Isolation of Salmonella spp. from Animal Feed.

The isolation of Salmonella from feed is challenging and adjustments need to be made in order to accurately isolate the pathogen from feed. This is due to the complex nature of the feed matrix, which is both porous and fibrous. The outlined method below contains the essential components of a successful Salmonella methodology for the analysis of feed that overcomes the limitations of currently available methods.

Gαq/p63RhoGEF interaction in RhoA/Rho kinase signaling: investigation in Gitelman's syndrome and implications with hypertension.

PURPOSE: Gitelman's syndrome (GS) presents normo-hypotension and absence of cardiovascular-renal remodeling despite high angiotensin II (Ang II), activation of renin-angiotensin-aldosterone system and is a human model of endogenous antagonism of Ang II signaling, opposite to hypertension. GS's clinical presentation leads to questions regarding what features might be responsible. One area of investigation involves Ang II signaling. In hypertensive patients, RhoA/Rho kinase (RhoA/ROCK) pathway activation by Ang II is involved in hypertension development/maintenance and induction of long-term consequences (cardiovascular-renal remodeling), while GS has reduced p63RhoGEF gene and protein levels and ROCK activity. Ang II signaling is mediated by Gαq, which interacts with p63RhoGEF via the α6-αN linker connecting p63RhoGEF's DH and PH domains acting as a conformational switch to activate RhoA/ROCK signaling. METHODS: We have investigated in GS patients, the presence of mutations in either p63RhoGEF's α6-αN linker domain and in Gαq's Ala253, Trp263, and Tyr356 residues, crucial for p63RhoGEF-Gαq interplay. RESULTS: No mutations have been found in specific aminoacids of p63RhoGEF α6-αN linker and Gαq, key for p63RhoGEF/Gαq interplay. CONCLUSIONS: Gitelman's syndrome normo/hypotension and lack of cardiovascular-renal remodeling are not due to mutations of p63RhoGEF α6-αN linker and Gαq interactions. This opens the way for investigations on different coding and no-coding regions (p63RhoGEF and Gαq promoters) and on altered transcriptional/post-transcriptional regulation. Clarification of how these biochemical/molecular mechanisms work/interact would provide insights into mechanisms involved in the GS's Ang II signaling fine tuning, in human physiology/pathophysiology in general and could also identify significant targets for intervention in the treatments of hypertension.

The temporal relations across burnout dimensions in athletes.

Burnout is a construct that has garnered considerable attention in sport psychology within recent years. Several hypothesized models regarding how the three dimensions (exhaustion, devaluation, and reduced sense of accomplishment) temporally relate to each other have been advanced. One proposal outlined by Maslach and Leiter suggests that exhaustion predicts devaluation which predicts reduced sense of accomplishment. However, there is no consensus among researchers as it has been argued that exhaustion predicts devaluation and reduced accomplishment separately. The aim of this study was to test multiple alternative hypotheses regarding the relationships of the burnout dimensions in athletes. Two samples of Swedish youth elite athletes with differing time spans between measurements were used. Specifically, one sample involved time-intensive measures collected every week over an eight-week period, and the other sample included four measurement points across an 18-month period. Results showed that none of the previously proposed models outlining the temporal relations of burnout dimensions were supported. Statistical analysis of the models including the cross-lagged predictions of dimensions did not have any statistically significant impact except when exhaustion negatively predicted devaluation between time 1 (month 0) and time 2 (month 6) in the 18-month sample; this relation faded in the following time points. Further, issues regarding the stability of devaluation and reduced sense of accomplishment emerged as their autocorrelation were very weak in the time-intensive sample. These findings raise a number of points for further theoretical and practical discussions about the athlete burnout construct.

Estimating cut points: A simple method for new wearables.

UNLABELLED: Wearable technology is readily available for continuous assessment due to a growing number of commercial devices with increased data capture capabilities. However, many commercial devices fail to support suitable parameters (cut points) derived from the literature to help quantify physical activity (PA) due to differences in manufacturing. A simple metric to estimate cut points for new wearables is needed to aid data analysis. OBJECTIVE: The purpose of this pilot study was to investigate a simple methodology to determine cut points based on ratios between sedentary behaviour (SB) and PA intensities for a new wrist worn device (PRO-Diary™) by comparing its output to a validated and well characterised 'gold standard' (ActiGraph™). STUDY DESIGN: Twelve participants completed a semi-structured (four-phase) treadmill protocol encompassing SB and three PA intensity levels (light, moderate, vigorous). The outputs of the devices were compared accounting for relative intensity. RESULTS: Count ratios (6.31, 7.68, 4.63, 3.96) were calculated to successfully determine cut-points for the new wrist worn wearable technology during SB (0-426) as well as light (427-803), moderate (804-2085) and vigorous (≥ 2086) activities, respectively. CONCLUSION: Our findings should be utilised as a primary reference for investigations seeking to use new (wrist worn) wearable technology similar to that used here (i.e., PRO-Diary™) for the purposes of quantifying SB and PA intensities. The utility of count ratios may be useful in comparing devices or SB/PA values estimated across different studies. However, a more robust examination is required for different devices, attachment locations and on larger/diverse cohorts.

