The importance of family support to engage and retain girls in male dominated action sports. A qualitative study of young people's perspectives

ISSUE ADDRESSED

Social support is positively correlated with physical activity (PA), especially amongst girls, but is underexplored in male-dominated action sports (e.g., mountain biking, skateboarding and surfing). This study explored family level social support needs and experiences of girls and boys in three action sports.

METHOD

Aspiring, current or former Australian adolescent (12-18 years; girls n = 25; boys n = 17) mountain bikers, skateboarders and/or surfers were individually interviewed (telephone/Skype) in 2018/2020. A socio-ecological framework guided the semi-structured interview schedule. Audio-recordings were transcribed verbatim and data analysed thematically using a constant comparative approach.

RESULTS

Family level social support was highly influential in young people's participation in action sports, with its absence a common reason for no or discontinued engagement amongst girls. Parents and siblings were the main social support providers with extended family (e.g., grandparents, aunts/uncles, cousins) also notable. Participation (current/past/co-) was the main social support type followed by emotional (e.g., encouragement), instrumental (e.g., transport, equipment/funding) and informational (e.g., coaching) support. Girls were inspired/encouraged by brothers but boys were not inspired/encouraged by sisters; boys and girls co-participated with both parents but co-participating and being inspired by fathers was most common, especially amongst girls; fathers were more commonly the main transport provider if they co-participated with their child; fathers mostly provided initial coaching; only boys were taught equipment maintenance by parents.

CONCLUSIONS AND SO WHAT

Sport-related organisations/groups have numerous opportunities to improve girls' representation in action sports by fostering family level social support through various means. Intervention strategies should be tailored to account for gendered participation differences.

trips4health: a single-blinded randomised controlled trial incentivising adult public transport use for physical activity gain

BACKGROUND

Public transport users tend to accumulate more physical activity than non-users; however, whether physical activity is increased by financially incentivising public transport use is unknown. The trips4health study aimed to determine the impact of an incentive-based public transport intervention on physical activity.

METHODS

A single-blinded randomised control trial of a 16-week incentive-based intervention involved Australian adults who were infrequent bus users (≥ 18 years; used bus ≤ 2 times/week) split equally into intervention and control groups. The intervention group were sent weekly motivational text messages and awarded smartcard bus credit when targets were met. The intervention group and control group received physical activity guidelines. Accelerometer-measured steps/day (primary outcome), self-reported transport-related physical activity (walking and cycling for transport) and total physical activity (min/week and MET-min/week) outcomes were assessed at baseline and follow-up.

RESULTS

Due to the COVID pandemic, the trial was abandoned prior to target sample size achievement and completion of all assessments (N = 110). Steps/day declined in both groups, but by less in the intervention group [-557.9 steps (-7.9%) vs.-1018.3 steps/week (-13.8%)]. In the intervention group, transport-related physical activity increased [80.0 min/week (133.3%); 264.0 MET-min/week (133.3%)] while total physical activity levels saw little change [35.0 min/week (5.5%); 25.5 MET-min/week (1.0%)]. Control group transport-related physical activity decreased [-20.0 min/week (-27.6%); -41.3 MET-min/week (-17.3%)], but total physical activity increased [260.0 min/week (54.5%); 734.3 MET-min/week (37.4%)].

CONCLUSION

This study found evidence that financial incentive-based intervention to increase public transport use is effective in increasing transport-related physical activity These results warrant future examination of physical activity incentives programs in a fully powered study with longer-term follow-up.

TRIAL REGISTRATION

This trial was registered with the Australian and New Zealand Clinical Trials Registry August 14th, 2019: ACTRN12619001136190; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377914&isReview=true.

Antibiotic therapy in dogs and cats in general practise in the United Kingdom before referral

OBJECTIVES

To describe antibiotic prescription by veterinarians in general practises in the United Kingdom before referral and analyse if UK antibiotic stewardship guidelines were followed.

MATERIALS AND METHODS

The clinical records from dogs and cats referred to the Internal Medicine and Oncology departments of two referral hospitals were retrospectively reviewed.

RESULTS

There were 917 cases included, of which 486 (53.0%) had been prescribed antibiotics for the presentation they were subsequently referred for. Bacterial culture or cytology to guide antibiotic prescription had been performed in 43 of 486 (8.8%) and nine of 486 cases (1.8%) respectively. In four cases, both cytology and culture were performed. For those animals who had received antibiotics, 344 of 486 (70.8%) prescriptions did not comply with UK antibiotic stewardship guidelines. Following investigations at a referral centre, a bacterial aetiology was found or suspected in 17.9% of the cases that received antibiotics.

CLINICAL SIGNIFICANCE

Use of diagnostics, including culture and cytology, to prove or determine the likelihood of a bacterial aetiology was infrequently performed before referral and may have contributed to overprescription of antibiotics. Encouraging veterinarians to undertake appropriate diagnostics, in combination with education around compliance with antibiotic stewardship guidelines, might reduce antibiotic prescription.

Is greater public transport use associated with higher levels of physical activity in a regional setting? Findings from a pilot study

BACKGROUND

Public transport users often accumulate more physical activity than motor vehicle users, but most studies have been conducted in large metropolitan areas with multiple public transport options with limited knowledge of the relationship in regional and rural areas. In a regional city, this pilot study aimed to (1) test the feasibility of preliminary hypotheses to inform future research, (2) test the utility of survey items, and (3) establish stakeholder engagement.

