Biomedical subjects

A Rückert

Publications and source records attributed to A Rückert.

12 recordsLinked to original sources

PubMed2001

Sequencing, high-level expression and phylogeny of the pyrophosphate-dependent phosphofructokinase from the thermophilic spirochete Spirochaeta thermophila.

The full-length gene encoding a 554-amino-acid, active pyrophosphate-dependent phosphofructokinase from Spirochaeta thermophila was cloned and sequenced using a combination of degenerate and inverse PCR, and the enzyme expressed to a high level in Escherichia coli. The recombinant enzyme, with a calculated molecular mass of 61 kDa, was purified to near homogeneity and found to be similar to the purified native enzyme for most properties examined. Phylogenetic analysis demonstrated a close relationship between the thermophilic S. thermophila phosphofructokinase and the large beta-subunits of the phosphofructokinases from Borrelia burgdorferi and Treponema pallidum.

Amino Acid Sequence↗

PubMed1998

Early magnetic resonance imaging of brainstem lesions after severe head injury.

OBJECT: The availability of magnetic resonance (MR) imaging data obtained in comatose patients after head injury is scarce, because MR imaging is somewhat cumbersome to perform in patients requiring ventilation and because, in the first hours after injury, its relevance is clearly inferior to computerized tomography (CT) scanning. The authors assessed the value of MR imaging in the early postinjury period. METHODS: In this prospective study MR imaging was performed in 61 consecutive patients within 7 days after they suffered a severe head injury. An initial CT scan had already been obtained. To understand the clinical significance of the lesions whose morphological appearance was identified with MR imaging, brainstem function was assessed by registration of somatosensory and auditory evoked potentials. Brainstem lesions were visualized in 39 patients (64%). Bilateral pontine lesions proved to be 100% fatal and nonbrainstem lesions carried a mortality rate of 9%. In singular cases circumstances allowed for a clear clinical distinction between primary and secondary brainstem lesions. On MR imaging all lesions were hyper- and hypointense after intervals longer than 2 days. Within shorter intervals (< 2 days) after the injury, primary lesions appeared isointense on MR imaging. In one secondary brainstem lesion there were no traces of blood. CONCLUSIONS: Because mean intracranial pressure (ICP) levels in patients without brainstem lesions were similar to those in patients with brainstem lesions, the authors conclude that it was not mainly increased ICP that accounted for the high mortality rates in patients with brainstem lesions. The authors also conclude that brainstem lesions are more frequently found in severe head injury than previously reported in studies based on neuropathological or CT scanning data. Early MR imaging after head injury has a higher predictive value than CT scanning.

Adult↗

PubMed1995

Influence of starch fermentation on bile acid metabolism by colonic bacteria.

Secondary bile acids (BA) may be involved in the pathogenesis of colorectal cancer. In vivo, starch malabsorption has been shown to reduce fecal excretion of secondary BA. The present in vitro study was performed to investigate the effect of starch fermentation on BA metabolism by colonic bacteria. Fecal samples of healthy volunteers were incubated in anaerobic batch cultures for 48 hours with the primary bile acids cholic (0.6 g/l) and chenodeoxycholic acid (0.4 g/l). Media were starch free or enriched with starch (10 g/l). The pH was controlled and held at 6 or 7. In the starch-free incubations, secondary BA were rapidly formed, and degradation of primary to secondary BA was complete within 24 hours. The formation of secondary BA was partially inhibited by the addition of starch to the media. This effect was stronger at pH 6 than at pH 7. Starch was rapidly and completely fermented. In conclusion, this study showed that formation of secondary BA by fecal bacteria is inhibited when starch is simultaneously fermented, an effect that is mainly, but not completely, explained by reduction of pH.

Bacteria, Anaerobic↗

PubMed1992

Ergonomic research study on aircraft luggage handling.

In this study, the lifting and carrying of freight and luggage at a large German airport is classified by typical conditions of performance. These manual load handling tasks take place in height-restricted workplaces. Different methods for an ergonomic evaluation of these tasks are used. The results of the epidemiological, physiological, and biomechanical studies indicated a strain bottleneck during loading tasks in aircraft holds. Therefore, an additional laboratory study was done, in order to analyse the influence of work weight and weight of work object on heart rate, subjective RPE, and number of work objects handled. As a result of the study, the airport has developed a special lifting and carrying training for the aircraft handlers which aims to reduce strain on the postural and locomotor apparatus by an appropriate technique of work. The training programme consists of theoretical instruction by a company doctor and practical exercises under the supervision of a specially-trained sports teacher.

Accidents, Occupational↗

PubMed1990

Ergonomic evaluation of a wheelchair for transfer of disabled passengers at a large airport.

Transferring disabled passengers to the aircraft, both arriving and departing, is one passenger service at a big airport. We use different ergonomic research methods (registration of heart rate, AET job analysis as well as a standardized questionnaire) to evaluate the present wheelchair design. Due to e.g. the high wheelchair backrest, the forces needed to handle the chair and other facts, the current wheelchair causes a strain bottleneck. The results of the AET analysis and the rating of the perceived exertion confirm this finding. A redesigned wheelchair based on ergonomic principles, which reduces stress on the employees and offers more comfort to disabled passengers, is presented.

Aviation↗

PubMed1969