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Biomedical subjects

R Bauer

Publications and source records attributed to R Bauer.

At least 361 records · Page 20Linked to original sources
PubMed1989

[Lack of effectiveness of coenzyme Q10 (ubiquinone) in long-term treatment of dilated cardiomyopathy].

In a chronic, placebo-controlled, double-blind cross-over study a potential therapeutic effect of coenzyme Q10 (ubiquinone) was investigated in 25 patients suffering from dilative cardiomyopathy (NYHA functional class I, II, III). During a period of four months patients were treated with 3x 33.3 mg of coenzyme Q10 per day, given orally, 15 patients received verum during the first four months and placebo during the following four months (V/P). In the second group of patients (n = 10) the sequence of treatment was reversed (P/V). Therapeutic effect was assessed by means of echocardiogram, chest x-ray, radionuclide ventriculography combined with exercise test and impedance cardiography. Control values for left ventricular function parameters were similar in both groups (left ventricular ejection fraction: 39.5 +/- 11.5% (P/V), 37.6 +/- 17.0% (V/P); left ventricular enddiastolic diameter: 65 +/- 9 mm (P/V), 67 +/- 8 mm (V/P); Cl: 5.1 +/- 1.4 l/min (P/V), 5.1 +/- 1.1 l/min (V/P]. Chronic treatment by coenzyme Q10 did not exhibit any influence on hemodynamic parameters, on the electrocardiogram, on incidence of ventricular arrhythmias, or on exercise tolerance. It was not possible to demonstrate any therapeutic effect of coenzyme Q10 in patients with dilative cardiomyopathy.

Adult↗
PubMed1989

[Principles and developmental status of scintigraphy and nuclear magnetic resonance tomography].

Scintigraphy is performed by means of radiopharmaceuticals which accumulate in the target organ or remain in the intravascular space. Radiopharmaceuticals consist of radionuclides as atoms or ions, or of radionuclides incorporated in simple or complex compounds, or in labeled endogenic cells. The gamma rays or gamma quanta are detected by using gamma cameras. Precise localization and image formation is performed by collimation. Sensitivity decreases quadratically with increasing resolution owing to the imaging procedure. Planar scintigrams represent summation images showing a resolution of 5 mm when structures close to the detector are imaged, and a reduced resolution of 8 to 10 mm when structures at a distance of 10 cm are investigated. Usually scintigrams are stored in digital form in a computer. Investigation of cardiac function by means of radionuclide ventriculography requires ECG triggering. Cardiac function is visualized by a so-called representative cardiac cycle consisting of 16 to 32 planer images. In single photon emission computed tomography (SPECT or ECT), transversal tomograms are reconstructed from original data of 60 to 120 planar scintigrams which are recorded with the head of the gamma camera rotating around the long axis of the patient. Resolution is approximately 15 mm. Positron emission tomography (PET) utilizes positron emitting radionuclides. Positrons recombine with electrons after a short, free path of some millimeters. Consequently, two gamma quanta are emitted into opposite directions (almost 180 degrees) which are detected by means of a detector ring system and coincidence techniques. Resolution is as good as 5 mm. PET studies are performed most effectively in the close vicinity of a cyclotron that can produce the short-lived positron emitters with typical half-lives of only some minutes. The new imaging modality nuclear magnetic resonance tomography (MRT) allows for recording tomograms in arbitrary orientation in space from very weak electromagnetic resonance signals. The information of the images resembles the density of endogenic protons which is weighted with two relaxation times and modified by flow phenomena. Those tomograms show excellent soft tissue contrast. To date, resolution is 1 mm within 5-mm-thick slices. ECG triggering is mandatory for cardiac imaging. With spin echo mode, recording 8 to 12 parallel tomograms at 8 to 12 equidistant points in time within the cardiac cycle takes 5 to 8 min depending on heart rate. Applying gradient echo mode, up to 30 different tomograms can be recorded within the same acquisition time showing one slice or a set of parallel slices at successive, equidistant cardiac phases. Nuclear magnetic resonance spectroscopy provides metabolic investigations in vivo.

Heart Diseases↗
PubMed1989

[Intraoperative monitoring of spinal interventions with evoked potentials].

Monitoring the spinal cord can improve the safety margin during spinal surgery. This technique requires a stimulus source, transmitted through filters and amplifiers, and resulting in an enhanced signal that is recorded. Several techniques are now available, both non-invasive and invasive. We have carried out intraoperative monitoring during 178 spinal operations to correct deformities. Cortical somatosensory evoked potentials (CSEP) were obtained with Fz-Cz' recording sites, following bilateral posterior tibial nerve stimulation. In addition, unilateral median nerve stimulation was performed as a control. Six cases with an intraoperative alteration in waveform are described.

