Impact of 12 weeks of basic military training on testosterone and cortisol responses.

INTRODUCTION: Military personnel train and operate in challenging multistressor environments, which can affect hormonal levels, and subsequently compromise performance and recovery. The aims of this project were to evaluate concentrations of cortisol and testosterone and subjective perceptions of stress and recovery across basic military training (BMT). METHODS: 32 male recruits undergoing BMT were tracked over a 12-week course. Saliva samples were collected weekly, on waking, 30 min postwaking and bedtime. Perceptions of stress and recovery were collected weekly. Daily physical activity (steps) were measured via wrist-mounted accelerometers across BMT. Physical fitness was assessed via the multistage fitness test and push-ups in weeks 2 and 8. RESULTS: Concentrations of testosterone and cortisol, and the testosterone:cortisol ratio changed significantly across BMT, with variations in responses concurrent with programmatic demands. Perceptions of stress and recovery also fluctuated according to training elements. Recruits averaged 17 027 steps per day between weeks 2 and 12, with week-to-week variations. On average, recruits significantly increased predicted VO2max (3.6 (95% CI 1.0 to 6.1) mL/kg/min) and push-ups (5. 5 (95% CI 1.4 to 9.7) repetitions) between weeks 2 and 8. CONCLUSIONS: Recruit stress responses oscillated over BMT in line with programmatic demands indicating that BMT was, at a group level, well-tolerated with no signs of enduring physiological strain or overtraining. The sensitivity of cortisol, testosterone and the testosterone:cortisol ratio to the stressors of military training, suggest they may have a role in monitoring physiological strain in military personnel. Subjective measures may also have utility within a monitoring framework to help ensure adaptive, rather than maladaptive (eg, injury, attrition), outcomes in military recruits.

Does amantadine maintain function in long-established brain injury? A single case experimental design.

OBJECTIVE: The role of dopamine agonist (DA) in restoring consciousness and cognition in recovery phase following acquired brain injury (ABI) is established (1-5). The role in later recovery is less well defined. We report a single case experimental design (SCED) trial of amantadine demonstrating improvement in function, six years following ABI. METHOD: A scoring system based on established abilities in personal care and interaction was used to identify tasks with component actions, 34 actions in total, each ranked in terms of quality of response to a request or prompt. Actions were scored on maintenance dose amantadine; on withdrawal; and after reintroduction. Daytime sleep duration was also recorded. RESULTS: At 3rd and 5th weeks post withdrawal, deterioration was noted in 27 of 34 graded activities. At 3rd and 5th weeks following reintroduction, all but 3 grades returned to baseline or better. Afternoon sleep duration increased from 35 to 80 minutes during withdrawal period returning towards baseline on amantadine resumption. CONCLUSION: We believe this provides evidence for benefit of amantadine in sustaining function following ABI. The SCED model used provides a template for others to use to identify comparable change in similar trials.

Training distress and performance readiness: laboratory and field validation of a brief self-report measure.

Three studies were conducted to validate the Training Distress Scale (TDS), a 19-item measure of training-related distress and performance readiness. Study 1 was a randomized, controlled laboratory experiment in which a treatment group undertook daily interval training until a 25% decrement occurred in time-to-fatigue performance. Comparisons with a control group showed that TDS scores increased over time within the treatment group but not in the control group. Study 2 was a randomized, controlled field investigation in which performance capabilities and TDS responses were compared across a high-intensity interval training group and a control group that continued normal training. Running performance decreased significantly in the training group but not in the control group, and scores on the TDS mirrored those changes in performance capabilities. Study 3 examined the relationship between TDS scores obtained over a 2-week period before major swimming competitions and subsequent performance in those competitions. Significantly, better performance was observed for swimmers with low TDS scores compared with those with moderate or high TDS scores. These findings provide both laboratory and field evidence for the validity of the TDS as a measure of short-term training distress and performance readiness.

Training patterns and negative health outcomes in triathlon: longitudinal observations across a full competitive season.

