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Biomedical subjects

R Bauer

Publications and source records attributed to R Bauer.

At least 487 records · Page 27Linked to original sources
PubMed1981

[Assessment of haemodynamic parameters using a scintillation camera and ECG-triggered data acquisition (author's transl)].

Useful ECG-gated scintigrams of the heart can only be obtained when using a suitable tracer (99mTc-HSA or labeled red cells), a good camera and a computer system with special hard and software. The haemodynamic parameters of left (and right) heart function as derived from scintigrams are only precise when the representative cycle was reconstructed correctly. In patients with arrhythmia, counts should be only summed up when the cardiac cycle follows a preceding heart beat of well defined length. The frames composing the representative cycle must be normalized to the same recording time. When these prerequisites are fulfilled, correct values for ejection fraction and maximal rates of systolic emptying and diastolic filling as global parameters of heart function can be derived. Evaluation of these parameters by means of a completely automated computer program is difficult in pathologically altered heart function. In our nuclear medicine department an interactive computer program has been developed which supplies the investigator with certain information facilitating the definition of the end-diastolic and end-systolic ROI. The program allows for an exact and reproducible evaluation within a short time. Functional images of both amplitudes and phases are very helpful. Functional scintigraphy of the heart is only possible when using certain instrumentation, which is much more expensive than when using a 'cardiac probe', but the additional visual information obtained does significantly improve diagnostic sensitivity.

Arrhythmias, Cardiac↗
PubMed1980

Responses of vestibular nucleus neurons in the visually deprived cat to optokinetic stimulation of central parts of the visual field.

Single cells were recorded in the vestibular nucleus of normal and monocularly deprived cats and stimulated by slowly drifting large area visual patterns. We found no difference in response strength, direction specificity and binocular influence between the neurons recorded in normal and in monocularly deprived cats. This makes it very unlikely that the nucleus of the optic tract (NOT) in the pretectum provides a strong direct input to the vestibular nuclei to modulate their activity with visual stimulation.

Animals↗
PubMed1980

Laminar distribution of preferred orientations in foveal striate cortex of the monkey.

Microelectrode penetrations normal to the layers of foveal striate cortex in awake, behaving monkeys have revealed two new facts about the distribution of orientation preferences in this tissue: (1) In the top layers there is a predominance of vertical orientation preferences at eccentricities of less than 30 min, and a predominance of oblique orientation preferences at eccentricities of 30 min to 2 deg. (2) At all eccentricities between 0 and 2 deg there is a striking difference in orientation preference between upper layer (supragranular) and lower layer (infragranular) cells.

Animals↗
PubMed1980

Visual-vestibular convergence in the vestibular nuclei of the cat.

Responses from neurons of the vestibular nuclei were recorded in N2O-anaesthetized cats. Most neurons in the rostral parts of the nuclei responded to bimodal visual-vestibular stimulation, following a trapezoidal velocity profile. Both combinations of the two stimuli were tested: rotation of the animal with stationary visual field and rotation with overtaking visual field, i.e. the visual pattern running in the same direction as the turntable with twice the velocity. Some correlation of physiological data with results in corresponding psychophysical experiments were found. As a possible biological function of visual-vestibular convergence a phylogenetic solution for discrimination of body and outer world movement is discussed.

Animals↗
PubMed1980

[Living Sézary cells in vitro: formation of autologous rosettes (author's transl)].

Living Sézary cells are more clearly discernible in supravital preparations using a phase contrast microscope than in stained blood smears. Especially, the small variant of the Sézary cell can easily be identified by this simple technique. Lymphoblasts are unequivocally discernible from monocytes, since functional criteria of the living cells can be evaluated in supravital preparations in addition to morphological characteristics. Using this technique a remarkable phenomenon was seen in living Sézary cells: interactions between autologous erythrocytes and the atypical lymphocytes created autologous rosettes. The binding of erythrocytes with a typical lymphocytes was so stable that even with good motility of the Sézary cells the erythrocytes adhered to the surface of the lymphocytes. The ability of living Sézary cells to build rosettes with autologous erythrocytes in vitro is taken as an indication that living Sézary cells have membrane markers of thymocytes.

Aged↗
PubMed1980

Results of alloarthroplasty of the hip joint.

We report on the follow-up examination results of 881 operated hip joints which were implanted in the Innsbruck University Clinic for Orthopedics during the period 1968--1975. Due to exact checking 75% of all patients could be clinically control-examined during 1978 and all available information regarding the others was collected. In the patient group with an average age of 62.5 years the course of postoperative mobility over the years was mainly examined. Functional activity, subjective patient opinion, pain, work capability and weather sensitivity were also analyzed. After an implantation period of the hip prosthesis of 3--10 years encouraging results were shown. Aseptic prostheses loosenings (9.8%) were examined with regard to their causes. The infection rate was very low at 0.56% and also periarticular calcification only occurred comparatively seldom (13.5%). Other complications were recorded in 6.8% of the patients. In total, 74% of the operated patients offered a very good or good complete result.

