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M Aymard

Publications and source records attributed to M Aymard.

At least 127 records · Page 7Linked to original sources
PubMed1986

[Sterility and Chlamydia infection. Risk factors].

The authors distributed a questionnaire to 89 patients who consulted them for sterility for reply by themselves. The blame for chlamydia trachomatis infection as a cause of sterility was worked out as a level of IgG above 1/8. The risk factors for being infected with chlamydia trachomatis is above all the number of sexual partners; the odds ratio of 2,68 being significant for those who had more than one partner. The age of marriage and the age at first intercourse do not count. The prevention of the consequences of infection depends on education about the risks and screening for infection when the partner is changed.

Age Factors↗
PubMed1985

[The persistence of activity of H1N1 (swine) influenza virus in pig breeding units during non-epidemic phases].

A study is carried on in a group of 16 commercial breeding-finishing units in Brittany (France). The aim of this study is to try to reveal the persistence of activity of the Influenza Virus within these intensive units after an acute epizootic. In each farm two batches of pigs are selected, individually identified and followed from suckling period to slaughter. Serological controls are conducted every month on the same pigs. Both Influenza and Aujeszky's disease antibodies are apprehended. Furthermore nasal swabs and lungs are submitted to analysis for virus isolation purposes and data are collected from each herd for epidemiological studies. Influenza passive H.I. Antibodies rapidly decrease in the piglets. Later a seroconversion is observed in 10% of the investigated piglets. These pigs belong to 4 herds. The conversion happens usually after 3 months of age. All attempts to isolate the virus failed. Special herd conditions may be associated with a persistence of the viral activity inside the units between epizootics: bad demography (unbalance in the breeding stock), inadequate hygiene policy in the fattening house (with permanent arrivals of pigs coming from subsequent batches of sows), a high prevalence of respiratory and specially pulmonary enzootic diseases. A seroconversion against Aujeszky's disease is pointed out in 3 out of the 4 herds concerned with Influenza virus activity suggesting that closely the same conditions may be related both to influenza and Aujeszky's disease virus activity.

Animals↗
PubMed1985

Rapid diagnosis of echovirus type 33 meningitis by specific IgM detection using an enzyme linked immunosorbent assay (ELISA).

During an outbreak of meningitis in France (in the Lyon area), from June to October 1982, serum and stool samples were collected from 227 patients. An enzyme-linked immunosorbent assay (ELISA) for titrating IgG and IgM antibodies anti-echovirus type 33 was developed and compared with the virus isolation technique, and with the titration of neutralizing antibodies. In 39 patients excreting echovirus 33 in faeces, the ELISA test allowed a positive serodiagnosis in 85% of the cases by detection of specific IgM (64% of the cases) and by seroconversion (21%). Compared with the neutralization (Nt) test, ELISA was found to be more sensitive. The antibody titres in ELISA were over 50 times higher and detected earlier than the neutralizing antibodies. This early immune response allowed a rapid diagnosis by specific IgM detection in the acute sera collected within 8 days after the appearance of the clinical symptoms in more than 50% of the 97 patients examined, whereas the Nt test allowed a positive serodiagnosis in only 32% of the patients. The use of a caesium chloride purified antigen insured the specificity of the reactions.

Adolescent↗
PubMed1985

[Immunologic markers of the risk of cytomegalovirus infection among immunosuppressed patients].

ELISA and complement fixation test (CF) were compared for the determination of the Cytomegalovirus (CMV) humoral immune status of donors and recipients before and after graft. ELISA-IgG was more sensitive than the CF test and permitted a better identification of the high risk donors and recipients. The presence of IgM antibodies in the recipient at the day of transplantation is an index of greater susceptibility to chronic or recurrent infection at a later date. In primary renal allograft recipient the detection of specific IgM antibodies by ELISA provides more rapid diagnosis than that by CF. In bone marrow transplants, ELISA-IgM showed a better correlation with the virus isolation than the CF test. In the reinfected renal allograft patients the presence of IgM was related to clinical manifestations. Using ELISA, specific decreases of CMV antibody titers were detected before virus isolation.

Adult↗
PubMed1985

Recovery of reoviruses from tap water.

Samples of piped water were taken from the source of the springs in ten villages in Lorraine. Usually this water has not been subjected to disinfection. The water was tested for fecal indicator bacteria, phages and animal viruses. Of the ten samples examined, seven contained no fecal indicator bacteria, phages or animal viruses, in three samples, however, Reovirus type 2 was found. Among the three positive samples only one contained fecal bacteria and phages. Consequently, the two other samples could be regarded as drinking water, despite the presence of viruses. Such an approach poses the problem of testing drinking water for viruses and suggests that viral tests should be undertaken as part of the water quality control.

Animals↗
PubMed1985

Antigenic characterization of influenza A (H1N1) viruses recently isolated from pigs and turkeys in France.

