Effects of Grassland Management on Herbage Lipid Composition and Consequences for Fatty Acids in Milk

Herbage provides bulk feed and is the basis for ruminant nutrition. Herbage lipids, especially C18:3, are a major source of beneficial fatty acids (FA) in milk. These desired FA are unsaturated FA such as CLA (conjugated linoleic acid), especially the isomer rumenic acid, and also vaccenic acid, both trans omega-7 FA (Ellen & Elgersma, 2004). As information on lipids in forages is scarce, effects were studied of N application level and regrowth period on the lipid concentration and FA composition of perennial ryegrass (Lolium perenne L.), the most important forage in temperate climate zones. A linear relation had previously been found between C18:3 intake of cows stall-fed with fresh grass and the amount of omega-7 FA in milk (Elgersma et al., 2003)

The role of the C8 proton of ATP in the regulation of phosphoryl transfer within kinases and synthetases

<p>Abstract</p> <p>Background</p> <p>The kinome comprises functionally diverse enzymes, with the current classification indicating very little about the extent of conserved regulatory mechanisms associated with phosphoryl transfer. The apparent <it>K</it>_mof the kinases ranges from less than 0.4 μM to in excess of 1000 μM for ATP. It is not known how this diverse range of enzymes mechanistically achieves the regulation of catalysis via an affinity range for ATP varying by three-orders of magnitude.</p> <p>Results</p> <p>We have demonstrated a previously undiscovered mechanism in kinase and synthetase enzymes where the overall rate of reaction is regulated via the C8-H of ATP. Using ATP deuterated at the C8 position (C8D-ATP) as a molecular probe it was shown that the C8-H plays a direct role in the regulation of the overall rate of reaction in a range of kinase and synthetase enzymes. Using comparative studies on the effect of the concentration of ATP and C8D-ATP on the activity of the enzymes we demonstrated that not only did C8D-ATP give a kinetic isotope effect (KIE) but the KIE's obtained are clearly not secondary KIE effects as the magnitude of the KIE in all cases was at least 2 fold and in most cases in excess of 7 fold.</p> <p>Conclusions</p> <p>Kinase and synthetase enzymes utilise C8D-ATP in preference to non-deuterated ATP. The KIE obtained at low ATP concentrations is clearly a primary KIE demonstrating strong evidence that the bond to the isotopically substituted hydrogen is being broken. The effect of the ATP concentration profile on the KIE was used to develop a model whereby the C8H of ATP plays a role in the overall regulation of phosphoryl transfer. This role of the C8H of ATP in the regulation of substrate binding appears to have been conserved in all kinase and synthetase enzymes as one of the mechanisms associated with binding of ATP. The induction of the C8H to be labile by active site residues coordinated to the ATP purine ring may play a significant role in explaining the broad range of <it>K</it>_massociated with kinase enzymes.</p

Examining the added value of the use of an experiment design tool among secondary students when experimenting with a virtual lab

International audienc

A good excuse for skipping the test: electrical storm in a teenager

We describe the case of a teenager with a structurally normal heart that presented with torsades de pointes and cardiac arrest. He had a history of epilepsy in childhood, mild cognitive impairment and cognitive visual dysfunction. The baseline electrocardiogram had prominent J waves and a marked early repolarization pattern in all the leads, with normal QT interval. We discuss the differential diagnosis for this interesting case, as well as the patient's management.info:eu-repo/semantics/publishedVersio

A importância do potássio e da alimentação na regulação da pressão arterial

Publicação no âmbito do Programa Nacional para a Promoção da Alimentação Saudável da DGS

Sinonasal adenocarcinomas: experience of Lisbon Oncology Institute between 2000 and 2014

