Biomedical subjects
Publications and source records attributed to U Schramm.
The excretory system of Habrotrocha rosa consists of two protonephridia. From each of them seven tubules lead to a terminal organ, also called cyrtocyte. Its weir basket contains structures which resemble ciliary rootlets. The lumen of the excretory system is bordered by a syncytial layer of cytoplasm. Cells are only found in the upper region of the trunk, where the channel is twisted several times.
The alimentary system of Habrotrocha rosa is composed of the alimentary channel, five digestive glands and another gland which is in close relation to the intestinal syncytium. After the present investigation, the alimentary channel can be divided into sections which clearly differ from each other, these are: oral cavity, pharynx, oesophagus, mastax, stomach-hose, syncytium of intestine, and terminal intestine.
The integument of the rotifer Habrotrocha rosa Donner is provided with pores and formed by an extrasyncytial cuticle and a syncytial hypodermis. This hypodermis peripherally contains 3 layers of dense cytoplasm and borders the cuticle by an asymmetric cell membrane. The wall of the pores is stiffened proximally like an annulus. The pores lead into cytoplasmic invaginations which are surrounded by vesicles. Close to and also beneath the condensed cytoplasmic layers microbodies are found, which are interpreted as microperoxisomes. Subhypodermal layers of muscles are connected with the cytoplasm of the hypodermis by desmosome-like structures.
Three species of rotifers were fixed with glutaraldehyde and postfixed in a OsO4-ferricyanide solution. This procedure results in staining of the sarcoplasmic reticulum (SR) and the surface coat of muscle cells as well as in staining of the surface coat of glands and nerve cells. Section-staining with leadcitrate increased the electron opacity of the precipitates, which are interpreted as polysaccharides. The partial decrease of staining of polysaccharides, which sometimes is observed, may be related to processes of function. The precipitates within the SR are considered as glycogen-beta-particles.
Experiments carried out with cadaver cartilage from the tibiaplateau were performed using an excimer-laser to demonstrate its use for cartilage removal. Laser applications resulted in a cartilage ablation depending on energy density and the number of applied pulses. Observations made using scanning electron-microscopy showed the influence of the pulse rate on the surface structure. Transmission-electron-microscopical investigation showed the existence of a superficially altered layer with a depth of approx. 6 microns. On the basis of the results obtained, the conclusion can be reached that application of excimer-lasers for cartilage removal in a view of future endoscopic surgery could become a valuable alternative to the existing methods in the therapy of osteoarthritis.