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Biomedical subjects

P Coursaget

Publications and source records attributed to P Coursaget.

At least 19 recordsLinked to original sources

Comparative immunogenicity in children of mammalian cell-derived recombinant hepatitis B vaccine and plasma-derived hepatitis B vaccine.

Three doses of hepatitis B vaccine were given at 2, 4 and 9 months of age to 220 Senegalese infants living in the Dakar area of Senegal. Half of the infants received 5 micrograms plasma-derived hepatitis B vaccine (Hevac B) and the remainder 20 micrograms mammalian cell-derived recombinant hepatitis B vaccine (GenHevac B). Both vaccines contain S and pre-S2 encoded proteins; however, the recombinant vaccine had a much higher pre-S2 content than the plasma-derived vaccine. Adverse reactions to both vaccines were limited to mild and transient soreness at the injection site. Fever was reported in 14-21% of the infants and was likely to be related to DTP-polio vaccine which was given simultaneously. After the two first doses, seroconversion rates and geometric mean titres of anti-HBs were higher in infants receiving the recombinant vaccine than in infants receiving the plasma-derived vaccine. After completion of vaccination, all infants in both groups had protective levels of anti-HBs antibodies. The recombinant vaccine induced more rapidly antibodies directed against S and pre-S2 epitopes. Anti-pre-S2 antibodies were detected after the first injection of GenHevac B and only after the third injection of Hevac B. From the data, GenHevac B vaccine is expected to be as effective as Hevac B vaccine for controlling hepatitis B infection.

Amino Acid Sequence

Simultaneous injection of hepatitis B vaccine with BCG and killed poliovirus vaccine.

In most developing countries, hepatitis B virus is endemic and prevention has to be carried out early in life and on a mass scale. In these regions, simultaneous administration of multiple antigens is normal practice. We have therefore investigated the interaction of hepatitis B vaccine with BCG and inactivated polio vaccine. The serological antibody response to poliovirus and HBsAg as well as the cellular immune response to tuberculin post BCG immunization were assessed. The immune responses to HBsAg, BCG and polio vaccines injected simultaneously were comparable to those observed after separate administration of each vaccine. Moreover, no increase of adverse reactions was noted. Results confirmed that HB vaccine could be introduced into the WHO expanded programmes on immunization without impairing the expected protective efficacy against the targeted vaccine-preventable diseases.

BCG Vaccine

Hepatitis C core antibody detection in acute hepatitis and cirrhosis patients from Tunisia.

The detection of anti-Hepatitis C virus (HCV) Core antibodies is an important addition to HCV antibody testing. In this study it appears to be more specific than the first generation HCV tests and in combination with the detection of anti-C33c antibodies, it is possibly more sensitive. In Tunisia hepatitis C virus is implicated by the presence of anti-Core antibodies in only 8% of the adult cases of acute hepatitis as opposed to 60% for Hepatitis B virus (HBV) and 4% for Hepatitis A virus (HAV). In contrast to the low prevalence of HCV infection among acute hepatitis cases, HCV infection is implicated in 35% of the cirrhosis cases. These results stress the potential importance of HCV infection in the development of cirrhosis which is a relatively common disease in North Africa.

Enzyme-Linked Immunosorbent Assay

Detection of hepatitis B virus DNA by polymerase chain reaction in HBsAg negative Senegalese patients suffering from cirrhosis or primary liver cancer.

The polymerase chain reaction was used to search for hepatitis B virus (HBV)-DNA sequences in the sera of HBsAg-negative Senegalese patients suffering from liver cirrhosis or liver cancer. Amplified HBV-DNA sequences were detected by hybridization with a digoxigenin-labelled HBV-DNA probe. HBV-DNA was detected in 17% of HBsAg negative Senegalese subjects from the general population and in 44% and 58% of the patients suffering from cirrhosis or primary hepatocellular carcinoma (PHCC) respectively. In the control group, amplified HBV-DNA was detected in 25% of the subjects without HBsAg and anti-HBs antibodies, and in 6% of subjects positive for anti-HBs antibodies. This study confirmed the hypothesis that there is an etiologic link between HBV and PHCC in HBsAg-negative patients.

Base Sequence

Scheduling of revaccination against hepatitis B virus.

