ALBERT

Description: Intravenous (IV) administration of 5-fluorouracil (5-FU) caused severe hematopoietic injury in mice. Daily administration of purified human recombinant granulocyte colony-stimulating factor (rG-CSF) accelerated recovery from neutropenia in these injured mice. Granulocyte-macrophage progenitors (CFU-GM) in spleen were markedly increased by rG-CSF, while rG-CSF was less effective on the regeneration of CFU-GM in femoral marrow. The accelerated recovery from neutropenia in the mice might be mainly due to the stimulation of granulopoiesis in spleen by rG-CSF.

Description: We examined the in vitro effect of recombinant human granulocyte colony- stimulating factor (rhG-CSF) on neutrophil anomalies in 20 patients with myelodysplastic syndromes (MDS) and eight patients with chronic myelogenous leukemia (CML). Neutrophil alkaline phosphatase (NAP) activity was determined in nine MDS patients and eight CML patients by a scoring method. NAP scores were decreased in six of the nine patients with MDS and in all of the patients with CML. In all patients with these diseases, NAP scores increased by incubating the blood with rhG- CSF. An increase in NAP scores by rhG-CSF was observed even at a concentration of 1 U/mL in patients with MDS but was observed only at higher concentrations (1,000 to 10,000 U/mL) in patients with CML. Significant increases in NAP scores occurred at 12 hours' incubation in patients with MDS, whereas the increase was more gradual in patients with CML. This time course difference was thought to be due mainly to the difference in cell populations of circulating myeloid cells between MDS patients and CML patients. Induction of NAP activity by rhG-CSF in patients with both these diseases was suppressed by the addition of inhibitors of RNA or protein synthesis. Neutrophil superoxide anion (O2- ) production induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was determined in the other 11 patients with MDS. This neutrophil function was decreased in seven of the 11 patients with MDS, normal in two patients, and increased in two patients. Preincubation with rhG-CSF caused a significant increase in fMLP-induced O2- production in nine of the 11 patients with MDS. rhG-CSF enhanced this neutrophil function in a time- and dose-dependent manner, and maximal stimulation was observed at 2,000 to 4,000 U/mL of rhG-CSF and at five to ten minutes' incubation. The present results show that rhG-CSF is able to repair at least in part the neutrophil anomalies in these patients, and our data, especially for patients with MDS, suggest the clinical usefulness of rhG-CSF for this preleukemic disorder.

Description: About 100 derivatives of human recombinant granulocyte colony- stimulating factor (rhG-CSF) were created by various gene-mutagenic techniques, and KW-2228, in which amino acids were replaced at five positions of N-terminal region of intact rhG-CSF, was picked up and evaluated for its biologic and physicochemical properties in comparison with intact rhG-CSF. KW-2228 showed two to four times higher specific activity than that of intact rhG-CSF in mouse and/or human bone marrow progenitor cells by colony-forming unit assay in soft agar, and by cell- proliferation assay in liquid culture. KW-2228 showed a potency to increase peripheral neutrophil counts when it was administered to normal C3H/He mice by single intravenous injection. Increase of total leukocyte count and neutrophils was observed, with peak level at 8 to 12 hours at low doses (0.5 to 1.0 micrograms/mouse), and the highest level was maintained for 24 to 30 hours at high doses (5 to 10 micrograms/mouse). The granulopoietic effect of KW-2228 was examined by several doses of single course (once daily for 10 days) or multiple courses (twice daily injection for 5 days followed by cessation for 9 days on one cycle, 3 cycles in total) of treatment. KW-2228 showed higher activity than that of rhG-CSF, especially at sub-optimal doses of multiple courses of treatment. Furthermore, KW-2228 was found to be more stable physicochemically and biologically than intact rhG-CSF, especially under thermal conditions at 56 degrees C and in the human plasma at 37 degrees C, suggesting a protease resistancy. Pharmacokinetic study showed that plasma concentration of KW-2228 assayed for its bioactivity maintained a higher level than that of intact rhG-CSF for 60 minutes after intravenous injection of this protein to normal mice. Those results suggest that KW-2228 might show a superior in vivo hematopoietic effect to intact rhG-CSF due to its high specific activity to progenitor cells, and also due to its improved physicochemical, biologic, and pharmacokinetic stability in host animals.

