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Biomedical subjects

H Ebel

Publications and source records attributed to H Ebel.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Hypnogogic hallucinations of macrosomatognosia and microsomatognosia].

Macrosomatognosia and microsomatognosia, in which the entire body or parts of the body are perceived as abnormally large or small, can occur as hypnagogic hallucinations in sane and healthy subjects. A review of the literature and five original observations are presented. The mouth and the hands are anatomic regions which are frequently affected, paralleling the dominance of their representation in the sensory maps of the human brain. The clinical differential diagnosis of the said phenomena includes narcolepsy, epileptic and migraine aura, drug-induced body schema disturbances and basic symptoms of functional psychoses.

Adult↗
PubMed1998

[Psychiatric contribution to the debate on films of the silent movie era in Germany].

Literary writers and scientists of various disciplines have contributed to debates about the silent movie in the 10s and 20s in Germany, leading to basic insights into the structure and effects of the new film medium. Psychiatric authors of the documented period have elaborated propositions towards a theory of film perception and analyses of different possibly nocuous film effects. The hypothesis of a causal effect of the film medium on violence and the notion of a transmission of suicidal behaviour by fictitious film models are still controversially discussed.

Art↗
PubMed1997

Factors predicting pituitary adenoma invasiveness in acromegalic patients.

Forty-four adult acromegalic patients carrying growth hormone-producing pituitary macroadenomas were investigated with neuroradiological and endocrinological techniques. Plasma growth hormone and somatomedin-C levels were repeatedly measured before surgical removal of tumors and during the follow-up period. Twenty-five patients presented preoperatively with an invasive adenoma that involved the cavernous sinus (CS). Diagnosis of tumor invasivity was made according to distinct neuroradiological criteria and was confirmed or rejected during surgery Significantly higher basal growth hormone levels were found in patients with CS invasion than in cases without tumor growth in the CS. Evidence is presented that plasma growth hormone level in acromegalics is a more sensitive indicator for predicting tumor invasiveness than somatomedin-C. Growth hormone basal values before surgery and the extent of their decrease after removal of tumor correlate with adenoma growth in the parasellar compartments and should be used as a prognostic factor to aid in planing adjuvant tumor treatment.

Acromegaly↗
PubMed1997

Pancreas-specific protein (PASP), serum amyloid A (SAA), and neopterin (NEOP) in the diagnosis of rejection after simultaneous pancreas and kidney transplantation.

A reliable, noninvasive indicator of pancreatic allograft rejection is urgently needed. In this study, serum (S), plasma (P), and urine (U) levels of pancreas-specific protein (P-PASP, U-PASP), neopterin (S-NEOP, U-NEOP), amylase (U-AMYL), and amyloid A (SAA) were measured daily in ten type I diabetic patients following simultaneous pancreas and kidney transplantation (SPK). Rejection episodes occurred in three isolated pancreas, nine isolated kidney, and five simultaneous pancreas and kidney transplants. In the case of the eight pancreas rejections, SAA was the rejection marker with the highest diagnostic accuracy (94%). Using P-PASP and U-PASP, an accuracy of 81% and 79%, respectively, was achieved. During viral infections, U-NEOP levels increased to a maximum level of 1904 mumol/mol creatinine, whereas during bacterial infections, SAA levels increased to a maximum value of 43 mg/dl. SAA, measured for the first time in SPK, appears to be a valuable rejection parameter. In combination with U-NEOP and U-AMYL, a differential diagnosis between rejection, bacterial infection, and viral infection was possible. Neither U-PASP nor P-PASP monitoring led to a significant improvement in the results.

Acute Disease↗
PubMed1997

Impact of profile haemodialysis on intra-/extracellular fluid shifts and the release of vasoactive hormones in elderly patients on regular dialysis treatment.

