Physiological response to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups : metabolic rates, energy reserve utilization, and water fluxes

Physiological response to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups: metabolic rates, energy reserve utilization, and water fluxes. Am J Physiol Regul Integr Comp Physiol 297: R1582–R1592, 2009. First published September 23, 2009; doi:10.1152/ajpregu.90857.2008.— Surviving prolonged fasting requires various metabolic adaptations, such as energy and protein sparing, notably when animals are simultaneously engaged in energy-demanding processes such as growth. Due to the intermittent pattern of maternal attendance, subantarctic fur seal pups have to repeatedly endure exceptionally long fasting episodes throughout the 10-mo rearing period while preparing for nutritional independence. Their metabolic responses to natural prolonged fasting (33.4 ± 3.3 days) were investigated at 7 mo of age. Within 4–6 fasting days, pups shifted into a stage of metabolic economy characterized by a minimal rate of body mass loss (0.7%/day) and decreased resting metabolic rate  (5.9 ± 0.1 ml O₂ ·kg^-1·day^-1) that was only 10% above the level predicted for adult terrestrial mammals. Field metabolic rate (289 ± 10 kJ·kg^-1 ·day^-1) and water influx (7.9 ± 0.9 ml·kg^-1 ·day^-1) were also among the lowest reported for any young otariid, suggesting minimized energy allocation to behavioral activity and thermoregulation. Furthermore, lean tissue degradation was dramatically reduced. High initial adiposity (>48%) and predominant reliance on lipid catabolism likely contributed to the exceptional degree of protein sparing attained. Blood chemistry supported these findings and suggested utilization of alternative fuels, such as β-hydroxybutyrate and de novo synthesized glucose from fat-released glycerol. Regardless of sex and body condition, pups tended to adopt a convergent strategy of extreme energy and lean body mass conservation that appears highly adaptive for it allows some tissue growth during the repeated episodes of prolonged fasting they experience throughout their development.

Compensatory Ability to Null Mutation in Metabolic Networks

Robustness is an inherent property of biological system. It is still a limited understanding of how it is accomplished at the cellular or molecular level. To this end, this article analyzes the impact degree of each reaction to others, which is defined as the number of cascading failures of following and/or forward reactions when an initial reaction is deleted. By analyzing more than 800 organism’s metabolic networks, it suggests that the reactions with larger impact degrees are likely essential and the universal reactions should also be essential. Alternative metabolic pathways compensate null mutations, which represents that average impact degrees for all organisms are small. Interestingly, average impact degrees of archaea organisms are smaller than other two categories of organisms, eukayote and bacteria, indicating that archaea organisms have strong robustness to resist the various perturbations during the evolution process. The results show that scale-free feature and reaction reversibility contribute to the robustness in metabolic networks. The optimal growth temperature of organism also relates the robust structure of metabolic network.

Molecular depth profiling of organic and biological materials

Atomic depth profiling using secondary ion mass spectrometry, SIMS, is common in the field micro-electronics; however, the generation of molecular information as a function of sample depth is difficult due to the accumulation of damage both on and beneath the sample surface. The introduction of polyatomic ion beams such as SF₅ and C₆₀ have raised the possibility of overcoming this problem as they deposit the majority of their energy in the upper surface of the sample resulting in increased sputter yields but with a complimentary reduction in sub-surface damage accumulation. In this paper we report the depth profile analysis of the bio-polymer polycaprolactone, PCL, using the polyatomic ions Au₃⁺ and C₆₀⁺ and the monoatomic Au+. Results are compared to recent analysis of a similar sample using . depth profiling of cellulose is also demonstrated, an experiment that has been reported as unsuccessful when attempted with implications for biological analysis are discussed.

Nursing care of clients treated with atypical antipsychotics who have a risk of developing metabolic instability and/or type 2 diabetes

Objective : The aim of this article is to present a current discussion related to the nursing care of clients treated with atypical antipsychotic medicines and who have a risk of developing metabolic instability and/or Type 2 diabetes. The importance of such a discussion is to provide both the novice and the experienced nurse with additional knowledge of this current health issue with which to inform their nursing practice.

Discussion : The potential for psychosis to be a chronic condition is very high, and often people require antipsychotic medicine for lengthy periods throughout their lives. Sometimes, treatment is for life. The second generation of antipsychotic medicines was greeted with much enthusiasm since it was better tolerated than the first generation. However, each medication has desired and adverse effects and, when taken for lengthy periods, these effects may produce physical illness. Studies show that the prevalence of Type 2 diabetes and the metabolic syndrome was significantly higher in clients with a chronic psychiatric disorder, particularly schizophrenia.

