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Biomedical subjects

E Legrand

Publications and source records attributed to E Legrand.

At least 127 records · Page 7Linked to original sources
PubMed1980

[Results of the physiotherapy of arterial disease at the stage of intermittent claudication by programmed efforts training (author's transl)].

The results of treatment of intermittent claudication by a physical training programmed during 30 to 45 days in a rehabilitation center, are assessed on 148 patients of whom 105 have followed a full program at first (32 cases) or after surgery (73 cases). Ankle pressures are not altered. Irrigraphy shows a significant increase of 10 to 14% of the proximal indexes. Walking distance is greatly increased. 13 patients had a walking distance of about 900 m at the beginning and 31 patients at the end of the course ("functional remission"). Out of 105 patients, 98 showed improvement, 4 remained unchanged and 3 slightly worsened. The appreciation of his own progress is a strong psychological stimulation for the patient, this helping him to accent his illness, and to fight the corrigible risk factors of atherosclerosis, all significantly reduced. The interpretation of the results is discussed and shows the importance of non-hemodynamic factors in the achieved progress. The programmed exercise training is one of the best non surgical symptomatic treatments of intermittent claudication.

Adult↗
PubMed1979

Therapeutic efficiency of spleen or bone marrow CFU in X-irradiated 89Sr marrow-ablated mice.

Experiments were carried out to compare the therapeutic efficiency (TE: number of CFU required to reduce the mortality from 100 to 50 per cent) of spleen or marrow (BM) stem cells (CFU) grafted into lethally irradiated mice (807 rad) which had been previously treated with 89Sr or splenectomized. It was found that during the reconstitution of the haemopoietic organs, the spleen does not provide more than 10 per cent of the functional cells necessary for survival. Besides, the BM-derived CFU growing in 89Sr marrow-ablated mice remain twice as efficient as the spleen-derived ones. Similarly, spleen-derived CFU transplanted into splenectomized mice are half as efficient as BM-derived ones. It may therefore be assumed that haemopoietic stem cells grafted into a foreign microenvironment retain their original kinetics of growth and differentiation during 7 to 10 days after their transplantation.

Animals↗
PubMed1978

Defect of erythropoiesis in non-leukaemic AKR mice.

The kinetics of the CFU population and of erythropoiesis were investigated in the AKR strain mouse prior to the onset of thymic leukaemias: haemopoiesis was compared in syngeneic AKR, semi-allogenic C3H and (C3H X AKR) F1 mice injected with AKR stem cells. These experiments demonstrate that the reduction in The number of spleen colonies previously described by Perkins et al. (1971) in syngeneic hosts, as compared to semi-allogenic C3H hosts, is actually related to defective erythropoiesis resulting from a dysfunction of the AKR haemopoietic inductive microenvironment (HIM). Erythropoietin secretion is normal in AKR mice. The early haemopoietic events related to the stem cell: lodgement of the CFU ('f' factor) and doubling time, are not disturbed, but the onset of CFU proliferation is markedly delayed in the AKR strain. The main expression of the AKR HIM dysfunction is a significant reduction in the number of erythroid (E) colonies and an impaired output of red blood cells per E-colony in the syngeneic host as compared to the allogenic one. In addition, data indicate that a weakly histo-incompatible system, such as that in C3H and hybrid hosts, does not interfere with the stages of haemopoiesis except by lengthening the doubling time of the CFU. The results, on the whole, emphasize the prevalent influence of HIM.

Animals↗
PubMed1977

Effect of BNU treatment on leukaemogenesis in lethally irradiated AKR mice restored with bone-marrow and spleen cells.

The leukaemogenic effect of N-butyl-N-nitrosourea (BNU) was studied in normal and thymectomized AKR mice which were lethally irradiated and restored with either bone-marrow (BM) or spleen cells from (AKR X AKR/T1ALD)F1 donors. In some instances T1ALD thymic cells were added to the restorative inoculum. It was possible to determine the origin of the leukemic cells by the metacentric marker chromosomes of T1ALD. The T- or B-cell characteristics were further ascertained by the cytotoxicity test for theta antigen and the EAC rosette test. All leukaemias whether thymic (TLS) or extra-thymic (ETL), developed from donor bone-marrow or spleen cells and never from the injected thymic cells. In non-thymectomized animals BNU increased the percentage of TLS and shortened their latency. Most of TLS which occurred after BNU treatment of BM-restored mice were theta-negative whereas the majority of TLS which occurred in controls and in spleen-restored animals were theta-positive. This suggests that during their maturation process BM-derived T precursors transit through a theta-negative compartment. This compartment does not reach a similar size during the maturation process of the spleen-derived precursors. Adding thymic cells to the restorative inoculum enhanced leukaemogenesis and suppressed theta-negative TLS in BM-restored mice. Thymectomized mice, restored either by BM or spleen, had a low incidence of ETL which was not significantly increased by BNU treatment except in the case of mice restored with spleen cells. The leukaemic cells of one ETL were theta-positive whereas all the other leukaemias had no detectable T or B marker. The percentage of ETL was higher in thymectomized mice treated with BNU alone than in those previously subjected to irradiation and restoration. These results strongly suggest that a theta-negative T precursor could be involved in extra-thymic leukaemogenesis but the possible involvement of a B precursor cannot be rule out unless experiments are carried out with specific markers of T- and B-cell sub-classes.

