Biomedical subjects

F Schober

Publications and source records attributed to F Schober.

At least 19 recordsLinked to original sources

PubMed2004

Bcl-2 expression inversely correlates with tumour cell differentiation in medulloblastoma.

Medulloblastoma (MB) is a cerebellar primitive neuroectodermal tumour that occurs predominantly in childhood. It can be mainly divided into classical and desmoplastic tumours, but differential diagnosis is often difficult. Patients' prognosis is poor and neuropathological markers that reliably predict outcome are still missing. In a series of 104 MBs including 80 tumours of the classical and 24 tumours of the desmoplastic variant we studied the number of apoptotic figures and the expression of the proto-oncogene bcl-2, an anti-apoptotic protein known to affect tumour cell proliferation. We observed a strong correlation between the expression of bcl-2 with patients' age (P < 0.001) as well as with the desmoplastic subtype (P < 0.001). Here, protein expression was found to be restricted to internodular, less differentiated, highly proliferative areas. In classical MB, bcl-2 was detected only in 23% of cases and was highly inversely correlated with the expression of synaptophysin (P < 0.001) indicating that bcl-2 is predominantly expressed by undifferentiated classical MB. With regard to prognosis the expression of bcl-2 tended to correlate with poor outcome in classical MB but not in desmoplastic MB, although not to a statistically significant extension (P = 0.06). On the other hand, a high number of apoptotic figures in the tumour tissue was found to indicate poor prognosis independent of the histological subtype (P < 0.05).

Adolescent↗

PubMed2003

[The value of the Kapandji-Sauvé procedure with considering clinical results and measurement of bone density. A clinical study].

Between 1989 and 1995, 33 patients were treated with a Kapandji-Sauvé procedure for malunited fracture of the distal radius and instabilities of the distal radioulnar joint. Thirty patients were followed up with a mean follow-up time of 91 months. Fourteen patients underwent a measurement of bone density of the distal forearm. Twenty-eight patients showed good ossification of the distal radioulnar arthrodesis. Forearm rotation improved by 17.3 %. Mean grip strength was 72 % of that of the contralateral hand. Evaluation by the Cooney score resulted in 10 % very good, in 65 % good, 22 % fair and in 3 % poor results. The measurement of bone density of the distal radius showed an increase of rotation and flexure firmness. The cortical density remained constant. In the subcortical bone of the distal radius, we found a decrease of the trabecular density in the radial part.

Adult↗

PubMed2003

[The hemiresection-interposition arthroplasty as a salvage procedure for the arthrotically destroyed distal radioulnar joint].

The arthrotically destroyed distal radioulnar joint will lead to painful limitation of forearm rotation. Alternative treatment options are the hemiresection-interposition arthroplasty or the Kapandji-Sauvé procedure. The aim of our study was to evaluate the clinical and functional results following the hemiresection-interposition arthroplasty in non-rheumatoid patients. The most common posttraumatic cause of the arthrosis was the malunited distal radius fracture. In a retrospective study we examined 36 of 51 patients with a mean age of 53 years after an average follow up of 34 months clinically, radiologically and using the DASH questionnaire. The average preoperative pain measured 7.8 on the visual analog scale and was reduced statistically highly significant (p < 0.01) to 3.9. Whilst pronation increased statistically not significantly from a mean of 74 degrees to 76 degrees (p = 0.428), supination improved significantly from 54 degrees to 69 degrees (p - 0.012). The average grip strength increased statistically highly significant (p<0.001) from 40% to 64% compared to the unaffected side. Patients' satisfaction with the result averaged 6.9 on a visual analog scale. Using a modified Mayo-wrist score, six patients were rated to have an excellent, eleven patients a good, ten patients a satisfactory and four patients a poor result. The average DASH score measured 35. In 21 patients radioulnar impingement was found. This appeared to be painful in 14 patients and required revision surgery using the ulnar head prosthesis in five patients. In three patients, secondary ulnar shortening had to be performed due to a remaining painful impaction of the distal ulna against the lunate and triquetrum. Comparing our clinical results with the reported results following the Kapandji-Sauvé procedure from the literature, there was no evident superiority of either of the procedures. There is a need for a functional evaluation following the Kapandji-Sauvé procedure to compare the remaining functional impairment following both procedures. In conclusion both procedures have to be classified salvage procedures and therefore the indication should be limited to the arthrotically destroyed distal radioulnar joint.