Studies have shown that to maintain protection against infection after a primary course of hepatitis B immunisation, revaccination can be scheduled on the basis of an anti-hepatitis B virus surface antigen (anti-HBs) titre obtained 1 month after the booster dose. However, schemes which require post-booster testing may present practical difficulties. We applied a random-effects regression model to data from 118 Senegalese infants given three injections of hepatitis B vaccine about 6 weeks apart and a booster injection at 13 months, and show that revaccination can be scheduled on the basis of an anti-HBs titre recorded at the time of the booster dose. We also show that titre-at-booster is no less accurate in predicting future titre than 1-month post-booster titre. In several other studies the post-booster decline in anti-HBs conforms to the same mathematical description, indicating the generality of our findings.

Hepatitis B

Determination of circulating antibodies directed to pertussis toxin and of agglutinogens in children vaccinated with either the whole cell or component pertussis vaccine in France, Japan and Senegal.

The antibody response to pertussis toxin (PT) and agglutinogens of children vaccinated in Japan, France and Senegal with either whole cell or component pertussis vaccine was determined at various times after immunization. Agglutinin titres were almost similar in sera of Japanese children vaccinated with either whole cell or component pertussis vaccine whereas anti-PT antibody levels were found to be higher after vaccination with whole cell vaccine than with component vaccine. The geometric mean (GM) agglutinin titres in sera of Japanese children amounted to 45.0 and 45.7, respectively, and neutralization GM titres to 71.6 and 22.6, respectively, following vaccination with the whole cell and component pertussis vaccines. Sera of French children receiving three doses of whole cell vaccine exhibited a GM agglutinin titre of 17.8, whereas only 16% of sera contained neutralizing antibodies against PT. Following the booster dose the GM agglutinin titre rose to 213.5 and 68% of the sera contained neutralizing antibodies to PT (GM titre 48.0). Sera of Senegalese children receiving three doses of whole cell vaccine exhibited a GM agglutinin titre of 18.7, whereas anti-PT neutralizing antibodies were hardly detected. Agglutinins and anti-PT antibody in sera of French and Senegalese children turned out to be lower than were found 25 years ago in sera of children immunized with the French whole cell pertussis vaccine.

Adolescent

Incidence of hepatitis C virus infection in burn patients: detection of anti-C100, anti-C33c and anti-Core antibodies.

Anti-hepatitis C virus antibodies were searched for in 45 burnt patients, at the time of burn injury and more than 6 months after burn injury. HCV infection was detected in 18% as a consequence of the numerous transfusions of blood or blood derivatives used during the post-burn treatment. Five patients displayed evidence of anti-C100, anti-C33c and anti-Core antibodies together; two patients had only anti-C100 and anti-C33c antibodies, and the last one showed only anti-Core antibodies. Chronic hepatitis was observed in 83% of HCV infections. Kinetics of appearance of anti-HCV antibodies varied between patients. Anti-Core is generally the first to be detected at high levels; however, in at least one case it was detected only two and a half months after C100 and C33c antibodies.

Alanine Transaminase

[Detection of human type 16 papillomavirus in epithelial cells of the uterine cervix].

Cervical cells obtained by scraping from 126 women living in the Tours area, France, were tested for the presence of HPV 16 infection, using the PCR method. In all samples analysed no evidence was found of HPV 16 b subtype. The incidence of HPV 16 infection ranged from 4% in women without history of genital HPV infection to 48% in women with high-grade squamous intraepithelial lesions (SIL). It must be noted that HPV 16 infection is twice as frequent in women with a history of HPV-induced cervical lesions as in those without this history. Thus, a normal cytology does not always mean an absence of HPV infection of the uterine cervix. It may be concluded from these results that detection of cervical HPV 16 infection by the PCR method makes it possible to identify a group of women at high risk of developing SIL or cervical cancer. Regular cytological surveillance of these women who are healthy carriers of HPV 16 without detectable squamous cell abnormalities must be implemented.

Female

Hepatitis B virus antigens in human primary hepatocellular carcinoma tissues.

