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Biomedical subjects

U Reuter

Publications and source records attributed to U Reuter.

44 records · Page 3Linked to original sources
PubMed1990

[The effect of the oxygen content of the air breathed in on the passive electrical properties of muscle tissue].

Due to a want of oxygen in the breathing air there appears a change of the volume of muscle cells, of ion concentrations inside and outside the cells as well as disturbances the structure and membrane potential. These changes are connected with changes of the passive electrical properties of the muscle tissue. Measuring the electrical impedance of the muscle it is possible to diagnose alterations as shock and disorder of microcirculation in an easy way continuously. Investigations with rats show that a decrease of the oxygen content in the inspiration air effects characteristic changes in muscle impedance. These changes are reversible in normoxia.

Animals↗
PubMed1987

[Transcutaneous and intracutaneous pO2 measurements in the assessment of peripheral arterial occlusive diseases].

The purpose of the study was to compare the results of intra- and transcutaneous pO2-measurements of patients suffering from an arterial occlusive disease of the lower extremities (Fontaine I-IV) with that of 20 healthy volunteers. The measurements were performed by one transcutaneous and two intracutaneous pO2-electrodes on the dorsum of the foot. As reference we used the ratio pf/pft of the venous occlusion plethysmography of the calf. Already at rest the transcutaneous pO2 allows a significant separation of healthy persons and patients of Fontaine II. After a 3-minute ischemic period the greatly changed time parameters 'delay-time', 'half-time of the pO2 increase' as well as the 'pO2 recovery time' permit a significant separation of Fontaine III from healthy persons and Fontaine II. The findings show that both methods complete one another. The value of a local pO2 measurement for an individual therapy control is emphasized.

Arterial Occlusive Diseases↗
PubMed1987

[Modification of fracture healing by ultrasonics in an animal model. 2. Radiologic and histologic results].

Both tibiae were osteotomised and medullary nailing in 40 rabbits. In each case the right fracture was treated with ultrasound of 0.1 W/cm2 for 2 minutes every second day altogether 4 times. The left extremity was used as control. The estimation of the mineralization took place semiquantitatively after weekly radiologic checks, this one of the callus maturation histologically in the decalcified bone. By ultrasound treatment an enlarged callus formation and an accelerated callus maturation was shown in contrast to the untreated extremity. An accelerated three-phasic fracture healing was provable by ultrasound influence. The advantage of the mineralization amounted to 2 weeks in the 4th postoperative week. The ultrasound influence of the fracture healing shows, therefore, as remedy of choice in comparison with other stimulation methods.

Animals↗
PubMed1984

[Modification of bone fracture healing by ultrasound in an animal experiment model].

Both tibiae were osteotomised after medullary nailing in 40 rabbits. In each case the right fracture was treated with ultrasound of 0.1 W/cm2 for 2 minutes 4 times every second day after on week. The left extremity is used as control. An accelerated and increased callus formation and callus maturation were found by ultrasonic therapy. This was possible to be shown on a higher level of the alkaline phosphatase, a higher temperature, and an accelerated calcium and phosphate incorporation in the callus in comparison with the untreated side. The mineralisation by means of ultrasound showed a characteristical three phase behaviour. The mechanism of action is probably the piezo-electric effect of the local tension induction by ultrasound with resultant activation of the metabolism. The advantage of the mineralisation amounted to 2 weeks in contrast to the untreated extremity in the 4th week after the fracture. These findings confirm numerous positive clinical results.

Alkaline Phosphatase↗
PubMed1982

[Intra-extracellular ion changes in heart and skeletal muscle in experimental hemorrhagic shock].

An experimental shock model with rabbits and dogs was used (bleeding to an constant systemic pressure of 5.3-6.6 kPa) to investigate quality and time dependency of intra-extracellular gradients of Na+, K+ and Ca++ in skeletal and heart muscle. We found the ion gradient changes to be earlier and more pronounces in skeletal than in heart muscle, where strongest changes appear within the heart ears and significant smaller ones within ventricular and papillar muscles. Unexpectedly there was in heart and skeletal muscle the same two phasic ionic course, and a close correlation between ion gradient changes and shock duration in skeletal muscle. There is a good agreement between our results and the common clinical observations of ventricular arrhythmia caused by acute hypotonic circulatory situation and therefore the early restoration of the disturbed transcapillary exchange in the peripheral circulation is demanded.

Animals↗
PubMedDate not supplied

Examples of MAK values and carcinogenicity classification for mixtures.

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) generally sets MAK values for single pure substances. MAK values for mixtures are only established after specific toxicological evaluation of the particular mixture. In practice, there are a few cases in which a common MAK value for the sum of all components was set, such as for mixtures of isomers (e.g. xylenes) or mixtures of related compounds (e.g. Kathon), in which the components of the mixture show comparable toxicological effects. For mixtures of isomers with different toxicological potentials, different MAK values for the single isomers are usually established. The only exception is for the isomer mixture of alpha- and beta-hexachlorocyclohexane, for which a mathematically calculated MAK value was proposed. A safe threshold cannot be established for mixtures containing substances with a genotoxic and carcinogenic potential. These mixtures are categorized either according to the proven carcinogenicity of the mixture, such as alpha-chlorinated toluenes, or according to the carcinogenic substances included, as for pyrolysis products such as coal tars.

Animals↗