Laser-driven proton oncology--a unique new cancer therapy?

In 2000, the University of Strathclyde, collaborating with the Rutherford Appleton Laboratory, organized the first workshop dealing with the potential of high-power laser technology in medicine. Two areas of potential were identified: firstly the production of positron emission tomography (PET) isotopes; and secondly, the potential for laser-accelerated proton and heavy ion beams for therapy. The attendees, mainly clinicians and radiation physicists, emphasised that the laser community should concentrate on developing laser and target technology for therapy rather than isotope production because of the potential advantages over conventional accelerator technology for that purpose. On the 30 March 2007, the universities of Strathclyde and Paisley organized a follow-up meeting to identify the progress made in laser-driven proton and ion beam technology with applications leading to proton and ion beam therapy for deep-seated tumours. The meeting was supported by the Scottish Universities Physics Alliance (SUPA)--an organization set up in Scotland to bring together all of the physics departments collaborating with life scientists to work on ground-breaking new science which no single university could attempt. This is a summary of the meeting.

Mercury in polar bears from Alaska.

Alaskan polar bear (Ursus maritimus) muscle and liver samples collected in 1972 were analyzed for total mercury. Bears north of Alaska had more mercury than bears west of Alaska. The only difference between young and adult animals was in the northern area where adults had more mercury in liver tissue than young animals. Levels were probably not high enough to be a serious threat to bears.

Plasma lipid levels and lipoprotein ratios in ten rodent species.

Cholesterol, triglyceride, and non-esterified fatty acid (NEFA) levels and lipoprotein electrophoretic patterns in blood plasma of ten species of wild rodents are compared with those of the laboratory mouse and man under standard conditions. 1. Average plasma lipid levels for the mouse and man appear in the middle of the wide ranges of 0.6-1.8 g/l. for cholesterol, 0.4 to 2.4 g/l. for triglyceride and 0.32-0.68 m-equiv/l. for NEFA found in these rodents suggesting species may vary in their ability to utilize these lipids. 2. Some universal relationship between levels of cholesterol and triglyceride, but not with NEFA, are suggested by a comparison between average levels in these 12 species. 3. Lack of correlation between the typical four component human lipoprotein electrophoretic pattern with any of the uniquely different patterns of rodents indicate using this method it is not feasible to compare the blood lipid transport system amongst species.

Mercury in Alaskan Eskimo mothers and infants.

The potential danger of natural mercury accumulation in the diet of the Eskimo is evaluated through mercury levels determined in cord blood, placenta, maternal blood, hair, and milk of 38 maternal-infant pairs from Anchorage and the Yukon-Kuskokwim Delta. Although mercury levels are not discernably dangerous, trends to larger accumulations in maternal and fetal RBC and placental tissue with proximity to the sea and consumption of seals during pregnancy provide the basis for considering possible indicators of neonatal involvement. Mercury level in RBC from cord blood appeared as the best potential indicator of this involvement, although relationships with the mother's diet and level of mercury in the placenta also appear useful. In this area, average and maximal mercury levels in cord blood are 39 and 78 ng/ml, respectively, far below the acknowledged toxic level in infants of these mothers who eat seals or fish every day during their pregnancy.

Gluconeogenesis in arctic ground squirrels between periods of hibernation.

The hibernation season in the arctic ground squirrel (Citellus undulatus) is broken into 8- to 18- day cycles by short homeothermal periods during which the carboydrate reserves depleted during hibernation are replenished. This study follows a number of metabolities in tissues and body fluids to assess the sources for reconstitution of the glucose reserves: lactate, urea, ammonia, free fatty acid, glycerol, triglyceride, and glucose in plasma; glycogen in liver and muscle; and urea and ammonia nitrogen in urine. Fat is the major energy source during both homeothermal and heterothermal periods, the contribution from glucose being limited to glycolysis. Reconstitution of glycogen is accomplished prior to reentry through maximal use of substrates from all sources including glycolysis, fat, and protein metabolism. Of the new gluconeogenic substrate, one-fourth is supplied from protein and three-fourths from fat.