In 15 patients with end-stage renal failure and proven coronary heart disease, profile haemodialysis with decreasing ultrafiltration rate and hyperionic, decreasing dialysate solute concentration was compared with conventional, extracorporeal bicarbonate haemodialysis (Na+D = 138 mmol/l). Body fluid distribution and the release of vasoactive hormones (plasma renin activity, aldosterone, norepinephrine, epinephrine, and atrial natriuretic peptide) were investigated. Haemodialysis with constant ultrafiltration rate and constant dialysate composition (A) was followed by two dialysis profiles: decreasing ultrafiltration rate (B) and additional hyperionic, decreasing dialysate sodium concentration (C). In all 15 patients, the dialysis procedures (A) - (C) were used for 2 weeks each with six sessions, the last being taken for investigation. Body fluid distribution was calculated. In patients with serum sodium above 136 mmol/l, the conventional dialysis (A) as well as the Uf profile (B) showed a net fluid shift from extracellular volume (ECV) to intracellular volume (ICV). Using the profile with hyperionic, decreasing Na+D (C), the reverse fluid shift with decreasing ICV was achieved not only in those with serum Na+ <136 mmol/l, but also in those with serum Na+ > or = 136 mmol/l. The release of vasoactive hormones decreased already at profile haemodialysis (B) compared with (A) and was further reduced in (C). These results would suggest, profile dialyses B and C to have less impact on the cardiovascular system in elderly patients assuming higher patient comfort compared with the standard dialysis procedure. A higher benefit was obtained in C compared with B, presumably due to the additional prevention of the ICV shift and plasma volume depletion in patients with initial serum sodium > or = 136 mmol/l using transiently hyperionic Na+D. These results show that in elderly patients, hyperionic profile haemodialysis (Na+D > Na+S) had less impact on cardiovascular regulation than conventional bicarbonate dialysis.

Aged↗
PubMed1996

Chronic precentral stimulation in trigeminal neuropathic pain.

The results of Deep Brain Stimulation in deafferentation pain syndromes, in particular in thalamic pain, indicate that excellent long-term pain relief can hardly ever be achieved. We report 7 cases using Motor-Cortex-Stimulation for treating severe trigeminal neuropathic pain syndromes, i.e., dysaesthesia, anaesthesia dolorosa and postherpetic neuralgia. The first implantation of the stimulation device for precentral cerebral stimulation was performed in June 1993, the last in September 1995. In all but one case the impulse-generator was implanted after a successful period of test stimulation. Successful means a pain reduction of more than 50% as assessed with a Visual Analogue Scale. Excluding one case, in whom a prolonged focal seizure resulting in a postictal speech arrest occurred during test stimulation, there have been no operative complications and the postoperative course was uneventful. In all the other patients the pain inhibition appeared below the threshold for producing motor effects. Initially these patients reported a good to excellent pain relief. In three of 6 patients a good to excellent pain control was maintained for a follow-up period of 5 months to 2 years. In the remaining three patients the positive effect decreased over several months.

Adult↗
PubMed1996

Diagnostic validity of basic symptoms.

Although the Bonn Scale for the Assessment of Basic Symptoms (BSABS) [13] has come into use in several European countries, its diagnostic validity has not yet been sufficiently examined. That is why we have assessed BSABS items on a sample of 243 consecutive admissions to the Department of Psychiatry at the RWTH University, Aachen, and 79 psychologically healthy persons. Then, a cluster analysis was calculated to identify the empirical item-grouping. Five well-interpretable BSABS subsyndromes were found. In addition, uni- and multivariate analyses were computed to evaluate the diagnostic validity of these subsyndromes. We were able to show that every BSABS subsyndrome separates at least schizophrenic, organic mental and affective disorders from personality, neurotic and substance-induced disorders, as well as from psychological health. Furthermore, the subsyndrome "information processing disturbances" differentiates between schizophrenic and organic mental disorders, on the one hand, and affective disorders, on the other, and additionally, the subsyndrome "interpersonal irritation" between schizophrenics and all other persons examined.

Adult↗
PubMed1996

[Value of stereotaxy in neurosurgery. Indications and analysis of results of 71 cases].

CT- or MRI-guided stereotactic procedures should be a standard in a modern neurosurgical unit. Analysing 71 cases the indications and results of stereotactic neurosurgery are presented. In 53 patients stereotactic serial biopsies of different intraaxial lesions were performed, in 5 patients a spontaneous haemorrhage of the basal ganglia was removed by lysis with r-tPA. In 3 patients suffering from hydrocephalus due to diencephalic cysts a cystventricular shunt device was implanted. In 3 patients an intracerebral abscess was aspirated and drained. A stereotactic guided craniotomy and excision of small deep-seated lesions was performed in 6 cases. The accuracy of stereotactic tumour biopsies was 88.7% in our series, in accordance to other authors. The stereotactic aspiration and drainage of an intracerebral abscess provides accurate localization and minimal cortical damage and offers the possibility of intracavitary application of antibiotics. The stereotactic internal shunt implantation seems to be an alternative approach in the treatment of diencephalic cysts due to its minimal invasiveness and low operative risk. The aspiration of basal ganglia haematomas with insertion of an external drainage allows the lysis of the haematoma with r-tPA or urokinase. With stereotactic guidance small, deep-seated intraaxial lesions can be well localized and removed.

