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Dietary fish oil, providing docosahexaenoic acid (DHA) modulates oxygen consumption and fatigue in animal models. However, in humans predominately supplemented with high eicosapentaenoic acid (EPA), there is no evidence of endurance performance enhancement. Therefore, this study examined if DHA-rich fish oil could improve repeated bouts of physiologically stressful cycling and a subsequent time trial in a state of fatigue. Twenty-six trained males took part in a double-blind study and were supplemented with either 2 x 1g/day soy oil, Control) or DHA-rich tuna fish oil (Nu-Mega) (FO) (560mg DHA / 140mg eicosapentaenoic acid (EPA), for 8 weeks. Maximal cycling power (3 X 6s), isometric quadriceps strength (MVC), Wingate cycling protocol (6 x 30s) and a 5min cycling time-trial were assessed at baseline and eight weeks. The Omega-3 Index was not different at baseline (Control: 4.2 ± 0.2; FO: 4.7 ± 0.2%) and increased in the FO group after eight weeks (Control: 3.9 ± 0.2; FO: 6.3 ± 0.3%, p < .01). There was no effect of DHA-rich fish oil on power output of maximal 6s cycle sprinting (Control: pTe 1100 ± 49 Post 1067 ± 51; FO: Pre 1070 ± 46 Post 1042 ± 46W), during 5min time trail (Control: Pre 267 ± 19 Post 278 ± 20; FO: Pre 253 ± 16 Post 265 ± 16 W) or maximal voluntary contraction force (Control: Pre 273 ± 19 Post 251 ± 19; FO: Pre 287 ± 17 Post 283 ± 16 Nm). Nevertheless, relative oxygen consumption was reduced the FO group during the cycling time trial (Control: -23 ± 26; FO: -154 ± 59ml O2/min/100W p < .05) suggesting improved economy of cycling. We conclude that DHA-rich fish oil, successful at elevating the Omega-3 Index, and reflective of skeletal muscle membrane incorporation, can modulate oxygen consumption during intense exercise. [ABSTRACT FROM AUTHOR]

This study described the whole blood fatty acid profile and Omega-3 Index (O3I) of Australian Army recruits at the commencement and completion of basic military training (BMT). Eighty males (17–34 y, 77.4 ± 13.0 kg, 43.5 ± 4.3 mL/kg/min) and 37 females (17–45 y, 64.3 ± 8.8 kg, 39.3 ± 2.7 mL/kg/min) volunteered to participate (N = 117). Whole blood samples of each recruit were collected using a finger prick in weeks 1 and 11 (n = 82) and analysed via gas chromatography for the relative proportions of each fatty acid (mean [95% confidence interval]). The macronutrient characteristics of the diet offerings was also determined. At commencement there was a low omega-3 status (sum of omega-3; 4.95% [4.82–5.07]) and O3I (5.03% [4.90–5.16]) and no recruit recorded an O3I >8% (desirable). The omega-6/omega-3 (7.04 [6.85–7.23]) and arachidonic acid/eicosapentaenoic acid (AA/EPA) (18.70 [17.86–19.53]) ratios for the cohort were also undesirable. The BMT mess menu provided a maximum of 190 mg/day of EPA and 260 mg/day of docosahexaenoic acid (DHA). The O3I of the recruits was lower by week 11 (4.62% [4.51–4.78], p < 0.05), the omega-6/omega-3 increased (7.27 [7.07–7.47], p < 0.05) and the AA/EPA remained elevated (17.85 [16.89–18.81]). In conclusion, Australian Army recruits' omega-3 status remained undesirable during BMT and deserves nutritional attention. Novelty: Australian Army recruits' Omega-3 Index, at the commencement of BMT, was reflective of the Western-style diet. The BMT diet offered minimum opportunity for daily EPA and DHA consumption. Every recruit experienced a further reduction of their Omega-3 Index during BMT. [ABSTRACT FROM AUTHOR]

We have developed, and herein describe, a simple, open-loop model in the rat, in which both skin and hypothalamic temperatures can be modified and clamped. A water-perfused thermode was positioned in the abdomen to drive hypothalamic temperature, and a water-perfused jacket was used to clamp skin temperature. These permitted the independent control of hypothalamic and skin temperatures. The former could be altered between 35 and 41°C whilst achieving an isothermal skin temperature clamp. Similarly, skin temperature could be modified between 22 and 42°C whilst hypothalamic temperature was clamped. Maximal hypothalamic heating and cooling rates were: 0.75 and -2.04°Ch-1100g-1. We are currently using this animal model to investigate how central thermosensitivity is affected via manipulations of hypothalamic cooling rates. [Copyright &y& Elsevier]

