1,148 research outputs found
Aflatoxin B(1) and Fumonisin B(1) Co-Contamination: Interactive Effects, Possible Mechanisms of Toxicity, and Decontamination Procedures.
The current study evaluated interactions between the mycotoxins aflatoxin B\sb1 (AFB\sb1) and fumonisin B\sb1 (FB\sb1) in pure systems as well as in corn. During storage at 25\sp\circC with high moisture (ca. 50%), corn contaminated with Aspergillus flavus (L13) and/or Fusarium moniliforme (A00102) presented different aflatoxin and fumonisin levels. Toxin production/degradation varied over storage time (0-45 days). Evaluation of the mutagenicity of unifungal or bifungal corn extracts with the Salmonella/microsomal assay (tester strains TA-100 and TA-98) with metabolic activation (S9) showed positive mutagenic responses. Different ratios of pure AFB\sb1/FB\sb1 produced divergent mutagenic responses (tester strains TA-100 and TA-98) with S9. The mutagenicity of 10\sp3 ng AFB\sb1/plate was reduced by addition of 1 to 10\sp2 ng FB\sb1/plate. Higher FB\sb1 concentrations (10\sp3 to 10\sp5 ng/plate) caused an opposite effect. The mutagenic potential of 2-aminofluorene (2-AF) was also affected by FB\sb1. This suggested that FB\sb1 affects the enzyme systems responsible for activating AFB\sb1 and 2-AF. Analysis by liquid chromatography of AFB\sb1/AFB\sb1-metabolites after reaction with FB\sb1 and S9 showed decreased recovery when 10\sp3 ng AFB\sb1 were exposed to 1 to 10\sp2 ng FB\sb1, but at higher FB\sb1 levels (10\sp3 to 10\sp5 ng), recovery was increased. Thin layer chromatography analysis of these samples suggested that unidentified AFB\sb1-metabolites derivatized with trifluoroacetic acid were indirectly detected as AFB\sb1.. FB\sb1 (1 to 10\sp5 ng/plate) inhibited gap-junction intercellular communication of Clone-9 rat liver cells. This could be a possible mechanism by which FB\sb1 acts as a non-genotoxic carcinogen. Addition of 1 to 10\sp3 ng AFB\sb1 to 10\sp5 ng FB\sb1 did not change the effect of FB\sb1. An increase in the uptake of neutral red by Clone-9 rat liver cells exposed to AFB\sb1/FB\sb1 implied that peroxisome proliferation and oxidative metabolism may be involved in AFB\sb1/FB\sb1 interactions. H\sb2O\sb2 (3%) and NaHCO\sb3 (2%) were effective in decontaminating/detoxifying aflatoxin-fumonisin naturally co-contaminated corn without generating mutagenic by-products. This study showed preliminary evidence that simultaneous exposure to AFB\sb1/FB\sb1 can give different toxicological responses than single exposure to either of these compounds. More research is needed to better assess the toxicological impact of AFB\sb1/FB\sb1 co-contamination and to develop possible control strategies
Probing the accretion-ejection connection with VLTI/AMBER: High spectral resolution observations of the Herbig Ae star HD163296
Accretion and ejection are tightly connected and represent the fundamental
mechanisms regulating star formation. However, the exact physical processes
involved are not yet fully understood. We present high angular and spectral
resolution observations of the Br Gamma emitting region in the Herbig Ae star
HD163296 (MWC275) in order to probe the origin of this line and constrain the
physical processes taking place at sub-AU scales in the circumstellar region.
