Biomedical subjects

J Born

Publications and source records attributed to J Born.

246 records · Page 14Linked to original sources

PubMedDate not supplied

Vasopressin does not enhance memory processes: a study in human twins.

Behavioral effects of lysin-vasopressin (LVP) were investigated applying two paradigms from human experimental psychology. The first task was designed to simulate amnesic symptoms in normals. The second task addressed the emotional value of the items to be processed. Additionally, EEG recordings were used as indicators of the central nervous system effectiveness of LVP. Blood pressure and heart rate measured peripheral arousal. The co-twin control method was employed to increase experimental power. Contrary to the prediction of the vasopressin memory hypothesis none of the specific memory parameters was improved by LVP treatment. Changes in the electrical activity of the brain, but not in blood pressure and heart rate indicated central nervous system actions of LVP. However, interpretation of LVP effects in terms of memory processing seems not to be justified.

Adolescent↗

PubMedDate not supplied

Vasopressin and electrophysiological signs of attention in man.

Seventeen pairs of monozygotic twins, females and males, were tested in a dichotic listening task, containing several types of pips: standard and deviating target pips, which the subject either attended to, or not. Averaged auditory evoked potentials (AEPs) to the pips provided measures of different attentional processes. Furthermore, EEG power spectra, heart rate and blood pressure and behavioral performance were measured. Subjects received treatments (20 I.U. lysine-vasopressin vs. placebo) intranasally 48, 24, and 1 hour prior to the experimental sessions according to a co-twin control design. Whereas measures of voluntary selective attention remained unchanged by lysine-vasopressin (LVP) the peptide primarily affected an attentional mechanism responding in an automatic fashion to stimulus deviance. This effect was indicated by a substantial negative shift of the AEP amplitudes following deviating stimuli within the latency range of the N2/P2 components (about 200 msec post-stimulus). The effect seemed to be unrelated to modulations of cortical arousal after LVP.

Adolescent↗

PubMedDate not supplied

Effects of DGAVP on verbal memory.

Effects of DGAVP (desglycinamide-arginine-vasopressin, a synthetic vasopressin analog) on verbal memory were investigated in 13 healthy male volunteers. Ten word lists, each consisting of 15 words, were presented to the subjects who had to recall them according to a free recall paradigm. The total number of recalled words was not different between DGAVP and placebo treatment; but DGAVP had an effect on memory performance depending on the serial position of the words. It attenuated the primacy effect and enhanced the recency effect of memory performance. The pattern of changes after DGAVP may be consistent with an effect of the peptide on general arousal. Since the experiment was not designed to test influences of DGAVP on arousal, these considerations remain tentative.

Adult↗

PubMedDate not supplied

Vasopressin and oxytocin do not influence early sensory processing but affect mood and activation in man.

Effects of arginine-vasopressin (AVP) and oxytocin (OX) on brainstem and middle latency auditory-evoked potentials (BAEP and MAEP), reflecting early sensory processing within the specific auditory pathways and primary auditory cortex, were investigated. Additionally, subjects rated their feelings of activation and mood on an adjective check list (EWL). The experiments were undertaken in 12 healthy male volunteers, receiving either placebo, 0.15 IU AVP, 0.5 IU AVP or 0.5 IU OX as IV bolus injection according to a within-subject double-blind design. There were no consistent effects of AVP and OX on BAEPs and MAEPs. AVP decreased self-perceived deactivation, fatigue and arousal. Results do not suggest an effect of AVP and OX on early stages of sensory processing, but, consistent with previous studies, demonstrate changes towards increased (self-perceived) general activation following administration of these hormones.

Adult↗

PubMedDate not supplied

Behavioral effects of neurohypophyseal peptides in healthy volunteers: 10 years of research.

A short summary of behavioral studies on the effects of vasopressin and oxytocin published during the past decade is provided. Only studies using healthy volunteers as subjects were included. Among the studies reviewed, large differences exist with respect to design, procedure, treatment schedule and dose used. Results from the majority of the studies support that vasopressin and oxytocin affect central nervous functions in man after systemic administration. Since the hormonal influences do not appear to be consistently restricted to certain stages of stimulus processing but nonspecifically concern a great variety of cognitive functions, it is suggested that the influence of hypophyseal peptides on stimulus processing is mediated through an action on basic mechanisms involved in the general regulation of central nervous activation, i.e., on arousal systems that could also alter affective aspects of stimulus processing. The altogether moderate number of studies, so far, does not provide a sufficient data base justifying a clinical application of these peptides as nootropic treatments.

Behavior↗

PubMedDate not supplied

Selective influence of menstrual cycle on perception of stimuli with reproductive significance.