Objetivos: Analisar dados demográficos, apresentação clínica, fatores de risco, opções terapêuticas e sobrevida de doentes com adenocarcinoma nasossinusal. Material e Métodos: Estudo retrospetivo de doentes com Adenocarcinoma Nasossinusal tratados entre 2000 e 2014, no IPOFGL. Resultados: Identificamos 33 doentes com diagnóstico de Adenocarcinoma. A idade média foi de 65.6 anos. A terapêutica mais comum foi cirurgia com radioterapia adjuvante. A sobrevida global e livre de doença aos 3 anos foi de 57.6% e 40.5%. A invasão do seio esfenoidal (p=0.038) e da base do crânio (p=0.003) influenciaram a sobrevida global. O desenvolvimento de metástases à distância teve impacto sobre a sobrevida livre de doença (p=0.01). Conclusões: Os Adenocarcinomas são tumores raros. A excisão da lesão toma um papel determinante no tratamento dos doentes. Na nossa amostra, a invasão do seio esfenoidal, da base do crânio e o desenvolvimento de metástases à distância estão associados a um pior prognóstico.Objective: To analyze treatment outcomes, including overall and disease-free survival rates, of patients with sinonasal adenocarcinomas. Methods: Retrospective study of patients with sinonasal adenocarcinoma treated in IPOFGL between 2000 and 2014. Results: We identified 33 patients; 17 were women and 16 men. Average age at diagnosis was 65.6 years and median follow-up was 39 months. Ethmoid sinus was the most frequent location; 51% presented at AJCC stage IV. Surgery with adjuvant radiotherapy was used in 70%. Overall survival at 36 months was 57.6%, with 40.5% disease-free survival. Recurrence was caused by local failure in majority of cases. Survival was decreased significantly in patients with sphenoid sinus involvement (p=0.038), skull base invasion (p=0.003) and recurrence metastatic disease (p<0.05). Conclusions: Complete surgical removal with postoperative radiotherapy remains the standard treatment modality. Sphenoid sinus and skull base invasion, and development of distant metastasis portend for poor prognosis

Influence of passage number on the impact of the secretome of adipose tissue stem cells on neural survival, neurodifferentiation and axonal growth

Mesenchymal stem cells (MSCs), and within them adipose tissue derived stem cells (ASCs), have been shown to have therapeutic effects on central nervous system (CNS) cell populations. Such effects have been mostly attributed to soluble factors, as well as vesicles, present in their secretome. Yet, little is known about the impact that MSC passaging might have in the secretion therapeutic profile. Our aim was to show how human ASCs (hASCs) passage number influences the effect of their secretome in neuronal survival, differentiation and axonal growth. For this purpose, post-natal rat hippocampal primary cultures, human neural progenitor cell (hNPCs) cultures and dorsal root ganglia (DRGs) explants were incubated with secretome, collected as conditioned media (CM), obtained from hASCs in P3, P6, P9 and P12. Results showed no differences when comparing percentages of MAP-2 positive cells (a mature neuronal marker) in neuronal cultures or hNPCs, after incubation with hASCs secretome from different passages. The same was observed regarding DRG neurite outgrowth. In order to characterize the secretomes obtained from different passages, a proteomic analysis was performed, revealing that its composition did not vary significantly with passage number P3 to P12. Results allowed us to identify several key proteins, such as pigment epithelium derived factor (PEDF), DJ-1, interleucin-6 (IL-6) and galectin, all of which have already proven to play neuroprotective and neurodifferentiating roles. Proteins that promote neurite outgrowth were also found present, such as semaphorin 7A and glypican-1. We conclude that cellular passaging does not influence significantly hASCs's secretome properties especially their ability to support post-natal neuronal survival, induce neurodifferentiation and promote axonal growth.Prémios Santa Casa Neurociências - Prize Melo e Castro for Spinal Cord Injury Research (MC-17-2013 and MC-04-2017), Canada Research Chair in Biomedical Engineering (LAB), Northern Portugal Regional Operational Programme (NORTE 2020),, European Regional Development Fund (FEDER), Competitiveness Factors Operational Programme (COMPETE), National Mass Spectrometry Network (RNEM)info:eu-repo/semantics/publishedVersio

Assessing chronic wasting disease risk in Portugal

info:eu-repo/semantics/publishedVersio