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We enumerate rooted 2-connected and 3-connected surface maps with respect to vertices and edges. We also derive the bivariate version of the large face-width result for random 3-connected maps. These results are then used to derive asymptotic formulas for the number of labelled graphs of genus g (1-connected, 2-connected, and 3-connected graphs.), Comment: 28 pages; corrected, clarified & simplified presentation

Zum Knochenersatz im Kieferbereich stehen prothetische und alloplastische Ersatzmaterialien und vor allem Knochen zur Verfugung (Lentrodt 1988). Neben dem bevorzugten autogenen Knochen kann bei bestimmten Indikationen auch allogenes Knochenmaterial verwendet werden (Farmand 1990; Kubier et al. 1991). Von Mittelmeier u. Katthagen (1984) wurde ein durch Pyrolisierung und Sinterung gewonnenes xenogenes Knochenersatzmaterial bovinen Ursprungs (Pyrost) vorgestellt. Mittelmeier u. Mittelmeier (1988) berichteten uber die erfolgreiche Anwendung von Pyrost zum Knochenersatz im ersatzstarken Lager und von der Kombination aus Pyrost mit autogenem Knochenmark unter ersatzschwachen Lagerbedingungen.

The ability of contrast echocardiography to assess regional myocardial perfusion during cardiopulmonary bypass in a dog model for coronary artery bypass surgery was evaluated. Sonicated Renograffin-76 microbubbles (meglumin diatrigoate and sodium diatrigoate) were injected into an aortic root proximal to an aortic occlusion clamp root while dogs were on cardiopulmonary bypass, with the heart arrested in diastole. Echocardiographic contrast-enhanced regions of myocardial perfusion were easily visualized. Differences in contrast-enhanced myocardial regions depended on coronary artery occlusion or patency. The contrast-enhanced images of myocardial perfusion showed that, for a given myocardial segment of the supplying vessel, the presence or absence of contrast effect reliably predicted vessel occlusion or patency (P less than .01). In the future contrast echocardiography may allow the direct assessment of regional myocardial perfusion in the operating room.

DNA isolated from skin epitheliomas containing papovavirus induced lymphomas within four to eight weeks in 40 to 50 per cent of newborn Syrian hamsters injected. This DNA effect was eliminated by DNase but not by RNase and was not induced by DNA preparations of transplanted epitheliomas or the induced lymphomas. Lymphomas were similarly induced by cellfree filtrates from certain human tumors such as gastric carcinomas and ovarian tumors. Little or no lymphoma effects were observed following injections with filtrates derived from normal human or animal tissues or human blood. The lymphomas induced by DNA and human tumors were transmissible by cell-free filtrates to newborn Syrian hamsters; however, successful serial passage, like the primary lymphomas induced by the DNA preparations, depended upon the use of a newborn hamster from a special breeding colony of hamsters.

The protein pattern of a type-D retrovirus (PMFV) isolated from and propagated in human cell lines has been investigated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Staining with Coomassie blue and labeling with 14C-leucine/14C-lysine revealed five viral polypeptides with molecular weights of 10,000, 12,000, 15,000, 25,000, and 68,000. The 68,000 D-protein was shown to be a glycoprotein by incorporation of 3H-glucosamine and the 15,000 D-protein was identified as a phosphoprotein. By comparing PMFV with the closely related Mason-Pfizer monkey virus (MPMV) in co-electrophoresis experiments no clear difference was detected in viral 14C-leucine/14C-lysine profiles. The viruses differ, however, with respect to their glycoprotein patterns. A glycoprotein corresponding to the gp20 of MPMV has not been detected in PMFV irrespective of the cell line used for propagation of viruses.

Images Figs. 12-14 Figs. 1-2 Figs. 3-8 Figs. 9-11