Nitrogen recycling from the xylem in rice leaves: dependence upon metabolism and associated changes in xylem hydraulics

Measurements of amino acids in the guttation fluid and in the xylem exudates of cut leaves from intact plants provide evidence of the remarkable efficiency with which these nitrogenous compounds are reabsorbed from the xylem sap. This could be achieved by mechanisms involving intercellular transport and/or metabolism. Developmental changes in transcripts and protein showed that transcripts for phosphoenolpyruvate carboxykinase (PEPCK) increased from the base to the leaf tip, and were markedly increased by supplying asparagine. Supplying amino acids also increased the amounts of protein of PEPCK and, to a lesser extent, of pyruvate, Pi dikinase. PEPCK is present in the hydathodes, stomata and vascular parenchyma of rice leaves. Evidence for the role of PEPCK was obtained by using 3-mercaptopicolinic acid (MPA), a specific inhibitor of PEPCK, and by using an activation-tagged rice line that had an increase in PEPCK activity, to show that activation of PEPCK resulted in a decrease in N in the guttation fluid and that treatment by MPA resulted in an increase in amino acids in the guttation fluid and xylem sap towards the leaf tip. Furthermore, increasing PEPCK activity decreased the amount of guttation fluid, whereas decreasing PEPCK activity increased the amount of xylem sap or guttation fluid towards the leaf tip. The findings suggest the following hypotheses: (i) both metabolism and transport are involved in xylem recycling and (ii) excess N is the signal involved in modulating xylem hydraulics, perhaps via nutrient regulation of water-transporting aquaporins. Water relations and vascular metabolism and transport are thus intimately linked

Autocrine prolactin promotes prostate cancer cell growth via Janus kinase-2-signal transducer and activator of transcription-5a/b signaling pathway.

The molecular mechanisms that promote progression of localized prostate cancer to hormone-refractory and disseminated disease are poorly understood. Prolactin (Prl) is a local growth factor produced in high-grade prostate cancer, and exogenously added Prl in tissue or explant cultures of normal and malignant prostate is a strong mitogen and survival factor for prostate epithelium. The key signaling proteins that mediate the biological effects of Prl in prostate cancer are Signal Transducer and Activator of Transcription (Stat)-5a/5b via activation of Janus kinase-2. Importantly, inhibition of Stat5a/b in prostate cancer cells induces apoptotic death. Using a specific Prl receptor antagonist (Delta1-9G129R-hPRL), we demonstrate here for the first time that autocrine Prl in androgen-independent human prostate cancer cells promotes cell viability via Stat5 signaling pathway. Furthermore, we examined a unique clinical material of human hormone refractory prostate cancers and metastases and show that autocrine Prl is expressed in 54% of hormone-refractory clinical human prostate cancers and 62% prostate cancer metastases. Finally, we demonstrate that autocrine Prl is expressed from both the proximal and distal promoters of the Prl gene in clinical human prostate cancers and in vivo and in vitro human prostate cancer models, independently of pituitary transcription factor-1 (Pit-1). Collectively, the data provide novel evidence for the concept that autocrine Prl signaling pathway is involved in growth of hormone-refractory and metastatic prostate cancer. The study also provides support for the use of Prl receptor antagonists or other therapeutic strategies to block the Prl-Janus kinase-2-Stat5 signaling pathway in advanced prostate cancer

Intestinal gluconeogenesis and glucose transport according to body fuel availability in rats

Intestinal hexose absorption and gluconeogenesis have been studied in relation to refeeding after two different fasting phases: a long period of protein sparing during which energy expenditure is derived from lipid oxidation (phase II), and a later phase characterized by a rise in plasma corticosterone triggering protein catabolism (phase III). Such a switch in body fuel uses, leading to changes in body reserves and gluconeogenic precursors, could modulate intestinal gluconeogenesis and glucose transport. The gene and protein levels, and the cellular localization of the sodium-glucose cotransporter SGLT1, and of GLUT5 and GLUT2, as well as that of the key gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (Glc6Pase) were measured. PEPCK and Glc6Pase activities were also determined. In phase III fasted rats, SGLT1 was up-regulated and intestinal glucose uptake rates were higher than in phase II fasted and fed rats. PEPCK and Glc6Pase mRNA, protein levels and activities also increased in phase III. GLUT5 and GLUT2 were down-regulated throughout the fast, but increased after refeeding, with GLUT2 recruited to the apical membrane. The increase in SGLT1 expression during phase III may allow glucose absorption at low concentrations as soon as food is available. Furthermore, an increased epithelial permeability due to fasting may induce a paracellular movement of glucose. In the absence of intestinal GLUT2 during fasting, Glc6Pase could be involved in glucose release to the bloodstream via membrane trafficking. Finally, refeeding triggered GLUT2 and GLUT5 synthesis and apical recruitment of GLUT2, to absorb larger amounts of hexoses

What "best practice" could be in Palliative Care: an analysis of statements on practice and ethics expressed by the main Health Organizations

