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Biomedical subjects

J Y Follezou

Publications and source records attributed to J Y Follezou.

At least 19 recordsLinked to original sources
PubMed1993

Cerebral arterial disturbances in a transient encephalopathy induced by methotrexate.

The mechanism of the transient encephalopathy induced by high dose systemic administration of methotrexate (HDMTX) is unknown. Metabolic and vascular hypothesis have been formulated but convincing evidence is lacking. We report the first case of vascular disturbances (thinness of cortical arteries on angiography, reversible fall down of cerebral flow and increase of carotid resistance) in a young Algerian patient treated for an osteogenic osteosarcoma. This observation might lead to the exploration by non invasive and easily repeatable techniques of the cerebral vascular dynamic in patients submitted to HDMTX and thus contributed to the elucidation of the mechanism and to the prevention of these neurological side effect.

Adolescent↗
PubMed1993

Class I and II HLA typing after a 10 Gy-4 hour therapeutic total body irradiation.

Class I and II HLA typing was investigated before and at various intervals after a 10 Gy total body irradiation delivered over 4 h, prior to allogeneic bone marrow graft for various hematological malignancies, in 14 patients. A reliable class I HLA typing appeared to be possible in almost all cases 6-8 hours after the start of irradiation but was only possible in 5 patients after 24 h. Preliminary results with class II antigens might suggest a more marked "fragility" of this antigen class after irradiation. These results encourage the drawing of blood samples for HLA grouping as soon as possible after accidental whole-body irradiation.

Accidents↗
PubMed1991

[Immediate hematologic tolerance of extended irradiations after chemotherapy. Apropos of 78 cases of Hodgkin's disease stage III and IV without marrow involvement treated at the Gustave-Roussy Institute].

Early hematotoxicity following 4 to 8 courses of polychemotherapy has been analysed in 78 patients (mean age 32.5 years) treated for advanced stage Hodgkin's disease (53 stages III, 25 stages IV). Toxicity occurred in a third of the patients, and led to interrupt the treatment in one case out of 7, definitively in half of them. The thrombocyte lineage appeared the most sensitive to irradiation. Toxicity was proportional to the target volume (42% of upper and infra-diaphragmatic field versus 11.5% of one sided irradiation, P = 0.01). Toxicity was more frequent after infra-diaphragmatic irradiation (32% of para-aortic field, 43.75% of inversed Y field) than after mantle field (12.3%, P = 0.01). Tolerance to extended field irradiations seemed better in young patients. Sex, stage, type of chemotherapy did not influence toxicity in our series. Abnormalities of the blood count before irradiation was predictive of toxicity. While expecting development of megakaryocytic growth factors of autologous bone marrow transplantation, we suggest: 1) to achieve total lymphoïd irradiation in three periods (mantle field then lombo-aortic field-/+ spleen, then iliac and inguinal fields); 2) to wait, if possible, until normalization of the hemogram before starting the irradiation.

Adolescent↗
PubMed1989

Effect of irradiation on Plasmodium sporozoites depends on the species of hepatocyte infected.

The use of models such as rodents immunized with irradiated rodent malaria sporozoites can be helpful in defining the hepatic antigens which elicit a protective response. After "normal" penetration into the hepatocyte, and "normal" transformation, into trophozoites, irradiated sporozoites are known to begin development, but abort after a period of time that depends on the dose of radiation received. Experiments performed with cultured rat, mouse and Thamnomys gazellae hepatocytes infected with Plasmodium yoelii sporozoites demonstrated that the amount of radiation necessary to totally block the passage from the uninuclear to the multinuclear form differs for each species of hepatocyte. These results underline the problem posed by the models used in malaria research.

Animals↗
PubMed1979

Identification of a pure splenic form of chronic lymphocytic leukaemia.

We have recently proposed a new staging system for chronic lymphocytic leukaemia (CLL) in which patients with isolated splenomegaly are classified into a distinct stage (stage II). Twenty-three such patients (from two institutions) have been studied without recorded death in a follow-up of 18 months to 30 years. This favourable prognosis justifies separation of these 'pure splenic forms' (SCLL) which must be distinguished from what Galton has termed prolymphocytic leukaemia (PL). This distinction can be made on the basis of three criteria: (i) Clinically, SCLL has a slow uneventful course and neither anaemia and/or thrombocytopenia: (ii) cytologically PL can be distinguished from other forms of CLL though atypical forms of CLL may be confused with the former; and (iii) the study of surface membrane immunoglobulins (SmIg) showed that while lymphocytes from most patients with both PL and SCLL bore uniform SmIg, suggesting a monoclonal B-cell proliferation, there was a major quantitative difference in that whereas PL lymphocytes had a number of antigenic sites close to that of normal lymphocytes (mean: 82 000 sites per cell), SCLL lymphocytes had a drastically reduced number of sites. It is our opinion that this is an important criterion for the differential diagnosis between PL and SCLL.

Aged↗
PubMed1978

Visualization of tubulin in lymphocytes. I. Comparison of normal and chronic lymphocytic leukemia (CLL) lymphocytes.

Cell structures containing tubulin were studied in peripheral blood lymphocytes from 8 normal donors and 11 patients with CLL using specific antitubulin antibodies revealed by immunoperoxidase assay. The centriole and microtubules were clearly visible in both groups. A "nucleus-associated tubulin-containing structure" was revealed by antitubulin antibodies and was found in virtually all lymphocytes of normal subjects but in a considerably lower number of CLL lymphocytes. The nature of this structure and its relationship to other cell structures are discussed.

Adult↗
PubMed1978

Ontogeny of B lymphocytes in mice. Quantification of surface membrane immunoglobulins by immunoperoxidase assay.

Surface membrane immunoglobulins (SmIg) of splenic lymphocytes were investigated by immunoperoxidase assay in newborn Swiss mice, their mothers and adult controls. The mean number of SmIg + cells in adult mice was 45-8% and the mean number of antigenic sites per positive cells was 108,500. In newborn mice during the first 7 days of life, values for both parameters were low (24-25--28-5% and 38,000-45,773 respectively) and began to rise after the 10th day to reach adult levels between the ages of 2 and 3 weeks. A peak above adult levels for the mean number of sites per cell was observed on day 21 with a subsequent drop to adult levels on day 28. Post-partum females were found to have consistently fewer sites per positive cell (69,000-86,600) during the 14 days following delivery than their adult control counterparts, though the difference was not statistically significant.

Age Factors↗
PubMed1977

Contribution of quantitative immunocytology to the study of lymphoid hemopathies.

Forty-three patients with a lymphoid hemopathy, three with agammaglobulinemia and six normal controls were investigated with regard to their blood lymphocyte membrane-associated light chains. Detection and quantitation of antigenic determinants were performed by means of peroxidase-labeled antibodies. Compared to normal controls, values found in chronic lymphocytic leukemia (CLL) were very low (tenfold decrease). The number of antigenic determinants on lymphoid cells from patients with blast crises supervening in CLL, prolymphocytic leukemia, Waldenström's macroglobulinemia and Burkitt-cell acute leukemia were significantly higher than those seen in patients with CLL. The data obtained in this investigation through quantitative immunocytology constitutes a new parameter for the classification of lymphoid hemopathies and for an approach to their pathogenesis, in particular if the quantity of membrane immunoglobulin correlates with the stage of cell maturation.

Adult↗