination of gemcitabine and carboplatin for re-challenge were included in the study. These patients were offered second-line treatment on confirmation of clear radiological disease progression. The overall response rate was 15% and disease control rate was 75%. The median survival time was 10.4 months, with 46% of patients alive at 1 year. These results suggest that re-challenge chemotherapy should be considered in selected patients with radiological partial response or a progression-free survival of longer than 6 months to the initial therapy.

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Two recent scanning probe techniques were applied to investigate the bipolar twin state of 4-iodo-4'-nitrobiphenyl (INBP) crystals. Solution grown crystals of INBP show typically a morphology which does not express that of a mono-domain polar structure (Fdd2, mm2). From previous X-ray diffraction a twinning volume ratio of similar to 70 : 30 is now explained by two unipolar domains (Flack parameter: 0.075(29)) of opposite orientation of the molecular dipoles, joined by a transition zone showing a width of similar to 140 mm. Scanning pyroelectric microscopy (SPEM) demonstrates a continuous transition of the polarization P from +P into -P across the zone. Application of piezoelectric force microscopy (PFM) confirms unipolar alignment of INBP molecules down to a resolution of similar to 20 nm. A previously proposed real structure for INBP crystals built from lamellae with antiparallel alignment is thus rejected. Anomalous X-ray scattering was used to determine the absolute molecular orientation in the two domains. End faces of the polar axis 2 are thus made up by NO2 groups. Using a previously determined negative pyroelectric coefficient pc leads to a confirmation also by a SPEM analysis. Calculated values for functional group interactions (D...A), (A...A), (D...D) and the stochastic theory of polarity formation allow us to predict that NO2 groups should terminate corresponding faces. Following the present analysis, INBP may represent a first example undergoing dipole reversal upon growth to end up in a bipolar state.

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Heterocyclic aromatic amines (HCA) are carcinogenic mutagens formed during cooking of proteinaceous foods, particularly meat. To assist in the ongoing search for biomarkers of HCA exposure in blood, a method is described for the extraction from human plasma of the most abundant HCAs: 2-Amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) (and its isomer 7,8-DiMeIQx), using Hollow Fibre Membrane Liquid-Phase Microextraction. This technique employs 2.5 cm lengths of porous polypropylene fibres impregnated with organic solvent to facilitate simultaneous extraction from an alkaline aqueous sample into a low volume acidic acceptor phase. This low cost protocol is extensively optimised for fibre length, extraction time, sample pH and volume. Detection is by UPLC-MS/MS using positive mode electrospray ionisation with a 3.4 min runtime, with optimum peak shape, sensitivity and baseline separation being achieved at pH 9.5. To our knowledge this is the first description of HCA chromatography under alkaline conditions. Application of fixed ion ratio tolerances for confirmation of analyte identity is discussed. Assay precision is between 4.5 and 8.8% while lower limits of detection between 2 and 5 pg/mL are below the concentrations postulated for acid-labile HCA-protein adducts in blood.

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An endocrine disruptor (ED) is an exogenous compound that interferes with the body's endocrine system. Exposure to EDs may result in adverse health effects such as infertility and cancer. EDs are composed of a vast group of chemicals including compounds of natural origin such as phytoestrogens or mycotoxins and a wide range of man-made chemicals such as pesticides. Synthetic compounds may find their way into the food chain where a number of them can biomagnify. Additionally, processing activities and food contact materials may add further to the already existing pool of food contaminants. Thus, our diet is considered to be one of the main exposure routes to EDs. Some precautionary legislation has already been introduced to control production and/or application of some persistent organic pollutants with ED characteristics. However, newly emerging EDs with bioaccumulative properties have recently been reported to appear at lower tiers of the food chain but have not been monitored at the grander scale. Milk and dairy products are a major component of our diet, thus it is important to monitor them for EDs. However, most methods developed to date are devoted to one group of compounds at a time. The UHPLC-MS/MS method described here has been validated according to EC decision 2002/657/EC and allows simultaneous extraction, detection, quantitation and confirmation of 19 EDs in milk. The method calibration range is between 0.50 and 20.0 μg kg with coefficients of determination above 0.99 for all analytes. Precision varied from 4.7% to 23.4% in repeatability and reproducibility studies. Established CCα and CCβ values (0.11-0.67 μg kg) facilitate fast, reliable, quantitative and confirmatory analysis of sub μg kg levels of a range of EDs in milk.