Sixteen healthy women (20-32 years) not taking oral contraceptives were tested at three phases of their menstrual cycles (menses, preovulatory phase, and midluteal phase). Another 16 women taking oral contraceptives served as age-matched controls, and were tested during menses and during phases corresponding to the preovulatory and midluteal phase. On each test occasion, perception was assessed of visual stimuli belonging to three categories: sex (nude men), babies, and stimuli related to body care. Also, meaningless syllables were given. Stimuli were presented by a tachistoscope. Presentation of each stimulus was repeated until the subject signaled recognition. Trials to recognition and correctness of the recognition response were recorded. In spontaneously cycling women effects of the phase of the menstrual cycle depended on the stimulus meaning: During the preovulatory phase, there was an increase in the number of correctly recognized sex stimuli (p < 0.05) and of stimuli falsely recognized as sex stimuli (p < 0.05). The number of stimuli falsely recognized as body care was reduced during this phase (p < 0.05). Moreover, during the luteal phase, the number of trials to recognition of baby stimuli was diminished (p < 0.01). In women taking contraceptives, no stimulus specific changes occurred, but correct recognition was generally improved during the luteal phase. Rather than supporting a general influence of the normal menstrual cycle on perceptual functions, the present results demonstrate that the effects of the menstrual cycle depend on the meaning of the stimulus with the perception of sexual stimuli, but not of stimuli related to maternal nurture, being improved during the preovulatory phase.

Adult↗

PubMedDate not supplied

Effects of sleep on the production of cytokines in humans.

The restorative functions of sleep may affect immunologic functioning. The present study examined the effects of sleep on stimulated cytokine release in 13 healthy men. The subjects spent 2 experimental nights in the sleep laboratory. In one condition, lights were turned off at 11:00 PM to enable sleep for 3.5 hours. Thereafter, they stayed awake till 7:00 AM. In the other condition, conversely, subjects stayed awake between 11:00 PM and 3:00 AM. Then, lights were turned off for a 3.5-hour phase of sleep. Blood was sampled every 30 minutes between 11:00 PM and 7:00 AM. Sleep was monitored by polysomnographic recordings. Release of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) was determined after stimulation of mononuclear cells with lipopolysaccharide from Escherichia coli. The release of IL-2 was stimulated with phytohemagglutinin. Compared with wakefulness, after 3 hours of sleep, production of TNF-alpha and IL-1 beta was substantially diminished (p < .01). Production of IL-2 was enhanced during sleep (p < .05), with this effect being limited to the second nocturnal sleep phase after 3:00 AM. Sleep-dependent changes in stimulated cytokine release were independent of changes in plasma cortisol concentrations. These results indicate a specific reducing effect of sleep (vs. wakefulness) on cytokine production by monocytes (TNF-alpha and IL-1 beta). The rather slow development of the effects calls for further studies to establish the exact time course of the influence of sleep on cytokine production.

Adult↗

PubMedDate not supplied

Adrenocorticotropin widens the focus of attention in humans. A nonliner electroencephalographic analysis.

OBJECTIVE: This study examined the effects of ACTH 4-10, a fragment of adrenocorticotropin (ACTH) with known central nervous system (CNS) activity, on the dimensional complexity of the ongoing electroencephalographic (EEG) activity. Stressful stimuli cause ACTH to be released from the pituitary, and as a neuropeptide ACTH may concurrently exert adaptive influences on the brain's processing of these stimuli. Previous studies have indicated an impairing influence of ACTH on selective attention. METHODS: Dimensional complexity of the EEG, which indexes the brain's way of stimulus processing, was evaluated while subjects performed tasks with different attention demands. Sixteen healthy men (23 to 33 years) were tested once after placebo and another time after administration of ACTH 4-10 (1.25 mg intravenously (i.v.), 30 minutes before testing). The EEG was recorded while subjects were presented with a dichotic listening task (consisting of the concurrent presentation of tone pips to the left and right ear). Subjects either a) listened to pips in both ears (divided attention), or b) listened selectively to pips in one ear (selective attention), or c) ignored all pips. RESULTS: Dimensional complexity of the EEG was higher during divided than selective attention. ACTH significantly increased the EEG complexity during selective attention, in particular over the midfrontal cortex (Fz, Cz). CONCLUSIONS: The effects support the view of a de-focusing action of ACTH during selective attention that could serve to improve the organism's adaptation to stress stimuli.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

Emotional memory formation is enhanced across sleep intervals with high amounts of rapid eye movement sleep.

