This review investigated three research questions (i) What is the utility of social cognitive theory (SCT) to explain physical activity (PA)?; (ii) Is the effectiveness of SCT moderated by sample or ...methodological characteristics? and (iii) What is the frequency of significant associations between the core SCT constructs and PA? Ten electronic databases were searched with no date or sample restrictions. Forty‐four studies were retrieved containing 55 SCT models of PA. Methodological quality was assessed using a standardized tool. A random‐effects meta‐analysis revealed that SCT accounted for 31% of the variance in PA. However, methodological quality was mostly poor for these models. Methodological quality and sample age moderated the PA effect size, with increases in both associated with greater variance explained. Although self‐efficacy and goals were consistently associated with PA, outcome expectations and socio‐structural factors were not. This review determined that SCT is a useful framework to explain PA behaviour. Higher quality models explained more PA variance, but overall methodological quality was poor. As such, high‐quality studies examining the utility of SCT to explain PA are warranted.
Interneurons in the deep dorsal horn (DDH) of the spinal cord process somatosensory input, and form an important link between upper and lower motoneurons to subsequently shape motor output. Exercise ...training after SCI is known to improve functional motor recovery, but little is known about the mechanisms within spinal cord neurons that underlie these improvements. Here we investigate how the properties of DDH interneurons are affected by spinal cord injury (SCI) alone, and SCI in combination with different ‘doses’ of treadmill exercise training (3, 6, and 9wks). In an adult mouse hemisection model of SCI we used whole-cell patch-clamp electrophysiology to record intrinsic, AP firing and gain modulation properties from DDH interneurons in a horizontal spinal cord slice preparation. We find that neurons within two segments of the injury, both ipsi- and contralateral to the hemisection, are similarly affected by SCI and SCI plus exercise. The passive intrinsic membrane properties input resistance (Rin) and rheobase are sensitive to the effects of recovery time and exercise training after SCI thus altering DDH interneuron excitability. Conversely, select active membrane properties are largely unaffected by either SCI or exercise training. SCI itself causes a mismatch in the expression of voltage-gated subthreshold currents and AP discharge firing type. Over time after SCI, and especially with exercise training (9wks), this mismatched expression is exacerbated. Lastly, amplification properties (i.e. gain of frequency-current relationship) of DDH interneurons are altered by SCI alone and recover spontaneously with no clear effect of exercise training. These results suggest a larger ‘dose’ of exercise training (9wks) has a strong and selective effect on specific membrane properties, and on the output of interneurons in the vicinity of a SCI. These electrophysiological data provide new insights into the plasticity of DDH interneurons and the mechanisms by which exercise therapy after SCI can improve recovery.
•We characterized interneuron membrane properties after SCI and three exercise doses.•Patch-clamp electrophysiology of interneurons in mouse hemisection model of SCI.•Passive membrane properties more sensitive to recovery time and exercise after SCI.•AP discharge type and underlying subthreshold currents are mismatched after SCI.•Interneurons dynamically regulate excitability after SCI, independent of exercise.
Abstract The renin-angiotensin system (RAS) is thought to regulate placentation, however, the expression and localization of RAS pathways in early gestation human placenta is not known. Here we ...describe the expression of prorenin ( REN ), (pro)renin receptor ( ATP6AP2 ), angiotensinogen ( AGT ), angiotensin-converting enzyme 1 and 2 ( ACE; ACE2 ), angiotensin II type 1 and 2 receptors ( AGTR1; AGTR2 ) and angiotensin 1–7 receptor ( MAS1 ), as well as the angiogenic factor, vascular endothelial growth factor ( VEGF ), and transforming growth factor-β1 ( TGF-β1 ), in early gestation (6–16 weeks) and term (>37 weeks) human placentae. We also describe the location of all of the key RAS proteins in the early gestation placentae. The highest levels of REN, ATP6AP2, AGT, AGTR1 and ACE2 mRNAs were found in early gestation, whereas ACE1 mRNA was highest at term. AGTR2 and MAS1 mRNA expression were low to undetectable in all samples. REN , ATP6AP2 and AGTR1 mRNA levels were correlated with VEGF expression, but not with TGF-β1 mRNA. In early gestation placentae, prorenin, (pro)renin receptor and the angiotensin II type 1 receptor (AT1 R) were localized to extravillous trophoblast cells, suggesting they play a key role in trophoblast migration. ACE2 in syncytiotrophoblasts could regulate release of Ang 1-7 into the maternal circulation contributing to the vasodilation of the maternal vasculature. ACE was only found in fetal vascular endothelium and may specifically target the growing fetal placental vessels. Because REN , ATP6AP2 and AGTR1 show strong correlations with expression of VEGF this pathway is likely to be important in placental angiogenesis.
Summary
Background
Obesity and asthma are associated conditions; however, the mechanisms linking the two remain unclear. Few studies have examined the effects of weight loss on inflammation and ...clinical outcomes in obese–asthma.
Objective
To compare the effects of weight loss achieved by dietary restriction, exercise or combined dietary restriction and exercise on airway inflammation and clinical outcomes in overweight and obese adults with asthma.