By means of VLTI-AMBER observations at high spectral resolution (R~12000), we
studied interferometric visibilities, wavelength-differential phases, and
closure phases across the Br Gamma line of HD163296. To constrain the physical
origin of the Br Gamma line in Herbig Ae stars, all the interferometric
observables were compared with the predictions of a line radiative transfer
disc wind model. The measured visibilities clearly increase within the Br Gamma
line, indicating that the Br Gamma emitting region is more compact than the
continuum. By fitting a geometric Gaussian model to the continuum-corrected Br
Gamma visibilities, we derived a compact radius of the Br Gamma emitting region
of ~0.07+/-0.02AU (Gaussian half width at half maximum; or a ring-fit radius of
~0.08+/-0.02AU). To interpret the observations, we developed a
magneto-centrifugally driven disc wind model. Our best disc wind model is able
to reproduce, within the errors, all the interferometric observables and it
predicts a launching region with an outer radius of ~0.04AU. However, the
intensity distribution of the entire disc wind emitting region extends up to
~0.16AU. Our observations, along with a detailed modelling of the Br Gamma
emitting region, suggest that most of the Br Gamma emission in HD163296
originates from a disc wind with a launching region that is over five times
more compact than previous estimates of the continuum dust rim radius.Comment: Accepted for publication in A&
Analysis of matched geographical areas to study potential links between environmental exposure to oil refineries and non-Hodgkin lymphoma mortality in Spain
BACKGROUND: Emissions from refineries include a wide range of substances, such as chrome, lead, nickel, zinc, arsenic, cadmium, benzene, dioxins and furans, all of which are recognized by the International Agency for Research on Cancer (IARC) as carcinogens. Various studies have shown an association between non-Hodgkin lymphoma (NHL) and residence in the vicinity of industrial areas; however, evidence of specific association between refineries and residence in the vicinity has been suggested but not yet established. The aim of this study is to investigate potential links between environmental exposure to emissions from refineries and non-Hodgkin lymphoma mortality in Spain. The spatial distribution of NHL in Spain has an unusual pattern with regions some showing higher risk than others. METHODS: We designed an analysis of matched geographical areas to examine non-Hodgkin lymphoma mortality in the vicinity of the 10 refineries sited in Spain over the period 1997-2006. Population exposure to refineries was estimated on the basis of distance from town of residence to the facility in a 10 km buffer. We defined 10 km radius areas to perform the matching, accounting for population density, level of industrialization and socio-demographic factors of the area using principal components analysis. For the matched towns we evaluated the risk of NHL mortality associated with residence in the vicinity of the refineries and with different regions using mixed Poisson models. Then we study the residuals to assess a possible risk trend with distance. RESULTS: Relative risks (RRs) associated with exposure showed similar values for women and for men, 1.09 (0.97-1.24) and 1.12 (0.99-1.27). RRs for two regions were statistically significant: Canary Islands showed an excess of risk of 1.35 (1.05-1.72) for women and 1.50 (1.18-1.92) for men, whilst Galicia showed an excess of risk of 1.35 (1.04-1.75) for men, but not significant excess for women. CONCLUSIONS: The results suggest a possible increased risk of NHL mortality among populations residing in the vicinity of refineries; however, a potential distance trend has not been shown. Regional effects in the Canary Islands and Galicia are significantly greater than the regional average
Investigating episodic accretion in a very low-mass young stellar object
Very low-mass Class I protostars have been investigated very little thus far.
Variability of these young stellar objects (YSOs) and whether or not they are
capable of strong episodic accretion is also left relatively unstudied. We
investigate accretion variability in IRS54, a Class I very low-mass protostar
with a mass of M ~ 0.1 - 0.2 M. We obtained spectroscopic
and photometric data with VLT/ISAAC and VLT/SINFONI in the near-infrared (,
, and bands) across four epochs (2005, 2010, 2013, and 2014). We used
accretion-tracing lines (Pa and Br) and outflow-tracing lines
(H and [FeII] to examine physical properties and kinematics of the object.
A large increase in luminosity was found between the 2005 and 2013 epochs of
more than 1 magnitude in the band, followed in 2014 by a steep decrease.