METHODS

Data were collected via a cross-sectional online survey of 743 Tasmanian adults. Physical activity outcomes were walking (min/week), total moderate- to vigorous-intensity physical activity (min/week) and attainment of physical activity guidelines (yes/no). Transport variables were frequency of public and private transport use per week. Truncated and log binomial regression examined associations between public/private transport use and physical activity.

RESULTS

Neither frequency of public nor private transport use was associated with minutes of walking (public transport: B - 24.4, 95% CI: - 110.7, 61.9; private transport: B - 1.1, 95% CI: - 72.4, 70.1), minutes of total physical activity (public transport: B - 90.8, 95% CI: - 310.0, 128.5; private transport: B 0.4, 95% CI: - 134.0, 134.9) or not meeting physical activity guidelines (public transport: RR 1.02, 95%CI: 0.95, 1.09; private transport: RR 1.02, 95%CI: 0.96, 1.08).

CONCLUSIONS

The hypothesis that public transport users would be more physically active than private transport users was not supported in this pilot study. Stakeholders were engaged and involved in various phases of the research including development of research questions, participant recruitment, and interpretation of findings. Further studies using representative samples and refined measures are warranted to confirm or refute findings.

Childhood factors related to diverging body mass index trajectories from childhood into mid-adulthood: A mixed methods study

Body mass index (BMI) trajectories that improve over the lifecourse result in better cardiometabolic profiles, but only a small proportion of children of an unhealthy weight show improving BMI trajectories. This study aimed to examine the childhood factors related to diverging BMI trajectories from childhood into adulthood using data from the Childhood Determinants of Adult Health study. A convergent parallel mixed methods design was used. Quantitative data (n = 2206) came from the first (2004-06) and second (2009-11) adult follow-ups of 8498 Australian children (7-15 years) assessed in 1985. Using BMI z-scores, group-based trajectory modelling identified five trajectory groups: Persistently Low, Persistently Average, High Decreasing, Average Increasing and High Increasing. Qualitative data (n = 50) were collected from a sub-group (2016; 38-46 years). Semi-structured interviews with 6-12 participants from each BMI trajectory group focused on individual, social and environmental influences on weight, diet and physical activity across the lifecourse. Log multinomial regression modelling estimated relative risks of trajectory group membership across childhood demographic, behavioural, health, parental and school factors. Qualitative data were thematically analysed using a constant comparative approach. Childhood factors influenced BMI trajectories. Paternal education, main language spoken, alcohol and self-rated health were significant quantitative childhood predictors of BMI trajectory. A distinct 'legacy effect' of parental lifestyle influences during childhood was apparent among interview participants in the Stable and High Decreasing groups, a strong and mostly positive concept discussed by both men and women in these groups and persisting despite phases of unhealthy behaviours. In contrast, the 'legacy effect' was much weaker in the two Increasing BMI groups. This study is the first to simultaneously identify important quantitative and qualitative childhood factors related to divergent BMI trajectories, and to observe a legacy effect of parents' lifestyle behaviours on divergent BMI trajectories. This work provides direction for further exploration of the factors driving divergent BMI trajectories.

trips4health: Protocol of a single-blinded randomised controlled trial incentivising adults to use public transport for physical activity gain

Background

Public transport (PT) users typically accumulate more physical activity (PA) than private motor vehicle users yet redressing physical inactivity through transport-related PA (TRPA) interventions has received limited attention. Further, incentive-based strategies can increase leisure-time PA but their impact on TRPA, is unclear. This study's objective is to determine the impact of an incentive-based strategy on TRPA in a regional Australian setting.

Methods

trips4health is a single-blinded randomised controlled trial with a four-month intervention phase and subsequent six-month maintenance phase. Participants will be randomised to: an incentives-based intervention (bus trip credit for reaching bus trip targets, weekly text messages to support greater bus use, written PA guidelines); or an active control (written PA guidelines only). Three hundred and fifty adults (≥18 years) from southern Tasmania will be recruited through convenience methods, provide informed consent and baseline information, then be randomised. The primary outcome is change in accelerometer measured average daily step count at baseline and four- and ten-months later. Secondary outcomes are changes in: measured and self-reported travel behaviour (e.g. PT use), PA, sedentary behaviour; self-reported and measured (blood pressure, waist circumference, height, weight) health; travel behaviour perspectives (e.g. enablers/barriers); quality of life; and transport-related costs. Linear mixed model regression will determine group differences. Participant and PT provider level process evaluations will be conducted and intervention costs to the provider determined.

Discussion

trips4health will determine the effectiveness of an incentive-based strategy to increase TRPA by targeting PT use. The findings will enable evidence-informed decisions about the worthwhileness of such strategies.

Trial registration

ACTRN12619001136190.

Universal trial number

U1111-1233-8050.

Test-retest reliability of a self-reported physical activity environment instrument for use in rural settings

OBJECTIVE

Little is known about how the physical environment impacts physical activity behaviour among rural populations, who are typically less active and at higher risk of chronic disease than urban dwellers. The lack of individual-level instruments to assess the physical environment in rural areas limits advancement of this field. Among rural adults, this study aimed to evaluate (a) the test-retest reliability of a self-reported questionnaire of individual-level perceptions of the physical activity environment, and (b) the stability of a self-reported physical activity questionnaire.

DESIGN

Cross-sectional questionnaire repeated twice, 2 weeks apart. The questionnaire included 94 items relating to the perceived physical environment (representing nine summary scores), demographic characteristics and physical activity.

SETTING

Rural Australia.

PARTICIPANTS

Rurally residing adults (≥18 years) across three Australian states.

MAIN OUTCOME MEASURES

Test-retest reliability evaluated by weighted Kappa statistics (individual items) and intra-class correlations (summary scores).

