Document yZxy7n0n88oYNgD19x9mYMp2

Jun 22,19i|.0 Dr. J. N. M. Chalmers The Royal Infirmary University of Manchester Manchester . Great Britain Dear Doctor Chalmerst Please accept my thanks for the reprints which you sent to me recently. I am happy to comply with your request that I send you some of our reprints. Some additional articles are in press and I will put your name on our list so. that these will he sent to you when they are available. We have not studied the porphyrins in relation to lead absorption and lead excretion. We have done a considerable amount of work in the correlation of stippled cell counts ana urinary lead values. Roughly our results indicate that there is . a considerable variability in the stippled cell counts of normal individuals, that there is also a considerable variability in the same individual at different seasons of the year, and that groups of persons abnormally ex posed to lead compounds show increases in their mean stippling in approxi r?ate accordance with the magnitude of their lead exposure. In our experience there is a considerable variability among individuals in their response to lead exposure. Therefore we have found it impractical to depend upon stippling a 1' an indication of the magnitude of lead exposure of individuals. On the other hand groups of men with rather widely divergent degreesi of lead exposure differentiate themselves obviously from each other on the basis of the mean number of stippled cells per unit volume of blood for the group. , ._ , , -One of tfcP reasonswe have not interested ourselves in the porphyrins up to the present is that we have been concerned chiefly with the earliest evidences of lead intoxication. In as much as HX 002015? 2 hemstopoetic stimulation occurs well in advance of evidences of blood destruction, we have not felt that the study of the porphyrins would be especially useful to us in our line of experimental work. Cordially yours, RAKils Robert A* Kehce, M.D HE 0020158