Biomedical subjects

M B Andersen

Publications and source records attributed to M B Andersen.

At least 19 recordsLinked to original sources

PubMed2005

The substituted (S)-3-phenylpiperidine (-)-OSU6162 reduces apomorphine- and amphetamine-induced behaviour in Cebus apella monkeys.

Low affinity dopamine (DA) D2 antagonists such as the substituted (S)-3-phenylpiperidine (-)-OSU6162 have been proposed to be putative antipsychotic agents not endowed with extrapyramidal side effects (EPS). In the present study we investigated the effects of (-)-OSU6162 on (-)-apomorphine and d-amphetamine-induced behaviours in EPS sensitised Cebus apella monkeys. (-)-OSU6162 was administered subcutaneously in doses of 1, 3, 6 and 9 mg/kg alone and in combination with (-)-apomorphine (0.25 mg/kg) or d-amphetamine (0.5 mg/kg). (-)-OSU6162 inhibited (-)-apomorphine-(1-9 mg/kg) as well as d-amphetamine (3-9 mg/kg)-induced arousal and stereotypy. EPS did not occur when (-)-OSU6162 was administered in combination with (-)-apomorphine or d-amphetamine. However, when (-)-OSU6162 was administered alone, dystonia was observed at high doses (6 and 9 mg/kg) in two out of six monkeys. The present study shows that (-)-OSU6162 can inhibit (-)-apomorphine-induced behaviours in non-human primates at doses that do not cause EPS. When (-)-OSU6162 was tested against d-amphetamine-induced behaviours a separation between dose levels that inhibit d-amphetamine effects and cause EPS was not observed. The data further substantiate a role for low affinity DA D2 antagonists in the pharmacological treatment of psychosis.

Amphetamine↗

PubMed2005

Work-related stressors, depression and quality of life in Danish managers.

BACKGROUND: By use of valid questionnaires to investigate work-related stress and distress in Danish managers. METHODS: The survey focused on members of the Danish Association of Managers and Executives who no longer were active (former managers' group). Acting managers (active managers' group) served as controls. Questionnaires measuring stressors at work and general life events were used. For the measurement of distress, scales for depression and quality of life were used. RESULTS: The Mokken analysis proved the validity of the questionnaires, i.e. their summed-up total scores were sufficient statistics. No differences were found between former (n = 1,256) and active managers (n = 942) as to life events. Approximately 20% of former managers were at risk of depression and 12% had developed major depression. Among the specific work-related stressors were role overload, lack of team spirit and lack of social support. The percentage of active managers at risk of or suffering from major depression did not differ significantly from the Danish general population. Approximately 37% of the former managers had a decreased well-being. Alcohol use was found to be significantly associated with depression. CONCLUSION: The study identified specific work-related stressors in managers, 12% of whom developed a major depression.

Adaptation, Psychological↗

PubMed2003

Cebus apella, a nonhuman primate highly susceptible to neuroleptic side effects, carries the GLY9 dopamine receptor D3 associated with tardive dyskinesia in humans.

Tardive dyskinesia (TD) is a severe side effect of traditional neuroleptics affecting a considerable number of schizophrenic patients. Accumulating evidence suggests the existence of a genetic disposition to TD and other extra pyramidal symptoms (EPS) most strongly linked to a ser/gly polymorphism in position 9 of the D3 dopamine receptor gene (DRD3). The Cebus apella monkey is the favored animal model to study TD and other EPS because of its high susceptibility to side effects of neuroleptics. We therefore determined the sequence of the DRD3 gene in this species and compared it with that of humans. We found that the highly TD susceptible C. apella monkey (n=21) carries the gly9/gly9 DRD3 genotype that has been associated with TD in humans. Contrarily, C. apella did not carry the ser23 5HT2C allele that has been reported to increase TD susceptibility in humans.

Amino Acid Substitution↗

PubMed2002

The adenosine A2A receptor agonist CGS 21680 exhibits antipsychotic-like activity in Cebus apella monkeys.