Adult↗

PubMed2001

Description of healthy and disturbed sleep by means of the spectral frequency index (SFx) - a retrospective analysis.

OBJECTIVES: Aim of the study was to describe the sleep of patients with sleep disorders by means of the spectral frequency index (SFx) in comparison to healthy subjects. METHODS: Polysomnographic data of two consecutive nights recorded in healthy subjects (n = 18), patients with insomnia (n = 19), snoring (n = 29) and obstructive sleep apnoea (n = 28) were analysed retrospectively by using an automatic sleep staging system and the EEG-derived SFx. The SFx data were related to the factor values of the sleep questionnaire SF-A. RESULTS: It was possible to describe the sleep intensity and stability and to document clear differences between healthy and disturbed sleep by means of the SFx. For all included subjects the time spent in middle deep sleep (SFx-range Z(D)) seemed to be of great importance for the subjective assessment (SF-A) of "sleep quality". A great variability within the range of light sleep was related to a negative assessment of "sleep quality" and "feeling of recovery after sleep", while greater "psychic balance in the evening" before sleep was related to a reduced variability in the range of light sleep. A sleep quality index derived from the SFx-values is described which correlates with the subjective estimation of disturbed sleep in insomnia and apnoea patients. CONCLUSIONS: The main advantage of this method in comparison to the visual sleep scoring system is that the depth of sleep is assessed objectively and described continuously.

Adult↗

PubMed1999

[Bowers hemi-resection-interposition arthroplasty for treatment of post-traumatic arthrosis of the distal radio-ulnar joint after distal radius fractures].

UNLABELLED: Arthrosis of the distal radioulnar joint (DRUJ) is a common problem following fractures of the distal radius. The treatment options include the hemiresection-interposition technique (Bowers procedure) or Kapandji-Sauvé procedure. In a retrospective study, we assessed the results of the Bowers procedure. MATERIAL AND METHODS: From 1992 to 1997, 24 patients were treated by the hemiresection-interposition technique (Bowers procedure) for arthrosis of the DRUJ following fracture of the distal radius. The average follow-up time was 30.5 (9 to 55) months. RESULTS: The average preoperative pronation was 67 degrees, the supination 45 degrees. Postoperatively, we found a pronation of 80 degrees and a supination of 62 degrees. Grip-strength compared to the opposite site could be improved from 38 to 57% postoperatively. Pain was reduced markedly in 78% of the patients. However, ten patients developed a postoperative instability of the distal ulna. In only two patients did painful instability necessitate revision procedures. CONCLUSION: The hemiresection-interposition technique is a salvage procedure for the destroyed DRUJ, leading to good clinical results in most patients. Painful instability of the distal ulna and remaining functional deficits can be the reasons for failure. Therefore, adequate primary reduction of fractures of the distal radius or secondary reconstruction of the anatomy is necessary to prevent secondary arthrosis of the DRUJ.

Adult↗

PubMed1998

Validation of an EEG-derived spectral frequency index (SFx) for continuous monitoring of sleep depth in humans.

