Biomedical subjects

C Revol

Publications and source records attributed to C Revol.

6 recordsLinked to original sources

PubMed1998

[Determination of alpha 1 antitrypsin phenotypes in plasma using isoelectric focusing on this agarose gel].

Plasma alpha 1 antitrypsin (alpha 1 AT) is the major serine protease inhibitor (Pi) in plasma. It is a glycoprotein, which presents many molecular variants. Allelic phenotypes are classified alphabetically according to their electrophoretic mobility in the Pi (Proteases inhibitor) system. More than 75 distinct protease inhibitor subtypes have been identified using isoelectric focusing (IEF). The major interest for detecting its microheterogeneity is the rare possibility of deficient alleles, which are responsible of low amounts in the alpha IAT production. The clinical use of the alpha 1AT phenotyping is the diagnosis of hereditary alpha 1AT deficiencies. The most common normal phenotype is MM; the major deficient phenotypes are MS, MZ, SS, SZ and ZZ. Hereditary deficiencies of the Pi, the most common inborn error in European people, lead to pulmonary emphysema in young adults or liver cirrhosis in children. IEF on polyacrylamide gels is the reference method for alpha 1AT phenotyping, but is very difficult to standardize. In the present study, we have developed IEF on agarose gels for Pi subtyping within a number of technical improvements. A 0.5 mm thin agarose gel (1.6%) is cast on polyester film; focusing is performed using carrier ampholines (pH = 4.2-4.9), using a very high voltage. Staining is done with a simplified silver nitrate method. The patterns of the different Pi phenotypes obtained with our technique are very attractive. The common subtypes corresponding to the alleles M1, M2, M3, S, Z are univocally demonstrated. Agarose gel allows the advantage of using a non toxic substance. Further the gels are easy to produce and the method is accessible to all clinical laboratories.

Alleles↗

PubMed1996

[Agarose gel isoelectric focusing: application to the study of abnormalities of immunoglobulin clonality in CSF and serum].

Since it is quite difficult to commonly use isoelectric focusing (IEF) of proteins in polyacrylamide gel for biological diagnosis, we have developed a method based on IEF in agarose gel, to split proteins from sera and cerebrospinal fluid (CSF). A prefocalisation at low voltage (250 V) is made on a custom thin gel of agarose (0.5 mm) containing some carrier ampholytes (pH 5-9). After deposition of biological samples, the gel is run at 500 V, thereafter at 1200 V. After focusing, the gel is fixed before being coloured by a simplified silver staining technique. In order to demonstrate the good resolution of the immunoglobulines (Ig) in the pH gradient, a transfer on a nitrocellulose membrane followed by an immunofixation was carried out from unstained gels after IEF. This separation on agarose gel shows several advantages, ie its speed (3H total), its lack of toxicity, its sensibility and its reproductibility. It is specially well suited for the diagnosis of diseases characterised by oligoclonal or monoclonal Ig, particularly those found in the CSF during neurologic diseases like multiple sclerosis. Several examples of focused sera and CSF are reviewed in the paper.

Cloning, Molecular↗

PubMed1994

Post-therapeutic evolution of serum chlamydial antibody titers in women with acute salpingitis and tubal infertility.