This pilot study sought to determine whether a low, supplemental intake of fish oil would raise the Omega‐3 Index (O3I) and improve physical fitness in healthy older adults. Participants (70 ± 3 years) were randomised to 2 g/day of either sunola oil (control; n = 8, 62.5% female) (1700 mg/day oleic acid) or docosahexaenoic acid (DHA)‐rich fish oil (FO; n = 9, 55.6% female) [delivering 560 mg/day DHA and 140 mg/day eicosapentaenoic acid (EPA)] for 16 weeks. The O3I, physical fitness, 400 m walking speed and heart rate (HR) parameters were assessed. O3I was increased after FO (mean ± SD, control: pre 6.1 ± 0.8, post 5.9 ± 0.6; FO: pre 6.0 ± 0.6, post 8.3 ± 1.2 p < 0.05). Mean lowest overnight HR (control: pre 58 ± 6, post 58 ± 6; FO: pre 55 ± 6, post 52 ± 6 bpm, p < 0.05) and mean HR during fast walking (control: pre 120 ± 6, post 124 ± 7; FO: pre 122 ± 6, post 115 ± 6 bpm, p < 0.01) were reduced in the FO group without a change in walking speed (control: pre 1.55 ± 0.17, post 1.58 ± 0.20; FO: pre 1.59 ± 0.15, post 1.59 ± 0.18 m/s), HR variability or physical fitness. The changes in lowest resting HR and fast walking HR significantly correlated (inversely) with the changes in O3I. This nutritional approach of providing dietary achievable DHA offers a potential opportunity to reduce cardiovascular strain during physical activity in the older adult. [ABSTRACT FROM AUTHOR]

Background: Epidemiological studies and randomised clinical trials (RCTs) report disparate findings in relation to omega-3 polyunsaturated fatty acids (n-3 PUFA) benefit for cardiac patients. With RCTs interpretation is potentially confounded by background n-3 PUFA intake. The goal of this pilot, small cohort, pre-surgical supplementation study was to evaluate postoperative atrial fibrillation (AF) and cardiac molecular expression profiles employing two data analysis approaches - by treatment randomisation and by stratification using measured n-3 PUFA.Methods: Patients (n=20) received 3g/day of fish or placebo oil (FO vs PO) in a double blind randomised protocol prior to elective coronary artery graft and valve surgery. Groups were matched for age, gender, and mean treatment duration (∼20 days). Resected atrial myocardium was sampled for assay of viability metabolic markers, and blood obtained for erythrocyte membrane lipid measurement.Results: There was substantial overlap of cell membrane n-3 PUFA content across PO and FO groups, and no group treatment effects on AF incidence or myocardial molecular marker levels were detected. In contrast, data stratification using membrane n-3 PUFA content (at 8% total membrane lipid) achieved significant separation of patients (by n-6:n-3 PUFA ratio), a significant differential cardiac expression of the marker peroxisomal proliferator-activated receptor, but no difference in AF incidence.Conclusions: This small n-3 PUFA case study demonstrates that the same cohort may yield differing findings when evaluated using randomisation or stratification approaches based on direct molecular measures in cell membranes. [ABSTRACT FROM AUTHOR]

The article focuses on building research capacity through a community-based project under the research and critical analysis (RCA) program. It states that RCA is a very important component of medical science curriculum which is a course of four years including a 12-month general practitioner (GP) placement in a rural, regional or remote community in New South Wales. Under the program, every student is required to undertake a research project on the basis of his or her placement community.

Clinically and experimentally, a case for omega-3 polyunsaturated fatty acid (PUFA) cardioprotection in females has not been clearly established. The goal of this study was to investigate whether dietary omega-3 PUFA supplementation could provide ischemic protection in female mice with an underlying genetic predisposition to cardiac hypertrophy. Mature female transgenic mice (TG) with cardiac-specific overexpression of angiotensinogen that develop normotensive cardiac hypertrophy and littermate wild-type (WT) mice were fed a fish oil-derived diet (FO) or PUFA-matched control diet (CTR) for 4 wk. Myocardial membrane lipids, ex vivo cardiac performance (in- traventricular balloon) after global no-flow ischemia and reperfusion (15/30 mm), and reperfusion arrhythmia incidence were assessed. FO diet suppressed cardiac growth by 5% and 10% in WT and TO, respectively (P < 0.001). The extent of mechanical recovery [rate- pressure product (RPP) = beats/mm X mmHg] of FO-fed WT and TG hearts was similar (50 ± 7% vs. 45 ± 12%, 30 mm reperfusion), and this was not significantly different from CTR-fed WT or TO. To evaluate whether systemic estrogen was masking a protective effect of the FO diet, the responses of ovariectomized (OVX) WT and TG mice to FO dietary intervention were assessed. The extent of mechanical recovery of FO-fed OVX WT and TO (RPP, 50 ± 4% vs. 64 ± 8%) was not enhanced compared with CTR-fed mice (RPP, 60 ± 11% vs. 80 ± 8%, P = 0.335). Dietary FO did not suppress the incidence of reperfusion arrhythmias in WT or TO hearts (ovary-intact mice or OVX). Our findings indicate a lack of cardioprotective effect of dietary FO in females, determined by assessment of mechanical and arrhythmic activity postischemia in a murine ex vivo heart model. [ABSTRACT FROM AUTHOR]