Sleep in humans is classically assessed by recording a multichannel electroencephalogram (EEG) in connection with an electrooculogram (EOG) and an electromyogram (EMG). In general, human sleep is manually staged into 6 categories (from awake through REM sleep to stage 4 reflecting deep sleep) on the basis of a visual inspection of EEG periods (epochs) of 20 - 30 s duration. This cumbersome methodology is still used in practice and for reference purposes. - The conversion of EEG-signals by means of Fast Fourier Transformation provides objective and reproducible information reflecting specific communicative features of the central nervous system. A special part of this information based on a specific algorithm is defined by the so-called spectral frequency index (SFx). This SFx-algorithm contains relationships among some particular EEG frequencies and provides objective percentage values about the state of consciousness of a person. In order to validate this new SFx-method, sleep as a physiological state of continuous alterations of consciousness and vigilance was chosen. A total of 36 nights of sleep from 18 healthy volunteers were staged manually by a scientist unaware of the protocol. The volunteers received either placebo or lormetazepam prior to commencement of the nocturnal recordings. The manually staged data were compared with the data obtained by the SFx-analysis. Both data sets SFx values and manually staged data were made comparable by averaging their values to a basic period length of 2 min duration giving 7960 pairs of data. The SFx data for sleep were found within a range from 35% to 100%. The SFx-medians of the manually staged data from "awake" to stage 4 were found in a decending order ("awake": 83% (lower and upper quartile 78% / 87%);"REM": 68% (63%/74%),"stage 1" :63% (57%/70%),"stage 2" :51% (47%/57%), "stage 3" :44% (42%/46%) and "stage 4" :42% (40%/44%). The rank correlation coefficient between the data pairs was calculated to be 0.79 indicating a substantial matching between the manually staged score and the SFx. We therefore conclude that the SFx is a suitable and objective indicator of sleep depth in humans.

Adult↗

PubMed1998

Effects of a methanolic extract and a hyperforin-enriched CO2 extract of St. John's Wort (Hypericum perforatum) on intracerebral field potentials in the freely moving rat (Tele-Stereo-EEG).

Two extracts of St. John's Wort (Hypericum perforatum) were investigated in the animal model "Tele-Stereo-EEG" which consisted of continuous recording of intracerebral field potentials in the freely moving rat. One was a CO2 extract for research purposes containing 30.14% hyperforin, a phloroglucine derivative known to occur within the reproductive parts of the plant, and lacking other major constituents like naphtodianthrones and flavonoids according to HPLC fingerprint. The other extract was the methanolic extract LI 160S (4.67% hyperforin). The dosage schedule was elaborated for the application of identical amounts of hyperforin in both extracts in each dosing group. Both extracts produced nearly identical patterns of electrical power changes during the first two hours of recording. These changes mainly consisted of reproducible power increases within the alpha1 band of the striatum. Comparison with earlier data obtained by identical protocols revealed that the early action was very similar to that following the application of serotonin reuptake inhibitors, thus matching biochemical in vitro data previously reported. These changes might be due to the presence of hyperforin. Only LI 160S developed a late action not seen with the CO2 extract, consisting in increases in delta activity. This late action of LI 160S matched data obtained by analysis of the action of NMDA-antagonists like MK 801 or memantine. Again, these results support previously reported biochemical findings of the interaction of hypericum extract with the glutamatergic system. In all probability, this action stems from substances only present in LI 160S, not in the CO2 extract. Which of the components contained within hypericum extracts are responsible for the clinical efficacy of St. John's wort in depression remains to be determined.

Animals↗

PubMed1998

[Ulna impaction syndrome therapy: decompressive surgical procedures of the head of the ulna].

The ulnar impaction syndrome can be defined as the impaction of the ulnar head against the triangular fibrocartilage complex and ulnar carpus. As a result of this pattern, painful degeneration of the TFCC occurs. Wrist arthroscopy offers a certain diagnostic tool. In addition, arthroscopic debridement of the TFCC shows a high success rate of 70 to 80 percent. After failed arthroscopic debridement, ulnar shortening osteotomy reduces ulnar load significantly. Malunion of the radius resulting in posttraumatic ulna-plus variance should be treated by correction osteotomy with lengthening of the radius. If arthrosis of the distal radioulnar joint is combined with ulnar impaction syndrome, the hemiresection procedure of Bowers or the method of Kapandji-Sauvé are the methods of choice.

Arthroscopy↗

PubMed1997

Pathophysiology and psychopharmacology of dementia--a new study design. 2. Cyclandelate treatment--a placebo-controlled double-blind clinical trial.

