Enzyme immunoassay for semicarbazide - The nitrofuran metabolite and food contaminant

Semicarbazide (SEM), the marker residue for the banned nitrofuran veterinary antibiotic nitrofurazone (NFZ), has been detected regularly in foods (47% of recent nitrofuran EU Rapid Alerts involve SEM). However, the validity of SEM as a definitive marker for NFZ has been undermined by SEM arising from other sources including azodicarbonamide, a plastics blowing agent and flour treatment additive. An inexpensive screening test for SEM in food matrices is needed-all SEM testing currently uses expensive LC-MS/MS instrumentation. We now report the first production of antibodies against derivatised SEM. A novel carboxyphenyl SEM derivative was used to raise a polyclonal antibody that has been incorporated into a semi-quantitative microtitre plate ELISA, validated according to the criteria set out in Commission Decision 2002/657/EC, for use with chicken muscle. The antibody is highly specific for derivatised SEM, cross-reactivity being 1.7% with NFZ and negligible with a wide range of other nitrofurans and poultry drugs. Samples are derivatised with o-nitrobenzaldehyde and simultaneously protease digested before extraction by cation exchange SPE. The ELISA has a SEM detection capability (CC beta) of 0.25 mu g kg(-1) when a threshold of 0.21 mu g kg(-1) is applied to the selection of samples for confirmation (lowest observed 0.25 mu g kg(-1) fortified sample, n = 20), thus satisfying the EU nitrofurans' minimum required performance limit of 1 mu g kg(-1). N-FZ-incurred muscles (12) containing SEM at 0.5-5.0 mu g kg(-1) by LC-MS/MS, all screened positive by this ELISA protocol which is also applicable to egg and chicken liver. (C) 2007 Elsevier BN. All rights reserved.

Toenail trace element status and risk of Barrett's oesophagus and oesophageal adenocarcinoma. Results from the FINBAR study

Trace elements have been cited as both inhibitory and causative agents of cancer but importantly exposure to them is potentially modifiable. Our study aimed to examine toenail trace element status and risk of Barrett's oesophagus (BO) and oesophageal adenocarcinoma (OAC). Toenail clippings from each hallux were obtained from 638 participants of the FINBAR (Factors Influencing the Barrett's Adenocarcinoma Relationship) study comprising 221 healthy controls, 98 reflux oesophagitis, 182 BO and 137 OAC cases. The concentrations of eight toenail trace elements were determined using instrumental neutron activation analysis. Using multivariable adjusted logistic regression analysis, odds ratios (OR) and 95% confidence intervals (CIs) were calculated within tertiles of trace element concentrations. A twofold increased risk of BO was observed, but not OAC, among individuals in the highest tertile of toenail zinc status OR 2.21 (95% CI, 1.11-4.40). A higher toenail selenium status was not associated with risk of OAC OR 0.94 (95% CI, 0.44-2.04) or BO OR 0.89 (95% CI, 0.37-2.12). A borderline significant increased risk of BO was detected with a higher toenail cobalt concentration, OR 1.97 (95% CI, 1.01-3.85). No association was found between toenail levels of chromium, cerium, mercury and OAC or BO risk. This is the first case-control study to investigate a variety of trace elements in relation to OAC and BO risk. Despite antioxidant and proapoptotic properties, no associations were found with selenium. Higher concentrations of toenail zinc and cobalt were associated with an increased BO risk, but not OAC. These findings need confirmation in prospective analysis.

Selective Orthosteric Free Fatty Acid Receptor 2 (FFA2) Agonists IDENTIFICATION OF THE STRUCTURAL AND CHEMICAL REQUIREMENTS FOR SELECTIVE ACTIVATION OF FFA2 VERSUS FFA3