Conclusions : Metabolic instability, especially weight gain, is associated with some psychotropic medicines. Nursing interventions need to include care assessment, planning, intervention, and evaluation for clients treated with antipsychotic medicines in terms of risk minimization strategies in routine nursing care.

Adiposity and its metabolic consequences contribute to Achilles tendinopathy

Pain in the Achilles tendon commonly affects active individuals but is also seen in sedentary people. This thesis shows that the accumulation of excess body fat, abnormal blood lipids and glucose metabolism were associated with Achilles tendinopathy. Targeting these lifestyle factors may improve treatment outcomes for tendon injury.

Profiling secondary metabolites of plant roots inoculated with Phytophthora cinnamomi

The soil-borne pathogen, Phytophthora cinnamomi, continues to cause severe dieback in Australian native forest species and is of great international significance due to its global distribution. This research established a protocol to successfully identify phyto-chemicals associated with the defense response of plants challenged by the disease caused by Phytophthora cinnamomi.

The ethical and policy implications of profiling 'vulnerable' customers

In the shadow of the global financial crisis, the issue of the marketing of credit has become an increasing concern in the past 12 months. Outstanding personal debt in the UK currently stands at £1479 billion and is rising by £1 million every 10.6 min. In Australia, there is currently $44.6 billion worth of outstanding credit card debt, and in the US, $2596 billion was owed on credit cards in 2008. At present, the banking sector utilizes sophisticated research methods to profile consumers, including those who might be considered financially vulnerable. However, the policy frameworks in most industrialized countries do not account for this form of target marketing when considering how to protect vulnerable groups. This paper is an initial attempt to examine the different methods by which profiling is conducted and the policy implications of this sophisticated form of segmentation and targeting. We argue that current consumer policies are inadequate in protecting vulnerable consumers from these marketing techniques, and recent recommendations from the Federal Reserve Bank of the United States, and the Australian Law Reform Commission to allow banks and lenders to ‘pre-screen’ potential customers will exacerbate personal debt levels, rather than reducing them.

Psychological profiling of Tasmanian police officers using the COPS

This thesis examined selection processes for police candidates, and the impact of police work on well-being. Results revealed that policing impacts negatively on psychological well-being over time, and that many aspects of the stereotypic 'police personality' are not a result of selection processes, but develop over time in the role.

The effect of resistance training on functional capacity and quality of life in individuals with high and low number of metabolic risk factors

OBJECTIVE—There are limited data on the effects of resistance training on the capacity to perform activities of daily living (ADLs) and quality of life (QoL) for individuals with a high number of metabolic risk factors (HiMF). In this study, we examined the effect of resistance training on the capacity to perform ADLs and QoL in individuals with HiMF and compared any benefits with individuals with a low number of metabolic risk factors (LoMF).

RESEARCH DESIGN AND METHODS—Fifty-five untrained individuals, aged 50.8 ± 6.5 years, were randomized to four groups: HiMF training (HiMFT), HiMF control, LoMF training (LoMFT), and LoMF control. At baseline and after 10 weeks of resistance training, participants underwent anthropometric measurements and assessments of aerobic power (Vo2peak), muscle strength, capacity to perform ADLs, and a self-perceived QoL questionnaire. A repeated-measures ANOVA was used to examine the effect of training over time among groups.

RESULTS—Training increased lean body mass in both HiMFT (P = 0.03) and LoMFT (P = 0.03) groups. Total fat content and Vo2peak improved in the LoMFT group only. Muscle strength improved in both training groups (P < 0.01). Time to complete ADLs was reduced by 8.8% in the LoMFT group (P < 0.01) and 9.7% in the HiMF group (P < 0.01). Only the HiMFT group reported improvement in QoL.

CONCLUSIONS— Resistance training improved muscle strength and the capacity to perform ADLs in individuals with HiMF and LoMF. Resistance training improved QoL for the HiMF group, and this result was independent of changes in body fat content or aerobic power. Longer training regimens may be needed to improve QoL in individuals with LoMF.

Functional capacity and quality of life in middle-age men and women with high and low number of metabolic risk factors

It is not clear if men and women with high numbers of risk factors (HiMF) for metabolic syndrome (MetS) have impaired capacities to perform activities of daily living (ADL's) and lower quality of life (QoL) in the absence of symptomatic heart disease. Our results indicate that in women there is a correlation between the number of risk factors and the capacity to perform ADL's and QoL. This was not evident for men. These findings may partly explain why women tend to consult healthcare practitioners earlier in the disease process than men.

BDNF, metabolic risk factors, and resistance training in middle-aged individuals

Introduction and Purpose: Brain-derived neurotrophic factor (BDNF) and physical inactivity contribute to the development of the metabolic syndrome (MetS). There appears to be an association between BDNF and risk factors for MetS, and the effects of resistance training (RT) on BDNF and metabolic risk in middle-aged individuals with high and low numbers of metabolic risk factors (HiMF and LoMF, respectively) are unclear and are the focus of this research.