The aim of this randomized, double-blind, placebo-controlled 16-week study was to investigate the clinical efficacy of cyclandelate (Natil, 1,600 mg/day) in 139 adult outpatients with cognitive impairment (70 allocated to cyclandelate; 69 to placebo). Quantitative-topological EEG, event-related potentials (P300) and psychophysiological interview-based rating scales were used. The efficacy of cyclandelate was demonstrated in the confirmatory statistical sense using a global Hailperin-Rüger test on 10 predefined primary variables at global significance level of 0.05 relating to psychopathology, psychometry, neuropsychophysiology and behavior. At psychopathological and behavioral level the reduction of the total scores of the rating scales (Alzheimer Disease Assessment Scale, Sandoz Clinical Assessment Geriatric Scale, and Nürnberger Selbsteinschätzungs-Liste) following a 16-week therapy revealed also an individual significant cyclandelate-placebo distinction in the confirmatory statistical sense. A difference between verum and placebo was also observed by the increase of the number of correct answers during performance of the number symbol test (psychometrical level). The objective electrophysiological data (neuropsychophysiological level) support these findings. Of particular interest is that following cyclandelate treatment the absolute theta power remained almost unchanged and an increase of P300 amplitude was observed. At the same time placebo led to a distinct theta power increase and a decrease of P300 amplitude, which was interpreted as the reflection of an impairment of the initial clinical state. Summarizing, cyclandelate proved to be efficacious compared to placebo in patients with mild to moderate cognitive impairment.

Aged↗

PubMed1996

Source density analysis of functional topographical EEG: monitoring of cognitive drug action.

Electrical changes of the brain induced by mental work in the presence or absence of a drug formulation containing dimethylaminoethanolorotrate (DMAE), vitamins and minerals were analysed. Sixty elderly volunteers (30 females and 30 males; aged 40 - 65) who lacked concentration and efficiency during mental exercise according to their own opinions participated in a double-blind, placebo-controlled study. The EEG recordings were carried out before and after 12 weeks medication and were analysed according to the electrical charges at the scalp surface (Laplacian estimate) followed by Fast Fourier Transformation to obtain quantitative data. Whereas no change of electrical charge could be observed after 12 weeks of treatment in the placebo group, the verum group taking 1 capsule per day of an established drug containing a biogenic amine-vitamin combination revealed decreases in theta power during rest and increases in absolute theta power induced by mental demand within the area known to change its electrical activity during mental exercise. In the light of the current hypothesis that high theta resting power and low increases at frontotemporal brain areas during mental work indicate mental impairment, treatment with the drug under investigation was seen to successfully reverse these changes. This drug effect was localized in the frontotemporal cortex in a statistically significant manner during both the memory and the symbol recognition tests. The observed effect is fully consistent with a previous study using Fourier transformed data from conventional EEG voltage recordings. It can be concluded that an analysis of EEG data by means of the charge mode provides an excellent tool to quantify drug effects especially in cognitive research. A second perspective arises from the fact that it should be possible to recognize mental impairments at a very early stage by using this method, thus providing the possibility of an early treatment.

Adult↗

PubMed1996

Electroencephalogram activity, catecholamines, and lymphocyte subpopulations after resistance exercise and during regeneration.

We examined the effect in ten male sports students of 30-min resistance exercise followed by either 45-min regeneration with massage treatment on a massage bench or supine rest serving as control, on plasma catecholamine concentration, number and distribution of circulating white blood cells and central activity. Resistance exercise increased free plasma adrenaline (A) and noradrenaline (NA), whereas sulphoconjugated catecholamine concentration remained unchanged as determined by high performance liquid chromatography. Exercise induced leucocytosis and lymphocytosis measured by flow cytometry was predominantly manifested by an increase in the number of lymphocytes, monocytes, CD3+ cells, CD8+ cells and CD3- CD16/56+ cells. Computer-aided electroencephalography (EEG) revealed significant increases in absolute EEG band power. The increase was highest in alpha 2 with 51.6 (SD 40.2)% (P < 0.01), followed by beta 1 with 33.3 (SD 21.0)% (P < 0.01), alpha 1 with 31.9 (SD 25.2)% (P < 0.01), beta 2 with 30.8 (SD 26.7)% (P < 0.01), delta with 26.1 (SD 28.7)% (P < 0.05), and theta with 19.8 (SD 16.5)% (P < 0.01). All hormone and immunological variables returned to pre-exercise values 45 min after exercise with no differences between massage and control treatments. However, during regeneration differences in absolute EEG-band power were observed between massage and control treatments. In central (Cz, C3, C4) and fronto-lateral (F3, F4) electrode positions absolute beta 1 spectral power density was significantly lower during massage treatment than during control (Wilcoxon test: P < 0.01). Overall, these data demonstrated that an influence of massage treatment on deactivation characteristics could be observed in EEG measurements but not in plasma catecholamine concentration or blood lymphocytes, indicating that computer-aided topographical EEG may be a useful technique for studying activation and regeneration characteristics.

