332 research outputs found
DO SPORTFISH CONSUMPTION ADVISORIES AFFECT RESERVOIR ANGLERS' SITE CHOICE?
Increasing numbers of freshwater ecosystems have had sportfish consumption advisories posted in recent years. Advisories are sometimes issued in lieu of environmental remediation if they are considered more cost-effective than "cleaning up" the resource, but this approach assumes that anglers adjust behavior in response to the warning. Previous studies, however, suggest that compliance with advisories can be quite low. In contrast, this study measures a statistically significant response by reservoir anglers to consumption advisories. In particular, anglers are less likely to choose to visit a reservoir with an advisory than a similar reservoir without an advisory. Furthermore, the economic losses due to advisories are quantified for anglers in two regions of Tennessee.Resource /Energy Economics and Policy,
Functional Maturation of Induced Pluripotent Stem Cell Hepatocytes in Extracellular Matrix-A Comparative Analysis of Bioartificial Liver Microenvironments
Induced pluripotent stem cells (iPSCs) are new diagnostic and potentially therapeutic tools to model disease and assess the toxicity of pharmaceutical medications. A common limitation of cell lineages derived from iPSCs is a blunted phenotype compared with fully developed, endogenous cells. We examined the influence of novel three-dimensional bioartificial microenvironments on function and maturation of hepatocyte-like cells differentiated from iPSCs and grown within an acellular, liver-derived extracellular matrix (ECM) scaffold. In parallel, we also compared a bioplotted poly-L -lactic acid (PLLA) scaffold that allows for cell growth in three dimensions and formation of cell-cell contacts but is infused with type I collagen (PLLA-collagen scaffold) alone as a "deconstructed" control scaffold with narrowed biological diversity. iPSC-derived hepatocytes cultured within both scaffolds remained viable, became polarized, and formed bile canaliculi-like structures; however, cells grown within ECM scaffolds had significantly higher P450 (CYP2C9, CYP3A4, CYP1A2) mRNA levels and metabolic enzyme activity compared with iPSC hepatocytes grown in either bioplotted PLLA collagen or Matrigel sandwich control culture. Additionally, the rate of albumin synthesis approached the level of primary cryopreserved hepatocytes with lower transcription of fetal-specific genes, alpha-fetoprotein and CYP3A7, compared with either PLLA-collagen scaffolds or sandwich culture. These studies show that two acellular, three-dimensional culture systems increase the function of iPSC-derived hepatocytes. However, scaffolds derived from ECM alone induced further hepatocyte maturation compared with bioplotted PLLA-collagen scaffolds. This effect is likely mediated by the complex composition of ECM scaffolds in contrast to bioplotted scaffolds, suggesting their utility for in vitro hepatocyte assays or drug discovery.
SIGNIFICANCE Through the use of novel technology to develop three-dimensional (3D) scaffolds, the present study demonstrated that hepatocyte-like cells derived via induced pluripotent stem cell (iPSC) technology mature on 3D extracellular matrix scaffolds as a result of 3D matrix structure and scaffold biology. The result is an improved hepatic phenotype with increased synthetic and catalytic potency, an improvement on the blunted phenotype of iPSC-derived hepatocytes, a critical limitation of iPSC technology. These findings provide insight into the influence of 3D microenvironments on the viability, proliferation, and function of iPSC hepatocytes to yield a more mature population of cells for cell toxicity studies and disease modeling
Hematopoietic or osteoclast-specific deletion of Syk leads to increased bone mass in experimental mice
