738 research outputs found
Recommended from our members
Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils
Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability
Insulin release: synchronizing beta cells in the pancreas
The secretion of insulin from the pancreas relies on both gap junctions and subpopulations of beta cells with specific intrinsic properties
Hepatic fatty acid and glucose handling in metabolic disease: potential impact on cardiovascular disease risk
The prevalence of metabolic diseases, including type 2 diabetes mellitus (T2DM) and metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing. Although invariably associated with obesity, the importance of fat deposition in non-adipose tissue organs has yet to be fully explored. Pathological ectopic fat deposition within the liver (known as (MASLD)) has been suggested to underlie the development of T2DM and is now emerging as an independent risk factor for cardiovascular disease (CVD). The process of hepatic de novo lipogenesis (DNL), that is the synthesis of fatty acids from non-lipid precursors (e.g. glucose), has received much attention as it sits at the intersect of hepatic glucose and fatty acid handling. An upregulation of the DNL pathway has been suggested to be central in the development of metabolic diseases (including MASLD, insulin resistance, and T2DM). Here we review the evidence to determine if hepatic DNL may play a role in the development of MASLD and T2DM and therefore underlie an increased risk of CVD
Guidance for the identification of bony lesions related to smallpox
ObjectiveThis research aimed to address the underrepresentation of smallpox (osteomyelitis variolosa) in palaeopathology, providing a synthesis of published literature and presenting guidance for the identification of osteomyelitis variolosa in non-adult and adult skeletal remains.Materials and methodsLiterature regarding smallpox and published reports of individuals with osteomyelitis variolosa were synthesised and critiqued to produce clear diagnostic criteria for the identification of smallpox osteologically.ResultsAssociated osteological changes begin in non-adults, where skeletal morphology is rapidly changing. Characteristic lesions associated with non-adult osteomyelitis variolosa include inflammation and destructive remodelling of long-bone joints and metaphyses. Where childhood infection was survived, residual osteomyelitis variolosa lesions should also be visible in adults in the osteoarchaeological record.ConclusionsDespite long-term clinical recognition, only limited osteological and archaeological evidence of osteomyelitis variolosa has yet emerged. With improved diagnostic criteria, osteomyelitis variolosa may be more frequently identified.SignificanceThis is the first synthesis of osteomyelitis variolosa encompassing both clinical and palaeopathological literature, providing detailed guidance for the identification of osteomyelitis variolosa in skeletal remains. It will lead to the increased identification of smallpox osteologically.LimitationsDifferential diagnoses should always be considered. The archaeological longevity of smallpox, and the potential for archaeological VARV to cause clinically recognised smallpox, is currently unknown. Characteristic bone changes in the archaeological record may be other, extinct human-infecting-orthopoxviruses.Suggestions for further researchFurther consideration of the implications of age of smallpox contraction on bony pathology: whether epiphyses are affected differently due to state of fusion. Reassessment of individuals previously identified with smallpox-consistent lesions, but otherwise diagnosed
Architecture of androgen receptor pathways amplifying glucagon-like peptide-1 insulinotropic action in male pancreatic β cells
Male mice lacking the androgen receptor (AR) in pancreatic β cells exhibit blunted glucose-stimulated insulin secretion (GSIS), leading to hyperglycemia. Testosterone activates an extranuclear AR in β cells to amplify glucagon-like peptide-1 (GLP-1) insulinotropic action. Here, we examined the architecture of AR targets that regulate GLP-1 insulinotropic action in male β cells. Testosterone cooperates with GLP-1 to enhance cAMP production at the plasma membrane and endosomes via: (1) increased mitochondrial production of CO2, activating the HCO3−-sensitive soluble adenylate cyclase; and (2) increased Gαs recruitment to GLP-1 receptor and AR complexes, activating transmembrane adenylate cyclase. Additionally, testosterone enhances GSIS in human islets via a focal adhesion kinase/SRC/phosphatidylinositol 3-kinase/mammalian target of rapamycin complex 2 actin remodeling cascade. We describe the testosterone-stimulated AR interactome, transcriptome, proteome, and metabolome that contribute to these effects. This study identifies AR genomic and non-genomic actions that enhance GLP-1-stimulated insulin exocytosis in male β cells
Recommended from our members
Relative proportions of polycyclic aromatic hydrocarbons differ between accumulation bioassays and chemical methods to predict bioavailability
Chemical methods to predict the bioavailable fraction of organic contaminants are usually validated in the literature by comparison with established bioassays. A soil spiked with polycyclic aromatic hydrocarbons (PAHs) was aged over six months and subjected to butanol, cyclodextrin and tenax extractions as well as an exhaustive extraction to determine total PAH concentrations at several time points. Earthworm (Eisenia fetida) and rye grass root (Lolium multiflorum) accumulation bioassays were conducted in parallel. Butanol extractions gave the best relationship with earthworm accumulation (r2 ≤ 0.54, p ≤ 0.01); cyclodextrin, butanol and acetone–hexane extractions all gave good predictions of accumulation in rye grass roots (r2 ≤ 0.86, p ≤ 0.01). However, the profile of the PAHs extracted by the different chemical methods was significantly different (p < 0.01) to that accumulated in the organisms. Biota accumulated a higher proportion of the heavier 4-ringed PAHs. It is concluded that bioaccumulation is a complex process that cannot be predicted by measuring the bioavailable fraction alone.
The ability of chemical methods to predict PAH accumulation in Eisenia fetida and Lolium multiflorum was hindered by the varied metabolic fate of the different PAHs within the organisms
From the Wieser report to Team Europe: explaining the ‘battle of the banks’ in development finance
The European Union (EU) and its member states are the world’s largest development donor, but the European financial architecture for development suffers from well-documented problems of fragmentation. EU member states’ decision to convene the Wieser Group in April 2019 raised expectations over rationalising the roles of the European Investment Bank (EIB) and the European Bank for Reconstruction and Development (EBRD). However, the Council of the EU showed little enthusiasm for the group’s call to create a single entity for external development finance. Twelve months later, member states endorsed Team Europe, an alternative approach which mobilises the resources of the EIB, the EBRD, the European Commission and national development finance institutions in support of shared development goals. This article seeks to explain why the Council ultimately preferred Team Europe’s coordinated approach to the Wieser Report’s centralised vision of a European Climate and Sustainable Development Bank. In keeping with new intergovernmentalism, we find that member states’ willingness to cooperate but reluctance to delegate, and the aim of EU institutions to protect their turf, favoured Team Europe. We see few reasons to expect radical changes in this domain despite continued doubts over the effectiveness and coherence of European development finance
- …