OBT/HTO ratio in agricultural produce subject to routine atmospheric releases of tritium.

The mean expected value of the OBT/HTO ratio (i.e. generic ratio) is derived in this study on the joint basis of a long-term study conducted at Atomic Energy of Canada Limited (AECL)'s Chalk River Laboratories (CRL), model simulations targeted at filling gaps in a yet incomplete timeline of CRL measurements and a reference dataset comprised of numerous experiments reported in the literature. Cultivar variability and disparity in site-specific settings are covered by the reference dataset. Dynamical variability caused by meteorology has been a specific target of the long-term experimental campaign at CRL, where the former two types of variability were eliminated. The distribution of OBT/HTO ratios observed at CRL appears to be a fairly good match to the distribution of OBT/HTO ratios from the literature. This implies that dynamical variability appears important in both cases. Dynamics of atmospheric HTO at CRL is comprised of a sequence of episodes of atmospheric HTO uptake and re-emission of plant HTO. The OBT/HTO ratio appears sensitive to the proportion of the duration of these two episodes: the lesser the frequency (and duration) of plume arrivals, the higher the expected mean OBT/HTO ratio. With the plume arrival frequency defined by the typical wind rose, one would encounter a mean OBT/HTO ratio close to 2. It is important to note that this number is seen both in the reference dataset, and in the continuous timeline of HTO and OBT reconstructed from CRL observations by dynamical interpolation (modelling). Many datasets (including that of CRL) targeted at the OBT/HTO ratio are biased high compared to the suggested number. This could be explained by scarce measurements of the low OBT/HTO ratios in the short phase of uptake of atmospheric HTO by the plant.

Current understanding of organically bound tritium (OBT) in the environment.

It has become increasingly recognized that organically bound tritium (OBT) is the more significant tritium fraction with respect to understanding tritium behaviour in the environment. There are many different terms associated with OBT; such as total OBT, exchangeable OBT, non-exchangeable OBT, soluble OBT, insoluble OBT, tritiated organics, and buried tritium, etc. A simple classification is required to clarify understanding within the tritium research community. Unlike for tritiated water (HTO), the environmental quantification and behaviour of OBT are not well known. Tritiated water cannot bio-accumulate in the environment. However, it is not clear whether or not this is the case for OBT. Even though OBT can be detected in terrestrial biological materials, aquatic biological materials and soil samples, its behaviour is still in question. In order to evaluate the radiation dose from OBT accurately, further study will be required to understand OBT measurements and determine OBT fate in the environment. The relationship between OBT speciation and the OBT/HTO ratio in environmental samples will be useful in this regard, providing information on the previous tritium exposure conditions in the environment and the current tritium dynamics.

Field measurements of key parameters associated with nocturnal OBT formation in vegetables grown under Canadian conditions.

The objective of this study was to provide the parameter values required to model OBT formation in the edible parts of plants following a hypothetical accidental tritium release to the atmosphere at night. The parameters considered were leaf area index, stomatal resistance, photosynthesis rate, the photosynthetic production rate of starch, the nocturnal hydrolysis rate of starch, the fraction of starch produced daily by photosynthesis that appears in the fruits, and the mass of the fruit. Values of these parameters were obtained in the summer of 2002 for lettuce, radishes and tomatoes grown under typical Canadian environmental conditions. Based on the maximum observed photosynthetic rate and growth rate, the fraction of starch translocated to the fruit was calculated to be 17% for tomato fruit and 14% for radish root.

Methods and strategies for gene structure curation in WormBase.

The Caenorhabditis elegans genome sequence was published over a decade ago; this was the first published genome of a multi-cellular organism and now the WormBase project has had a decade of experience in curating this genome's sequence and gene structures. In one of its roles as a central repository for nematode biology, WormBase continues to refine the gene structure annotations using sequence similarity and other computational methods, as well as information from the literature- and community-submitted annotations. We describe the various methods of gene structure curation that have been tried by WormBase and the problems associated with each of them. We also describe the current strategy for gene structure curation, and introduce the WormBase 'curation tool', which integrates different data sources in order to identify new and correct gene structures. Database URL: http://www.wormbase.org/.

Prognostic value of hypoxia inducible factor 1α in esophageal squamous cell carcinoma.

