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Biomedical subjects

A Cruchaud

Publications and source records attributed to A Cruchaud.

At least 37 records · Page 2Linked to original sources
PubMed1982

Opsonic activity of human immune serum on in vitro phagocytosis of Plasmodium falciparum infected red blood cells by monocytes.

In vitro human monocytes from normal blood donors ingest red blood cells infected with Plasmodium falciparum more efficiently than normal red blood cells (NRBC). The phagocytic activity of human monocytes for infected red blood cells (IRBC) is greatly enhanced by the addition of immune sera obtained from individuals living in areas with endemic malaria. In contrast, the addition of sera obtained from individuals recovering from a first infection, or pooled normal sera, does not result in increased phagocytosis of IRBC. The phagocytosis enhancing activity of immune sera is associated with the IgG fraction and IgG depleted sera do not stimulate phagocytosis. Enhanced immune serum mediated phagocytosis occurs as a result of opsonization of IRBC. This was demonstrated by experiments in which monocytes or IRBC were preincubated with immune serum prior to the phagocytic assay. The opsonic activity could be absorbed by IRBC but not by NRBC. The opsonization of IRBC and subsequent phagocytosis were also dependent on the stage of development of the intracellular parasite. IRBC containing schizonts and trophozoites were preferentially phagocytosed as compared with ring forms. The role of malaria induced surface alterations and/or malaria surface antigens in the opsonization of IRBC by immune sera is discussed. These experiments suggest that phagocytosis of P. falciparum IRBC by monocytes may play a role in the immune elimination of malaria infection in humans.

Erythrocytes↗
PubMed1981

[Classification of acute leukemias by surface markers and correlation with the morphological diagnosis. Results of 111 cases].

111 patients with acute leukemia, including 29 children, were classified according to the surface markers and cytochemistry of their blasts. The acute leukemias were separated into two majors groups (lymphoid and non-lymphoid) depending on the presence or absence of specific lymphoid markers. On the basis of these criteria a correlation of 94% with the hematological diagnosis was obtained. Acute lymphoblastic leukemia (ALL) was divisible into three sub-groups: 11 cases expressing T-cell specific markers were classified as T-ALL and 33 cases expressing the common ALL antigen (CALLA) as c-ALL. 18 of the latter expressed an additional marker, DSA (Daudi surface antigen), splitting c-ALL cases in two subgroups. Cytochemistry of the cases lacking specific surface markers (n = 67) served to diagnose 41 acute myeloid leukemia (AML) cases and 8 monoblastic leukemias. The remaining 18 cases could not be classified. The presence of absence of HLD-DR (Ia) antigens served to subdivide AML into two major subgroups. The prognostic significance of these new diagnostic splits is under active study.

Acute Disease↗
PubMed1981

[Evaluation of 2 methods for detecting anti-DNA antibodies in collagen disease].

An immunofluorescent technique using Crithidia luciliae (CL) has been developed to detect antibodies against native DNA, type them and determine their complement-fixing capacity. CL possess a kinetoplast containing double-stranded DNA that is not bound to histones: they are therefore a substrate well suited to the determination of antibodies against native DNA. When compared with a radioimmunoassay the technique displayed the same specificity and sensitivity. However, the correlation between clinical symptoms of SLE and anti-DNA antibody titer was better with the CL method than with radioimmunoassay. Determination of complement-fixing capacity and the type of immunoglobulins did not provide useful information. The CL method proved to be reliable, rapid and cheap.

Adult↗
PubMed1980

Hypergammaglobulinemic purpura and Sjögren's syndrome in a child.

Hypergammaglobulinemic purpura of Waldenström and Sjögren's syndrome are rarely reported in children. This paper reports the case of a 12-year-old girl suffering from both diseases. In the serum of this patient the presence of circulating immune complexs was demonstrated, but there was no clinical sign suggesting an immune complexe disease. After a 28-month follow-up no clinical or biological change was observed.

Antigen-Antibody Complex↗
PubMed1980

Effect of autologous and homologous serum and circulating immune complexes on monocyte functions of patients with solid tumours.

Some functions of monocytes (phagocytosis, bactericidal capacity, handling of endocytosed 51Cr-SRBC and chemotaxis) were studied in fifty patients with solid tumours and in fifty controls. In the presence of autologous serum, the catabolism of endocytosed 51Cr-SRBC and the phagocytic capacity were similar in tumour and control monocytes, while the bactericidal capacity of tumour monocytes was increased. In the presence of pooled AB sera the catabolism and the bactericidal capacity were decreased in tumour monocytes as compared with autologous serum. Tumour sera did not enhance the functions of normal monocytes. Inactivation of pooled tumour or AB sera resulted in decrease of bactericidal capacity in tumour and control monocytes. Using the Clq-binding test, we detected circulating immune complexes in 36% of sera. The presence or absence and the quantity of such complexes did not correlate with the different functions studied in either tumour or normal monocytes. Finally, the chemotactic activity of monocytes was studied using the migration under agarose technique. No difference was found between tumour and control monocytes. On the other hand, the presence of a chemotactic inhibitor was not revealed in tumour sera. These observations suggest that monocytes from tumour patients require factor(s) present in autologous serum as well as autologous cellular component(s) to achieve normal functions.