AIM: Despite heavy training requirements, triathlon is a sport that is rapidly increasing in popularity. Yet, there is limited research detailing the relationship between training, the incidence of injuries and illness, psychological stress, overtraining and athlete burnout amongst triathletes. Six hypotheses relating inter-individual differences to training factors were generated to evaluate change in self-reported measures of these negative health outcomes over a training year. METHODS: Thirty, well-trained, triathletes (males n=20: age=27.1±9.1 years and females n=10: age=27.4±6.6 years) from a local triathlon club participated in this study. The study commenced during pre-season training, and involved weekly monitoring of each athlete until the end of the competitive season 45 weeks later. Linear Mixed Modelling was used for the analysis. RESULTS: Signs and symptoms of injury and illness (SAS) were significantly associated with increases in training factors (P≤0.05); however, greatest impact on SAS was produced by psychological stressors (P≤0.001). Common symptoms of overtraining were significantly affected by increases in exposure to both training and psychological stressors (P≤0.05). Mood disturbance was not significantly affected by training factors (P>0.05) but rather increases in psychological stressors (P≤0.001). Finally, each of the three athlete burnout subscales were significantly affected by both psychological (P≤0.001) stressors as well as varying combinations of training factors (P≤0.05). CONCLUSIONS: Exposure to stressors (either training or psychological) had significant effects on all negative health outcomes assessed.

Characterisation and protein expression profiling of annexins in colorectal cancer.

The annexins are family of calcium-regulated phospholipid-binding proteins with diverse roles in cell biology. Individual annexins have been implicated in tumour development and progression, and in this investigation a range of annexins have been studied in colorectal cancer. Annexins A1, A2, A4 and A11 were identified by comparative proteomic analysis to be overexpressed in colorectal cancer. Annexins A1, A2, A4 and A11 were further studied by immunohistochemistry with a colorectal cancer tissue microarray containing primary and metastatic colorectal cancer and also normal colon. There was significant increase in expression in annexins A1 (P=0.01), A2 (P<0.001), A4 (P<0.001) and A11 (P<0.001) in primary tumours compared with normal colon. There was increasing expression of annexins A2 (P=0.001), A4 (P=0.03) and A11 (P=0.006) with increasing tumour stage. An annexin expression profile was identified by k-means cluster analysis, and the annexin profile was associated with tumour stage (P=0.01) and also patient survival. Patients in annexin cluster group 1 (low annexin expression) had a better survival (log rank=5.33, P=0.02) than patients in cluster group 2 (high annexins A4 and A11 expression). In conclusion, this study has shown that individual annexins are present in colorectal cancer, specific annexins are overexpressed in colorectal cancer and the annexin expression profile is associated with survival.

Technical note: protein conjugate-based immunoassay of whole milk progesterone.

The objectives were to develop a novel protein conjugate-based ELISA test for whole milk progesterone with a dynamic range capable of fully profiling estrous cycles in the dairy cow and to study effects of whole milk medium on antibody binding to progesterone-protein conjugates. A series of progesterone-4-ovalbumin conjugates with different length intermediate linkers were applied as coating antigens in an ELISA format to determine antibody-binding performance in whole milk. Use of an 18-atom linker gave higher binding than use of a 4- or 11-atom linker at certain conjugate concentrations, but no further increase was observed with increasing linker length. An ELISA constructed with the 18-atom linker conjugate gave a detection limit of 0.089 ng/mL progesterone and correlated well to an established radioimmunoassay procedure (r = 0.94). The assay has the distinct advantages of a wide linear range (0.1 to 100 ng/mL), allowing full profiling of bovine estrous cycles, use of whole milk directly without extraction or prior dilution, and employing more easily purified protein conjugates as coating antigens compared with commercial progesterone-enzyme conjugate for milk ELISA assays.

Cholesteryl ester transfer protein reaction between plasma lipoproteins.

