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Biomedical subjects

O Poirier

Publications and source records attributed to O Poirier.

98 records · Page 6Linked to original sources
PubMed1979

Hydroxyurea suicide study of the kinetic heterogeneity of colony forming cells in human bone marrow.

The kinetics of granulomonocyte colony forming cells have been studied in unfractionated normal human bone marrow by hydroxyurea suicide and in cells separated by velocity sedimentation. Sequential studies revealed two subpopulations of colony forming cells, having different sizes and different multiplication potentialities. There are large cells with a high suicide rate which develop small granulocyte and monocyte colonies during the first week of culture in semi-solid agar. Smaller cells develop larger colonies of granulocytes, monocytes and eosinophils between 2 and 3 weeks of culture. Only granulocyte progenitors have a substantial suicide rate in this small cell population. This population is also less responsive to stimulation than is the large cell class, which is a more highly differentiated progeny. The role of these different kinetics of colony forming cells is discussed in the context of the heterogeneity of the in vitro differentiation of neutrophil, monocyte and eosinophil lines.

Bone Marrow Cells↗
PubMed1978

In vivo platelet kinetics in 31 diabetic patients. Correlation with the degree of vascular impairment.

In vivo platelet survival was estimated, in 31 diabetic patients, using 51Cr-labelled autologous platelets. A mathematical analysis attempted to measure the "potential" life span (senescence process) and the degree of a superimposed aleatory destruction (consumption process). The potential platelet life span in diabetics did not differ from normal values. However, excessive consumption was observed in one third of the studied cases, without correlation with the age of the patients, the clinical duration of diabetes, and the degree of vascular impairment. Thus, platelet kinetic studies did not provide presently useful indications, in a particular patient, regarding the prognosis of the vascular disease, and the justification of anti-aggregant therapy.

Blood Platelets↗
PubMed1978

Prognostic value of in vitro bone marrow culture in refractory anaemia with excess of myeloblasts.

Bone marrow from 17 patients with refractory anaemia with excess of myeloblasts (RAEM) was cultured in methylcellulose semi-solid medium. Compared with normal bone marrow, 3 patterns of growth occurred corresponding with different clinical stages of the condition. Patients whose bone marrow grew normal colonies and those who produced a predominance of microclusters had the longest life expectance, while those who produced a predominance of macroclusters had the shortest life expectancy with a high rate of acute leukaemic transformation. Colony culture appears to be a useful prognostic tool in the condition.

Adult↗
PubMed1977

Cell culture studies in 19 cases of refractory aneamia: comparison of clinical data with in vivo erythrokinetic studies.

A total of 19 cases of chronic refractory anaemia underwent simultaneous in vivo erythrokinetic study and in vitro bone marrow culture. They were followed up clinically for at least 2 years. Good correlation has been found between erythrokinetic data (simultaneous quantitative and qualitative disorders of erythroblastic proliferation in preleukaemic states; pure qualitative disorders in primary sideroblastic anaemia) and the results of culture of granulocyte precursors in the bone marrow (small number of colonies, reduced size of colonies in preleukaemic states; normal number and growth in non malignant refractory anaemia). It would seem thus that both examinations are of practical interest in clinical haematology, making it possible to foresee the malignant evolution of some refractory anaemias.

Adult↗
PubMed1977

Granulopoiesis : studies of bone marrow culture in chronic granulocytopenia and comparison with granulocyte kinetics.

Granulopoiesis was studied in 20 cases of chronic granulocytopenia (adults and children; acquired and congenital). Bone marrow colony growth in methylcellulose culture was compared with the turnover-rate of blood granulocytes labelled with 51Cr and with the bone marrow granulocyte labelling index (L.I.) after "in vitro" flash labelling with 3H-thymidine (3H-TDR). There was a positive correlation between colony forming cells (C.F.C.) content and turnover rate and between C.F.C. content and bone marrow cellularity but there was no statistically valid correlation between C.F.C. content and labelling index. In patients with acquired granulocytopenia the colony counts were increased in cases with autoimmune destruction of neutrophils and in one patient during granulocytic regeneration. The C.F.C. numbers were low in cases with neutropenia associated with granulocyte hypoplasia but the prognosis was better in those cases with the highest colony count. On the other hand, colony counts were variable and had no prognostic value in cases of neutropenia secondary to a bone marrow abnormality in maturation or mutiplication, either acquired or congenital, as revealed by turnover studies and autoradiographic data.

Adolescent↗
PubMed1974

The cellular composition of the granulocyte series in the normal human bone marrow according to the volume of the sample.

The cellular composition of the granulocytic series in normal human bone marrow was studied in aspirates of different volume. An increase in the proportion of polymorphonuclears was observed in samples of more than 1 ml, thus indicating a dilution of bone marrow by peripheral blood. Certain data from the literature, referring to the differential count in the bone marrow granulocytic series, are discussed. The differences between these data can be explained by the dilution of bone marrow cells by mature granulocytes in blood.

Biopsy, Needle↗
PubMedDate not supplied

Changes in the patterns of protein phosphorylation associated with granulocytic and monocytic-induced differentiation of HL-60 cells.

Using two-dimensional gel electrophoresis we have analyzed the pattern of phosphorylated proteins in HL-60 leukemia cells and changes associated with their differentiation into granulocyte and monocyte-like cells. In undifferentiated cells 18 spots with MW ranging from 110 to 17, kDa were individualized with high resolution and reproducibility. Myelocytic differentiation induced by dimethyl sulfoxide (DMSO) and retinoic acid (RA) resulted in a decrease of the overall phosphorylation, the disappearance of two proteins of 42 and 17 kDa, and the appearance of one new acidic protein of 46-48 kDa. These changes seem to be specifically related to this differentiation pathway since they are not found in two HL-60 subclones resistant to DMSO or RA-induced differentiation. Monocytic differentiation induced by 1,25-dihydroxyvitamin D3 [1,25 (OH)2D3] and the combination of RA + 1-B-D-arabinofuranosyl cytosine (Ara-C) was associated with the appearance of 2 proteins of 68 kDa and 2 proteins of 80 kDa located in the acidic region of the gel. The protein of 17 kDa, when disappeared completely in granulocytic-like cells was present in monocytic cells, this suggesting that its phosphorylation state may be involved in the control of the differentiation pathway of HL-60 cells. Data concerning the effect of phorbol myristate acetate (PMA) and histamine on the level of phosphorylation of various proteins in HL-60 cells have also been obtained and discussed. Our results show that the myelocytic and monocytic phenotypes are characterized by a specific pattern of phosphoproteins involving both phosphorylation and dephosphorylation reactions.

Calcitriol↗