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Biomedical subjects

O Ekeberg

Publications and source records attributed to O Ekeberg.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Suicide and attempted suicide among the elderly].

The suicide rate in Norway among persons older than 15 years has increased from 10/100,000 during the period 1965-67 to 18/100,000 during the period 1985-87. Attention has been focused in particular on the higher rates among young people, and not so much on the rates among the elderly. The suicide rate for males older than 70 years increased by 51% to 27/100,000 in the 20 year period, and is now at the same level as among the age group 20-69 years. The suicide rate for females older than 70 years increased by 68% to 7/100,000 during the same period. The suicide rate for females varies more with age, and is highest (15/100,000) in the age group 50-59. In 1989, 36 patients (75% females) older than 70 years were admitted to the Medical Department. Ullevål sykehus for self-poisoning. This is about twice as many as four years before. The annual rates of self-poisonings were 143/100,000 for females and 93/100,000 for males. The suicidal intention was much higher (61% suicidal attempts) among patients older than 70 years than among persons below this age (15%). In 44% of the cases the main problem preceding the self-poisoning was loneliness and isolation. The toxic agent was usually (56%) benzodiazepine hypnotics. The findings indicate that the suicide rates among the elderly in Norway will continue to increase, at least in the cities, where loneliness and isolation is an increasing problem.

Age Factors↗
PubMed1991

A computer based model for realistic simulations of neural networks. I. The single neuron and synaptic interaction.

The use of computer simulations as a neurophysiological tool creates new possibilities to understand complex systems and to test whether a given model can explain experimental findings. Simulations, however, require a detailed specification of the model, including the nerve cell action potential and synaptic transmission. We describe a neuron model of intermediate complexity, with a small number of compartments representing the soma and the dendritic tree, and equipped with Na+, K+, Ca2+, and Ca2+ dependent K+ channels. Conductance changes in the different compartments are used to model conventional excitatory and inhibitory synaptic interactions. Voltage dependent NMDA-receptor channels are also included, and influence both the electrical conductance and the inflow of Ca2+ ions. This neuron model has been designed for the analysis of neural networks and specifically for the simulation of the network generating locomotion in a simple vertebrate, the lamprey. By assigning experimentally established properties to the simulated cells and their synapses, it has been possible to verify the sufficiency of these properties to account for a number of experimental findings of the network in operation. The model is, however, sufficiently general to be useful for realistic simulation also of other neural systems.

Computer Simulation↗
PubMed1991

Suicide and other causes of death in a five-year follow-up of patients treated for self-poisoning in Oslo.

This 5-year follow-up study includes all patients (n = 934; 50% females) treated for self-poisoning in Oslo during 1 year. Seventeen percent were considered suicide attempts upon admission, 25% among the nonabusers and 8% among the abusers. At follow-up, 122 patients were dead (61% males). The mortality rate was highest among the abusers. The mortality rate was similar (13%) among those who were considered to be suicidal on admittance and those who were not. The causes of death were suicide (28%), opiate abuse (16%), heart disease (14%), accidents or wounds (11%), alcoholism (9%) and others (22%). The standard mortality rate was highly increased in all groups (8 times on average), highest among the female opiate abusers, whose rate was 63 times higher than expected. The increased suicide rates (87 times for females, 27 times for males), however, may be a more relevant measure of mental morbidity than the standard mortality rate. Logistic regression analysis demonstrated that male sex, age above 50 years and the lowest social group were factors on admission associated with death in the follow-up period. Age above 50 years and suicidal attempt on admission were associated with subsequent suicide. The study strongly supports the idea of self-destructiveness and slow suicide in substance abuse.

Adult↗
PubMed1991

Computer simulations of N-methyl-D-aspartate receptor-induced membrane properties in a neuron model.