RESULTS

A total of 292 participants (20% men) completed both questionnaires, on average 22 days apart. Test-retest reliability of individual items ranged from weighted Kappa 0.37-0.85 (median: 0.59). Internal reliability for five summary scores was good to excellent (Cronbach's alpha: 0.81-0.97). Test-retest reliability was good to excellent for six summary scores (intra-class correlations: 0.67-0.77).

CONCLUSIONS

The findings indicated good to excellent test-retest reliability for most items, particularly "fixed" constructs for this new questionnaire measuring the perceived physical environment in rural populations. This study represents an important step towards improving measurement of physical activity environments in rural populations, potentially leading to better tailored interventions to promote active and healthy living in rural areas.

Acceptability and perceived feasibility of strategies to increase public transport use for physical activity gain - A mixed methods study

ISSUE ADDRESSED

Public transport (PT) users typically accumulate more physical activity (PA) than motor vehicle users. This mixed methods study aimed to determine acceptability and perceived effectiveness of strategies to increase bus use for PA gain in a regional Australian setting.

METHODS

In a 2017 online survey, Tasmanian adults (n = 1091) rated the likelihood of increasing their bus use according to ten hypothetical strategies (fare-, incentives-, information- or infrastructure-based). Three focus groups and five interviews (n = 31) included infrequent bus users from the survey to determine reasons for strategy preferences and potential impact on PA.

RESULTS

The top three strategies in the survey, with supporting rationale from qualitative data, were: provision of real-time bus information ("…because I can better plan…"); bus-only lanes ("…it just speeds the whole thing up…") and employee incentives/rewards for example bus fare credits ("…it really comes down to money…"). Full-time students favoured cost-saving strategies most and residents in outer suburbs favoured infrastructure-based strategies most. Qualitative data indicated that potential for enhanced certainty, efficiency or cost-savings drove strategy preferences and some strategies may lead to PA gain (eg through the location of Park and Ride facilities).

CONCLUSIONS

Real-time information, bus-only lanes and employee incentives/rewards appear most promising for increasing bus use in this population, but tailoring strategies may be required. Discrete PT enhancement strategies may result in PA gain. SO WHAT?: Increasing PA through transport behaviour has been underexplored. The potential for PA gain through greater PT use and discrete PT use enhancement strategies is an important public health consideration.

"I love having a healthy lifestyle" - a qualitative study investigating body mass index trajectories from childhood to mid-adulthood

Background

Children with overweight or obesity are at greatly increased risk of experiencing obesity in adulthood but for reasons generally unknown some attain a healthier adult weight. This qualitative study investigated individual, social and environmental factors that might explain diverging body mass index (BMI) trajectories. This knowledge could underpin interventions to promote healthy weight.

Methods

This 2016 study included participants from three adult follow-ups of children who (when 7–15 years) participated in the 1985 Australian Schools Health and Fitness Survey and provided BMI data at each time point. Trajectory-based group modelling identified five BMI trajectories: stable below average, stable average, increasing from average, increasing from very high and decreasing from very high. Between six and 12 participants (38–46 years) from each BMI trajectory group were interviewed (n = 50; 60% women). Thematic analysis guided by a social-ecological framework explored individual, social and environmental influences on diet and physical activity within the work setting.

Results

A distinct approach to healthy behaviour was principally identified in the stable and decreasing BMI groups – we term this approach “health identity” (exemplified by “I love having a healthy lifestyle”). This concept was predominant in the stable or decreasing BMI groups when participants explained why work colleagues seemingly did not influence their health behaviour. Participants in the stable and decreasing BMI groups also more commonly reported, bringing home-prepared lunches to work, working or being educated in a health-related field, having a physically active job or situating physical activity within and around work – the latter three factors were common among those who appeared to have a more distinct “health identity”. Alcohol, workplace food culture (e.g. morning teas), and work-related stress appeared to influence weight-related behaviours, but generally these factors were similarly discussed across all trajectory groups.

Conclusion

Work-related factors may influence weight or weight-related behaviours, irrespective of BMI trajectory, but the concept of an individual’s “health identity” may help to explain divergent BMI trajectories. “Health identity” and its influence on health behaviour warrants further exploratory work.

Electronic supplementary material

The online version of this article (10.1186/s40608-019-0239-3) contains supplementary material, which is available to authorized users.

Health and broader community benefit of parkrun-An exploratory qualitative study

ISSUE ADDRESSED

parkrun is a free, weekly, timed, international mass community 5-km walk/run event. Unlike other paid events, parkrun attracts populations harder to engage in physical activity (PA) (eg, women, those with overweight/obesity or illness/injury/disability). This exploratory qualitative study investigated the individual, social and environmental factors associated with parkrun's broad appeal in Australia.

METHODS

Tasmanian parkrunners who completed a quantitative survey (2016) were purposively recruited for a 2017 interview study. Semistructured interviews focused on reasons for parkrun participation. Data saturation was achieved by the tenth interview. Data were analysed thematically.

RESULTS

Four themes emerged: (a) participation facilitators and barriers; (b) PA gain and broader community benefit; (c) social connections/networks; and (d) organisational issues. Appealing characteristics of parkrun included strong social support, performance gain opportunities, socialising, inclusivity (eg, all ages/abilities), sense of community, positive atmosphere and accessibility (eg, no cost and convenience). Some participants reported that parkrun had stimulated gains in their total PA (not always limited to walking/running) and that parkrun may also result in other community benefits (eg, supporting local businesses, fee-based running club/event participation and "parkrun tourism"). Most participants first attended parkrun because of encouragement from their social networks, and participants subsequently encouraged others to attend. Participants found parkrun events well organised, but identified some potential threats (eg, local politics).