Adult↗

PubMed1995

The influence of electromagnetic fields on human brain activity.

Possible effects of electromagnetic fields on human brain activity were studied. In a single-blind, cross-over-designed and placebo-controlled study 36 volunteers were exposed firstly to an electromagnetic field originating form a MediLine "MEGA-WAVE 150/1" therapy instrument and secondly to a field originating from a mobile, digital tetlephone as used for wireless telecommunication. All volunteers also underwent a control experiment with no field exposure. Application of the MEGA-WAVE instrument caused an increase in EEG power in the frequency bands Alpha2, Beta1 and Beta2 during and after field exposure. Operation of the mobile telephone caused an increase in the same frequency bands with a delay of approximately 15 minutes after exposure.

Brain↗

PubMed1995

Reflection of mental exercise in the dynamic quantitative topographical EEG.

The aim of this study was to investigate the activation process of the central nervous system during mental demand in a complex psychophysiological situation. A 17-channel quantitative topographical EEG was recorded in 48 healthy volunteers (male and female, aged 49 +/- 6 years), using the CATEEM system, during four different psychometric tests (simple reaction time measurement, concentration performance, figure detection and word recall test). The mental load varied with each test, producing a graduated increase in spectral power density in delta and theta frequency range on the EEG in the fronto-temporal, parietal and occipital regions of the cortex and a generalized decrease in alpha power. During the rest periods after each test a graduated increase in alpha 1 power was seen as a possible expression of change in vigilance level. With this method we were able to differentiate two effects of psychometric tests on brain activity: the actual mental demand itself and the influence on the vigilance level.

Adult↗

PubMed1995

Pathophysiology and psychopharmacology of dementia--a new study design. I. Diagnosis comprising subjective and objective criteria.

In a double-blind placebo-controlled psychopharmacological study 263 patients with cognitive impairment were screened and 137 of them were selected (following defined inclusion and exclusion criteria) to participate in a clinical trial (for results of treatment phase see part II, in preparation). The pretreatment state was evaluated twice using quantitative-topological EEG (qEEG) and psychopathological rating scales. There is a significant correlation between total score values of nearly all dementia-specific neuropsychological rating scales and absolute spectral power in the lower frequency ranges (delta, theta, alpha 1) at rest. In order to increase the diagnostic power, qEEG was recorded simultaneously with the performance in four different psychometric tests. It was found that the worse the psychopathological rating of a patient, the higher the absolute theta power at rest and the smaller the test- and demand-dependent further increase in theta power. The percentage of task-induced power increase in delta and theta frequency range appeared to be an efficient indicator for a reliable discrimination between healthy elderly individuals and demented patients (rank correlation coefficient for theta in F7: r = +0.55), which will also serve for evaluation of treatment.

Aged↗

PubMed1994

Quantitative EEG and BPRS data following Haldol-Decanoate administration in schizophrenics.

Approximately one-third of schizophrenic patients receiving antipsychotic drugs obtain little or no benefit from them. In some reports, response has been linked with "prognostic" factors, including abnormal EEG and drug response (pharmaco-EEG). Measurements of topological EEG spectral power and Brief Psychiatric Rating Scale (BPRS) values were obtained in 15 schizophrenics over a period of 20 min immediately after the first application, and at weekly intervals after single intramuscular injection of 2 ml depot haloperidol (Haldol-Decanoate). A highly significant increase in the alpha-1 power density at almost all positions and an increase in theta power at parietotemporal regions can be described as electrophysiological parameters of the acute pharmaco-EEG. BPRS values decreased continuously within the first 2 weeks followed by an increase to the predrug level after the fourth week. Over the whole observation period there was a correlation between neurophysiological data (alpha-1 power) and clinical symptomatology (BPRS total score; r = -0.7). Therefore, it can be concluded that quantitative EEG recordings are able to serve as a tool for the optimization of the depot neuroleptic treatment in schizophrenics.