Long-chain omega-3 polyunsaturated fatty acid (LC n -3 PUFA) supplements, rich in eicosapentaenoic acid and/or docosahexaenoic acid, are increasingly being recommended within athletic institutions. However, the wide range of doses, durations and study designs implemented across trials makes it difficult to provide clear recommendations. The importance of study design characteristics in LC n -3 PUFA trials has been detailed in cardiovascular disease research, and these considerations may guide LC n -3 PUFA study design in healthy cohorts. This systematic review examined the quality of studies and study design considerations used in evaluating the evidence for LC n -3 PUFA improving performance in physically trained adults. SCOPUS, PubMed and Web of Science electronic databases were searched to identify studies that supplemented LC n -3 PUFA in physically trained participants. Forty-six ( n = 46) studies met inclusion. Most studies used a randomised control design. Risk of bias, assessed using the design-appropriate Cochrane Collaboration tool, revealed that studies had a predominant judgment of 'some concerns', 'high risk' or 'moderate risk' in randomised controlled, randomised crossover or non-randomised studies, respectively. A custom five-point quality assessment scale demonstrated that no study satisfied all recommendations for LC n -3 PUFA study design. This review has highlighted that the disparate range of study designs is likely contributing to the inconclusive state of outcomes pertaining to LC n -3 PUFA as a potential ergogenic aid. Further research must adequately account for the specific LC n -3 PUFA study design considerations, underpinned by a clear hypothesis, to achieve evidence-based dose, duration and composition recommendations for physically trained individuals.

Regular fish consumption, a rich source of long-chain omega-3 (ω-3) docosahexaenoic acid (DHA), modifies cardiac electrophysiology. However, human studies investigating fish oil and cardiac electrophysiology have predominantly supplemented therapeutic (high) doses of fish oil (often ω-3 eicosapentaenoic acid (EPA) rich sources). This study examined whether non-therapeutic doses of DHA-rich fish oil modulate cardiac electrophysiology at rest and during cardiovascular reflex challenges to the same extent, if at all, in young healthy adults., Participants (N = 20) were supplemented (double-blinded) with (2x1g.day -1 ) soy oil (Control n = 9) or DHA-rich tuna fish oil (FO n = 11) providing DHA: 560 mg and EPA: 140 mg. The Omega-3 Index (O3I; erythrocyte membrane % EPA + DHA), heart rate (HR) and HR variability (HRV) were analyzed during rest, maximal isometric handgrip and cold diving reflex challenges at baseline and following 8 weeks., The baseline O3I (Control: 5.1 ± 1.0; FO: 5.4 ± 0.9; P  > 0.05), resting HR (Control: 65 ± 12bpm; FO: 66 ± 8bpm; P  > 0.05) and HRV metrics did not significantly differ between the groups prior to supplementation. Relative to the control group, the O3I was increased (Control: 5.0 ± 1.1; FO: 7.8 ± 1.2; P  < 0.001), and resting HR was slowed in the FO group following supplementation (Control: 66 ± 9bpm; FO: 61 ± 6bpm; P =  0.046). However, no significant ( P  > 0.05) between-group differences were observed in HR responsiveness or any indices of HRV during reflex challenges., In young healthy adults, dietary achievable doses of ω-3 DHA-rich fish oil exerted a direct slowing effect on resting HR, without compromising the HR response to either dominant sympathetic or parasympathetic modulation.