The spread of influenza A viruses from one animal reservoir to another forms an important part of the epidemiological study of influenza. The precise characterization of viral antigens by monoclonal antibodies makes possible an interesting immunological approach to the transfer of strains from one reservoir to another.This work has shown that the recent porcine strains in France, Belgium, and Spain are closely related antigenically, and distinct from the A/sw/NJ/8/76 strain. Their prototype is strain A/sw/Fin/2899/82.An avian strain, A/ty/Brit/46/83, which has caused limited epidemics of reduced egg-laying among turkeys, has a haemagglutinin identical with that of strain A/sw/2899/82.This immunological finding, combined with epidemiological information (geographical location and absence of any influenza antibody in turkey farms in previous years), suggests that the transfer of influenza viruses has taken place in the direction from pig to turkey.

Animals↗
PubMed1985

[Immunovirologic markers of the risk of influenza A H3N2 among swine].

A seroepidemiological survey using the radial haemolysis test has been performed on a representative sampling of the pig herds in Brittany. Since 1978, Influenza A H3N2 strains spread in that reservoir giving subclinical infections. We detected antibodies directed against the Influenza prototypes isolated during the human outbreaks from 1973 to 1977. Only one H3N2 virus was isolated in 1980: its antigenic structure was in agreement with the previous serological data. In 1984 outbreaks of swine Influenza A H3N2 occurred. The isolated viruses carried an hemagglutinin antigenically identical to the one of the 1980's strain but the neuraminidase looked clearly different. When studying the specific immune response of the young animals to the influenza infection, it appeared that the hemagglutinin of the 1984's viruses antigenically varied from the 1980's ones in about 2/3 of all the animals. With monoclonal antibodies anti N3 and N2 of the human prototypes we confirmed the data obtained in using the post infection ferret antisera. Monoclonal antibodies directed against the swine H3N2 1984 viruses are in preparation. We have no precise information so far on the mechanism of the antigenic variations.

Animals↗
PubMed1984

[Immunological diagnosis of cytomegalovirus infections. Application to blood transfusion centers].

The Blood Transfusion Centers (B.T.C.) are mainly concerned with the selection of CMV infection free blood donors, the screening of the anti CMV antibody high titre plasma donors and the evaluation of specific anti CMV Immunoglobulin preparations. Various serological methods could be used but they are of different value depending the purposes of the B.T.C. The neutralization test (Nt), with the addition of complement is specific and detects the protecting AB against the glycoproteins of the viral envelope. The complement fixation test (CF) using extracts of CMV infected cells as antigen largely varies in its sensitivity according to the quality of the antigen. In any case, the CF test is not sensitive enough to detect a latent CMV infection in a certain percentage of the non immunosuppressed adults, but could be used for the selection of anti CMV antibody high titres carriers. Three sensitive methods: passive haemagglutination, indirect immunofluorescence and indirect ELISA tests, might be used for the detection of latent CMV infections. They detect various AB against various internal and external components of the CMV. They are submitted to various sources of errors. The sensitivity of the indirect IF test is mainly restricted by the quality of the antigen preparation, its specificity by the presence of anti cells antibodies in the sera, the Fc receptors in the antigens and the specificity of the conjugates. The indirect ELISA which is submitted to the same causes of errors is a highly sensitive test, easy to perform, reagents are available, and automatic processors have been developed. When compared with the previous techniques, the ELISA test is suitable for the screening of CMV free donors, when it is performed with an highly sensitive antigen. It could be also used for the screening of high antibody titre carriers: its correlation with the CF test is quite good (r = 0,82). When comparatively applied to the titration of Immunoglobulins preparations, made from plasmas or placentas, for either IM or IV administration, the Elisa test gives AB titres different from those obtained with Nt and indirect IF. The calibration of a standard Immunoglobulin reagent is urgently needed and double blind clinical assays of the protective effect of various preparations of specific anti CMV Immunoglobulins have to be promptly designed.

Antibodies, Viral↗
PubMed1984

[Clinical use of immunoglobulin titers of anti-cytomegalovirus antibodies].

The frequency and severity of CMV infections in kidney, bone marrow, heart transplant recipients, in polytransfused patients, in immunodeficiencies and in newborns with congenital or peri-natal infection prompted clinical trials of immunoglobulins (Ig) with anti-CMV activity. Among the various methods for titrating Ig of plasmatic or placental origin, polyvalent or hyperimmune, ELISA would be the most sensitive assay and the neutralizing reaction might be the better reflection of a protective effect. In kidney transplantation, two non-randomized clinical trials have suggested a curative effect in association to other treatments, especially when given early. In bone marrow transplantation, three randomized studies have shown a prophylactic effect on incidence of symptomatic infections, interstitial pneumonias due to CMV, but only in seronegative patients not treated with leucocyte transfusions. No effect was observed on the time of infection, the survival of patients, the incidence of surinfections or graft versus host disease. The prophylactic effect of anti-CMV Ig in kidney and heart transplantation as well as in newborns has still to be documented in randomized trials. The possible clinical benefit for the patients and the mode of preparation of effective anti-CMV antibodies need further investigations.

