359 research outputs found
Assessing the exposure risk and impacts of pharmaceuticals in the environment on individuals and ecosystems.
The use of human and veterinary pharmaceuticals is increasing. Over the past decade, there has been a proliferation of research into potential environmental impacts of pharmaceuticals in the environment. A Royal Society-supported seminar brought together experts from diverse scientific fields to discuss the risks posed by pharmaceuticals to wildlife. Recent analytical advances have revealed that pharmaceuticals are entering habitats via water, sewage, manure and animal carcases, and dispersing through food chains. Pharmaceuticals are designed to alter physiology at low doses and so can be particularly potent contaminants. The near extinction of Asian vultures following exposure to diclofenac is the key example where exposure to a pharmaceutical caused a population-level impact on non-target wildlife. However, more subtle changes to behaviour and physiology are rarely studied and poorly understood. Grand challenges for the future include developing more realistic exposure assessments for wildlife, assessing the impacts of mixtures of pharmaceuticals in combination with other environmental stressors and estimating the risks from pharmaceutical manufacturing and usage in developing countries. We concluded that an integration of diverse approaches is required to predict 'unexpected' risks; specifically, ecologically relevant, often long-term and non-lethal, consequences of pharmaceuticals in the environment for wildlife and ecosystems
Transcription networks responsible for early regulation of Salmonella_induced inflammation in the jejunum of pigs
Background The aim of this study was to identify transcription factors/regulators that play a crucial role in steering the (innate) immune response shortly (within a few hours) after the first contact of the intestinal mucosa with an inflammatory mediator, and to test whether the processes regulated by these factors/regulators can be modulated by chemical substances of natural origin. Methods We experimentally induced inflammation by perfusion of surgically applied jejunal loops with Salmonella enterica subspecies enterica serovar Typhimurium DT104 in three pigs. Segments of mock and Salmonella treated loops were dissected after 2, 4 and 8¿hours of perfusion. IL8 and IL1-beta mRNA expression levels were measured in mucosal scrapings of all segments. Furthermore, intra-animal microarray comparisons (isogenic) between Salmonella and mock treated segments after 8¿hours, and inter-animal comparisons between similar Salmonella-treated loops of each pig at 2 and 4¿hours, were performed. Results IL-1beta and IL8 mRNA levels, and intra-animal microarray comparisons at 8¿hours between Salmonella and mock treated segments showed that the response-time and type of response to Salmonella was different in all three pigs. This plasticity allowed us to extract a comprehensive set of differentially expressed genes from inter-animal comparisons at 2 and 4¿hours. Pathway analysis indicated that many of these genes play a role in induction and/or tempering the inflammatory response in the intestine. Among them a set of transcription factors/regulators known to be involved in regulation of inflammation, but also factors/regulators for which involvement was not expected. Nine out of twenty compounds of natural origin, which according to literature had the potential to modulate the activity of these factors/regulators, were able to stimulate or inhibit a Salmonella-induced mRNA response of inflammatory-reporter genes IL8 and/or nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha in cultured intestinal porcine epithelial cells. Conclusions We describe a set of transcription factors/regulators possibly involved in regulation of “very early” immune mechanism which determines the inflammatory status of the intestine later on. In addition, we show that these mechanisms may be modulated by chemical substances of natural origin. Keywords: Transcription regulation; Salmonella-induced inflammation; Pig intestin
Blockade of vascular ATP-sensitive potassium channels reduces the vasodilator response to ischaemia in humans
Kinesin-4 KIF21B limits microtubule growth to allow rapid centrosome polarization in T cells
When a T cell and an antigen-presenting cell form an immunological synapse, rapid dynein-driven translocation of the centrosome towards the contact site leads to reorganization of microtubules and associated organelles. Currently, little is known about how the regulation of microtubule dynamics contributes to this process. Here, we show that the knockout of KIF21B, a kinesin-4 linked to autoimmune disorders, causes microtubule overgrowth and perturbs centrosome translocation. KIF21B restricts microtubule length by inducing microtubule pausing typically followed by catastrophe. Catastrophe induction with vinblastine prevented microtubule overgrowth and was sufficient to rescue centrosome polarization in KIF21B-knockout cells. Biophysical simulations showed that a relatively small number of KIF21B molecules can restrict microtubule length and promote an imbalance of dynein-mediated pulling forces that allows the centrosome to translocate past the nucleus. We conclude that proper control of microtubule length is important for allowing rapid remodeling of the cytoskeleton and efficient T cell polarization
Comparison of a Flow Assay for Brucellosis Antibodies with the Reference cELISA Test in West African Bos indicus
