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Biomedical subjects

A Baumann

Publications and source records attributed to A Baumann.

At least 109 records · Page 6Linked to original sources
PubMed1989

Molecular basis of functional diversity of voltage-gated potassium channels in mammalian brain.

Cloning and sequencing of cDNAs isolated from a rat cortex cDNA library reveals that a gene family encodes several highly homologous K+ channel forming (RCK) proteins. Functional characterization of the channels expressed in Xenopus laevis oocytes following microinjection of in vitro transcribed RCK-specific RNAs shows that each of the RCK proteins forms K+ channels that differ greatly in both their functional and pharmacological properties. This suggests that the molecular basis for the diversity of voltage-gated K+ channels in mammalian brain is based, at least partly, on the expression of several RCK proteins by a family of genes and their assembly to homooligomeric K+ channels with different functional properties.

4-Aminopyridine↗
PubMed1989

[Evaluating the success of surgery of incontinence. Analysis of pre- and postoperatively determined morphologic and functional findings].

Urodynamic and morphologic findings in 82 patients with stress urinary incontinence were analysed. All patients had undergone vaginal respectively abdominal hysterectomy with anterior colporrhaphy respectively urethrovesicopexy. Whereas in the abdominal group the urodynamic and morphologic findings improved significantly, this did not occur in the vaginal group (Colp. ant. group). Although a comparison of the postoperatively continent patients with the recurrent incontinence patients showed no significant difference, it seemed, however, that the recurrent incontinence patients frequently showed lower urodynamic and morphologic values.

Female↗
PubMed1989

The limits of decision analysis for rapid decision making in ICU nursing.

In a study examining rapid decisions in ICU nursing in the context of decision analysis, 40 nurses in 2 ICUs were asked to describe their decisions for six pretested vignettes, suggest alternatives and answer questions about case characteristics. Later, ICU charge nurses and educators were asked to rate the nurses' responses using a modified Q-sort. The nurses did not perceive a finite set of alternatives; the 40 nurses gave 36 to 40 unique sequences that did not cluster. The experts could not agree on which alternatives were good (no "gold standard"). The assumptions of decision analysis appear to be violated when (a) there is not a small finite set of mutually exclusive alternatives; (b) the merit of an intervention cannot be agreed on; or (c) the link between intervention and outcome is unclear. Not only nursing but other process-oriented areas of medical care as well may not fit the decision analysis model.

Choice Behavior↗
PubMed1989

[Biotransformation of B 24/76 in the rat, minipig, dog and man].

After oral administration of B 24/76 (1) on experimental animals (rat, minipig, dog) and human beings 11 metabolites could be isolated from urine, faeces and bile. The structure of 7 compounds was elucidated by means of TLC and MS. The investigated species are showing an analogues metabolic pattern with differences in the intensity and main metabolites. In phase II-reaction we could observe qualitative differences.

Adrenergic beta-Antagonists↗
PubMed1989

Smoking--the effects on cerebral vascular circulation. A variable in patient decision making.

Stroke, caused by either infartion or subarachnoid haemorrhage, can have devastating and debilitating effect on its victims. Traditional therapy has focused on the risk factors of hypertension, hyperlipidemia, atherosclerotic heart disease and diabetes milletus. More recently, the literature has focused on smoking and the short and long term effects of cerebral blood flow. The purpose of this paper will be to review the most recent research literature on both the chronic and acute effects of smoking on the cerebral vascular system. More specifically, there will be an examination of the effect of smoking on the outcome of a carotid endarterectomy, subarachnoid haemorrhage and the progression of atherosclerosis. Smoking is harmful and its cumulative effects, along with additive effects must be recognized. Despite increased risk, people continue to smoke affecting disease progression and treatment. Two models will be discussed--the health belief model and the health decision model. These models can provide a basis for nursing to develop and assess comprehensive smoking cessation programmes.

Carotid Artery Diseases↗
PubMed1988

Potassium channels expressed from rat brain cDNA have delayed rectifier properties.

