Influence of Chilling on Electrolyte Permeability, Oxygen Uptake and 2,4-Binitrophenol Stimulated Oxygen Uptake in Leaf Discs of the Thermophilic Cucumis sativus

The effect of chilling was studied in leaf discs from the chilling-sensitive Cucumis sativus L. by measurement of the electrolyte leakage from the discs, by oxygen uptake and by uncoupling of respiration with 2,4 dinitrophenol. Short periods of chilling are characterized by minor significant increases of electrolyte permeability, of respiration and of preserved ability to be uncoupled by 2,4-dinilrophenol. A longer period of chilling resulted in a strongly increased electrolyte permeability, in reduced oxygen uptake and in disappearance of uncoupling by 2,4 dinitrophenol. In general the induced changes in permeability and respiration were reversible within 4 days of chilling, if the discs were placed at 25°C after chilling.     

Electrical pacing in the gastroduodenal junction area of conscious dogs (author's transl)]

To determine whether the electric activities of the stomach and duodenum are related, the gastroduodenal junction area of the stomach of dogs was paced through implanted bipolar silver electrodes. It was found that the pacing rate of the basic electrical rhythm (BER) in the antrum of the stomach could be increased to a maximum of 8.9 cycles/min, without affecting the BER frequency in the duodenum. Conversely when the pacing rate of the BER in the duodenum was increased to a maximum of 24 cycles/min, the BER frequency in the antrum remained unaffected. These results show that the BER in the stomach and duodenum are independent, and imply that the BER cycles in the stomach and duodenum are due to the presence of two independent pace-maker areas.     

Evaluation of nucleotide derivatives and sugar nucleotide analogs as inhibitors of glycosyltransferases.

The inhibition of glycosyltransferases was studied using uridine monophosphate derivatives and uridine diphosphate sugar analogs. Modification in the nucleoside portion caused selective inhibition of glycosyltransferases.     

Targeting of Chrolamphenicol Acetyltransferase to Human Immunodeficiency Virus Particles via Vpr and Vpx

Vpr and Vpx are the auxiliary proteins of human immunodeficiency viruses (HIVs) selectively incorporated into mature viral particles. We showed that the bacterial chloramphenicol acetyltransferase (CAT) fused to the N-terminus of HIV-1 Vpr, HIV-2 Vpr, or HIV-2 Vpx was incorporated into mature virions in a type-selective manner. By using chimeric proteins between HIV-1 Vpr and HIV-2 Vpx, we found that the N-terminal side of these proteins was mainly important for type-selective virion incorporation. The C-terminal arginine-rich region of HIV-1 Vpr was also found to transport CAT fusion proteins into virions but without any type selectivity. Furthermore, the corresponding regions of HIV-2 Vpr and HIV-2 Vpx had no such activity. This region of HIV-1 Vpr may interact nonspecifically with viral genomic RNA. Collectively, Vpr and Vpx may provide a means to introduce foreign proteins and other molecules into HIV virions for therapeutic purposes.