Activities of Daily Living↗
PubMed1980

The osmotic behaviour of toad skin epithelium (Bufo viridis). an electron microprobe analysis.

The effect of saline adaptation on the intracellular Na, K, Cl, P concentrations and dry weight content of the toad skin epithelium (Bufo viridis) was studied using the technique of electron microprobe analysis. The measurements were performed on isolated abdominal skins either directly after dissection or after additional incubation in Ussing-type chambers. Adaptations of the toads to increasing NaCl concentrations for 7 days resulted in increased blood plasma osmolarity and a parallel increase in the cellular electrolyte, P and dry weight concentrations of the epithelium, the K increase representing the most significant fraction of the intracellular osmolarity increase. No evidence was obtained to show that the nucleus and cytoplasm reacted differently from each other and all living epithelial cell types basically showed the same response. Incubation of the isolated skins under control conditions showed a drastic inhibition of the transepithelial Na transport after adaptation to high salinities. In spite of the large variations in the transport rate almost identical intracellular electrolyte concentrations were observed. In tap water adapted toads the average cellular concentrations were 8.8 mmole/kg wet weight for Na, 109.6 for K, 41.5 for Cl, and 135.3 for P, respectively. Incubation of the skin with Ringer's solution of different osmolarities demonstrated that the epithelial cells are in osmotic equilibrium with the inner bathing solution. The results are consistent with the view that the osmotic adaptation is mainly accomplished by the movement of water.

Animals↗
PubMed1980

Cryolesions of bone. An experimental study. part II: Results of cryosurgery on bone.

After freezing-devitalisation of rabbit tibia bone, a slow resorption and substitution by new bone within a period of 6 months could be demonstrated. Intramedullary freezing combined with internal fixation of an osteotomy in the frozen area was followed by a delayed healing. Angiographic studies showed an almost normal circulation after freezing of the main vessels.

Angiography↗
PubMed1980

Electron microprobe analysis of intracellular elements in the rat kidney.

The concentrations of intracellular elements were determined by electron microprobe analysis in the nucleus and cytoplasm of freeze-dried cryosections of superficial proximal and distal tubules of the rat kidney. For the nucleus of the proximal tubular cell, the concentrations of sodium and chloride were 20 and 23 mmoles/kg of wet wt, and those of potassium and phosphorus were 144 and 150 mmoles/kg wet wt. For the nucleus of the distal tubular cell, the concentrations of sodium and chloride were significanlty lower (11 and 13 mmoles/kg wet wt), that of potassium was unchanged (143 mmoles), and that of phosphorus was significantly higher (175 mmoles). Towards the basolateral infoldings of the proximal and distal tubules and the brush border of the proximal tubules, the concentrations of sodium and chloride were higher and those of potassium and phosphorus were lower than those obtained in the nucleus, indicating the presence of extracellular compartments in these regions. Measurements performed in the centrally located cytoplasm of proximal and distal tubular cells, close to the nucleus, showed sodium and potassium concentrations to the indistinguishable from those in the nucleus, whereas chloride and phosphorus concentrations were considerably higher. These data demonstrate differences in the intracellular concentrations of phosphorus, sodium, and chloride between proximal and distal tubular cells. In neither the proximal nor the distal tubular cells, however, could a concentration difference for sodium and potassium between nucleus and cytoplasm be determined.

Animals↗
PubMed1980

[Long-term observation of osteochondrosis dissecans of the hip (author's transl)].

The article presents treatment results in a group of 21 patients (22 joints) suffering from osteochondrosis dissecans of the hip, the minimum observation period being 10 years (average 14 years). By means of surgical treatment, it was possible to achieve healing of the osteochondral fragments in nine out of 16 cases. Such healing was not achieved without surgical treatment; in two-thirds of these cases, an increasing osteoarthrosis of the hip was observed. Among the surgical measures, a combination of adduction osteotomy together with forage, yielded the best success quota (5 healings as a result of 5 operations), whereas adduction osteotomy without forage resulted in healing in 2 cases only out of a total of 16 operated patients.

Female↗
PubMed1980

[Pemphigus herpetiformis: a clinical variant of pemphigus vulgaris].

Two female patients are reported in whom the clinical picture closely corresponded to dermatitis herpetiformis Duhring or bullous pemphigoid, while acantholytic changes were present histologically. Indirect immunofluorescence revealed circulating pemphigus antibodies. Direct fluorescence showed deposits of IgG and complement in the intercellular space of the affected areas. One of the two patients responded well to DDS. There have been reports in the recent literature on bullous dermatoses, which can be regarded as morphological variants of pemphigus vulgaris. The term pemphigus herpetiformis is used here to designate these variants. The diagnosis can only be made by histological and immunological examinations in connection with the clinical picture.

Aged↗