Adolescent↗
PubMed1989

[Asymptomatic course of severe tricuspid valve insufficiency with ateroseptal infarct, coronary fistula and ventricular septum defect as a sequela of blunt thoracic trauma].

Traumatic tricuspid valve insufficiency is a rare in vivo finding, especially in combination with other traumatic cardiac injuries like ventricular septal defect, myocardial infarction, and traumatic coronary fistula. Two-dimensional and, more recently, colorcoded Doppler echocardiography have gained importance for the diagnosis of tricuspid insufficiency. Patients with traumatic tricuspid insufficiency who survive the acute trauma, may remain asymptomatic for many years and even decades. If symptoms develop, tricuspid valve replacement appears feasible even after many years.

Adult↗
PubMed1988

[Combined topical treatment of acne with erythromycin and tretinoin].

Vitamin A acid is the most effective comedolytic agent in the therapy of acne vulgaris. Antibiotics are suitable for the treatment of inflammatory lesions (papulo-pustules). Even topically applied, some antibiotics show a sufficient anti-inflammatory effect. Above all, erythromycin is reliable in the topical treatment of acne. Combined therapy with both topical tretinoin and erythromycin is more effective than either alone. During the first weeks of treatment, tretinoin leads to temporary deterioration of the disease, which can mostly be avoided by the anti-inflammatory effect of erythromycin simultaneously applied.

Acne Vulgaris↗
PubMed1988

[Type IV immunity in alopecia areata in a comparison of 2 test methods].

69 patients with alopecia areata of different degree and duration were tested for cell-mediated immunity (DCH) by means of the Multitest system and other recall antigens. Our findings revealed a normergic status in most of the patients. In comparison with healthy controls, however, these patients showed decreased cell-mediated immunity, which was proved by a diminished score and a reduced number of positive reactions. There was no correlation between an anergic or hypoergic status on the one hand, and the degree or duration of the disease on the other.

Adult↗
PubMed1988

[Scleromyxedema therapy with isotretinoin].

We report on a 56-year-old male patient suffering from scleromyxedema, who was successfully treated with isotretinoin (13-cis retinoic acid, Roaccutan). After 10 months therapy, we observed considerable reduction of the cutaneous infiltration and the skin thickening; the papular eruptions had almost completely disappeared. The mobility of the joints, however, could only be slightly improved.

Drug Administration Schedule↗
PubMed1988

Coherent oscillations: a mechanism of feature linking in the visual cortex? Multiple electrode and correlation analyses in the cat.

Primary visual coding can be characterized by the receptive field (RF) properties of single neurons. Subject of this paper is our search for a global, second coding step beyond the RF-concept that links related features in a visual scene. In recent models of visual coding, oscillatory activities have been proposed to constitute such linking signals. We tested the neurophysiological relevance of this hypothesis for the visual system. Single and multiple spikes as well as local field potentials were recorded simultaneously from several locations in the primary visual cortex (A17 and A18) using 7 or 19 individually advanceable fiber-microelectrodes (250 or 330 microns apart). Stimulus-evoked (SE)-resonances of 35-85 Hz were found in these three types of signals throughout the visual cortex when the primary coding channels were activated by their specific stimuli. Stimulus position, orientation, movement direction and velocity, ocularity and stationary flicker caused specific SE-resonances. Coherent SE-resonances were found at distant cortical positions when at least one of the primary coding properties was similar. Coherence was found 1) within a vertical cortex column, 2) between neighbouring hypercolumns, and 3) between two different cortical areas. We assume that the coherence of SE-resonances is mediated by recurrent excitatory intra- and inter-areal connections via phase locking between assemblies that represent the linking features of the actual visual scene. Visually related activities are, thus, transiently labelled by a temporal code that signalizes their momentary association.

Action Potentials↗
PubMed1988

Cotrel-Dubousset (CD) instrumentation for the correction of spinal curvature. First results in special consideration of derotation.

At the University of Innsbruck, Department of Orthopedics, 30 scoliosis patients were operated on using the surgical method according to Cotrel-Dubousset in the period of May 1986-December 1987. For the correction of the curvature this instrumentation uses both distractive as well as transverse forces and attains such an unusual primary stability that postoperative immobilization by brace becomes unnecessary. In addition, it permits the three-dimensional correction of scoliosis curvatures. With an average preoperative measurement of 65.4 degrees and a postoperatively measured angle of 23.8 degrees the correction achieved is 64%. Rotation of the scoliosis was reduced by 39%. Our experiences with the application of the described method of operation and the pertinent complications are described below.

