Purpose
Sprint interval training (SIT), involving brief intermittent bursts of vigorous exercise within a single training session, is a time-efficient way to improve cardiorespiratory fitness (CRF). ...It is unclear whether performing sprints spread throughout the day with much longer (≥ 1 h) recovery periods can similarly improve CRF, potentially allowing individuals to perform “sprint snacks” throughout the day to gain health benefits.
Methods
Healthy, young, inactive adults (~ 22 years, peak oxygen uptake VO
2
peak ~ 35 ml kg
− 1
min
− 1
) were randomly assigned to one of two groups and performed 18 training sessions over 6 wks. Sprint snacks (SS) involved 3 × 20-s ‘all out’ cycling bouts separated by 1–4-h rest (
n
= 12, 7 females). Traditional SIT involved 3 × 20-s bouts interspersed with 3-min rest within a 10-min training session (
n
= 16, 7 females). The primary outcome was CRF determined by a
V
O
2
peak test conducted before and after training. Secondary outcomes included a 150 kJ cycling time trial and exercise enjoyment.
Results
Absolute
V
O
2
peak increased by ~ 6% after SIT and ~ 4% for SS (main effect of time
P
= 0.002) with no difference between groups (group × time interaction,
P
= 0.52). 150 kJ time trial performance improved by ~ 13% in SIT and ~ 9% in SS (main effect of time,
P
< 0.001) with no difference between groups (group × time interaction,
P
= 0.36).
Conclusion
CRF was similarly increased by a protocol involving sprint snacks spread throughout the day and a traditional SIT protocol in which bouts were separated by short recovery periods within a single training session.
Metastasis is the leading cause of mortality in cancer patients. To migrate to distant sites, cancer cells would need to adapt their behaviour in response to different tissue environments. Thus, it ...is essential to study this process in models that can closely replicate the tumour microenvironment. Here, we evaluate the use of organotypic liver and brain slices to study cancer metastasis. Morphological and viability parameters of the slices were monitored daily over 3 days in culture to assess their stability as a realistic 3D tissue platform for in vitro metastatic assays. Using these slices, we evaluated the invasion of MDA-MB-231 breast cancer cells and of a subpopulation that was selected for increased motility. We show that the more aggressive invasion of the selected cells likely resulted not only from their lower stiffness, but also from their lower adhesion to the surrounding tissue. Different invasion patterns in the brain and liver slices were observed for both subpopulations. Cells migrated faster in the brain slices (with an amoeboid-like mode) compared to in the liver slices (where they migrated with mesenchymal or collective migration-like modes). Inhibition of the Ras/MAPK/ERK pathway increased cell stiffness and adhesion forces, which resulted in reduced invasiveness. These results illustrate the potential for organotypic tissue slices to more closely mimic in vivo conditions during cancer cell metastasis than most in vitro models.
•Liver and brain slices can be stable, realistic in vitro 3D models.•Cell stiffness and adhesion to the tissue play determinant roles in cellular invasion in 3D.•MEK inhibitors can lead to increased cell stiffness and adhesion forces, and consequently reduced cancer cell invasion.•MDA-MB-231 breast cancer cells migrate faster and deeper into brain tissue compared to liver tissue.
There are conflicting data regarding the prognostic value of syncope in patients with acute pulmonary embolism (APE).
We retrospectively reviewed data of 552 consecutive adults with computed ...tomography pulmonary angiogram-confirmed APE to determine the correlates and outcome of the occurrence of syncope at the time of presentation.
Among 552 subjects with APE (mean age 54years, 47% men), syncope occurred in 12.3% (68/552). Compared with subjects without syncope, those with syncope were more likely to have admission systolic blood pressure<90mmHg (odds ratio (OR) 5.788, P<0.001), and an oxygen saturation<88% on room air (OR 5.560, P<0.001), right ventricular dilation (OR 2.480, P=0.006), right ventricular hypokinesis (OR 2.288, P=0.018), require mechanical ventilation for respiratory failure (OR 3.152, P=0.014), and more likely to receive systemic thrombolysis (OR 4.722, P=0.008). On multivariate analysis, syncope on presentation was an independent predictor of a massive APE (OR 2.454, 95% CI 1.109–5.525, P=0.03) after adjusting for patients' age, sex, requirement of antibiotics throughout hospitalization, peak serum creatinine, admission oxygen saturation<88% and admission heart rate>100bpm. There was no difference in mortality in cases with APE with or without syncope (P=0.412).
Syncope at the onset of pulmonary embolization is a surrogate for submassive and massive APE but is not associated with higher in-hospital mortality.
