Design of the mammalian respiratory system. IV Morphometric estimation of pulmonary diffusing capacity; critical evaluation of new sampling method.

The quality of morphometric data obtained by stereological methods depends on the sampling scheme adopted. In the light of recent advances in sampling theory for stereology a sampling strategy has been developed which differs significantly from that used in previous studies. It operates with a cascade of four sampling levels and adopts the principle of A-weighted sampling, a method that should eliminate bias and possibly yield smaller variances. This method is described and discussed in detail. When compared with the old simpler sampling approach it is found that the new method (1) is at least as efficient and (2) that the estimates of morphometric parameters obtained by this method are similar to the data generated by the old method.

[Histologic investigations of PTFE-surface acting for direct tissue contact on implants (author's transl)]. / Histologische Untersuchung eines PTFE-Oberflächenbelages zur Erreichung eines direkten Gewebskontaktes am Implantat.

Generally, implants give rise to toxic reactions and favour the formation and propagation of local infections. Adherance of the soft tissue to the implant prevents the development of fluid filled cavities, thus being of particular interest as a prophylactic measure in arresting spread of infections. Teflon cylinders with an etched surface have been investigated by optical and electron microskopic means following subcutane implantation in mice. We were able to demonstrate closed tissue contact. Signs of toxic tissue reactions were completely absent.