Adolescent↗
PubMed1988

A new tremelloid yeast isolated from Asterophora lycoperdoides (Bull.: Fr.) Ditm.

Reports of a yeast stage of the homobasidiomycete Asterophora lycoperdoides were reexamined. Substantial differences in the physiological description and a gap of 11% G + C content were detected between the yeast and the mycelium. On the basis of nDNA reassociation experiments and restriction enzyme cleavage patterns of mtDNA using two different enzymes it has been concluded that the yeast strains and the mycelia are probably not the same species. The results of earlier reports about the life cycle, however, cannot be explained with these data. This yeast is newly described, because it shows unique physiological properties and no significant homology in DNA-DNA reassociation experiments to species it would normally be identified with in the literature. Because of its dolipore with cup-shaped parenthesome, we prefer the term tremelloid over assigning the strains to any existing genus, because no sexual structure or ballistospore has been observed so far.

Culture Media↗
PubMed1988

Spontaneous and induced chromosomal instability in Werner syndrome.

In extension of a previous study, spontaneous and clastogen-induced chromosome damage was analyzed in cultures of peripheral blood lymphocytes from six further patients with Werner syndrome (WS) and six healthy controls. In addition, sister chromatid exchange (SCE) was estimated in four of these cases. Lymphocytes of patients with various other diseases were used for another series of control experiments. Diepoxybutane (DEB), 4-nitroquinoline-1-oxide (NQO), and bleomycin (BLM) were the standard clastogens throughout the study. While the spontaneous frequency of chromosomal breakage was significantly higher in lymphocytes from all the patients than in the control cells, the basis SCE rate was unaffected in WS cells. Sensitivity of WS cells to the chromosome-damaging action of BLM did not differ from that of control cells, and their sensitivity to DEB was slightly greater than that of control lymphocytes. However, NQO induced a more distinct increase of both break and interchange aberrations in the WS cells than in control cells or cells from patients with other diseases. This effect was not found for the SCE rate. Our data demonstrate the exceptional cytogenetic features of this syndrome: Although the spontaneous and the DEB- and NQO-induced chromosomal breakage rate would suggest that WS is like a classic chromosomal instability syndromes, the lack of sensitivity of WS cells to bleomycin and their stable SCE frequency compared with that of control cells clearly delimitate this syndrome from other entities.

4-Nitroquinoline-1-oxide↗
PubMed1988

Reaction of human keratinocytes with the monoclonal antibody anti-Leu-11: an immunohistologic study.

Biopsy specimens from skin of 99 patients with 26 different dermatoses and 17 specimens from normal skin were labeled with regard to the reactivity of keratinocytes with the monoclonal natural killer-associated antibody anti-Leu-11b by means of the avidin-biotin-peroxidase complex method. Reactivity occurred in 64.7% of the preparations from normal skin and in 84.8% of the preparations from diseased skin. The membranes of the subcorneal keratinocyte layers were labeled regularly. In some of the preparations cytoplasmic reactivity and labeling of the basement membrane zone occurred in addition. Most labeled preparations and the highest labeling intensities were shown in the skin tumors and in the infectious dermatoses. The biologic significance of this finding is discussed.

Antibodies, Monoclonal↗
PubMed1988

Acitretin versus etretinate in psoriasis. Clinical and pharmacokinetic results of a German multicenter study.

175 patients with severe psoriasis of different types were treated with 10, 25, or 50 mg acitretin and compared with patients receiving 50 mg etretinate over a period of 8 weeks in a randomized, double-blind multicenter study in the Federal Republic of Germany. Plasma concentrations of etretinate and its metabolite acitretin were measured during therapy and also 3 weeks after cessation of treatment. After 4 weeks of treatment, a trend toward clinical improvement was shown in all groups with increasing dosage. Those groups receiving the lower acitretin doses (i.e., 10 and 25 mg/day) had more dropouts than the groups taking 50 mg acitretin or 50 mg etretinate. Complete remissions before the end of therapy occurred only among those receiving higher doses. Enlargement of psoriatic lesions, however, could be observed during treatment with both retinoids, despite improvement of other parameters, as measured by psoriasis area and severity index (PASI) and psoriasis severity index (PSI). After 8 weeks, a significant improvement was calculated by the PASI score and by a newly defined, corrected PASI score for all four dose regimens compared with baseline levels. A greater than 50% PSI score improvement was seen in 50% of patients treated with 10 mg acitretin, 40.5% with 25 mg acitretin, 53.8% with 50 mg acitretin, and 61.1% with 50 mg etretinate. No statistical differences were found among these groups at any time during the 8-week period. No new or unexpected side effects occurred during acitretin treatment. Moreover, cholesterol levels did not significantly change. Three weeks after cessation of drug administration, the plasma concentrations of acitretin were below the sensitivity level of the assay, whereas etretinate was still quantifiable. It is interesting that acitretin plasma concentrations during therapy with 50 mg acitretin were markedly lower (means = 18 ng/ml) than were acitretin levels during treatment with 50 mg etretinate (means = 36 ng/ml).