Antibodies, Viral↗
PubMed1984

Contribution of monoclonal antibodies to the study of parainfluenza virus antigens.

Splenic lymphocytes from BALB/c mice immunized with Parainfluenza 1 virus (PIV-1), HA2 strain, were fused to the non secreting 653 and secreting P3 X 63Ag8 myeloma cell lines. Fusion products were screened for antibody synthesis using an enzyme-linked immunosorbent assay (ELISA) with purified PIV-1. Antibodies were characterized by their biologic specificity and immune fluorescence staining--6 monoclones (2HI and 4 non HI) were used to further analysis by cross reactivity panels using different PIV strains. None of the anti PIV1 monoclones showed any cross reactivity with PIV2 and PIV3 whereas with HI and non HI monoclones antigenic relationships were observed between viruses belonging to serotype 1. Monoclonal antibodies were also applied to the study of host cell related changes in PIV1 proteins.

Animals↗
PubMed1984

Antigenic comparisons of swine-influenza-like H1N1 isolates from pigs, birds and humans: an international collaborative study.

The objective of this international collaborative study was to compare recent swine isolates of influenza viruses and determine whether significant antigenic differences among isolates from different areas of the world could be detected. H1N1 viruses isolated from pigs, birds and humans in 12 different countries were compared in haemagglutination-inhibition assays with post-infection ferret sera and monoclonal antibodies to H1N1 strains. Using A/NJ/8/76 as the reference strain, we found that recent swine isolates from Hong Kong, Italy, Japan, and the USA possess a haemagglutinin virtually indistinguishable from that of viruses typically associated with pigs, i.e., A/NJ/8/76. In contrast, recent swine isolates from several European countries (Belgium, Denmark, France, Federal Republic of Germany, and Spain) were distinguishable from A/NJ/8/76, as demonstrated by tests in the various laboratories. These studies suggest that the H1N1 viruses in pigs are antigenically heterogeneous and that the circulation of particular variants is associated with the geographical location of the animals. These results raise the question of whether these viruses originated from the same source, i.e., pigs, and have undergone antigenic drift or, alternatively, were introduced from other hosts, such as birds.

Animals↗
PubMed1984

[Evaluation of the incidence of serological cross reactions between Legionella and Mycoplasma or Chlamydia].

Because of the possible serological cross reactions frequently described in the literature between L. pneumophila and M. pneumoniae or between L. pneumophila and Chlamydia, we decided to determine their frequency with our sera and our own methods. The anti M. pneumoniae and Chlamydia antibodies were researched in 162 sera samples from 46 cases of legionellosis serologically diagnosed and in 51 sera from 26 hyperimmunised rabbits. Conversely, anti L. pneumophila antibodies were researched in 165 sera from mycoplasmosis (61) or chlamydiosis (25 cases). None of the sera from mycoplasmosis or chlamydiosis tested by IFA and MA had antilegionella antibodies. None of the rabbits' sera hyperimmunised with Legionella had anti M. pneumoniae or Chlamydia antibodies. On the contrary, by complement fixation and IFA, out of the 46 cases of legionellosis under study, 6 showed a seroconversion in M. pneumoniae and 2 in Chlamydia. The Ig class determination did not show IgM titers in 7 of these 8 sera. The mechanisms of these cross reactions are discussed: antigens and methods used, booster effect during legionellosis, concurrent mycoplasmosis or chlamydiosis.

Agglutination Tests↗
PubMed1984

[Acute necrotizing herpetic encephalitis with a spontaneously improving clinical course].

A 70 year-old-man with recurrent herpetic keratitis had a meningo-encephalitis with transient left hemiplegia and disorders of consciousness. EEG disclosed periodic slow waves on the right temporal region. Isotope and CT scans showed focal abnormalities in the same region. Antibodies to herpes simplex virus were demonstrated by complement fixation in serum and specific antiherpes IgG and IgM by immunofluorescence assay in serum and CSF. A year later the patient had a status epilepticus. CT scan showed a large right temporal hypodense area. CSF was abnormal with pleiocytosis, increased protein and IgG levels. High titers of antiherpes IgG persisted in serum and CSF. Neuropsychological tests did not demonstrate any memory impairment. The occurrence of persistent inflammation after herpes simplex encephalitis is discussed. The unusual benign course without antiviral therapy, may be related to the reactivation of a latent infection with an efficient immunological response. The unilateral temporal necrosis may explain the absence of amnestic sequelae.

Acute Disease↗