Search PubMed⌕ Search

Biomedical subjects

N Masurel

Publications and source records attributed to N Masurel.

At least 91 records · Page 5Linked to original sources

Recycling of H1N1 influenza A virus in man--a haemagglutinin antibody study.

Sera from people born between 1883 and 1930 and collected in 1977 were tested for the presence of HI antibodies to A/FM/1/47 (H1N1) virus and three recently (1977 and 1978) isolated influenza A-H1N1 viruses. The highest frequency of high-titred antibody to the four H1N1 viruses was detected in sera from people born in 1903-4, i.e. 42, 54, 38, and 22% had antibody against A/FM/1/47, A/Hong Kong/117/77, A/Brazil/11/78, and A/Fukushima/103/78 respectively. The birthdate groups 1896-1907 showed a higher percentage of HI antibody titres greater than or equal to 18, greater than or equal to 50, greater than or equal to 100 or greater than or equal to 1600 against the four H1N1 viruses than the birthdate groups 1907-30. This indicates the existence of an era, 1908-18, in which, apart from the H3N2 virus (1900-18), the H1N1 virus was epidemic among the human population.

Age Factors↗

Co-occurrence of HBsAg and anti-HBs: two consecutive infections or a sign of advanced chronic liver disease?

Simultaneous presence of hepatitis B surface antigen (HBsAg) and antibodies to the surface antigen (anti-HBs) was detected in 32 out of 89 Dutch chronic hepatitis patients of Caucasian race. HBsAg was subtyped ad in 28 and ay in four cases. Anti-HBs could be subtyped in 25 cases using reference antigens discriminating between d, y, and w1-4 subdeterminants. In 20 patients HBsAg subtype ad (HBsAg/ ad) was accompanied by antibody to subdeterminant y (anti-y), whereas HBsAg/ ay and anti-d were simultaneously detected in the serum of one patient. The antibody pattern in sera from the remaining patients was complex. Eighteen anti-HBs-positive patients were matched for age, histology, and hepatitis B e antigen (HBeAg) status with 18 anti-HBs-negative patients. Differences in risk factors for acquiring a hepatitis B infection were not found. These results do not support the hypothesis that co-occurrence of HBsAg and anti-HBs is due to two consecutive infections with hepatitis B virus. The frequency of the co-occurrence of HBsAg and anti-HBs was found to be related to the degree of progressive liver disease, since anti-HBs was found in three out of 23 asymptomatic carriers, in four out of 20 chronic persistent hepatitis patients, in 20 out of 41 chronic active hepatitis patients, and in all five patients with chronic active hepatitis and cirrhosis. The high frequency of anti-HBs in advanced liver disease may be the result of a disturbed immunologic response mechanism.

Antibodies, Viral↗

Antibody response to immunization with influenza A/USSR/77 (H1N1) virus in young individuals primed or unprimed for A/New Jersey/76 (H1N1) virus.

A group of 269 pupils of the Harbour and Transport Training Institute in Rotterdam (group A), aged 13-20 years, and of 109 patients of the Dr Mr Willem van den Bergh Foundation at Noordwijk (group B), aged 11-21 years, were immunized with a whole virus vaccine containing 10, 20, or 40 microgram HA of A/USSR/92/77 (H1N1) influenza virus. A booster vaccination was administered 6 weeks later with 20 microgram HA of the same virus. Many of the participants had been immunized during the two preceding years with a whole virus vaccine containing A/New Jersey/8/76 (H1N1) (A/NJ/76) virus. The side-effects, mostly of a moderate nature, increased with the dose of virus in the vaccine. In group A side effects were least frequent in the vaccinees who had never received A/NJ/76 vaccine. A single dose of A/USSR/77 vaccine did not produce satisfactory levels of homologous antibodies. After booster immunization with 20 microgram HA of A/USSR/77 virus participants showed a higher homologous antibody response in all vaccine-dose groups if they had not been immunized with A/NJ/76 virus in previous years. After primary and especially after booster immunization with A/USSR/77 virus, a very high response against A/NJ/76 virus and adequate levels of A/NJ/76 antibody were found in participants who had been immunized previously with A/NJ/76 virus. Those who had not been immunized with this virus previously showed no or a very low antibody response to A/NJ/76 virus.

Adolescent↗

Equine influenza in the Netherlands during the winter of 1978-1979; antigenic drift of the A-equi 2 virus.

Influenza virus A-equi 2(Heq2Neq2) caused an epizootic in the Netherlands in the winter of 1978-1979. Horses vaccinated with A/Equi/Praha/56 (HEq1Neq1) and A/Equi/Miami/63 (Heq2Neq2) were also infected and showed clinical signs. The virus involved showed a marked antigenic drift from the prototype and vaccine strain A/Equi/Miami/63 (Heq2Neq2). Infection of ferrets with the Dutch/79 isolates gave rise to high haemagglutination-inhibition antibody titres to a number of A-Equi 2-1963, 1968 and 1979 viruses. The incorporation of this virus into future influenza vaccines should be considered.

Animals↗

Double-blind study of leucocyte interferon administration in chronic HBsAg-positive hepatitis.

In a double-blind study human leucocyte interferon was given for six weeks to 8 of 16 patients with chronic HBsAg-positive hepatitis. In the first week 12 x 10(6) reference units were administered daily, and thereafter the dose was halved every week. During the first two weeks leucopenia was observed in 6 of the 8 interferon-treated patients. Apart from a drop in DNA-polymerase activity in the first week, no effect was found on indices of hepatitis-B-virus infection.

