The influence of post-exercise macronutrient intake on energy balance and protein metabolism in active females participating in endurance training

The purpose of this investigation was to determine the influence of post-exercise macronutrient intake on weight loss, protein metabolism, and endurance exercise performance during a period of increased training volume. Ten healthy young female endurance athletes performed 4 60-min bouts of cycle ergometry at approximately 65% of VO2peak on 4 days (day 1, 3, 4, and 6) during 2 separate 1-week periods. On day 7, participants performed a ride to exhaustion at approximately 75% of VO2peak. One of the 7-day periods served as a control condition, where a placebo beverage was consumed following the exercise bouts on days 1, 3, 4, and 6 (CON). During the other 7-day protocol (POST), participants consumed a predefined formula beverage with added carbohydrate following the exercise bouts on days 1, 3, 4, and 6. Energy intake and macronutrient proportions were the same between the 2 trials; the only difference was the timing at which the macronutrients were consumed. Calculated fat oxidation was greater during exercise on day 6 during POST as compared to CON (p < .05). Glucose and insulin concentrations were significantly higher (p < .05) following exercise during POST as compared to CON. There was a trend (p = .06) for nitrogen balance to be greater on days 5 and 6 with POST as compared to CON. Time to exhaustion during exercise on day 7 was longer during POST as compared to CON (p < .05). POST resulted in a maintenance of body weight during the 7-day protocol, while there was a significant (p < .05) reduction with CON. It was concluded that post-exercise macronutrient intake following endurance exercise can attenuate reductions in body weight and improve nitrogen balance during 7 days of increased energy expenditure. Importantly, post-exercise supplementation improved time to exhaustion during a subsequent bout of endurance exercise.     

Characteristics of HIV patients who attempt suicide

OBJECTIVE: To examine the risk factors for suicidal behaviour in human immunodeficiency virus (HIV) positive patients. METHOD: HIV substance dependent positive patients who had attempted suicide were compared with HIV substance dependent positive patients who had never attempted suicide for suicide risk factors. RESULTS: Among the 149 HIV positive patients examined almost half had attempted suicide. Significantly more HIV positive patients who had attempted suicide were female. Attempters were significantly younger than non-attempters. Significantly more of the attempters had a family history of suicidal behaviour. Attempters also reported significantly more childhood trauma, scored significantly higher for neuroticism, had experienced significantly more comorbidity with depression, and more of them had received antidepressant medication. CONCLUSION: These data suggest that both distal and proximal risk factors are involved in suicidal behaviour in HIV positive substance dependent patients.     

Relationship of birth cohort and early age at onset of illness in a bipolar disorder case registry

OBJECTIVE: Utilizing data from a previously characterized registry of subjects with bipolar illness, the authors examined age at onset of the first illness episode in cohorts of subjects born from 1900 through 1939 and from 1940 through 1959. METHOD: Demographic and clinical characteristics at the first full episode of bipolar disorder of subjects in a diagnostically validated voluntary bipolar disorder registry (N=1,218) were reviewed and subjected to statistical analyses. RESULTS: The median age at onset of the first episode of bipolar illness was lower by 4.5 years in subjects born during or after 1940 (median age=19 years), compared with subjects born before 1940 (median age=23.5 years). The proportion of subjects with bipolar disorder presenting with a prepubertal onset was significantly higher in the later birth-year cohort than in the earlier birth-year cohort. More than 50% of male and female subjects in both cohorts had a depressive episode as the first episode of bipolar illness. Subjects in each cohort who had a parent with major depression, bipolar disorder, or schizophrenia experienced their first episode nearly 4 to 5 years earlier than the other subjects in the cohort. CONCLUSIONS: Prospective epidemiological studies conducted with bipolar disorder subjects are needed to either affirm or refute these data on age at illness onset. If the results are affirmed, the early recognition of prepubertal bipolar disorder will be important, so that the condition can be treated with appropriate medications and medications that could potentially worsen the illness course can be avoided. Similarly, early recognition of bipolar illness is important, especially in women, to minimize use of antidepressant monotherapy for patients with bipolar illness. Among young people presenting with major depression as the first illness episode, a parental history of major depression, bipolar disorder, or psychosis may be a useful pointer to future bipolar disorder. Early recognition and appropriate treatment of bipolar illness may prevent the development of chronicity and serious functional impairment.     