Aims: Supplementing animal diets with high-dose fish oil, rich in long chain omega-3 (ω-3) docosahexaenoic acid (DHA), enhances cardiac contractile efficiency and attenuates dysfunction, attributable to ischaemia. However, it remains unclear whether smaller doses, equivalent to what is achievable via regular fish consumption in the human diet, offer similar protection., Methods: Male Sprague-Dawley (12-15w) rats were fed isoenergetic diets (ad libitum) containing 10% fat by weight (22% energy) for 4-5w. Control diet (CON) contained 5.5% beef tallow; 2.5% ω-6 sunflower seed oil; 2% olive oil. Fish oil diets included high-DHA tuna oil exchanged for olive oil to provide 0.32% (FO1; human equivalent EPA + DHA 570 mg/d) or 1.25% (FO2; equivalent EPA + DHA 2.3 g/d) wt/wt dose of fish oil. Anaesthetised rats (pentobarbital: 60 mg/kg i.p.) were subjected to 45 min coronary artery occlusion then reperfusion in vivo as a whole animal model of regional myocardial ischaemia, with left ventricular haemodynamic function measured by conductance catheter., Results: Ischaemia-induced reductions in rate pressure product recovered faster in the FO2 group and post-ischaemic left ventricular pressure-volume loop integrity (shifted downwards and right in CON) was partially protected in both fish oil groups., Conclusion: Ischaemia-induced contractile dysfunction in rats is limited from fish oil doses equivalent to regular consumption of fish in the human diet. These observations highlight plausible and clinically relevant physiological changes that rationalise nutritional conditioning of the heart with DHA for on-going cardioprotection., (© 2021. Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Supplementing animal diets with fish oil increases myocardial omega-3 polyunsaturated fatty acids [ω-3 (n-3) PUFA], lowers heart rate, and prevents malignant cardiac arrhythmias. In contrast to epidemiological reports, results of some human clinical trials and of unphysiologically high doses employed in animal studies call into question the application of dietary ω-3 PUFA for cardioprotection., Objective: This study tested the hypothesis that low ω-3 PUFA dietary thresholds for myocardial incorporation in rats, equivalent in dose to what humans derive from eating fish, can reduce heart rate and arrhythmia vulnerability., Methods: Male Sprague-Dawley rats (12-15 wk old) were fed isoenergetic diets containing 10% fat for 4-5 wk. The control diet (CON) contained 5.5% beef tallow, 2.5% sunflower seed oil, and 2% olive oil. Fish oil diets contained high-DHA tuna oil, exchanged for olive oil: 0.31% [fish oil group 1 (FO1)] (human equivalent EPA + DHA 570 mg/d); 1.25% [fish oil group 2 (FO2)] (equivalent EPA + DHA 2.3 g/d). Anaesthetized rats (pentobarbital, 60 mg/kg intraperitoneally) were subjected in vivo to 15-min cardiac ischemia by left coronary artery occlusion and then reperfusion, with arrhythmias detected by electrocardiogram., Results: Fish oil dose dependently modulated myocardial membrane fatty acids (DHA mean ± SEM: CON, 5.0 ± 0.2%; FO1, 13.1 ± 0.9%; FO2, 18.3 ± 0.4%; n = 4-5; P-trend < 0.001 ANOVA); resting heart rate (CON, 453 ± 6; FO1, 432 ± 4; FO2, 422 ± 5 bpm; n = 15-18; P-trend < 0.001); reduced ventricular fibrillation (VF) (CON, 89%; FO1, 60%; P = 0.052; FO2, 50%; n = 15-18; P = 0.013 chi square); and total arrhythmia severity (arrhythmia score: CON, 6.1 ± 0.4; FO1, 4.6 ± 0.5; FO2, 3.1 ± 0.7; n = 15-18; P-trend < 0.01) during ischemia and reperfusion (VF: Con, 86%; FO1, 22% P = 0.011; FO2, 8% P = 0.001; n = 7-12); (arrhythmia score: CON, 4.6 ± 0.3; FO1, 3.1 ± 0.3; FO2, 1.3 ± 0.3; n = 7-12; P-trend < 0.001)., Conclusions: Ventricular arrhythmias were prevented and heart rate was slowed by lower ω-3 PUFA intake in rats than previously reported, equivalent to human fish consumption and associated with increased myocardial DHA. The efficacy of low-dose fish oil demonstrates biological plausibility for nutritional ω-3 fatty acid-mediated cardioprotection and suggests that effectiveness in human clinical trials may be obscured by failure to exclude fish eaters., (Copyright © The Author(s) on behalf of the American Society for Nutrition 2020.)