Consistently, the mass accretion rate () rose by an order of
magnitude from ~ 10 M yr to ~ M
yr between the two early epochs. The visual extinction () has also
increased from ~ 15 mag in 2005 to ~ 24 mag in 2013. This rise in in
tandem with the increase in is explained by the lifting up of a
large amount of dust from the disc of IRS54, following the augmented accretion
and ejection activity in the YSO, which intersects our line of sight due to the
almost edge-on geometry of the disc. Because of the strength and timescales
involved in this dramatic increase, this event is believed to have been an
accretion burst possibly similar to bursts of EXor-type objects. IRS54 is the
lowest mass Class I source observed to have an accretion burst of this type,
and therefore potentially one of the lowest mass EXor-type objects known so
far
Validation of the geographic position of EPER-Spain industries
BACKGROUND: The European Pollutant Emission Register in Spain (EPER-Spain) is a public inventory of pollutant industries created by decision of the European Union. The location of these industries is geocoded and the first published data correspond to 2001. Publication of these data will allow for quantification of the effect of proximity to one or more such plant on cancer and all-cause mortality observed in nearby towns. However, as errors have been detected in the geocoding of many of the pollutant foci shown in the EPER, it was decided that a validation study should be conducted into the accuracy of these co-ordinates. EPER-Spain geographic co-ordinates were drawn from the European Environment Agency (EEA) server and the Spanish Ministry of the Environment (MOE). The Farm Plot Geographic Information System (Sistema de Información Geográfica de Parcelas Agrícolas) (SIGPAC) enables orthophotos (digitalized aerial images) of any territorial point across Spain to be obtained. Through a search of co-ordinates in the SIGPAC, all the industrial foci (except farms) were located. The quality criteria used to ascertain possible errors in industrial location were high, medium and low quality, where industries were situated at a distance of less than 500 metres, more than 500 metres but less than 1 kilometre, and more than 1 kilometre from their real locations, respectively. RESULTS: Insofar as initial registry quality was concerned, 84% of industrial complexes were inaccurately positioned (low quality) according to EEA data versus 60% for Spanish MOE data. The distribution of the distances between the original and corrected co-ordinates for each of the industries on the registry revealed that the median error was 2.55 kilometres for Spain overall (according to EEA data). The Autonomous Regions that displayed most errors in industrial geocoding were Murcia, Canary Islands, Andalusia and Madrid. Correct co-ordinates were successfully allocated to 100% of EPER-Spain industries. CONCLUSION: Knowing the exact location of pollutant foci is vital to obtain reliable and valid conclusions in any study where distance to the focus is a decisive factor, as in the case of the consequences of industrial pollution on the health of neighbouring populations.This study was funded by grant FIS 040041 from the Health Research Fund (Fondo de Investigación Sanitaria)S
Childhood leukemia and residential proximity to industrial and urban sites
BACKGROUND: Few risk factors for the childhood leukemia are well established. While a small fraction of cases of childhood leukemia might be partially attributable to some diseases or ionizing radiation exposure, the role of industrial and urban pollution also needs to be assessed. OBJECTIVES: To ascertain the possible effect of residential proximity to both industrial and urban areas on childhood leukemia, taking into account industrial groups and toxic substances released. METHODS: We conducted a population-based case-control study of childhood leukemia in Spain, covering 638 incident cases gathered from the Spanish Registry of Childhood Tumors and for those Autonomous Regions with 100% coverage (period 1990-2011), and 13,188 controls, individually matched by year of birth, sex, and autonomous region of residence. Distances were computed from the respective subject's residences to the 1068 industries and the 157 urban areas with ≥10,000 inhabitants, located in the study area. Using logistic regression, odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance to industrial and urban pollution sources were calculated, with adjustment for matching variables. RESULTS: Excess risk of childhood leukemia was observed for children living near (≤2.5 km) industries (OR=1.31; 95%CI=1.03-1.67) - particularly glass and mineral fibers (OR=2.42; 95%CI=1.49-3.92), surface treatment using organic solvents (OR=1.87; 95%CI=1.24-2.83), galvanization (OR=1.86; 95%CI=1.07-3.21), production and processing of metals (OR=1.69; 95%CI=1.22-2.34), and surface treatment of metals (OR=1.62; 95%CI=1.22-2.15) - , and urban areas (OR=1.36; 95%CI=1.02-1.80). CONCLUSIONS: Our study furnishes some evidence that living in the proximity of industrial and urban sites may be a risk factor for childhood leukemia.This study was funded by Spain’s Health Research Fund (Fondode Investigación Sanitaria–FIS 12/01416 and FIS CP11/00112).S
Clinical Effects of Liraglutide in a Real-World Setting in Spain: eDiabetes-Monitor SEEN Diabetes Mellitus Working Group Study
Introduction: A limitation with randomized controlled trials is that, while they provide unbiased evidence of the efficacy of interventions, they do so under unreal conditions and in a very limited and highly selected patient population. Our aim was to provide data about the effectiveness of liraglutide treatment in a real-world and
clinical practice setting.
