The blood thiamine concentration of 11 subjects was determined
by means of the Friedemann and Kmieciak (1943) method every 5 days
during a 30-day experimental period. Study I was conducted on 5
students in 1947 and Study II was conducted on 6 students in 1948.
The subjects in both studies were on diets in which their intake of
ascorbic acid only was controlled. A record was kept of each subjects
food intake. The daily values for total Calories, non-fat Calories
and thiamine in the diet were obtained from food tables. Non-fat
Calories, the ratio of non-tat Calories to total Calories, thiamine
to 1000 Calories and thiamine to non-fat Calories were calculated.
The blood thiamine values for the subjects in Study I (all girls)
ranged from 4.91 to 10.85 mcg per cent. There was a general decrease
throughout the study in the mean intake of thiamine expressed in terms
of mcg per 1000 Calories and mcg per 1000 non-fat Calories. The greater
the decrease in thiamine intake in terms of mcg per 1000 non-fat Calories
the greater was the loss of blood thiamine. The values for thiamine in
the blood of the boys in Study II ranged from 8.00 to 15.32 mcg per cent
and for the one girl in Study II from 8.35 to 13.93 mcg per cent. The
blood thiamine values for the subjects in Study II did not indicate the
same relationship to thiamine intake as did those in Study I. There was
an increase in the concentration of the thiamine in the blood even though
there was a decrease in the mean thiamine intake from the beginning to the
end of the experiment. It would appear, therefore, that the boys obtained
sufficient thiamine throughout the 30-day period.
No data have been obtained which indicate whether or not there are
variations from day to day in the concentration of thiamine in the blood
when subjects are maintained on a constant intake of thiamine. A
metabolism study using 5 adult women as subjects was planned in order to
determine the daily values for thiamine in the blood when subjects were
maintained on a controlled diet for a period of 52 days. An unpublished
micro-method for the determination of thiamine in the blood developed by
Dr. H. Burch (1948) was to be used.
The experimental diet consisted of a basal diet providing approximately
1000 Calories and 300 mcg of thiamine with additions to the basal
diet planned in units providing approximately 500 Calories and 150 mcg of
thiamine. The values for protein, fat, carbohydrate and total Calories were obtained, from food tables. Non-fat Calories were calculated and
the thiamine content of the food was determined by analysis. All 5
subjects ate the same food each day.
In spite of the fact that considerable preliminary work was performed
before the study started the blood thiamine values obtained in
the nutrition laboratory were always significantly lower than results
obtained by other workers. It was decided to freeze the blood samples
after the protein had been removed and work on certain aspects of the
method before any analyses of the blood thiamine were made.
Further study of the Burch method included variation in the amounts
of potassium acetate used, use of different trichloroacetic acid reagents,
tests for enzyme activity, variations in the incubation procedure,
variations in the procedure for the oxidation to thiochrome and in the
extraction of thiochrome, reading samples sooner after transfer to
optically matched tubes, variations in the irradiation procedure, use of
all new reagents, use of another micro-photofluorometer, development of
standard curves and the determination of the response of two subjects to
an oral test dose of thiamine hydrochloride. None of these variations
resulted in a solution of the problem.
Suggestions for future work with the Burch method are discussed. / Graduation date: 1950
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28287 |
| Date | 12 August 1949 |
| Creators | Cox, Elizabeth Willard |
| Contributors | Storvick, Clara A. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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