Biomedical subjects

J Oehler

Publications and source records attributed to J Oehler.

At least 19 recordsLinked to original sources

PubMed2005

[Heat stroke with alpha coma. A case report].

We report the case of a near-fatal heat stroke in a 41-year-old patient. The comatose patient had a body core temperature of 41.5 degrees C. The clinical course was complicated by systemic inflammatory response syndrome and multiorgan failure. The EEG showed an alpha coma that did not react to external stimuli and, in general, has a poor prognosis. The patient regained consciousness and was discharged from our intensive care unit after 16 days. In the further course cerebral toxoplasmosis developed which was treated with a combination therapy of sulfadiazine and pyrimethamine. The patient was transferred to a neurorehabilitation clinic with a moderate neurological deficit 65 days after heat stroke onset.

Adult↗

PubMed2004

Does acute occlusion of the carotid T invariably have a poor outcome?

OBJECTIVE: To evaluate the prognosis of patients with acute occlusion of the carotid T. METHODS: The authors studied 42 consecutive patients with acute carotid T occlusion, age 66 (59 to 74) years (median [interquartile range]). T occlusion was diagnosed with transcranial Doppler sonography (TCD; n = 11) and MR (n = 28) or CT (n = 3) angiography. Final infarction size was evaluated on follow-up CT 3 to 7 days after symptom onset and recanalization by follow-up TCD 24 to 36 hours after symptom onset. RESULTS: NIH Stroke Scale (NIHSS) score on admission was 18 (16 to 20). Final infarct size was one-third or less of the middle cerebral artery (MCA) territory in 11, greater than one-third but less than or equal to two-thirds of the MCA territory in 10, and greater than two-thirds of the MCA territory in 21 patients. Modified Rankin Scale (mRS) score 6 months after stroke onset was 2 in 7 (17%), 3 in 2 (5%), 4 in 13 (31%), 5 in 7 (17%), and 6 in 13 (31%) patients. Complete or partial MCA recanalization within 24 hours after symptom onset was observed in 12 of 18 patients treated with thrombolysis and 4 of the remaining 24 patients (p = 0.001) and was associated with better clinical outcome (mRS 2, recanalization 6/7 [86%]; mRS 3 to 5, recanalization 8/22 [36%]; mRS 6, recanalization 2/13 [15%]; p = 0.01). Recanalization and NIHSS score on admission were independent predictors of outcome. CONCLUSIONS: Acute carotid T occlusion does not necessarily carry a poor prognosis. IV thrombolysis frequently results in recanalization, which is related to a better clinical outcome and smaller final infarction size.

Acute Disease↗

PubMed2003

Influence of reboxetine on salivary MHPG concentration and cognitive symptoms among patients with alcohol-related Korsakoff's syndrome.

This study is based on the hypothesis of a paraventricular cerebral noradrenaline deficit in alcoholic Korsakoff's syndrome. In a randomized open study the effects of a 4-week treatment with the selective noradrenaline reuptake inhibitor reboxetine on (1) the salivary concentration of the noradrenaline metabolite MHPG and (2) changes in cognitive performance measured by the Mini Mental Status Test were examined. The study group consisted of 105 patients diagnosed with alcohol-related Korsakoff's syndrome (ICD-10: F10.6). Korsakoff's patients showed a reduced concentration of salivary MHPG compared to healthy controls; this reduction did not correlate with the results of the Mini Mental Status Test. An increase in salivary MHPG was found together with an improvement in the Mini Mental Status Test both in the verum group treated with reboxetine and in the control group upon completion of the 4-week study. However, a subgroup with a shorter duration of disease (<1 year) was found to profit significantly from reboxetine treatment, as shown by improvements in cognitive performance.

Alcohol Amnestic Disorder↗

PubMed2003

[Dissection of four cerebral arteries after protracted birth].

A 37-year-old woman suffered from middle cerebral artery infarction secondary to dissection of the left internal carotid artery. Nine days before, a cesarean section had been performed on her after 20 h of unsuccessful labor. Cerebral angiography at admission revealed no further vascular abnormalities. A few days later, however, the patient developed additional dissections of the right internal carotid artery and both vertebral arteries. Pregnancy, childbirth, and a history of rheumatoid arthritis in this patient may have contributed to the dissections; however, due to the unknown etiology of cervical dissections, the pathogenetic contribution of all of these factors is incompletely understood.

