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In medial tibial stress syndrome (MTSS) bone marrow and periosteal edema of the tibia on the magnetic resonance imaging (MRI) is frequently reported. The relationship between these MRI findings and recovery has not been previously studied. This prospective study describes MRI findings of 52 athletes with MTSS. Baseline characteristics were recorded and recovery was related to these parameters and MRI findings to examine for prognostic factors. Results showed that 43.5% of the symptomatic legs showed bone marrow or periosteal edema. Absence of periosteal and bone marrow edema on MRI was associated with longer recovery (P = 0.033 and P = 0.013). A clinical scoring system for sports activity (SARS score) was significantly higher in the presence of bone marrow edema (P = 0.027). When clinical scoring systems (SARS score and the Lower Extremity Functional Scale) were combined in a model, time to recovery could be predicted substantially (explaining 54% of variance, P = 0.006). In conclusion, in athletes with MTSS, bone marrow or periosteal edema is seen on MRI in 43,5% of the symptomatic legs. Furthermore, periosteal and bone marrow edema on MRI and clinical scoring systems are prognostic factors. Future studies should focus on MRI findings in symptomatic MTSS and compare these with a matched control group.

CRF is recognised for its actions on pituitary ACTH release, but also has direct effects within the brain which are important in mediating physiological responses to stress. Behavioral effects of CRF include increased locomotor activity and inhibition of food intake and its actions on metabolism are mediated mainly by activation of the sympathetic nervous system. CRF appears to be important in the regulation of energy balance and body weight, influencing both food intake and sympathetically-mediated thermogenesis. A defect in the synthesis or release of CRF has been implicated in the development of obesity in laboratory animals, since the condition is alleviated by adrenalectomy, hypophysectomy or exogenous CRF treatment. Recent data have revealed an additional role for CRF as a mediator of the neuroendocrine and metabolic responses to immune signals, particularly cytokines. The central actions of CRF are independent of the pituitary but may involve release of proopiomelanocortin products within the brain. CRF is thus emerging as an important integrator of the physiological responses to stress, infection and immunity, a finding which may have important implications for future therapies.

AbstractAlcohol (ethanol) use is almost normative by late adolescence, in most western countries. It is important to identify factors that distinguish those who progress from alcohol initiation to sustained use of the drug, from those that keep a controlled pattern of drinking. The factors precipitating this transition may change across development. This study analyzed associations between behavioral endophenotypes and ethanol intake at three developmental periods. Exp. 1 measured ethanol drinking at postnatal day 18, via an intraoral infusion procedure, in male or female pre‐weanling rats screened for anxiety response in the light‐dark box test and for distance traveled in a novel open field. Exp. 2 measured, in juvenile/adolescent or young adult rats, the association between shelter seeking, exploratory/risk‐taking behaviors, anxiety or hedonic responses, and ethanol intake. Ethanol intake in pre‐weanlings was explained by distance traveled in a novel environment, whereas anxiety responses, measured in the multivariate concentric square field apparatus (MSCF), selectively predicted ethanol intake at adolescence, but not at adulthood. Those juvenile/adolescents with lower mean duration of visit to areas of the MSCF that evoke anxiogenic responses exhibited heightened ethanol intake. These findings suggest that the association between anxiety and ethanol intake may be specifically relevant during adolescence.

Quantitative aspects of the potentiation of GABA and muscimol by benzodiazepines and barbiturates are reviewed, taking account of both electrophysiological and receptor binding data. It has been a consistent finding that barbiturates cause a greater maximal potentiation than do benzodiazepines. The steroid anaesthetic alphaxalone and some naturally occurring steroids were compared as potentiators of electrophysiological responses to muscimol. From the relative potencies, important structural features of the steroid molecule for this effect have been identified. The possibility of the barbiturates and the steroids having a common mode of action as potentiators of GABA and muscimol is discussed, together with the idea that this action may involve perturbation of membrane lipids rather than a barbiturate/steroid receptor site. The GABA-potentiating effect of ethanol may also be barbiturate-like but potentiations by chlormethiazole and ketamine appear to involve different mechanisms. It is predicted that any endogenous potentiators of GABA would be unlikely to have more than a modest effect.

