X-Message-Number: 29811
Date: Sat, 1 Sep 2007 12:51:47 -0700 (PDT)
From: 
Subject: 239'th update on fly longevity experiments

     This is the 239'th update of my fly longevity experiments. Average
 temperature was 23.8 C during this run. Estimated maximal longevity using
 the formula (363 - T*11.2) is 97 days.
     This run was designed to determine whether flies are harmed by
 glycotoxins. To eliminate the possibility of heating destroying enough
 heat labile nutrients to cause malnutrition, only 25% of the fly food
 used in most bottles was heated. Since 75% of the fly food used in the
 experimental bottles was unheated, then nutrient intake would have to be
 at least 75% of that of control bottles, and malnutrition would be
 extremely unlikely. To keep glycotoxin levels as high as in the previous
 experiments the period of heating at 150 C was extended from 30 to 50
 minutes. One bottle used 100% heated fly food to serve as a positive
 control, and thiamin or benfotiamine were added as a test to scavenge
 glycotoxins. Note that neither thiamin nor benfotiamine had any positive
 effect in previous runs (#167 & #171). This means that unheated fly food
 either has no glycotoxins, or that flies are not harmed by them.
     Alas, survival was very poor in all bottles, which I attribute to
 using an older breeding bottle with many diseased flies in it. No
 consistent effect of any intervention was noted, and it appears that
 disease vectors primarily drove the survival results. No definitive
 conclusions regarding glycotoxins can be inferred from the results of
 this run.

 Run #239                 Percent Survival on Day
 supplement            12 20 30 36 43 56 65 72 79 84
 ___________________________________________________
 control one           96 67 44 33 15  7  0  -  -  -
 control two           92 71 38 33  8  4  0  -  -  -
 heated fly food 25%   73 55 27 23 14  9  5  0  -  -
 heated fly food 25%   77 46 27 19 15 12  8  8  0  -
  +benfotiamine 10 mg  70 52 30 11  7  0  -  -  -  -
     "          20 mg  75 66 41 38 13  6  0  -  -  -
     "          40 mg  79 75 43 25 18  0  -  -  -  -
  +thiamine     13 mg  85 70 56 37 15  0  -  -  -  -
     "          25 mg  64 46 18  5  0  -  -  -  -  -
     "          50 mg  74 59 33 15  7  4  4  4  4  0
 heated fly food 100%  74 52 30 15 11  0  -  -  -  -

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=29811