Hypoxia inducible factor 1α (HIF 1α) plays a major role in the pleitropic response observed secondary to hypoxic conditions in tumors. Its expression in the tumor cells has been correlated to tumor aggressiveness and prognosis in squamous cell carcinoma (SCC) of the esophagus in Far Eastern population, but limited information is available on the prognostic role of HIF 1α in SCC of esophagus in European population. This information may help in choosing appropriate therapeutic strategies and possibly developing a monoclonal antibody with therapeutic potential targeting the HIF 1α. Tumor samples from 36 patients diagnosed with SCC of the esophagus were collected. Prepared tissue sections were stained with validated and specific monoclonal antibodies for HIF 1α and the expression was correlated with the disease pattern and survival. Out of 36 patients, 17 patients showed low and 19 high expression of HIF 1α. There was no difference in the disease-free and overall survival between these two groups (P > 0.05, log rank test). Regression analysis showed that HIF 1α was not an independent prognostic factor for survival (P > 0.05). HIF 1α did not show prognostic value in SCC of the esophagus in our study on European population, in agreement with previous studies. Novel strategies on the therapeutic manipulation of HIF 1α in cancer are to be explored further and may have a role to play in improving treatment outcome.

Oxidative stress-related proteins in a Conn's adenoma tissue. Relevance for aldosterone's prooxidative and proinflammatory activity.

BACKGROUND AND AIM: Angiotensin II (Ang II) induces oxidative stress (OxSt), which is essential for cardiovascular remodeling. Aldosterone also induces fibrosis and remodeling through direct effect on non-classical mineralocorticoid (MR) target tissues. However, studies on the role of aldosterone on OxSt and related factors in humans are lacking. MATERIALS AND METHODS: We assessed gene and protein expression of p22phox (RT-PCR and Western blot), NAD(P)H oxidase subunit essential for superoxide production and gene expression of transforming growth fator (TGF) beta, plasminogen activator inhibitor (PAI)-1, and heme oxygenase (HO)-1, effectors of OxSt (RT-PCR), in a Conn's adenoma, removed from a patient with primary hyperaldosteronism. Ang II type 1 (AT1R) and MR receptors expression were also evaluated (RT-PCR). The normal adrenal tissue adjacent to the adenoma was used as control. RESULTS: p22phox gene and protein expression were higher (31% and 53%, respectively) in the adrenal adenoma. TGFbeta, PAI-1, and HO-1 gene expression were also higher (25%, 129%, and 25%, respectively) in the adrenal adenoma while AT1R gene expression was similar (8%). The expression of MR in the adenoma was documented. CONCLUSIONS: This report demonstrates in a human model that the increased aldosterone production has effects on enzyme systems related to OxSt, enhancing the systemic fibrogenic effects of aldosterone excess through TGFbeta and PAI-1 expression which was previously demonstrated only indirectly in vitro and in animal models. The presence of MR expression in the adenoma may link the hormone with the adenoma growth. Therefore, the results of this study derived from a single case might represent an important working hypothesis for further research in a larger number of cases to clarify the role of aldosterone overproduction on OxSt and its clinical relevance.

Beta-carotene prevents ozone-induced proinflammatory markers in murine skin.

Beta-carotene has been thought to protect against oxidative stress generated by ultraviolet radiation and thus prevents skin cancer and skin aging (Biesalski and Obermueller-Jevic, 2001). However, nothing is known about its potential effects against other environmental sources of oxidative stress such as ozone (O3) in skin. Intake of oral beta-carotene supplements before exposure to sunlight (and thus inevitably also to (O3) has been recommended on a population-wide basis. However, although some studies have shown beta-carotene as providing skin protection as an antioxidant, other studies using skin cells in culture have shown that beta-carotene may have unexpected prooxidant properties (Obermüller-Jevic, et al., 2001). Given this, there is an ongoing debate regarding the protective or potentially harmful role(s) of beta-carotene in human skin. In this study, the effect of beta-carotene on ozone's effects on the skin of hairless mice was assessed. After feeding a diet supplemented with 0.5% beta-carotene for 1 month, mice were subjected to O3 exposure (0.8 ppm 6 h/day; 7 days) and the induction of proinflammatory markers such as tumor necrosis factor-alpha (TNFalpha), macrophage inflammatory protein 2 (MIP2), and inducible nitric oxide synthase (iNOS), and markers of oxidative stress, heme-oxygenase-1 (HO-1), were quantitated. The data showed that beta-carotene downregulated the induction of TNFalpha, MIP2, iNOS, and HO-1 in response to O3. We conclude that beta-carotene provides protection against O3-induced skin oxidative stress in vivo, which is consistent with a protective role for beta-carotene in the skin.