Aged↗
PubMed1996

Vasomotion, regional cerebral blood flow and intracranial pressure after induced subarachnoid haemorrhage in rats.

The objective of our study was to examine the relation of the intracranial pressure (ICP), cerebral perfusion pressure (CPP), regional cerebral blood flow (rCBF), and vasomotion in the acute phase in rats after having induced subarachnoid haemorrhage (SAH). The experiments were carried out on a total of 21 Wistar rats by means of neuroleptanalgesia and controlled mechanical ventilation. In 16 animals SAH was induced according to the method described by Solomon et al. with a fractionated application of 0.5 ml autologous blood into the cisterna magna. In a control group 0.5 ml of physiological saline solution was injected under identical conditions. The parameters were registered continuously before, during and at least 3 hours after the bolus application. The rCBF and vasomotion were recorded by laser-doppler fluxmetry. The ICP and the systemic arterial blood pressure were registered simultaneously. In the course of the experiment blood gas analyses were carried out regularly for documentary reasons of normoventilation. Our results show that the Cushing-response-after having induced SAH-led to a deterioration of the cerebral perfusion. In the control group however an increase in ICP and rCBF was recorded. The frequency and amplitude of the oscillations of Doppler signals, described as vasomotion, were significantly reduced in the SAH group as compared to the control group (p = 0.0004) during the course of the experiment. After having induced SAH an impairment of the cerebral autoregulation becomes apparent which seems to manifest itself on the level of microvascular structures as a suppressed behaviour pattern of vasomotion. Although basal vessels may constrict distal parenchymal vessels tend to dilate after SAH. The dilation-described as a reduction of vasomotion-could also be measured in clinical situations by means of laserdoppler fluxmetry.

Animals↗
PubMed1996

[Interdisciplinary concepts of surgical sex transformation in transsexual patients].

From the introduction of the law on recognition of transsexuals (TSG) in 1980, over 1400 decisions were made by German regional district judges up to 1990. In over 90% of the cases the desired gender was accepted and attested officially. In the near future, a growing number of requests has to be expected. Generally, transsexual patients desire surgery to achieve a complete sex change. Since the foundation of an interdisciplinary gender dysphoria identity committee at our institution in 1989, we have developed criteria on indications, operative techniques and follow-up, which would overtax a urology department, but which can be managed by an interdisciplinary team. Operative techniques may be regarded as well standardized in male-to-female transsexuals and may be performed by the urologist alone; in female-to-male transsexuals sex transformation remains complex interdisciplinary challenge to urologists and plastic surgeons, mainly due to urethral complications. Continuous psychiatric guidance and endocrinological monitoring of the patients facilitates indications for surgery and perioperative management.

Adult↗
PubMed1996

Effects of pipecuronium and pancuronium on cerebrospinal fluid pressure in neurosurgical patients.

Arterial hypertension and/or tachycardia may alter intracranial pressure in neurosurgical patients. We compared the effects of pancuronium 0.1 mg/kg and pipecuronium 0.1 mg/kg given as i.v. bolus on cerebrospinal fluid (CSF) pressure in 2 groups of 10 patients each scheduled for intracranial surgery in the supine position. Before surgery, no patient presented clinical symptoms of elevated intracranial pressure (ICP). Anesthesia was induced and maintained with fentanyl and midazolam. Ventilation with 50% nitrous oxide in oxygen was adjusted to maintain arterial pCO2 at 30-35 mmHg. After induction of anesthesia, CSF pressure was registered via a lumbar subarachnoid catheter before and 3, 5, 10, and 30 min after pipecuronium or pancuronium administration. Hemodynamics were monitored using radial and pulmonary artery catheters. All variables underwent analyses of variance for repeated measures with p < 0.05 considered significant. Mean CSF pressure decreased insignificantly from 15 +/- 5 mmHg (before injection) to 14 +/- 4 mmHg in patients given pipecuronium and from 13 +/- 4 mmHg to 10 +/- 3 mmHg in the pancuronium group without significant differences between the study groups. Heart rate and arterial pressure increased significantly (p < 0.001) in patients given pancuronium but remained stable after pipecuronium. Onset and duration of neuromuscular blockade were comparable between groups. Based on our results, pipecuronium is a safe alternative to pancuronium during neurosurgical procedures in patients without abnormally high intracranial pressure.

Adult↗
PubMed1995

Platelet aggregation inhibiting and anticoagulant effects of oligoamines, XXV: Interactions of the oligoamine RE 1492 with biomembranes.