1. To evaluate the role of N-methyl-D-aspartate (NMDA) receptors in simulations of the lamprey spinal locomotor network, we developed a computer-simulated electrical model of a neuron that contains NMDA channels in addition to voltage-gated Na+, K+, and Ca2+ channels and Ca(2+)-activated K+ channels [K(Ca) channels]. 2. The voltage dependence of the Mg2+ block of the Na(+)-K+ current flow through the NMDA channel was modeled according to a scheme of open-channel block. To account for the regulation of K(Ca) channels by NMDA and membrane voltage, we modeled two separate Ca2+ pools that had different voltage dependencies and dynamics. 3. Pacemaker-like membrane potential oscillations could be elicited in the model neuron, which resembled those observed experimentally in the presence of bath-applied NMDA and tetrodotoxin. The effect of changing different channel parameters were tested to determine under which conditions such membrane potential oscillations could occur. 4. The oscillation amplitude was determined by the potential levels at which the NMDA channels and voltage-dependent K+ channels, respectively, were activated. The oscillation frequency and the relative durations of the de- and hyperpolarized phases of the oscillations were determined by the balance between the depolarizing (NMDA channels) and hyperpolarizing [K(Ca) channels] currents. 5. Simulated alterations of the Mg2+ concentration and the K+ conductance as well as injection of constant current caused changes of the oscillations corresponding to those observed experimentally. The de- and hyperpolarizing phases could be reset by brief current pulses. 6. We conclude that the present model can account for the effects of bath-applied NMDA on spinal neurons. This permits an incorporation of NMDA-receptor-mediated properties in simulation models of the lamprey locomotor network.

Action Potentials↗
PubMed1990

Childhood traumas and psychosocial characteristics of 50-year-old men with essential hypertension.

The aim of the present study was to describe childhood traumas and other psychosocial characteristics of middle-aged men with never-treated essential hypertension. Hypertensive (N = 17) and normotensive (N = 18) 50-yr-old men were selected from the Oslo Study of Cardiovascular Diseases based on their age, sex, blood pressure and otherwise healthy condition without chronic medication. They were interviewed semistructurally by a psychiatrist who was unaware of their blood pressure status. Eleven hypertensives and five normotensives (p less than 0.05) had experienced considerable traumas in childhood, e.g. death of a parent, psychotic parent, separation from one or both parents, or beating by an alcoholic father. The hypertensives had fewer siblings and fewer sons than the normotensives (p less than 0.05). The normotensives were better educated; 12 had finished at least 12 yr in school as opposed to one hypertensive (p less than 0.01). The normotensives' parents (p less than 0.05) and spouses (p less than 0.001) were better educated than the hypertensives'. The normotensives' yearly income was higher (p less than 0.05). The hypertensives showed more Type A behaviour patterns (p less than 0.05) and lower Spielberger State Curiosity (p less than 0.05). Although the groups were small, they were rigorously characterized. These results therefore suggest that middle-aged men with essential hypertension have more childhood traumas and lower educational and income levels and that these social characteristics are associated with Type A behaviour patterns. The study favours a psychosocial understanding of the pathogenesis of essential hypertension.

Arousal↗
PubMed1990

Effects of beta 1- and beta 2-blockade on blood pressure and sympathetic responses to flight phobia stress.

Cardiovascular and sympathoadrenal effects of short-term oral treatment with beta 1-blockade (atenolol, 50 mg, administered two times) and beta 2-blockade (ICI 118,551, 50 mg, administered three times) were compared with placebo during actual flying in subjects with flight phobia (n = 34). beta 1-Blockade lowered resting blood pressure and heart rate and prevented a heart rate response but not a blood pressure response to this psychologic stress. beta 2-Blockade minimally lowered resting heart rate and prevented a heart rate response, but it failed to lower resting blood pressure or blood pressure response to the stress. Plasma epinephrine increased with all three treatments and more with beta 1-blockade than with placebo. Plasma norepinephrine decreased with administration of beta 2-blockade. Thus neither beta 1- nor beta 2-blockade prevents an increase in blood pressure during acute flight phobia stress. Increased plasma epinephrine seems to be the sympathetic variable that is closest related to this increase in blood pressure. Norepinephrine may be less consistently related to the blood pressure rise during flight phobia stress as shown by the decrease in plasma norepinephrine with administration of beta 2-blockade.

Administration, Oral↗
PubMed1990

Correlations between psychological and physiological responses to acute flight phobia stress.

Exposure of phobic subjects to real-life psychological stress may induce a high level of anxiety and be better than laboratory experiments for studies of physiological responses to psychological stress in human research. Therefore, by introducing natural psychological stress, i.e. actual flying in subjects with flight phobia (n = 23), the present study aimed at testing the hypothesis that there is, during mental stress, a direct relationship between the level of anxiety and the responses in the physiological variables blood pressure, heart rate and plasma catecholamines. Plasma adrenaline, heart rate, blood pressure and perceived anxiety measured by three different scales increased highly significantly during flight whereas plasma noradrenaline did not change. No direct relationship was found between the physiological and psychological variables. Thus, the physiological responses to natural psychological stress in terms of phobic anxiety may be definite, but the way the responses are related is less clear.

