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Biomedical subjects

Y Najean

Publications and source records attributed to Y Najean.

At least 163 records · Page 9Linked to original sources
PubMed1979

[Platelet kinetics during arterial diseases. Macro-angiopathy, cardiac valve prosthesis and prosthesis of the aortic bifurcation: 73 cases (author's transl)].

From 73 platelet kinetic studies in vascular diseases, some conclusions can be drawn: excessive platelet consumption is not as usual as previously published; abnormal platelet recovery is an usual feature in patients with vascular or valvular prosthesis; correlation between platelet kinetic abnormalities and thrombo-embolic complications needs reevaluation; constant abnormal platelet kinetics in the cases of aorto-femoral graft made these cases a valuable model for the clinical and biological evaluation of the drugs committed to a change of the platelet functions.

Adult↗
PubMed1979

[Radio-immunometric determination of the ferritin for evaluation of the iron storage pool (author's transl)].

Seventy-three patients with several haematological diseases have been studied with radio-iron-kinetic, cyto-chemical measurement of iron in the bone marrow, and radio-immunometric determination of the ferritin in the serum. This method gives results which correlate significantly with other methods which evaluate the iron storage pool, in normal or iron-deficient patients. In some cases, an excess of serum ferritin, contrasting with normal serum iron, is confirmed by cytochemical and/or Fe-kinetic studies. In myeloproliferative diseases however, secretion of ferritin by immature cells may induce an excess of serum ferritin. In such cases, the dosage of ferritinaemia cannot be considered as an index of the iron storage pool. Future development of specific dosage of isoferritins could enable to measure the true iron stores, as well as to give an index estimating the evolution of the abnormal cell population.

Bone Marrow↗
PubMed1979

[Gastric emptying of an ordinary meal in man. Study by a radio-isotopic method (author's transl)].

A radio-isotopic method was used to study the gastric emptying of an ordinary meal in 15 control subjects. The technique developed may be used for direct measurement of the early phase of gastric emptying and a simultaneous study of emptying of liquid and solid phases, respectively labelled with Tc99m and Cr51. Emptying of the liquid phase of the meal takes place in accordance with a mono-exponential curve in relation to time, the T 1/2 of which is 54 min +/- 6 (MSD). Emptying of the solid phase is significantly slower than that of the liquid phase. The reproductibility of the method was confirmed and the imprecision of each measurement does not exceed 5%.

Chromium Radioisotopes↗
PubMed1979

[Refractory sideroblastic anaemia of primary and acquired appearance (author's transl)].

This anaemia begun at the age of 40 years. The patient died 17 years later. There was no leukaemic transformation. The authors describe the enzyme abnormalities found in the red cells (increased urosynthetase) and/for of raised serum iron levels in relatives, such that the truly acquired and apparently primary nature of this blood disease must be brought into question.

Adult↗
PubMed1979

[Polycythemias of young subjects (author's transl)].

During the last 12 years, 86 apparently primary polycythemias have been observed in subjects less than 40 years old. In twelve of them a non-suspected cause has been found (seven abnormalities of the hemoglobin function). In 43 cases, all males, the erythrocytosis (red cell volume more than 36 ml/kg) was pure and stable, without any complication; this "benign erythrocytosis" probably depicts extreme values of the normal distribution of the red cell mass. In 31 cases, the disease had criteria similar to those of polycythemia vera observed in older patients; in 12 of these cases, severe thrombo-embolic complications have been observed at the very beginning of the disease; however no further complication has been seen, when the patients were actively treated (phlebotomies or 32P); at the present time, no one of these cases did show transformation into acute leukemia, but the long-term prognosis (beyond 15 years) cannot yet been precisely drawn.

Adolescent↗
PubMed1979

Refractory anemia with excess of blast cells: prognostic factors and effect of treatment with androgens or cytosine arabinoside. Results of a prospective trial in 58 patients. Cooperative Group for the Study of Aplastic and Refractory Anemias.

The results of a prospective study of 58 patients with refractory anemia and partial blastic infiltration of the bone marrow lead to the following conclusions. The median survival (12 months from diagnosis) is shorter and the rate of acute leukemia as cause of death (60%) higher than in other retrospective series. This group of patients, however, appears to be a "continuum" of preleukemic states with more or less rapid evolution, so that the exclusion of the most severe cases appears unjustified. Based on the degree of bone marrow blastosis, and also on the degree of blood cytopenias, the anomalies of 59 Fe incorporation kinetics and the bone marrow stem-cell cultures, it is possible to derive a plausible prognosis for individual patients, which could aid the choice of therapy. Androgen therapy does not accelerate leukemic evolution, but does not improve the bone marrow insufficiency. Cytosine-arabinoside at low dosage exhibited no toxicity, but did not delay the appearance of overt leukemia.

Acute Disease↗
PubMed1979

Prognostic factors in acquired aplastic anemia. A study of 352 cases.