<p>Abstract</p> <p>Background</p> <p>In palliative care it would be necessary to refer to a model. Nevertheless it seems that there are no official statements which state and describe that model. We carried out an analysis of the statements on practice and ethics of palliative care expressed by the main health organizations to show which dimensions of end-of-life care are taken into consideration.</p> <p>Methods</p> <p>The official documents by the most representative health organisations committed to the definition of policies and guidelines for palliative and end-of-life care had been considered. The documents were analysed through a framework of the components of end-of-life care derived from literature, which was composed of 4 main "areas" and of 12 "sub-areas".</p> <p>Results</p> <p>Overall, 34 organizations were identified, 7 international organisations, and 27 organisations operating on the national level in four different countries (Australia, Canada, UK and United States). Up to 56 documents were selected and analysed. Most of them (38) are position statements. Relevant quotations from the documents were presented by "areas" and "sub-areas". In general, the "sub-areas" of symptoms control as well as those referring to relational and social issues are more widely covered by the documents than the "sub-areas" related to "preparation" and to "existential condition". Indeed, the consistency of end-of-life choices with the patient's wishes, as well as completion and meaningfulness at the end of life is given only a minor relevance.</p> <p>Conclusions</p> <p>An integrated model of the best palliative care practice is generally lacking in the documents. It might be argued that the lack of a fixed and coherent model is due to the relevance of unavoidable context issues in palliative care, such as specific cultural settings, patient-centred variables, and family specificity. The implication is that palliative care staff have continuously to adapt their model of caring to the specific needs and values of each patient, more than applying a fixed, although maybe comprehensive, care model.</p

Functional Outcomes of Children on Discharge from a Paediatric Intensive Care Unit

A research report submitted in fulfillment of the requirements for the Master of Science in Physiotherapy, in the Faculty of Health Sciences, School of Therapeutic Sciences, University of the Witwatersrand, Johannesburg, 2024Background Paediatric critical care is a constantly evolving field of health care and has changed considerably over the past two decades. Improved care and paediatric intensive care unit (PICU) protocols have resulted in increased survival rates of patients presenting to PICU. However, this also means that the number of surviving patients with long term functional impairments has increased. Research acknowledges that children are at risk of recurrent serious acute illness and more PICU admissions, yet how children and their families recover after surviving a critical illness is poorly understood. Objective This cross-sectional study aimed to assess the functional outcomes of paediatric patients on discharge from a private hospital PICU using the Functional Status Scale (FSS). The objectives included describing demographic characteristics and clinical characteristics of participants admitted to a particular PICU in Gauteng, South Africa. Secondly to establish functional outcomes in six domains – mental status, sensory, motor function, communication, feeding, and respiratory function, at the time of discharge from PICU, using the FSS and furthermore, to investigate the association between admission diagnosis, age, sex, length of stay (LOS), duration of ventilation of participants and functional outcomes, at the time of PICU discharge. Methods Conducted between May 2023 and December 2023, this study included paediatric patients aged 1 month to 13 years, where the appropriate consent and assent was obtained. All patients were admitted to a private hospital PICU, in Gauteng South Africa, for more than 24 hours, to meet the inclusion criteria. The FSS (total score = 30; sub scores per domain = 5), which assesses functional status across six domains, was administered on the day of discharge from PICU. Data capturing was conducted by the primary investigator and statistical analysis was done by a senior data scientist using MATLAB R2024a and Spearman correlation co-efficient to draw correlations between variables. using Spearman correlation co-efficient to draw correlations between variables. iv Results The cohort consisted of 28 participants that completed the study. Based on the findings of this research it was concluded that, within this cohort the median (IQR) age of the participants was 24 (14-72) months old and the median (IQR) LOS was 21 (8-32) days. The sample was equally distributed for males (50%) and females (50%). Most common causes for admission were either respiratory (n =11; 39.3%) or neurological (n=11;39.3%) in nature and this was the first PICU admission for 64% (n = 18) of cohort. The FSS mean and median overall score was eight (8/30). The highest mean scores were noted in the mental status and motor function domains and 36% (n = 10) of participants had a score of more than or equal to nine indicating ‘mild’ to ‘moderate’ dysfunction. Common trends within the correlations, included that longer duration of ventilation results in higher FSS mental status scores (r =0.74; p = <0.01; worse dysfunction); longer duration of ventilation results in higher FSS scores for the respiratory domain (r = 0.74; p = 0.0005; worse dysfunction) and lastly, the longer PICU LOS the higher the FFS motor function scores (r = 0.61; p = 0.0007; worse dysfunction). Conclusion Children admitted to this particular PICU are most likely to be younger than or equal to 24 months old and have a longer LOS (median = 21 days). Evaluation of functional status indicated higher scores in the mental status and motor function domains of the FSS and an overall score falling within either the normal or mild dysfunction category. Participants with greater functional impairments had longer PICU stays and longer duration of mechanical ventilation. The FSS provided a rapid and effective assessment of functional status in PICU patients. The observed correlations suggest that prolonged duration of ventilation and extended PICU stay are associated with increased functional dysfunction, particularly in mental status, respiratory and motor domains. This is important to consider when re-evaluating PICU protocols such as ventilation weaning protocols and discharge criteria. The FSS’s ability to quickly assess multiple domains is a valuable tool for evaluating post-PICU functional status, to allow for early identification of patients who are at high risk for developing medium-to long -term disability.MM202

Les Allergènes fongiques au domicile et les conseils à l'officine

LYON1-BU Santé (693882101) / SudocSudocFranceF