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Biomedical subjects

A Pompidou

Publications and source records attributed to A Pompidou.

At least 37 records · Page 2Linked to original sources

[Quantification of the diameter of muscular fibres in the course of the development of the quadriceps].

Muscle biopsies were taken from the medium portion of the vastus lateralis of a hundred fetuses (aged between 10 and 40 weeks), children, adolescents and adults without any neuro-muscular disease. Diameters of the muscle fibers were measured with a Leitz ASM 68K on frozen sections which had been stained for myofibrillar ATPase. The results have been expressed as average diameters and histograms. The results demonstrated a gradual increase in diameter of the fibers during fetal development. At the birth, the average diameter of the type I and II fibers is 10-15 microns. Growth continues during postnatal development up until puberty, when the fibers reach their final diameter of 60-65 microns. Analysis of the histograms shows that before 18 weeks of gestation, there is a large dispersion in the diameter of the fibers. The first type I fibers are larger than the others and correspond to Wohlfart type b fibers. This is followed by the appearance of a second population of smaller type I fibers. These fibers gradually increase in diameter and one observes a homogenous population of type I fibers at the birth.

Adolescent↗

[Limb-girdle dystrophy and pregnancy: a case report].

A case of pregnancy with Limb-girdle dystrophy is presented. The course of pregnancy remained uncomplicated, the patient has been delivered at 42 week's gestation by cesarean section, performed for dystocia and fetal distress. Histological and immunohistochemical examinations of the myometrium were unable to show its involvement in the muscular disease. The influence of the muscular disease and the route of delivery for such patients are discussed.

Adult↗

[Rhesus phenotype and lymphocyte subpopulations].

Lymphocyte subpopulations identified by OK3, OK4 and OK8 monoclonal antibodies were studied as a function of certain Rh markers in 2 groups of subjects: 47 children and adolescents with proven reaginic IgE-dependent allergies and 29 healthy adult controls. The Rh antigens C and c were evaluated in their 3 possible configurations: CC, Cc and cc. In both groups studied, the same significant distribution was observed. Allergic cc subjects had the most CD4+ lymphocytes (43.4%) versus CC (34%) and Cc (33.7%), as compared to control cc (42.05%), CC (36.1%). The possible clinical implications of these findings are discussed.

Adolescent↗

The effects of phorbol ester and Ca ionophore on c-fos and c-myc expression and on DNA synthesis in human lymphocytes are not directly related.

Phorbol ester activates human lymphocyte proliferation as measured by [3H]thymidine incorporation and blast transformation. Phorbol ester and calcium ionophore A 23187 induce c-fos and c-myc expression in these cells as shown by the measure of the specific mRNA levels and of the c-fos nuclear protein amount. The combination of these two agents has a synergistic effect on c-fos but not on c-myc expression. Lymphocyte stimulation by phorbol ester for a short time induces c-fos and c-myc expression, but has no effect on [3H]thymidine incorporation. This result indicates that the induction of c-fos and c-myc expression is not sufficient to commit these cells to DNA synthesis.

Adult↗

Immunosuppressive effects of isoprinosine in man: a comparison to chlorambucil effects in multiple sclerosis.

Immunological and clinical functions were studied over a 2 year period in conjunction with a placebo controlled trial of isoprinosine and chlorambucil in 21 patients with exacerbating remitting multiple sclerosis. Laboratory and clinical evaluations were performed at 3 month intervals and during relapses. In placebo-treated patients, the decrease in circulating T8+ cells was maximum during relapses, T lymphocyte function was impaired, and five of the six patients experienced clinical worsening. Chlorambucil treatment was responsible for a decrease in circulating T4+ and T8+ cells; nevertheless, T lymphocyte function was slightly improved during relapses. The alterations of delayed hypersensitivity responses were not accompanied by improvement in relapse rate or in intensity and major side effects: mainly infections with leukopenia and thrombocytopenia. During isoprinosine therapy, a regulation of circulating T lymphocytes and cell proliferation occurred. The higher level of circulating T cells was related to the increase in T4+ and T8+ cells, which did not decrease during relapses. The absence of Leu 7+ cell modifications suggest that NK were numerically unaffected by isoprinosine therapy and that in vivo regulation of circulating T suppressor cells was performed by this treatment. Four out of seven patients did not experience any relapse during the duration of the trial. In relapsing patients, the frequency and duration of the relapses were significantly different from that of other patients. A reduction of the disease progression was observed without any side effects. While no conclusion can be drawn on the long-term effectiveness, the results of this pilot study are consistent indicators of the immunological and clinical beneficial effects of isoprinosine therapy in patients with exacerbating remitting multiple sclerosis.

Adult↗

Immunological effects of isoprinosine as a pulse immunotherapy in melanoma and ARC patients.

