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Biomedical subjects

M Aymard

Publications and source records attributed to M Aymard.

At least 163 records · Page 9Linked to original sources
PubMed1980

Isolation and characterization of non-haemagglutinating echoviorus 11.

After multiplication in the continuous human cell lines HeLa, KB, and Hep 2, echovirus 11 (prototype strain Gregory) loses its haemagglutinating (HA) activity but retains infectivity. After seven passages in Hela cells the HA activity was not restored. There was no correlation between the loss of HA activity and modification of thermosensitivity, plaque morphology, surface properties and antigenicity. HA- echovirus 11 particles did not show the properties of defective interfering (DI) particles as described for poliovirus.

Animals↗
PubMed1980

Injections and paralytic poliomyelitis in tropical Africa.

A case-control study was conducted in Yaoundé, United Republic of Cameroon, to evaluate the hypothesis that intramuscular inoculations predisposed young children to paralysis if they were later exposed to poliomyelitis virus. Thirty-three cases with lower motor neuron disease and 66 neighbourhood controls were studied. Poliovirus was isolated from 39% of the paralytic cases but from only 18% of the comparison group. Controls were more likely to have had serological evidence of previous exposure to all three poliovirus types while most of the paralytic cases had been exposed to a poliovirus for the first time. Two-thirds of the paralytic cases but only 11% of the comparison group had been ill, visited a medical facility, and received multiple injections, primarily with quinine and penicillin, in the month prior to the onset of poliomyelitis. There was a strong temporal relationship between these injections and the onset of paralysis. The increased relative risks (15 and 32, respectively) of paralysis associated with inoculations in the two weeks immediately prior to onset of disease were felt to represent the treatment of symptoms related to poliomyelitis. However, the increased relative risks (13 and 27, respectively) three and four weeks prior to onset were felt to be consistent with the hypothesis that intramuscular injections provoked paralysis. Overestimation of this measure of the effect because of bias in the control group is discussed.

Cameroon↗
PubMed1980

[Ocular infection caused by adenovirus 19 (author's transl)].

A case of ocular infection due to adenovirus type 19 is reported. The patient developed a bilateral keratoconjunctivitis with preauricula nodes and a mild general malaise. The virus was isolated from both eyes; serological tests carried out on the serum of the patient were compatible with the diagnosis.

Adenoviridae Infections↗
PubMed1980

[Rapid serodiagnosis of influenza by a modified radial haemolysis test: immune response (author's transl)].

A modification of the single radial haemolysis test by treatment with Cl3Cr of the virus coated red blood cells is proposed for a rapid, more sensitive and reproducible serodiagnosis of Influenza infections. The reagents "red blood cells-virus-Cl3Cr" is stable at 4 degrees C for at least 1 month: the modified test gives results within 3 hours, in measuring the H-anti-H specific reactions. The anti-influenza A immune response was studied in patients of different age, bled at different time after exposure. The IgM do not diffuse in the agarose and do not haemolyse. A clear haemolytic area is produced by IgG, partially haemolysed areas occur when there is a competition between specific IgM and IgG and in the case of reactions involving cross-reacting antigenic determinants.

Adolescent↗
PubMed1979

Selective inactivation of hemagglutinin and neuraminidase on mumps virus.

The thermal stability and the effect of guanidine on the hemagglutinin and neuraminidase of three strains of mumps virus were compared. The heat inactivation of hemagglutinin resulted in the concomitant loss of neuraminidase. The effect of guanidine at various molarities showed that the neuraminidase was more sensitive than the hemagglutinin and a selective inactivation was obtained after exposure to 1.5 M guanidine. However differences in sensitivity of both activities (hemagglutinin and neuraminidase) to heat and guanidine inactivations were observed among strains and correlated with differential susceptibility to non-specific inhibitors of the strains.

Allantois↗
PubMed1979

Study of a new strain of paramyxoviruses isolated from wild ducks: antigenic and biological properties.