Description: We examined the in vitro effect of recombinant human granulocyte colony- stimulating factor (rhG-CSF) on neutrophil anomalies in 20 patients with myelodysplastic syndromes (MDS) and eight patients with chronic myelogenous leukemia (CML). Neutrophil alkaline phosphatase (NAP) activity was determined in nine MDS patients and eight CML patients by a scoring method. NAP scores were decreased in six of the nine patients with MDS and in all of the patients with CML. In all patients with these diseases, NAP scores increased by incubating the blood with rhG- CSF. An increase in NAP scores by rhG-CSF was observed even at a concentration of 1 U/mL in patients with MDS but was observed only at higher concentrations (1,000 to 10,000 U/mL) in patients with CML. Significant increases in NAP scores occurred at 12 hours' incubation in patients with MDS, whereas the increase was more gradual in patients with CML. This time course difference was thought to be due mainly to the difference in cell populations of circulating myeloid cells between MDS patients and CML patients. Induction of NAP activity by rhG-CSF in patients with both these diseases was suppressed by the addition of inhibitors of RNA or protein synthesis. Neutrophil superoxide anion (O2- ) production induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was determined in the other 11 patients with MDS. This neutrophil function was decreased in seven of the 11 patients with MDS, normal in two patients, and increased in two patients. Preincubation with rhG-CSF caused a significant increase in fMLP-induced O2- production in nine of the 11 patients with MDS. rhG-CSF enhanced this neutrophil function in a time- and dose-dependent manner, and maximal stimulation was observed at 2,000 to 4,000 U/mL of rhG-CSF and at five to ten minutes' incubation. The present results show that rhG-CSF is able to repair at least in part the neutrophil anomalies in these patients, and our data, especially for patients with MDS, suggest the clinical usefulness of rhG-CSF for this preleukemic disorder.

Description: Intravenous (IV) administration of 5-fluorouracil (5-FU) caused severe hematopoietic injury in mice. Daily administration of purified human recombinant granulocyte colony-stimulating factor (rG-CSF) accelerated recovery from neutropenia in these injured mice. Granulocyte-macrophage progenitors (CFU-GM) in spleen were markedly increased by rG-CSF, while rG-CSF was less effective on the regeneration of CFU-GM in femoral marrow. The accelerated recovery from neutropenia in the mice might be mainly due to the stimulation of granulopoiesis in spleen by rG-CSF.

Description: About 100 derivatives of human recombinant granulocyte colony- stimulating factor (rhG-CSF) were created by various gene-mutagenic techniques, and KW-2228, in which amino acids were replaced at five positions of N-terminal region of intact rhG-CSF, was picked up and evaluated for its biologic and physicochemical properties in comparison with intact rhG-CSF. KW-2228 showed two to four times higher specific activity than that of intact rhG-CSF in mouse and/or human bone marrow progenitor cells by colony-forming unit assay in soft agar, and by cell- proliferation assay in liquid culture. KW-2228 showed a potency to increase peripheral neutrophil counts when it was administered to normal C3H/He mice by single intravenous injection. Increase of total leukocyte count and neutrophils was observed, with peak level at 8 to 12 hours at low doses (0.5 to 1.0 micrograms/mouse), and the highest level was maintained for 24 to 30 hours at high doses (5 to 10 micrograms/mouse). The granulopoietic effect of KW-2228 was examined by several doses of single course (once daily for 10 days) or multiple courses (twice daily injection for 5 days followed by cessation for 9 days on one cycle, 3 cycles in total) of treatment. KW-2228 showed higher activity than that of rhG-CSF, especially at sub-optimal doses of multiple courses of treatment. Furthermore, KW-2228 was found to be more stable physicochemically and biologically than intact rhG-CSF, especially under thermal conditions at 56 degrees C and in the human plasma at 37 degrees C, suggesting a protease resistancy. Pharmacokinetic study showed that plasma concentration of KW-2228 assayed for its bioactivity maintained a higher level than that of intact rhG-CSF for 60 minutes after intravenous injection of this protein to normal mice. Those results suggest that KW-2228 might show a superior in vivo hematopoietic effect to intact rhG-CSF due to its high specific activity to progenitor cells, and also due to its improved physicochemical, biologic, and pharmacokinetic stability in host animals.