Direct observation of surface chemical order by scanning tunneling microscopy.
Explore the source record for details and available documents.
Journal Article↗
Biomedical subjects
H Stadler
Publications and source records attributed to H Stadler.
[Ethical principles in rehabilitation].
Set out and discussed are fundamental social-ethical issues in rehabilitation concerning the right to live, human dignity, personal growth, participation in working life, as well as recreation/vacation main-streaming. The fundamental social-ethical position posited is one of acceptance of disability in every phase of human life, practically expressed in terms of trusting in the benefit of educational enhancement even in severe disability, as well as in assuming responsibility for disabled persons' living conditions.
Adolescent↗
Lattice mismatch dislocations in a preferentially sputtered alloy studied by scanning tunneling microscopy.
Explore the source record for details and available documents.
Journal Article↗
[Independent living skills for physically handicapped students with profound disability].
Traditional educational curricula are inadequate for physically disabled students with very severe consequences of disablement, as they are insufficiently geared toward building Independent Living skills. Typical of their post-school situation nowadays, only few of them are in a position of making a direct transition into vocational training. The majority continues to need intensive educational-therapeutic services. The schools for the physically disabled seek to smoothen their transition into adult life by leaving-grade programmes aimed at providing opportunities for work-related experience as well as at building coping skills for day-to-day living. The work and life preparation programme represents a special organizational and didactical conception in this context, where the demands of adult life serve as the starting point for developing the learning and educational goals to be attained.
Activities of Daily Living↗
[Handicap--negative variant of the "normal"--or else? Comments on the problem of attitude to deficits in rehabilitation and ethical principles].
Uncertainty as to what exactly is comprised by disability is quite frequently encountered not only in the general public but also among rehabilitation workers. The "normal" is deemed the desirable, and "disability" turns into its negative counterpart. Attention is focussing on the deficits that appear on measuring and comparing. A critical discussion of deficit orientation in education and care of disabled persons is needed. Isolated identification of and attendance to deviations must be overcome by interdisciplinarity and team work, in order to pay due respect to the person as a whole, to his or her social and personal identity. Also, fundamental issues of the current ethics discussion in special education arise in this context. Shown on the example of J. J. Rousseau, reference to philosophical or educational "authorities" may turn out to be misguided.
Adaptation, Psychological↗
Ro 42-5892 is a potent orally active renin inhibitor in primates.
The goal of the present study was to characterize the new renin inhibitor Ro 42-5892 in vitro and in vivo. In vitro, Ro 42-5892 inhibited purified human renin and human plasma renin specifically with an IC50 of 0.7 nM and 0.8 nM, respectively. In vivo, Ro 42-5892 reduced mean arterial blood pressure in sodium-depleted marmosets and squirrel monkeys with as low a dose as 0.1 mg/kg orally. Higher doses reduced pressure by 30-35 mm Hg in both species. The duration of blood pressure decrease with 3 mg/kg orally was more than 24 hours. Maximal changes of plasma renin activity, immunoreactive angiotensin I, and immunoreactive angiotensin II were observed at 15 minutes. Renin was reduced by 74 +/- 31%, angiotensin I by 85 +/- 14%, angiotensin II by 89 +/- 17%, and immunoreactive active renin was increased by 70 +/- 39%. However, unlike pressure, these maximal effects were only transient with complete recovery of renin at 60 minutes under still reduced levels of angiotensin I (61 +/- 24%) and angiotensin II (71 +/- 38%) and increased concentrations of active renin (86 +/- 30%). The blood pressure lowering was due to specific renin inhibition as exemplified by the influence of the kidney, sodium status, species, or stereoselectivity. Moreover, the reduction of arterial blood pressure was similar to the action of the angiotensin converting enzyme inhibitor cilazapril and was not associated with reflex tachycardia in contrast to the pure vasodilator minoxidil. We conclude that Ro 42-5892 is a potent orally active renin inhibitor acting mainly by inhibition of renin in an extraplasmatic compartment.
Administration, Oral↗
[Ethics and handicap--a critical review].
Explore the source record for details and available documents.
Abortion, Induced↗
[Didactic problems of education and instruction of patients with craniocerebral trauma].
While concepts for the solution of didactical-methodological problems are available for brain-injured children and young people, such concepts are almost nonexistent for adults with craniocerebral trauma sequels. A case example is presented from an educationist perspective, illustrating the disruptive impact of craniocerebral trauma on the person's biography. Didactical and methodological problems not only arise from deficient cognitive functioning but also due to the psychosocial impact of severe brain trauma. Inter alia dealt with is the question of whether an independent didactical approach is needed, or whether concepts derived from general didactics can be applied. For learners with craniocerebral trauma, "learning theory-based didactics" is an especially suitable model; a brief description is given, and its application to the specific situation of this population outlined. People with brain trauma display problems in knowledge acquisition and concept formation (cognitive learning), in transfer of learning content and performance control. Though an independent didactical concept may not be necessary, it is however crucial that in respect of the teaching/learning processes in this population, due attention is being paid to methodological principles applied in the special education field.