Adult↗

Quantitative relationship between HBeAg and DNA polymerase activity in sera from patients with chronic active hepatitis during a three-month period.

In eight patients with biopsy-confirmed chronic active hepatitis (CAH), hepatitis B e antigen (HBeAg) levels and DNA polymerase (DNA-P) activity were assayed three times a week for six weeks and once a week for another six weeks. HBeAg levels were rather constant, whereas DNA-P activity fluctuated. No correlation was observed between the quantities of HBeAg and DNA-P activity. An unexpected fluctuation in DNA-P activity was noted in all patients after an influenza vaccination.

Chronic Disease↗

Influenza vaccination in HBsAg positive chronic active hepatitis patients treated with interferon.

Sixteen patients with hepatitis B antigen (HBsAg) positive chronic active hepatitis (CAH) were vaccinated with the nonhuman influenza A virus Heq1Neq1; eight patients were also treated with leucocyte interferon. Pre-vaccination sera were negative for specific antibody in hemagglutination inhibition tests. Four weeks after vaccination all patients had responded with a homologous antibody titer. Between the interferon-treated and the untreated groups the differences in antibody titers against the vaccine virus were not significant. Concomitant with the antibody response against the nonhuman influenza virus, a fourfold or higher antibody rise was observed against the influenza A virus strains Hsw1N1 (in six treated with seven untreated patients), H1N1 (in six treated and four untreated patients) and H3N2 (in five treated patients only). The results suggest that a normal specific antibody response in HBsAg positive chronic active hepatitis patients is not significantly altered by leucocyte interferon, and that non-specific antibody production can occur in the absence of a serologic relationship.

Adult↗

Haemagglutination-inhibition antibodies against influenza A and influenza B in maternal and neonatal sera.

Haemagglutination inhibition (HI) antibodies against the influenza viruses A/Hong Kong/8/68 (H3N2) and B/Nederland/77/66 were determined in 420 paired sera from mothers and newborns (umbilical cord sera), sampled in 1970-1. A higher concentration of antibodies against influenza A virus was found more frequently in neonatal than in maternal sera. By contrast, low titres against influenza B virus were more frequently observed in neonatal than in maternal sera. Maternal age, duration of pregnancy, and birth-weight did not affect the results of the tests. It is suggested that the titre of the newborn against an epidemic influenza virus can be predicted from that of the mother. Furthermore, the maternal titre may be an indication of the susceptibility of the newborn infant to influenza infections.

Adolescent↗

Double-blind study of interferon administration in renal transplant recipients.

In a double-blind trial renal allograft recipients were treated with fibroblast interferon preparations for 3 months in an attempt to prevent viral infections. Interferon therapy did not reduce the overall incidence of viral infections. No adverse effects were noted on liver function, platelet counts, or leucocyte counts, or acute rejection episodes.

Adolescent↗

Cross-protection in mice after immunization with H2N2, H3N2, and Heq2Neq2 influenza virus strains.

Mice were vaccinated with the influenza viruses A/Japan/57 (H2N2), A/Hong Kong/68 (H3N2), and A/Equi/Miami/63 (Heq2Neq2) and the hemagglutinin and neuraminidase recombinants derived from these viruses. After infection with the parent viruses, protection was compared with serological findings. It was found that influenza vaccine protects not only against infection with a strain identical or closely related to the vaccine strain, but against heterologous strains as well. Vaccination with Hong Kong/68 and its neuraminidase recombinant resulted in a heterologous neuraminidase inhibition titer against Japan/57 and in a protection against infection with Japan/57. By contrast, after vaccination with Japan/57 and its neuraminidase recombinant, no relevant heterologous neuraminidase inhibition titer against Hong Kong/68 was observed, whereas a protection against infection with Hong Kong/68 did exist. A cross-protection between Hong Kong/68 and Miami/63, but no relationship in the hemagglutination or neuraminidase inhibition tests, was established in the preinfection sera. A one-way antigenic relationship between these viruses was confirmed by the rise of hemagglutinin or neuraminidase antibodies against Hong Kong/68 in the postinfection sera. No cross-protection or serological relationship existed between Miami/63 and Japan/57. Besides the hemagglutinin and neuraminidase, a third factor, the "mouse-protecting antigen," was considered to contribute to the protection obtained. According to the protection observed, the mouse-protecting antigen of Hong Kong/68 virus is related to that of Japan/57 as well as Miami/63 virus. The mouse-protecting antigens of both Japan/57 and Miami/63 are related to that of Hong Kong/68.

Animals↗

Agents affecting health of mother and child in a rural area of Kenya. X. Haemagglutination inhibiting antibodies against influenza A (H3N2) and influenza B virus in sera from children living in the Machakos District of Kenya.

In the framework of the Machakos Project bloodcollections from random samples of children under 5 years of age and living in a rural area of Kenya were done with regular intervals, Serum samples of two collections were tested for haemagglutination inhibiting antibodies against influenza A and B viruses. The children had been exposed to the Hong Kong/1/68 (H3N2) virus or its variants during one, two or three episodes of circulation and probably to only one epidosde of B/Hong Kong/8/73 virus. The results can be explained by the assumption that 30-40 percent of non-immune children were infected per epidosde of exposure to influenza A and not more than 12 percent per episode of influenza B circulation.

Antibodies, Viral↗