Methods
Participants (n = 46; 54.3% female, body mass index (mean ± SD) 33.7 ± 3.5 kg/m2) were randomized to complete a 10‐week dietary, exercise or combined dietary and exercise intervention. Dual‐energy x‐ray absorptiometry was performed, the Juniper Asthma Control Questionnaire and Juniper Asthma Quality of Life Questionnaire completed and inflammatory markers, dietary intake and physical activity measured. The trial was registered with the Australian Clinical Trials Registry: ACTRN12611000235909.
Results
Retention was 82.6%. Mean ± SD weight loss was 8.5 ± 4.2%, 1.8 ± 2.6% and 8.3 ± 4.9% after the dietary, exercise and combined interventions respectively. Asthma control improved after the dietary (mean ± SD; −0.6 ± 0.5, P ≤ 0.001) and combined interventions (−0.5 ± 0.7, P = 0.040), whereas quality of life improved after the dietary median (IQR); 0.9 (0.4, 1.3), P = 0.002, exercise 0.49 (0.03, 0.78), P = 0.037 and combined 0.5 (0.1, 1.0), P = 0.007 interventions. A 5–10% weight loss resulted in clinically important improvements to asthma control in 58%, and quality of life in 83%, of subjects. Gynoid adipose tissue reduction was associated with reduced neutrophilic airway inflammation in women β‐coefficient (95% CI); 1.75 (0.02, 3.48), P = 0.047, whereas a reduction in dietary saturated fat was associated with reduced neutrophilic airway inflammation in males (r = 0.775, P = 0.041). The exercise intervention resulted in a significant reduction to sputum eosinophils median (IQR); −1.3 (−2.0, −1.0)%, P = 0.028.
Conclusion and clinical relevance
This study suggests a weight‐loss goal of 5–10% be recommended to assist in the clinical management of overweight and obese adults with asthma. The obese–asthma phenotype may involve both innate and allergic inflammatory pathways.
Key points
Exercise training after spinal cord injury (SCI) enhances collateral sprouting from axons near the injury and is thought to promote intraspinal circuit reorganisation that effectively ...bridges the SCI. The effects of exercise training, and its duration, on interneurons in these de novo intraspinal circuits are poorly understood.
In an adult mouse hemisection model of SCI, we used whole‐cell patch‐clamp electrophysiology to examine changes in the intrinsic and synaptic properties of deep dorsal horn interneurons in the vicinity of a SCI in response to the injury, and after 3 and 6 weeks of treadmill exercise training.
SCI alone exerted powerful effects on the intrinsic and synaptic properties of interneurons near the lesion.
Importantly, synaptic activity, both local and descending, was preferentially enhanced by exercise training, suggesting that exercise promotes synaptic plasticity in spinal cord interneurons that are ideally placed to form new intraspinal circuits after SCI.
Following incomplete spinal cord injury (SCI), collaterals sprout from intact and injured axons in the vicinity of the lesion. These sprouts are thought to form new synaptic contacts that effectively bypass the lesion epicentre and contribute to improved functional recovery. Such anatomical changes are known to be enhanced by exercise training; however, the mechanisms underlying exercise‐mediated plasticity are poorly understood. Specifically, we do not know how SCI alone or SCI combined with exercise alters the intrinsic and synaptic properties of interneurons in the vicinity of a SCI. Here we use a hemisection model of incomplete SCI in adult mice and whole‐cell patch‐clamp recording in a horizontal spinal cord slice preparation to examine the functional properties of deep dorsal horn (DDH) interneurons located in the vicinity of a SCI following 3 or 6 weeks of treadmill exercise training. We examined the functional properties of local and descending excitatory synaptic connections by recording spontaneous excitatory postsynaptic currents (sEPSCs) and responses to dorsal column stimulation, respectively. We find that SCI in untrained animals exerts powerful effects on intrinsic, and especially, synaptic properties of DDH interneurons. Plasticity in intrinsic properties was most prominent at 3 weeks post SCI, whereas synaptic plasticity was greatest at 6 weeks post injury. Exercise training did not markedly affect intrinsic membrane properties; however, local and descending excitatory synaptic drive were enhanced by 3 and 6 weeks of training. These results suggest exercise promotes synaptic plasticity in spinal cord interneurons that are ideally placed to form new intraspinal circuits after SCI.
Effective strategies are required to reduce the prevalence of overweight and obesity; however, the effectiveness of current weight loss programmes is variable. One contributing factor may be the ...difference in weight loss success between men and women. A systematic review was conducted to determine whether the effectiveness of weight loss interventions differs between men and women. Randomized controlled trials published up until March 2014 were included. Effect sizes (Hedges' g) were used to examine the difference in weight outcomes between men and women. A total of 58 studies met the eligibility criteria with 49 studies of higher quality included in the final data synthesis. Eleven studies that directly compared weight loss in men and women reported a significant sex difference. Ten of these reported that men lost more weight than women; however, women also lost a significant amount of weight. Analysis of effect sizes found small differences in weight loss favouring men for both diet (g = 0.489) and diet plus exercise (g = 0.240) interventions. There is little evidence from this review to indicate that men and women should adopt different weight loss strategies. Current evidence supports moderate energy restriction in combination with exercise for weight loss in both men and women.
