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Biomedical subjects

A Spiegelberg

Publications and source records attributed to A Spiegelberg.

10 recordsLinked to original sources
PubMed2002

Genetically modified maize and soybean on the Egyptian food market.

The results of a survey study on food samples produced from genetically modified soybean and maize collected from the Egyptian market are presented. Forty samples of soybean and 40 samples of maize products have been gathered randomly from markets in Cairo and Giza. The genetic modification was detected by polymerase chain reaction (PCR) using official detection methods according to section 35 of the German Foodstuffs Act. Samples were investigated for the presence of material derived from the following genetically modified organisms (GMOs) all of which are approved for food use in Europe: Roundup Ready soybean (RRS) and maize lines Bt176, Bt11, T25 and MON810. In addition, samples were examined in qualitative and quantitative analysis for the presence of material derived from the transgenic maize line StarLink (Aventis) which was approved for animal feed use exclusively in the US. Twenty % of 40 investigated soy samples contained Roundup Ready soybean; 15% of 40 maize samples tested positive for Bt176 and 12.5% positive for Bt11 maize. Furthermore, the presence of StarLink maize could clearly be demonstrated in four samples mixed with Bt176 and Bt11. The percentage of StarLink was less than 1% in quantitative analysis. The maize lines T25 and MON810 were not detected.

DNA, Plant↗
PubMed1999

A comparative study of the Spiegelberg compliance device with a manual volume-injection method: a clinical evaluation in patients with hydrocephalus.

A new automated method of compliance measurement has been developed which may overcome some of the problems of the manual method. Measurement of craniospinal compliance in brain-injured patients offers the potential for early detection of raised intracranial pressure (ICP) before it rises to levels that may damage brain parenchyma. However, limitations of the existing manual volume pressure techniques have meant few centres routinely perform compliance testing. We report on the results of testing this new method against a manual volume pressure response method (VPR) in 10 patients with hydrocephalus. In this comparison study, 19 pairs of compliance measurements were obtained from 10 patients. The compliance values obtained ranged from 0.141 to 1.407 ml/mmHg. There was a good correlation between the two methods (r2 = 0.8508). The average bias in compliance between the two methods was 0.111 ml/mmHg (95% CL for the bias = 0.0438, 0.1788) with the new method reading higher compliance than the manual method. These results indicate that the new automatic method of compliance measurement correlates well with an independent and classical measurement of compliance, and defines the bias and limits of agreement by which the new method measures craniospinal compliance in patients with hydrocephalus. Further work is needed to validate this device over a wider compliance range, especially at the lower compliance range often found in head injured patients. Studies are also required to determine the normal range of compliance values in the patient populations who undergo ICP monitoring. Research into determining which patient populations may benefit from continuous compliance measurement is warranted.

Brain Injuries↗
PubMed1993

[Identification of irradiated pasteurized egg products: a combined method for use in routine control].

Pasteurized egg products (whole egg, egg yolk and egg white) were tested for irradiation treatment in the German food control laboratories in Oldenburg/Niedersachsen and Kassel/Hessen as well as in the food irradiation laboratory of the German federal health office. Gas chromatographic/mass spectrometric measurements on the fat components of egg-products showed clearly whether the product had been irradiated or not. While in unirradiated samples no traces of special hydrocarbons (according to the fatty acid composition of egg) and no traces of the irradiation-specific compound 2-Dodecyl-cyclobutanone were found, irradiated control samples as well as products of two Belgian suppliers contained these substances. Additionally, regarding the rather high time consumption of gas chromatography, electron spin resonance (ESR)-measurements were carried out on the packaging material of egg products. Irradiated packaging material (cellulose) could be easily detected by the appearance of a signal pair in the ESR spectrum (cellulose radical). ESR measurements are very fast and easy to perform so that this method can be used for screening. Microbiological investigations showed remarkably reduced total numbers of microorganisms for some irradiated samples, but the microbiological status is influenced by other factors like storage-time and -temperature, so that microbiological tests can not be used successfully for screening on irradiation treatment.

Animals↗
PubMed1990

Assessment of electrophoretic mobility changes of human erythrocytes by free flow electrophoresis after in vitro and in vivo irradiation.

Single cell measurements of electrophoretic mobility showed a linear dose-response of human erythrocytes after exposure to ionizing radiation. To establish a biological indicator- or dosimeter-system for application to dose-estimations after accidental exposures, we tried to measure dose dependent EPM-changes by the free flow electrophoresis technique, a rapid and efficient method which supplies the capacity needed for application. The in vitro irradiated erythrocytes of most donors showed an oscillating dose-response but erythrocytes from several other individuals in a contradictory manner whereby the EPM of erythrocytes from radiotherapy patients increased linearly with the amount of administered dose. However, the wide interindividual EPM-range of unirradiated erythrocytes inhibits the application of this technique in biological dosimetry.

