223 research outputs found

    Ethanol-induced Modulation of Hepatocellular Extracellular Signal-regulated Kinase-1/2 Activity via 4-Hydroxynonenal

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    Modulation of the extracellular signal-regulated kinases (ERK-1/2), a signaling pathway directly associated with cell proliferation, survival, and homeostasis, has been implicated in several pathologies, including alcoholic liver disease. However, the underlying mechanism of ethanol-induced ERK-1/2 modulation remains unknown. This investigation explored the effects of ethanol-associated oxidative stress on constitutive hepatic ERK-1/2 activity and assessed the contribution of the lipid peroxidation product 4-hydroxynonenal (4-HNE) to the observations made in vivo. Constitutive ERK-1/2 phosphorylation was suppressed in hepatocytes isolated from rats chronically consuming ethanol for 45 days. This observation was associated with an increase in 4-HNE-ERK monomer adduct concentration and a hepatic cellular and lobular redistribution of ERK-1/2 that correlated with 4-HNE-protein adduct accumulation. Chronic ethanol consumption was also associated with a decrease in hepatocyte nuclear ELK-1 phosphorylation, independent of changes in total nuclear ELK-1 protein. Primary hepatocytes treated with concentrations of 4-HNE consistent with those occurring during oxidative stress displayed a concentration-dependent decrease in constitutive ERK-1/2 phosphorylation, activity, and nuclear localization that negatively correlated with 4-HNE-ERK-1/2 monomer adduct accumulation. These data paralleled the decreased phosphorylation of the downstream kinase ELK-1. Molar ratios of purified ERK-2 to 4-HNE consistent with pathologic ratios found in vivo resulted in protein monomer-adduct formation across a range of concentrations. Collectively, these data demonstrate a novel association between ethanol-induced lipid peroxidation and the inhibition of constitutive ERK-1/2, and suggest an inhibitory mechanism mediated by the lipid peroxidation product 4-hydroxynonenal

    Professionalism and the Millbank Tendency: The Political Sociology of New Labour's employees

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    This article analyses party employees, one of the most under-researched subjects in the study of British political parties. We draw on a blend of quantitative and qualitative data in order to shed light on the social and political profiles of Labour Party staff, and on the question of their professionalisation. The latter theme is developed through a model derived from the sociology of professions. While a relatively limited proportion of party employees conform to the pure ideal-type of professionalism, a considerably greater number manifest enough of the core characteristics of specialisation, commitment, mobility, autonomy and self-regulation to be reasonably described as 'professionals in pursuit of political outcomes'

    The influence of glacial melt and retreat on the nutritional condition of the bivalve Nuculana inaequisculpta (Protobranchia: Nuculanidae) in the West Antarctic Peninsula

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    Due to climate change, numerous ice bodies have been lost in the West Antarctic Peninsula (WAP). As a consequence, deglaciation is expected to impact the marine environment and its biota at physiological and ecosystem levels. Nuculana inaequisculpta is a marine bivalve widely distributed around Antarctica that plays an important role for ecosystem functioning. Considering that N. inaequisculpta inhabits coastal areas under effect of glacial melt and retreat, impacts on its nutritional condition are expected due to alterations on its physiology and food availability. To test this hypothesis, biochemical composition (lipids, proteins, and fatty acids) and energy content were measured in individuals of N. inaequisculpta collected in a fjord at different distances to the retreating glacier in the WAP. Oceanographic parameters of the top and bottom-water layers (temperature, salinity, dissolved oxygen, and chlorophyll-a) were measured to investigate how the environment changes along the fjord. Results showed that surface oceanographic parameters displayed a lower temperature and dissolved oxygen, but a higher salinity and chlorophyll-a content at nearest compared to farthest sites to the glacier. In contrast, a lower temperature and chlorophyll-a, and a higher salinity and dissolved oxygen was measured in the bottom-water layer toward the glacier. N. inaequisculpta had a higher amount of lipids (17.42 Âą 3.24 vs. 12.16 Âą 3.46%), protein (24.34 Âą 6.12 vs. 21.05 Âą 2.46%) and energy content (50.57 Âą 6.97 J vs. 39.14 Âą 5.80 J) in the farthest compared to the nearest site to the glacier. No differences were found in total fatty acids among all sites. It seems likely that lower individual fitness related to proximity to the glacier would not be related to nutritional quality of sediment food, but rather to food quantity

    Going beyond children’s single-text comprehension:The role of fundamental and higher–level skills in 4th graders’ multiple-document comprehension