A systematic review of randomized controlled trials was conducted to evaluate the effectiveness of eHealth interventions for the prevention and treatment of overweight and obesity in adults. Eight ...databases were searched for studies published in English from 1995 to 17 September 2014. Eighty‐four studies were included, with 183 intervention arms, of which 76% (n = 139) included an eHealth component. Sixty‐one studies had the primary aim of weight loss, 10 weight loss maintenance, eight weight gain prevention, and five weight loss and maintenance. eHealth interventions were predominantly delivered using the Internet, but also email, text messages, monitoring devices, mobile applications, computer programs, podcasts and personal digital assistants. Forty percent (n = 55) of interventions used more than one type of technology, and 43.2% (n = 60) were delivered solely using eHealth technologies. Meta‐analyses demonstrated significantly greater weight loss (kg) in eHealth weight loss interventions compared with control (MD −2.70 −3.33,−2.08, P < 0.001) or minimal interventions (MD −1.40 −1.98,−0.82, P < 0.001), and in eHealth weight loss interventions with extra components or technologies (MD 1.46 0.80, 2.13, P < 0.001) compared with standard eHealth programmes. The findings support the use of eHealth interventions as a treatment option for obesity, but there is insufficient evidence for the effectiveness of eHealth interventions for weight loss maintenance or weight gain prevention.
In the weeks and months following an incomplete spinal cord injury (SCI) significant spontaneous recovery of function occurs in the absence of any applied therapeutic intervention. The anatomical ...correlates of this spontaneous plasticity are well characterized, however, the functional changes that occur in spinal cord interneurons after injury are poorly understood. Here we use a T10 hemisection model of SCI in adult mice (9–10wks old) combined with whole-cell patch clamp electrophysiology and a horizontal spinal cord slice preparation to examine changes in intrinsic membrane and synaptic properties of deep dorsal horn (DDH) interneurons. We made these measurements during short-term (4wks) and long-term (10wks) spontaneous recovery after SCI. Several important intrinsic membrane properties are altered in the short-term, but recover to values resembling those of uninjured controls in the longer term. AP discharge patterns are reorganized at both short-term and long-term recovery time points. This is matched by reorganization in the expression of voltage-activated potassium and calcium subthreshold-currents that shape AP discharge. Excitatory synaptic inputs onto DDH interneurons are significantly restructured in long-term SCI mice. Plots of sEPSC peak amplitude vs. rise times suggest considerable dendritic expansion or synaptic reorganization occurs especially during long-term recovery from SCI. Connectivity between descending dorsal column pathways and DDH interneurons is reduced in the short-term, but amplified in long-term recovery. Our results suggest considerable plasticity in both intrinsic and synaptic mechanisms occurs spontaneously in DDH interneurons following SCI and takes a minimum of 10wks after the initial injury to stabilize.
•Plasticity in spinal neurons examined in short vs. long-term recovery after SCI.•Patch-clamp recordings made in interneurons in mouse hemisection model of SCI.•Passive intrinsic membrane properties recover to uninjured levels in long-term SCI.•Long-term SCI is characterized by dendritic expansion and synaptic reorganization.•Intrinsic and synaptic plasticity after SCI takes at least 10weeks to stabilize.
To examine the long-term effects of having one overweight or obese parent on child weight status and determine whether these effects vary according to parent sex.
Prospective study: Longitudinal ...Study of Australian Children (LSAC).
Two-parent families (N=3285) from the LSAC were included if height and weight data were available for both parents and their child at the 2004 and 2008 time points.
Child weight status category (healthy, overweight, obese) in 2008 when the child was aged 8-9 years. Regression modelling was used to investigate how self-reported parent weight status in 2004 influenced measured child weight status 4 years later.
Parent body mass index (BMI) was significantly correlated with child BMI, but there was no evidence of sex-specific associations between parent and child BMI correlations. The results from the regression analysis showed that having an overweight or obese father, but a healthy weight mother, significantly increased the odds of child obesity (odds ratio: 4.18, 95% confidence interval (CI): 1.01-17.33 and odds ratio: 14.88, 95% CI: 2.61-84.77, respectively), but the reverse scenario (overweight or obese mother with a healthy weight father) was not a significant predictor of child overweight or obesity (odds ratio: 2.52, 95% CI: 0.38-16.71 and odds ratio: 2.56, 95% CI: 0.31-21.26, respectively).
Children with overweight or obese fathers are at a higher risk of becoming obese. This suggests that interventions are urgently required to test the efficacy of treating overweight fathers as a key strategy for childhood obesity prevention and/or treatment.
The rapid increase in exposure to matches or contact at the start of a season may increase injury risk; conversely, accumulation of training and match stress may increase risk towards the end of a ...season. The team physiotherapist recorded injuries according to the Rugby Injury Consensus Group guidelines, classifying injuries by body location, severity, new vs recurrent, and contact vs non-contact. Increasing numbers of non-contact and recurrent injuries later in the season may suggest that in-season training loads, playing exposures or return the play strategies could be investigated to reduce injuries.
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