Adult↗

PubMed2003

[Bilateral vertebral artery dissection after chiropractic treatment].

A 31-year-old woman suffered a brainstem infarction secondary to chiropractic neck manipulation. A dissection of both vertebral arteries could be demonstrated by MR tomography. This case report should alert therapists to be aware of vertebrobasilar complications after spinal manipulations.

Adult↗

PubMed2002

CT and diffusion-weighted MR imaging in randomized order: diffusion-weighted imaging results in higher accuracy and lower interrater variability in the diagnosis of hyperacute ischemic stroke.

BACKGROUND AND PURPOSE: Diffusion-weighted MRI (DWI) has become a commonly used imaging modality in stroke centers. The value of this method as a routine procedure is still being discussed. In previous studies, CT was always performed before DWI. Therefore, infarct progression could be a reason for the better result in DWI. METHODS: All hyperacute (<6 hours) stroke patients admitted to our emergency department with a National Institutes of Health Stroke Scale (NIHSS) score >3 were prospectively randomized for the order in which CT and MRI were performed. Five stroke experts and 4 residents blinded to clinical data judged stroke signs and lesion size on the images. To determine the interrater variability, we calculated kappa values for both rating groups. RESULTS: A total of 50 patients with ischemic stroke and 4 patients with transient symptoms of acute stroke (median NIHSS score, 11; range, 3 to 27) were analyzed. Of the 50 patients, 55% were examined with DWI first. The mean delay from symptom onset until CT was 180 minutes; that from symptom onset until DWI was 189 minutes. The mean delay between DWI and CT was 30 minutes. The sensitivity of infarct detection by the experts was significantly better when based on DWI (CT/DWI, 61/91%). Accuracy was 91% when based on DWI (CT, 61%). Interrater variability of lesion detection was also significantly better for DWI (CT/DWI, kappa=0.51/0.84). The assessment of lesion extent was less homogeneous on CT (CT/DWI, kappa=0.38/0.62). The differences between the 2 modalities were stronger in the residents' ratings (CT/DWI: sensitivity, 46/81%; kappa=0.38/0.76). CONCLUSIONS: CT and DWI performed with the same delay after onset of ischemic stroke resulted in significant differences in diagnostic accuracy. DWI gives good interrater homogeneity and has a substantially better sensitivity and accuracy than CT even if the raters have limited experience.

Acute Disease↗

PubMed2001

Behavioral and neurochemical effects of anpirtoline and citalopram in isolated and group housed mice.

Acute effects of serotonergic drugs acting via different mechanisms were investigated by a social interaction test and subsequent determination of serotonin and dopamine metabolisms in mice housed in groups or isolated for 6 weeks. A resident/intruder test was performed with anpirtoline (5-HT1B receptor agonist in rodents; 1 mg/kg), citalopram (SSRI; 0.5 mg/kg) and saline treatment before animals were decapitated and different brain regions were frozen for subsequent HPLC-analyses. Behavioral investigations indicated a strong increase of aggressive behavior after 6 weeks of isolation housing. Acute citalopram treatment did not influence behavioral parameters of isolated and group housed mice. In contrast, anpirtoline antagonized isolation induced aggressive behavioral components in a specific manner. Analysis of dopamine and serotonin metabolism revealed that citalopram treatment did not affect dopamine metabolism, but reduced serotonin metabolism in the striatum, hippocampus, cortex and midbrain independent of housing conditions. In contrast, anpirtoline treatment increased dopamine metabolism in cortex, striatum and midbrain as well as influenced serotonin metabolism in a structure- and state-specific manner. Whereas anpirtoline decreased serotonin metabolism in the cortex, the midbrain and the hippocampus independent of housing conditions, in the striatum anpirtoline abolished the isolation induced decrease of serotonin metabolism. These results indicate that anpirtoline might induce antiaggressive effects via postsynaptic receptor- and structure-specific activation of serotonergic but also dopaminergic processes, whereas structure independent increase of synaptic serotonin via citalopram was ineffective to reverse aggressivity in isolated mice.