High angiotensin II state without cardiac remodeling (Bartter's and Gitelman's syndromes): are angiotensin II type 2 receptors involved?

BACKGROUND/AIMS: While Angiotensin II (Ang II) is a major factor in the development of cardiomyocyte hypertrophy and a pivotal role for Ang II signals via ERK1/2 has been identified, mechanism(s) responsible are still unclear. As Bartter's and Gitelman's syndrome patients (BS/GS) have increased Ang II, and yet normo/hypotension, hyporesponsiveness to pressors and blunted Ang II signaling via type 1 receptors (AT1R), this study assesses BS/GS's left ventricular (LV) mass and structure as well as Ang II induced ERK1/2 phosphorylation compared with essential hypertensive patients (EH) and normotensive healthy subjects (C) to gain insight into Ang II mediated processes. METHODS: Indices of cardiac hypertrophy were determined by M-mode, two-dimensional echo Doppler and ERK phosphorylation by Western blot. RESULTS: None of BS/GS exhibited LV remodelling; LV mass, LV end-diastolic volume and mass/volume ratio were unchanged vs C (60+/-14 g/m2 vs 64+/-12, 64+/-12 ml/m2 vs 60+/-8 and 0.95+/-0.2 vs 1.0+/-0.2, respectively) and reduced vs EH (119+/-15, p<0.001, 78+/-9, p<0.05 and 1.52+/-0.15, p<0.01). Despite BS/GS's higher plasma renin activity and aldosterone and unchanged level of AT1R, Ang II induced ERK1/2 phosphorylation was reduced vs both C and EH: 0.64 d.u.+/-0.08 vs 0.90+/-0.06 in C, p<0.006, and vs 1.45+/-0.07 in EH, p<0.001. CONCLUSION: The data point to a direct cardioremodeling role for Ang II and support a role of Ang II type 2 receptor (AT2R) signaling as involved in the lack of cardiovascular remodeling in BS/GS. However, further studies using more direct approaches to demonstrate the effects of AT2R signaling must be pursued.

Nitroxide radical TEMPO reduces ozone-induced chemokine IL-8 production in lung epithelial cells.

Exposure to high levels of ozone (O(3)) damages respiratory tract epithelial cells. This research evaluated the ability of TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl), a stable nitroxide free radical, to decrease O(3)-mediated injury to a respiratory tract-derived cell line (A549 cells) by monitoring in this cell system the interleukine-8 (IL-8) production. TEMPO reduced O(3)-induced IL-8 production in A549 cells, as evidenced by PCR analysis, Western blot and ELISA assays. This behaviour is explainable on the basis of the reactivity between TEMPO with O(3) and/or O(3)-derived free radicals in biological systems. The study provides evidence that TEMPO reacts with O(3) and/or its cytotoxic products and may provide protections against O(3)-induced biotoxicities.

International study on the validation of models for the environmental transfer of tritium and carbon-14.

The International Atomic Energy Agency (IAEA)'s Environmental Modelling for Radiation Safety (EMRAS) model evaluation programme includes a Tritium and Carbon-14 Working Group (TCWG), the goal of which is to test the performance of models for the environmental transfer. This paper describes work on two of the nine TCWG scenarios; one involved the prediction of time-dependent tritium concentrations in freshwater mussels subject to an abrupt change in ambient tritium levels and the second was concerned with the prediction of carbon-14 concentrations in rice grown in the vicinity of sources of continuous atmospheric releases.

Carbon-14 transfer into rice plants from a continuous atmospheric source: observations and model predictions.

Carbon-14 (14C) is one of the most important radionuclides from the perspective of dose estimation due to the nuclear fuel cycle. Ten years of monitoring data on 14C in airborne emissions, in atmospheric CO2 and in rice grain collected around the Tokai reprocessing plant (TRP) showed an insignificant radiological effect of the TRP-derived 14C on the public, but suggested a minor contribution of the TRP-derived 14C to atmospheric 14C concentrations, and an influence on 14C concentrations in rice grain at harvest. This paper also summarizes a modelling exercise (the so-called rice scenario of the IAEA's EMRAS program) in which 14C concentrations in air and rice predicted with various models using information on 14C discharge rates, meteorological conditions and so on were compared with observed concentrations. The modelling results showed that simple Gaussian plume models with different assumptions predict monthly averaged 14C concentrations in air well, even for near-field receptors, and also that specific activity and dynamic models were equally good for the prediction of inter-annual changes in 14C concentrations in rice grain. The scenario, however, offered little opportunity for comparing the predictive capabilities of these two types of models because the scenario involved a near-chronic release to the atmosphere. A scenario based on an episodic release and short-term, time-dependent observations is needed to establish the overall confidence in the predictions of environmental 14C models.