Abstract only
In healthy individuals, sympathetic vasoconstriction is blunted in exercising muscles, contributing to the matching of blood flow with metabolic demand. This “functional sympatholysis” ...may be impaired in young obese adults due to greater sympathetic activation and reduced local vasodilatory capacity of both small and large arteries, but this remains poorly understood. We tested the hypothesis that functional sympatholysis is impaired in obese adults compared with lean counterparts. Participants were 13 lean (female=6; 26±1 yrs; 22.4±0.5 kg/m
2
) and 14 obese adults (female=7; 27±1 yrs; 32.6±0.6 kg/m
2
). Lower body negative pressure (LBNP −20 mmHg, 2 min), to evoke reflex‐mediated increases in sympathetic nerve activity, was performed at rest and during steady‐state dynamic handgrip exercise (HG, 30% maximal voluntary contraction; 50% duty cycle). Ultrasonography brachial diameter, forearm blood flow (FBF), forearm vascular conductance (FVC), and beat‐to‐beat cardiovascular variables mean arterial pressure (MAP), heart rate (HR), and cardiac index (CI) were obtained. FBF and FVC were normalized to lean forearm mass, and CI was cardiac output indexed to body surface area. No group differences were found at rest or during handgrip before LBNP for any variable. LBNP evoked similar decreases in FBF (−18.6±3.0% lean vs. −17.8±3.1% obese) and FVC (−16.6±3.1% lean vs. −14.9±3.1% obese) in the resting forearms of the lean and obese adults (
P
>0.05 for group). During HG, reductions in FBF (−1.7±3.8% lean vs. −2.0±2.3% obese) and FVC (1.2±4.3% lean vs. 0.1±2.5% obese) to LBNP were blunted in the exercising forearms of both groups (
P
>0.05 for group). In both lean and obese subjects, LBNP decreased MAP and CI at rest and during HG, but decreased brachial artery diameter and increased HR only during HG (all;
P
<0.05 for time effect). Our preliminary data suggests that functional sympatholysis is not impaired in young obese adults without comorbidities.
Support or Funding Information
This project is sponsored by the American Heart Association Predoctoral Fellowship (16PRE26430096).
Variable
Group
Rest
Rest with LBNP
30%MVC
30%MVC with LBNP
Brachial Artery Diameter (mm)
Lean
3.46±0.15
3.43±0.14
3.64±0.14
3.62±0.14
*
Obese
3.62±0.14
3.60±0.14
3.76±0.14
3.73±0.13
*
FBF (mL/min
*
100g tissue)
Lean
11±1
8±1
*
30±2
30±2
Obese
10±1
8±1
*
27±2
27±2
FVC (mL/min
*
100mmHg
*
100g tissue)
Lean
11±1
9±1
*
30±2
31±2
Obese
10±1
9±1
*
27±2
27±2
MAP (mmHg)
Lean
101±2
99±2
*
102±3
100±3
*
Obese
100±2
96±2
*
103±3
101±3
*
HR (bpm)
Lean
62±2
63±2
67±2
71±2
*
Obese
64±2
64±2
67±2
72±2
*
CI (L/min/m
2
)
Lean
3.3±0.2
3.0±0.2
*
3.7±0.2
3.3±0.2
*
Obese
3.0±0.2
2.7±0.2
*
3.2±0.2
3.0±0.2
*
Data are mean±SE.
P
<0.05, time effect.
To date, no medication has slowed the progression of Parkinson's disease (PD). Preclinical, epidemiological, and experimental data on humans all support many benefits of endurance exercise among ...persons with PD. The key question is whether there is a definitive additional benefit of exercising at high intensity, in terms of slowing disease progression, beyond the well-documented benefit of endurance training on a treadmill for fitness, gait, and functional mobility. This study will determine the efficacy of high-intensity endurance exercise as first-line therapy for persons diagnosed with PD within 3 years, and untreated with symptomatic therapy at baseline.
This is a multicenter, randomized, evaluator-blinded study of endurance exercise training. The exercise intervention will be delivered by treadmill at 2 doses over 18 months: moderate intensity (4 days/week for 30 min per session at 60-65% maximum heart rate) and high intensity (4 days/week for 30 min per session at 80-85% maximum heart rate). We will randomize 370 participants and follow them at multiple time points for 24 months. The primary outcome is the Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor score (Part III) with the primary analysis assessing the change in MDS-UPDRS motor score (Part III) over 12 months, or until initiation of symptomatic antiparkinsonian treatment if before 12 months. Secondary outcomes are striatal dopamine transporter binding, 6-min walk distance, number of daily steps, cognitive function, physical fitness, quality of life, time to initiate dopaminergic medication, circulating levels of C-reactive protein (CRP), and brain-derived neurotrophic factor (BDNF). Tertiary outcomes are walking stride length and turning velocity.
