185 research outputs found
Metabolic adaptations in skeletal muscle after 84 days of bed rest with and without concurrent flywheel resistance exercise
As metabolic changes in human skeletal muscle after long-term (simulated) spaceflight are not well understood, this study examined the effects of long-term microgravity, with and without concurrent resistance exercise, on skeletal muscle oxidative and glycolytic capacity. Twenty-one men were subjected to 84 days head-down tilt bed rest with (BRE; n 9) or without (BR; n 12) concurrent flywheel resistance exercise. Activity and gene expression of glycogen synthase, glycogen phosphorylase (GPh), hexokinase, phosphofructokinase-1 (PFK-1), and citrate synthase (CS), as well as gene expression of succinate dehydrogenase (SDH), vascular endothelial growth factor (VEFG), peroxisome proliferator-activated receptor gamma coactivator- 1 (PGC-1 ), and myostatin, were analyzed in samples from m.vastus lateralis collected before and after bed rest. Activity and gene expression of enzymes controlling oxidative metabolism (CS, SDH) decreased in BR but were partially maintained in BRE. Activity of enzymes regulating anaerobic glycolysis (GPh, PFK-1) was unchanged in BR. Resistance exercise increased the activity of GPh. PGC-1 and VEGF expression decreased in both BR and BRE. Myostatin increased in BR but decreased in BRE after bed rest. The analyses of these unique samples indicate that long-term microgravity induces marked alterations in the oxidative, but not the glycolytic, energy system. The proposed flywheel resistance exercise was effective in counteracting some of the metabolic alterations triggered by 84-day bed rest. Given the disparity between gene expression vs. enzyme activity in several key metabolic markers, posttranscriptional mechanisms should be explored to fully evaluate metabolic adaptations to long-term microgravity with/without exercise countermeasures in human skeletal muscle
an analysis of the ClinicalTrials.gov database
Background To evaluate the current status of prospective interventional
clinical trials that includes brachytherapy (BT) procedures. Methods The
records of 175,538 (100 %) clinical trials registered at ClinicalTrials.gov
were downloaded on September 2014 and a database was established. Trials using
BT as an intervention were identified for further analyses. The selected
trials were manually categorized according to indication(s), BT source,
applied dose rate, primary sponsor type, location, protocol initiator and
funding source. We analyzed trials across 8 available trial protocol elements
registered within the database. Results In total 245 clinical trials were
identified, 147 with BT as primary investigated treatment modality and 98 that
included BT as an optional treatment component or as part of the standard
treatment. Academic centers were the most frequent protocol initiators in
trials where BT was the primary investigational treatment modality (p < 0.01).
High dose rate (HDR) BT was the most frequently investigated type of BT dose
rate (46.3 %) followed by low dose rate (LDR) (42.0 %). Prostate was the most
frequently investigated tumor entity in trials with BT as the primary
treatment modality (40.1 %) followed by breast cancer (17.0 %). BT was rarely
the primary investigated treatment modality for cervical cancer (6.8 %).
Conclusion Most clinical trials using BT are predominantly in early phases,
investigator-initiated and with low accrual numbers. Current investigational
activities that include BT mainly focus on prostate and breast cancers.
Important questions concerning the optimal usage of BT will not be answered in
the near future
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Changes in Day/Night Activity in the 6-OHDA-Induced Experimental Model of Parkinson's Disease: Exploring Prodromal Biomarkers.
The search for experimental models mimicking an early stage of Parkinson's disease (PD) before motor manifestations is fundamental in order to explore early signs and get a better prognosis. Interestingly, our previous studies have indicated that 6-hydroxydopamine (6-OHDA) is a suitable model to induce an early degeneration of the nigrostriatal system without any gross motor impairment. Considering our previous findings, we aim to implement a novel system to monitor rats after intrastriatal injection of 6-OHDA to detect and analyze physiological changes underlying prodromal PD. Twenty male Sprague-Dawley rats were unilaterally injected with 6-OHDA (n = 10) or saline solution (n = 10) into the right striatum and placed in enriched environment cages where the activity was monitored. After 2 weeks, the amphetamine test was performed before the sacrifice. Immunohistochemistry was developed for the morphological evaluation and western blot analysis to assess molecular changes. Home-cage monitoring revealed behavioral changes in response to 6-OHDA administration including significant hyperactivity and hypoactivity during the light and dark phase, respectively, turning out in a change of the circadian timing. A preclinical stage of PD was functionally confirmed with the amphetamine test. Moreover, the loss of tyrosine hydroxylase expression was significantly correlated with the motor results, and 6-OHDA induced early proapoptotic events. Our findings provide evidence for a novel prodromal 6-OHDA model following a customized monitoring system that could give insights to detect non-motor deficits and molecular targets to test neuroprotective/neurorestorative agents