Free fatty acid receptor 2 (FFA2; GPR43) is a G protein-coupled seven-transmembrane receptor for short-chain fatty acids (SCFAs) that is implicated in inflammatory and metabolic disorders. The SCFA propionate has close to optimal ligand efficiency for FFA2 and can hence be considered as highly potent given its size. Propionate, however, does not discriminate between FFA2 and the closely related receptor FFA3 (GPR41). To identify FFA2-selective ligands and understand the molecular basis for FFA2 selectivity, a targeted library of small carboxylic acids was examined using holistic, label-free dynamic mass redistribution technology for primary screening and the receptor-proximal G protein [S-35] guanosine 5'-(3-O-thio) triphosphate activation, inositol phosphate, and cAMP accumulation assays for hit confirmation. Structure-activity relationship analysis allowed formulation of a general rule to predict selectivity for small carboxylic acids at the orthosteric binding site where ligands with substituted sp(3)-hybridized alpha-carbons preferentially activate FFA3, whereas ligands with sp(2)- or sp-hybridized alpha-carbons prefer FFA2. The orthosteric binding mode was verified by site-directed mutagenesis: replacement of orthosteric site arginine residues by alanine in FFA2 prevented ligand binding, and molecular modeling predicted the detailed mode of binding. Based on this, selective mutation of three residues to their non-conserved counterparts in FFA3 was sufficient to transfer FFA3 selectivity to FFA2. Thus, selective activation of FFA2 via the orthosteric site is achievable with rather small ligands, a finding with significant implications for the rational design of therapeutic compounds selectively targeting the SCFA receptors.

EXPRESSION OF THE INFLAMMATORY REGULATOR A20 CORRELATES WITH LUNG FUNCTION IN PATIENTS WITH CYSTIC FIBROSIS

Abstract: Background: A20 and TAX1BP1 interact to negatively regulate NF-
-driven inflammation. A20 expression is altered in F508del/F508del
patients. Here we explore the effect of CFTR and CFTR genotype on A20 and
TAX1BP1expression. The relationship with lung function is also assessed.
Methods: Primary Nasal Epithelial cells (NECs) from CF patients
(F508del/F508del, n=8, R117H/F508del, n=6) and Controls (age-matched,
n=8), and 16HBE14o- cells were investigated. A20 and TAX1BP1 gene
expression was determined by qPCR.
Results: Silencing of CFTR reduced basal A20 expression. Following LPS
stimulation A20 and TAX1BP1 expression was induced in control NECs and
reduced in CF NECs, broadly reflecting the CF genotype: F508del/F508del
had lower expression than R117H/F508del. A20, but not TAX1BP1 expression,
was proportional to FEV1 in all CF patients (r=0.968, p<0.001).
Conclusions: A20 expression is reduced in CF and is proportional to FEV1.
Pending confirmation in a larger study, A20 may prove a novel predictor
of CF inflammation/disease severity.

Optimizing the balance between false positive and false negative error probabilities of confirmatory methods for the detection of veterinary drug residues

GC-MS data on veterinary drug residues in bovine urine are used for controlling the illegal practice of fattening cattle. According to current detection criteria, peak patterns of preferably four ions should agree within 10 or 20% from a corresponding standard pattern. These criteria are rigid, rather arbitrary and do not match daily practice. A new model, based on multivariate modeling of log peak abundance ratios, provides a theoretical basis for the identification of analytes and optimizes the balance between the avoidance of false positives and false negatives. The performance of the model is demonstrated on data provided by five laboratories, each supplying GC-MS measurements on the detection of clenbuterol, dienestrol and 19 beta-nortestosterone in urine. The proposed model shows a better performance than confirmation by using the current criteria and provides a statistical basis for inspection criteria in terms of error probabilities.

The systematic development of an innovative DVD to raise awareness of preconception care

The purpose of this article is to describe the design, development and process evaluation of a preconception counselling resource (a DVD) for women with pre-gestational diabetes. DVD design and development centred on two key stakeholders ('DVD user group' and 'professional advisory group') working alongside a professional multimedia company. The DVD user group provided feedback on preferred DVD style, and informed modifications and improvements. The professional advisory group prepared the script, and ensured content and face validity. Evaluation of the DVD's acceptability and usefulness was assessed among women with diabetes via a postal questionnaire. Development phase: the resulting DVD is a 45-minute programme with three parts, featuring eight women with diabetes sharing their views and experiences, alongside an evidence-based commentary. The programme focuses on the importance of preventing an unplanned pregnancy (highlighting contraception) and on essential planning advice. Evaluation phase: 97 women (89 with type 1 and 8 with type 2 diabetes) evaluated the DVD using a rating scale of 0-10. Mean (SD) scores were: 9.1 (1.3) for quality; 9.0 (1.4) for content; 8.8 (1.5) for interest; 8.7 (1.8) for usefulness; 7.8 (2.2) for knowledge acquisition; and 8.0 (2.1) for knowledge confirmation. This combined user and multi-professional advisory group approach has produced an innovative and highly acceptable preconception counselling resource for women with diabetes. The development process and outcome evaluation are an important point of reference for future educational programmes. Future research will evaluate the impact of this preconception counselling resource on pregnancy planning indicators and pregnancy outcome.