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Purpose:The aim of this study was to determine whether mutations in mitochondrial DNA play a role in high-pressure primary open-angle glaucoma (OMIM 137760) by analyzing new data from massively parallel sequencing of mitochondrial DNA.
Methods:Glaucoma patients with high-tension primary open-angle glaucoma and ethnically matched and age-matched control subjects without glaucoma were recruited. The entire human mitochondrial genome was amplified in two overlapping fragments by long-range polymerase chain reaction and used as a template for massively parallel sequencing on an Ion Torrent Personal Genome Machine. All variants were confirmed by conventional Sanger sequencing.
Results:Whole-mitochondrial genome sequencing was performed in 32 patients with primary open-angle glaucoma from India (n = 16) and Ireland (n = 16). In 16 of the 32 patients with primary open-angle glaucoma (50% of cases), there were 22 mitochondrial DNA mutations consisting of 7 novel mutations and 8 previously reported disease-associated sequence variants. Eight of 22 (36.4%) of the mitochondrial DNA mutations were in complex I mitochondrial genes.
Conclusion:Massively parallel sequencing using the Ion Torrent Personal Genome Machine with confirmation by Sanger sequencing detected a pathogenic mitochondrial DNA mutation in 50% of the primary open-angle glaucoma cohort. Our findings support the emerging concept that mitochondrial dysfunction results in the development of glaucoma and, more specifically, that complex I defects play a significant role in primary open-angle glaucoma pathogenesis.

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Signalling lymphocyte activation molecule (SLAM) has been identified as an immune cell receptor for the morbilliviruses, measles (MV), canine distemper (CDV), rinderpest and peste des petits ruminants (PPRV) viruses, while CD46 is a receptor for vaccine strains of MV. More recently poliovirus like receptor 4 (PVRL4), also known as nectin 4, has been identified as a receptor for MV, CDV and PPRV on the basolateral surface of polarised epithelial cells. PVRL4 is also up-regulated by MV in human brain endothelial cells. Utilisation of PVRL4 as a receptor by phocine distemper virus (PDV) remains to be demonstrated as well as confirmation of use of SLAM. We have observed that unlike wild type (wt) MV or wtCDV, wtPDV strains replicate in African green monkey kidney Vero cells without prior adaptation, suggesting the use of a further receptor. We therefore examined candidate molecules, glycosaminoglycans (GAG) and the tetraspan proteins, integrin β and the membrane bound form of heparin binding epithelial growth factor (proHB-EGF),for receptor usage by wtPDV in Vero cells. We show that wtPDV replicates in Chinese hamster ovary (CHO) cells expressing SLAM and PVRL4. Similar wtPDV titres are produced in Vero and VeroSLAM cells but more limited fusion occurs in the latter. Infection of Vero cells was not inhibited by anti-CD46 antibody. Removal/disruption of GAG decreased fusion but not the titre of virus. Treatment with anti-integrin β antibody increased rather than decreased infection of Vero cells by wtPDV. However, infection was inhibited by antibody to HB-EGF and the virus replicated in CHO-proHB-EGF cells, indicating use of this molecule as a receptor. Common use of SLAM and PVRL4 by morbilliviruses increases the possibility of cross-species infection. Lack of a requirement for wtPDV adaptation to Vero cells raises the possibility of usage of proHB-EGF as a receptor in vivo but requires further investigation.

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Recent molecular-typing studies suggest cross-infection as one of the potential acquisition pathways for Pseudomonas aeruginosa in patients with cystic fibrosis (CF). In Australia, there is only limited evidence of unrelated patients sharing indistinguishable P. aeruginosa strains. We therefore examined the point-prevalence, distribution, diversity and clinical impact of P. aeruginosa strains in Australian CF patients nationally. 983 patients attending 18 Australian CF centres provided 2887 sputum P. aeruginosa isolates for genotyping by enterobacterial repetitive intergenic consensus-PCR assays with confirmation by multilocus sequence typing. Demographic and clinical details were recorded for each participant. Overall, 610 (62%) patients harboured at least one of 38 shared genotypes. Most shared strains were in small patient clusters from a limited number of centres. However, the two predominant genotypes, AUST-01 and AUST-02, were widely dispersed, being detected in 220 (22%) and 173 (18%) patients attending 17 and 16 centres, respectively. AUST-01 was associated with significantly greater treatment requirements than unique P. aeruginosa strains. Multiple clusters of shared P. aeruginosa strains are common in Australian CF centres. At least one of the predominant and widespread genotypes is associated with increased healthcare utilisation. Longitudinal studies are now needed to determine the infection control implications of these findings.