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    Background: Children's comprehension of single texts relies on both foundational and higher-level skills. These are also assumed to support multiple-document comprehension, but their relative importance has not been examined, to date. Multiple-document comprehension additionally requires the identification and use of information about each document's source. Aims: This study examined multiple-document comprehension in primary school-aged children. It sought to determine the relative importance of skills proposed to be common to both single-text and multiple-document comprehension (word reading fluency, verbal working memory, comprehension monitoring) and specific to the latter (source use). Single-text comprehension and prior topic knowledge were considered as moderator and control. Sample: Participants were 94 children in the fourth year (mean age = 9; 7 years; 52% females). Methods: Children read three documents on each of two topics (chocolate and video games). Multiple-document comprehension and source use were assessed through short essays. Independent measures of the fundamental and higher-level skills were used. Results: There was a significant direct and indirect influence of word reading fluency on comprehension of multiple documents on videogames and also an indirect influence of comprehension monitoring. Indirect influences of word reading fluency and comprehension monitoring on multiple-document comprehension for both topics were also apparent. Verbal working memory was not a unique predictor. When source information was identified, it was included to support the argument in the composition. Conclusions: Efficient word reading, comprehension monitoring, and single-text comprehension are important for multiple-document comprehension in young readers. Implications of these findings and differences between the two document sets are discussed

    Gene flow in the Antarctic bivalve Aequiyoldia eightsii (Jay, 1839) suggests a role for the Antarctic Peninsula Coastal Current in larval dispersal

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    The Antarctic Circumpolar Current (ACC) dominates the open-ocean circulation of the Southern Ocean, and both isolates and connects the Southern Ocean biodiversity. However, the impact on biological processes of other Southern Ocean currents is less clear. Adjacent to the West Antarctic Peninsula (WAP), the ACC flows offshore in a northeastward direction, whereas the Antarctic Peninsula Coastal Current (APCC) follows a complex circulation pattern along the coast, with topographically influenced deflections depending on the area. Using genomic data, we estimated genetic structure and migration rates between populations of the benthic bivalve Aequiyoldia eightsii from the shallows of southern South America and the WAP to test the role of the ACC and the APCC in its dispersal. We found strong genetic structure across the ACC (between southern South America and Antarctica) and moderate structure between populations of the WAP. Migration rates along the WAP were consistent with the APCC being important for species dispersal. Along with supporting current knowledge about ocean circulation models at the WAP, migration from the tip of the Antarctic Peninsula to the Bellingshausen Sea highlights the complexities of Southern Ocean circulation. This study provides novel biological evidence of a role of the APCC as a driver of species dispersal and highlights the power of genomic data for aiding in the understanding of the influence of complex oceanographic processes in shaping the population structure of marine species

    Struggling for recognition and inclusion—parents' and pupils' experiences of special support measures in school

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    During the last decade an increasing use of differentiated support measures for pupils with special educational needs, indicative of a discrepancy between educational policies and practices, has been witnessed in Sweden. Another trend has been the increased use of medical diagnoses in school. The aim of this study was to explore the main concern of support given to pupils with special educational needs and how pupils and parents experience and handle this. Interviews were conducted with eight pupils in Grades 7–9—and their parents—at two compulsory schools in a city in northern Sweden. A grounded theory approach was used for analyzing the interview data. A conceptual model was generated illuminating the main concern of special support measures for pupils and parents. The core category of the model, struggling for recognition and inclusion, was related to two categories, which further described how this process was experienced and handled by the participants. These categories were labeled negotiating expertise knowledge within a fragmented support structure and coping with stigma, ambivalence, and special support measures. The developed conceptual model provides a deeper understanding of an ongoing process of struggle for recognition and inclusion in school as described by the pupils and parents

    Metabolic reprogramming through fatty acid transport protein 1 (FATP1) regulates macrophage inflammatory potential and adipose inflammation

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    OBJECTIVE: A novel approach to regulate obesity-associated adipose inflammation may be through metabolic reprogramming of macrophages (MÎŚs). Broadly speaking, MÎŚs dependent on glucose are pro-inflammatory, classically activated MÎŚs (CAM), which contribute to adipose inflammation and insulin resistance. In contrast, MÎŚs that primarily metabolize fatty acids are alternatively activated MÎŚs (AAM) and maintain tissue insulin sensitivity. In actuality, there is much flexibility and overlap in the CAM-AAM spectrum in vivo dependent upon various stimuli in the microenvironment. We hypothesized that specific lipid trafficking proteins, e.g. fatty acid transport protein 1 (FATP1), would direct MÎŚ fatty acid transport and metabolism to limit inflammation and contribute to the maintenance of adipose tissue homeostasis. METHODS: Bone marrow derived MÎŚs (BMDMs) from Fatp1 (-/-) and Fatp1 (+/+) mice were used to investigate FATP1-dependent substrate metabolism, bioenergetics, metabolomics, and inflammatory responses. We also generated C57BL/6J chimeric mice by bone marrow transplant specifically lacking hematopoetic FATP1 (Fatp1 (B-/-)) and controls Fatp1 (B+/+). Mice were challenged by high fat diet (HFD) or low fat diet (LFD) and analyses including MRI, glucose and insulin tolerance tests, flow cytometric, histologic, and protein quantification assays were conducted. Finally, an FATP1-overexpressing RAW 264.7 MÎŚ cell line (FATP1-OE) and empty vector control (FATP1-EV) were developed as a gain of function model to test effects on substrate metabolism, bioenergetics, metabolomics, and inflammatory responses. RESULTS: Fatp1 is downregulated with pro-inflammatory stimulation of MÎŚs. Fatp1 (-/-) BMDMs and FATP1-OE RAW 264.7 MÎŚs demonstrated that FATP1 reciprocally controled metabolic flexibility, i.e. lipid and glucose metabolism, which was associated with inflammatory response. Supporting our previous work demonstrating the positive relationship between glucose metabolism and inflammation, loss of FATP1 enhanced glucose metabolism and exaggerated the pro-inflammatory CAM phenotype. Fatp1 (B-/-) chimeras fed a HFD gained more epididymal white adipose mass, which was inflamed and oxidatively stressed, compared to HFD-fed Fatp1 (B+/+) controls. Adipose tissue macrophages displayed a CAM-like phenotype in the absence of Fatp1. Conversely, functional overexpression of FATP1 decreased many aspects of glucose metabolism and diminished CAM-stimulated inflammation in vitro. FATP1 displayed acyl-CoA synthetase activity for long chain fatty acids in MÎŚs and modulated lipid mediator metabolism in MÎŚs. CONCLUSION: Our findings provide evidence that FATP1 is a novel regulator of MÎŚ activation through control of substrate metabolism. Absence of FATP1 exacerbated pro-inflammatory activation in vitro and increased local and systemic components of the metabolic syndrome in HFD-fed Fatp1 (B-/-) mice. In contrast, gain of FATP1 activity in MÎŚs suggested that Fatp1-mediated activation of fatty acids, substrate switch to glucose, oxidative stress, and lipid mediator synthesis are potential mechanisms. We demonstrate for the first time that FATP1 provides a unique mechanism by which the inflammatory tone of adipose and systemic metabolism may be regulated

