Little or no ability of obestatin to interact with ghrelin or modify motility in the rat gastrointestinal tract.

BACKGROUND AND PURPOSE: Obestatin, encoded by the ghrelin gene may inhibit gastrointestinal (GI) motility. This activity was re-investigated. EXPERIMENTAL APPROACH: Rat GI motility was studied in vitro (jejunum contractility and cholinergically-mediated contractions of forestomach evoked by electrical field stimulation; EFS) and in vivo (gastric emptying and intestinal myoelectrical activity). Ghrelin receptor function was studied using a GTPgammaS assay and transfected cells. KEY RESULTS: Contractions of the jejunum or forestomach were unaffected by obestatin 100 nM or 0.01-1000 nM, respectively (P>0.05 each; n=4-18). Obestatin (0.1-1 nM) reduced the ability of ghrelin 1 microM to facilitate EFS-evoked contractions of the stomach (increases were 42.7+/-7.8% and 21.2+/-5.0 % in the absence and presence of obestatin 1 nM; P<0.05; n=12); higher concentrations (10-1000 nM) tended to reduce the response to ghrelin but changes were not statistically significant. Similar concentrations of obestatin did not significantly reduce a facilitation of contractions caused by the 5-HT(4) receptor agonist prucalopride, although an inhibitory trend occurred at the higher concentrations (increases were 69.3+/-14.0% and 42.6+/-8.7% in the absence and presence of 1000 nM obestatin; n=10). Obestatin (up to 10 microM) did not modulate recombinant ghrelin receptor function. Ghrelin increased gastric emptying and reduced MMC cycle time; obestatin (1000 and 30,000 pmol kg(-1) min(-1)) had no effects. Obestatin (2500 pmol kg(-1) min(-1), starting 10 min before ghrelin) did not prevent the ability of ghrelin (500 pmol kg(-1) min(-1)) to shorten MMC cycle time. CONCLUSIONS AND IMPLICATIONS: Obestatin has little ability to modulate rat GI motility.

Does amateur boxing lead to chronic brain damage? A review of some recent investigations.

Fifty former amateur boxers were examined and compared with two control groups of soccer players and track and field athletes. All subjects were interviewed regarding their sports career, medical history, and social variables. They underwent a physical and a neurologic examination. Personality traits were investigated and related to the platelet monoamine oxidase activity. Cerebral morphologic changes were evaluated using computed tomography and magnetic resonance imaging. Further, clinical neurophysiologic tests were made as well as neuropsychologic tests. No significant differences were found between the groups in any of the physical or neurologic examinations or in platelet monoamine oxidase activity. Socially, the boxers had a lower degree of education and had chosen less intellectual professions, but they were less impulsive and more socialized. The computed tomography images and magnetic resonance imaging studies showed no significant differences between the groups. There was a significantly higher incidence of slight or moderate electroencephalography deviations among the boxers. Neuropsychologically, the boxers had an inferior finger-tapping performance. Thus, no signs of serious chronic brain damage were found among any of the groups studied. However, the electroencephalography and finger-tapping differences between the groups might indicate slight brain dysfunction in some of the amateur boxers.

Does Swedish amateur boxing lead to chronic brain damage? 2. A retrospective study with CT and MRI.

It is well known that professional boxers can develop chronic traumatic encephalopathy (dementia pugilistica) due to repeated head trauma. Beside CT findings indicating cerebral atrophy, the presence of a cavum septum pellucidum has been reported to indicate encephalopathy. CT findings in amateur boxers are not as well documented. The aim of this study was to find out if morphological changes could be demonstrated among former amateur boxers using CT and MRI. Two control groups of soccer players and track and field athletes in the same age-range were used for comparison. No significant differences in the width of the ventricular system, anterior horn index, width of cortical sulci, signs of vermian atrophy, or the occurrence of a cavum septum pellucidum were found between boxers and controls. A cavum septum pellucidum was found more often in the controls than in the boxers and is probably not a sign of earlier head trauma. MRI confirm no more findings than CT in this retrospective study.

Does Swedish amateur boxing lead to chronic brain damage? 4. A retrospective neuropsychological study.

Does Swedish amateur boxing lead to any permanent neuropsychological deficit, caused by chronic brain damage? Fifty Swedish former amateur boxers, 25 soccer players, and 25 track and field athletes were investigated by standardized neuropsychological tests. In only one test did the groups differ significantly. Boxers who had taken part in a large number of bouts had a slightly inferior finger-tapping performance. None of the boxers were considered to have definite signs of intellectual impairment. In conclusion modern Swedish amateur boxing does not seem to lead to significant signs of neuropsychological impairment or "punch drunkenness", nor does it seem to differ in this respect from soccer playing or track and field sports.

Prospective study of concentric and eccentric leg muscle torques, flexibility, physical conditioning, and variation of injury rates during one season of amateur ice hockey.

Twenty-three male ice hockey players in a third division amateur ice hockey team were prospectively studied during the 1987-1988 season. O2 uptake, muscle flexibility, and isokinetic concentric and eccentric leg muscle strength were measured before and after the season. All injuries were recorded by one and the same physician attending all the games: 68 injuries occurred altogether but only six of these led to absence from training or matches. O2 uptake and muscle flexibility were unchanged during the season, but a significant drop of both concentric and eccentric quadriceps and hamstring torques occurred in spite of the fact that the team played two games and trained twice per week during the entire season. No correlation between the fall in muscle strength and the injury rate was found. Although many injuries occur in ice hockey, the majority are minor ones that do not lead to absence from playing.

Does Swedish amateur boxing lead to chronic brain damage? 3. A retrospective clinical neurophysiological study.

The aim of the present study was to investigate possible chronic brain damage due to Swedish amateur boxing. Forty seven former amateur boxers, 22 with many (HM = high-matched) and 25 with few matches (LM = low-matched) during their career were examined and compared with two control groups of 25 soccer players and 25 track and field athletes in the same age-range. No severe EEG abnormality was found. There was a somewhat higher incidence of slight or moderate EEG deviations among HM-(32%, 7/22) and LM-(36%, 9/25) boxers than among soccer players (20%, 5/25) and track and field athletes (12%, 3/25). Brain electric activity mapping (BEAM), brainstem auditory evoked potential (BAEP) and auditory evoked P 300 potential (P 300) did not differ significantly between the groups. No neurophysiological variable was correlated to the number of bouts, number of lost fights or length of boxing career. Thus, no signs of serious chronic brain damage was found among the amateur boxers or the soccer players and the track and field athletes. However, it cannot be excluded that the EEG differences between the groups may be a sign of slight brain dysfunction in some of the amateur boxers.

Does Swedish amateur boxing lead to chronic brain damage? 1. A retrospective medical, neurological and personality trait study.

Sweden banned professional boxing in 1969 and has also considered banning amateur boxing. We therefore analysed possible chronic brain damage in 47 former amateur boxers who started their careers after the introduction of stricter Swedish amateur boxing rules. The boxers were compared with three control groups--25 soccer players, 25 track and field athletes and 19 conscripts. All athletes were interviewed about their sports career, medical history and social variables. They then underwent a physical and a neurological examination, including a mini-mental state examination. Personality traits were investigated and related to their platelet MAO activity in the athletes as well as in the conscripts. No significant differences were found between the groups in any of the physical or neurological examinations. All had a normal mini-mental state examination. Thus, results from these test methods did not reveal any signs of chronic brain damage from Swedish amateur boxing. Neither were any significant differences found with regard to platelet MAO activity, while significant differences were found in some of the social and personality traits variables.