Voluntary exercise increases neurotrophin-3 and its receptor TrkC in the spinal cord

We have evaluated changes in the expression of neurotrophin-3 (NT-3) and its tyrosine kinase C (TrkC) receptor in the neuromuscular system as a result of voluntary physical activity. We assessed changes in the mRNAs and proteins for NT-3 and TrkC in the lumbar spinal cord and associated soleus muscle following 3 and 7 days of voluntary wheel running. We used quantitative Taqman RT-PCR to measure mRNA and ELISA to assess protein levels. NT-3 mRNA and protein levels increased in the spinal cord to reach statistical significance after 7 days of exercise compared to sedentary control rats. Immunohistochemical analyses localized the elevated NT-3 to the substantia gelatinosa (SG) and nucleus of the dorsal horn. TrkC mRNA levels were significantly elevated in the spinal cord after 3 and 7 days of running. In the soleus muscle, NT-3 mRNA levels and its receptor TrkC were elevated after 3 days, while NT-3 protein levels remained unaffected. The results demonstrate that voluntary exercise has a differential effect on NT-3 as well as its receptor TrkC in the neural and muscular components of the neuromuscular system, and emphasize the role of voluntary activity on the spinal cord and muscle.     

Peripheral nerve ischemia: apolipoprotein E deficiency results in impaired functional recovery and reduction of associated intraneural angiogenic response

Apolipoprotein E-knockout (apoE KO) mice have peripheral sensory nerve defects, reduced and delayed response to noxious thermal stimuli, abnormal morphology of unmyelinated fibers, and impaired blood-nerve and blood-brain barriers. In this study, we show that, compared to wild-type mice, peripheral nerves of apoE KO mice have impaired ability to respond to ischemia, as demonstrated by measurement of motor and sensory conduction velocity. In addition, mice lacking apoE exhibit a deficit of reinnervation of ischemic epidermis, evaluated by immunofluorescent staining for the pan-neuronal marker PGP 9.5. Also regional nerve blood flow, measured by laser Doppler, and intraneural angiogenesis after ischemia are significantly compromised in apoE-deficient mice. Finally, upregulation of the angiogenic cytokine vascular endothelial growth factor (VEGF), which physiologically occurs after ischemia in the peripheral nerve of wild-type mice, is severely impaired in apoE KO mice. Among the several neural defects that have already been described in mice lacking apoE, this is the first demonstration that functional recovery to ischemia is impaired in the peripheral nerves of these animals. This deficit is mirrored by the inability of upregulating VEGF and mounting an appropriate intraneural angiogenic response following injury. These findings provide new evidence of possible interdependent relationships between VEGF, angiogenesis, and nerve function and regeneration and may provide new important information on the role of apoE in the nervous system.     

Directed nerve outgrowth is enhanced by engineered glial substrates

In the present study, the influence of astrocyte alignment on the direction and length of regenerating neurites was examined in vitro. Astrocytes were experimentally manipulated by different approaches to create longitudinally aligned monolayers. When cultured on the aligned monolayers, dorsal root ganglion neurites grew parallel to the long axis of the aligned astrocytes and were significantly longer than controls. Engineered monolayers expressed linear arrays of fibronectin, laminin, neural cell adhesion molecule, and chondroitin sulfate proteoglycan that were organized parallel to one another, suggesting that a particular spatial arrangement of these molecules on the astrocyte surface may be necessary to direct nerve regeneration in vivo. In contrast, no bias in directional outgrowth was observed for neurites growing on unorganized monolayers. The results suggest that altering the organization of astrocytes and their scar-associated matrix at the lesion site may be used to influence the direction and the length of adjacent regenerating axons in the damaged brain and spinal cord.     

Post-cardiorespiratory arrest beta-alpha coma: an unusual electroencephalographic phenomenon

The presence of frontally-dominant alpha pattern in the EEG is common in patients with coma due to trauma, toxic-metabolic causes and following cardiorespiratory arrest. Diffuse beta activity following resuscitation after a cardiac arrest is not well recognized. We report a case of coma in a 3-year-old girl who had a cardiac arrest from which she was revived. Initial EEG showed diffuse beta activity, which later evolved to predominantly alpha activity. The possible mechanisms involved in the generation of such rhythms are discussed. Transition of EEG activity from faster to slower frequencies is suggested as an adverse prognostic factor in post-cardiorespiratory arrest coma.