The absorption of D-glucose by rat thymocytes is reduced to half of control by 30 mumol/L and decreased to 10% by 100 mumol/L of RE 1492. This is backed by the fact that the absorption of 2-deoxy-D-glucose is inhibited in the same extent. The more hydrophilic oligoamine RE 1888 had an analogous but smaller effect while spermine was ineffective. In a lipid peroxidation model RE 1492 or spermine in a concentration of 100 mumol/L nearly completely inhibited for formation of Fe3+ ions when the phospholipid was mimicked by adenosine monophosphate. This suggests an interaction with negatively charged membrane phospholipids. RE 1888 had an equal but smaller effect. The effect of RE 1492 on lipid order and lipid motility was checked on ovine lymphocyte membranes by fluorescence polarization measurements. The steady state as well as the limiting anisotropy as an expression for lipid order is decreased by rising concentrations of RE 1492. The use of several anthroyloxy stearic acids as fluorescent probes also shows an increased lipid motility in several areas of the membrane bilayer. The use of fluorescent parinaric acid suggests that areas of high regularity, i.e. liquid crystal formation are involved, too.

Animals↗
PubMed1995

Quantitative surface analysis by total electron yield.

When the surface of a solid sample is irradiated under vacuum by x-rays an electron emission, owing to photoabsorption, can be measured. As the electrons are detected under neglection of their kinetic energies the total electron yield (TEY) is determined. With a tuneable x-ray monochromator the TEY is measured below and above of one of the absorption edges of a given element. A jumplike increase of the TEY signal, due to the additional photoabsorptions in the corresponding atomic level, can be observed - qualitative analysis. The height of this jump can be correlateted to the concentration - quantitative analysis. It can be shown by a fundamental parameter approach for primary and secondary excitations how to use TEY for a quantitative analysis. The information depth lambda of this new method is approximately 2-400 nm depending on the chemical elements and on the original kinetic energies of Auger and photoelectrons. Thus, TEY is located between photoelectron spectrometry and x-ray fluorescence analysis.

Journal Article↗
PubMed1995

Depth profiling by ARXPS in surface analysis.

A method of nondestructive depth profiling in near surface regions of solids is described. Models have been discussed from which algorithms for evaluation of measured data are obtained. The algorithms, based on standard profiles with free parameters, have been adjusted to the data resulting from angle resolved XPS (ARXPS) by means of least squares fits. Depth profile analyses and segregation studies were performed on Pt-Ni and Fe-S specimens.

Journal Article↗
PubMed1995

A unique case of tardive dystonia induced by short-term therapy with perazin.

Perazin is a piperazine derivative of phenothiazine with higher affinity for the D2 than the D1 receptor. We observed a 43-year-old woman who developed blepharospasm and oral hyperkinesia as a tardive dystonic syndrome after short-term treatment with perazin. She had never taken any other neuroleptic medication and all known forms of secondary dystonia were ruled out. We were unable to find any previous reports of perazin-induced tardive dystonia.

Adult↗
PubMed1995

Stereotactic cysto-ventricular shunting in diencephalic (arachnoid) cysts and failure in cystic craniopharyngeoma.

Stereotactic cysto-ventricular shunting in three patients with congenital (subependymal cyst of the 3rd ventricle, subependymal cyst of the foramen of Monro, cyst of cavum septi pellucidi) and in a female patient with a large cystic suprasellar craniopharyngeoma is dealt with in this paper. The first operation was performed in May 1992 and the latest, being considered in this paper, in October 1993. All patients were admitted to our hospital suffering from signs of increased intracranial pressure. CT-scans revealed on the one hand an obstructive hydrocephalus subjected to the cystic arachnoid lesions, on the other hand a large hypodense suprasellar cystic tumor. After stereotactic puncture of the arachnoid cysts, aspiration of their contents as well as biopsy of the wall, a silicone catheter was implanted, thus constructing a permanent communication between the cyst and the lateral or third ventricle. The internal catheter was connected to a subcutaneous burr-hole reservoir. All these patients recovered uneventfully without neurological deficits. There were no operative complications. Follow-up CT-scans showed no recurrences of the cysts and obstructive hydrocephalus. In the patient with the suprasellar craniopharyngeoma at first a stereotactic puncture of the cyst was performed. After recurrence the tumor was directly approached by an frontotemporal craniotomy. The histological examination revealed now a craniopharyngeoma. After renewed recurrence a stereotactic cysto-ventriculostomy with internal shunt implantation was performed. However, in this case this method was unsuccessful, documented by follow-up CT-scans. Resulting from our experiences, it is quite obvious that the stereotactic internal shunt implantation seems to be a safe, proper and reliable method in the treatment of arachnoid cystic lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