Objectives: Heart rate variability (HRV) is often measured during clinical and experimental cardiovascular reflex tests (CRT), as a reflection of cardiac autonomic modulation, despite limited characterization of the rapid responses that occur. Therefore, we evaluated the responsiveness of HRV indices in 20 healthy young adults (age, 27 ± 6 y; mass, 76.9 ± 16.8 kg; height, 1.79 ± 0.12 m) during four separate established CRT., Methods: These included the [I] orthostatic challenge, [II] isometric handgrip, [III] cold pressor and [IV] cold diving reflex tests. Electrocardiogram was recorded throughout, with HRV derived from RR intervals at rest and from each CRT. On a separate day, a subgroup of participants (n=9) completed the same protocol for a second time., Results: The maximal slope of heart rate change (dTdt) was significantly different between all CRT, with the orthostatic challenge producing the fastest increase (2.56 ± 0.48) and the cold pressor the fastest reduction (-1.93 ± 0.68) in heart rate. Overall HRV, reflected by Poincaré plot ratio (SD1:SD2), was significantly reduced during all CRT ([I], -0.41 ± 0.12; [II], -0.19 ± 0.05; [III], -0.36 ± 0.12; [IV], -0.44 ± 0.11; p<0.05) relative to baseline and this was reproducible in time-series. However, when HRV indices were correlated to mean-RR an exponential growth-like relationship was evident (R 2 ranging from: 0.52-0.62)., Conclusions: These unique outcomes demonstrate that short-term alterations in HRV are evident during CRT, while indicating the importance of adjusting for, or at least reporting, underlying heart rate when interpreting such measures., (© 2020 Walter de Gruyter GmbH, Berlin/Boston.)

Background: Rock climbers are characterized by enhanced forearm fatigue resistance. This study compared the forearm isometric force of rock climbers (RC), strength-matched power lifters (PL) and aerobically trained (AT) athletes to determine the contribution of muscle oxygen desaturation during ischemia., Methods: Aerobically trained athletes (N.=6, 23±1 years, 77±1 kg), power lifters (N.=7, 24±1 years, 80±3 kg) and rock climbers (N.=8, 25±2 years, 74±2 kg) took part in a controlled forearm ischemic occlusion (5 min) assessment using near infrared spectroscopy. In addition, three fatigue protocols were completed: protocol 1, sustained maximal voluntary contraction (MVC) until exhaustion; protocol 2, sustained 40% MVC for 3 mins duration; protocol 3, an intermittent 40% MVC (5-s contraction, 5-s recovery) for a duration of 3 mins. Forearm contractile fatigue was quantified as the reduction in MVC., Results: MVC was equivalent between groups (P>0.05). Sustained MVC force (time to decline 50% MVC) was longer in the RC versus AT (AT: 35±5, PL: 46±6, RC: 54±4 s, P<0.05) and both AT and PL for sustained 40% MVC (AT: 56±9, RT: 62±8, RC: 87±7 s, P<0.05). Reduction in MVC was less in RC post intermittent 40% contractions (P<0.05). Oxygen desaturation half-time was longer in the RC versus AT (AT: 65±9, RT: 86±7, RC: 99±7 s, P<0.05) and this was associated with time to 50% MVC (P<0.05, r 2 =0.53) and time to 40% MVC task failure (P<0.05, r 2 =0.32)., Conclusions: Rock climbers' enhanced isometric fatigue-resistance and ability to maintain MVC was associated with a lower oxygen consumption of the forearm flexors during the ischemic state. This suggests a training adaptation involving intracellular oxygen consumption.

Background and Purpose- We hypothesized that total marine n-3 polyunsaturated fatty acids (PUFA), in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the diet and in adipose tissue (biomarkers of long-term intake and endogenous exposure) were inversely associated with the risk of ischemic stroke and its subtypes. Methods- The Diet, Cancer and Health cohort consisted of 57 053 participants aged 50 to 65 years at enrolment. All participants filled in a food frequency questionnaire and had an adipose tissue biopsy taken at baseline. Information on ischemic stroke during follow-up was obtained from The Danish National Patient Register, and all cases were validated. Cases and a random sample of 3203 subjects from the whole cohort had their fatty acid composition of adipose tissue determined by gas chromatography. Results- During 13.5 years of follow-up 1879 participants developed an ischemic stroke. Adipose tissue content of EPA was inversely associated with total ischemic stroke (hazard ratio [HR], 0.74; 95% CI, 0.62-0.88) when comparing the highest with the lowest quartile. Also, lower rates of large artery atherosclerosis were seen with higher intakes of total marine n-3 PUFA (HR, 0.69; 95% CI, 0.50-0.95), EPA (HR, 0.66; 95% CI, 0.48-0.91) and DHA (HR, 0.72; 95% CI, 0.53-0.99), and higher adipose tissue content of EPA (HR, 0.52; 95% CI, 0.36-0.76). Higher rates of cardioembolism were seen with higher intakes of total marine n-3 PUFA (HR, 2.50; 95% CI, 1.38-4.53) and DHA (HR, 2.12; 95% CI, 1.21-3.69) as well as with higher adipose tissue content of total marine n-3 PUFA (HR, 2.63; 95% CI, 1.33-5.19) and DHA (HR, 2.00; 95% CI, 1.04-3.84). The EPA content in adipose tissue was inversely associated with small-vessel occlusion (HR, 0.69; 95% CI, 0.55-0.88). Conclusions- EPA was associated with lower risks of most types of ischemic stroke, apart from cardioembolism, while inconsistent findings were observed for total marine n-3 PUFA and DHA.