Pedometer-driven walking for chronic low back pain:A feasibility randomized controlled trial

OBJECTIVES: To evaluate the feasibility of an RCT of a pedometer-driven walking program and education/advice to remain active compared with education/advice only for treatment of chronic low back pain (CLBP). METHODS: Fifty-seven participants with CLBP recruited from primary care were randomly allocated to either: (1) education/advice (E, n=17) or (2) education/advice plus an 8-week pedometer-driven walking program (EWP, n=40). Step targets, actual daily step counts, and adverse events were recorded in a walking diary over the 8 weeks of intervention for the EWP group only. All other outcomes (eg, functional disability using the Oswestry Disability Questionnaire (ODQ), pain scores, physical activity (PA) measurement etc.) were recorded at baseline, week 9 (immediately post-intervention), and 6 months in both groups. RESULTS: The recruitment rate was 22% and the dropout rate was lower than anticipated (13% to 18% at 6 mo). Adherence with the EWP was high, 93% (n=37/40) walked for =6 weeks, and increased their steps/day [mean absolute increase in steps/d, 2776, 95% confidence interval (CI), 1996-3557] by 59% (95% CI, 40.73%-76.25%) from baseline. Mean percentage adherence with weekly step targets was 70% (95% CI, 62%-77%). Eight (20%) minor-related adverse events were observed in 13% (5/40) of the participants. The EWP group participants demonstrated an 8.2% point improvement [95% CI, -13 to -3.4] on the ODQ at 6 months compared with 1.6% points [95% CI, -9.3 to 6.1) for the E group (between group d=0.44). There was also a larger mean improvement in pain (d=0.4) and a larger increase in PA (d=0.59) at 6 months in EWP. DISCUSSION: This preliminary study demonstrated that a main RCT is feasible. EWP was safe and produced a real increase in walking; CLBP function and pain improved, and participants perceived a greater improvement in their PA levels. These improvements require confirmation in a fully powered RCT.

Association of retinal arteriolar dilatation with lower verbal memory::The Edinburgh Type 2 Diabetes Study

Abstract


AIMS/HYPOTHESIS:

Retinal vascular calibre changes may reflect early subclinical microvascular disease in diabetes. Because of the considerable homology between retinal and cerebral microcirculation, we examined whether retinal vascular calibre, as a proxy of cerebral microvascular disease, was associated with cognitive function in older people with type 2 diabetes.

METHODS:

A cross-sectional analysis of 954 people aged 60-75 years with type 2 diabetes from the population-based Edinburgh Type 2 Diabetes Study was performed. Participants underwent standard seven-field binocular digital retinal photography and a battery of seven cognitive function tests. The Mill Hill Vocabulary Scale was used to estimate pre-morbid cognitive ability. Retinal vascular calibre was measured from an image field with the optic disc in the centre using a validated computer-based program.

RESULTS:

After age and sex adjustment, larger retinal arteriolar and venular calibres were significantly associated with lower scores for the Wechsler Logical Memory test, with standardised regression coefficients -0.119 and -0.084, respectively (p?<?0.01), but not with other cognitive tests. There was a significant interaction between sex and retinal vascular calibre for logical memory. In male participants, the association of increased retinal arteriolar calibre with logical memory persisted (p?<?0.05) when further adjusted for vocabulary, venular calibre, depression, cardiovascular risk factors and macrovascular disease. In female participants, this association was weaker and not significant.

CONCLUSIONS/INTERPRETATION:

Retinal arteriolar dilatation was associated with poorer memory, independent of estimated prior cognitive ability in older men with type 2 diabetes. The sex interaction with stronger findings in men requires confirmation. Nevertheless, these data suggest that impaired cerebral arteriolar autoregulation in smooth muscle cells, leading to arteriolar dilatation, may be a possible pathogenic mechanism in verbal declarative memory decrements in people with diabetes.

