Seeding trials

Pharmaceutical companies have, in the past, conducted trials simply to get doctors to prescribe their drug. These seeding trials were often scientifically meaningless and have no clear research question and no controls. They were conducted on a large scale, and investigators (often ordinary doctors, not researchers) were paid to enter patients into the trial. A variant is a switching trial in which a doctor is paid to switch patients from their usual treatment to the new treatment. These sorts of trials will rarely make it into major journals, but many may be published somewhere and then be used to promote the drug. 

Hill, K. P., J. S. Ross, D. S. Egilman, and H. M. Krumholz. 2009. The ADVANTAGE seeding trial A review of internal documents Annals of Internal Medicine 149 251-258. 

Lonally, the templates were chosen by trial and error or exhaustive enumeration. A itafional method named ZEBEDDE (ZEolites By Evolutionary De novo DEsign) en developed to try to introduce some rationale into the selection of templates et al. 1996 Willock et al. 1997]. The templates are grown within the zeolite by an iterative inside-out approach, starting from a seed molecule. At each jn an action is randomly selected from a list that includes the addition of new (from a library of fragments), random translation or rotation, random bond rota-ing formation or energy minimisation of the template. A cost function based on erlap of van der Waals spheres is used to control the growth of the template ale ... 

What Giauque does not tell are the trials encountered in transporting the glycerol seed crystals by dog sled, boat, etc. from Manoose Bay, BC to Berkeley. California, while trying to keep the sample cold so that the seed crystals would not melt. 

Once a suitable strain is available, the prachce is to grow, often ftom a single organism, a sizeable culture which is distributed in small amounts in a large number of ampoules and then stored at 70°C or freeze-dried. This is the seed lot. From this seed lot, one or more ampoules are taken and used as the seed to originate a limited number of batches of vaccine which are first examined exhaustively in the laboratory and then, if found to be satisfactory, tested for safety and efficacy in clinical trials. Satisfactory results in the clinical trials validate the seed lot as the seed from which batches of vaccine for routine use can subsequently be produced. 

A seed dressing method based on electrons was developed and tested by Lindner et al. (1996) and Schauder (2003) as a direct method to improve seed quality and remove/reduce seedborne disease inocula. Electron seed dressing effectively removed common bunt spores (Tilletia caries) and reduced bunt levels compared to untreated seeds in field trials. However, its efficacy against M. nivale has not, as yet, been confirmed. Since this technique has potentially negative effects on germination rates of seed, it is limited to surface treatments (Jahn, 2002 Jahn et al., 2005). 

Protein quality studies evaluating various edible portions of the winged bean plant and the results of recent International Field Trials are reviewed. Research efforts have been focused upon the mature seed (protein content 20.7-45.9% in 240 accessions), which is occasionally eaten in parts of Indonesia and Papua, New Guinea. Autoclaved seed meal and wet heat treated seed meal provided a corrected PER value of 1.76 and 1.72 respectively, in comparison to casein control of 2.50. 

Yield increases in small trials of 25 to 30% have been secured in Louisiana by soil treatment at planting time with a combined insecticide and fungicide. This combined treatment deserves further investigation and it may have promising results. Hot water treatment of seed pieces can eliminate two virus diseases. Germination is stimulated at the same time and the possibility of augmenting this with fungicides has shown promise. Hot insecticides have not been tried. 

During the germination trials 400-400 pieces of tomato seeds were applied. As nutrient liquid raw slurry, purified liquid phase diluted with water in ratio of 1 5 and tap water as control has been used. On the sixth day of treatment 34% of the total seed germinated on the filterpaper moistured with raw slurry, 95% on the filterpaper moistured with purified liquid phase, while in the control sample with tap water 68 per cent. 

An alternative means of conducting trials with a similar outcome to seeding, but without the need to handle crystals, is by dilution. An additional benefit of dilution methods is that they are more amenable to automation compared with seeding techniques (Chayen, 2005). The aim of dilution is to start the trial at nucleation conditions and after a given time... 

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