Acitretin↗
PubMed1988

Differential expression of major histocompatibility complex class II antigens on human keratinocytes.

Skin biopsies from 136 patients with 30 different dermatoses and eight biopsies of normal skin were investigated with the avidin-biotin-peroxidase complex method with regard to the expression of major histocompatibility complex class II antigens human leukocyte antigen (HLA) HLA-DR, HLA-DQ, HLA-DP on keratinocytes. In normal skin the expression of these antigens was restricted to acrosyringia and Langerhans cells. In the dermatoses investigated HLA-DR was found in 51.5% (70 of 136), HLA-DQ in 24.3% (33 of 136), and HLA-DP in 20.5% (8 of 39). In 37 cases (27.2%) only HLA-DR could be detected, whereas in 33 cases (24.3%) HLA-DR was expressed jointly with HLA-DQ. Coexpression of HLA-DR and HLA-DQ was found especially often in cutaneous T cell lymphomas, skin tumors, and inflammatory dermatoses.

Epidermis↗
PubMed1988

Mechanical lithotripsy of bile duct stones in 209 patients--effect of technical advances.

Between 1982 and 1987, mechanical lithotripsy of common bile duct (CBD) stones was performed in 209 patients (mean age +/- SD: 72 +/- 10 years), using self-constructed lithotripters and baskets with breaking strengths of approximately 50 and 100 kg between 1982 and 1986, and stronger and bigger baskets with breaking strengths of approximately 125 kg since 1987. Patients with single (49.3%) and multiple stones (50.7%) were distributed about equally. Stone size ranged between 4 and 80 mm (mean longitudinal diameter 18 +/- 9 mm, mean transversal diameter 13 +/- 3 mm), with a majority of the patients (61.2%) having stones of between 10 and 19 mm, and about one-third (32.1%) of the patients with stones greater than or equal to 20 (20-80) mm. The overall success rate of mechanical lithotripsy in all 209 patients treated between 1982 and 1987 was 87.6% including 79.1% for CBD stones greater than or equal to 20 mm and 67.6% for stones greater than or equal to 25 mm. The introduction of baskets with breaking strengths of approximately 125 kg in 1987 considerably increased the success rate of mechanical lithotripsy, especially for "large and giant" CBD stones, to 92.3% (greater than or equal to 20 mm) and 85.7% (greater than or equal to 25 mm), respectively.

Aged↗
PubMed1988

Intraoperative somatosensory potential monitoring. A clinical analysis of 127 surgical procedures.

During 127 operations for the correction of spinal deformities the spinal cord function was controlled by intraoperative monitoring. Cortical somatosensory evoked potentials (CSEP) were obtained by bilateral stimulation of the posterior tibial nerves at the ankle and recorded from electrodes at Fz-Cz. In addition, unilateral median nerve stimulation at the wrist was carried out to act as a control. Six cases with significant intraoperative alterations in wave-form and their postoperative neurologic status are described in detail. EP monitoring permits continuous monitoring of the patient for the total duration of operation and is therefore superior to the wake-up test. This method is particularly advisable for operations carried out in hypotensive anaesthesia as well as for postoperative control.

Adolescent↗
PubMed1988

Anti-Leu 19 monoclonal antibody detects an antigen on autonomic nerves in human skin.

The monoclonal antibody anti-Leu 19 recognizes the NKH-1 antigen of active natural killer cells. In immunohistological preparations of the skin, the antibody reacts with cutaneous nerves and labels nerve fibers in the region of the sweat glands, the blood vessels and the hair arrector muscles. This staining pattern corresponds to the distribution of the autonomic sympathetic nervous system of the skin. On the other hand, anti-Leu 7 labels a myelin-associated glycoprotein which is to be found in the myelin sheath of sensory cutaneous nerves. The reactivity of neural structures of the skin can thus be differentiated. Anti-Leu 7 labels the myelinated sensory nervous system, whereas anti-Leu 19 seems to constitute a new marker for the autonomic nervous system of the skin.

Antibodies, Monoclonal↗