Biodistribution of 6-[211At]astato-2-methyl-1,4-naphthoquinol bis(diphosphate salt) and 211At- in mice with a transplanted rectal adenocarcinoma.
6-[211At]astato-MNDP is currently being investigated as a potential high LET endoradiotherapeutic drug. Biodistribution and whole-body radiation retention studies have been carried out with 6-[211At]astato-MNDP and 211At- in a murine rectal tumour model; results indicate that the 211At-C bond in the compound is metabolically stable for at least 6 h. The Mean Biological Concentration of 6-[211At]astato-MNDP in tumour tissue ranged from 170-253% over an initial 12 h period; this was higher than that observed for the [211At]astatide anion. Conversely, the uptake of compound into radiobiologically critical organs was significantly lower.
A cell line from an induced carcinoma of mouse rectum
A tissue culture cell line has been established from one out of seven induced carcinomas of mouse large intestine. The cells have an epithelial morphology and form tumour acini in vitro. Electron microscopy shows that the cells have retained some differentiated characters, including junctional complexes and microvilli with attached glycoprotein strands both in the acini and at the free margins of the cell sheets.
Improving water use in agriculture : experiences in the Middle East and North Africa
Emerging water shortages are of great concern in many countries of the region. As the agricultural sector is generally by far the most important water consumer and higher priority is given to meeting domestic and industrial water demands, it is to be expected that gradually less water will be available for agriculture. An overview is given of present system and on-farm water use efficiencies and the potential for water savings and yield increases through the use of improved distribution networks and more appropriate irrigation technologies for smallholders. The water conservation efforts of Israel, Cyprus and Jordan are examined in detail with respect to institutions, the irrigation infrastructure, water charges and demand management, operation and maintenance, irrigation scheduling and extension, technology development and transfer, the role of the private sector, quality control on irrigation equipment, land tenure and land consolidation, and water users associations. The World Bank's experience with lending for the irrigation sector in the region is also described. The elements that would need to be considered for inclusion in a national program for water conservation in the agricultural sector are identified.