CONCLUSIONS

Social factors appeared critical in driving initial and ongoing parkrun participation. parkrun may lead to wider community benefits beyond that gained through increased individual PA. These findings highlight the "success factors" driving parkrun participation and provide insights for other community-based PA promotion activities.

A qualitative investigation of the health economic impacts of bariatric surgery for obesity and implications for improved practice in health economics

Obesity is an economic problem. Bariatric surgery is cost-effective for severe and resistant obesity. Most economic evaluations of bariatric surgery use administrative data and narrowly defined direct medical costs in their quantitative analyses. Demand far outstrips supply for bariatric surgery. Further allocation of health care resources to bariatric surgery (particularly public) could be stimulated by new health economic evidence that supports the provision of bariatric surgery. We postulated that qualitative research methods would elicit important health economic dimensions of bariatric surgery that would typically be omitted from the current economic evaluation framework, nor be reported and therefore not considered by policymakers with sufficient priority. We listened to patients: Focus group data were analysed thematically with software assistance. Key themes were identified inductively through a dialogue between the qualitative data and pre-existing economic theory (perspective, externalities, and emotional capital). We identified the concept of emotional capital where participants described life-changing desires to be productive and participate in their communities postoperatively. After self-funding bariatric surgery, some participants experienced financial distress. We recommend a mixed-methods approach to the economic evaluation of bariatric surgery. This could be operationalised in health economic model conceptualisation and construction, through to the separate reporting of qualitative results to supplement quantitative results.

Exploring the Health-Promoting Potential of the “parkrun” Phenomenon: What Factors are Associated With Higher Levels of Participation?

Purpose:

“ parkrun” is a free and increasingly popular weekly 5-km walk/run international community event, representing a novel setting for physical activity (PA) promotion. However, little is known about who participates or why. This study aimed to identify sociodemographic, health, behavioral, individual, social, and environmental factors associated with higher levels of participation.

Design:

Cross-sectional.

Setting:

Tasmania, Australia; June 2016.

Participants:

Three hundred seventy two adult parkrun participants.

Measures:

Online survey measuring sociodemographic, health, individual, social and environmental factors, parkrun participation, and PA.

Analysis:

Descriptive statistics, zero-truncated Poisson regression models.

Results:

Respondents (n = 371) were more commonly women (58%), aged 35 to 53 years (54%), and occasional or nonwalkers/runners (53%) at registration. A total of 44% had overweight/obesity. Half had non-adult children, most spoke English at home, and 7% reported PA-limiting illness/injury/disability. Average run/walk time was 30.2 ± 7.4 minutes. Compared to regular walkers/runners at registration, nonwalkers/runners were less commonly partnered, more commonly had overweight/obesity, less physically active, and had poorer self-rated health. Multivariate analyses revealed relative parkrun participation was inversely associated with education level and positively associated with interstate parkrun participation, perceived social benefits, self-efficacy for parkrun, and intentions to participate.

Conclusion:

parkrun attracts nonwalkers/runners and population groups hard to engage in physical activity. Individual- and social-level factors were associated with higher relative parkrun participation. parkrun’s scalability, accessibility, and wide appeal confers a research imperative to investigate its potential for public health gain.

Population estimates and characteristics of Australians potentially eligible for bariatric surgery: findings from the 2011–13 Australian Health Survey

Objective The aim of the present study was to determine the potential demand for publicly and privately funded bariatric surgery in Australia. Methods Nationally representative data from the 2011–13 Australian Health Survey were used to estimate the numbers and characteristics of Australians meeting specific eligibility criteria as recommended in National Health and Medical Research Council guidelines for the management of overweight and obesity. Results Of the 3 352 037 adult Australians (aged 18–65 years) estimated to be obese in 2011–13, 882 441 (26.3%; 95% confidence interval (CI) 23.0–29.6) were potentially eligible for bariatric surgery (accounting for 6.2% (95% CI 5.4–7.1) of the adult population aged 18–65 years (n = 14 122 020)). Of these, 396 856 (45.0%; 95% CI 40.4–49.5) had Class 3 obesity (body mass index (BMI) ≥40 kg m–2), 470945 (53.4%; 95% CI 49.0–57.7) had Class 2 obesity (BMI 35–39.9 kg m–2) with obesity-related comorbidities or risk factors and 14 640 (1.7%; 95% CI 0.6–2.7) had Class 1 obesity (BMI 30–34.9 kg m–2) with poorly controlled type 2 diabetes and increased cardiovascular risk; 458 869 (52.0%; 95% CI 46.4–57.6) were female, 404 594 (45.8%; 95% CI 37.3–54.4) had no private health insurance and 309 983 (35.1%; 95% CI 28.8–41.4) resided outside a major city. Conclusion Even if only 5% of Australian adults estimated to be eligible for bariatric surgery sought this intervention, the demand, particularly in the public health system and outside major cities, would far outstrip current capacity. Better guidance on patient prioritisation and greater resourcing of public surgery are needed. What is known about this topic? In the period 2011–13, 4 million Australian adults were estimated to be obese, with obesity disproportionately more prevalent in areas of socioeconomic disadvantage. Bariatric surgery is considered to be cost-effective and the most effective treatment for adults with obesity, but is mainly privately funded in Australia (>90%), with 16 650 primary privately funded procedures performed in 2015. The extent to which the supply of bariatric surgery is falling short of demand in Australia is unknown. What does this paper add? The present study provides important information for health service planners. For the first time, population estimates and characteristics of those potentially eligible for bariatric surgery in Australia have been described based on the best available evidence, using categories that best approximate the national recommended eligibility criteria. What are the implications for practitioners? Even if only 5% of those estimated to be potentially eligible for bariatric surgery in Australia sought a surgical pathway (44 122 of 882 441), the potential demand, particularly in the public health system and outside major cities, would still far outstrip current capacity, underscoring the immediate need for better guidance on patient prioritisation. The findings of the present study provide a strong signal that more funding of public surgery and other effective interventions to assist this population group are necessary.