Endothelin‐1 response to whole‐body vibration in obese and normal weight individuals
Upregulation of endothelin‐1 (ET‐1) is the hallmark of various cardiovascular diseases (CVD). The purpose of the present study was to assess the ET‐1 response to an acute bout of whole‐body vibration (WBV) in humans and to determine the role of adiposity. Twenty‐two participants volunteered for the study; they were grouped into overweight/obese [(OW/OB): n = 11, Age: 33 ± 4 years, Body mass index (BMI): 35 ± 10 kg/m(2)] or normal weight [(NW): n = 11, Age: 28 ± 7 years, BMI: 21 ± 2 kg/m(2)]. Participants engaged in 10 cycles of WBV exercise (1 cycle = 1 min WBV followed by 30 s of rest). Blood samples were analyzed for ET‐1 pre‐WBV (PRE), immediately post (POST), 1 h (1H), 3 h (3H), and 24 h (24H) post‐WBV. There was a significant time main effect of WBV on circulating ET‐1 (F = 12.5, p < 0.001); however, the ET‐1 response was similar (F = 0.180, p = 0.677) between groups. Specifically, compared to PRE, a significant increase in ET‐1 was observed at 1H (p = 0.017) and 3H (p = 0.025). In addition, concentrations of ET‐1 were significantly lower at 24H compared to PRE (p = 0.019), 1H (p < 0.001), and 3H (p < 0.001). Maximal oxygen uptake during WBV was similar between the two groups. Acute WBV resulted in an initial rise in ET‐1, followed by a significantly lower ET‐1 at 24H in both groups. Findings support the utility of routine WBV exercise to elicit a decrease in ET‐1 and improve CVD risk, similar to what has been reported with traditional modes of exercise
Activation of Ventral Tegmental Area 5-HT2C Receptors Reduces Incentive Motivation
FUNDING AND DISCLOSURE The research was funded by Wellcome Trust (WT098012) to LKH; and National Institute of Health (DK056731) and the Marilyn H. Vincent Foundation to MGM. The University of Michigan Transgenic Core facility is partially supported by the NIH-funded University of Michigan Center for Gastrointestinal Research (DK034933). The remaining authors declare no conflict of interest. ACKNOWLEDGMENTS We thank Dr Celine Cansell, Ms Raffaella Chianese and the staff of the Medical Research Facility for technical assistance. We thank Dr Vladimir Orduña for the scientific advice and technical assistance.Peer reviewedPublisher PD
Transfer of SCN1A to the brain of adolescent mouse model of Dravet syndrome improves epileptic, motor, and behavioral manifestations
Dravet syndrome is a genetic encephalopathy characterized by severe epilepsy combined with motor, cognitive, and behavioral abnormalities. Current antiepileptic drugs achieve only partial control of seizures and provide little benefit on the patient’s neurological development. In >80% of cases, the disease is caused by haploinsufficiency of the SCN1A gene, which encodes the alpha subunit of the Nav1.1 voltage-gated sodium channel. Novel therapies aim to restore SCN1A expression in order to address all disease manifestations. We provide evidence that a high-capacity adenoviral vector harboring the 6-kb SCN1A cDNA is feasible and able to express functional Nav1.1 in neurons. In vivo, the best biodistribution was observed after intracerebral injection in basal ganglia, cerebellum, and prefrontal cortex. SCN1A A1783V knockin mice received the vector at 5 weeks of age, when most neurological alterations were present. Animals were protected from sudden death, and the epileptic phenotype was attenuated. Improvement of motor performance and interaction with the environment was observed. In contrast, hyperactivity persisted, and the impact on cognitive tests was variable (success in novel object recognition and failure in Morris water maze tests). These results provide proof of concept for gene supplementation in Dravet syndrome and indicate new directions for improvement
Sl-EDGE: Network Slicing at the Edge
Network slicing of multi-access edge computing (MEC) resources is expected to
be a pivotal technology to the success of 5G networks and beyond. The key
challenge that sets MEC slicing apart from traditional resource allocation
problems is that edge nodes depend on tightly-intertwined and
strictly-constrained networking, computation and storage resources. Therefore,
instantiating MEC slices without incurring in resource over-provisioning is
hardly addressable with existing slicing algorithms. The main innovation of
this paper is Sl-EDGE, a unified MEC slicing framework that allows network
operators to instantiate heterogeneous slice services (e.g., video streaming,
caching, 5G network access) on edge devices. We first describe the architecture
and operations of Sl-EDGE, and then show that the problem of optimally
instantiating joint network-MEC slices is NP-hard. Thus, we propose
near-optimal algorithms that leverage key similarities among edge nodes and
resource virtualization to instantiate heterogeneous slices 7.5x faster and
within 0.25 of the optimum. We first assess the performance of our algorithms
through extensive numerical analysis, and show that Sl-EDGE instantiates slices
6x more efficiently then state-of-the-art MEC slicing algorithms. Furthermore,
experimental results on a 24-radio testbed with 9 smartphones demonstrate that
Sl-EDGE provides at once highly-efficient slicing of joint LTE connectivity,
video streaming over WiFi, and ffmpeg video transcoding
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