<p>Syk is a non-receptor tyrosine kinase critically involved in signaling by various immunoreceptors including B-cell-receptors and activating Fc-receptors. We have previously shown that Syk also mediates immunoreceptor-like signals required for the in vitro development and function of osteoclasts. However, the perinatal lethality of Syk<sup>â/â</sup> mice precluded the analysis of the role of Syk in in vivo bone metabolism. To overcome that problem, we generated mice with osteoclast-specific (Syk<sup>ÎOC</sup>) or hematopoietic (Syk<sup>ÎHaemo</sup>) Syk deficiency by conditional deletion of Syk using Cre recombinase expressed under the control of the Ctsk or Vav1 promoter, respectively. Micro-CT analysis revealed increased bone trabecular density in both Syk<sup>ÎOC</sup> and Syk<sup>ÎHaemo</sup> mice, although hematopoietic Syk deficiency caused a more severe phenotype than osteoclast-specific Syk deficiency. Osteoclast-specific Syk deficiency reduced, whereas hematopoietic Syk deficiency completely blocked in vitro development of osteoclasts. Both interventions inhibited the resorptive activity of osteoclasts and osteoclast-specific gene expression. Kinetic analysis of Syk protein levels, Cre expression and the genomic deletion of the Syk<sup>flox</sup> allele revealed complete and early deletion of Syk from Syk<sup>ÎHaemo</sup> osteoclasts whereas Syk was incompletely deleted at a later stage of osteoclast development from Syk<sup>ÎOC</sup> cultures. Those results provide an explanation for the in vivo and in vitro difference between the Syk<sup>ÎOC</sup> and Syk<sup>ÎHaemo</sup> mutant strains and suggest late activation of, and incomplete target gene deletion upon, osteoclast-specific Cre expression driven by the Ctsk promoter. Taken together, our results indicate that Syk plays an indispensable role in osteoclast-mediated in vivo bone resorption and suggest that Syk-specific inhibitors may provide therapeutic benefit in inflammatory and other diseases characterized by excessive osteoclast-mediated bone resorption.</p
The 49a,f haplotype 11 is a new marker of the EU19 lineage that traces migrations from northern regions of the Black Sea
Previous studies on human Y-chromosome polymorphisms in the European populations highlighted the high frequency of the 49a,f/TaqI haplotype 11 and of the Eu19 (M17) lineage in Eastern Europe. To better understand the origin and the evolution of the Eu19, and its relationship with 49a,f Ht11, this study surveyed 2,235 individuals (mainly from Europe and the Middle East) for the 49a,f Ht11 and for many biallelic markers defining the Eu19 lineage. As previously described, the highest frequency of Eu19 was found in Eastern Europe. All the Eu19 Y-chromosomes turned out to be 49a,f Ht11 or its derivatives, the distribution of which suggests that the Eu19/49a,f Ht11 emerged in Ukraine, probably in a Palaeolithic population. Thereafter, the spread of this lineage toward Europe, Asia, and India occurred at different waves over a few thousands years. At present this seems to indicate the influence of the Ukraine Palaeolithic groups in the gene pool of modern populations. For the first time it is possible to make inferences about the evolution of some haplotypes of the 49a,f system. In spite of its unknown molecular base, this is one of the first most informative polymorphisms of the Y chromosome
Neutrophil-specific deletion of the CARD9 gene expression regulator suppresses autoantibody-induced inflammation in vivo
Neutrophils are terminally differentiated cells with limited transcriptional activity. The biological function of their gene expression changes is poorly understood. CARD9 regulates transcription during antifungal immunity but its role in sterile inflammation is unclear. Here we show that neutrophil CARD9 mediates pro-inflammatory chemokine/cytokine but not lipid mediator release during non-infectious inflammation. Genetic deficiency of CARD9 suppresses autoantibody-induced arthritis and dermatitis in mice. Neutrophil-specific deletion of CARD9 is sufficient to induce that phenotype. Card9(-/-) neutrophils show defective immune complex-induced gene expression changes and pro-inflammatory chemokine/cytokine release but normal LTB4 production and other short-term responses. In vivo deletion of CARD9 reduces tissue levels of pro-inflammatory chemokines and cytokines but not LTB4. The CARD9-mediated signalling pathway involves Src-family kinases, Syk, PLCÎł2, Bcl10/Malt1 and NFÎșB. Collectively, CARD9-mediated gene expression changes within neutrophils play important roles during non-infectious inflammation in vivo and CARD9 acts as a divergence point between chemokine/cytokine and lipid mediator release
Manufacturing process of a brain aneurysm biomodel in PDMS using rapid prototyping
Cerebral aneurysm is an abnormal dilatation of the blood vessel into a saccular form. They can originate in congenital defects, weakening of the arterial wall with increasing age, atherosclerotic changes, trauma and infectious emboli.