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Phenotypic identification of Gram-negative bacteria from respiratory specimens of patients with cystic fibrosis carries a high risk of misidentification. Molecular identification techniques that use single-gene targets are also susceptible to error, including cross-reaction issues with other Gram-negative organisms. In this study, we have designed a Pseudomonas aeruginosa duplex real-time polymerase chain reaction (PCR) (PAduplex) assay targeting the ecfX and the gyrB genes. The PAduplex was evaluated against a panel of 91 clinical and environmental isolates that were presumptively identified as P. aeruginosa. The results were compared with those obtained using a commercial biochemical identification kit and several other P. aeruginosa PCR assays. The results showed that the PAduplex assay is highly suitable for routine identification of P. aeruginosa isolates from clinical or environmental samples. The 2-target format provides simultaneous confirmation of P. aeruginosa identity where both the ecfX and gyrB PCR reactions are positive and may also reduce the potential for false negatives caused by sequence variation in primer or probe targets.

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Cystic Fibrosis (CF) is a genetic disease featuring a chronic cycle of inflammation and infection in the airways of sufferers. Mutations lead to altered ion transport, which in turn causes dehydrated airways and reduced mucociliary clearance which predisposes the patient to infection, resulting in a severe immune response and tissue destruction (1). Airway dehydration is primarily caused by the hyperabsorption of sodium by the epithelial sodium channel (ENaC) (2). ENaC is activated by the action of a number of predominantly trypsin-like Channel Activating Proteases (CAPs) including prostasin, matriptase and furin (3). Additional proteases known to activate ENaC include human airway trypsin (3), plasmin, neutrophil elastase and chymotrypsin (4).

Activity profiling is a valuable technique which involves the use of small inhibitory molecules called Activity-Based Probes (ABPs) which can be used to covalently label the active site of proteases and provide a range of information regarding its structure, catalytic mechanism, location and function within biological systems. The development of novel ABPs for CAPs, would enhance understanding of the role of these proteases in CF airways disease and in particular their role in ENaC activation and airway dehydration. This project investigates the application of a range of novel broad-spectrum ABPs targeting the various subclasses of serine proteases, to include those proteases involved in ENaC activation. Additionally, the application of more selective ABPs in detecting specific serine proteases is investigated.

Compounds were synthesised by Solid-Phase Peptide Synthesis (SPPS) using a standard Fmoc/tBu strategy. Kinetic evaluation of synthesised ABPs against various serine proteases was determined by fluorogenic steady-state enzyme assays. Furthermore, application of ABPs and confirmation of irreversible nature of the compounds was carried out through SDS-PAGE and electroblotting techniques.

Synthesised compounds showed potent irreversible inhibition of serine proteases within their respective targeting class (NAP855 vs Trypsin k3/Ki = 2.60 x 106 M-1 min-1, NFP849 vs Chymotrypsin k3/Ki = 1.28 x 106 M-1 min-1 and NVP800 vs Neutrophil Elastase k3/Ki = 6.41 x 104 M-1 min-1). Furthermore ABPs showed little to no cross-reactivity between classes and so display selectivity between classes. The irreversible nature of compounds was further demonstrated through labelling of proteases, followed by separation and detection via SDS-PAGE and electroblotting techniques. Targeted labelling of active proteases only, was demonstrated by failure of ABPs to detect previously inactivated proteases. Extension of the substrate recognition site within probes resulted in an increased potency and selectivity in the detection of the target proteases. Successful detection of neutrophil elastase from CF sputum samples by NVP800, demonstrated the application of compounds within biological samples and their potential use in identifying further proteases involved in ENaC activation and airway dehydration in CF patients.

