Oral Coenzyme Q10 supplementation does not prevent cardiac alterations during a high altitude trek to everest base cAMP.

Exposure to high altitude is associated with sustained, but reversible, changes in cardiac mass, diastolic function, and high-energy phosphate metabolism. Whilst the underlying mechanisms remain elusive, tissue hypoxia increases generation of reactive oxygen species (ROS), which can stabilize hypoxia-inducible factor (HIF) transcription factors, bringing about transcriptional changes that suppress oxidative phosphorylation and activate autophagy. We therefore investigated whether oral supplementation with an antioxidant, Coenzyme Q10, prevented the cardiac perturbations associated with altitude exposure. Twenty-three volunteers (10 male, 13 female, 46±3 years) were recruited from the 2009 Caudwell Xtreme Everest Research Treks and studied before, and within 48 h of return from, a 17-day trek to Everest Base Camp, with subjects receiving either no intervention (controls) or 300 mg Coenzyme Q10 per day throughout altitude exposure. Cardiac magnetic resonance imaging and echocardiography were used to assess cardiac morphology and function. Following altitude exposure, body mass fell by 3 kg in all subjects (p<0.001), associated with a loss of body fat and a fall in BMI. Post-trek, left ventricular mass had decreased by 11% in controls (p<0.05) and by 16% in Coenzyme Q10-treated subjects (p<0.001), whereas mitral inflow E/A had decreased by 18% in controls (p<0.05) and by 21% in Coenzyme Q10-treated subjects (p<0.05). Coenzyme Q10 supplementation did not, therefore, prevent the loss of left ventricular mass or change in diastolic function that occurred following a trek to Everest Base Camp.

I-131 MIBG post-therapy scan is more sensitive than I-123 MIBG pretherapy scan in the evaluation of metastatic neuroblastoma.

OBJECTIVE: Iodine-123 metaiodobenzylguanidine (I-123 MIBG) scintigraphy is gradually replacing I-131 MIBG scans in the diagnostic workup of neuroblastoma. High-dose I-131 MIBG, however, is commonly used for subsequent therapy in patients with proven MIBG-avid lesions. The objective of this study was to compare the sensitivities of pretherapy I-123 MIBG and post-therapy I-131 MIBG scans for detecting metastatic lesions of neuroblastoma and determine the suitability of post-therapy scans for detecting new metastases. MATERIALS AND METHODS: Pretherapy I-123 MIBG scans and post-therapy I-131 MIBG scans of 126 patients with neuroblastoma were analyzed retrospectively and the number of detected lesions was compared. RESULTS: In 70 patients (55.6% cases), the pretherapy and post-therapy scans were concordant, showing similar MIBG-avid foci. In the remaining 56 patients (44.4% cases), the post-therapy I-131 MIBG scans revealed additional lesions (i.e. a total of 716 lesions) compared with pretherapy I-123 MIBG scans (only 532 lesions). All lesions detected on pretherapy I-123 MIBG scans were revisualized on the post-therapy I-131 MIBG scans, the latter also revealing 184 new MIBG-avid lesions. CONCLUSION: Post-therapy I-131 MIBG scans demonstrate new lesions in almost half of the patients when compared with pretherapy I-123 MIBG scans and therefore are essential to delineate the disease extent.

Short-term consumption of a high-fat diet impairs whole-body efficiency and cognitive function in sedentary men.

We recently showed that a short-term high-fat diet blunted exercise performance in rats, accompanied by increased uncoupling protein levels and greater respiratory uncoupling. In this study, we investigated the effects of a similar diet on physical and cognitive performance in humans. Twenty sedentary men were assessed when consuming a standardized, nutritionally balanced diet (control) and after 7 d of consuming a diet comprising 74% kcal from fat. Efficiency was measured during a standardized exercise task, and cognition was assessed using a computerized assessment battery. Skeletal muscle mitochondrial function was measured using (31)P magnetic resonance spectroscopy. The diet increased mean ± se plasma free fatty acids by 44% (0.32±0.03 vs. 0.46±0.05 mM; P<0.05) and decreased whole-body efficiency by 3% (21±1 vs. 18±1%; P<0.05), although muscle uncoupling protein (UCP3) content and maximal mitochondrial function were unchanged. High-fat diet consumption also increased subjects' simple reaction times (P<0.01) and decreased power of attention (P<0.01). Thus, we have shown that a high-fat diet blunts whole-body efficiency and cognition in sedentary men. We suggest that this effect may be due to increased respiratory uncoupling.