The nematode Steinernema kraussei (Steiner) was rediscovered in the type locality near Neuenherrsee in Westphalia, Germany. This isolate is morphologically identical with that described in 1923 by Steiner. Steiner's original description is completed by these main characters: the head with two circles of papillae, the labial bearing six and the cephalic four papillae; the excretory pore opening of adults is situated far in front of a nerve ring; the male tail has a fine mucron, spicules are on average 49 pm long in first generation, their manubrium having the ratio length to width 1:1 ; spicule retinaculum is usually well developed, gubcmaculum varies in its shape, but mostly is boat-shaped with hooked proximal part. Infective juveniles are 797 to 1102 pm long and their lateral fields have 8 ridges, but the central pair is less distinct and sometimes tends to merge into one unpaired ridge. Since S. kraussei is the oldest, and now the most completely described nematode species in the genus Steinernema, it has to be considered as the type species of this genus. The living culture is presently maintained in several laboratories and all formerly and future described similar species should be compared with this nematode.
Stem cells biology is one of the most frequent topic of physiological research of today. Spinal fusion represents common bone biology challenge. It is the indicator of osteoinduction and new bone formation on ectopic model. The purpose of this study was to establish a simple model of spinal fusion based on a rat model including verification of the possible use of titanium microplates with hydroxyapatite scaffold combined with human bone marrow-derived mesenchymal stem cells (MSCs). Spinous processes of two adjacent vertebrae were fixed in 15 Wistar rats. The space between bony vertebral arches and spinous processes was either filled with augmentation material only and covered with a resorbable collagen membrane (Group 1), or filled with augmentation material loaded with 5 × 10 6 MSCs and covered with a resorbable collagen membrane (Group 2). The rats were sacrificed 8 weeks after the surgery. Histology, histomorphometry and micro-CT were performed. The new model of interspinous fusion was safe, easy, inexpensive, with zero mortality. We did not detect any substantial pathological changes or tumor formation after graft implantation. We observed a nonsignificant effect on the formation of new bone tissue between Group 1 and Group 2. In the group with MSCs (Group 2) we described mino r inflamatory response which indicates the imunomodulational and antiinflamatory role of MSCs. In conclusion, this new model proved to be easy to use in small animals like rats., K. Klíma, V. Vaněček, A. Kohout, O. Jiroušek, R. Foltán, J. Štulík, V. Machoň, G. Pavlíková, P. Jendelová, E. Syková, J. Šedý., and Obsahuje bibliografii