This study investigated the effects of alcohol septal ablation (ASA) on microcirculatory function and myocardial energetics in patients with hypertrophic cardiomyopathy (HCM) and left ventricular outflow tract (LVOT) obstruction. In 15 HCM patients who underwent ASA, echocardiography was performed before and 6 mo after the procedure to assess the LVOT gradient (LVOTG). Additionally, [15O]water PET was performed to obtain resting myocardial blood flow (MBF) and coronary vasodilator reserve (CVR). Changes in LV mass (LVM) and volumes were assessed by cardiovascular magnetic resonance imaging. Myocardial oxygen consumption (MV̇o2) was evaluated by [11C]acetate PET in a subset of seven patients to calculate myocardial external efficiency (MEE). After ASA, peak LVOTG decreased from 41 ± 32 to 23 ± 19 mmHg ( P = 0.04), as well as LVM (215 ± 74 to 169 ± 63 g; P < 0.001). MBF remained unchanged (0.94 ± 0.23 to 0.98 ± 0.15 ml·min−1·g−1; P = 0.45), whereas CVR increased (2.55 ± 1.23 to 3.05 ± 1.24; P = 0.05). Preoperatively, the endo-to-epicardial MBF ratio was lower during hyperemia compared with rest (0.80 ± 0.18 vs. 1.18 ± 0.15; P < 0.001). After ASA, the endo-to-epicardial hyperemic (h)MBF ratio increased to 1.03 ± 0.26 ( P = 0.02). ΔCVR was correlated to ΔLVOTG ( r = −0.82; P < 0.001) and ΔLVM ( r = −0.54; P = 0.04). MEE increased from 15 ± 6 to 20 ± 9% ( P = 0.04). Coronary microvascular dysfunction in obstructive HCM is at least in part reversible by relief of LVOT obstruction. After ASA, hMBF and CVR increased predominantly in the subendocardium. The improvement in CVR was closely correlated to the absolute reduction in peak LVOTG, suggesting a pronounced effect of LV loading conditions on microvascular function of the subendocardium. Furthermore, ASA has favorable effects on myocardial energetics.

Practice may modify the effects of alcohol on perceptual-motor performance in at least three different ways: (1) alcohol may affect learning—that is, the rate at which performance of a skill improves with practice; (2) alcohol may have a greater effect on performance when the skill is unfamiliar than when it is practised; and (3) practice with alcohol may allow adaptation to its effects. These were investigated using a simple computer game in which subjects attempted to destroy a tank by pressing a key to release a bomb from a plane horizontally traversing the screen above it. The results demonstrated that (1) performance improved with practice; (2) with alcohol (0.8 mg/kg body weight), subjects were more variable and less accurate; (3) improvement with alcohol was greater than without alcohol, but as performance was impaired by alcohol, there was greater scope for improvement; (4) those who practised with alcohol still improved when switched to no alcohol late in practice; and (5) alcohol had the same effect early and late in practice. It is therefore concluded that there is no evidence to support any of the three suggestions outlined above.

Adolescents may be more sensitive to stress-induced alcohol drinking than adults, which would explain the higher prevalence of alcohol abuse and dependence in late adolescence than in adulthood. The present study analyzed the impact of restraint stress on the initiation of alcohol intake across 2 weeks of intermittent, two-bottle choice intake in male and female adolescent rats and adult female rats. Restraint stress significantly increased alcohol intake and preference in female adolescent rats but decreased alcohol intake and preference in male adolescent and female adult rats. The effects of restraint stress on alcohol intake were mitigated in adolescent females following administration of the κ opioid receptor antagonist norbinaltorphimine. Adolescent but not adult female rats that were subjected to restraint stress spent more time on the open arms of the elevated plus maze. Female adolescents exposed to stress also exhibited greater risk-taking behaviors in a concentric square field test compared with non-stressed controls. These results indicate age- and sex-related differences in the sensitivity to alcohol-stress interactions that may facilitate the initiation of alcohol use in female adolescents. The facilitatory effect of stress on alcohol intake was related to greater exploratory and risk-taking behaviors in young females after stress exposure.