Brucellosis is considered by the Food and Agricultural Organisation and the World Health Organisation as one of the most widespread zoonoses in the world. It is a major veterinary public health challenge as animals are almost exclusively the source of infection for people. It is often undiagnosed in both human patients and the animal sources and it is widely acknowledged that the epidemiology of brucellosis in humans and animals is poorly understood, particularly in sub-Saharan Africa. It is therefore important to develop better diagnostic tools in order to improve our understanding of the epidemiology and also for use in the field for disease control and eradication. As with any new diagnostic test, it is essential that it is validated in as many populations as possible in order to characterise its performance and improve the interpretation of its results. This paper describes a comparison between a new lateral flow assasy (LFA) for bovine brucellosis and the widely used cELISA in a no gold standard analysis to estimate test performance in this West African cattle population. A Bayesian formulation of the Hui-Walter latent class model incorporated previous studies' data on sensitivity and specificity of the cELISA. The results indicate that the new LFA is very sensitive (∼87%) and highly specific (∼97%). The analysis also suggests that the current cut-off of the cELSIA may not be optimal for this cattle population but alternative cut-offs did not significantly change the estimates of the LFA. This study demonstrates the potential usefulness of this simple to use test in field based surveillance and control which could be easily adopted for use in developing countries with only basic laboratory facilities
Prevalence and consequences of patient safety incidents in general practice in the Netherlands: a retrospective medical record review study
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97252.pdf (publisher's version ) (Open Access)BACKGROUND: Patient safety can be at stake in both hospital and general practice settings. While severe patient safety incidents have been described, quantitative studies in large samples of patients in general practice are rare. This study aimed to assess patient safety in general practice, and to show areas where potential improvements could be implemented. METHODS: We conducted a retrospective review of patient records in Dutch general practice. A random sample of 1,000 patients from 20 general practices was obtained. The number of patient safety incidents that occurred in a one-year period, their perceived underlying causes, and impact on patients' health were recorded. RESULTS: We identified 211 patient safety incidents across a period of one year (95% CI: 185 until 241). A variety of types of incidents, perceived causes and consequences were found. A total of 58 patient safety incidents affected patients; seven were associated with hospital admission; none resulted in permanent disability or death. CONCLUSIONS: Although this large audit of medical records in general practices identified many patient safety incidents, only a few had a major impact on patients' health. Improving patient safety in this low-risk environment poses specific challenges, given the high numbers of patients and contacts in general practice
Radioactive Holmium Acetylacetonate Microspheres for Interstitial Microbrachytherapy: An In Vitro and In Vivo Stability Study
Purpose The clinical application of holmium acetylacetonate microspheres (HoAcAcMS) for the intratumoral radionuclide treatment of solid malignancies requires a thorough understanding of their stability. Therefore, an in vitro and an in vivo stability study with HoAcAcMS was conducted. Methods HoAcAcMS, before and after neutron irradiation, were incubated in a phosphate buffer at 37°C for 6 months. The in vitro release of holmium in this buffer after 6 months was 0.5%. Elemental analysis, scanning electron microscopy, infrared spectroscopy and time of flight secondary ion mass spectrometry were performed on the HoAcAcMS. Results After 4 days in buffer the acetylacetonate ligands were replaced by phosphate, without altering the particle size and surface morphology. HoAcAcMS before and after neutron irradiation were administered intratumorally in VX2 tumor-bearing rabbits. No holmium was detected in the faeces, urine, femur and blood. Histological examination of the tumor revealed clusters of intact microspheres amidst necrotic tissue after 30 days. Conclusion HoAcAcMS are stable both in vitro and in vivo and are suitable for intratumoral radionuclide treatment.Radiation, Radionuclides and ReactorsApplied Science
Expression of Multiple Resistance Genes Enhances Tolerance to Environmental Stressors in Transgenic Poplar (Populus × euramericana ‘Guariento’)
Commercial and non-commercial plants face a variety of environmental stressors that often cannot be controlled. In this study, transgenic hybrid poplar (Populus × euramericana ‘Guariento’) harboring five effector genes (vgb, SacB, JERF36, BtCry3A and OC-I) were subjected to drought, salinity, waterlogging and insect stressors in greenhouse or laboratory conditions. Field trials were also conducted to investigate long-term effects of transgenic trees on insects and salt tolerance in the transformants. In greenhouse studies, two transgenic lines D5-20 and D5-21 showed improved growth, as evidenced by greater height and basal diameter increments and total biomass relative to the control plants after drought or salt stress treatments. The improved tolerance to drought and salt was primarily attributed to greater instantaneous water use efficiency (WUEi) in the transgenic trees. The chlorophyll concentrations tended to be higher in the transgenic lines under drought or saline conditions. Transformed trees in drought conditions accumulated more fructan and proline and had increased Fv/Fm ratios (maximum quantum yield of photosystem II) under waterlogging stress. Insect-feeding assays in the laboratory revealed a higher total mortality rate and lower exuviation index of leaf beetle [Plagiodera versicolora (Laicharting)] larvae fed with D5-21 leaves, suggesting enhanced insect resistance in the transgenic poplar. In field trials, the dominance of targeted insects on 2-year-old D5-21 transgenic trees was substantially lower than that of the controls, indicating enhanced resistance to Coleoptera. The average height and DBH (diameter at breast height) of 2.5-year-old transgenic trees growing in naturally saline soil were 3.80% and 4.12% greater than those of the control trees, but these increases were not significant. These results suggested that multiple stress-resistance properties in important crop tree species could be simultaneously improved, although additional research is needed to fully understand the relationships between the altered phenotypes and the function of each transgene in multigene transformants
Identifying water stress-response mechanisms in citrus by in silico transcriptome analysis
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