Die Rolle exogen zugeführter Zucker in der Hochlicht-Akklimatisierung von Arabidopsis thaliana

Die Arabidopsis thaliana Doppelmutante adg1-1/tpt-2 zeigt, bedingt durch den vollständigen Funktionsverlust des Triosephosphat/Phosphat Translokators (TPT; tpt-2) und einen Defekt der Stärkebiosynthese in Blättern (AGPase; adg1-1), unter Hochlichtbedingungen sowohl einen retardierten Wachstumsphänotyp als auch einen „Hoch-Chlorophyll-Fluoreszenz“-Phänotyp (HCF). Erfolgte die Anzucht auf ½ MS-Agarplatten mit Glucose (Glc) oder Saccharose (Suc) konnten beide Phänotypen gerettet werden. Um eine Beteiligung beider Gene an der zuckerabhängigen Rettung zu prüfen, wurden zusätzlich Tripelmutanten untersucht, die entweder über einen Defekt in der Hexokinase1 (HXK1; gin2-1) oder des Glucose-6-phosphat/Phosphat Translokator2 (GPT2, gpt2-1) verfügen. Wildtypen, sowie Einzel-, Doppel- und Tripelmutanten wurden für die Experimente auf ½ MS-Agarplatten ohne Zucker oder mit Zugabe von jeweils Glc, Suc oder Fructose (Fru) angezogen. Der Wachstumsphänotyp aller Doppel- und Tripelmutanten konnte nur durch Glc und Suc, nicht aber durch Fru gerettet werden. Alle drei Zucker waren hingegen in der Lage, unabhängig von der HXK1, den HCF und auch den Photosynthesephänotyp zu retten. Es ist zu vermuten, dass die direkte Aufnahme von löslichen Zuckern in den Chloroplasten und deren Verstoff-wechselung im Stroma zur Rettung der adg1-1/tpt-2-Phänotypen beiträgt, obwohl der Tag- sowie der Nachtexport von Photoassimilaten blockiert ist. Desweiteren existiert eine direkte Korrelation zwischen der photosynthetischen Elektronentransportrate und dem Kohlenhydratstatus im Mesophyll der adg1-1/tpt-2-Doppelmutante. Damit ergibt sich die Frage über die Fähigkeit von Chloroplasten den metabolischen Ist-Zustand der Zelle wahrzunehmen

Construct and face validity of SINERGIA laparoscopic virtual reality simulator

Purpose Laparoscopic techniques have nowadays become a gold standard in many surgical procedures, but they imply a more difficult learning skills process. Simulators have a fundamental role in the formative stage of new surgeons. This paper presents the construct and face validity of SINERGIA laparoscopic virtual reality simulator in order to decide whether it can be considered as an assessment tool. Methods Twenty people participated in this study, 14 were novices and 6 were experts. Five tasks of SINERGIA were included in the study: coordination, navigation, navigation and touch, precise grasping and coordinate traction. For each one of these tasks, a certain number of metrics are automatically recorded. All subjects accomplished each task only once and filled in two questionnaires. A statistical analysis was made and results from both groups were compared with the Mann–Whitney U-test, considering significant differences when P ≤ 0.05. Internal consistency of the system has been analyzed with the Cronbach’s alpha test. Results Novices and experts positively rated SINERGIA characteristics. At least one of the evaluated metrics of each exercise presented significant differences between both groups. Nevertheless, all metrics under study gave a better punctuation to the executions accomplished by experts (lower time, higher efficiency, fewer errors. . .) than to those made by novices. Conclusion SINERGIA laparoscopic virtual reality simulator is able to discriminate subjects according to their level of experience in laparoscopic surgery; therefore, it can be used within a training program as an assessment too

How Sugars Might Coordinate Chloroplast and Nuclear Gene Expression during Acclimation to High Light Intensities

The concept of retrograde control of nuclear gene expression assumes the generation of signals inside the chloroplasts, which are either released from or sensed inside of the organelle. In both cases, downstream signaling pathways lead eventually to a differential regulation of nuclear gene expression and the production of proteins required in the chloroplast. This concept appears reasonable as the majority of the over 3000 predicted plastidial proteins are encoded by nuclear genes. Hence, the nucleus needs information on the status of the chloroplasts, such as during acclimation responses, which trigger massive changes in the protein composition of the thylakoid membrane and in the stroma. Here, we propose an additional control mechanism of nuclear-and plastome-encoded photosynthesis genes, taking advantage of pathways involved in sugar-or hormonal signaling. Sugars are major end products of photosynthesis and their contents respond very sensitively to changes in light intensities. Based on recent findings, we ask the question as to whether the carbohydrate status outside the chloroplast can be directly sensed within the chloroplast stroma. Sugars might synchronize the responsiveness of both genomes and thereby help to coordinate the expression of plastome- and nuclear-encoded photosynthesis genes in concert with other, more specific retrograde signals

The essential role of sugar metabolism in the acclimation response of Arabidopsis thaliana to high light intensities