Aggression↗

PubMed2000

Open field locomotion and neurotransmission in mice evaluated by principal component factor analysis-effects of housing condition, individual activity disposition and psychotropic drugs.

Effects of housing condition and individual disposition on dopaminergically and GABAergically influenced open field locomotion and neurochemistry were studied in mice. Mice characterized as high active (HAM) and low active (LAM) by a running-wheel test were housed in groups or isolated for 1 day, 1 week, 3, 6, 12 or 18 weeks before an open field test was performed with saline, apomorphine (0.75 mg/kg) or diazepam (1.00 mg/kg) administration. Immediately afterwards animals were decapitated and brain sections were frozen for subsequent HPLC-analysis of dopaminergic and serotonergic transmitter metabolism. Principal component factor analysis (PCA) of locomotion variables provided three factors explaining 78.5% of total variance. Variables related to the amount of locomotion loaded highly on Factor 1 (F1-Activity), variables related to place utilization loaded highly on Factor 2 (F2-Exploration) and variables related to immobility and place preference loaded highly on Factor 3 (F3-Irritation). Apomorphine decreased F1-Activity with smaller effects in HAM and without changes in F2-Exploration and F3-Irritation independent on housing conditions. Diazepam exerted a decrease in F2-Exploration with a small increase in FI-Activity and no effects in F3-Irritation. Diazepam induced changes depended on housing conditions and were especially pronounced in isolated HAM. PCA of considerable locomotion and neurochemical data revealed interrelationships between striatal dopamine metabolism and F1-Activity, between cortical dopamine and serotonin metabolism and F2-Exploration as well as between cerebellar, hippocampal and striatal serotonin metabolism and F3-Irritation. The authors concluded that the application of PCA is a useful method to provide functionally relevant characteristics of behaviors and functionally relevant descriptions of interrrelationships between behavior and appropriate central nervous mechanisms. Furthermore the received behavioral characteristics (F1, F2, F3) of open field locomotion were sensitive to reveal housing and drug effects.

Animals↗

PubMed1998

Dynamic alterations of serotonergic metabolism and receptors during social isolation of low- and high-active mice.

Alterations induced by social isolation (1 day to 18 weeks) in low- and high-active mice (LAM and HAM) were studied in respect to serotonin metabolism, [3H]-8-OH-DPAT binding of presynaptic (midbrain), postsynaptic (hippocampus) 5-HT1A receptors and [3H]-ketanserin binding of cortical 5-HT2A receptors. Individual housing of mice was associated with reduction of serotonin metabolism, depending on isolation time and brain structure. Whereas a transient decrease in the striatum and cortex was detected between 1 week and 6 weeks, reduction of cerebellar and hippocampal serotonin metabolism was found later (12-18 weeks). Serotonergic systems of HAM were found to be more reactive to environmental disturbances, and their serotonin metabolism was more affected by social isolation. Isolation-induced upregulation of cortical 5-HT2A receptors was measured only in HAM. Densities of postsynaptic 5-HT1A receptors in the hippocampus did differ either in grouped or isolated mice. However, there were significant differences in hippocampal 5-HT1A receptor affinity, especially between 1 day and 3 weeks. Transient downregulation of presynaptic 5-HT1A receptors in the midbrain was found in isolated mice between 3 and 6 weeks. These results are discussed in terms of interactions between serotonergic alterations and isolation-induced aggression.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1998

Dopaminergic parameters during social isolation in low- and high-active mice.

Alterations induced by social isolation (1 day to 18 weeks) in low- and high-active mice (LAM and HAM) were studied in respect to locomotor activity, [3H]-spiperone binding in the striatum, striatal, and cortical dopamine metabolism, and presynaptic dopaminergic sensitivity to apomorphine (0.75 mg/kg; i.p.). Isolated HAM and LAM showed increased locomotor activity compared to group-housed mice after long-term isolation (6-18 weeks). Considering the studied dopaminergic parameters, it has been found that social isolation did not affect striatal D2 receptors, striatal and cortical dopamine metabolism, and apomorphine-mediated reduction of dopaminergic metabolism. The change of housing conditions was generally associated with an increase of cortical dopamine metabolism after 1 week. Activity type specific differences in group-housed LAM and HAM were found in the basal striatal dopamine metabolism and in the sensitivity of the nigrostriatal system to autoreceptor activation. The reduced striatal dopamine metabolism and the higher presynaptic sensitivity of HAM may be related to their high active running wheel behavior.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1998

Differences in whole blood serotonin levels based on a typology of parasuicide.