Adolescent↗
Ionic channels in synaptic vesicles: are they involved in transmitter release?
Synaptic vesicles were isolated from the nerve terminals of Torpedo electric organ. After fusion, 'giant' vesicles were formed which could be examined by the patch clamp technique. One of the cationic channels, the P channel, shows a small preference for K+ compared to Na+ and has multiple conductance levels. Its rate of opening is voltage and calcium dependent. Fractal analysis of the P channels reveals that its behaviour does not seem to be fractal in nature. At voltages where only one conductance level is observed, fractal analysis shows at least one discrete open state and at least two discrete closed states. There are considerable similarities between the P channel and channels found in granules from the hypophysis. These channels resemble, in turn, the channels found in gap junctions. Therefore, it is not unwarranted to speculate that a gap-junction-like communication between the secretory vesicle and the extracellular space may occur during exocytosis.
Animals↗
Uptake of GABA by rat brain synaptic vesicles isolated by a new procedure.
Uptake of GABA was demonstrated in rat brain synaptic vesicles which were prepared by a new and efficient procedure. The uptake activity co-purified with the synaptic vesicles during the isolation procedure. The purity of the vesicle fraction was rigorously examined by analysis of marker enzymes and marker proteins and also by immunogold electron microscopy using antibodies against p38 (synaptophysin). Contamination by other cellular components was negligible, indicating that GABA uptake by the synaptic vesicle fraction is specific for synaptic vesicles and not due to the presence of other structure possessing GABA uptake or binding activities. GABA uptake was ATP dependent and similar to the uptake of glutamate, which was assayed for a comparison. Both uptake activities were independent of sodium. They were inhibited by the uncoupler carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone, indicating that the energy for the uptake is provided by an electrochemical proton gradient. This gradient is generated by a proton ATPase of the vacuolar type as suggested by the effects of various ATPase inhibitors on neurotransmitter uptake and proton pumping. Competition experiments revealed that the transporters for GABA and glutamate are selective for the respective neurotransmitters.
Adenosine Triphosphatases↗
[Changes in the urinary protein pattern in SDS polyacrylamide gel electrophoresis in normal and hypertensive pregnancies].
The urinary protein pattern was determined in 46 healthy male and female subjects, 64 patients with an uncomplicated course of pregnancy and 88 hypertensive pregnant women by use of a special urine preparation and a modified SDS-polyacrylamide gel electrophoresis (SDS-PAGE). There were no differences in the protein electrophoresis pattern between the control subjects, independent of sex and age, and the pregnant women. The number of protein bands did not change in the course of pregnancy and in the post partum period. In both groups, an intensively stained protein band with an apparent molecular weight of 105 kD was detected. In 71 of the 88 hypertensive pregnant women we found a marked reduction in intensity or complete disappearance of the 105 kD protein band. Follow-up analysis in 30 of these pregnant women showed, that in 24 cases disappearance of the 105 kD band occurred simultaneously with and in 6 women before clinical manifestation of the disease. There were no differences in the protein electrophoresis pattern between patients with preexisting renal or hypertensive disease and hypertensive women without a complicated history. In 49 of the 52 hypertensive pregnant women complete reappearance of the 105 kD band was observed 2 to 14 days after delivery. By using silver staining and Western blot, the 105 kD band was identified as Tamm-Horsfall protein. Our findings may reflect a transitory tubular dysfunction in cases of preeclampsia and support the hypothesis of an immunological pathogenesis of the disease.
Adolescent↗
Ion channels in synaptic vesicles from Torpedo electric organ.
A simple method has been developed for fusing synaptic vesicles into spherical structures 20-50 micron in diameter. The method has been applied to purified cholinergic synaptic vesicles from Torpedo electric organ, and the membrane properties of these fused structures have been studied by the "cell"-attached version of the patch clamp technique. A large conductance potassium-preferring channel, termed the P channel, was consistently observed in preparations of fused synaptic vesicles. The selectivity of the channel for potassium over sodium was approximately equal to 2.8-fold. Two major conductance levels were observed during P-channel activity, and their relative proportion was dependent on the voltage applied to the membrane through the patch pipette. P channels were not seen in fused preparations of purified Torpedo lipids, nor was the frequency of their occurrence increased in preparations enriched with plasma membrane or nonvesicular membranes. We suggest, therefore, that the P channels are components of the synaptic vesicle membrane. Their function in synaptic transmission physiology is still unknown.
Animals↗
Cholinergic vesicle specific proteoglycan: stability in isolated vesicles and in synaptosomes during induced transmitter release.