Dose-Response Relationship, Radiation↗
PubMed1989

Changes in oligosaccharides of human blood cells measured by tritium- and FITC-labeled lectins after in vitro- and in vivo-irradiation--lectin binding as a 'biological dosemeter'?

The lectin-binding system has been described previously as a biological dosimeter, by revealing induced changes in oligosaccharides of the cell membrane. The measurements were performed by binding [3H]concanavalin A to blood cells. Our results on human blood cells irradiated in vitro with doses in the range 0.5-5 Gy indicate great difficulties in using radioactive labeled Con-A for an accurate quantitative analysis of radiation effects on cell membranes. It appears nearly impossible to differentiate between only a few damaged cells and the remaining undamaged cells. Using fluorescein-labeled Con-A and wheat germ agglutinin, single-cell measurements of fluorescence intensity by flow cytometry revealed enhanced lectin-binding to platelets, lymphocytes and monocytes in the dose range 0.5-5 Gy after in vitro irradiation. But even by this method it was impossible to discriminate irradiations in either partial or whole-body irradiated patients. There were no significant or reproducible changes in the binding capacities of the blood-cell membranes of these patients. Therefore, the suitability of lectin binding as a 'biological indicator' for irradiation could not be confirmed.

Adult↗
PubMed1979

[X-linked night-blindness: clinical and electrophysiological investigations including de-ERG in two families (author's transl)].

Patients from two families with X-linked recessive nyctalopia and myopia were investigated. The functional tests included clinical examinations (visual acuity, color sense, visual fields, dark adaptation) and electrophysiological examinations (ac coupled ERG, dc-coupled ERG, EOG). The dc-coupled ERG registrations were done without general anesthesia. In one case, a comparison with results obtained in 1967 was possible. There was no evidence of increase in functional impairment. On the basis of the electrophysiological results, the nature and localization of the defect causing nyctalopia are discussed. The postreceptoral retinal structures appear not to be involved exclusively.

Adult↗
PubMedDate not supplied

Ovalis TAH: development and in vitro testing of a new electromechanical energy converter for a total artificial heart.

A new electromechanical energy converting system has been developed to yield an efficient and durable orthotopic total artificial heart (TAH). The energy converter we developed transforms the unidirectional rotational motion of the motor into a longitudinal forward-reverse movement of an internal geared oval, linked directly to pusher plates on both sides. To ensure a permanent positive connection between the drive gear and the internally geared wheel, a ball bearing runs inside an oval shaped guide track. Motor, gear unit, and conical pusher plates are seated between alternately ejecting and filling ventricles. The unidirectional motion of the brushless DC motor affords easier motor control, reduces energy demand, and ensures longer life of the motor when compared with a bidirectional motion system. In vitro testing has been performed on a mock circulation loop. The overall system efficiency of the TAH Ovalis was 27-39% (mean, 36%) for the pump output range of 2-7 L/min. The maximum output of 7 L/min can be obtained with a pump rate of 130 min(-1) and an afterload pressure of 140 mm Hg. For an average sized human with a mean cardiac output of 6 L/min at a mean aortic pressure of 120 mm Hg, 5 watts of input power would be required. The size of the prototype is 560 cm3, the weight is 950 g. Our first in vitro studies demonstrated the excellent efficiency and pump performance of this new electromechanical energy converter. The results prove the feasibility of this new concept's use as an energy converter for a total artificial heart.

Biomechanical Phenomena↗
PubMedDate not supplied

Evaluation of a gas chromatographic method to identify irradiated chicken, pork, and beef by detection of volatile hydrocarbons.

A method suitable for routine application was used in an interlaboratory study to detect irradiation treatment of chicken carcass, pork, and beef. By using gas chromatographic analysis, 17 participating laboratories determined the quantity of 4 different radiation-induced volatile hydrocarbons (tetradecene, pentadecane, hexadecadiene, and heptadecene) in the fat fraction of coded specimens approximately 3 and 6 months after irradiation. The specimens of each type of meat were supplied by 2 different producers. The dose range tested (0.6-7.5 kGy) included levels commercially used to reduce the number of contaminating microorganisms (1-5 kGy). The method employed permitted a correct identification of irradiated or nonirradiated in 98.3% of the 864 specimens.

Animals↗