The support needs of patients waiting for publicly funded bariatric surgery - implications for health service planners

The objective of this study was to investigate the experience of waiting for publicly funded bariatric surgery in an Australian tertiary healthcare setting. Focus groups and individual interviews involving people waiting for or who had undergone publicly funded bariatric surgery were audio-recorded, transcribed and analysed thematically. A total of 11 women and 6 men engaged in one of six focus groups in 2014, and an additional 10 women and 9 men were interviewed in 2015. Mean age was 53 years (range 23-66); mean waiting time was 6 years (range 0-12), and mean time since surgery was 4 years (range 0-11). Waiting was commonly reported as emotionally challenging (e.g. frustrating, depressing, stressful) and often associated with weight gain (despite weight-loss attempts) and deteriorating physical health (e.g. development of new or worsening obesity-related comorbidity or decline in mobility) or psychological health (e.g. development of or worsening depression). Peer support, health and mental health counselling, integrated care and better communication about waitlist position and management (e.g. patient prioritization) were identified support needs. Even if wait times cannot be reduced, better peer and health professional supports, together with better communication from health departments, may improve the experience or outcomes of waiting and confer quality-of-life gains irrespective of weight loss.

Two weeks of reduced-volume sprint interval or traditional exercise training does not improve metabolic functioning in sedentary obese men

AIMS

To investigate the effects of short-term, reduced-volume sprint interval training (SIT) compared to traditional exercise recommendations (TER) in sedentary obese men.

METHODS

Sixteen subjects [37.8 ± 5.8 years; body mass index (BMI) 32.8 ± 4.7 kg/m(2)] were randomly allocated to 2 weeks of either SIT (6 sessions of 8-12 × 10 s sprints) or TER [10 sessions of 30 min at 65% peak oxygen consumption (VO(2peak))] cycle exercise. Fasting plasma glucose, insulin, non-esterified fatty acids (NEFA), homeostasis model assessment of insulin sensitivity (HOMA-IR), body composition and VO(2peak) were assessed at baseline and approximately 72 h after the final training bout. Skeletal muscle biopsy samples were also obtained before and 72 h after training and analysed for AS160 phosphorylation and COX II, COX IV, GLUT-4, Nur77 and SIRT1 protein expression.

RESULTS

No changes in BMI, body composition, VO(2peak), glucose, insulin, NEFA and HOMA-IR were observed after training, either within or between groups. Skeletal muscle markers of glucose metabolism and mitochondrial function also remained unaltered after 2 weeks of exercise training.

CONCLUSIONS

Our findings show that 2 weeks of reduced-volume SIT or TER did not elicit any measurable metabolic adaptations in sedentary obese men. Further work is needed to determine the minimal amount of exercise required for short-term adaptations in this population.

In vivo confocal endomicroscopy of small intestinal mucosal morphology in dogs

BACKGROUND

Confocal endomicroscopy (CEM) is an endoscopic technology that permits in vivo cellular and subcellular imaging of the gastrointestinal mucosa.

OBJECTIVE

To determine the feasibility of CEM to evaluate small intestinal mucosal topologic morphology in dogs and to characterize the appearance in healthy dogs.

ANIMALS

Fourteen clinically healthy research colony dogs.

METHODS

Experimental study. Dogs were anesthetized for standard endoscopic evaluation of the small intestine followed by CEM. Two fluorophores were used to provide contrast: fluorescein (10% solution, 15 mg/kg IV) before administration of topical acriflavine (0.05% solution) via an endoscopy spray catheter. A minimum of 5 sites within the small intestine were assessed and at each location, sequential adjustment of imaging depth allowed collection of a three-dimensional volume equivalent to an 'optical biopsy'. CEM-guided pinch biopsies were obtained for histologic examination.

RESULTS

CEM provided high-quality in vivo cellular and subcellular images. Intravenous administration of fluorescein provided sufficient contrast to allow assessment of the vasculature, cellular cytoplasmic features and goblet cell numbers, and distribution. Topical application of acriflavine preferentially stained cellular nucleic acids, allowing evaluation of nuclear morphology. Quality of captured images was occasionally affected by motion artifact, but improved with operator experience.

CONCLUSION AND CLINICAL IMPORTANCE

CEM provides in vivo images that allow for cellular and subcellular assessment of intestinal mucosal morphology during endoscopy. This has implications for aiding in vivo diagnosis of gastrointestinal disease.