Strawberries, Blueberries, and Cranberries in the Metabolic Syndrome:Clinical Perspectives

Emerging science supports therapeutic roles of strawberries, blueberries, and cranberries in metabolic syndrome, a prediabetic state characterized by several cardiovascular risk factors. Interventional studies reported by our group and others have demonstrated the following effects: strawberries lowering total and LDL-cholesterol, but not triglycerides, and decreasing surrogate biomarkers of atherosclerosis (malondialdehyde and adhesion molecules); blueberries lowering systolic and diastolic blood pressure and lipid oxidation and improving insulin resistance; and low-calorie cranberry juice selectively decreasing biomarkers of lipid oxidation (oxidized LDL) and inflammation (adhesion molecules) in metabolic syndrome. Mechanistic studies further explain these observations as up-regulation of endothelial nitric oxide synthase activity, reduction in renal oxidative damage, and inhibition of the activity of carbohydrate digestive enzymes or angiotensin-converting enzyme by these berries. These findings need confirmation in future studies with a focus on the effects of strawberry, blueberry, or cranberry intervention in clinical biomarkers and molecular mechanisms underlying the metabolic syndrome.

Strawberries decrease atherosclerotic markers in subjects with metabolic syndrome

Strawberries have been reported to be potent antioxidants and reduce cardiovascular risk factors, such as elevated blood pressure, hyperglycemia, dyslipidemia, and inflammation in limited studies. We hypothesized that freeze-dried strawberry supplementation will improve blood pressure, impaired glucose, dyslipidemia, or circulating adhesion molecules in obese subjects with metabolic syndrome, thereby lowering cardiovascular risk factors in these subjects. Twenty-seven subjects with metabolic syndrome (2 males and 25 females; body mass index, 37.5 +/- 2.15 kg/m(2); age, 47.0 +/- 3.0 years [means +/- SE]) consumed 4 cups of freeze-dried strawberry beverage (50 g freeze-dried strawberries approximately 3 cups fresh strawberries) or equivalent amounts of fluids (controls, 4 cups of water) daily for 8 weeks in a randomized controlled trial. Anthropometrics and blood pressure measurements, assessment of dietary intakes, and fasting blood draws were conducted at screen and 8 weeks of the study. Strawberry supplementation significantly decreased total and low-density lipoprotein cholesterol (5.8 +/- 0.2 to 5.2 +/- 0.2 mmol/L and 3.5 +/- 0.2 to 3.1 +/- 0.1 mmol/L, respectively [means +/- SE], P <.05) and small low-density lipoprotein particles using nuclear magnetic resonance-determined lipoprotein subclass profile vs controls at 8 weeks (794.6 +/- 94.0 to 681.8 +/- 86.0 nmol/L [means +/- SE], P <.05). Strawberry supplementation further decreased circulating levels of vascular cell adhesion molecule-1 vs controls at 8 weeks (272.7 +/- 17.4 to 223.0 +/- 14.0 ng/mL [means +/- SE], P <.05). Serum glucose, triglycerides, high-density lipoprotein cholesterol, blood pressure, and waist circumference were not affected. Thus, short-term freeze-dried strawberry supplementation improved selected atherosclerotic risk factors, including dyslipidemia and circulating adhesion molecules in subjects with metabolic syndrome, and these results need confirmation in future trials.

Confined Site Construction and its Impact on Personnel Productivity

Inner city, confined site construction is quickly becoming the norm within the construction sector. The aim of this paper is to identify and document the effect, if any, that a confined construction site environment has on the productivity of on-site personnel. In order to compile the relevant information and attain appropriate results on the matter in question, a qualitative analytical approach is adopted. This process incorporates multiple cases studies from Ireland, Northern Ireland and USA. From the resulting case studies, a minimum of three individual interviews and focus group seminars are conducted to aid in the collection of the data while also assisting in the confirmation of the factors identified from a critique of the relevant literature. From the resulting case studies and discussions, a list of the key issues pertaining to the on-site productivity of personnel emerged and is documented as follows; 1) Overcrowding of personnel at workstations, 2) Lack of space for the effective movement of personnel on-site, 3) Numerous trades working within the one space on-site. Through identifying the issues highlighted and proactively mitigating or eliminating the factors detailed, on-site management professionals can strive to ensure maximum productivity from the industry’s most important resource – people.

Vitamin D receptor gene variants and esophageal adenocarcinoma risk:A population-based case-control study

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.

The Next Generation Transit Survey (NGTS)

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.

Re-challenge chemotherapy with gemcitabine plus carboplatin in patients with non-small cell lung cancer

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.

Pyroelectric and piezoelectric scanning microscopy applied to reveal the bipolar state of 4-iodo-4 '-nitrobiphenyl (INBP)

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.