    Antiproliferative and metabolic effects of metformin in a preoperative window clinical trial for endometrial cancer

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    We conducted a preoperative window study of metformin in endometrial cancer (EC) patients and evaluated its antiproliferative, molecular and metabolic effects. Twenty obese women with endometrioid EC were treated with metformin (850mg) daily for up to 4weeks prior to surgical staging. Expression of the proliferation marker Ki-67, estrogen receptor (ER), progesterone receptor (PR), adenosine monophosphate-activated protein kinase (AMPK), and downstream targets of the mammalian target of rapamycin (mTOR) pathway were measured by immunohistochemistry. Global, untargeted metabolomics analysis of serum pre- and postmetformin treatment, and matched tumor, was performed. Metformin reduced proliferation by 11.75% (P=0.008) based on the comparison of pre- and posttreatment endometrial tumors. A total of 65% of patients responded to metformin as defined by a decrease in Ki-67 staining in their endometrial tumors post-treatment. Metformin decreased expression of phosphorylated (p)-AMPK (P=0.00001), p-Akt (P=0.0002), p-S6 (51.2%, P=0.0002), p-4E-BP-1 (P=0.001), and ER (P=0.0002) but not PR expression. Metabolomic profiling of serum indicated that responders versus nonresponders to treatment were more sensitive to metformin's effects on induction of lipolysis, which correlated with increased fatty acid oxidation and glycogen metabolism in matched tumors. In conclusion, metformin reduced tumor proliferation in a pre-operative window study in obese EC patients, with dramatic effects on inhibition of the mTOR pathway. Metformin induced a shift in lipid and glycogen metabolism that was more pronounced in the serum and tumors of responders versus nonresponders to treatment.This study provides support for therapeutic clinical trials of metformin in obese patients with EC

    Cafeteria Diet Is a Robust Model of Human Metabolic Syndrome With Liver and Adipose Inflammation: Comparison to High-Fat Diet

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    Obesity has reached epidemic proportions worldwide and reports estimate that American children consume up to 25% of calories from snacks. Several animal models of obesity exist, but studies are lacking that compare high-fat diets (HFD) traditionally used in rodent models of diet-induced obesity (DIO) to diets consisting of food regularly consumed by humans, including high-salt, high-fat, low-fiber, energy dense foods such as cookies, chips, and processed meats. To investigate the obesogenic and inflammatory consequences of a cafeteria diet (CAF) compared to a lard-based 45% HFD in rodent models, male Wistar rats were fed HFD, CAF or chow control diets for 15 weeks. Body weight increased dramatically and remained significantly elevated in CAF-fed rats compared to all other diets. Glucose- and insulin-tolerance tests revealed that hyperinsulinemia, hyperglycemia, and glucose intolerance were exaggerated in the CAF-fed rats compared to controls and HFD-fed rats. It is well-established that macrophages infiltrate metabolic tissues at the onset of weight gain and directly contribute to inflammation, insulin resistance, and obesity. Although both high fat diets resulted in increased adiposity and hepatosteatosis, CAF-fed rats displayed remarkable inflammation in white fat, brown fat and liver compared to HFD and controls. In sum, the CAF provided a robust model of human metabolic syndrome compared to traditional lard-based HFD, creating a phenotype of exaggerated obesity with glucose intolerance and inflammation. This model provides a unique platform to study the biochemical, genomic and physiological mechanisms of obesity and obesity-related disease states that are pandemic in western civilization today
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