The exogenous fluorophore, fluorescein, enables in vivo assessment of the gastrointestinal mucosa via confocal endomicroscopy: optimization of intravenous dosing in the dog model

This study described the pharmacokinetics of the intravenous fluorophore, fluorescein, and aimed to evaluate its utility for use in upper gastrointestinal confocal endomicroscopy (CEM). Six healthy, mature, mixed-breed dogs were anesthetized and then dosed intravenously with fluorescein at 15 mg/kg. Blood samples were collected at predetermined time-points. Dogs were examined by upper gastrointestinal confocal endomicroscopy and monitored for adverse effects. Plasma fluorescein concentrations were measured using high-performance liquid chromatography (HPLC) with UV/Vis detection. Mean plasma concentration at 5 min was 57.6 ± 18.2 mg/L, and plasma concentrations decreased bi-exponentially thereafter with a mean concentration of 2.5 mg/L ± 1.26 at 120 min. Mean terminal plasma elimination half-life (t½β ) was 34.8 ± 8.94 min, and clearance was 9.1 ± 3.0 mL/kg/min. Apparent volume of distribution at steady-state was 0.3 ± 0.06 L/kg. Fluorescein provided optimal fluorescent contrast to enable in vivo histologically equivalent evaluation of topologic mucosal morphology within the first 30 min following intravenous administration. Adverse effects were not observed. Based upon the calculated clearance, a constant rate infusion at a rate of 0.18 mg/kg/min is predicted to be adequate, following an initial loading dose (2 mg/kg), to maintain plasma concentration at 20 mg/L for optimal CEM imaging during the study period.

Sinonasal aspergillosis in dogs: a review

Sinonasal aspergillosis is an uncommon, yet debilitating and often frustrating condition to treat in dogs despite years of research evaluating pathogenesis, diagnosis and treatment. The disease is most commonly caused by non-invasive fungal infection, thought to be secondary to altered innate and/or adaptive immune responses. Attempts to confirm this have however failed. A variety of conflicting opinions regarding the diagnosis and treatment of sinonasal aspergillosis exist. Often the use of a particular treatment protocol is based upon personal or regional preference. Evaluation of the veterinary literature demonstrates that the evidence base in support of individual treatment recommendations is weak. A number of recent publications have helped to expand the current knowledge base and therefore our understanding of important practicalities for both diagnostic options and treatment protocols. The following review examines the current evidence for the pathogenesis of sinonasal aspergillosis in dogs, as well as the various diagnostic options. The available evidence for frequently utilised -therapeutic options and their likely outcomes is also explored.

The effect of APOE genotype on brain levels of oxysterols in young and old human APOE epsilon2, epsilon3 and epsilon4 knock-in mice

Despite apolipoprotein E's important role in cholesterol transport and metabolism in the brain as well as its influence on Alzheimer's disease, the impact of the human APOE genotype on cholesterol metabolism in brain has not been fully examined. This study was carried out to investigate APOE genotype effects on oxysterols measured. In this study the measurement of cholesterol and several oxysterols in the brains of human APOE epsilon2, epsilon3 and epsilon4 knock-in mice at 8 weeks and 1 year of age using gas chromatography mass spectrometry (GC-MS) demonstrated no APOE genotype or age effect on total brain cholesterol and the oxysterol 24-hydroxycholesterol. The level of 27-hydroxycholesterol was elevated in 1 year old animals for all APOE genotypes. Interestingly, lathosterol an indicator of cholesterol synthesis was significantly reduced in the 1 year old animals for all APOE genotypes. APOE epsilon4 expressing mice exhibited statistically lower levels of lathosterol compared to APOE epsilon2 in both the young and old mice. Oxidized cholesterol metabolites were significantly lower in APOE epsilon2 mice compared to other genotypes at 8 weeks old. Although minimal differences were observed between APOE E3 and E4 knock-in (KI) mice, these findings indicate that there are some clear APOE genotype specific effects on brain cholesterol synthesis and associated metabolic pathways, particularly in APOE epsilon2 KI mice.

Proprioceptive Neuromuscular Facilitation Stretching

Proprioceptive neuromuscular facilitation (PNF) stretching techniques are commonly used in the athletic and clinical environments to enhance both active and passive range of motion (ROM) with a view to optimising motor performance and rehabilitation. PNF stretching is positioned in the literature as the most effective stretching technique when the aim is to increase ROM, particularly in respect to short-term changes in ROM. With due consideration of the heterogeneity across the applied PNF stretching research, a summary of the findings suggests that an 'active' PNF stretching technique achieves the greatest gains in ROM, e.g. utilising a shortening contraction of the opposing muscle to place the target muscle on stretch, followed by a static contraction of the target muscle. The inclusion of a shortening contraction of the opposing muscle appears to have the greatest impact on enhancing ROM. When including a static contraction of the target muscle, this needs to be held for approximately 3 seconds at no more than 20% of a maximum voluntary contraction. The greatest changes in ROM generally occur after the first repetition and in order to achieve more lasting changes in ROM, PNF stretching needs to be performed once or twice per week. The superior changes in ROM that PNF stretching often produces compared with other stretching techniques has traditionally been attributed to autogenic and/or reciprocal inhibition, although the literature does not support this hypothesis. Instead, and in the absence of a biomechanical explanation, the contemporary view proposes that PNF stretching influences the point at which stretch is perceived or tolerated. The mechanism(s) underpinning the change in stretch perception or tolerance are not known, although pain modulation has been suggested.

Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women

OBJECTIVE: To compare the effects of isocaloric, energy-restricted very low-carbohydrate ketogenic (VLCK) and low-fat (LF) diets on weight loss, body composition, trunk fat mass, and resting energy expenditure (REE) in overweight/obese men and women. DESIGN: Randomized, balanced, two diet period clinical intervention study. Subjects were prescribed two energy-restricted (-500 kcal/day) diets: a VLCK diet with a goal to decrease carbohydrate levels below 10% of energy and induce ketosis and a LF diet with a goal similar to national recommendations (%carbohydrate:fat:protein = ~60:25:15%). SUBJECTS: 15 healthy, overweight/obese men (mean +/- s.e.m.: age 33.2 +/- 2.9 y, body mass 109.1 +/- 4.6 kg, body mass index 34.1 +/- 1.1 kg/m2) and 13 premenopausal women (age 34.0 +/- 2.4 y, body mass 76.3 +/- 3.6 kg, body mass index 29.6 +/- 1.1 kg/m2). MEASUREMENTS: Weight loss, body composition, trunk fat (by dual-energy X-ray absorptiometry), and resting energy expenditure (REE) were determined at baseline and after each diet intervention. Data were analyzed for between group differences considering the first diet phase only and within group differences considering the response to both diets within each person. RESULTS: Actual nutrient intakes from food records during the VLCK (%carbohydrate:fat:protein = ~9:63:28%) and the LF (~58:22:20%) were significantly different. Dietary energy was restricted, but was slightly higher during the VLCK (1855 kcal/day) compared to the LF (1562 kcal/day) diet for men. Both between and within group comparisons revealed a distinct advantage of a VLCK over a LF diet for weight loss, total fat loss, and trunk fat loss for men (despite significantly greater energy intake). The majority of women also responded more favorably to the VLCK diet, especially in terms of trunk fat loss. The greater reduction in trunk fat was not merely due to the greater total fat loss, because the ratio of trunk fat/total fat was also significantly reduced during the VLCK diet in men and women. Absolute REE (kcal/day) was decreased with both diets as expected, but REE expressed relative to body mass (kcal/kg), was better maintained on the VLCK diet for men only. Individual responses clearly show the majority of men and women experience greater weight and fat loss on a VLCK than a LF diet. CONCLUSION: This study shows a clear benefit of a VLCK over LF diet for short-term body weight and fat loss, especially in men. A preferential loss of fat in the trunk region with a VLCK diet is novel and potentially clinically significant but requires further validation. These data provide additional support for the concept of metabolic advantage with diets representing extremes in macronutrient distribution.

Influence of muscle strength and total work on exercise-induced plasma growth hormone isoforms in women

The purpose of this investigation was to determine the influence of physical strength and the ability to do more total work on human growth hormone (GH) variants to a heavy resistance exercise protocol in untrained women. From a distribution of 100 healthy, untrained women, the strongest 10 women (S) and the weakest 10 women (W) were compared for GH responses pre- and post an acute heavy resistance exercise test (AHRET, 6 sets of 10 RM squats, 2 minutes rest between sets). Blood samples were obtained pre-exercise and immediately post-exercise and subsequently analysed in total as well as fractionated by Sephacryl S-100R column chromatography into three molecular weight size classes: fraction A: > 60 kD, fraction B: 30-60 kD, fraction C: < 30 kD. For each total sample as well as each fraction, immunoreactive GH was measured via the Nichols IRMA, while bioactive GH was measured via the hypox rat tibial line bioassay and Diagnostic Systems Laboratory's immunofunctional GH ELISA. No exercise-induced changes or differences between groups were observed in the tibial line bioassay. However, the S group displayed a significantly higher pre-exercise resting value in the total fraction than the W group. Conversely, the W group exhibited a significantly higher pre-exercise value in the smaller molecular weight fraction C. With regards to the immunofunctional and immunoreactive assays, the total fraction, fraction A, and fraction B demonstrated significant (P < or = 0.05) exercise-induced increases in both the S and W group despite no group differences. For the Nichols and immunofunctional assays significant exercise-induced changes were observed in the smaller molecular weight C fraction in the W group but not the S group. However, the S group displayed a significantly higher pre-exercise value in fraction C relative to the W group. These data demonstrate for the first time that differences exist in the GH molecular weight variants between strong and weak untrained women, with the lower molecular weight variants seemingly less responsive to greater amounts of exercise in stronger women, thus suggesting differential regulation of GH molecular weight variants during resistance exercise due to pre-existing physical parameters.

Muscle fiber characteristics in patients with peripheral arterial disease

PURPOSE

There have been conflicting reports of muscle fiber type changes in patients with peripheral arterial disease (PAD). The purpose of this study was to examine the myosin heavy chain (MHC) expression as well as histochemical changes in the gastrocnemius muscle in patients with symptomatic PAD.

METHODS

Needle biopsy specimens were obtained from the medial gastrocnemius of 14 subjects with PAD (mean age (+/- SD), 69.7 +/- 4.8 yr) and eight activity-matched control subjects (mean age, 65.1 +/- 6.6 yr). Ankle-brachial index was assessed using Doppler ultrasound to determine the hemodynamic status of the patients, and maximal walking performance was determined during a graded treadmill test. Expression of MHC isoforms was determined by SDS-PAGE.

RESULTS

The proportion of MHC I was significantly smaller in PAD than in the controls (45.6 +/- 9.1% vs 58.8 +/- 15.0%). The proportion of MHC IIx was also larger in the subjects with PAD compared with the controls (22.9 +/- 9.1% vs 16.0 +/- 11.3%). In addition, there was a significant decrease in the cross-sectional area of the type I and type IIA fibers in the subjects with PAD as well as enhanced capillary density.

CONCLUSIONS

This study showed a significant modification in the expression of MHC isoforms and muscle fiber type in the gastrocnemius in patients with symptomatic PAD. These results suggest that muscle ischemia resulting from PAD is an important factor in causing the adaptations in the contractile apparatus of the muscle.

