AJA publishes new findings in basic and clinical (including modern, traditional and epidemiological) research on Andrology.

The study investigated the effect of prolonged hypoxia on central [i.e., cardiovascular oxygen delivery (Q̇_aO₂)] and peripheral (i.e., O₂ utilization) determinants of oxidative metabolism response during exercise in humans. To this aim, seven male mountaineers were examined before and immediately after the Himalayan Expedition Interamnia 8000–Manaslu 2008, lasting 43 days, among which, 23 days were above 5,000 m. The subjects showed a decrease in body weight ( P < 0.05) and of power output during a Wingate Anaerobic test ( P < 0.05) and an increase of thigh cross-sectional area ( P < 0.05). Absolute maximal O₂ uptake (V̇O_2max) did not change. The mean response time of V̇O₂ kinetics at the onset of step submaximal cycling exercise was reduced significantly from 53.8 s ± 10.9 to 39.8 s ± 10.9 ( P < 0.05), whereas that of Q̇_aO₂ was not. Analysis of single fibers dissected from vastus lateralis biopsies revealed that the expression of slow isoforms of both heavy and light myosin subunits increased, whereas that of fast isoforms decreased. Unloaded shortening velocity of fibers was decreased significantly. In summary, independent findings converge in indicating that adaptation to chronic hypoxia brings about a fast-to-slow transition of muscle fibers, resulting in a faster activation of the mitochondrial oxidative metabolism. These results indicate that a prolonged and active sojourn in hypoxia may induce muscular ultrastructural and functional changes similar to those observed after aerobic training.

Human exposure to altitude is a model to study the role of oxygen in different areas of physiology and pathophysiology. The aim of this study was to evaluate whether a short exposure to hypoxia (5 days) combined with exercise, at altitude ranging from 900 m above sea level to 5895 m above sea level (Kilimanjaro Expedition) can modify seminal and reproductive hormonal parameter levels in human beings. During the ascent, blood oxygen saturation at 3.848 m above sea level was found to be decreased when compared to sea level (P < 0.02). The sperm forward motility at sea level after the expedition showed a significant reduction ​​(P < 0.02). There were no changes in other seminal parameters among those compared. Determination of the hormonal plasma concentrations showed that baseline values of follicle-stimulating hormone, total testosterone, prolactin and oestradiol were unchanged at sea level after the hypoxic experience, with respect to baseline values at sea level. On the other hand, luteinising hormone levels after altitudes trekking significantly increased compared to levels before the expedition (P < 0.05). Because of the short-term exposure, we can assume that the reduced forward motility described here may result from the effects of the acute altitude hypoxia on spermatozoa during the epididymal transit where they mature acquiring their motility.

Difficulties in handwriting are often reported in children with developmental coordination disorder (DCD), and they represent an important element in the diagnosis. The present study was aimed at investigating the relation between motor coordination and handwriting skills, and to identify differences in handwriting between children without and with coordination difficulties. In particular, we asked whether visual-spatial skills have a role as mediating variables between motor coordination and handwriting. We assessed motor coordination as well as graphic abilities in children aged 7-10 years. Moreover, we evaluated their visual-motor integration, visual-spatial skills, and other cognitive abilities (memory and planning). We found no relation between motor coordination and handwriting skills, while visual-spatial skills (measured by a visual-constructive task) were related with both. Our conclusion is that visual-spatial skills are involved both in general motor coordination and in handwriting, but the relationship involves different aspects in the two cases.