Immunomodulatory effect of Isoprinosine are presented in melanoma and HTLV-III/LAV infected patients. Isoprinosine (50 mg/kg) was used as a pulse immunotherapy according to two different schedules: A) 5 days every 15 days and B) 5 days every 15 days for 2 months, then 5 days every 2 months. The patients' immunological profiles were tested before and during the treatment in terms of T-cell subsets, cell number requirement for PHA-induced proliferation, and delayed hypersensitivity reaction to recall antigens. Primary malignant melanoma patients are randomized between surgery alone or associated to isotherapy (schedule A or B). Schedule A, after an initial improvement of surgery-induced immune deficiency, is responsible for an immunodepression, whereas schedule B determines a prolonged restoration in immune responses in melanoma and AIDS related complex or Kaposi sarcoma patients as well. In vitro effects of Isoprinosine on HTLV-III/LAV infection are presented. These data exhibit 1) the need of an immunological follow-up during isotherapy and 2) the immunological benefit of a pulse immunotherapy during acquired immunodeficiencies related to cancer surgery or to HTLV-III/LAV infection in man.

Acquired Immunodeficiency Syndrome↗

The French national program for the prevention and control of AIDS.

The French policy concerning the fight against the acquired immunodeficiency syndrome (AIDS) is a complete and well-balanced one, using information not only for the general awareness of the general population, but also with the help of specific actions aimed at high risk groups. Screening is mandatory for blood, organ and cell donors, but it must absolutely respect individual rights and the rules of ethics. Therefore it must be voluntary and totally respect privacy and professional confidence. France does not undertake screening at the border, but does inform people traveling to and from the country. The monitoring and medical care will be given daily for ambulatory patients, and in specific hospital services according to the symptoms of the others. To save money and to be more efficient, tests will be grouped in specific laboratories. Research is, with prevention, the only hope of stopping the spread of AIDS. More than 50 laboratories are at this moment working, and important funds and materials have been allocated. International cooperation is needed, along with the coordination of the World Health Organization, and the action undertaken by the European Community, to establish the most efficient methods of preventing the spread of this new viral infection that now concerns the whole world.

Acquired Immunodeficiency Syndrome↗

Influence of immunomodulators on T lymphocyte differentiation in ARC patients and resistance to LAV/HTLV III infection.

Isoprinosine and Imuthiol are non mitogenic immunomodulators active on T cell differentiation. In ARC patients, they modulate the circulating T cell receptor complex in terms of OKT4+ phenotype induction. This effect is not responsible for any expansion of the target population but for a partial inhibition of in vitro infection with LAV/HTLV III viral particles. At a clinical level, this means that these drugs may prove helpful in ARC patients when the virus has infected only a few helper cells.

AIDS-Related Complex↗

A selective histochemical method for the quantitative estimation of elastic fibers by computerized morphometric analysis. Effect of colchicin treatment.

A morphometric technique is reported that uses a new selective staining of the elastic system fibers in skin biopsy specimens to facilitate the quantitative evaluation of the volume fraction occupied by these elastic fibers in the tissue. The study of elastic fibers in the dermis of 30 patients, before and after six months of treatment with Colchicin, was carried out with a Quantimet 720 system. Preelastic (oxytalan and elaunin) fibers and mature elastic fibers were quantitated separately. Compared to the average volume fraction (surface occupied by the elastic fibers) before treatment with Colchicin (1.449 +/- 0.64%), the mean values after treatment were significantly increased (2.076 +/- 0.61%). The same results were found for the preelastic fibers: 0.807 +/- 0.51% before treatment and 1.025 +/- 0.54% after treatment. These results demonstrate the advantages of our monochromatic staining method for automatic quantitation of elastic fibers as well as the possibilities of the quantitative study of the elastic fibers in human dermis. This methodology should be applicable to other inherited or acquired diseases affecting skin elastic fibers as well as to other tissues containing elastic fibers.

Colchicine↗

[Stimulation of human lymphocytes by phorbol acetate and a calcium ionophore induces an early transient expression of the c-fos oncogene followed by c-myc].

After stimulation of human lymphocytes by 12-0 tetradecanoyl phorbol acetate (TPA) and by the calcium ionophore A23187 an early transient expression of proto-oncogene fos followed by an expression of c-myc is observed, as has been described in rodent fibroblast stimulated by growth factors. This observation suggests a direct role of protein Kinase C and of calcium flux an the induction of cellular oncogenes fos and myc that may be associated with the early steps of activation and proliferation of lymphocytes.

Calcimycin↗

The generation and regulation of human T lymphocytes by Imuthiol. Evidence from an in vitro differentiation induction system.

In vitro long term induction of human peripheral blood lymphocytes by sodium diethyldithiocarbamate, DTC (Imuthiol) enhanced the expression of OKT and HLA-DR phenotypic determinants. A population of T-B-DR+ cells was recruited from the null cell population. The increase in OKT+ cells, but not the enhanced HLA-DR expression appeared to be macrophage dependent. The surface markers of NK cells, monocytes or the pokeweed mitogen-induced IgM production were not modified. Collectively, the findings indicate that Imuthiol is not a B cell inducer, but is specifically active on the T-cell population in the way it induces the maturation of null cells into OKT+ DR+ lymphocytes.