Safety measures of L-carnitine L-tartrate supplementation in healthy men

The purpose of this investigation was to examine the effects of ingestion of L-CARNIPURE (L-carnitine L-tartrate [LCLT]) on alterations in a complete blood cell profile and in circulating metabolic enzymes. Using a balanced, placebo (P), cross-over design (1 week washout), 10 healthy, active men volunteered and acted as their own control taking either a P or LCLT supplement (3 g.day(-1)) for 3 weeks. Postabsorptive morning blood samples were obtained both before and after 21 days of P and LCLT supplementation. Serum samples were analyzed for clinical chemistries including a complete chemistry panel with markers of liver and renal function along with various minerals and electrolytes. In addition, whole blood was analyzed for a complete blood count with differential. It was determined that there were no statistically significant differences between the LCLT and the placebo conditions for any of the variables examined. The results of this study suggest that LCLT, when used as a dietary supplement, has no adverse effects on metabolic and hematological safety variables in normally healthy men.

Effects of a high-fat diet on postabsorptive and postprandial testosterone responses to a fat-rich meal

Postprandial testosterone concentrations have been shown to significantly decrease after a fat-rich meal, which may be due to inhibition of testosterone production by chylomicrons. We examined the effects of a high-fat diet known to reduce postprandial chylomicrons on the testosterone response to a fat-rich meal. Total testosterone (TT), free testosterone (FT), cortisol, and insulin responses to a high-fat test meal containing 5.44 MJ (1,300 kcal, 11% carbohydrate, 3% protein, 86% fat) were determined before (week 0) and after (week 8) an 8-week high-fat diet (64% fat) in 11 healthy men. The high-fat diet resulted in significant reductions in postabsorptive and postprandial serum triacylglycerols (55% and 50%, respectively). There were no significant changes in postabsorptive serum TT, FT, and cortisol, but insulin concentrations were significantly (P < or = .05) lower at week 8 (-28%). There was a significant reduction 1 hour after the fat-rich meal for TT (-22%) and FT (-23%), which remained significantly below baseline for 8 hours. Postprandial TT and FT responses were not significantly different after the 8-week high-fat diet. Postprandial serum cortisol concentrations were significantly reduced 1 hour after the meal. There were no significant differences before and after the high-fat diet. Insulin was significantly increased at the 0-, 1-, and 2-hour postprandial time points before and after the high-fat diet. Compared with week 0, insulin concentrations were significantly lower prior to and immediately after the fat-rich meal at week 8. These data indicate a fat-rich meal results in a prolonged reduction in TT and FT concentrations that is not altered by lowering postprandial chylomicrons. Alternative mechanisms (eg, higher uptake at the receptor level of cells) other than chylomicron-induced or insulin-induced inhibition of steroidogenesis are likely responsible for the reduction in TT and FT after a fat-rich meal.

Resistance training in patients with peripheral arterial disease: effects on myosin isoforms, fiber type distribution, and capillary supply to skeletal muscle

The purpose of this study was to investigate the effects of a progressive resistance training program on myosin heavy chain isoform expression, fiber type, and capillarization in patients with symptomatic peripheral arterial disease. Patients were randomized to either a training group (n = 11, mean +/- SD, 70 +/- 6 years, 4 men, 7 women) or a control group (n = 9, 66 +/- 6 years, 5 men, 4 women). The training sessions were completed 3 times/week, using 2 sets of various exercises, each performed for 8-15 repetitions. Muscle biopsies were obtained before and after 24 weeks from the medial gastrocnemius. Following the 24-week training program, the training group had significantly decreased the percentage of myosin heavy chain type IIB. The proportion of type IIB/AB fibers as measured by using myosin adenosine triphosphatase histochemistry decreased significantly in the training group. There were significant increases in type I and type II fiber areas, and capillary density also increased significantly in the training group. There were significant increases in 10 repetition maximum leg press and calf press strengths in the trained subjects. There were no significant changes in any of the measurements in the control group. It is concluded that progressive resistance training results in significant increases in muscle strength and alters skeletal muscle composition of subjects with peripheral arterial disease.

Changes in myosin heavy chain composition with heavy resistance training in 60- to 75-year-old men and women

The purpose of this investigation was to assess the myosin heavy chain (MHC) expression in the vastus lateralis muscle from elderly men and women, and to determine whether heavy resistance training influences its expression. Twenty healthy, mildly physically active subjects gave their informed consent to participate in the study. The experimental group consisted of seven men and seven women [mean (SD) age 65.5 (4.1) years] and the control group consisted of three men and three women [mean (SD) age 62.3 (3.6) years]. The 6-month resistance training program was divided into two phases with weeks 1-12 consisting of high-intensity resistance training, and weeks 13-24 involving power training. Muscle biopsy samples were taken from the vastus lateralis muscle at week 0 and week 24 using the needle biopsy technique. The male and female experimental groups both exhibited a significant decrease (P < or = 0.05) in the percentage of MHC IIb, while the experimental female group also demonstrated a significant increase (P < or = 0.05) in the expression of MHC IIa, after 24 weeks of heavy resistance training. There was no change in MHC expression within the control group. The male [130.4 (25.3) kg vs 171.1 (30.5) kg] and female [58.2 (8.3) kg vs 77.9 (11.1) kg] experimental groups exhibited a significant increase (P < or = 0.05) in the maximal strength values for the 1 repetition maximum (1RM) squat exercise. The control group showed no change in strength for the 1RM squat exercise for either the male [115.8 (35.10 kg vs 123.8 (47.2) kg] or female [57.5 (99.0) kg vs 58.3 (2.9) kg] groups. The results clearly show that elderly subjects undergoing heavy resistance training have the ability to produce a similar shift in the expression of MHC isoforms from MHC IIb to MHC IIa, as has been shown to occur in younger subjects. This highlights the plasticity of human skeletal muscle in response to heavy resistance training, even at older ages.