Among the different strains of avian paramyxoviruses isolated from migrating feral ducks, two were identified as Newcastle disease viruses (NDV) and the five others would correspond to a new serotype for which we suggest the name of Duck/Mississippi/75 virus. The characteristics of this new serotype are as follows: (1) Duck/Mississippi/75 virus is able to grow as well in allantoic as in amniotic cavities of embryonated hen's eggs; (2) the haemagglutinin and haemolytic activities can be detected with hen red blood cells; (3) the neuraminidase hydrolyses the alpha 2 leads to 3 bonds of the fetuin substrate and its pH activity could be species specific. Antigenically, this serotype is different from all human and animal paramyxoviruses, in spite of an antigenic relationship with NDV.

Animals↗
PubMed1979

Study of a new strain of paramyxoviruses isolated from wild ducks: structural polypeptides.

By polyacrylamide gel electrophoresis, Duck/Mississippi/75 virus was shown to contain five different types of polypeptides of mol. wt. ranging from 76 X 1O(3) to 43 X 10(3), two of which were glycosylated (mol. wt. 76 X 10(3) and 57 X 10(3). A comparison of this data with similar results obtained using Yucaipa and Newcastle disease virus (NDV) revealed a similarity with NDV, concerning the number, position and mol. wt. of the polypeptides. Haemagglutinating and neuraminidase properties are associated with surface glycoproteins which represent at least 40% of the virus protein. After KCl and Triton X-100 treatment and centrifugation on linear sucrose density gradients (10 to 25%, w/w) it was possible to isolate glycoprotein VP1 of mol. wt 76 X 10(3) with which haemagglutinating and neuraminidase activities were associated.

Animals↗
PubMed1979

Antigenic and structural relationships between avian paramyxoviruses isolated from ducks in Hong Kong and Mississippi, U.S.A.

Representative isolates of the paramyxoviruses duck/Hong Kong/75 and duck/Mississippi/75 were shown to be serologically closely related by haemagglutination and neuraminidase inhibition tests. The structural polypeptides of these viruses were also shown to be similar. For each of the isolates tested, polyacrylamide gel electrophoresis in the presence of SDS revealed a similar polypeptide pattern consisting, under reducing conditions, of seven polypeptides with apparent mol. wt. ranging from 46000 to 190000. Each virus had two glycosylated polypeptides with apparent mol. wt. of 56000 and 71000 to 72000 under reducing conditions and 62000 to 63000 and 135000 to 142000 under non-reducing conditions.

Animals↗
PubMed1979

Biochemical properties of paramyxovirus Duck/Mississippi/75 neuraminidase.

The neuraminidase activity of two strains of Duck/Mississippi/75 virus:DK/Mississippi/320 and DK/Mississippi/334 was studied. These neuraminidases hydrolyse the alpha 2 leads to 3 and alpha 2 leads to 8 ketosidic bonds of different substrates such as fetuin, N-acetyl neuramine lactose and colominic acid, but do not hydrolyse the alpha 2 leads to 6 bonds of mucin type I and type II. The kinetic values of the neuraminidases, Michaelis constant, maximal and initial velocities and the effect of pH, temperature and detergents were also evaluated. The isolates differ mainly in the optimal pH and temperature conditions of activity. As with other paramyxovirus neuraminidases, the enzyme of DK/Mississippi/75 was destroyed by ionic but not non-ionic detergents.

Animals↗
PubMed1978

[Transplacental infection by lymphocytic choriomeningitis virus. Results of a retrospective serological study in France (author's transl)].

A study was made on the presence of antibodies against lymphocytic choriomeningitis virus in 452 children in the Lyon area who had suffered from either a major pathological condition or a congenital malformation at birth. Of 34 cases of congenital hydrocephalus, only one could be definitely attributed to a maternal infection with the virus, occurring between the 5th and 6th months of pregnancy. Lymphocytic choriomeningitis virus should thus be added to the list of those which are potentially teratogenic for the human species.

Adult↗
PubMed1978

[Network for the epidemiological survey of the enteroviruses in sewage (author's transl)].