SPARX3 is a Phase 3 clinical trial designed to determine the efficacy of high-intensity, endurance treadmill exercise to slow the progression of PD as measured by the MDS-UPDRS motor score. Establishing whether high-intensity endurance treadmill exercise can slow the progression of PD would mark a significant breakthrough in treating PD. It would have a meaningful impact on the quality of life of people with PD, their caregivers and public health.
ClinicalTrials.gov NCT04284436 . Registered on February 25, 2020.
The impact of cytomegalovirus (CMV) serostatus (seropositive + or seronegative -) of the donor (D) and recipient (R) on mortality after allogeneic non-T cell-depleted stem cell transplantation (SCT) ...in the era of preemptive therapy was assessed among 1750 patients by means of multivariable Cox regression models. In an analysis that included only pre-SCT variables, D+/R+ and D+/R- patients had the highest risk for mortality. After neutropenia or the occurrence of CMV disease was controlled for, only D+/R- patients remained at a significantly higher risk for mortality. Mortality due to bacteremia or invasive fungal infection was higher among D+/R- (18.3%) than D-/R- (9.7%) patients (P < .001). Thus, CMV serostatus remains associated with mortality; neutropenia due to ganciclovir administration and CMV disease explain the association with mortality among seropositive recipients. However, in D+/R- subjects, mortality appears to be associated with bacterial and fungal infection, indicating a possible immunomodulatory effect of primary CMV infection that was undetected despite intensive monitoring.
There has been significant debate in the literature on technology-mediated training about the appropriate role of learner control. We define learner control as giving trainees the ability to make ...choices about how they proceed through the learning environment. We explore two perspectives. First, we consider learners’ stated preferences for the extent of control in the learning environment. Second, we analyze the actual online learning behaviors of 518 trainees in a Fortune 500 organization. We compare a measure of learner control preferences to the most commonly used framework of learner control that comprises five dimensions: pace of instruction, sequence of topics, specific content covered, amount of advice/feedback provided, and type of media. We also compare the dimensionality of learner behaviors to this framework and examine the relationship between learner preferences and learner behaviors. Results suggest that fewer dimensions can capture both learner preferences and behaviors than what the literature currently suggests. Specifically, media control aligned with both pace and content control. The relationship between stated learner control preferences and learner control behaviors was relatively weak. However, we found support for the recently identified dimension of scheduling control and suggest a new learner control dimension of performance control, consistent with the importance of practice retrieval for learning.
The future university Rothblatt, Sheldon; Morley, Louise; Wheelahan, Leesa ...
2012
Book
As universities increasingly engage with the world beyond the classroom and the campus, those who work within higher education are left to examine how the university's mission has changed. Official ...reviews and debates often forget to inquire into the purposes and responsibilities of universities, and how they are changing. Where these matters are addressed, they are rarely pursued in depth, and rarely go beyond current circumstances. Those who care about the university's role in society are left looking for a renewed sense of purpose regarding its goals and aspirations. The Future University explores new avenues opening up to universities and tackles fundamental issues facing their development. Contributors with interdisciplinary and international perspectives imagine ways to frame the university's future. They consider the history of the university, its current status as an active player in local governments, cultures, and markets, and where these trajectories may lead. What does it mean to be a university in the twenty-first century? What could the university become? What limitations do they face, and what opportunities might lie ahead? This volume in the International Studies in Higher Education series offers bold and imaginative possibilities. - INHALT: Barnett, Ronald: Introduction. - PART I: Emerging futures (Rothblatt, Sheldon: 1. The Future isn't Waiting. - Morley, Louise: 2. Imagining the University of the Future). - PART II: Global possibilities (Wheelahan, Leesa: 3. Accessing Knowledge in the University of the Future: Lessons from Australia. - Chen, Shuang-Ye; Lo, Leslie N.K.; 4. The Trajectory and Future of the Idea of the University in China. - Diaz Villa, Mario: 5. The Idea of the University in Latin America in the 21st Century. - Waghid, Yusef: 6. The Decline of the University in South Africa: Reconstituting the Place of Reason). - Part III: Ideas of the University (Standaert, Nicolas: 7. Towards a Networked University. - Kavanagh, Donncha: 8. The University as Fool. - Dall'Alba, Gloria: 9. Re-imagining the University: Developing a Capacity to Care. - Maxwell, Nicholas: 10. Creating a Better World: Towards the University of Wisdom). - PART IV: A University for Society (Nixon, Jon: 11. Universities and the Common Good. - Standish, Paul: 12. Teaching in the University the Day After Tomorrow. - Masschelein, Jan; Simons, Maarten: 13. The University: A Public Issue. - Van Wyk, Berte; Higgs, Philip: 14. The Future of University Research in Africa. - Peters, Michael; Gietzen, Garett; Ondercin, David J.: 15. Knowledge Socialism: Intellectual Commons and Openness in the University). Barnett, Ronald: CODA. (HDZD/text adopted)'.
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