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The effects of hemin on the conversion of pyruvate kinase (PK) isozymes from the M2-type to the L-type in K562 cells were investigated. Immunofluorescence, ion exchange chromatography, and electrophoretic studies showed that the untreated K562 cells contained only the M2-type PK, while eight to 20 days after induction with hemin, concomitant with hemoglobin F synthesis, L-type PK levels increased while M2-type PK levels decreased. Electrophoretic study revealed three hybrid isozymes of the L-type and M2-type PK. We conclude that the conversion of PK isozymes from the M2-type to the L-type in erythroid precursor cells occurs in the early stage of maturation.

The in vitro growth of Plasmodium falciparum malaria parasites was assayed in mutant red cells deficient in either diphosphoglycerate mutase (DPGM) or phosphoglycerate kinase (PGK). In addition, cDNA probes developed for human DNA sequences coding for these enzymes were used to examine the parasite genome by means of restriction endonuclease digestion and Southern blot analysis of parasite DNA. In both types of enzymopathic red cells, parasite growth was normal. In infected DPGM deficient red cells, no DPGM activity could be detected, and in normal red cells, DPGM activity declined slightly in a manner suggestive of parasite catabolism of host protein. However, in infected PGK deficient red cells, there was a 100-fold increase in PGK activity, and in normal red cells, a threefold increase in PGK activity was observed. Parasite PGK could be recovered from isolated parasites, and a marked increase in heat instability of parasite PGK as compared with the host cell enzyme was noted. Neither cDNA probe was found to cross- react with DNA sequences in the parasite genome. It is concluded that the parasite has no requirement for DPGM, and probably has no gene for this enzyme. On the other hand, the parasite does require PGK, (an adenosine triphosphate [ATP] generating enzyme) and synthesizes its own enzyme, which must have been encoded in the parasite genome. The parasite PGK gene most likely lacks sufficient homology to be detected by a human cDNA probe. Enzymopathic red cells are useful tools for elucidating the glycolytic enzymology of parasites and their co- evolution with their human hosts.

In order to compare the polypeptide composition of the CML mature granulocytes with that of the normal whole cell lysates, mature granulocytes from four healthy volunteers and six CML patients were analyzed by two-dimensional gel electrophoresis. In the normal subjects, 60 major spots were commonly and reproducibly identified. In the CML, there were constant alterations in some of these major spots. Four spots were totally absent in all the CML samples, and another four spots were absent in five of the six samples. In addition, one spot was larger in CML than in normal cells, and another spot, which was only faintly visible or not detectable in the normal samples, was massively present in all the CML samples. Our data suggest specific changes in the polypeptide compositions of CML granulocytes. This method could be clinically applied for the analysis of granulocytic disorders.

A case of generalized amyloidosis associated with cyclic neutropenia is presented. A 24-yr-old female with cyclic neutropenia died from intestinal obstruction caused by necrosis and perforation of the small intestine. Post-mortem examination revealed generalized amyloidosis involving almost all organs. Amyloid deposits were prominent, especially in the alimentary tract, kidneys, spleen, and small blood vessels. As has been suggested in gray collie dogs with congenital cyclic neutropenia known to develop secondary amyloidosis in adulthood, an increase of antigenic stimulation during the intermittent bouts of acute infections may be one of the factors responsible for the development of secondary amyloidosis in this case. Although the association of amyloidosis and cyclic neutropenia in man has rarely been described, it is probable that amyloidosis is not a rare complication of human cyclic neutropenia, considering that patients with this hematologic disorder are chronically exposed to excessive antigenic stimulation.