Orientation of Giemsa C-bands in interphase cells of Allium cepa L.

Summary Orientation of Giemsa C-bands in Allium cepa was studied in both mitotic and interphase cells. It has been shown that telophase orientation of the chromosome is maintained throughout the interphase and early prophase. It has been assumed that this non-random orientation is due to anchorage of the telomeres with the nuclear membrane. Contrary to earlier observations, 2 by 2 pairing of the telomeres could not be traced in this species.     

delta-9-Tetrahydrocannabinol (THC) inhibition of the membrane transport system for thymidine]

THC decreases 3H-thymidine uptake within 15 sec. after addition of the drug to the culture (L1210 murine lymphoma cells and human lymphocytes). Experiments performed at 0 degrees C indicate that THC has no action on thymidine binding to the carrier. THC in micromolar concentration inhibits DNA synthesis through a alteration of membrane configuration.     

Diurnal variations in cholinesterase activities in the slug,Laevicaulis alte

Summary Cyclical variations in acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) levels in foot muscle (FM) and AChE activity in central nervous system (CNS) ofLaevicaulis, during 24-h-day, were maximal at 04.00 h and minimal at 12.00 h. But BuChE activity was 180°C out of phase with AChE in CNS. The rhythmic trend of AChE in CNS might be due to true cholinesterase activity.Acknowledgements. The Senior Fellowship (CSIR) awarded to TPK is thankfully acknowledged.     

Cross-linked arabinogalactan: A new affinity matrix for the purification ofRicinus communis lectins

Summary Arabinogalactan has been cross-linked to give a new high capacity affinity matrix for the purification ofRicinus communis lectins. It shows a capacity which is 50 times greater than that of the conventional affinity matrices.     

Long-term depression of two primary immune responses induced by a single dose of 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide (DTIC)

Summary 2 primary immune responses (anti-SRBC antibody response and allograft rejection) have been tested in mice at various time intervals after single doses of either DTIC or cyclophosphamide. The DTIC-induced immunodepression proved to be extremely long-lasting, being still detectable after 2 months.This work was supported by Project NO1-CB 64054 of the U.S.-Italy Cooperative Science Program.