20 research outputs found
Distinctions between experiences of anger and sadness in children's and adolescents' narrative accounts of peer injury
Childrenâs varied emotions following peer injury may reflect distinct ways of understanding and coping with such events. This study examined how childrenâs references to anger and sadness in their accounts of peer injury were differentially related to narrative descriptions of their motivations, interpretations, evaluations, and behavioral responses, as well as the relationships in which harm occurred. We also explored how these associations between emotions and other narrative elements varied with age. The study was based on a corpus of 275 transcripts of oral narratives recounted by equal numbers of boys and girls across three age groups: 7, 11, and 16 years. In line with functionalist theories, anger was uniquely linked to maximizing attributions, indignation, and aggression, after accounting for age and gender. Sadness was related to harm in close relationships and relational goals, underlining the value placed on relationships with the offender, as well as a sense of powerlessness and confusion. Some associations between emotions and other narrative elements varied with age, suggesting that childrenâs experiences of anger and sadness became increasingly agentic and relationally oriented. Findings suggest how narrative constructions of meaning about peer injury may serve as contexts for reflecting on how anger and sadness emerge from and are resolved through interpersonal relationships
Heterologous Expression of Membrane Proteins: Choosing the Appropriate Host
International audienceBACKGROUND: Membrane proteins are the targets of 50% of drugs, although they only represent 1% of total cellular proteins. The first major bottleneck on the route to their functional and structural characterisation is their overexpression; and simply choosing the right system can involve many months of trial and error. This work is intended as a guide to where to start when faced with heterologous expression of a membrane protein. METHODOLOGY/PRINCIPAL FINDINGS: The expression of 20 membrane proteins, both peripheral and integral, in three prokaryotic (E. coli, L. lactis, R. sphaeroides) and three eukaryotic (A. thaliana, N. benthamiana, Sf9 insect cells) hosts was tested. The proteins tested were of various origins (bacteria, plants and mammals), functions (transporters, receptors, enzymes) and topologies (between 0 and 13 transmembrane segments). The Gateway system was used to clone all 20 genes into appropriate vectors for the hosts to be tested. Culture conditions were optimised for each host, and specific strategies were tested, such as the use of Mistic fusions in E. coli. 17 of the 20 proteins were produced at adequate yields for functional and, in some cases, structural studies. We have formulated general recommendations to assist with choosing an appropriate system based on our observations of protein behaviour in the different hosts. CONCLUSIONS/SIGNIFICANCE: Most of the methods presented here can be quite easily implemented in other laboratories. The results highlight certain factors that should be considered when selecting an expression host. The decision aide provided should help both newcomers and old-hands to select the best system for their favourite membrane protein
Checking the garbage bin for problems in the house, or how autophagy assists in antigen presentation to the immune system
Macroautophagy was originally discovered as a nutrient salvage pathway during starvation. By now it has not only become clear that degradation of cytoplasmic constituents via transport by autophagosomes to lysosomes can be used for innate and adaptive immunity, but that the core machinery assists antigen presentation to the immune system by a variety of vesicular transport pathways. All of these rely on the presentation of small protein waste fragments, which are generated by a variety of catabolic pathways, including macroautophagy, on major histocompatibility complex (MHC) molecules. In this review, we will point out how classical macroautophagy, as well as phagocytosis and exocytosis, which both benefit from the core autophagic machinery, assist in antigen presentation on MHC class I and II molecules to CD8+ and CD4+ T cells, respectively. Finally to high-light that macroautophagy is always intimately interconnected with cell death in addition to the various supported vesicular transport function, its role in lymphocyte, especially T cell, development and function will be discussed. From this body of work a picture is emerging that the core machinery of macroautophagy can be used for a variety of vesicular transport pathways and to modulate cell survival, besides its classical role in delivering intracellular material for lysosomal degradation
Tumor Endothelial Markers Define Novel Subsets of Cancer-Specific Circulating Endothelial Cells Associated with Antitumor Efficacy
Circulating endothelial cells (CEC) are derived from multiple sources, including bone marrow (circulating endothelial progenitors; CEP), and established vasculature (mature CEC). Although CECs have shown promise as a biomarker for patients with cancer, their utility has been limited, in part, by the lack of specificity for tumor vasculature and the different nonmalignant causes that can impact CEC. Tumor endothelial markers (TEM) are antigens enriched in tumor versus nonmalignant endothelia. We hypothesized that TEMs may be detectable on CEC and that these circulating TEM+ endothelial cells (CTEC) may be a more specific marker for cancer and tumor response than standard CEC. We found that tumor-bearing mice had a relative increase in numbers of circulating CTEC, specifically with increased levels of TEM7 and TEM8 expression. Following treatment with various vascular-targeting agents, we observed a decrease in CTEC that correlated with the reductions in tumor growth. We extended these findings to human clinical samples and observed that CTECs were present in patients with esophageal cancer and non-small cell lung cancer (N = 40), and their levels decreased after surgical resection. These results demonstrate that CTECs are detectable in preclinical cancer models and patients with cancer. Furthermore, they suggest that CTECs offer a novel cancer-associated marker that may be useful as a blood-based surrogate for assessing the presence of tumor vasculature and antiangiogenic drug activity. (C)2014 AACR
Antihypertensive and vasorelaxant effects of aqueous extract of Artemisia campestris L. from Eastern Morocco.