Injection into Xenopus oocytes of RNA synthesized in vitro using the rat brain cDNA RCK1 as a template or nuclear injection of the cDNA results in the expression of functional potassium channels. These channels exhibit properties similar to those of the non-inactivating delayed rectifier channel found in mammalian neurons and other excitable cells.

4-Aminopyridine↗
PubMed1988

Shaker encodes a family of putative potassium channel proteins in the nervous system of Drosophila.

The Shaker locus of Drosophila contains a very large transcription unit. It is expressed predominantly in the nervous system by multiple, differential as well as alternative, splicing mechanisms into different, but functionally related proteins. The structure of the Shaker transcription unit and the properties of the encoded Shaker protein family provide a molecular basis for A channel diversity in excitable cells.

Amino Acid Sequence↗
PubMed1988

Structure of the voltage-dependent potassium channel is highly conserved from Drosophila to vertebrate central nervous systems.

Voltage-sensitive potassium channels are found in vertebrate and invertebrate central nervous systems. We have isolated a rat brain cDNA by cross-hybridization with a probe of the Drosophila Shaker gene complex. Structural conservation of domains of the deduced protein indicate that the rat brain cDNA encodes a voltage-sensitive potassium channel. Of the deduced amino acid sequence, 82% is homologous to the Drosophila Shaker protein indicating that voltage-sensitive potassium channels have been highly conserved during evolution. Selective pressure was highest on sequences facing the intracellular side and on proposed transmembrane segments S4-S6, suggesting that these domains are crucial for voltage-dependent potassium channel function. The corresponding rat mRNA apparently belongs to a family of mRNA molecules which are preferentially expressed in the central nervous system.

Amino Acid Sequence↗
PubMed1987

Molecular organization of the maternal effect region of the Shaker complex of Drosophila: characterization of an I(A) channel transcript with homology to vertebrate Na channel.

We have cloned 215-kb DNA containing the maternal effect region (ME) of the Shaker gene complex (shC) at 16F of the Drosophila X chromosome. Five translocation and deletion breakpoints have been mapped on the cloned DNA allowing a correlation of the genetic map to transcription units. The ME region spans 100 kb. The genetic behavior of this region correlates with the occurrence of maternal RNAs in this part of the ShC. Two transcripts have been identified in the vicinity of chromosomal rearrangements which cause a Sh phenotype. These are a 4.5-kb transcript interrupted by T(x;2)B27 and a 2-kb transcript interrupted by T(X;3)Sh and T(X;Y)W32. The latter transcript is derived from a primary transcript which spans >65 kb genomic DNA. The cDNA-sequencing data show that this Shaker (I(A)channel) gene can encode a protein of 35 kd with three alpha-helical membrane-spanning sequences near its carboxyl terminus. These have a striking homology with membrane-spanning sequences of the vertabrate Na channel.

Journal Article↗
PubMed1982

Nursing decision making in critical care areas.

This exploratory study sought to identify factors that critical care nurses consider relevant in making rapid patient care decisions; to explore the decision making of these nurses in crisis situations; and to identify critical patient care situations where rapid nursing decisions are made. The convenience sample consisted of 50 nurses in critical care settings. A semi-structured interview with a critical care case study was utilized to examine the nurses' decision making. Open ended responses were transformed into fixed categories for tabulation. The findings suggested that: 1 knowledge and experience were the most important factors influencing rapid decision making; 2 although the nurses identified the appropriate decisions in a given crisis situation they had difficulty providing a theoretical rationale for their decisions; 3 the given case study and the 50 crisis situations identified by the subjects indicated that many nursing decisions for critically ill patients were carried out prior to physician assistance. A demographic data questionnaire that examined age, nursing experience, formal education and continuing education of the subjects determined that the majority of the nurses were under 30 years old, had either less than 1 year experience or 7-9 years in critical care, were graduates of a 2-year diploma programme, and took continuing education courses at the community college level.

Adult↗