The in vivo experiments are an effective way of investigating the appearance, validating new practices and techniques, but beyond ethical issues, these types of experiments are expensive and have low reproducibility. Thus, to better understand the pathophysiological and geometric aspects of an aneurysm, it is important to fabricate in vitro models capable of improving existing endovascular treatments, developing and validating theoretical and computational models. Another difficulty is in the preoperative period of the non-ruptured cerebral aneurysm, known for the success of the skilled acts because there is an anatomical structure of the aneurysm as its current position. Although there are technologies that facilitate three-dimensional video visualization in the case of aneurysms with complex geometries the operative planning is still complicated, so the development of the real three-dimensional physical model becomes advantageous. In this work, the entire process of manufacturing an aneurysm biomodel using polydimethylsiloxane (PDMS) is disassembled by rapid prototyping technology. The manufactured biomodels are able to perform different hemodynamic studies, validate theoretical data, numerical simulations and assist in the preoperative planning.info:eu-repo/semantics/publishedVersio
In vitro inhibitory activities of selected Australian medicinal plant extracts against protein glycation, angiotensin converting enzyme (ACE) and digestive enzymes linked to type II diabetes
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background
There is a need to develop potential new therapies for the management of diabetes and hypertension. Australian medicinal plants collected from the Kuuku Iâyu (Northern Kaanju) homelands, Cape York Peninsula, Queensland, Australia were investigated to determine their therapeutic potential. Extracts were tested for inhibition of protein glycation and key enzymes relevant to the management of hyperglycaemia and hypertension. The inhibitory activities were further correlated with the antioxidant activities.
Methods
Extracts of five selected plant species were investigated: Petalostigma pubescens, Petalostigma banksii, Memecylon pauciflorum, Millettia pinnata and Grewia mesomischa. Enzyme inhibitory activity of the plant extracts was assessed against α-amylase, α-glucosidase and angiotensin converting enzyme (ACE). Antiglycation activity was determined using glucose-induced protein glycation models and formation of protein-bound fluorescent advanced glycation endproducts (AGEs). Antioxidant activity was determined by measuring the scavenging effect of plant extracts against 1, 1-diphenyl-2-picryl hydrazyl (DPPH) and using the ferric reducing anti-oxidant potential assay (FRAP). Total phenolic and flavonoid contents were also determined.
Results
Extracts of the leaves of Petalostigma banksii and P. pubescens showed the strongest inhibition of α-amylase with IC50 values of 166.50â±â5.50 ÎŒg/mL and 160.20â±â27.92 ÎŒg/mL, respectively. The P. pubescens leaf extract was also the strongest inhibitor of α-glucosidase with an IC50 of 167.83â±â23.82 ÎŒg/mL. Testing for the antiglycation potential of the extracts, measured as inhibition of formation of protein-bound fluorescent AGEs, showed that P. banksii root and fruit extracts had IC50 values of 34.49â±â4.31 ÎŒg/mL and 47.72â±â1.65 ÎŒg/mL, respectively, which were significantly lower (pâ<â0.05) than other extracts. The inhibitory effect on α-amylase, α-glucosidase and the antiglycation potential of the extracts did not correlate with the total phenolic, total flavonoid, FRAP or DPPH. For ACE inhibition, IC50 values ranged between 266.27â±â6.91 to 695.17â±â15.38 ÎŒg/mL.
Conclusions
The tested Australian medicinal plant extracts inhibit glucose-induced fluorescent AGEs, α-amylase, α-glucosidase and ACE with extracts of Petalostigma species showing the most promising activity. These medicinal plants could potentially be further developed as therapeutic agents in the treatment of hyperglycaemia and hypertension
Dissemination of Drinking Water Contamination Data to Consumers: A Systematic Review of Impact on Consumer Behaviors
Drinking water contaminated by chemicals or pathogens is a major public health threat in the developing world. Responses to this threat often require water consumers (households or communities) to improve their own management or treatment of water. One approach hypothesized to increase such positive behaviors is increasing knowledge of the risks of unsafe water through the dissemination of water contamination data. This paper reviews the evidence for this approach in changing behavior and subsequent health outcomes.A systematic review was conducted for studies where results of tests for contaminants in drinking water were disseminated to populations whose water supply posed a known health risk. Studies of any design were included where data were available from a contemporaneous comparison or control group. Using multiple sources >14,000 documents were located. Six studies met inclusion criteria (four of arsenic contamination and two of microbiological contamination). Meta-analysis was not possible in most cases due to heterogeneity of outcomes and study designs. Outcomes included water quality, change of water source, treatment of water, knowledge of contamination, and urinary arsenic. Source switching was most frequently reported: of 5 reporting studies 4 report significantly higher rates of switching (26â72%) among those who received a positive test result and a pooled risk difference was calculate for 2 studies (RDâ=â0.43 [CI0.4.0â0.46] 6â12 months post intervention) suggesting 43% more of those with unsafe wells switched source compared to those with safe wells. Strength of evidence is low since the comparison is between non-equivalent groups. Two studies concerning fecal contamination reported non-significant increases in point-of-use water treatment.Despite the publication of some large cohort studies and some encouraging results the evidence base to support dissemination of contamination data to improve water management is currently equivocal. Rigorous studies on this topic are needed, ideally using common outcome measures
Analgesic and Anti-Inflammatory Effects of the Novel Semicarbazide-Sensitive Amine-Oxidase Inhibitor SzV-1287 in Chronic Arthritis Models of the Mouse.
