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Biomedical subjects

Y Najean

Publications and source records attributed to Y Najean.

At least 199 records · Page 11Linked to original sources

[Prognosis of hematopoietic dysplasia (author's transl)].

90 patients with hemopoietic dysplasia (preleukemia) have been studied with iron kinetics for the mechanism of the anaemia, 23 patients had a bone marrow autoradiography and 18 a bone marrow culture in semi-solid medium. The death was caused in half the cases by acute myeloblastic leukaemia transformation (LAM) and in half the cases by complications of pancytopenia (infection, haemorrhage) or hemochromatosis. Three data give prognostic factors at short or long term: the bone marrow hypoplasia, no patient with major bone marrow hypoplasia (ratio of 59Fe fixation in liver and sacrum of more than 2) lived more than 2 years after the examination. The low labeling index of myeloblasts and promyelocytes, the mean LI is 0.20 patients having lived less than one year after the study and 0.35 for those who lived more than two years. The bone marrow culture of the macroclusters type, no patient whose bone marrow grew with macroclusters and no colonies survived more than 8 months after the study. These three data seem to be essential in the regular survey of the patients with hemopoïetic dysplasia.

Autoradiography↗

An analysis of the effect of random and ageing mechanisms on the survival of platelets.

Human platelets survival curves make it possible to estimate two factors which could be held responsible for the disappearance of cells: a) random destruction b) ageing of the platelets. This study was devoted to non-thrombocytopenic patients with chronic vascular disease. In 40% of the cases, the platelet destruction was found to be due to normal ageing of the cells combined with a random destruction process. The estimation of both of these parameters is of interest for the clinical survey of these patients. The statistical analysis of the remaining 60% of the cases presented here has demonstrated a pure linear disappearance of the labelled platelets. This obsveration favours ageing as the cause of the destruction of the platelets.

Aged↗

[Refractory anemias with partial myeloblastosis. Analysis of a protocol comprising 79 cases. 1. Clinical characteristics and evolution under androgen therapy].

Seventy-nine patients with a refractory anemia and partial myeloblastic medullary infiltration have been studied, according to a prospective common protocol. All the patients have been treated with androgens, at high dosage and for at least 10 months if surviving. This study enables to precise the natural history of the disease and to define some criteria valuable for the prognosis. It demonstrates that the classification of this clinical entity as a smoldering or pre-leukemia is justified: 63% of the patients died from acute myeloblastic leukemia. The disease is very severe: the median of survival from the diagnosis is only 13 months. Androgen therapy appears to have little if any effect on the anemia, granulocytopenia and thrombocytopenia; it does not seem to increase the patients' life expectancy.

Aged↗

[Bone marrow insufficiency in the child and androgen therapy. Preliminary results of a prospective schedule of examination and treatment].

The preliminary results of a prospective study of androgen therapy in the treatment of bone marrow insufficiency in children are reported. This study includes 11 children with the Fanconi syndrome, 21 idiopathic and 3 with toxic aplastic anaemia. Nine patients died early in the course of treatment. Impaired liver function was observed in 28% of patients and virilization in 37% of patients.

Adolescent↗

[Comparison of the metabolism of 2 injectable iron preparations (sorbitol iron and polymaltose iron) with the metabolism of transferrin and hemoglobin iron].

Iron distribution in the different organs and chemical compartments of the rat has been studied after intravenous injection of 59Fe-sorbitol (Jectofer-Astra) and 59Fe-polymaltose (Fer Hausmann Lucien) and compared with the metabolism of 59Fe bound to transferrin and to hemoglobin. Both parenteral iron preparations are utilized more slowly than Iron-transferrin. The speed of red cell incorporation of 59Fe from sorbitol is similar to the hemoglobin iron utilization (half incorporation in red cells: 4 to 5 days). Iron polymaltose is much more slowly utilized (half incorporation in the red cells: 13 to 15 days). One third of the 59Fe from sorbitol is eliminated in urine, the remaining iron being taken up to 60% by the liver and to 30% by the bone marrow. It is very quickly catabolized, since as early as the first hour after injection most of the 59Fe is bound to polymaltose till the 14th day. Between the third and fourth week 25% of the 59Fe from polymaltose is found in hemosiderin. These metabolic differences are also found in man: 59Fe from iron sorbitol is found in urine after injection, is mobilized by desferrioxamine after six days, and eliminated through dialysis membranes. On the other hand the 59Fe from polymaltose is slowly but completely utilized and not mobilized by desferrioxamine in the first week after injection. The data give the indications for use and the pharmacokinetics of two forms of parenteral iron and oral preparations in the treatment of iron deficiency.