Methods: In a retrospective and observational study, data from 753 patients with type 2 diabetes were recorded through an online tool (eDiabetes-Monitor).
Results: Mean baseline glycated hemoglobin (HbA1c) was 8.4 ± 1.4% and mean body mass index (BMI) was 38.6 ± 5.4 kg/m2. After 3–6 months of treatment with liraglutide, we observed a change in HbA1c of -1.1 ± 1.2%, -4.6 ± 5.3 kg in weight and -1.7 ± 2.0 kg/m
Oesophageal cancer mortality in Spain: a spatial analysis
BACKGROUND: Oesophageal carcinoma is one of the most common cancers worldwide. Its incidence and mortality rates show a wide geographical variation at a world and regional level. Geographic mapping of age-standardized, cause-specific death rates at a municipal level could be a helpful and powerful tool for providing clues leading to a better understanding of its aetiology. METHODS: This study sought to describe the geographic distribution of oesophageal cancer mortality for Spain's 8077 towns, using the autoregressive spatial model proposed by Besag, York and Mollié. Maps were plotted, depicting standardised mortality ratios, smoothed relative risk (RR) estimates, and the spatial pattern of the posterior probability of RR being greater than 1. RESULTS: Important differences associated with area of residence were observed in risk of dying from oesophageal cancer in Spain during the study period (1989-1998). Among men, excess risk appeared across the north of the country, along a band spanning the length of the Cantabrian coastline, Navarre, the north of Castile & León and the north-west of La Rioja. Excess risk was likewise observed in the provinces of Cadiz and part of Seville in Andalusia, the islands of Tenerife and Gran Canaria, and some towns in the Barcelona and Gerona areas. Among women, there was a noteworthy absence of risk along the mid-section of the Cantabrian seaboard, and increases in mortality, not observed for men, in the west of Extremadura and south-east of Andalusia. CONCLUSION: These major gender- and area-related geographical differences in risk would seem to reflect differences in the prevalence of some well-established and modifiable risk factors, including smoking, alcohol consumption, obesity and diet. In addition, excess risks were in evidence for both sexes in some areas, possibly suggesting the implication of certain local environmental or socio-cultural factors. From a public health standpoint, small-area studies could be very useful for identifying locations where epidemiological research and intervention measures ought to receive priority, given the potential for reducing risk in certain places.This study was funded by Grant No. EPY-1176/02 from the Carlos III Institute of Health (ISCIII) and RCESP FIS-C03/09 (Spanish Network for Cooperative Research in Epidemiology and Public Health)S
Factors Contributing to the Utilization of Adult Mental Health Services in Children and Adolescents Diagnosed with Hyperkinetic Disorder
Objectives. To examine whether age of First diagnosis, gender, psychiatric comorbidity, and treatment modalities (pharmacotherapy or psychotherapy) at Child and Adolescent Mental Health Services (CAMHS) moderate the risk of Adult Mental Health Services (AMHS) utilization in patients diagnosed with hyperkinetic disorder at CAMHS. Methods. Data were derived from the Madrid Psychiatric Cumulative Register Study. The target population comprised 32,183 patients who had 3 or more visits at CAMHS. Kaplan-Meier curves were used to assess survival data. A series of logistic regression analyses were performed to study the role of age of diagnosis, gender, psychiatric comorbidity, and treatment modalities. Results. 7.1% of patients presented with hyperkinetic disorder at CAMHS. Compared to preschool children, children and adolescents first diagnosed with hyperkinetic disorder at CAMHS were more likely to use AMHS. Female gender and comorbidity with affective disorders, schizophrenia, schizotypal and delusional disorders increased the risk of use of AMHS. Pharmacological or combined treatment of hyperkinetic disorder diagnosed at CAMHS was associated with increased risk of use at AMHS. Conclusions. Older age of first diagnosis, female gender, psychiatric comorbidity, and pharmacological treatment at CAMHS are markers of risk for the transition from CAMHS to AMHS in patients with hyperkinetic disorder diagnosed at CAMHS
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