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C Grosse-Siestrup

Publications and source records attributed to C Grosse-Siestrup.

35 records · Page 2Linked to original sources
PubMed1984

Design criteria for percutaneous devices.

A theoretical model of a percutaneous device is described. The model is split into several components, each with its own function. Special structures such as horns, hair, feathers, fingernails, hoofs , teeth, and antlers are taken as examples where nature has solved the problems of "percutaneous devices." These structures have been regarded in relation to dimensional and structural differences of epidermis, dermis, and subcutis. Theoretical guidelines are described for the design of a prosthetic percutaneous device.

Animals↗
PubMed1980

[Chronobiological aspects of artificial total heart replacement in long-term animal experiments--a systemanalytic study (author's transl)].

Biological rhythms (circadian rhythms) have been observed in the hemodynamics of experimental animals (calves). After artificial total heart replacement these rhythms are typically altered compared to control animals. These observations induce a growing consideration of chronobiological aspects in a systemanalysis for the conception of an automatic external control of the artificial heart, which has to be divided in:--parameter-progression (tendencies), --parameter-variation (discrete, oscillations), --parameter-coupling (phase shifts).

Animals↗
PubMed1979

Arterio-venous shunt with percutaneous leads in calves for long-term in vivo testing of blood-contact materials.

In six calves an extracorporeal arteriovenous shunt in combination with a successful type of percutaneous lead has been implanted. Flow chambers with various test materials can be inserted. Preliminary results show that this shunt can be used for long term tests for evaluation of blood contact material and studies about thrombus formation in an ex vivo setting as well as for permanent blood access for the purpose of various measurements, drug application and for hemodialysis.

Animals↗
PubMed1978

[Stable postoperative phase after total artificial heart-replacement in animal-experiments (author's transl)].

Presented are results of an analysis of more than 30000 data which were sampled in seven long-surviving calves after total artificial heart-replacement (more than 35 days survival). The continuity of 24 types of data (hemodynamic, labor- and physical data) are transformed for every animal in time-equidistant datafields and after this an average continuity for all seven animals is calculated and plotted. Twenty days after the operation the data have reached the preoperative values in nearly all cases, indicating a stable phase starting, according to the clinical condition of the animals.

Animals↗
PubMed1976

[Observation in 10 calves with a survival time of more than 100 hours after total heart replacement (author's transl)].

It is reported on 10 calves surviving total artificial heart replacement more than 100 hours. Pneumatically driven double-chambered blood pumps made of silastic were implanted. During the experiments an increase of the right atrial pressure as well as a rise of the perfusion volumes (CO) and of the blood volumes could be found regularly. At autopsy congestion of the organs especially of the liver was a regular finding. The changed hemodynamic is first seen as possible reason for this developments. The influence of anemia and the possible disturbances in the neurohumoral autoregulation of the animals by unphysiologic pressure curves are discussed.

Animals↗
PubMedDate not supplied

The isolated perfused liver. a new model using autologous blood and porcine slaughterhouse organs.

INTRODUCTION: Current models of isolated and perfused livers are limited by nonphysiologic perfusates or the need for the use of high numbers of laboratory animals. The present study was performed in order to rectify these difficulties. METHODS: To establish a new isolated perfused liver model, a perfusion circuit was developed using normothermic, autologous hemoperfusion and organs obtained from a slaughterhouse. RESULTS: Stable organ function was maintained over 220 min. The organs displayed physiologic values for measured variables, including oxygen consumption which varied from 5.2+/-1.5 ml/min at 40 min to 5.2+/-2.4 ml/min at 220 min, and bile production (0.15-0.31 ml/min, respectively). DISCUSSION: The present studies demonstrate a new approach for experimental liver perfusion by combining the optimal perfusion medium of autologous blood and slaughterhouse organs as source material.

Alanine Transaminase↗