Adult↗

PubMed1994

[A new method for assessment of mental performance during simultaneous, quantitative, topographical electroencephalometry and psychometry in pharmacology. Proof of the effect of a combination of biogenic amines, vitamins, minerals and trace elements].

Assessment of the Mental Performance during Simultaneous Quantitative Topographical Electroencephalometry and Psychometry in Pharmacology/Proof of influence of a biogenic amine-vitamin combination. The aim of this study was to verify the effect of a combination medicine (Vita-Gerin-Geistlich) on the human EEG pattern during psychometric (cognitive) tests given to 43 patients with poor concentration and thinking problems. A randomised, parallel, placebo-controlled double-blind study was performed. Applying 17-channel quantitative electroencephalometry and psychometric tests simultaneously this study revealed a test-dependent increase in absolute spectral EEG power in the delta and theta frequency bands, mainly observed in the frontotemporal cortex. After 8 weeks the increase in EEG power differed significantly with respect to taking placebo and verum (1 capsule/day). Verum caused a stronger rise in spectral delta and theta power, the psychometric test performance also improved. Both effects could be verified statistically. The novel EEG-controlled psychometric test set (enabling artefact-free EEG recording during psychometric tests) which was developed and used in this study represents a valid tool for future pharmacological research.

Adult↗

PubMed1994

[Evidence of a pharmacokinetic-pharmacodynamic relationship between pharmaco-EEG in healthy subjects after administration of cyclandelate].

In an open randomized cross-over study 800 mg cyclandelate (Natil, CAS 456-59-7) was applicated to 24 young, male volunteers. Before and during 24 h after application of a single dose a 17-channel, quantitative topographical pharmaco-EEG was recorded. A significant increase of the spectral power density was observed in the alpha 2, beta 1 and beta 2 frequency bands starting 2 h after application until 4.5 h. The increase in beta 1 and beta 2 power was observed in the parietocentral area of the cortex. The difference between the circadian development of the EEG power and the development after medication was obvious after 3 until 4.5 h. For the beta frequencies only a weak statistical confirmation could be obtained, but for the alpha 2 frequency a significant difference between the circadian and the EEG power under cyclandelate was found using the sign test. Altogether a quantitative effect on brain activity was detected after oral application of cyclandelate, reaching its maximum before the blood concentration of the metabolites cyclandic glucuronide and mandelic acid reached their peak heights.

Adult↗

PubMed1993

The influence of caffeine on human EEG under resting conditions and during mental loads.

The effect of caffeine (single oral doses of 200 mg and 400 mg) on the CNS was tested under resting conditions and while performing a concentration performance test in a placebo-controlled pilot study on ten healthy males. The EEG was evaluated quantitatively by spectral analysis with a Computer Aided Topographical ElectroEncephaloMetry system. Comparison of the averaged frequency content revealed a clear difference between the change in the functional state of the brain due to the mental arithmetics, on the one hand, and the caffeine effect, on the other. Both states of altered brain activity were reflected in a particular topographical distribution of the frequency change with respect to a frontal-occipital accentuation. Comparison of the two periods of mental arithmetics in the absence or presence of caffeine showed a tendency to concentration-dependent differences from each other. Administration of 200 mg and 400 mg caffeine in the relaxed state effected the decrease in spectral power in the theta and alpha ranges. The concentration performance test without caffeine effected decreases in power in the alpha range in frontal to parietal cortex and enhanced theta power in frontal and occipital regions and the alpha power in occipital cortex. The caffeine-dependent decrease in theta power and the decrease in delta power seen under relaxation conditions after 400 mg are not observed during the concentration performance test in the presence of caffeine.

Adult↗