Alcohol-induced hangover, defined by a series of symptoms, is the most commonly reported consequence of excessive alcohol consumption. Alcohol hangovers contribute to workplace absenteeism, impaired job performance, reduced productivity, poor academic achievement, and may compromise potentially dangerous daily activities such as driving a car or operating heavy machinery. These socioeconomic consequences and health risks of alcohol hangover are much higher when compared to various common diseases and other health risk factors. Nevertheless, unlike alcohol intoxication the hangover has received very little scientific attention and studies have often yielded inconclusive results. Systematic research is important to increase our knowledge on alcohol hangover and its consequences. This consensus paper of the Alcohol Hangover Research Group discusses methodological issues that should be taken into account when performing future alcohol hangover research. Future research should aim to (1) further determine the pathology of alcohol hangover, (2) examine the role of genetics, (3) determine the economic costs of alcohol hangover, (4) examine sex and age differences, (5) develop common research tools and methodologies to study hangover effects, (6) focus on factor that aggravate hangover severity (e.g., congeners), and (7) develop effective hangover remedies.

In this study, possible mechanisms underlying soleus muscle atrophy after spinal cord transection and attenuation of atrophy with cycling exercise were studied. Adult female Sprague-Dawley rats were divided into three groups; in two groups the spinal cord was transected by a lesion at T10. One group was transected and killed 10 days later, and another group was transected and exercised for 5 days starting 5 days after transection. The third group served as an uninjured control. All animals received a continuous-release 5′-bromo-2′-deoxyuridine pellet 10 days before they were killed. Transection alone and transection with exercise lead to activation of satellite cells, but only the exercise group showed a trend toward an increase in the number of proliferating satellite cells. In all cases the number of activated satellite cells was significantly higher than the number that divided. Although the number of cells undergoing proliferation increased with exercise, no increase in fusion of satellite cells into muscle fibers was apparent. Spinal cord transection resulted in a 25% decrease in myonuclear number, and exercise was not associated with a restoration of myonuclear number. The number of apoptotic nuclei was increased after transection, and exercise attenuated this increase. However, the decrease in apoptotic nuclei with exercise did not significantly affect myonuclear number. We conclude that apoptotic nuclear loss likely contributes to loss of nuclei during muscle atrophy associated with spinal cord transection and that exercise can maintain muscle mass, at least in the short term, without restoration of myonuclear number.

We have shown that cycling exercise combined with fetal spinal cord transplantation restored muscle mass reduced as a result of complete transection of the spinal cord. In this study, mechanisms whereby this combined intervention increased the size of atrophied soleus and plantaris muscles were investigated. Rats were divided into five groups (n = 4, per group): control, nontransected; spinal cord transected at T10 for 8 wk (Tx); spinal cord transected for 8 wk and exercised for the last 4 wk (TxEx); spinal cord transected for 8 wk with transplantation of fetal spinal cord tissue into the lesion site 4 wk prior to death (TxTp); and spinal cord transected for 8 wk, exercised for the last 4 wk combined with transplantation 4 wk prior to death (TxExTp). Tx soleus and plantaris muscles were decreased in size compared with control. Exercise and transplantation alone did not restore muscle size in soleus, but exercise alone minimized atrophy in plantaris. However, the combination of exercise and transplantation resulted in a significant increase in muscle size in soleus and plantaris compared with transection alone. Furthermore, myofiber nuclear number of soleus was decreased by 40% in Tx and was not affected in TxEx or TxTp but was restored in TxExTp. A strong correlation (r = 0.85) between myofiber cross-sectional area and myofiber nuclear number was observed in soleus, but not in plantaris muscle, in which myonuclear number did not change with any of the experimental manipulations. 5'-Bromo-2'-deoxyuridine-positive nuclei inside the myofiber membrane were observed in TxExTp soleus muscles, indicating that satellite cells had divided and subsequently fused into myofibers, contributing to the increase in myonuclear number. The increase in satellite cell activity did not appear to be controlled by the insulin-like growth factors (IGF), as IGF-I and IGF-II mRNA abundance was decreased in Tx soleus and plantaris, and was not restored with the interventions. These results indicate that, following a relatively long postinjury interval, exercise and transplantation combined restore muscle size. Satellite cell fusion and restoration of myofiber nuclear number contributed to increased muscle size in the soleus, but not in plantaris, suggesting that cellular mechanisms regulating muscle size differ between muscles with different fiber type composition.

We examined the influence of 1) prior increase [preheating (PHT)], 2) increase throughout [heating (HT)], and 3) no increase [control (Con)] of body heat content (H(b)) on neuromuscular function and manual dexterity of the hands during a 130-min exposure to -20 degrees C (coldEx). Ten volunteers randomly underwent three passive coldEx, incorporating a 10-min moderate-exercise period at the 65th min while wearing a liquid conditioning garment (LCG) and military arctic clothing. In PHT, 50 degrees C water was circulated in the LCG before coldEx until core temperature was increased by 0.5 degrees C. In HT, participants regulated the inlet LCG water temperature throughout coldEx to subjective comfort, while the LCG was not operating in Con. Thermal comfort, rectal temperature, mean skin temperature, mean finger temperature (T(fing)), change in H(b) (DeltaH(b)), rate of body heat storage, Purdue pegboard test, finger tapping, handgrip, maximum voluntary contraction, and evoked twitch force of the first dorsal interosseus muscle were recorded. Results demonstrated that, unlike in HT and PHT, thermal comfort, rectal temperature, mean skin temperature, twitch force, maximum voluntary contraction, and finger tapping declined significantly in Con. In contrast, T(fing) and Purdue pegboard test remained constant only in HT. Generalized estimating equations demonstrated that DeltaH(b) and T(fing) were associated over time with hand function, whereas no significant association was detected for rate of body heat storage. It is concluded that increasing H(b) not only throughout but also before a coldEx is effective in maintaining hand function. In addition, we found that the best indicator of hand function is DeltaH(b) followed by T(fing).