Animals↗

Prognosis of myeloid metaplasia with myelofibrosis.

The study of the evolution of 168 cases of idiopathic myeloid splenomegaly allowed to point out the prognostic value of the clinical hematologic, isotopic and radiological parameters. The correlation of these data with the histological type of the osteomedullary lesions at the time of the diagnosis, allows to confirm the long survival of the hyperplastic formes (type I) and the more reserved prognosis in advanced myelofibrosis (type II and III together). Indeed, median survival is of 82 months for type I, and 60 months for type II and type III together. It seems advice to gather the two last types and so, to compare two anatomoclinical entities : one is characterized by hyperplastic marrow with reticulinic fibrosis, usually associated with enlarged spleen and sometimes even with increase red blood cells volume but without radiological bone lesions; the other one is characterized by a marrow of middle importance or marked marrow depletion, fibrosis, with or not osteosclerosis, and shows moderate or marked radiological lesions (respectively 16,9% of the cases) and, often, pancytopenia.

Adult↗

A new method for measuring simultaneously the phagocytic and bactericidal capacity of human leukocytes.

A new technique for simultaneously measuring the phagocytic and bactericidal capacity of human leukocytes is proposed. The method uses 14C labelled bacteria and is based on the principle that only viable intra-cellular bacteria incorporate 3H-thymidine. Phagocytosis is measured by the ratio intra-cellular 14C/extra and intra-cellular 14C and the bactericidal capacity of leukocytes by the difference between the 3H-thymidine incorporation of the ingested and non-ingested bacteria. Results in normal subjects and in a case of chronic granulomatous disease show the validity of the method which is easier and quicker than the methods previously used.

Blood Bactericidal Activity↗

[Study of proteins binding radioactive indium in vivo].

After in vivo infusion, radio-active indium is fixed by liver and bone marrow, but more slowly and less completely than iron. It does not incorporate to haem. It is found as labelled ferritin in the liver, after the fifth day. In the bone marrow, indium is almost exclusively found as labelled transferrin; several arguments suggest the intra-cellular site of the labelled protein. Using indium may enable a better knowledge of the intermediary iron pools.

Animals↗

[Practical value of the measurement of red cell volume in anemia].

In most cases of anemia, haematocrit is a good index of the degree of the red blood cell mass decrease; however, in the patients with renal deficiency, hyposideremic anemia, or severe hemolysis, a variable response of the plasma volume to anemia makes any measurement of the hematocrit a poor index of the red cell mass; in patients with splenomegaly, an excess of plasma volume makes any measurement of the treatment. The direct measurement of the red cell mass appears to be useful in clinical practice in many cases with anemia.

Acute Kidney Injury↗

[Practical value of the measurement of red cell volume in polyglobulia].

The practical interest of the direct measurement of the red blood cell volume in clinical haematology remains a matter of discussion. A retrospective study of 385 cases with high haematocrit values shows that the measurement of RBC volume is useful for the diagnosis between true and spurious polycythemia only when the haematocrit value is slightly increased (until 52 p.cent in women and 55 p.cent in men). At the higher values of haematocrit, the direct measurement of the RBC volume does not help for the diagnosis between primitive and secondary polycythemia, but may be useful for the choice of the treatment.

Erythrocytes↗

[Bone marrow scintigraphy in anemia caused by impaired hemopoiesis. Respective values of technetium colloids and indium-transferrin].