OBJECTIVE: To determine if serologic data and, more particularly, antichlamydial immunoglobulin (Ig) M can be used for diagnosis of current chlamydial intrapelvic gynecologic infection. DESIGN: Forty-two women with acute salpingitis (group A), 131 women with tubal factor infertility (group B), and 98 pregnant women (control group C) were studied. SETTING: Hôpital Jean Rostand, Sèvres (patients), Laboratories Magenta and Eylau, Paris (serology), Institut Pasteur, Paris (cultures). INTERVENTIONS: Study groups: endocervical/urethral swabs, pelvic samples; serologic study before and after treatment. CONTROL GROUP: Serologic study. MAIN OUTCOME MEASURES: Serum samples were collected from each patient initially and 6 to 9 weeks later; additionally, two to five sequential sera were obtained from 22 (group A) and 25 (group B) patients with positive cultures, evolutive serology, or positive antichlamydial IgM. Sera were tested for antichlamydial IgG by a microimmunofluorescence assay using Chlamydia trachomatis elementary bodies and for IgA and IgM by whole inclusion-fluorescent assay. RESULTS: Before treatment, there was a correlation between the presence of antichlamydial IgM and positive cervical and/or intrapelvic chlamydia cultures. After treatment, antichlamydial IgM, when initially positive, rapidly disappeared in most subjects; its persistence after 4 months was significantly associated with tubal sequelae in group A patients and persistence of positive intrapelvic chlamydial cultures in group B women. CONCLUSION: Serologic analysis of women with acute salpingitis or tubal infertility, including antichlamydial IgM, may aid both in the before treatment diagnosis of chlamydial infection and in the follow-up evaluation.

Acute Disease↗

PubMed1993

Absence of both subunits of cytochrome b558 in the UM384 cell line relative to the inability to generate superoxide anions.

Phagocytic cells are characterized by their ability to generate superoxide anions upon activation by appropriate stimuli. UM384, a myelomonocytic cell line, was shown to be defective in this oxidase activity as measured by nitroblue tetrazolium or cytochrome c reduction. Cytochrome b558, a unique pigment present in phagocytes and implicated in electron transfer from NADPH to O2, was absent in the differentiated UM384 cells. Both subunits of the cytochrome b558 appeared to be absent or present in strongly reduced amounts compared to the mother cell line U937, as indicated by immunocytochemistry or Western blot analysis using monoclonal antibodies (MABs). On the other hand, cytosolic factors also involved in NADPH oxidase activity were shown to be present, either immunologically or by using the capacity of the cytosol to activate the oxidase in a membrane fraction from bovine neutrophils. At the molecular level, the mRNA that encodes the gp91-phox was shown to be absent in the differentiated UM384 cells, whereas the mRNA that encodes the p22-phox was normally expressed. These results suggest that the defect in superoxide production by the UM384 cells is related to the absence of cytochrome b558, a situation mimicking that observed in phagocytes from patients with X-linked chronic granulomatous disease (X-CGD).

Antibodies, Monoclonal↗

PubMed1992

Modulation of human neutrophil function by fibronectin degradation products isolated from cryoglobulins.

The proteolytic fragments of native fibronectin (cryopeptides) complexed to pathological immunoglobulins in cryoglobulins were isolated from the serum of six different patients. Two peptides of 117,000 daltons and 70,000 daltons were purified and characterized by N-terminal amino acid sequencing. The priming effect of the mixture of these two peptides, referred to as cryopeptides, on neutrophil functions, namely the respiratory burst, exocytosis, and Ca2+ release, was investigated. Cryopeptides and cryoglobulins assayed separately did not increase neutrophil respiration or cytosol free calcium concentration; however, both of them induced granule enzyme secretion. Sequential exposure of neutrophils to either cryopeptides or the respective cryoglobulins, and then to N-formyl-methionyl-leucyl-phenylalanine or serum opsonized zymosan, resulted in a synergistic stimulation of O2 uptake compared to the effect of N-formyl-peptides or opsonized zymosan tested separately; Ca2+ release was significantly enhanced by the pretreatment of neutrophils with cryopeptides. These data suggest that cryopeptides and cryoglobulins may play a role in host defense against bacterial infections through neutrophil activation.

Amino Acid Sequence↗

PubMed1989

[Post-puberty anorexia nervosa].

Post-puberty anorexia nervosa requires a thorough clinical study to facilitate its diagnosis and its early treatment. Longitudinal studies have demonstrated that good results usually depend on the speed of medical intervention (preferably with admission to hospital) and to the duration of treatment. The fact that certain cases result in death is too often due to excessive intensive care. Infusions must be avoided at all costs and should be replaced by forcible feeding if absolutely necessary. Finally, a better approach to, and a better understanding of adolescents should contribute to the prevention of anorexia nervosa.

Adolescent↗