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Biomedical subjects

N Masurel

Publications and source records attributed to N Masurel.

At least 73 records · Page 4Linked to original sources
PubMed1985

Comparison of two techniques for detecting antibody to HBsAg during a hepatitis B vaccine study.

Two assays for the detection of antibody against hepatitis B surface antigen (anti-HBs) were compared. The first was a direct sandwich radioimmunoassay (RIA) which detects, in principle, antibody against any epitope of hepatitis B surface antigen (HBsAg). The second assay was an inhibition enzyme-linked immunosorbent assay (ELISA). In this assay a fixed amount of HBsAg which can be blocked by anti-HBs is measured in a direct sandwich test. Prevaccination screening sera (n = 191) and follow-up sera obtained from high risk groups (n1 = 85; n2 = 41) during two hepatitis B vaccine studies were compared in RIA and ELISA. In prevaccination sera either HBsAg or anti-HBs were detected by ELISA. Full agreement between the results of RIA and ELISA for anti-HBs was obtained in sera containing more than 10 IU/l anti-HBs. Both tests showed variable results at low titres. Experiments with monoclonal anti-HBs indicated that ELISA is less sensitive for subtype specific antibodies (anti-d, anti-y), which may explain that there were consistent differences between RIA and ELISA in a minority of cases.

Antibodies, Monoclonal↗
PubMed1985

Antigenic heterogeneity among influenza A(H3N2) field isolates during an outbreak in 1982/83, estimated by methods of numerical taxonomy.

Fourteen influenza A(H3N2) field isolates, mainly obtained during the first weeks of the 1982/83 influenza epidemic in The Netherlands, and nine influenza A(H3N2) reference strains were examined by means of haemagglutination inhibition (HI) tests with 23 polyclonal ferret sera. The resulting HI patterns were subjected to various methods of numerical taxonomy using, among others, taxonomic distance and correlation between strains for resemblance coefficients. Marked differences between distance and correlation coefficients were found in strains which differed in avidity only. The field isolates could be divided into four groups in respect of their taxonomic resemblance to the reference strains. The same grouping was found for five of the field isolates by testing these against 200 human sera.

Animals↗
PubMed1984

A one-year study of trivalent influenza vaccines in primed and unprimed volunteers: immunogenicity, clinical reactions and protection.

Three hundred volunteers were divided into two age groups, 14-30 years and 31-60 years. Each participant was immunized intramuscularly with a subunit, whole virus or absorbed whole virus vaccine, containing A/Bangkok/1/79 (H3N2), A/Brazil/11/78 (H1N1) and B/Singapore/222/79 influenza virus. Serum haemagglutination-inhibition (HI) antibody response, protection, and reactogenicity were studied after one and two doses of the vaccines. Primary immunization induced much higher percentages of HI antibody titres greater than or equal to 100 against all three vaccine viruses and much higher geometric mean titres (GMT) in volunteers with pre-immunization titres greater than or equal to 18 as compared to those with pre-immunization titres less than 18. Secondary immunization did not result in an increase of GMTs or antibody titres greater than or equal to 100 in volunteers with pre-immunization titres less than 18. On the whole, the response to the subunit vaccine was similar to that to the other two vaccines. To influenza B/Singapore/222/79 virus the response was lowest after administration of the whole virus vaccine in the age group 31-60 years. Over 50% of the HI titres greater than or equal to 100 found after immunization in the different vaccine and age groups were still present after one year. Serologically established infections during the winter months following immunization amounted to 15% in the subunit vaccine group, 6% in the whole virus vaccine group, and 10% in the adsorbed whole virus vaccine group. Local and systemic reactions to all three vaccines were mild in nature. Local reactions after primary immunization were much less frequent following administration of the subunit vaccine as compared to the other two vaccines, especially in the younger age group. In comparison to primary immunization, after booster immunization the incidence of local reactions was higher for the subunit vaccine and lower for the adsorbed whole virus vaccine. In the age group 14-30 years the incidence of local reactions after primary as well as booster immunization was much greater in females than in males, especially when the adsorbed whole virus vaccine was used.

Adolescent↗
PubMed1984

Hepatitis B antigen and antibody in the blood of prostitutes visiting an outpatient venereology department in Rotterdam.

We took blood samples from 128 prostitutes visiting the outpatient venereology department of the University Hospital, Rotterdam-Dijkzigt to test for the presence of hepatitis B surface antigen (HBsAg) and antibody to hepatitis B surface antigen (anti-HBs). The prevalence of anti-HBs was found to be significantly higher in the group of prostitutes than in "normal populations", and we concluded that more of the former had been in contact with the hepatitis B virus (HBV). We recommend that the advice on vaccination of the hepatitis B committee of the Health Council of The Netherlands should be followed by screening prostitutes for the presence of HBsAg and anti-HBs in the blood, and vaccinating those who have no anti-HBs.

Adolescent↗
PubMed1983

Measles in Tanzania: antibody response in children after vaccination and antibody state of mothers and newborns.

The antibody response to attenuated live measles vaccines was studied in two groups of 29 (A) and 53 (B) African children. In group A 22 sera and in group B 34 sera showed no pre-immunization haemagglutination inhibition (HI) titres. Vaccination resulted in seroconversion in 64 and 85% of groups A and B, respectively. The difference in antibody response between the two groups could be traced to children in the age group seven to eight months, where seroconversion was absent in 67% of group A children and in 0% of group B children. Antibody levels were studied in 234 mothers and their newborns. In 131 serum pairs the antibody levels of mother and child were similar. 78 (33%) of mothers showed a higher titre and 25 (11%) a lower titre than their babies. All newborns except one and all mothers except one possessed antibody titres above 10. Children in the age groups seven to eight months and nine to ten months showed antibody in 12 and 7%, respectively. Over 90% of these children had not been infected in the first ten months of life.

Adolescent↗
PubMed1983

Prevalence of influenza viruses A-H1N1 and A-H3N2 in swine in the Netherlands.

In the period December 1979-May 1980 a respiratory disease spread rapidly through pig herds in The Netherlands. Surveillance of 12 pig farms resulted in isolation of 22 influenza A-Swine-H1N1 (Hsw1N1) strains from 9 pig herds. The morbidity rate was high but the mortality rate was nil. Retardation in growth was observed. Sera collected from affected pig herds showed a fourfold increase in haemagglutination inhibition (HI) titre against A-Swine-H1N1 virus. Sera collected on five farms showed a geometric mean HI titre against the A-H3N2 virus above 100. A significant HI titre increase against this virus was found in sera collected on three farms. These findings indicated a recent infection by this virus. A-H3N2 virus was not isolated. The Dutch Swine-1980 isolates showed in the cross-HI test a distant antigenic relationship with the classical A/Swine/Iowa/30 (H1N1) virus and one-sided close antigenic relationship with A/New Jersey/76 (H1N1) virus. HI antibody to A/Swine/Nederland/80 (H1N1) virus was found in 4, 0, and 44%, to A/New Jersey/76 (H1N1) virus in 0.5, 0.4, and 42%, and to A/Swine/Iowa/30 (H1N1) virus in 0.5, 1, and 30% of pig sera collected in 1976, 1977, and 1980, respectively. HI antibody to A/Hong Kong/68 (H3N2) virus was detected in 36, 56, and 68%, and to A/Victoria/75 (H3N2) virus in 38, 73, and 68% of these sera, respectively. The results of this study indicate that pigs in The Netherlands, like those in North America, Southeast Asia, Japan, and Western Europe harbour A-Swine-H1N1 and A-H3N2 influenza viruses and are thus potential reservoirs for future human pandemics.

Animals↗