Animals↗
PubMed1975

Leucémogénése et régénération du systémé lymphoïde chez des hybrides f1 (c3h x akr/t1ald) restaurés par des cellules médullaires et thymiques parentales.

Luekaemogenesis and repopulation of the lymphoid system have been studied in sub-lethally irradiated (c3h x akr/t1ald) f1 hybrids which have been restored with parental Bone Marrow (BM) cells with or without thymic cells. The metacentric marker of the T1ALD sub-strain made it possible to identify the host or donor orgin of leukaemias. Leukaemias occur either in the thymuc (lymphosarcomas) or in the other lymphoid tissues (extra-thymic leukaemias). After irradiation, the precentage of lymphosarcomas increases from 5 to 95%. The rate of leukaemias in hybrids which have been restored only with BM cells is 55, 56 and 100% respectively depending on the origin of BM: syngenic, C3H and AKR. In this last group 75% of the lymphosarcomas originate from donor cells. The inhibitory efficiency of the three kinds of BM on luekaemogenesis seems to be related to their respective abilities to spontaneous malignant transformation. When AKR or C3H thymic cells are injected together with BM cells, leukaemogenesis is altered. The effect is indirect as these cells are not actually concerned by the malignant transformation. The percentage of LS is significantly reduced and the mean survival improved in hybrids restored with C3H thymic, mixed AKR or C3H BM cells. AKR thymic cells are less efficient. In both cases, the percentage of extra thymic leukaemias increases at the expense of lymphosarcomas. Thymic cells do not change the kinetics of repopulation in thymus and lymph-node by the BM cells, except when C3H thymic cells are mixed with T1ALD BM cells; in this case, the lymph-node repopulation is temporarily enhanced. Different hypotheses might explain the effect of thymic cells on leukaemogenesis: enhanced recovery of the postirradiation immunological deficiency, transfer of virus by the AKR thymic cells, and more probably influence of the thymic cells on the maturation or/and differentiation of the lymphoid cells.

Animals↗
PubMed1975

[Influence of allogeneic thymocytes on radioleukemogenesis in AKR-T1ALD mice].

When AKR mice are irradiated with a sub-lethal dose (4 times 175 R), thymic lymphosarcomas (L.S.) occur earlier than in controls. This accelerated leukaemogenesis is not inhibited by syngenic restoration with bone marrow cells (BM). Using the AKR/T1ALD substrain which bears 38 chromosomes with 1 metacentric markers, it has been shown that AKR radio-chimaeras restored by T1ALD BM developed two kinds of L.S. : (i) early (radiation-induced) L.S. originating mainly from host cells surviving irradiation and (ii) late L.S from donor cells. The present experiments were investigate the potential influence of normal allogenic thymic cells, with or without syngeneic B.M., on the incidence, latency and origin of LS appearing in irradiated AKR recipients. Adding C3H allogenic thymic cells to syngenic B.M. increases the percentage of early L.S. whose latencies are unchanged. Besides, when C3H thymic cells are injected to irradiated controls without syngenic B.M. cells, L.S. are seen to occurr significantly earlier than in just the irradiated animals alone. In radio-chimaeras restored by allogenic thymic cells and syngenic B.M., except in one case, all the L.S. were seen to originate from B.M. cells. The interpretation of these results depends on the possible role of allogenic thymic cells on host cells surviving the irradiation, or the exogeneous B.M. In the first case, allogenic thymocytes could induce a graft versus host reaction increasing the post-irradiation depletion of lymphoid system and hastening thymic endoregeneration which is supposed to be the first step towards leukaemogenesis. The second hypothesis, which seems the most likely, would be that C1H thymic cells could selectively act on host cells surviving irradiation and enhance the differentiation of haemopoietic precursors at the expense of the lymphoid cells. Alternatively the thymic cells may co-operate with exogenic B.M., and stimulate their differentiation thus triggering them out of a stage whereby they could become a selective target for the Gross virus.

Age Factors↗