University of Geneva

About: University of Geneva is a education organization based out in Geneva, Switzerland. It is known for research contribution in the topics: Population & Galaxy. The organization has 26887 authors who have published 65265 publications receiving 2931373 citations. The organization is also known as: Geneva University & Universite de Geneve.

GLUTAMATE RECEPTOR-LIKE genes mediate leaf-to-leaf wound signalling

Abstract: Wounded leaves communicate their damage status to one another through a poorly understood process of long-distance signalling. This stimulates the distal production of jasmonates, potent regulators of defence responses. Using non-invasive electrodes we mapped surface potential changes in Arabidopsis thaliana after wounding leaf eight and found that membrane depolarizations correlated with jasmonate signalling domains in undamaged leaves. Furthermore, current injection elicited jasmonoyl-isoleucine accumulation, resulting in a transcriptome enriched in RNAs encoding key jasmonate signalling regulators. From among 34 screened membrane protein mutant lines, mutations in several clade 3 GLUTAMATE RECEPTOR-LIKE genes (GLRs 3.2, 3.3 and 3.6) attenuated wound-induced surface potential changes. Jasmonate-response gene expression in leaves distal to wounds was reduced in a glr3.3 glr3.6 double mutant. This work provides a genetic basis for investigating mechanisms of long-distance wound signalling in plants and indicates that plant genes related to those important for synaptic activity in animals function in organ-to-organ wound signalling.

Prevalence of IgE-mediated food allergy among children with atopic dermatitis.

Abstract: Objective. There is a growing body of clinical and laboratory evidence to support the notion that food allergy plays a role in the pathogenesis of atopic dermatitis (AD). However, the incidence of IgE-mediated food allergy in children with AD is not well established. Design. A prospective study to determine the prevalence of IgE-mediated food hypersensitivity among patients referred to a university-based dermatologist for evaluation of AD. Setting. University hospital pediatric dermatology clinic. Patients. A total of 63 patients with AD were recruited (35 male; 32 white, 24 African-American, 7 Asian). Methods. Patients were assigned an AD symptom score (SCORAD) and were screened for food-specific serum IgE antibodies to six foods (milk, egg, wheat, soy, peanut, fish) known to be the most allergenic in children. The levels of food-specific serum IgE were determined by the CAP System fluoroscein-enzyme immunoassay (CAP); patients with a value ≥0.7 kIUa/L were invited for an additional allergy evaluation. Those with CAP values below the cutoff were considered not food allergic. Patients were considered to be allergic if they met one of the following criteria for at least one food: 1) reaction on food challenge; 2) CAP value more than the 95% confidence interval predictive for a reaction; 3) convincing history of an acute significant (hives, respiratory symptoms) reaction after the isolated ingestion of a food to which there was a positive CAP or prick skin test. Results. A total of 63 patients (median age, 2.8 years; median SCORAD, 41.1) were recruited; 22 had negative CAP values (without a significant difference in age or SCORAD score, compared with the 41 with positive specific IgE values). Further allergy evaluation was offered to the 41 remaining patients; 10 were lost to follow-up and 31 were evaluated further. Of these, 19 underwent a total of 50 food challenges (36 double-blind, placebo-controlled, and 14 open), with 11 patients experiencing 18 positive challenges (94% with skin reactions). Additionally, 6 patients had a convincing history with a predictive level of IgE; 5 had a convincing history with positive, indeterminate levels of IgE; and 1 had predictive levels of IgE (to egg and peanut) without a history of an acute reaction. Overall, 23/63 (37%; 95% confidence interval, 25% to 50%) had clinically significant IgE-mediated food hypersensitivity without a significant difference in age or symptom score between those with or without food allergy. Conclusions. Approximately one third of children with refractory, moderate–severe AD have IgE-mediated clinical reactivity to food proteins. The prevalence of food allergy in this population is significantly higher than that in the general population, and an evaluation for food allergy should be considered in these patients.

Studies of the diabetogenic action of streptozotocin.

Abstract: SummaryStreptozotocin is a highly effective cytotoxic agent for pancreatic B-cells. After intravenous administration of 65 mg streptozotocin per kg, damage to B-cells is apparent as early as one hour after intravenous administration of the drug. Frank necrosis associated with phagocytosis is best seen after 7 hours, when pancreatic insulin release and hypoglycemia are also noted. By 24 hours, pancreatic insulin content is reduced to 5% of normal or less. While the B-cytotoxic effects of streptozotocin resemble those of alloxan, their specificity is very much greater, as demonstrated by the wide margin between diabetogenic dose and general toxicity.

Global judgments of subjective well-being: Situational variability and long-term stability.

Abstract: Subjective well-being (SWB) is an important indicator of quality oflife. SWB can be conceptualized as a momentary state (e.g., mood) aswell as a relatively stable trait (e.g., life satisfaction). Thevalidity of self-reported trait aspects of SWB has been questioned byexperimental studies showing that SWB judgments seem to be stronglycontext dependent. Particularly, momentary mood seems to have a stronginfluence on global SWB judgments. To explore the ecological validity ofthese conclusions a non-experimental longitudinal self-reportstudy with three occasions of measurement was conducted(N = 249). The associations between momentarymood ratings and global judgments of SWB (life satisfaction,satisfaction with life domains, frequency and intensity of emotions) aswell as personality ratings (self-esteem, optimism, neuroticism,extraversion) were analyzed in a multistate-multitrait-multiconstructmodel. This model takes (a) measurement error, (b) occasion-specificdeviations, and (c) stable interindividual differences into account. Itis shown that the variability in global SWB judgments and personalityratings is relatively small and much smaller than the variability inmood. Furthermore, the occasion-specific associations between moodstates, on the one hand, and global SWB and personality ratings, on theother hand, are relatively small and inconsistent. All global SWB andpersonality variables are more strongly related to mood on the traitlevel than on the occasion-specific deviation level. Therefore, incontrast to experimental studies, occasion-specific mood effects do notseem to be inherently important in ecological measurement settings.

Chronic Palmitate But Not Oleate Exposure Induces Endoplasmic Reticulum Stress, Which May Contribute to INS-1 Pancreatic β-Cell Apoptosis

Abstract: Chronic free fatty acid (FFA) exposure induces pancreatic beta-cell death, which may contribute to the development of type 2 diabetes. The mechanisms involved in FFA-induced cell death are not completely understood. Here we have investigated the effect of FFA on endoplasmic reticulum (ER) stress pathways in INS-1 pancreatic beta-cells. INS-1 cells exposed to palmitate for 16-24 h under serum-free conditions showed marked apoptosis and increased protein levels of phosphorylated eukaryotic translation initiation factor 2alpha (eIF2alpha), activating transcription factor 4 (ATF4), X box-binding protein 1 (XBP-1), and C/EBP homologous transcription factor (CHOP) compared with control cells. The CHOP transcription factor has been implicated in mediating ER stress-induced apoptosis. Unexpectedly, the levels of the ER chaperone proteins Grp78/BiP and PDI were not affected by palmitate treatment, suggesting that the cell protective aspects of the unfolded protein response (UPR) are not up-regulated by palmitate. Palmitate-treated cells had markedly altered distribution of ER chaperones and altered ER morphology, suggesting that accumulation of misfolded proteins might trigger the ER stress response. In contrast, oleate treatment did not significantly induce the UPR pathways, nor was it as detrimental to INS-1 beta-cells. The results suggest that activation of the UPR may significantly contribute to palmitate- but not oleate-induced pancreatic beta-cell death.