In vitro inhibition of murine hematopoietic progenitors and stromal cells by vinorelbine.

Hematopoietic progenitor colony assays were used to establish the effects of the vinca alkaloid vinorelbine (VRB) on murine bone marrow. The in vitro growth of colony-forming units-granulocyte/macrophage (CFU-GM), burst forming units-erythroid (BFU-E) and colony-forming units-mix (CFU-mix) was dose-dependently inhibited by VRB. The highest dose assayed (0.02 microg/ml) suppressed all of the different progenitor cells by 100%. A comparison of the dose-response curves showed that CFU-GM, BFU-E, and CFU-mix exhibited similar-patterns of sensitivity to the cytotoxic action of VRB. Long-term bone marrow cultures have provided a valuable in vitro model for studying the role of the microenvironment of bone marrow. Cellularity of stromal layers was reduced with increasing doses of VRB. The appearance of these layers was altered minimally with the lowest dose used; a gradual loss of cellularity was seen in cultures exposed to 0.05 and 0.075 microg/ml; and a marked loss at the dose of 0.1 microg/ml. Our results show that VRB has an important effect on hematopoietic progenitors at the highest dose tested, while the stromal cells were not affected at a similar dose (0.025 microg/ml), suggesting that the stroma is more resistant to this drug.

[Myelodysplastic syndrome: experience of the Study and Treatment of Bone Marrow Failure Group]. / Sindromes mielodisplásticos: experiencia del Grupo de Estudio y Tratamiento de las Insuficiencias Medulares (GETIM).

Myelodysplastic syndromes (SMD) were studied in 58 patients (37 men, 21 women; mean age 61 years, range 18-81) who were grouped according to FAB criteria (Table 1). None of them showed a secondary SMD to medullary toxic agents or cytostatic treatments although 5 presented concomitant neoplastic disease. Morphologic alterations in peripheral blood smears and bone marrow were registered by 3 hematologists working independently. The intracellular and extracellular iron deposits were evaluated in every case with Perls; peroxidase activity was determined in 16 patients and intraleucocitary alkaline phosphatase reaction was carried out in 17 patients. Twenty five patients (43%) had refractory anemia (RA); 10 (17%) sideroblastic anemia; 13 (25%) refractory anemia with excess of blasts (AREB); 3 (5%) AREB in transformation (AREB-T) and 7 myelomonocytic leukemia (LMMC). Clinical manifestations at diagnosis are described in Table 2. In the observation period there were cases of anemia requiring transfusion, bacterial infections, muco-cutaneous hemorrhage and hemorrhagic episodes in the central nervous system. In the bone marrow smears the cellularity was normal or increased in 53 cases and diminished in only 3. The degree of dysplastic characteristics (erythroid, granulocytic and megakaryocytic) ranged from low to severe. It was low in most of AR, being the erythroid population the most affected in AS and the granulocytic one in AREB and AREB-T. Patients with LMMC showed similar characteristics to those with myeloproliferative syndromes and the differential diagnosis were sometimes difficult, accounting for their separate inclusion in Table 4. Out of 23 patients, 5 presented clonal pathology detected in cytogenetic studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Sindromes mielodisplásticos: experiencia del Grupo de Estudio y Tratamiento de las Insuficiencias Medulares (GETIM). / [Myelodysplastic syndrome: experience of the Study and Treatment of Bone Marrow Failure Group]

Myelodysplastic syndromes (SMD) were studied in 58 patients (37 men, 21 women; mean age 61 years, range 18-81) who were grouped according to FAB criteria (Table 1). None of them showed a secondary SMD to medullary toxic agents or cytostatic treatments although 5 presented concomitant neoplastic disease. Morphologic alterations in peripheral blood smears and bone marrow were registered by 3 hematologists working independently. The intracellular and extracellular iron deposits were evaluated in every case with Perls; peroxidase activity was determined in 16 patients and intraleucocitary alkaline phosphatase reaction was carried out in 17 patients. Twenty five patients (43

) had refractory anemia (RA); 10 (17

) sideroblastic anemia; 13 (25

) refractory anemia with excess of blasts (AREB); 3 (5

) AREB in transformation (AREB-T) and 7 myelomonocytic leukemia (LMMC). Clinical manifestations at diagnosis are described in Table 2. In the observation period there were cases of anemia requiring transfusion, bacterial infections, muco-cutaneous hemorrhage and hemorrhagic episodes in the central nervous system. In the bone marrow smears the cellularity was normal or increased in 53 cases and diminished in only 3. The degree of dysplastic characteristics (erythroid, granulocytic and megakaryocytic) ranged from low to severe. It was low in most of AR, being the erythroid population the most affected in AS and the granulocytic one in AREB and AREB-T. Patients with LMMC showed similar characteristics to those with myeloproliferative syndromes and the differential diagnosis were sometimes difficult, accounting for their separate inclusion in Table 4. Out of 23 patients, 5 presented clonal pathology detected in cytogenetic studies.(ABSTRACT TRUNCATED AT 250 WORDS)