The prognostic factors of short- and long-term survival have been studied in 352 patients with aplastic anemia of all grades of severity. This group was homogeneous with regard to the clinical and laboratory survey, and the treatment used [high-dose androgen therapy]. The "hierarchy" of the individual prognostic parameters has been established: current severe infection, granulocyte count, percentage of the nonmyeloid cells on the bone marrow slides, platelet count, reticulocyte count, 59Fe utilization, and stromal disorganization on the bone marrow biopsy specimen. As these parameters are interrelated, a multiparametric analysis enables us to define groups of patients with different short-term evolution and to derive a prognostic index from these data. The use of such an index, however, allows a correct prediction in only 73 per cent of the cases, better in the milder than in the more severe cases. It is possible that the short-term evolutive tendency (improvement or worsening during the first six weeks of therapy) may contribute supplementary information useful for prognosis and the choice of treatment. After the first three months critical period, the mortality rate no longer depends on the initial severity of the disease but exclusively on the clinical and hematologic improvement. Thus, comparing the hematologic data obtained initially and after three months of androgen therapy allows us to correctly predict the long-term evolution.

Aged↗
PubMed1979

Erythrokinetic studies in hairy-cell leukaemia.

Erythrokinetics were studied in 29 patients with hairy-cell leukaemia. In all cases there was an increase in plasma volume, closely correlated to the size of the spleen, indicating that the true degree of anaemia can only be appreciated by red cell volume measurement. Moderately increased haemolysis was observed in most cases, which did not correlate with the spleen size. Simultaneous study of autologous and isologous red cell life-span suggested an extra-corpuscular mechanism for the haemolysis in most patients. A quantitative erythropoietic defect, either relative or absolute, was found in half the cases, without any qualitative defect. Only one case showed erythroid metaplasia of the spleen. Thus marrow failure appears to be largely responsible for the anaemia and granulocytopenia in hairy-cell leukaemia. A clear correlation was shown between the short-term prognosis after splenectomy and the degree of hypersplenism. However, long-term survival correlated chiefly with the degree of bone marrow failure, whether splenectomy had been carried out or not. The results indicate that isotope studies in hairy-cell leukaemia are useful both in determining the best form of treatment and predicting survival.

Adult↗
PubMed1979

Effect of antilymphocyte globulin on granulocyte precursors in aplastic anaemia.

Granylocyte colony forming units (CFU-C) were studied in 22 patients with severe aplastic anaemia before and after treatment with antilymphocyte globulin (ALG). Nine patients showed a clinical response to ALG characterized by a rise in the granulocyte count to over I X 10(9)/1 within 30 d. These patients were distinguished in vitro from non-responders by an increase in CFU-C numbers after incubation of bone marrow cells with ALG, and by the presence of inhibitors of normal CFU-C in the serum in six out of seven patients tested. In responding patients bone marrow CFU-C rose while most non-responding patients showed no change or a fall in CFU-C after treatment. In addition in three out of four responding patients examined serum inhibitors disappeared after treatment. The horse ALG used in this study also stimulated normal CFU-C in vitro. This evidence is contrary to the hypothesis that ALG stimulates CFU-C in aplasia by inactivating an abnormal suppressor lymphocyte population. The nature of the stimulation by ALG remains unclear. But in practice the effect of ALG on bone marrow cells and study of CFU-C inhibitors in serum could be used to select patients likely to respond to ALG treatment.

Adult↗
PubMed1979

Bone marrow culture in aplastic anemia.

Blood and bone marrow granulocyte colony forming units (CFUc) were assayed in 46 patients with aplastic anemia, and the serum was examined for its inhibitory action on normal CFUc growth. All patients showed a gross reduction in colonies and clusters in incidence and absolute number in the bone marrow and blood. Two proliferative abnormalities of CFUc in aplastic anaemia were identified: a significantly higher than normal cluster to colony ratio (P less than 0.05) and a higher than normal ratio of granulocytes to total aggregates in the bone marrow. Eleven out of 34 patients tested had serum inhibitory to normal CFUc. These patients were indistinguishable from the rest on haematological and CFUc culture characteristics, and no correlation between the results of CFUc assay and haematological severity was found. The results suggest that the CFUc is abnormal in aplastic anaemia, the reduction in pool size being related to a failure of self-renewal, but an immunological role in the pathogenesis of aplastic anaemia remains unproven. The close relationship of CFUc incidence to the percentage of granulocyte precursors in the marrow, together with the failure of the CFUc assay to predict clinical severity, limits the practical use of the assay to the confirmation of diagnosis in aplastic anaemia.

Adult↗
PubMed1979

The use of 75Se-methionine as a tracer of thrombocytopoiesis. I. In vivo incorporation of the tracer into platelet proteins: a biochemical study.

This study was undertaken to define to which platelet components 75Se-methionine is bound after its injection to normal rats, and to study the curves of specific radioactivity of each labelled fraction. It has been shown that, for a part, platelet labelling is due to adsorption of plasma proteins (albumin and fibrinogen) after their synthesis. For another part, methionine is directly incorporated in the bone marrow precursors into platelet actomyosin, a protein constituent of the cells; the variations of the specific radioactivity of this component indicate that 75Se-methionine can be used as a cohort label of platelets.

Actomyosin↗