ETHNOPHARMACOLOGICAL RELEVANCE: Artemisia campestris L. (Asteraceae) has many traditional uses, among which treatment of diabetes and hypertension. AIM OF THE STUDY: This study was conducted in order to confirm the antihypertensive and hypotensive effects of A. campestris L. aqueous extract (AcAE) and to explore the underlying mechanism of action of its vasorelaxant effect, besides the acute toxicity. Also, the chemical composition of AcAE was investigated. MATERIAL AND METHODS: the chemical content of AcAE was determined by using HPLC and NMR techniques. The antihypertensive effect was assessed indirectly by tail-cuff method on L-NAME induced hypertensive rats, while the hypotensive action was monitored intravenously by invasive method on normotensive rats. The vasorelaxant effect and vascular mechanism of action were studied in the presence of antagonists and blockers on aorta isolated from normotensive rats. On the other side, the acute toxicity was studied by oral feeding of extract to the mice. RESULTS: The global phytochemical profile of AcAE reveals the presence of several polyphenols as main components. A. campestris L. infusion was characterized by mono- and di-cinnamoyl compounds, with 3,5-dicaffeoylquinic (isochlorogenic A) acid being the main compound, followed by 5-caffeoylquinic (chlorogenic) acid. Vicenin-2 (apigenin 6,8-di-C-glucoside) appeared to be the most abundant compound among flavonoids. The daily treatment with AcAE at 150mg/Kg/day prevented the installation of hypertension on L-NAME hypertensive rats, and reduced SBP from 172mmHg up to 144mmHg. At the dose 40mg/Kg, AcAE provoked reduction of systolic (SBP), diastolic (DBP) and mean arterial pressure (MAP), without affecting the heart rate. Also, AcAE (10-2-2mg/ml) relaxed the precontracted aorta by 95.8 +/- 1.3%. The denudation and preincubation of aorta with atropine, calmidazolium, L-NAME, hydroxycobalamin, ODQ, 8-RP-Br-PET-cGMP, thapsigargin and verapamil attenuated the vasorelaxant response, while the pre-treatment with 4-AP, TEA, glibenclamide and BaCl2 did not alter this effect. The oral administration of AcAE (0-6g/Kg) reveals no mortality or toxicity. CONCLUSIONS: our study proved that AcAE possess an important antihypertensive, hypotensive and vasorelaxant effect, which is mediated via calmodulin-NO-cGC-PKG pathway, and via inhibition of calcium influx through voltage-operated calcium channels and activation of intracellular calcium mobilization into sarcoplasmic reticulum. Therefore, our findings give first evidence about the traditional use of A. campestris L. as antihypertensive plant
Dementia Research Fit for the Planet: Reflections on Population Studies of Dementia for Researchers and Policy Makers Alike
In recent years, a rapidly increasing collection of investigative methods in addition to changes in diagnostic criteria
for dementia have followed âhigh-techâ trends in medicine,
with the aim to better define the dementia syndrome and
its biological substrates, mainly in order to predict risk prior
to clinical expression. These approaches are not without
challenge. A set of guidelines have been developed by a
group of European experts in population-based cohort research through a series of workshops, funded by the Joint
Program for Neurodegenerative Disorders (JPND). The aims
of the guidelines are to assist policy makers and researchers
to understand (1) What population studies for ageing populations should encompass and (2) How to interpret the
findings from population studies. Such studies are essential
to provide evidence relevant to the understanding of
healthy and frail brain ageing, including the dementia syndrome for contemporary and future societies by drawing
on the past
Dementia Research Fit for the Planet: Reflections on Population Studies of Dementia for Researchers and Policy Makers Alike
In recent years, a rapidly increasing collection of investigative methods in addition to changes in diagnostic criteria
for dementia have followed âhigh-techâ trends in medicine,
with the aim to better define the dementia syndrome and
its biological substrates, mainly in order to predict risk prior
to clinical expression. These approaches are not without
challenge. A set of guidelines have been developed by a
group of European experts in population-based cohort research through a series of workshops, funded by the Joint
Program for Neurodegenerative Disorders (JPND). The aims
of the guidelines are to assist policy makers and researchers
to understand (1) What population studies for ageing populations should encompass and (2) How to interpret the
findings from population studies. Such studies are essential
to provide evidence relevant to the understanding of
healthy and frail brain ageing, including the dementia syndrome for contemporary and future societies by drawing
on the past
Dementia Research Fit for the Planet: Reflections on Population Studies of Dementia for Researchers and Policy Makers Alike.
In recent years, a rapidly increasing collection of investigative methods in addition to changes in diagnostic criteria for dementia have followed "high-tech" trends in medicine, with the aim to better define the dementia syndrome and its biological substrates, mainly in order to predict risk prior to clinical expression. These approaches are not without challenge. A set of guidelines have been developed by a group of European experts in population-based cohort research through a series of workshops, funded by the Joint Program for Neurodegenerative Disorders (JPND). The aims of the guidelines are to assist policy makers and researchers to understand (1) What population studies for ageing populations should encompass and (2) How to interpret the findings from population studies. Such studies are essential to provide evidence relevant to the understanding of healthy and frail brain ageing, including the dementia syndrome for contemporary and future societies by drawing on the past