Recent studies indicated a selective activation during rapid eye movement (REM) sleep of the amygdala known to play a decisive role in the processing of emotional stimuli. This study compared memory retention of emotional versus neutral text material over intervals covering either early sleep known to be dominated by nonREM slow wave sleep (SWS) or late sleep, in which REM sleep is dominant. Two groups of men were tested across 3-h periods of early and late sleep (sleep group) or corresponding retention intervals filled with wakefulness (wake group). Sleep was recorded polysomnographically. Cortisol concentrations in saliva were monitored at acquisition and retrieval testing. As expected, the amount of REM sleep was about three times greater during late than during early retention sleep, whereas a reversed pattern was observed for SWS distribution (P < 0.001). Sleep improved retention, compared with the effects of wake intervals (P < 0.02). However, this effect was substantial only in the late night (P < 0.005), during which retention was generally worse than during the early night (P < 0.02). Late sleep particularly enhanced memory for emotional texts. This effect was highly significant in comparison with memory for neutral texts (P < 0.01) and in comparison with memory after late and early wake intervals (P < 0.001). Cortisol concentration differed between early and late retention intervals but not between sleep and wake conditions. Results are consonant with a supportive function of REM sleep predominating late sleep for the formation of emotional memory in humans.

Adult↗

PubMedDate not supplied

Low frequency noise and stress: bronchitis and cortisol in children exposed chronically to traffic noise and exhaust fumes.

A correlation of respiratory diseases to traffic related air pollution and noise was observed in an interview study. Since in that study the exposure was subjectively assessed, in the present field study nitrogen dioxide as indicator for vehicle exhausts and the mean night-time noise level were measured outside the children's windows in representative locations. Based on these measurements each child was placed in one of the following categories: low, medium or high traffic immission (ambient emissions). The physician contacts due to bronchitis of 68 children were assessed retrospectively from the files of the participating paediatricians. Saliva samples were collected from all children and the cortisol concentration was estimated. Children under high noise exposure (L(night, 8h) = 54-70dB(A)) had in comparison to all other children significantly increased morning saliva cortisol concentrations, indicating an activation of the hypothalamus-pituitary-adrenal (HPA) axis. Analysing a subgroup of children without high noise exposure showed, that children with frequent physician contacts due to bronchitis did not have increased morning saliva cortisol. However, multiple regression analysis with stepwise exclusion of variables showed that bronchitis was correlated more closely to morning salvia cortisol than to traffic immissions. On the other hand, the rate of physician contacts due to bronchitis increased in a dose dependent manner and significantly with increasing traffic immissions. From these results it can be concluded that high exposure to traffic noise, especially at nighttime, activates the HPA axis and this leads in the long term to an aggravation of bronchitis in children. This seems to be more important than the effect of exhaust fumes on bronchitis symptoms. The results of the present study should be subjected to further investigation using specially designed studies.

Bronchitis↗

PubMedDate not supplied

Epidermal growth factor receptors in human tumors of the central nervous system.

Epidermal growth factor receptors (EGF-R) have been measured in human tumors of the Central Nervous System (CNS) by 125I EGF ligand binding. High affinity receptors (Ka congruent to 1 x 10(9) M-1) were detected in nearly all individual specimens of meningiomas and tumors of glial origin (astrocytomas, glioblastomas). The phosphotyrosine kinase activity associated with the EGF-R was evaluated by measuring the incorporation of gamma 32P-ATP, after immunoprecipitation of the receptor with the monoclonal antibody EGFRI. A good relationship was observed between the EGF-binding capacity and the autophosphorylation of the receptor, indicating that in most cases functional molecules of EGF-R were expressed on the tumor membranes. In the group of meningiomas, no relationship could be established between the EGF-R level and the histopathology of the tumors. Astrocytomas exemplify a progression of malignancy, from benign (low grade astrocytomas) towards an increased malignant phenotype (glioblastomas). In this group, our observations indicate a positive relationship between the EGF-R level and phosphokinase activity and the degree of malignancy.

Brain Neoplasms↗

PubMedDate not supplied

[Facio-craniostenosis].

Facio-craniostenosis. Facio-craniostenosis is associated with premature stenosis of one or several cranial sutures. The clinical variety is defined by the affected suture. In the complex forms, major disturbances of the anterior fossa of the cranial base are observed. Intracranial hypertension sometimes observed may lead to impairment of the function of the brain or the eyes. The authors have observed 73 children with craniostenosis and have operated upon 49 of them. Three types of methods have been used. The stress is made on the latest one combining advancement of the orbito-frontal "bandeau" and the regularization of the vault. Operating early is essential for prevention of functional sequellae. The optimal age for surgical treatment seems to be between 3 and 6 months. Complications have been remarkable benign.

Age Factors↗