Schmitz J, Heinrichs L, Scossa F, et al. The essential role of sugar metabolism in the acclimation response of Arabidopsis thaliana to high light intensities. Journal of Experimental Botany. 2014;65(6):1619-1636.Retrograde signals from chloroplasts are thought to control the expression of nuclear genes associated with plastidial processes such as acclimation to varying light conditions. Arabidopsis mutants altered in the day and night path of photoassimilate export from the chloroplasts served as tools to study the involvement of carbohydrates in high light (HL) acclimation. A double mutant impaired in the triose phosphate/phosphate translocator (TPT) and ADP-glucose pyrophosphorylase (AGPase) (adg1-1/tpt-2) exhibits a HL-dependent depletion in endogenous carbohydrates combined with a severe growth and photosynthesis phenotype. The acclimation response of mutant and wild-type plants has been assessed in time series after transfer from low light (LL) to HL by analysing photosynthetic performance, carbohydrates, MgProtoIX (a chlorophyll precursor), and the ascorbate/glutathione redox system, combined with microarray-based transcriptomic and GC-MS-based metabolomic approaches. The data indicate that the accumulation of soluble carbohydrates (predominantly glucose) acts as a short-term response to HL exposure in both mutant and wild-type plants. Only if carbohydrates are depleted in the long term (e.g. after 2 d) is the acclimation response impaired, as observed in the adg1-1/tpt-2 double mutant. Furthermore, meta-analyses conducted with in-house and publicly available microarray data suggest that, in the long term, reactive oxygen species such as H2O2 can replace carbohydrates as signals. Moreover, a cross-talk exists between genes associated with the regulation of starch and lipid metabolism. The involvement of genes responding to phytohormones in HL acclimation appears to be less likely. Various candidate genes involved in retrograde control of nuclear gene expression emerged from the analyses of global gene expression

Congenital Hypothyroidism: A 2020-2021 Consensus Guidelines Update-An ENDO-European Reference Network Initiative Endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology.

BACKGROUND: An ENDO-European Reference Network (ERN) initiative was launched that was endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology with 22 participants from the ENDO-ERN and the two societies. The aim was to update the practice guidelines for the diagnosis and management of congenital hypothyroidism (CH). A systematic literature search was conducted to identify key articles on neonatal screening, diagnosis, and management of primary and central CH. The evidence-based guidelines were graded with the Grading of Recommendations, Assessment, Development and Evaluation system, describing both the strength of recommendations and the quality of evidence. In the absence of sufficient evidence, conclusions were based on expert opinion. SUMMARY: The recommendations include the various neonatal screening approaches for CH as well as the etiology (also genetics), diagnostics, treatment, and prognosis of both primary and central CH. When CH is diagnosed, the expert panel recommends the immediate start of correctly dosed levothyroxine treatment and frequent follow-up including laboratory testing to keep thyroid hormone levels in their target ranges, timely assessment of the need to continue treatment, attention for neurodevelopment and neurosensory functions, and, if necessary, consulting other health professionals, and education of the child and family about CH. Harmonization of diagnostics, treatment, and follow-up will optimize patient outcomes. Lastly, all individuals with CH are entitled to a well-planned transition of care from pediatrics to adult medicine. CONCLUSIONS: This consensus guidelines update should be used to further optimize detection, diagnosis, treatment, and follow-up of children with all forms of CH in the light of the most recent evidence. It should be helpful in convincing health authorities of the benefits of neonatal screening for CH. Further epidemiological and experimental studies are needed to understand the increased incidence of this condition

How to improve the adoption, performance and sustainability of ecological farming

This deliverable D7.6 of the LIFT project is the final scientific deliverable of the project that was carried out during four years from May 2018 till April 2022. The deliverable summarises the methodologies used and the key results for the main research activities that were carried out in LIFT: definition of ecological agriculture; adoption of ecological approaches; farm performance of ecological agriculture; territorial sustainability of ecological agriculture; trade-offs and synergies across sustainability dimensions and scales; impact of policies; role of stakeholders. Recommendations in terms of policies, data and research needs, are then provided.</p

Chronic and Acute Intranasal Oxytocin Produce Divergent Social Effects in Mice

Intranasal administration of oxytocin (OXT) might be a promising new adjunctive therapy for mental disorders characterized by social behavioral alterations such as autism and schizophrenia. Despite promising initial studies in humans, it is not yet clear the specificity of the behavioral effects induced by chronic intranasal OXT and if chronic intranasal OXT could have different effects compared with single administration. This is critical for the aforementioned chronic mental disorders that might potentially involve life-long treatments. As a first step to address these issues, here we report that chronic intranasal OXT treatment in wild-type C57BL/6J adult mice produced a selective reduction of social behaviors concomitant to a reduction of the OXT receptors throughout the brain. Conversely, acute intranasal OXT treatment produced partial increases in social behaviors towards opposite-sex novel-stimulus female mice, while on the other hand, it decreased social exploration of same-sex novel stimulus male mice, without affecting social behavior towards familiar stimulus male mice. Finally, prolonged exposure to intranasal OXT treatments did not alter, in wild-type animals, parameters of general health such as body weight, locomotor activity, olfactory and auditory functions, nor parameters of memory and sensorimotor gating abilities. These results indicate that a prolonged over-stimulation of a 'healthy' oxytocinergic brain system, with no inherent deficits in social interaction and normal endogenous levels of OXT, results in specific detrimental effects in social behaviors