Creatine kinase in energy metabolic signaling in muscle

There has been much debate on the mechanism of regulation of mitochondrial ATP synthesis to balance ATP consumption during changing cardiac workloads. A key role of creatine kinase (CK) isoenzymes in this regulation of oxidative phosphorylation and in intracellular energy transport had been proposed, but has in the mean time been disputed for many years. It was hypothesized that high-energy phosphoryl groups are obligatorily transferred via CK; this is termed the phosphocreatine shuttle. The other important role ascribed to the CK system is its ability to buffer ADP concentration in cytosol near sites of ATP hydrolysis. 

Almost all of the experiments to determine the role of CK had been done in the steady state, but recently the dynamic response of oxidative phosphorylation to quick changes in
cytosolic ATP hydrolysis has been assessed at various levels of inhibition of CK. Steady state models of CK function in energy transfer existed but were unable to explain the dynamic response with CK inhibited.

The aim of this study was to explain the mode of functioning of the CK system in heart, and in particular the role of different CK isoenzymes in the dynamic response to workload steps. For this purpose we used a mathematical model of cardiac muscle cell energy metabolism containing the kinetics of the key processes of energy production, consumption and transfer pathways. The model underscores that CK plays indeed a dual role in the cardiac cells. The buffering role of CK system is due to the activity of myofibrillar CK (MMCK) while the energy transfer role depends on the activity of mitochondrial CK (MiCK). We propose that this may lead to the differences in regulation mechanisms and energy transfer modes in species with relatively low MiCK activity such as rabbit in comparison with species with high MiCK activity such as rat.

The model needed modification to explain the new type of experimental data on the dynamic response of the mitochondria. We submit that building a Virtual Muscle Cell is not possible without continuous experimental tests to improve the model. In close interaction with experiments we are developing a model for muscle energy metabolism and transport mediated by the creatine kinase isoforms which now already can explain many different types of experiments

Unilateral versus bilateral upper limb training after stroke: The upper limb training after stroke clinical trial

This article is available open access through the publisher’s website at the link below. Copyright © 2013 American Heart Association, Inc.Background and Purpose — Unilateral and bilateral training protocols for upper limb rehabilitation after stroke represent conceptually contrasting approaches with the same ultimate goal. In a randomized controlled trial, we compared the merits of modified constraint-induced movement therapy, modified bilateral arm training with rhythmic auditory cueing, and a dose-matched conventional treatment. Modified constraint-induced movement therapy and modified bilateral arm training with rhythmic auditory cueing targeted wrist and finger extensors, given their importance for functional recovery. We hypothesized that modified constraint-induced movement therapy and modified bilateral arm training with rhythmic auditory cueing are superior to dose-matched conventional treatment. Methods — Sixty patients, between 1 to 6 months after stroke, were randomized over 3 intervention groups. The primary outcome measure was the Action Research Arm test, which was conducted before, directly after, and 6 weeks after intervention. Results — Although all groups demonstrated significant improvement on the Action Research Arm test after intervention, which persisted at 6 weeks follow-up, no significant differences in change scores on the Action Research Arm test were found between groups postintervention and at follow-up. Conclusions — Modified constraint-induced movement therapy and modified bilateral arm training with rhythmic auditory cueing are not superior to dose-matched conventional treatment or each other in improving upper limb motor function 1 to 6 months after stroke. Clinical Trial Registration — URL: http://www.trialregister.nl. Unique identifier: NTR1665

Rubus aetnicus Cupani ex Weston and R. canescens DC. (Rosaceae): an analysis

Beek (2016) argued that Rubus aetnicus Cupani ex Weston was the correct name of the taxon that was then called R. canescens DC., and which was previously known as R. tomentosus Borkh. Moreover, R. canescens was stated to be not identical with R. aetnicus, but rather a form of R. × collinus DC. Matzke-Hajek (2016) raised objections to both statements. Therefore, the aim of this study was to thoroughly analyse both names and support this analysis with field work at the type localities and by DNA data. Despite the correspondence at the investigated conservative DNA loci, the investigation showed that the two species are morphologically different and must be conceived as separate taxa. According to the rules of the ICN, R. aetnicus, as the earliest available legitimate name, must be accepted as the correct name for R. tomentosus auct. non Borkh. There is no reason not to use the name R. aetnicus, which has not been commonly used until now. It is unambiguous, while any other name could cause confusion if it would be conserved. Other scientific names clarified in this study are R. aetnaeus Tornab. (= R. ulmifolius Schott), R. aetnensis Tornab. (= R. aetnicus) and R. argenteus Gmel

How to assist probationers with debt problems during supervision?:A qualitative study into the experiences of both probation officers and clients

Little research exists on what works in the supervision of offenders with debt problems. This qualitative study aims to provide insight into the barriers probation officers and clients experience during supervision regarding debt and the support that clients need. Interviews were conducted with 33 Dutch probation officers and 16 clients. The results show that debt often negatively influences clients’ lives and hinders their resocialization. Probation officers lack effective methods to support clients with debt problems. To adequately help clients with debt problems, probation officers should obtain more knowledge about effective interventions and collaborate more closely with debt specialists from the probation supervision outset

Waiboerhoeve Proefbedrijf Varkens officieel geopend

Op 11 oktober 2001 opende LNV-minister Brinkhorst officieel het nieuwe proefbedrijf varkens van PV en ID in Lelystad

Heat transmission of a reference and practical container under subtropical conditions

Meting van de koelcapaciteit van een container onder Zuiditaliaanse klimaatsomstandighede