Methods: Forty-nine men (N = 25) and women (N = 24) aged 50.9 ± 6.2 yr were randomized to four groups, HiMF training (HiMFT), HiMF control (HiMFC), LoMF training (LoMFT), and LoMF control (LoMFC). Before and after 10 wk of RT, participants underwent tests for muscle strength and anthropometry, and a fasting blood sample was taken. Data were analyzed using Spearman correlations and repeated-measures ANOVA.

Results: BDNF was positively correlated with plasma triglycerides, glucose, HbA1C, and insulin resistance. BDNF was elevated in HiMF compared with LoMF (904.9 ± 270.6 vs 709.6 ± 239.8 respectively, P = 0.01). Training increased muscle strength and lean body mass but had no effect on BDNF levels or any examined risk factors.

Conclusion: BDNF levels correlated with risk factors for MetS and were elevated in individuals with HiMF. RT had no effect on BDNF levels or other risk factors for MetS. As RT has an effect on muscle strength and lean body mass, it should be added to other nonpharmacological interventions for middle-aged individuals with HiMF such as aerobic and/or diet.

Inflammation, hepatic enzymes and resistance training in individuals with metabolic risk factors

Aims Increases in inflammatory markers, hepatic enzymes and physical inactivity are associated with the development of the metabolic syndrome (MetS). We examined whether inflammatory markers and hepatic enzymes are correlated with traditional risk factors for MetS and studied the effects of resistance training (RT) on these emerging risk factors in individuals with a high number of metabolic risk factors (HiMF, 2.9 ± 0.8) and those with a low number of metabolic risk factors (LoMF, 0.5 ± 0.5).

Methods Twenty-eight men and 27 women aged 50.8 ± 6.5 years (mean ± sd) participated in the study. Participants were randomized to four groups, HiMF training (HiMFT), HiMF control (HiMFC), LoMF training (LoMFT) and LoMF control (LoMFC). Before and after 10 weeks of RT [3 days/week, seven exercises, three sets with intensity gradually increased from 40–50% of one repetition maximum (1RM) to 75–85% of 1RM], blood samples were obtained for the measurement of pro-inflammatory cytokines, C-reactive protein (CRP), -glutamyltransferase (GGT) and alanine aminotransferase (ALT).

Results At baseline, HiMF had higher interleukin-6 (33.9%), CRP (57.1%), GGT (45.2%) and ALT (40.6%) levels, compared with LoMF (all P < 0.05). CRP, GGT and ALT correlated with the number of risk factors (r = 0.48, 0.51 and 0.57, respectively, all P < 0.01) and with other anthropometric and clinical measures (r range from 0.26 to 0.60, P < 0.05). RT did not significantly alter inflammatory markers or hepatic enzymes (all P > 0.05).

Conclusions HiMF was associated with increased inflammatory markers and hepatic enzyme concentrations. RT did not reduce inflammatory markers and hepatic enzymes in individuals with HiMF.

Akt, AS160, metabolic risk factors and aerobic fitness in middle-aged women

This study investigated the association between the basal (rest) insulin-signaling proteins, Akt, and the Akt substrate AS160, metabolic risk factors, inflammatory markers and aerobic fitness, in middle-aged women with varying numbers of metabolic risk factors for type 2 diabetes. Methods: Sixteen women (n=16) aged 51.3±5.1 (mean ±SD) years provided muscle biopsies and blood samples at rest. In addition, anthropometric characteristics and aerobic power were assessed and the number of metabolic risk factors for each participant was determined (IDF criteria). Results: The mean number of metabolic risk factors was 1.6±1.2. Total Akt was negatively correlated with IL-1β (r = -0.45, p = 0.046), IL-6 (r = -0.44, p = 0.052) and TNF-α (r = -0.51, p = 0.025). Phosphorylated AS160 was positively correlated with HDL (r = 0.58, p= 0.024) and aerobic fitness (r = 0.51, p=0.047). Furthermore, a multiple regression analysis revealed that both HDL (t=2.5, p=0.032) and VO_2peak (t=2.4, p=0.037) were better predictor for phosphorylated AS160 than TNF-α or IL-6 (p>0.05). Conclusions: Elevated inflammatory markers and increased metabolic risk factors may inhibit insulin-signaling protein phosphorylation in middle-aged women, thereby increasing insulin resistance under basal conditions. Furthermore, higher HDL and fitness levels are associated with an increase AS160 phosphorylation, which may in turn reduce insulin resistance.