Blood, 1964, Vol. 24, No. 5, pp. 542-552.
© 1964 American Society of Hematology, Inc.
Differences in Proliferative Activity between
Normoblasts and Pernicious Anemia
Megaloblasts
E. G. Rondanelli M.D.1,
P. Gorini M.D.1,
E. Magliulo M.D.2, and
G. P. Fiori M.D.2
1 Postgraduate School of Hematology, Department of Clinical Medicine, University of Pavia, Pavia, Italy
2 Department of Clinical Medicine, University of Pavia, Pavia, Italy
The mitotic behavior of pernicious anemia and normal erythropoietic cells
in vitro was studied by means of phase contrast microphotography and cinema-photograph. Direct measurements showed that the duration of mitosis
is significantly shorter in megaloblasts than in normoblasts at every stage
of maturation. Maturation induces an elongation of mitosis in both the normal
and the pathologic series. The mitotic index being practically the same in
normoblasts and megaloblasts, the weighted average generation time in megaloblasts, calculated according to the formula tG = tM/IM, resulted in a shorter
time than in normoblasts. This indicates that there is a higher than normal
proliferative activity of p.a. cells since the generation time appears inversely
proportional to the frequency by which new mitoses are entered in a cell
population. The role of each single mitotic phase in shortening the total duration of mitoses has been investigated. Possible alterations in the mitotic
mechanisms involved have been discussed.
Submitted on March 6, 1963
Accepted on May 1, 1964