The adenosine A2A receptor agonist CGS 21680 has shown effects similar to dopamine antagonists in behavioural assays in rats predictive for antipsychotic activity, without induction of extrapyramidal side-effects (EPS). In the present study, we examined whether this functional dopamine antagonism and lack of EPS in rodents could also be observed in non-human primates. We investigated the effects of CGS 21680 on behaviours induced by D-amphetamine and (-)-apomorphine in EPS-sensitized Cebus apella monkeys. CGS 21680 was administered s.c. in doses of 0.01, 0.025 and 0.05 mg/kg, alone and in combination with D-amphetamine and (-)-apomorphine. The monkeys were videotaped after drug administration and the tapes were rated for EPS and psychosis-like symptoms. CGS 21680 decreased apomorphine-induced behavioural unrest, arousal (0.01-0.05 mg/kg) and stereotypies (0.05 mg/kg) while amphetamine-induced behaviours (unrest, stereotypies, arousal) were unaffected. EPS were not observed at any dose. At 0.05 mg/kg CGS 21680 produced vomiting. The two lower doses did not produce observable side-effects. Though the differential effect on amphetamine- and apomorphine-induced behaviours is intriguing, CGS 21680 showed a functional anti-dopaminergic effect in Cebus apella monkeys without production of EPS. This further substantiates that adenosine A2A receptor agonists may have potential as antipsychotics with atypical profiles.

Adenosine↗

PubMed2001

Direct comparison of visual cortex activation in human and non-human primates using functional magnetic resonance imaging.

We report a technique for functional magnetic resonance imaging (fMRI) in an awake, co-operative, rhesus macaque (Macaca mulatta) in a conventional 1.5T clinical MR scanner, thus accomplishing the first direct comparison of activation in visual cortex between humans and non-human primates with fMRI. Activation was seen in multiple areas of striate and extra-striate visual cortex and in areas for motion, object and face recognition in the monkey and in homologous visual areas in a human volunteer. This article describes T1, T2 and T2* values for macaque cortex, suitable MR imaging sequences, a training schedule, stimulus delivery apparatus and restraining hardware for monkey fMRI using a conventional 19 cm knee coil. Much of our understanding of the functional organization of the primate brain comes from physiological studies in monkeys. Direct comparison between species using fMRI such as those described here will help us to relate the wealth of existing knowledge on the functional organization of the non-human primate brain to human fMRI.

Adolescent↗

PubMed2001

The ethical beliefs and behaviours of Victorian fitness professionals.

A survey based on those employed by Petitpas, Brewer, Rivera, and Van Raalte (1994), Pope, Tabachnick, and Keith-Spiegel (1987), Pope and Vetter (1992), and Tabachnick, Keith-Spiegel, and Pope (1991) was used to investigate the ethical beliefs and behaviours of Victorian fitness professionals. Although there is evidence that Victorian fitness professionals are knowledgeable about some general ethical principles, the results of this study suggest that there is some lack of consensus among Victorian fitness professionals about the ethical appropriateness of a number of complex issues relating to business practices, confidentiality, dual relationships, and personal and professional boundaries. The findings suggest there is a need to improve the professional and ethical education of fitness professionals and to develop comprehensive ethical principles and a code of conduct that is relevant to the individuals working in the Australian fitness profession.

Adult↗

PubMed2001

Sport psychology service delivery: staying ethical while keeping loose.

Although the parent discipline of sport psychology is psychology, the delivery of sport psychology services has its main roots in physical education and sports science (motor learning and control, skill acquisition). Thus, sport psychologists may look more like coaches than they look like clinicians or counselors. In this article, the authors trace the evolution of sport psychology services and contrast the temporal, spatial, and delivery issues of applied sport psychology with more mainstream counseling and clinical psychology. The looser boundaries of sport psychologist practice have both benefits and dangers, and the authors offer some examples to professional psychologists who are thinking of expanding their delivery of service to athletes and coaches.

Confidentiality↗

PubMed2001

Exercise and multiple sclerosis: physiological, psychological, and quality of life issues.

The case for the benefits of physical activity has been well documented in healthy individuals, and the potential for reducing the risk of mental and physical ill health is substantial. Yet, individuals with multiple sclerosis (MS) have long been advised to avoid participation in exercise in order to minimise the risk of exacerbations and symptoms of fatigue. There is, however, increasing interest in how acute and chronic exercise affect physiological and psychological functioning in MS. Much of the research has examined physiological tolerance to exercise and focused on responses in terms of heart rate, blood pressure, cardiorespiratory fitness, muscle function, and symptom stability. Little research has focused on understanding how exercise affects psychosocial functioning and brings about changes in depression, affect, mood, well-being, and quality of life. This paper provides a summary of the research exploring the efficacy of physical activity for people with MS. In addition, the key issues that face clinical practice are examined, and considerations for research are discussed.

Autonomic Nervous System↗

PubMed2000

Physiotherapists' and male professional athletes' views on psychological skills for rehabilitation.