Aged↗
PubMed1979

The effects of levamisole on some functions of mouse macrophages after in vitro and in vivo administration.

In vitro incubation of peritoneal macrophages from normal, peptone-stimulated mice with levamisole (1-100 microM) for 1 and 22 h had no effect on either phagocytosis of particulate material (sheep erythrocytes, zymosan) or cellular levels and release of lysosomal enzymes (beta-D-glucuronidase, cathepsin D). By contrast, levamisole 1 and 5 mM dramatically increased enzyme release while inhibiting phagocytosis. In some experiments, however, these high concentrations of levamisole caused an elevated cell mortality. When incubation was extended to 72 h, a decrease of both phagocytosis and enzyme release was observed. The catabolism of endocytosed antigens (sheep erythrocytes, human gammaglobulin) was not at all or only slightly modified depending upon the antigen. The cellular level of cyclic AMP remained unchanged in all experiments. In vivo exposure of macrophages to levamisole (2.5 and 10 mg/kg/day i.p. for 3 days) produced a dose-dependent increase in processing of endocytosed antigens as shown by an enhanced transfer of initially endocytosed material to the macrophage plasma membrane. The other parameters were not modified. The immunogenicity of erythrocytes, when endocytosed by levamisole-treated macrophages and transferred into unsensitized recipients, was increased in some in vivo experiments.

Animals↗
PubMed1978

[Cutaneous plasmacytosis and polyclonal cryo-immunoglobulinemia].

A 65-year-old male patient is described who presented with (1) large violet cutaneous plaques on the left side of the body, characterized by dense plasmocyte infiltration of the dermis which appeared benign and largely negative to immunofluorescence, (2) massive polyclonal cryoglobulinemia (type III) without paraproteins, and (3) intermittently marked peripheral monocytosis and thrombopenia without significant medullary changes. Compared with the cases reported in the literature, and after a thorough immunological investigation, this syndrome cannot be entirely assimilated to any entity described up to the present time. Hypothetically, a reactional disorder is the most likely.

Aged↗
PubMed1978

Conditions for maximal synthesis of cyclic AMP by mouse macrophages in response to beta-adrenergic stimulation.

The synthesis of cyclic AMP by mouse peritoneal macrophages in response to stimulation by isoproterenol was studied as a function of drug concentration, incubation time and cell density. Cyclic AMP levels of macrophages increased 3 to 3.5 times over the control level 20 sec after the addition of 10(-3) M isoproterenol. Under these conditions the dose response could be followed down to an isoproterenol concentration of 10(-6) to 10(-7) M. When cell suspensions were inactivated as early as 1 sec after the addition of the drug, the increase in cyclic AMP was much greater (153 vs. 25 pmol/10(7) cells). Macrophage suspensions of high cell density were less responsive than those of low cell density. In the absence of any inhibitor of phosphodiesterase, the stimulatory effect of isoproterenol was always of short duration. The maximum effect of beta-adrenergic stimulation probably occurs in less than 1 sec at a cell density less than 2 x 10(6) cells/ml. The beta-blocking drug Visken abolished the observed effects.

Animals↗
PubMed1977

[Specific and non-specific defense mechanisms against infection].

Defense mechanisms against bacterial, viral or parasitic infections require the cooperation of effector cells (mainly polymorphonuclear and mononuclear phagocytes) and mediators such as antibodies, complement and lymphokines. Antibodies and some complement components promote the endocytosis of microorganisms whereas lymphokines activate phagocytic cells. Once endocytosed, microorganisms are killed either by oxidative reactions consequent to the respiratory burst, or by the particular conditions and factors that they encounter in phagolysosomes. Intact microorganisms or their degradation products handled by mononuclear phagocytes represent immunogenic moieties which can trigger immunocompetent lymphocytes and induce specific immune responses. Phagocytic cells may have characteristic intrinsic deficiencies that are responsible for prolonged or recurrent infections.

Antibodies, Bacterial↗
PubMed1977

[Evaluation of the role of circulating antigen-antibody complexes in the pathogenesis of glomerular nephropathies].

Immunofluorescence studies of the glomeruli in patients suffering from glomerulonephritis (GN) suggest the deposit of immune complexes from the circulating blood. Immune complexes were quantitated using a sensitive radioimmunoassay from sera of 41 patients with GN drawn at the time when renal biopsy was performed. Simultaneously, degradation products of C3 (C3d) were measured. Eleven of 12 patients with GN secondary to a systemic disease (usually LED) presented increased C1q-binding activity of their sera (C1q-BA). C3 was further demonstrated in 9 of these patients, suggesting the presence of circulating immune complexes. By contrast only 2 of 12 patients with idiopathic GN characterized by deposits of complement and IgG in the glomeruli exhibited increased C1q-BA. One of 17 patients with idiopathic GN without deposit of immunoglobulins and C3 in the glomeruli also had increased C1q-BA. The results observed in the group of patients with idiopathic GN with glomerular deposits could be accounted for either by a transitory or minimal presence of immune complexes or by local formation of complexes in the glomerular structures.