Suicidal behavior has to be considered as a multifactorial phenomenon, which can be analyzed in a classifying-phenomenological manner. We have examined the relation of parasuicide typology to whole blood concentrations of serotonin, HVA, and tryptophan in 58 patients classified into 4 groups of parasuicide typology compared to 22 nonsuicidal depressed patients and 20 healthy subjects. Suicidal patients classified as impetuous, desperate and ambivalent types had significantly reduced whole blood 5-HT levels in comparison with the appealing type as well as nonsuicidal subjects. No differences were detected in the HVA content, but whole blood tryptophan concentrations were significantly reduced in impetuous suicidal patients and depressed patients compared to healthy subjects. This study provides evidence for reduced whole blood serotonin content based on different types of parasuicide.

Adult↗

PubMed1995

Influences of housing conditions and ethanol intake on binding characteristics of D2, 5-HT1A, and benzodiazepine receptors of rats.

The effects of different housing conditions and ethanol treatment (6 vol % in the drinking water) on the in vitro binding characteristics of striatal dopaminergic D2 ([3H]spiperone), hippocampal serotonergic 5-HT1A ([3H]8-OH-DPAT), and cortical benzodiazepine ([3H]flunitrazepam) receptors have been examined. Social deprivation due to contact caging, short- (1 day) and long-term isolation (5 weeks) yielded a significant decrease of striatal D2 receptor density with the greatest decrease after long-term isolation (-21% Bmax) without changes of Kd in comparison to group animals. The effect of ethanol on striatal D2 receptor density depended on the housing conditions. Whereas ethanol treatment reduced receptor density of group animals (down to 88%), chronic exposure to ethanol under long-term isolation elicited no significant alteration of D2 receptor density compared with group animals. Different housing and ethanol treatment had no effect on 5-HT1A receptor affinity and density. Alterations of benzodiazepine receptor density were not found, but social deprivation as well as ethanol treatment of group animals caused an increased affinity of [3H]flunitrazepam (reduced Kd value). These results indicate that different housing conditions of adult rats evoked significant alterations in D2 and benzodiazepine receptor binding assays, which were modified by ethanol treatment in the case of striatal D2 receptor density.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1995

Music therapy following suctioning: four case studies.

This descriptive study evaluates and compares the effectiveness of music, presented both aurally and vibrotactilely, in reducing agitation and physiological instability following a stress-producing intervention (suctioning) in infants with bronchopulmonary dysplasia. Heart rate, oxygen saturation levels, level of arousal, stressful facial expressions, and autonomic indicators were recorded for each of four preterm infants. All infants experienced a reduction in the level of arousal during the taped music intervention when compared with the control condition. Three infants spent an increased amount of time in a quiet alert state and had improved oxygen saturation levels during the vibrotactile intervention. All infants spent more time sleeping during the taped music condition than without music or with the vibrotactile intervention. Results suggest that music is effective in reducing stress-related behaviors for some infants.

Arousal↗

PubMed1994

Individual motor activity--relationships to dopaminergic responses.