We investigated the risk of ischemic stroke and its subtypes when red meat or poultry was substituted with fish. A total of 57,053 participants aged 50⁻65 years at baseline were included in the Danish Diet, Cancer and Health study. All participants filled in a food-frequency questionnaire at recruitment. Potential ischemic stroke cases were identified by linkage to the Danish National Patient Register, and all cases were validated and subclassified. Substitutions were investigated as 150 g/week of fish for 150 g/week of red meat or of poultry using multivariable Cox proportional hazard regression models. During 13.5 years of follow-up, 1879 participants developed an ischemic stroke. Replacing red meat or poultry with fish was not associated with the rate of total ischemic stroke, but there was a statistically significant lower rate of large artery atherosclerosis when fish replaced processed (hazard ratio (HR): 0.78; 95% confidence interval (CI): 0.67; 0.90) and unprocessed (HR: 0.87; 95% CI: 0.75; 0.99) red meat. A statistically significant higher rate of cardioembolism was found when poultry was replaced by total fish (HR: 1.42; 95% CI: 1.04; 1.93). When fatty fish replaced unprocessed red meat, a statistically significant lower rate of small-vessel occlusion was found (HR: 0.88; 95% CI: 0.77; 0.99). In conclusion, replacing red meat with fish was not associated with risk of total ischemic stroke but was associated with a lower risk of subtypes of ischemic stroke.

Introduction: Remote communities across Australia lack the ready access to medical care generally afforded to metropolitan populations. The Royal Flying Doctor Service (RFDS) medical chest program provides medical resources to these communities allowing medications to be dispensed in conjunction with a telehealth consulting service. More than 3000 medical chests are located throughout Australia and each year the Queensland RFDS conducts approximately 20 000 telehealth consultations. The aim of this study was to review the use of the medical chest model within the state of Queensland and to analyse changes in the medical chest program from 10 years earlier to evaluate the changing healthcare needs of remote Australian populations., Methods: All telehealth consultations and items dispensed from the medical chests were reviewed over a 1-year period from 1 July 2013 and 30 June 2014. Items dispensed were categorised and compared to those in 2005-06 in absolute terms by one-way ANOVA and proportionately by χ2 with Fisher's exact test. Consultations using the medical chest were categorised and compared to those in 2005-06 by χ2 with Fisher's exact test., Results: The number of telehealth consultations conducted in 2013-14 (N=20 707) was not different to the number conducted in 2005-06 (N=21 470). Fewer items were dispensed from the medical chests in 2013-14 (3936 total items) than in 2005-06 (8607 total items; p<0.0001). In the specific categories of 'burns and other dressings' and 'antihistamines', the number of individual items dispensed increased. Resources from the medical chest were used more for genitourinary system consultations and less for consultations involving specific infectious diseases; the circulation, respiratory and abdominal systems; skin diseases; injury; symptoms without a diagnosis; and following other contact with a health service., Conclusions: The medical chests remain a vital tool for medical care of remote populations and the need for telehealth medical advice remains unchanged, although fewer items are being dispensed. The use of the medical chest for each diagnostic category of consultation has shown some variation over the past 10 years, reflective of changing patterns of accident, injury and disease.

Reactive oxygen species paradoxically underpin both ischaemia/reperfusion (I/R) damage and ischaemic preconditioning (IPC) cardioprotection. Long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFA) are highly susceptible to peroxidation, but are paradoxically cardioprotective. This study tested the hypothesis that LCn-3 PUFA cardioprotection is underpinned by peroxidation, upregulating antioxidant activity to reduce I/R-induced lipid oxidation, and the mechanisms of this nutritional preconditioning contrast to mechanisms of IPC. Rats were fed: fish oil (LCn-3 PUFA); sunflower seed oil (n-6 PUFA); or beef tallow (saturated fat, SF) enriched diets for six weeks. Isolated hearts were subject to: 180 min normoxic perfusion; a 30 min coronary occlusion ischaemia protocol then 120 min normoxic reperfusion; or a 3 × 5 min global IPC protocol, 30 min ischaemia, then reperfusion. Dietary LCn-3 PUFA raised basal: membrane docosahexaenoic acid (22:6n-3 DHA); fatty acid peroxidisability index; concentrations of lipid oxidation products; and superoxide dismutase (MnSOD) activity (but not CuZnSOD or glutathione peroxidase). Infarct size correlated inversely with basal MnSOD activity (r² = 0.85) in the ischaemia protocol and positively with I/R-induced lipid oxidation (lipid hydroperoxides (LPO), r² = 0.475; malondialdehyde (MDA), r² = 0.583) across ischaemia and IPC protocols. While both dietary fish oil and IPC infarct-reduction were associated with reduced I/R-induced lipid oxidation, fish oil produced nutritional preconditioning by prior LCn-3 PUFA incorporation and increased peroxidisability leading to up-regulated mitochondrial SOD antioxidant activity.