Adult↗
PubMed1989

[Self-poisoning in Northwest Norway in 1975-1984].

During the ten-year period 1975-84, 251 patients were hospitalized because of self poisoning in Nordmøre, the northern part of Møre and Romsdal county. During the five last years, there was a large increase in hospital admittances because of self poisoning, especially of persons below the age of thirty. Men dominated in the age group 20-30 years, and women in the age group 15-20 years. There was a significant correlation between the number of unemployed and the number of self poisonings through out the ten-year period.

Adolescent↗
PubMed1989

[Self-poisoning in Northwest Norway in 1984. A follow-up after 6 months. A prospective study].

During the one-year period of study, 37 patients were admitted to the medical department, Kristiansund hospital, because of self poisoning. Mixed intoxications dominated, especially combinations of benzodiazepines and alcohol. One patient died. Interpersonal conflicts were stated as the main reason for the self poisoning. Five patients were considered suicidal. 27 patients were followed up six months later. A majority considered both their social and mental situation to be better than at the time of the self poisoning episode, and had reduced consumption of alcohol and drugs.

Adolescent↗
PubMed1989

Plasma catecholamines in some airline passengers.

Assuming that the act of flying may provoke mental stress and increments in plasma catecholamines, in-flight plasma catecholamines were compared in two groups of passengers: a group of ordinary passengers (Group 1, n = 15) and a group of passengers who had just completed a cognitive, behavioural treatment programme against flight phobia (Group 2, n = 13). No difference in catecholamines was observed between the groups. However, 10 of the subjects in Group 1 and 12 of the subjects in Group 2 had in-flight plasma adrenaline higher than the highest mean +2 SD (above 0.40 nmol/l) of resting plasma adrenaline observed in healthy subjects in a long series of studies previously or simultaneously done in our laboratory. Subjects in Group 2 (n = 12) showed an average decrease of 50% from in-flight to post-flight plasma adrenaline. Plasma noradrenaline values were not elevated compared to normal resting levels, but an average reduction of 24% was observed between in-flight and post-flight in Group 2. We could not detect any difference between passengers treated for flight phobia and ordinary passengers. However, in-flight plasma catecholamines, particularly adrenaline, seem to be elevated in some airline passengers of various backgrounds. The most plausible explanation seems to be the discomfort and fear some people feel when flying; however, we cannot exclude that the physiological act of flying per se increased plasma catecholamines. Relatively larger variations in plasma adrenaline compared to noradrenaline may favour the first of these two possible explanations.

Adult↗
PubMed1987

Effect of regulatory withdrawal of drugs and prescription recommendations on the pattern of self-poisonings in Oslo.

A two-year prospective study of 1350 admissions for self-poisoning, covering the Oslo area was undertaken to identify the sources of the toxic agents. After the first year of the study, four barbiturates were withdrawn from the Norwegian market and recommendations were made by the Health Authorities to promote more restrictive attitudes when prescribing psychoactive drugs. The patterns of self-poisonings in the two periods were compared. The withdrawal of four barbiturates resulted in a 55% decrease in the rate of barbiturate poisonings in general (p less than 0.001). No increase could be detected in the rate of self-poisoning with benzodiazepines and other hypnotics, but the incidence of self-poisonings with antidepressants (p less than 0.01) and neuroleptics (p less than 0.01) was found to have increased significantly. The regulations and recommendations resulted in a significant decrease in drugs obtained from doctors randomly consulted (p less than 0.01), and a significant increase in drugs prescribed by psychiatrists (p less than 0.01). Drugs obtained from non-medical sources increased from 28% in the first period to 33.2% in the second. The total number of admissions and toxic agents taken remained unaltered. Thus, regulatory measures can influence the pattern of self-poisoning but do not seem to influence the tendency to abuse drugs or to take an overdose.

Adolescent↗
PubMed1986

Self-poisoning and the menstrual cycle.

A study of the menstrual cycle phase on day of admission was conducted on 156 women with regular menstruation admitted for self-poisoning to a medical department. No relation of statistical significance was found between the day of self-poisoning and the menstrual cycle phase. This was also the case when a distinction was made between suicidal and non-suicidal attempts and between the main toxic agents taken. The findings are partly in contrast to earlier investigations.

Adolescent↗