Exposure of synaptosomes isolated from the electric organ of Torpedo marmorata to conditions that promote the release of acetylcholine does not cause the co-release of a vesicle specific proteoglycan. Proteoglycan within synaptosomes is quite stable during various incubation conditions as measured by immune dot blotting. Isolated vesicles from Torpedo also retain their proteoglycan immunoreactivity when exposed to a variety of incubation conditions. Lysis of vesicles in H2O, treatment with pH 11.5 buffer, or exposure to high ionic strength (2 M KCl) results in the loss of acetylcholine or ATP while the proteoglycan is retained by vesicle membranes. Only treatment with Nonidet P-40 releases proteoglycan from vesicles or synaptosomes and free proteoglycan immunoreactivity is then susceptible to degradation by trypsin or heparinase. These results suggest that the proteoglycan is an integral component of vesicle membranes and is at least in the synaptosomal preparation not subject to extensive co-release with acetylcholine or ATP.
Acetylcholine↗
Synaptic vesicles in electromotoneurones. I. Axonal transport, site of transmitter uptake and processing of a core proteoglycan during maturation.
We were able by using an in vivo pulse-label technique to trace part of the life cycle of a secretory organelle, the acetylcholine-storing synaptic vesicle from electromotoneurones of Torpedo marmorata. This technique uses [35S]sulphate incorporation into the cell bodies of the electromotoneurones which results in radioactive labelling of a synaptic vesicle heparansulphate proteoglycan--a major core component. Vesicles are anterogradely transported in the axons at a fast rate as 'empty' organelles (VP0 population). In the nerve terminal, maturation of the granule to a population (VP1) fully charged with acetylcholine and ATP occurs. Finally after a longer time interval a change to a third population (VP2) is observed. This population is reduced in diameter as compared to VP0 and VP1 suggesting, in agreement with earlier reports, that it has undergone exo-endocytosis. The changes from VP0 to VP1 and VP2 are accompanied by a degradation of the core proteoglycan as measured by gel filtration of the 35S-labelled compound. The results show that vesicles are axonally transported as preformed organelles, exist in the neurone at least in three different populations and that the nerve terminal is the major site of transmitter uptake.
Acetylcholine↗
Synaptic vesicles in electromotoneurones. II. Heterogeneity of populations is expressed in uptake properties; exocytosis and insertion of a core proteoglycan into the extracellular matrix.
The three populations of synaptic vesicles in electromotor nerve terminals were analysed quantitatively. Empty vesicles (VP0), fully charged vesicles (VP1) and charged but smaller VP2-type vesicles are present in approximately equal amounts in the nerve terminal. The populations show differences in the kinetics of in vitro uptake of acetylcholine, ATP and Ca2+. VP0 and VP2 accumulate acetylcholine and ATP but no Ca2+, whereas VP1 shows negligible acetylcholine and ATP but high Ca2+ uptake. Thus the expression of uptake properties of this secretory organelle depend on the stage it has reached in its life cycle and might constitute a signal for processing. VP2 was found to contain much less core proteoglycan than VP0 and VP1 indicating that part of it has been lost by exocytosis. In synaptic extracellular matrix containing fractions an antigen is detectable that cross-reacts with an antiserum against the vesicle proteoglycan. This material elutes upon gel filtration in a position similar to a smaller form of proteoglycan found in vesicles. We conclude that the electromotor nerve terminal releases a proteoglycan by the regulated secretory pathway that is deposited in the extracellular matrix. It might have a function in keeping pre- and postsynaptic structures in alignment constituting a transsynaptic signal. Based on the findings described, a model of the vesicles' life-cycle is discussed, whereby the VP2 population is the major source of quantal release of acetylcholine.
Animals↗
The proton pump of synaptic vesicles.
Explore the source record for details and available documents.
Animals↗
Identification of a synaptic vesicle antigen (Mr 86,000) conserved between Torpedo and rat.
Antisera were raised in guinea pigs to synaptic vesicles purified from the electric organ of Torpedo marmorata. In cholinergic nerve terminals from Torpedo the major antigens identified had Mr 300,000-150,000, 86,000, and 18,000. The Mr 86,000 antigen was conserved between Torpedo and rat, where it is neuron-specific and concentrated in nerve terminals. When rat brain synaptosomes are subfractionated the antigen is associated with synaptic vesicles. The antigen is not found in the cytoskeleton and in the vesicle-free cytosol. Immunohistochemical localization of the antigen in rat shows it to be associated with synapses in diaphragm, cerebellum, hippocampus, and cerebral cortex. The staining pattern of the antigen indicates that the antigen is not cholinergic-specific. The function of the Mr 86,000 antigen remains to be identified.
Animals↗
[Conservative therapy of upper gastrointestinal hemorrhage (prospective, randomized, controlled)].
In this prospective study for pharmacotherapy of non varicial upper gastrointestinal haemorrhage eight therapy groups were examined. The efficacy of the most important drugs for ulcus disease was considered. The drugs were used alone and in combination. The results indicated no favourable effect of one preparation (Cimetidine, Pirenzepine, Ranitidine). Significant benefit for the long time healing rate was noted among the combination therapies, especially with Sucralfate, which was not used alone.
Aluminum↗