Reduced cardiac mortality and morbidity have long been observed in association with omega-3 long chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish consumption, without clear physiological explanation. This review seeks to identify mechanisms of action based on evidence: of physiological effects, active components and effective intakes. Fish oil pleiotropic effects reveal actions that are either intrinsic: effects on cardiac function dependent upon membrane incorporation; or extrinsic: indirect cardiac effects through vascular disease. Extrinsic actions require EPA + DHA doses >3 g/day. Intrinsic effects derive from usual dietary intakes, <1 g/day and include improved myocardial oxygen efficiency, heart rate, nutritional preconditioning against ischaemic injury, arrhythmias and heart failure. Myocardial Na(+) and K(+) currents are non-selectively modulated by omega-3 and omega-6 PUFA to stabilise cells in vitro, but not by fish oil-induced membrane change. In contrast, cellular Ca(2+) overload involved in ischaemic injury, arrhythmia and spontaneous pacemaker activity are modulated by both dietary fish oil and in vitro omega-3 LC-PUFA. A potential linking role of bioactive epoxy and hydroxy PUFA derivatives requires investigation. Omega-3 DHA predominates over EPA in population intake, is preferentially incorporated into myocardium and is selectively active in heart rate and arrhythmia modulation, but EPA predominates in clinical trials. Myocardial selectivity for DHA and independent intrinsic and extrinsic physiological mechanisms underpinning diverse clinical endpoints can explain some contradictory outcomes of clinical trials. Intrinsic modulation of intracellular Ca(2+) handling provides a unifying physiologically plausible basis for intrinsic fish oil actions and insight to nutritional optimisation of cardiac function.

Thermally induced eccrine sweating is cholinergically mediated, but other neurotransmitters have been postulated for psychological (emotional) sweating. However, we hypothesized that such sweating is not noradrenergically driven in passively heated, resting humans. To test this, nine supine subjects were exposed to non-thermal stimuli (palmar pain, mental arithmetic and static exercise) known to evoke sweating. Trials consisted of the following four sequential phases: thermoneutral rest; passive heating to elevate (by ~1.0°C) and clamp mean body temperature and steady-state sweating (perfusion garment and footbath); an atropine sulphate infusion (0.04 mg kg(-1)) with thermal clamping sustained; and following clamp removal. Sudomotor responses from glabrous (hairless) and non-glabrous skin surfaces were measured simultaneously (precursor and discharged sweating). When thermoneutral, these non-thermal stimuli elicited significant sweating only from the palm (P < 0.05). Passive heating induced steady-state sweating ranging from 0.20 ± 0.04 (volar hand) to 1.40 ± 0.14 mg cm(-2) min(-1) (forehead), with each non-thermal stimulus provoking greater secretion (P < 0.05). Atropine suppressed thermal sweating, and it also eliminated the sudomotor responses to these non-thermal stimuli when body temperatures were prevented from rising (P > 0.05). However, when the thermal clamp was removed, core and skin temperatures became further elevated and sweating was restored (P < 0.05), indicating that the blockade had been overcome, presumably through elevated receptor competition. These observations establish the dependence of both thermal and non-thermal eccrine sweating from glabrous and non-glabrous surfaces on acetylcholine release, and challenge theories concerning the psychological modulation of sweating. Furthermore, no evidence existed for the significant participation of non-cholinergic neurotransmitters during any of these stimulations.

Objective: The sustainability of community-based medical education relies on maintaining consultation quality as perceived by patients. This study aims to investigate the effect of an alternative model (parallel consultation) of teaching on patients' views of consultation quality as compared to the conventional consultation model in a general practice setting., Design: A cross-sectional questionnaire study., Setting and Participants: Patients attending a regional general practice in the Southern Highlands of New South Wales between February and May 2010, who consented to student involvement in their consultation., Main Outcome Measures: Instruments to measure 'empathy' (CARE score) and 'enablement' (PEI score) as markers for consultation quality were administered after patient consultations., Results: There was no difference in consultation length between the two groups. There was a small increase in the level of empathy experienced by patients attending parallel consultations compared to conventional consultations (P<0.05). The level of enablement did not differ between the groups. Although generally encouraging towards student involvement, patients' attitudes were significantly more positive towards students involved in the parallel consultation group (P<0.01)., Conclusions: There is no loss in consultation quality, as experienced by the patient, when using the parallel consulting model. Parallel consulting does not change the length of time a patient spends with their doctor, and patients have a positive perception of the students involved in this model of clinical teaching.