Poliomyelitis still occurs each year in France: 27 cases in 1973, 21 cases in each of 1974 and 1975, 8 cases in 1976. Because of the risk, a survey of the spread of poliovirus in healthy populations and in sewage was organized by the Ministry of Health according to the departmental note DGS/HP/1st/250, 9-2-73. The Laboratoire d'Epidémiologie Virale of the Laboratoire National de la Santé was in charge of the technical aspects of the survey. A preliminary questionnaire was sent to each D.D.A.S.S. (Direction Départementale de l'Action Sanitaire et Sociale) in order to find out the local possibilities for sampling and preliminary treatment of the sewage samples. In 1974, all the samples were sent to the Laboratoire d'Epidémiologie Virale. Since 1975, samples have been sent to a local virology laboratory when available. The sewage samples were concentrated according to SHUVAL's or LUND's methods depending on the local conditions. Both methods tested in our laboratory were found equally efficient. In order to improve their technical laboratory methods, the virologists collaborating in this survey joined together in a working group "Virus et Eaux". For isolating the enteroviruses, we recommend the inoculation of each concentrated sample into primary monkey kidney cells grown in vials; an overlay of agar is added after inoculation. This plaque method allowed us to isolate several strains from one sample. It was possible to demonstrate that polioviruses differing in serotypes and thermosensitivity might be detectable in the same sample. Few of the isolated polioviruses (11/272) showed the same thermoresistance as did the wild strains. Certain enterovirus serotypes are known to be responsible for epidemics of meningitis and neurological disorders. It was of interest to identify non-poliomyelitic enteroviruses isolated from sewage. The study of enterovirus spread in sewage in comparison with that in healthy children is in progress.

Animals↗
PubMed1978

[Surveillance of influenza in France (author's transl)].

The collection of data for influenza surveillance is difficult because clinical cases cannot easily be notified by practitioners and because only a few cases are studied by specific biological methods. In different countries, several indices are used such as: morbidity returns, mortality returns, absenteeism returns preferably in combination. In France, the two National Reference Centres in Paris and Lyon coordinate the activities of all diagnostic laboratories where influenza is detected by collecting and redistributing their findings and by identifying the strains they isolate. Furthermore, a collaborative network of physicians and institutions is being organised to provide a complete coverage of the country. I.N.S.E.R.M. and the National Centres have set up during the last two winters a new method of specific surveillance in school children: it combines observation of absenteeism peak in randomly selected classes and etiologic diagnosis by virus isolation. Surveillance of such a group, particularly sensitive to epidemic spread and probably partly responsible for it, was very efficient: early isolations were obtained and the presence of epidemics was detected before overt outbreaks occurred.

Absenteeism↗
PubMed1978

Poliomyelitis survey in Middle-East countries.

The poliomyelitis survey was started in 1976 in Bahrain and Kuwait. For each paralytic case, diagnosis was done by virus isolation, neutralizing antibody titration and specific IgM characterization. More than 90% of the infants who were ill were less than 2 years old. In Bahrain, 17 paralytic cases in 1976 and 12 in 1977 occurred between January and July (annual incidence was respectively 7.7 and 5.4/100,000). The first epidemic was due to poliovirus type 2, the second one to poliovirus type1. From 29 cases, 13 occurred in vaccinated infants of which 9 received 3 or 4 oral vaccine doses. For 3 infants, paralysis occurred less than one month after vaccination. All the isolates were wild polioviruses (rct). In Kuwait, 119 cases were examined, and of them, 57 occurred between August 76 and May 77 (incidence 5.7/100,000). Poliovirus type 1 was responsible for 61% of cases, type 2 for 5% and type 3 for 12%. From October 1976 to December 1977, 350 stools samples were collected from contacts: 19% of them carried poliovirus (12% type 1, 1% type 2 and 6% type 3). All the viruses isolated from both paralytic cases and contacts were wild strains (rct). Of 119 cases, 35 occurred in vaccinated infants from which 4 had received 3 or 4 oral vaccine doses. For 11 infants paralysis occurred less than one month after vaccination. The virus spread was evaluated (i) just before vaccination in 337 infants or children from June to December 76: 8% carried poliovirus Sabin-like strains (and 18% non polioviruses), and (ii) one month after vaccination in 75 infants: 37% carried poliovirus Sabin-like strains.

Adolescent↗