In the literature on the psychological aspects of rehabilitation from athletic injury, several studies in North America have focused on athletic trainers' roles as physical and psychological caregivers for injured athletes. Wiese, Weiss, and Yukelson (1991) examined the views of athletic trainers on the psychological characteristics that distinguished athletes who coped well, versus those who coped poorly with rehabilitation, and also sought athletic trainers opinions on the role of psychological skills in injury rehabilitation. This study replicated the Wiese et al. (1991) study with Australian physiotherapists and extended it to include the viewpoints of professional basketball players. The results indicated the importance attached to communication and motivation by both physiotherapists and athletes in the rehabilitation process. Both athletes and physiotherapists did not, however, think psychological skills such as relaxation or imagery techniques to be particularly useful tools in the recovery process.

Adaptation, Psychological↗

PubMed2000

What exercise and sport scientists don't understand.

The power of research design in studies published in the Australian Journal of Science and Medicine in Sport (AJSMS: now the Journal of Science and Medicine in Sport) for the years 1996 and 1997 were analysed for their ability to detect small, medium, and large effects according to Cohen's (1988) conventions. Also examined were the reporting and interpreting of effect sizes and the control for experiment-wise (EW) Type I error rates. From the two years of articles, 29 studies were analysed, and power was computed on 108 different tests of significance. The median power of the studies to detect small, medium, and large effects were .14, .65 and .97, respectively. These results suggest that exercise and sport science research, at least as represented in AJSMS, is probably underpowered and may be limited in detecting small effects, has a better, but still underpowered, chance of detecting medium effects, and has adequate power principally for detecting large effects. The reporting of effect sizes was rare, and adequate interpretation of them was even rarer. The mean EW Type I error rate for all studies was .49. The analyses conducted suggest that much research in exercise science may have substantial Type I and Type II errors. An appeal is made for exercise scientists to conduct power analyses, control for EW error, exercise caution in the interpretation of nonsignificant results, and examine, report, and interpret effect sizes rather than solely rely on p values to determine whether significant changes occurred or significant relationships exist.

Data Interpretation, Statistical↗

PubMed2000

Heart rate-perceived exertion relationship during training and taper.

BACKGROUND: Examine the heart rate-perceived exertion (HR-RPE) relationship under conditions of high-intensity training and taper. METHODS: Experimental design and participants: prospective with collegiate cyclists (n=11) completed six weeks of high-intensity interval training, followed by a one-week taper. INTERVENTIONS: participants completed a high-intensity training regimen along with graded exercise tests (GXT) throughout the training and the taper. MEASURES: heart rates (HR) and ratings of perceived exertion (RPE) were recorded following each stage of the GXTs. Scores on GXTs were also recorded. RESULTS: . The HR-RPE relationship during GXTs changed over the course of the training with greater RPEs for a given HR at the end of the training compared to the beginning. The most powerful predictors of the performance response to the taper were training induced changes in the HR-RPE relationship and decreases in HR for a given power output. Those individuals who reported higher RPEs for lower HRs were more likely to have better performance responses to taper (r=0.72) as were those who had larger changes in the HR-power output relationship (r=0.76). CONCLUSIONS: These results indicate that changes in the HR-RPE relationship during high-intensity training may be used to monitor the magnitude of overreaching that is necessary for a positive response to a taper. For coaches and athletes, the HR-RPE ratio may be a practical measure for monitoring an aspect of fatigue associated with high-intensity training.

Adult↗

PubMed1999

Specific behavioral effects related to age and cerebral ischemia in rats.

Rats at 4, 14, and 20 months of age were subjected to permanent occlusion of the left middle cerebral artery (MCAO) and the effects of age and ischemia assessed in tests for spatial learning (Morris' water maze), social behavior, olfactory learning, exploratory behavior, and motor function. Furthermore, the extent of ischemic damage to the brain of rats of 5 and 19 months of age was studied. An age-related decline in water-maze performance was observed, and aged rats were less agile, less explorative, and less frequently engaged in social interactions than young rats. After ischemia, mild memory impairment was observed in old rats, while changes in some exploratory behaviors were observed in young rats. Neuropathological analyses revealed a variable and limited degree of infarction in the piriform cortex and the insular cortex with no difference between age groups. In conclusion, the present study confirmed and extended current data on behavioral differences between young and old rats. MCAO had limited influence on the tested behaviors.

Aging↗

PubMed1999

Athletic injury, psychosocial factors and perceptual changes during stress.

