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Biomedical subjects

H Heide

Publications and source records attributed to H Heide.

8 recordsLinked to original sources
PubMed1983

[Contribution to the parasitic fauna of the GDR (German Democratic Republic). 7. Occurrence of Gasterophilus larvae (Diptera: Gasterophilidae) in horses].

Observations were carried out from May 1977 to May 1980 on occurrence, fauna, and seasonal dynamics of Gasterophilus spp. in 2,539 horses for butchering from all districts of the German Democratic Republic and also in 79 horses after control against gasterophilosis. 99.98% of the 13,742 second and third instar larvae of horses for butchering were Gasterophilus intestinalis, only 0.02% Gasterophilus nasalis. Out of 7,765 larvae passed after control measures Gasterophilus intestinalis dominated with more than 96%. Only in four districts of the German Democratic Republic Gasterophilus nasalis was found. The mean extensive invasion from 1977 to 1980 was 8.7%, the mean intensive invasion 33.4 +/- 3.16 larvae/infected horse, the number of larvae ranging between 2 and 576 per horse. From 1977/78 to 1979/80 the intensive invasion increased from 25.8 +/- 2.74 to 58.6 +/- 3.49 larvae/infected horse. Peaks of extensive invasion appeared in April, May and October. From October to February the horses harboured both second and third instar larvae of Gasterophilus spp. The occurrence of gasterophilosis is concentrated in the northern parts of the German Democratic Republic.

Animals↗
PubMed1979

[Experimental application of calcium phosphate granulate for the substitution of conventional bone transplants (author's transl)].

Autologous spongiosa, a calcium phosphate ceramic and Kiel bone chips were implanted in the tibiae of dogs and compared with respect to tissue compatibility and osteogenetic effect. After the ceramic implants and the autologous spongiosa had been left in the tibial fat marrow for six weeks, bone tissue and bone marrow had formed to the same extent around both materials. Their stimulating effect on osteogenesis was comparable. In contrast to the ceramic material, together with which they had been implanted in active bone marrow, the Kiel bone chips were surrounded by fibrous tissue in addition to bone tissue. All of the three types of implant proved to be tissue compatible. On the whole, the calcium phosphate ceramic was found to be equal to autologous and superior to heterologous spongiosa from a biological point of view. In technical terms the ceramic implant was superior also to the autologous graft.

Animals↗
PubMed1977

[Resorbable calcium phosphate ceramics under load (author's transl)].

Cylindrical implants with 45% by volume continuous open tubular pores were prepared from ceramic materials based on tricalcium and tetracalcium phosphate and used to replace 7 mm thick bone segments in the tibiae of dogs. The treated limbs of the experimental animals were fixed for 12 weeks, after which time the dogs were allowed to move freely so that the limbs were physiologically loaded. The histological examination showed that primary bone healing had taken place between the bone and the ceramic material. After 10 months the tricalcium-phosphate-based ceramic material was resorbed and replaced by bone tissue to a large extent. The ceramic material on the bases of tetracalcium phosphate on the other hand, had remained completely unchanged, and its pores were filled with lamellar bone tissue which was in direct contact with the implant without connective tissue. The bond between natural bone and implant was mechanically stable. The ceramic materials investigated were found to be tissue-compatible, and in our opinion they can be substituted for part of the bone transplants used today. Considering its varying strength properties, the tricalcium phosphate ceramic material can be used only in cases where no high stress is expected; the tetracalciumphosphate-based ceramic material, however, has a higher mechanical strength and can therefore be used also for larger permanent implants which have to bear high mechanical stress.

Animals↗
PubMed1976

[Experimental bone replacement with resorbable calcium phosphate ceramic (author's transl)].

Compact cylindrical implants (5 x 15.5 mm) of seven calcium phosphate ceramics of different formulations that had been implanted for 6 weeks without fixation in the tibia of dogs were examined histologically. The tissue compatibility of the implant turned out to be dependent on the mineralogical and chemical composition of the material: the ceramic material was biocompatible at a CaO/P2O5 ratio between 2:1 and 4:1, the optimum ratio being about 3:1 (tricalcium phosphate). In addition, cylindrical tetracalcium phosphate implatns with an entirely porous structure were implanted in the same manner. After 6 months, they were resorbed to a minor extent. Implants of different calcium phosphate mixtures, on the other hand, were resorbed to a large extend after the same time. The ceramic material was replaced by mineralised bone tissue which had formed directly on the ceramic implant as well as within the pores. There were no foreign body reactions. Investigations with segment-shaped implants which were implanted in the tibia of dogs and fixed with AO-plates or splints extra-cutaneously for about 8-10 weeks, provided information abouth the maximum stress that can be borne by the implants. While implants with a porosity of 75 percent did not sustain the stress after the fixation had been removed, those with a porosity of 45 percent could be subjected to physiological stress after removal of the splints.

Animals↗