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OBJECTIVES: Microneedle (MN) arrays could offer a pain-free, minimally invasive approach to monitoring. This is envisaged to be particularly beneficial for younger patients, but parents' views to date are unknown. The aim of this study was to explore parental perceptions of MN-mediated ISF monitoring, as an alternative to the use of conventional blood sampling, and to understand the important factors for technique approval.

METHODS: Semi-structured interviews were conducted with parents with recent experience of a premature birth. Recruitment was through the Northern Ireland premature infant charity, Tinylife. Interviews progressed until data saturation was reached and thematic analysis employed.

KEY FINDINGS: The study included 16 parents. Parental support for MN-mediated monitoring was evident, alongside the unpopularity of traditional blood sampling in neonates. Factors facilitating MN approval included the opportunity for pain reduction, the simplicity of the procedure, the potential for increased parental involvement and the more favourable appearance, owing to the minute size of MNs and similarities with a sticking plaster. Confirmation of correct application, a pain-free patch removal and endorsement from trusted healthcare professionals were important.

CONCLUSION: These findings will inform researchers in the field of MN development and enlighten practitioners regarding parental distress resulting from conventional blood sampling. Further work is necessary to understand MN acceptability among practitioners. This work should assist in the development of an acceptable MN device and facilitate the reduction of parental distress.

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Microneedle (MN) arrays could offer an alternative method to traditional drug delivery and blood sampling methods. However, acceptance among key end-users is critical for new technologies to succeed. MNs have been advocated for use in children and so, paediatricians are key potential end-users. However, the opinions of paediatricians on MN use have been previously unexplored. The aim of this study was to investigate the views of UK paediatricians on the use of MN technology within neonatal and paediatric care. An online survey was developed and distributed among UK paediatricians to gain their opinions of MN technology and its use in the neonatal and paediatric care settings, particularly for MN-mediated monitoring. A total of 145 responses were obtained, with a completion response rate of 13.7 %. Respondents believed an alternative monitoring technique to blood sampling in children was required. Furthermore, 83 % of paediatricians believed there was a particular need in premature neonates. Overall, this potential end-user group approved of the MN technology and a MN-mediated monitoring approach. Minimal pain and the perceived ease of use were important elements in gaining favour. Concerns included the need for confirmation of correct application and the potential for skin irritation. The findings of this study provide an initial indication of MN acceptability among a key potential end-user group. Furthermore, the concerns identified present a challenge to those working within the MN field to provide solutions to further improve this technology. The work strengthens the rationale behind MN technology and facilitates the translation of MN technology from lab bench into the clinical setting.

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Anguina pacificae is a significant pest of Poa annua golf course greens in northern California. This study presents the first confirmed case of an A. pacificae infestation outside of North America, where the nematode's distribution is further restricted to a relatively limited coastal region. Species confirmation was made by morphometric and molecular methods and comparisons to closely related species including the European species, Anguina agropyri. The A. pacificae population detected on an Irish golf course was monitored over a 2-yr period and the life cycle compared with Californian population dynamics. A. pacificae was assessed for the potential risk of spreading to the local agricultural sector, in addition, the biosecurity risks from A. pacificae and plant parasitic nematodes in general were reviewed for northwest Europe.

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Purpose: Researchers have demonstrated associations between trauma and psychosis. Childhood trauma, in particular, appears to be an important determinant. Recently, bullying has become considered a traumatic experience in its own right. This review aims to analyse research with prospective designs, which will enable conclusions about whether or not bullying causes psychosis.

Methods: A systematic review of the literature was carried out independently by two reviewers. Eligibility and quality assessment criteria were applied. A meta-analysis and narrative synthesis were then completed.

Results: Ten studies met inclusion criteria. Four used data from the same large database, and were combined as one. The majority provided confirmation that bullying appears to cause later development of psychosis. A meta-analysis yielded an unadjusted odds ratio (OR) of 2.148 [95% confidence interval (CI) 1.140–4.044].

Conclusions: The studies reviewed here suggest that bullying does predict the later development of psychotic symptoms. What is lacking from the literature is adequate investigation into other potential mediating factors. The current review highlights the significant role of bullying within this complex interaction. Potential mediating variables are explored, including a dose–response effect for the severity and frequency of victimization. Suggestions for targeting intervention are also suggested alongside clinical implications and recommendations for future research.