Thirty-six patients with different types of bone marrow failure have been studied by double scintigraphy, with 99mTc-colloids and 111In.-transferrin. The observed results are compared to those obtained by bone marrow biopsy and ferro-kinetic studies. Despite our imperfect knowledge of the physiology of indium, and the non-selectivity of this tracer for the erythropoietic line, the good correlation observed in most cases between scintigraphy with 111In. and ferro-kinetics and bone marrow histology is an argument which favours the clinical use of this tracer. A striking difference between the results of scintigraphy with Tc-colloids and scintigraphy with 111In. was noticed in chronic erythroblastopenias, and in most of the aplastic anemias, primitive or due to partial leukemic involvement of the bone marrow. It is suggested that this double study may have an interest for the prognosis in these cases. In patients with lymphoma, treated by radiotherapy and/or chemotherapy, In. and Tc scintigraphies show an extension of active bone marrow to normally inactive zones. It indicates a severe defect of the normally active zones, and appears to be a contra-indication for any supplementary chemotherapy. In myeloid metaplasias, this study may be useful for the choice of treatment, by giving precise indications on the degree of splenic erythropoiesis and of bone marrow cellular depletion.

Anemia, Aplastic↗

[Value of measurement of the red cell volume in polyglobulia and anemia. Expression of the results].

As an introduction to the following paper, devoted to the clinical usefulness of the measurement of the red cell volume in polycythemic and anemic states, the mode of expression of the experimental results of red cell volume is discussed. The comparison between the several equations, which try to give a normal value, by taking into account the height and weight of the subjects shows that the differences are very slight between the several estimations. On the contrary, the expression of the red cell volume as a function of the weight only can be the cause of misinterpretation of the measure of the red cell volume, in fat and thin people.

Anemia↗

[The binding of iron to normal human erythrocyte membranes and its intracellular penetration as a function of different glucides].

In vivo intestinal absorption of iron in rat is greatly enhanced by Lactose and D-Xylose. Both sugars are also able to increase the amount of iron bound to the red cell membrane in the animal. Similar effects have been noted when using human normal red cells. Lactose of D-Xylose are able to convert into an active transport curve the linear diffusion curve which is noted when iron is used without any ligand. It is possible to quantify the effect of both sugars on the flux of iron towards the red cell membrane.

Binding Sites↗

Kinetic studies of 51Cr and DF32P labelled granulocytes.

In vivo kinetic studies of granulocytes labelled in vitro with 51Cr and DF32P were carried out in nine haematologically normal subjects by isolation of the cells in the blood samples by the Ficoll-Isopaque flotation method. 51Cr and 32P specific activity of blood samples made of 93-98% granulocytes was studied. Distribution between marginated and circulating granulocyte pools was identical for both labelled cells and the marginated pool was similar to the circulating pool, except that it was lower in one subject who had a previous splenectomy. The half-disappearance time (T 1/2) was 16.1+/-2.2 h for 51Cr-labelled and 5.4+/-2.1 hr for DF32P-labelled granulocytes. In one case of a normal subject who previously received multiple transfusion homologous 51Cr-labelled granulocytes had a T 1/2 of less than 1 h.

Cell Survival↗

Methods of evaluating the sequestration site of red cells labelled with 51Cr: a review of 96 cases.

Teh technical conditions for surface counting and the methods for splenic and liver sequestration after injection of 51Cr-labelled cells were studied in 96 patients. A comparative study of different sites of positioning of the detection probes leads us to recommend the mid-line at the third intercostal space for the precordial area, the point of maximum count-rate obtained at each measurement for the splenic area, with the patient in right lateral decubitus position and the probe vertical, and a point situated on the midclavicular line 4 cm above the right costal margin for the liver area. A comparative study of different methods of calculation leads us to recommend the method known as 'excess counts', but with a correction of the gross values based on the evolution of circulating radioactivity and not of the count-rate measured over the precordial area. Measurement of urinary excretion of radioactivity showed that only a minor part was due to the loss of the tracer from the sequestration sites, and that the level varied only slightly between subjects. Thus the loss of tracer does not interfere with the interpretation of external counting data. Much of the disagreement regarding interpretation of the results of external counting in clinical practice is due to technical problems. Standardization of techniques of measurement and interpretation of results, selecting those which this study indicates as the most reliable, would permit better exchange of information between laboratories and clearer conclusions as to the practical use of surface counting.

Chromium Radioisotopes↗