The rate of the non-directional transfer of cholesteryl ester and triglyceride by human cholesteryl ester transfer protein (CETP) was measured between human plasma lipoproteins by monitoring fluorescence spectrum of pyrene-labeled lipid. The transfer rates between high density lipoproteins (HDLs) and between low density lipoproteins (LDLs) were both directly proportional to the substrate lipid concentration within the physiological range of the lipoprotein concentration. Higher preference of cholesteryl ester transfer to triglyceride was demonstrated with HDL than LDL. Although the highly selective binding of CETP to HDL was observed in the electrophoretic analysis, the transfer rate was only moderately higher with HDL for cholesteryl ester and not so at all for triglyceride. In addition, the rate of cholesteryl ester transfer between LDLs was uninfluenced by the presence of a small amount of HDL that is just sufficient to absorb all the CETP in the reaction mixture. The results indicated the preferential transfer of cholesteryl ester over triglyceride by CETP in the interaction with HDL in non-directional lipid transfer reaction among lipoproteins. However, the apparent binding of CETP to HDL does not seem to play an essential role in this type of lipid transfer by CETP.

Activation of human plasma cholesteryl ester transfer protein by human apolipoprotein A-IV.

Function of apolipoprotein (apo) A-IV was studied for its role in cholesteryl ester transfer protein (CETP; lipid transfer protein, LTP) reaction between lipid microemulsions having the diameter of low density lipoprotein, being compared to apoA-I. CETP hardly catalyzed lipid transfer without apolipoproteins. ApoA-IV bound to the surface of the microemulsion in equilibrium with a similar affinity to that of other helical apolipoproteins, and activated the transfer reaction by CETP of cholesteryl ester, triacylglycerol and phosphatidylcholine between the emulsions. The rate of the transfer reaction of cholesteryl ester and triacylglycerol was directly proportional to the amount of the bound apoA-IV to the surface of the emulsion. For phosphatidylcholine, activation was less effective until 40% of total binding capacity of lipid emulsion was occupied by the apolipoprotein. Cholesteryl ester was highly preferred by CETP over triacylglycerol when equal amount of these lipids was present in the core of the apoA-IV-activated emulsion, resulting in almost no triacylglycerol transfer. However, when the emulsion has the core exclusively of triacylglycerol, triacylglycerol was transferred by CETP with the rate in the same order as that of cholesteryl ester transfer. These findings were all comparable to the results with apoA-I, and also consistent with our previous observation for other amphiphilic helical apolipoproteins such as apoA-II, E and C-III.

Cortisol alters gene expression during involution of the rat ventral prostate.

The ability of high doses of cortisol to retard the involution process in the rat ventral prostate was related to alterations in the pattern of gene expression. Poly(A)+ RNA preparations from the prostates of noncastrated, castrated, and castrated rats injected daily for 7 days with cortisol were compared by Northern blot hybridizations for the relative expression of genes associated with cell differentiation and maintenance (the C1 prostatic steroid binding protein gene and alpha-tubulin), with cell death (TRPM-2, hsp 70, and c-fos), and with hormone regulation (the androgen and glucocorticoid receptors). As anticipated, the concentration of C1 mRNA in the prostate fell to less than 4% of that in the noncastrated controls within 4 days after castration and was nearly undetectable after 7 days. This decline was retarded by cortisol treatment of 7-day castrated animals which sustained the level of C1 transcripts at approximately 50% of control. While the pattern of expression of alpha-tubulin indicated some minor fluctuations, with the highest level occurring 7 days after castration, the prostates of the cortisol-treated group had essentially the same concentration of this mRNA as the noncastrates. Cortisol also modified the expression of genes associated with prostatic cell death. The large increase in prostatic TRPM-2 mRNA, seen 7 days after castration, was reduced by over 80% after treatment with the glucocorticoid. Although not as abundantly expressed as TRPM-2, the castration-induced levels of transcripts for both hsp 70 and the protooncogene c-fos were substantially reduced by cortisol.(ABSTRACT TRUNCATED AT 250 WORDS)