338 research outputs found

    Distinguishing Increased Adiposity and/or Aerobic Deconditioning as Moderators of Low VO2peak in Obese Men

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    Peak oxygen uptake (V̇O2peak) in a cardiopulmonary exercise test (CPET) is a strong predictor of morbidity, mortality, and quality of life. V̇O2peak in obese individuals is typically below the lower limit of normal (2 transport and utilization, i.e. aerobic deconditioning; or both. We hypothesized a modified CPET, to measure the fraction of maximum isokinetic power that can be supported by aerobic metabolism, will distinguish between adiposity and deconditioning effects on V̇O2peak. PURPOSE: To compare V̇O2peak and isokinetic neuromuscular performance in obese vs non-obese men. METHODS: A modified CPET with maximal (3 s) isokinetic cycling power at baseline and the limit of ramp-incremental (RI) exercise was used to calculate: A) baseline maximum isokinetic power (Piso); B) tolerance index (TI), % of Piso at V̇O2peak; C) fatigue index (FI), % reduction in Piso per RI-watt at V̇O2peak; D) power reserve (PR), isokinetic power available at V̇O2peak expressed as % RI-wattpeak. The FRIEND nomogram was used to predict V̇O2peak. Data are mean(SD) and were assessed by t-test. RESULTS: Compared to controls (n=24), obese men (n=20) were older (32(5) vs 26(7) yr), had greater BMI (38(6) vs 23(2) kg/m2), but were not different in stature (177(5) vs 180(7) cm) or predicted V̇O2peak (3.49(0.49) vs 3.58(0.36) L/min). Obese men had lower V̇O2peak (2.84(0.42) vs 3.71(0.45) L/min, p2peak (82(15) vs 104(12) %, pIndependent of body mass, obese men had preserved leg strength (normal Piso), but the fraction of maximum isokinetic power supported by aerobic metabolism at RI intolerance was reduced (low TI) with greater fatigability (high FI); each consistent with aerobic deconditioning. A modified CPET with maximal isokinetic power measurements can distinguish the effects of increased adiposity from aerobic deconditioning on V̇O2peak in obese men

    Testosterone Administration Decreases Generosity in the Ultimatum Game

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    How do human beings decide when to be selfish or selfless? In this study, we gave testosterone to 25 men to establish its impact on prosocial behaviors in a double-blind within-subjects design. We also confirmed participants' testosterone levels before and after treatment through blood draws. Using the Ultimatum Game from behavioral economics, we find that men with artificially raised T, compared to themselves on placebo, were 27% less generous towards strangers with money they controlled (95% CI placebo: (1.70, 2.72); 95% CI T: (.98, 2.30)). This effect scales with a man's level of total-, free-, and dihydro-testosterone (DHT). Men in the lowest decile of DHT were 560% more generous than men in the highest decile of DHT. We also found that men with elevated testosterone were more likely to use their own money punish those who were ungenerous toward them. Our results continue to hold after controlling for altruism. We conclude that elevated testosterone causes men to behave antisocially

    Six weeks of conditioning exercise increases total, but not free testosterone in lifelong sedentary aging men

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    Introduction: Advancing age is associated with a gradual decline in circulating androgens, and the putative role of exercise training on systemic androgens remains to be adequately defined. Methods: The present investigation examined the impact of 6 weeks of supervised exercise training on resting levels of systemic hormones in a cohort of lifelong sedentary men [SED (n = 28), 62.5 ± 5.3 years], compared with a positive control group of age-matched lifelong exercisers [LE (n = 20), 60.4 ± 4.7 years, >30 years training history]. Blood hormones were sampled pre- and post-intervention from an antecubital forearm vein and analysed using electrochemiluminescent immunoassay. Cardiorespiratory fitness () was determined via indirect calorimetry during an incremental cycle test to volitional exhaustion. Results: Analysis of variance (ANOVA) revealed a lack of significant change in any parameter amongst LE, whilst SED experienced a significant exercise-induced improvement in cardiorespiratory fitness and total testosterone (all p  0.05) amongst SED. Conclusions: Although resting levels of systemic total testosterone increased in response to 6 weeks of exercise training, increases in SHBG negated any potential relationship between calculated-free or bioavailable testosterone. These findings indicate that increases in bioavailable testosterone fraction are not required for cardiorespiratory fitness improvements in aging men

    A Right Atrial Hemangioma Mimicking Thrombus In A Patient With Atrial Arrhythmias

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    Cardiac hemangiomas are rare tumors, accounting for only 2.8% of all benign primary cardiac tumors and occur at any age. Clinical presentations vary depending on the tumor location (myocardial, endocardial or pericardial). In many cases, this may be an incidental finding. We report the case of a patient with paroxysmal atrial fibrillation who had a right atrial hemangioma detected with transesophageal echocardiography prior to having percutaneous pulmonary vein isolation performe

    Construction statistics review for Kenya

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    Construction is a strategic industry in the developing economies like Kenya. In order for construction to ably perform this role, there is need to provide information on its various economic aspects including raw materials, products, processes, finance, and labour. Construction statistics of Kenya have been evaluated in order to ascertain their adequacy in terms of scope, portrait, reliability and responsiveness in their coverage of the construction industry. Official statistics published in the annual Statistical Abstract were reviewed according to these adequacy criteria. The findings are that: the scope of construction statistics is narrowly defined making the statistical portrait of the sector to be incomplete; the statistics are also unreliable in terms of quality and unresponsive to economical challenges of inflation, structural adjustment policies and the decline of public sector's role in the construction industry. A participatory statistical governance framework is recommended in order to improve the scope of statistics and alleviate the attendant problems like incomplete portrait that come with the narrow scope

    Methylation at Global LINE-1 Repeats in Human Blood Are Affected by Gender but Not by Age or Natural Hormone Cycles

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    Previously, we reported on inter-individual and gender specific variations of LINE-1 methylation in healthy individuals. In this study, we investigated whether this variability could be influenced by age or sex hormones in humans. To this end, we studied LINE-1 methylation in vivo in blood-derived DNA from individuals aged 18 to 64 years and from young healthy females at various hormone levels during the menstrual cycle. Our results show that no significant association with age was observed. However, the previously reported increase of LINE-1 methylation in males was reconfirmed. In females, although no correlation between LINE-1 or Alu methylation and hormone levels was observed, a significant stable individual specific level of methylation was noted. In vitro results largely confirmed these findings, as neither estrogen nor dihydrotestosterone affected LINE-1 or Alu methylation in Hek293T, HUVEC, or MDA-kb2 cell lines. In contrast, a decrease in methylation was observed in estrogen-treated T47-Kbluc cell lines strongly expressing estrogen receptor. The very low expression of estrogen receptor in blood cells could explain the observed insensitivity of methylation at LINE-1 to natural hormonal variations in females. In conclusion, neither natural cycle of hormones nor age has a detectable effect on the LINE-1 methylation in peripheral blood cells, while gender remains an important factor
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