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Biomedical subjects

Y Najean

Publications and source records attributed to Y Najean.

At least 181 records · Page 10Linked 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

Maintenance therapy of 32P-induced remission in polycythemia vera. A clinical trial of chlorambucil and hydroxy-urea in 109 cases.

In 109 patients with polycythemia vera, previously treated by 32P without maintenance therapy, a trial was carried out to determine the best way to reduce the number of injections needed. Chlorambucil and hydroxy-urea have been used to lengthnen the remission. Both of them are well tolerated and compatible with follow-up at reasonable time intervals. Chlorambucil maintenance increases the mean duration of remission by 12 months, the best results being observed when the drug was used continuously, instead of an intermittent (3 consecutive days every fortnight) schedule. Hydroxy-urea does not produce statistically demonstrable advantage whatever it is given, continuously or intermittently. Our study shows that, if a long-term cooperative study of the possible advantage of maintenance therapy in P.V. was undertaken in the future, low-dosage maintenance by chlorambucil could be the treatment of choice.

Chlorambucil↗
PubMed1978

[Double medular scintigraphy using 99mTc-colloids and 111In-transferrin in myeloid splenomegaly (author's transl)].

Simultaneously with bone marrow biopsy and 59Fe kinetic study, bone marrow scintigraphy using 99mTc-colloids and 111In-transferrin was performed in 15 patients with a documented diagnosis of agnogenic myeloid metaplasia. This rapid, simple and non-traumatic method permits visualization of changes in the reticular and the erythropoietic marrow which are not always the same. The technique can demonstrate diminution of active marrow in the axial skeleton, peripheral extension of bone marrow and its heterogeneity from site to site. These abnormalities, which vary from case to case, correlated well with the results of 59Fe external countings. The degree of splenic myeloid metaplasia, as judged by 111In uptake, is also well correlated with 59Fe uptake into the spleen. There was poor correlation between scintigraphic and iron kinetic data on the hand, and bone marrow cellularity assessed by marrow biopsy on the other. While scintigraphic studies are chiefly qualitative, they appear to provide useful information for diagnosis, and possibly for prognostic and therapeutic decision.

Aged↗
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

[Aetiological study of aplastic anaemia: analysis of sex, age, profession and habitat in 251 patients (author's transl)].

The sex, age, occupation and residence of 251 patients with aplastic anaemia in adults have been analyzed, and compared to those of the french population. The following observations have been done: excess of males at each age beyond the 20th year; excessive frequency after the 50th year; excessive frequency in the rural population and the inhabitants of villages and little towns; but no excess in the industrial workers. These observations lead to minimize the aetiological responsibility of industrial toxics in aplastic anaemia; at the reverse they invite to look for a possible responsibility of one or several agents used in the rural world.

Adolescent↗
PubMed1978

Erythrokinetic studies in myelofibrosis: their significance for prognosis.

Eighty-three patients with myelofibrosis have been studied by erythrokinetics and have been followed up until death or for at least 12 months. Because of a large plasma volume the venous haematocrit gives only a poor idea of the red blood cell volume. The red cell survival was reduced in the majority of cases but significant haemolysis was rare. The amount of haemolysis of autologous and isologous red cells was similar, suggesting an extra-corpuscular origin for the haemolysis. Plasma iron turnover was always increased, sometimes markedly, but red cell iron incorporation was reduced in 70% of cases, indicating ineffective erythropoiesis. Surface counting showed an absence on diminution of sacral iron fixation and a rapid and marked splenic uptake in more than 90% of the cases; uptake of iron by the liver occurred in half the cases, usually not very high; iron release from the spleen was absent or reduced in 67% of the cases. The degree of ineffective erythropoiesis as measured by radio-iron incorporation and release by the spleen, the amount of haemolysis, and the red cell volume were strongly correlated with prognosis. These factors enabled a more precise prediction to be made of the clinical outcome in the 2 years following the study, than the clinical data alone. A prospective study might show whether erythrokinetic studies are also useful in determining the choice of treatment.

Aged↗
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↗
PubMed1978

[Comparative study of carcino-embryonic antigen and beta2-microglobulin. Methodological study and clinical interpretation (author's transl)].

beta2m was determined by radioimmunoassay in 43 serums from healthy blood donors. Serum concentrations varied from 0.67 to 1.9 mg/l with a mean of 1.29 mg/l. Reproductibility and sensitivity of the method were evaluated. 66 patients with advanced neoplasia were studied. Serum beta2m was greater than 2 mg/l in 70% of the cases and carcinoembryonic antigen (CEA) in 54%. In 26 documented cases with tumor progression and 14 with regression, associated variations of CEA were formed more frequent and of greater magnitude than those of beta2m.

Beta-Globulins↗
PubMed1977

The influence of circadian variations in plasma iron on the measure of plasma iron turnover.

In 92 cases studied in vivo with 59Fe, the variations of plasma iron during the study were measured. Errors in calculation of plasma iron turnover of up to 25% can be made in normosideremic patients if such variations are not taken into account. In hypersideremic patients the variations of plasma iron are low or nil; in hyposideremic patients the slow variations of plasma iron concentration do not alter the rapid slope of radio-iron removal.

Anemia, Hypochromic↗
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

Refractory anaemia with excess of myeloblasts in the bone marrow: a clinical trial of androgens in 90 patients.

In a cooperative trial, 90 patients with refractory anaemia with an excess of blast cells in the marrow were evaluated and treated with androgens. The clinical presentation was very similar to previously published observations: features of medullary insufficiency were less marked than in primary aplastic anaemia; bone marrow blastic infiltration varied from case to case, and remained stable until death or until an acute leukaemic change. All the patients were treated with high doses of androgens as for aplastic anaemia. The efficacy of this therapy was poor. The average life expectancy was 13 months, 64% of deaths being associated with a change to acute myeloid leukaemia. A severe bone marrow deficiency foreshadowed early death, but myeloblastic transformation was observed whatever the initial degree of blastic infiltration of the bone marrow. A comparison with the literature suggests that androgen therapy may accelerate the change to acute leukaemia.

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↗