Long chain n-3 PUFA docosahexaenoic acid (DHA) is important for heart and brain function. Investigations of biologically plausible mechanisms using animal models associate cardioprotection with DHA incorporation into myocardial membranes that are largely derived from supra-physiological fish oil (FO) intake. We measured the incorporation of DHA into myocardial membranes of rats from low dietary FO intake within human dietary range and quantitatively assessed the influence of dietary n-6 PUFA. With rats fed diets containing 0.16%-5% FO, equal to 0.12%-8.7% energy (%en) as eicosapentaenoic acid (EPA) and DHA (EPA+DHA), and either 1.5%en or 7.5%en n-6 PUFA (linoleic acid) for four weeks, dietary n-6:n-3 PUFA ratios ranged from 74 to 0.3. Myocardial DHA concentration increased in a log-linear fashion with a dietary threshold of 0.019%en as EPA+DHA and half maximal dietary [EPA+DHA] equal to 0.29%en (95% CI, 0.23-0.35). Dietary linoleic acid intake did not influence myocardial DHA. Myocardial membranes are sensitive to absolute dietary intake of long chain n-3 PUFA at low %en in the rat, equivalent to a human intake of one meal of fatty fish per week or less. The dietary ratio of n-6:n-3 PUFA has no influence on long chain n-3 PUFA cellular incorporation from dietary fish oil.

Fish oil (FO) modifies cardiac membrane phospholipid fatty acid composition to confer increased efficiency of oxygen utilization and antiarrhythmic effects. We tested the capacity of low-dose increments of FO, rich in (n-3) PUFA, to reverse the detrimental pro-arrhythmic and inefficient oxygen usage effects of dietary saturated fat (SAT) [including high ratio of (n-6) PUFA:(n-3) PUFA] during ischemia and reperfusion. Wistar rats were fed an SAT-enriched diet (15.3% fat, including 12% SAT, added by weight) for 6 wk and were then divided into 4 groups (n = 10/group) fed that diet or a 12% fat diet containing 3, 6, or 12% FO in place of SAT for 6 wk. Paced (300/min), erythrocyte-perfused isolated working hearts were subjected to low coronary flow ischemia (15 min) and were then reperfused. At normoxic baseline, external work capacity increased marginally at 6 and 12% FO; however, marked dose-related reductions in oxygen consumption were evident due to FO-dependent reduction in oxygen-energy utilization efficiency and associated reductions in coronary flow and oxygen extraction. Postischemic recovery resulted in lower oxygen consumption, greater oxygen-energy utilization efficiency, reduced coronary release of creatine kinase, and reduced incidence of arrhythmias in all FO groups compared with the SAT group. FO at a dose as low as 3% of total fat dietary supplement effectively reversed the high oxygen requirements and pro-arrhythmic effects of a SAT-rich diet even with continued consumption of SAT (9%) in this ex vivo animal model.

Fish consumption is associated with reduced cardiovascular mortality, and elevated myocardial long-chain n-3 polyunsaturated FA (PUFA) content is implicated in this cardioprotection. This study examined the dose and time responses for incorporation of n-3 PUFA into cellular membranes in rats fed fish oil (FO)-containing diets. For the time course study, rats were fed a 10% FO diet for periods ranging from 0 to 42 d, after which myocardial and erythrocyte membrane fatty acid composition was determined. For the dose response study, rats (n = 3) were fed 0, 1.25, 2.5, 5, or 10% FO for 4 wk, with myocardial, erythrocyte, and skeletal muscle membrane FA determined. Myocardial DHA (22:6n-3) levels doubled in 2 d, stabilizing at levels approximately 200% higher than control after 28 d feeding with 10% FO. By comparison, DHA levels doubled after 4 wk of 1.25% FO feeding. In myocardium and skeletal muscle, EPA (20:5n-3) levels remained low, but in erythrocytes EPA levels reached 50% of DHA levels. The n-3 PUFA were incorporated at the expense of n-6 PUFA in myocardium and skeletal muscle, whereas erythrocytes maintained arachidonic acid levels, and total n-3 PUFA incorporation was lower. This study shows that low doses of FO produce marked changes in myocardial DHA levels; maximal incorporation takes up to 28 d to occur; and while erythrocytes are a good indicator of tissue n-3 incorporation in stable diets, they vary greatly in their time course and pattern of incorporation.