Owing to motor activity mice were divided into two groups in a running-wheel test: low-active mice (LAM) and high-active mice (HAM). Locomotor activities in the running wheel and in glass boxes are compared. The HAM showed a more intensive explorative behavior than LAM and were also more responsive in terms of exogenous factors than LAM. In contrast, LAM showed higher locomotor activity than HAM after habituation. Analyzing the response of LAM and HAM to dopaminergic agonists such as apomorphine, bromocriptine, and amphetamine, the role of specific dopaminergic mechanisms for the two types is discussed. Although apomorphine mainly stimulated the climbing activity in HAM, bromocriptine (climbing activity) and amphetamine (locomotion) had stronger effects in LAM. Differences may be assumed between LAM and HAM concerning the nigrostriatal and/or mesolimbic dopaminergic mechanisms. On the one hand, climbing activity following apomorphine application accompanied by stereotypes may suggest a stronger activation of striatal dopaminergic mechanisms in HAM. On the other hand, climbing activity following bromocriptine accompanied by jumping behavior, as well as the stimulation of locomotion after amphetamine, suggests a more effective activation of mesolimbic dopaminergic structures in LAM.

Amphetamine↗

PubMed1994

Influence of nootropic and antidepressive drugs on open field and running wheel behavior in spontaneously high and low active mice.

Mice differentiated by their running wheel activity into low and high active animals were chronically treated with the nootropics meclophenoxate, piracetam, vinpocetine, methylglucaminorotate, and the antidepressants lithium, desipramine, amitriptyline, and clomipramine. The influence of chronic drug treatment on running-wheel activity and open field locomotor behaviour was analyzed. Whereas with antidepressants rather sedative effects were observed in both activity types, the effects of nootropics were different in high and low active mice. Running-wheel scores increased in low active mice but decreased in high-active animals with an improvement in efficiency of locomotor behaviour in the open field of these mice after chronic nootropic treatment. In general, the effects of antidepressants seemed to be more uniform than those of the nootropics used.

Animals↗

PubMed1990

Effect of 2-mercapto-ethanol on some brain biochemical characteristics and behavioural changes in the ageing CBA/Ca mice.

Male CBA/Ca inbred mice were treated with a dose of 8 micrograms 2-mercapto-ethanol per animal per day in the drinking water from the age of 5 months onwards up to the age of 24 months. Dopamine release was greatly decreased in old animals in contrast to the elevation of dopamine release in the treated mice. Similarly, an elevated malondialdehyde content in brain homogenates was also observed in the aged treated animals compared with their controls. No essential differences were observed in locomotor activity and learning between treated an control mice.

Aging↗

PubMed1990

Effect of 2-mercaptoethanol on posthypoxic and age-related biochemical and behavioural changes in mice and rats.

2-Mercaptoethanol (2-ME) has a beneficial effect on the mean life span of laboratory rodents. This paper deals with the effects of 2-ME on changes of dopamine release from brain slices of old aged or hypoxia exposed mice and rats. The results were compared with data which reflect spontaneous peroxidation of brain lipid constituents. In addition, adequate behavioural properties were studied. Long-term 2-ME treatment for months abolishes the age-related decrease of transmitter release and prevents changes in malondialdehyde formation. If age-dependent release failure is already established, then neither single high doses of 2-ME nor repeated treatment for 3 weeks are effective. Posthypoxic release inhibition is prevented by a 2-ME pretreatment for 3 weeks but not by an acute single application even at high dosages. The preventive effect of 2-ME is a mediated one rather than an immediate direct action. Age-related behavioural deficits, such as locomotor activity, habituation performance and learning ability, do not reflect any effect of 2-ME long-term treatment.

Aging↗

PubMed1987

Neuronal transmitter sensitivity after social isolation in rats.

After 3 and 12 months of isolation rearing of rats, sensitivity of single neurons to microiontophoretically applied transmitters as well as neuronal spontaneous activity are analysed in striatum, cortex, hippocampus, locus coeruleus and nucleus raphis medialis. It is demonstrated that regulation of transmitter sensitivity, as well as spontaneous activity, depend on isolation duration, therefore showing time dynamics. Sensitivity changes of single neurons to distinct transmitters are not uniform and simultaneous in all areas but are structure specific. After 3 months of isolation an enhanced dopamine sensitivity is observed only in the striatum, whereas in the cortex the dopamine sensitivity is increased after 12 months isolation. A diminished response of single neuron activity to serotonin is demonstrable after 3 months of isolation in striatum and nucleus raphis. The observed changes are discussed in connection with biochemically and pharmacologically demonstrated changes in isolation. The complex patterns of neurobiological changes characterizing the isolation syndrome are emphasized.

Animals↗