Scanning-autoradiography—a new method for the demonstration of membrane-surface-associated structures

Summary A method for the demonstration of membrane-localized markers and receptors is described which results from the combination of autoradiography and scanning electronmicroscopy.     

Experimental production of local osteomalacia

Summary The newly deposited bone which was laid down on necrotic bone in the experimentally produced osteochondral chips in the knee joint of 16 sheep and rabbits remained unmineralized and undermineralized in which respect it resembled osteomalatic bone. Local factors which interfere with the mineralisation of a new covering bone should be considered in the pathogenesis of osteomalacia, in healing of aseptic bone necrosis and fractures, and incorporation and fate of bone transplants.This project was partly supported by the Action Research for the Crippled Child, grant No. A/8/877.     

Nuclear degeneration induced by chlortetracycline

Summary After application of chlortetracycline to plants, a degeneration of nuclei, manifested by dilatation and vacuolation of the nuclear membrane, occurs in the mesophyll cells of the sunflower plant.     

Induction of lymphomas by urethane in combination with diethylstilboestrol in CFLP mice

Summary The combination of urethane and the non-steroidal oestrogen diethylstilboestrol induced lymphomas in CFLP mice.This work was supported by grants from the Ministry of Health of Hungary (Grants No. 2-10-0401-01-2/K, 2-11-0801-01-1/VR, 2-09-0801-01-1/E).     

Effects of calcium-EGTA buffers on active calcium transport in inside-out red cell membrane vesicles

Summary In inside-out red cell membrane vesicles, the free calcium concentration half-maximally stimulating active calcium uptake is about 2 orders of magnitude smaller in a calcium-EGTA buffer than in media containing unbuffered calcium. In calcium-EGTA buffer, the maximum rate of calcium uptake is determined by the total calcium concentration present. A possible model for explaining these findings is presented.Acknowledgments. This work was supported by the Scientific Research Council, Ministry of Health, Hungary (6-03-0306-01-1/Gá). We thank for the valuable comments of Dr Ilma Szász and for the skilful technical assistance of Mrs M. Sarkadi.     

The use of dipeptide-p-nitranilides for the study of aminopeptidase specificity

Summary The use of dipeptide-p-nitranilides for the study of 2 placental aminopeptidases separated on Sephadex G200 helped in establishing some regular features of their specifities. The high-molecular (320,000 daltons) one prefers Phe in position P'₁ to Leu, whereas the lower-molecular aminopeptidase (145,000 daltons) prefers Leu. The high-molecular aminopeptidase splits very slowly the N-terminal Leu when Gly is in adjacent position. Leu-Gly-p-NA is therefore an inhibitor of this AP.     

On some potassium-like qualities of the thallium ion

Zusammenfassung Thallium ist am isolierten Forschherz und M. rectus abdominis von kaliumähnlicher Wirkung. Es setzt das mit kaliumfreier Lösung in Stillstand gebrachte Froschherz in Bewegung, bei erhöhter Konzentration führt es zum Herzstillstand. Am rectus-Muskel verursacht Thallium eine Kontraktur. Seine Aktivität am Froschherz übertrifft jene von Kalium, während am isolierten rectus-Muskel ihre Aktivität gleichwertig ist.