Antibodies, Monoclonal↗

Isoprinosine and Imuthiol, two potentially active compounds in patients with AIDS-related complex symptoms.

Isoprinosine and Imuthiol are immunomodulators with a unique effect on T-cells. The possibility of using them in treating patients with acquired immunodeficiency syndrome related complex (ARC) was initially examined regarding their in vitro effects on peripheral blood mononuclear cells. In six ARC patients Isoprinosine (100 micrograms/ml) and Imuthiol (10 pg/ml) induced in vitro an early chromatin activation as measured by nuclear refringency test and potentiated phytohemagglutinin (5 micrograms/ml) in the same 20-min assay in the absence of fetal calf serum. In all patients an early phytohemagglutinin induced chromatin dispersion was observed with a dose related response before interleukin 2 production can occur. Isoprinosine and Imuthiol increased significantly both the percentage and the absolute number of T4+ cells when peripheral blood mononuclear cells were incubated for 4 days in RPMI supplemented with 10% fetal calf serum. No changes in T8+ cells were noted. Three homosexual ARC patients were then treated p.o. with Imuthiol (5-10 mg/kg/week) for 4 to 6 months. Without any deleterious effect a clinical improvement (in terms of adenopathy and opportunistic infection regression) and restoration of the response to recall antigens were observed in all three patients. One patient with less than 500 T4+ lymphocytes/mm3 exhibited a complete restoration of OKT profiles. In such patients clinical and immunological effects of Isoprinosine have already been reported by others. Altogether these preliminary results indicate that more data should be obtained on the effects of these two agents in ARC patients.

Acquired Immunodeficiency Syndrome↗

Effect of colchicine on atherosclerosis. III. Study of dermal elastic fibers by quantitative histochemistry, automated image analysis.

Computerized automatic-image analytical procedure was applied on dermal biopsies stained for elastin by a new procedure giving a completely white background and staining only the elastic fiber system. In arteriosclerotic hypertensive patients, a 3-4 months' treatment with 1 mg colchicine per day resulted in a significant (60-80%, p less than 0.01) increase of the dermal elastic fiber density both in the superficial papillary dermis and in the deep dermis. This result shows that the age-dependent increase of elastic fibers can be influenced by pharmacological means. The inhibition by colchicine of the synthesis and secretion of the fibroblast-derived metalloelastase-type protease could be a plausible explanation of this finding.

Adult↗

An in vitro effect of an acute non-specific inflammatory serum on rat lymphocytes proliferative response to PHA.

This study has demonstrated that serum obtained from animals undergoing an acute inflammatory reaction induced by an intrapleural injection of dextran is able to modulate the proliferative response to PHA of lymph node and spleen cells in vitro. This response is dependent on the concentration of the inflammatory serum and on the time of collection of the serum during the acute inflammatory process. At low concentrations of serum (0.5%) stimulatory activity was observed at all time points. At higher concentrations (1%) inhibitory activity was present in 24 and 72 h sera. These results support the previous observation that the acute non-specific inflammatory reaction is able to modify the function of different cell types. It has been suggested that both stimulatory and inhibitory factors are present and the balance between these changes during the course of the inflammatory reaction.

Animals↗

Chromatin structure and nucleic acid synthesis in human lymphocyte activation by phytohemagglutinin.

Alterations in chromatin structure were explored as a function of time following phytohemagglutinin (PHA) activation of human lymphocytes. Nuclear refringency (related to chromatin status), ultrastructural changes, and modifications of nucleic acid synthesis were compared. Chromatin dispersion was observed within 20 min of stimulation, with a concomitant increase in [3H]uridine incorporation; both were inhibited by actinomycin D. Recondensation of chromatin had occurred at 60 min when RNA synthesis was still increasing. The early chromatin dispersion thus was a reversible step and one of the most striking cellular events during the first phase of PHA activation. Late chromatin dispersion of blastic cells during the second phase of PHA response (after 24 h) was related to DNA synthesis in mitotic cells. This step was also inhibited by actinomycin D. These results suggest a relationship between the morphological changes in chromatin structure and the induction of RNA and DNA syntheses. The regulation of transcriptional and replicational states of the nucleus is discussed in terms of modifications of chromatin structure, considering PHA-induced calcium and cyclic nucleotide metabolism and interleukin II receptor expression.

Adult↗

Kinetics of the histological changes in lymphoid organs and of the T-cell inducing capacity of serum in mice treated with Imuthiol (sodium diethyldithiocarbamate).

Sodium diethyldithiocarbamate ( Imuthiol ) triggers in mice an increased production of T-cell recruiting factors and an early and prolonged hyperplasia in the T-cell dependent areas of peripheral lymphoid organs, partially independent from thymus modification. The data confirm previous findings on the role of an extrathymic factor and are consonant with the notion of a feedback regulation to control T-cell differentiation.

Animals↗