In this study, we measured changes in state anxiety, visual perception and reaction time during stress among 196 collegiate athletes participating in 10 sports. The athletes also completed measures of life events and social support at the beginning of their seasons. Measures of life events stress, social support, perceptual changes and changes in reaction time during stress were used as predictors of the number of injuries. For the entire sample, the only significant predictor of injury was negative life events stress (R = 0.45, P < 0.001). Following the suggestions of Smith et al., simple correlations were performed for those with least social support (bottom 33%, n = 65). Among this group, those individuals with more negative life events and greater peripheral narrowing during stress incurred more injuries than those with the opposite profile. Our findings are in line with the model of Andersen and Williams, in that those individuals who were low in a variable that buffers stress responsivity (i.e. social support), their negative life events and peripheral narrowing under stress (large and medium effect sizes, respectively) were substantially related to their number of injuries.

Adult↗

PubMed1998

[Stab and cut lesions among general practitioners in the county of Funen].

In a questionnaire sent out to general practitioners (GP) in the County of Funen they reported a yearly incidence of lesions penetrating the skin of 1.2 per practitioner. Approximately half of these lesions were potentially infectious. Sixty percent of the lesions were due to accidents involving needles. Only 52% of the GPs with the risk of a potentially infectious lesion tried to prevent infection. We estimate that the risk of becoming infected with HIV or Hepatitis-B infection is very low. It is necessary to get GPs to change procedures in an attempt to minimize the risk.

Accidents, Occupational↗

PubMed1998

Impairment of working memory in the T-maze after transient global cerebral ischemia in the Mongolian gerbil.

Using a T-maze, the influence of transient global cerebral ischemia on working memory in gerbils was investigated. Furthermore, it was examined whether a correlation exists between impairment in choice accuracy in the T-maze and neuron loss in the hippocampus. In two experiments, male Mongolian gerbils were tested in a previously learned delayed alternation T-maze task 1 week after a 4 min occlusion of the common carotid arteries. In both experiments memory was significantly impaired and in the second experiment, where the design allowed a separation between working and reference memory deficits, a selective impairment in working memory was seen. The results suggest that ischemia-induced disruption of delayed alternation in the T-maze in gerbils is a model which is relevant to the clinical manifestations of vascular dementia.

Animals↗

PubMed1997

Aseptic loosening of BonelocR cemented hip prostheses.

We present a systematic clinical and radiographic study of 147 patients who had total hip replacements from February 1992 to May 1993. BonelocR cement was used in 108, and PalacosR cement with gentamicin in 39 patients who had an increased risk of infection. At follow-up after 24 to 39 months, 26 cases with BonelocR cement had failed; there were no clinical failures in the PalacosR group.

Adult↗

PubMed1997

Transient cerebral ischemia inhibits juvenile recognition in the Mongolian gerbil.

This study introduces a social recognition test for Mongolian gerbils and describes the effect of transient global cerebral ischemia in this model. Adult male gerbils were exposed to an unfamiliar juvenile stimulus animal in two successive trials. The difference between the first and second exposures in duration of social investigation of the stimulus animal was used as a measure of social recognition. Recognition of the stimulus animal was seen after interexposure intervals (IEI) of 5 and 30 min, but not after 120 min. This is in concordance with data obtained in rats in a similar model. The capacity for social recognition was subsequently investigated in gerbils 1 week after 0 (sham), 4, or 8 min of bilateral occlusion of the common carotid arteries. An IEI of 30 min was used, as this IEI was within the time limit for recognition of the stimulus animal. Social recognition was impaired in both occlusion groups. The results suggest that the juvenile recognition test is a suitable model for testing amnesia in gerbils and that social olfactory memory is impaired by global cerebral ischemia.

Animals↗

PubMed1997

Postischemic hyperactivity in the Mongolian gerbil correlates with loss of hippocampal neurons.

Gerbils show a postischemic increase in locomotor activity that correlates to the extent of neuron loss in the hippocampal CA1 subfield. It has been suggested that this hyperactivity is predictive of neuron loss in the CA1. In this study the correlation between postischemic hyperactivity and neuron loss in several hippocampal subfields was investigated, and the theory that the hyperactivity is due to a reduced ability for spatial navigation was evaluated. Significant correlations were found between hyperactivity and neuron loss in several hippocampal subfields; the correlation was stronger for the CA3 than for the CA1 subfield, suggesting that postischemic hyperactivity can be used as a predictor of neuron loss in the CA3 rather than in the CA1. From observations of the pattern of hyperactivity within the test arenas and during the test period, this study challenges the spatial mapping theory of postischemic hyperactivity.

Animals↗