Antigen-Antibody Complex↗
PubMed1977

Immunoreactivity to nuclear antigens in systemic lupus erythematosus with or without nephritis, and in other connective tissue diseases, with particular reference to the RNA-protein antigen.

The incidence of autoantibodies to various nuclear antigens was studied in 64 patients with systemic lupus erythematosus (SLE), 137 patients with various connective tissue diseases, 63 other patients and 90 controls. A positive correlation was found between SLE, nephritis and the presence of antibody against native DNA. Antibody to denatured DNA showed no specificity for SLE and was correlated with the absence of nephritis. Antibody to RNA protein occurred mainly in SLE, regardless of the presence or absence of nephritis.

Antibodies, Antinuclear↗
PubMed1977

The functions of human monocytes in normal subjects and in disorders associated with immune deficiency.

Human peripheral blood monocytes were tested for various functions. It was found that 63--70% of monocytes from 12 normal subjects phagocytized either Staphylococcus epidermidis or latex particles; 28% of Staphylococcus organisms exposed to cells were phagocytized in 1 h and 67% were killed within 2 h; 59% of phagocytizing cells reduced NBT; 77% of endocytosed rabbit gammaglobulin was catabolized in 18 h. In Hodgkin's disease, sarcoidosis and severe pulmonary tuberculosis, phagocytic and bactericidal capacity was decreased in one third to two thirds of cases, while catabolism of gammaglobulin was reduced less often and metabolism was practically unmodified. By contrast, phagocytic and bactericidal capacity were practically normal in the common variable form of agammaglobulinemia, while gammaglobulin was catabolized at a low level in all cases. There was no relationship between the functional disorders of monocytes and alterations of lymphocyte stimulation. These results indicate that mononuclear phagocytes may have intrinsic alterations of functions which can result in deficient defense mechanisms and/or immune response.

Adolescent↗
PubMed1977

Glomerulonephritis associated with hepatitis B. report of a case and review of the literature.

A 45-year old developed membranoproliferative GN seven years after acute hepatitis. He was found to be a chronic carrier of HBsAg, and glomeruli contained granular deposits of immunoglobulins (Ig), complement (C) and HBsAg. Six months later, HN persisted, but HBsAg has disappeared from glomeruli; Ig and C were still present. It was concluded that GN was probably due to a hepatitis B associated antigen, but not necessarily to HBsAg.

Acute Disease↗
PubMed1976

[The immunologic status during pulmonry tubercuolsis].

The cellular and humoral immunity of patients with pulmonary tuberculosis has been evaluated prospectively in 22 PPD-positive and 10 PPD-negative patients by intradermoreaction (IDR), blast transformation (SL) and MIF production in response to PPD, Candida and varidase, peripheral lymphocyte count, and quantitative evaluation of immunoglobulins. There is a very good correlation between the different tests, and anergy is frequently found in elderly patients. Negative results (IDR, SL, MIF) are significantly observed in the presence of a negative PPD-IDR, lymphopenia (less than 1,000/mm3), impaired blast transformation in response to PHA (less than 21,000 cpm), and a cavitary form of tuberculosis. These findings suggest a defect of cellular immunity in these patients.

Aging↗
PubMed1976

[Granulocyte transfusions. Technical data, granulocyte function and results].

A new method called "repetitive filtration leukopheresis" is described for granulocyte transfusion therapy. 23 patients received a total of 91 transfusions. All patients presented neutropenia of less than 300/mm3 and various kinds of infection resistant to antibiotic therapy. A favorable result was observed in 18 cases following these transfusions, which did not produce the secondary effects noted by others (chills, rash, fever, dyspnea). It was felt that this remarkable tolerance was a result of the collection procedure (elution at pH 7.4 ommission of centrifugation, thus securing the functional integrity of the cells). This impression was confirmed by the results of a battery of tests performed on the collected granulocytes, which included evaluation of their phagocytic and bacteriolytic functions and of their ability to break down a phagocytized antigen, together with measurements of lysosomial enzymes released in the supernatant.

Bacteriolysis↗
PubMed1976

[Human monocyte function in normal subjects and in certain states of immunologic deficiency].

The functions of peripheral blood monocytes (phagocytosis, bacteriolysis, the metabolism, and catabolism of a protein antigen) have been studied in 12 normal subjects and in 23 patients suffering from either primary or secondary immune deficiency. Phagocytosis and bacteriolysis were altered in 1/3-2/3 of patients with either Hodgkin's disease, sarcoidosis or pulmonary tuberculosis, whereas catabolism of the protein antigen were found to be abnormal in practically all cases of agammaglobulinemia. These results show that monocytes may have intrinsic functional abnormalities in some conditions.

Agammaglobulinemia↗