Semicarbazide-sensitive amine oxidase (SSAO) catalyses oxidative deamination of primary amines. Since there is no data about its function in pain and arthritis mechanisms, we investigated the effects of our novel SSAO inhibitor SzV-1287 in chronic mouse models of joint inflammation. Effects of SzV-1287 (20 mg/kg i.p./day) were investigated in the K/BxN serum-transfer and complete Freund's adjuvant (CFA)-evoked active immunization models compared to the reference SSAO inhibitor LJP-1207. Mechanonociception was assessed by aesthesiometry, oedema by plethysmometry, clinical severity by scoring, joint function by grid test, myeloperoxidase activity by luminescence, vascular leakage by fluorescence in vivo imaging, histopathological changes by semiquantitative evaluation, and cytokines by Luminex assay. SzV-1287 significantly inhibited hyperalgesia and oedema in both models. Plasma leakage and keratinocyte chemoattractant production in the tibiotarsal joint, but not myeloperoxidase activity was significantly reduced by SzV-1287 in K/BxN-arthritis. SzV-1287 did not influence vascular and cellular mechanisms in CFA-arthritis, but significantly decreased histopathological alterations. There was no difference in the anti-hyperalgesic and anti-inflammatory actions of SzV-1287 and LJP-1207, but only SzV-1287 decreased CFA-induced tissue damage. Unlike SzV-1287, LJP-1207 induced cartilage destruction, which was confirmed in vitro. SzV-1287 exerts potent analgesic and anti-inflammatory actions in chronic arthritis models of distinct mechanisms, without inducing cartilage damage
Functional Evolution of Leptin of Ochotona curzoniae in Adaptive Thermogenesis Driven by Cold Environmental Stress
BACKGROUND: Environmental stress can accelerate the directional selection and evolutionary rate of specific stress-response proteins to bring about new or altered functions, enhancing an organism's fitness to challenging environments. Plateau pika (Ochotona curzoniae), an endemic and keystone species on Qinghai-Tibetan Plateau, is a high hypoxia and low temperature tolerant mammal with high resting metabolic rate and non-shivering thermogenesis to cope in this harsh plateau environment. Leptin is a key hormone related to how these animals regulate energy homeostasis. Previous molecular evolutionary analysis helped to generate the hypothesis that adaptive evolution of plateau pika leptin may be driven by cold stress. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis, recombinant pika leptin was first purified. The thermogenic characteristics of C57BL/6J mice injected with pika leptin under warm (23±1°C) and cold (5±1°C) acclimation is investigated. Expression levels of genes regulating adaptive thermogenesis in brown adipose tissue and the hypothalamus are compared between pika leptin and human leptin treatment, suggesting that pika leptin has adaptively and functionally evolved. Our results show that pika leptin regulates energy homeostasis via reduced food intake and increased energy expenditure under both warm and cold conditions. Compared with human leptin, pika leptin demonstrates a superior induced capacity for adaptive thermogenesis, which is reflected in a more enhanced ÎČ-oxidation, mitochondrial biogenesis and heat production. Moreover, leptin treatment combined with cold stimulation has a significant synergistic effect on adaptive thermogenesis, more so than is observed with a single cold exposure or single leptin treatment. CONCLUSIONS/SIGNIFICANCE: These findings support the hypothesis that cold stress has driven the functional evolution of plateau pika leptin as an ecological adaptation to the Qinghai-Tibetan Plateau
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