The presence of hepatitis B virus (HBV) antigens was examined in specimens of liver tissue obtained at necropsy from black Senegalese patients suffering from primary hepatocellular carcinoma (PHC). The results were correlated with markers of hepatitis B infection in serum. Hepatitis B surface antigen (HBsAg) and core antigen (HBcAg) were sought for in 15 liver extracts. HBsAg was found in the liver in 10 of 12 cases with HBsAg-positive serum. HBcAg was detected in three livers. The HBsAg was detected in seven of eight livers by immunofluorescence and orcein staining. HBsAg-positive cells were mainly located in the peri-tumoral cirrhotic tissue, although positive hepatocytes were also found in tumour nodules in liver from one of the patients. HBcAg was found in five of seven cases by immunofluorescence in hepatocytes of the cirrhotic areas. HBcAg fluorescence was primarily nuclear but, in some lobules, a patchy cytoplasmic fluorescence was observed. This suggests a cytoplasm-nucleus pathway in the synthesis of the HBV core antigen. Electron microscopy was performed on two HBsAg- and HBcAg-positive cases. Fibrillar and crystalline cytoplasmic inclusions were observed in tumour cells. In the same cells, 20-25 nm virus-like particles were present in swollen cisternae of the endoplasmic reticulum.

Adult

[Hepatitis A of children. Seroepidemiological study among French urban population (author's transl)].

A prevalence survey of hepatitis A antibody (anti-HAV) was conducted among 145 children living in the area of Tours (France). Thirty-four per cent of children's sera was found anti-HAV positive when tested by both immune adherence hemagglutination assay (IAHA) and specific radio-immunoassay (RIA). The prevalence of anti-HAV among infants less than one year and children between 1 to 5 years, was 35 per cent and 15 per cent respectively. From 6 years old, the prevalence of anti-HAV increased abruptly and reached 47 per cent in the 11 to 15 age group. Anti-HAV titers as measured by IAHA also increased according to age. In this study, the prevalence of anti-HAV was not related to sex, history of past surgery and/or blood transfusions. Only 12 per cent of children with anti-HAV positive test had history of jaundice. These results show that, in France, primary contact with hepatitis A virus (HAV) appear early in childhood, at school age, and that in children more than 80% of HAV infections remain asymptomatic.

Adolescent

[The hepatitis B virus markers, in leprous patients (author's transl)].

The hepatitis B virus markers were studied on 553 leprous sera and 100 controls sera. HBs Ag detected by RIA were present on 25,4% of leprous and 12% of controls; the anti-HBs by RIA were revealed in 44,1% of patients out 38% of controls. The leprous was not carrying this markers were HBe Ag or anti-HBe or anti-HBc positive. By this vertical study it appears that 2,4% of the cases presented recent or acute hepatitis; 23% were chronic carriers; 41,7% had been in times past infected but were cured and the third remaining had been infected but coat markers were absent, it is more than likely that is an old infected group. The study revealed no significant difference in hepatitis chronic forms frequency between lepromatous and tuberculoïd patients.

Adult

Serologic response in human hepatitis A: detection of antibody by radioimmunoassay and immune adherence hemagglutination.

An indirect solid-phase radioimmunoassay (RIA) for detection of antibody to the hepatitis A antigen (anti-HAV) was developed using polystyrene pearls as the solid phase and hepatitis A antigen (HAAg) extracted from marmoset livers. This RIA was compared to an immune adherence hemagglutination assay (IAHA) which employed HAAg derived from the stools of chimpanzees collected during acute hepatitis A. Anti-HAV was detected in the sera of 15 humans with naturally acquired hepatitis A infection. Sensitivity and specificity were greater using the RIA, permitting the detection of anti-HAV as early as the time of onset of jaundice. Either seroconversion or a significant increase in the titer of anti-HAV was demonstrated following hepatitis A exposure in paired sera from six patients by both techniques. No significant difference in anti-HAV responses was noted between patients with icteric compared to anicteric hepatitis A or between children and adults with hepatitis A.

Adolescent

Hepatitis A infection and primary hepatocellular carcinoma.

The prevalence of antibody to the hepatitis A antigen (anti-HAV) has been studied in Senegal, among patients suffering from primary hepatocellular carcinoma (PHC) and among healthy blood donors. Anti-HAV was found in 62.5% of 64 cases of PHC as compared to 64% of 50 blood donors. Anti-HAV was as prevalent among PHC patients who evidenced chronic hepatitis B infection as among those without markers of chronic hepatitis B infection. These data suggest that hepatitis A infection is not associated with PHC in Senegal.

Adult

Vaccine against hepatitis B--18 months prevention in a high risk setting.

The development of a vaccine against hepatitis B prepared with purified and inactivated HBs Ag is described. This vaccine has been applied in patients and staff members of haemodialysis centres. Safety and efficiency of the vaccine are very satisfactory. The response of patients to immunisation was significantly lower compared to the response of the staff members. None of the volunteers who had a primary response to immunisation developed signs of clinical or biological hepatitis.

Hepatitis B

HBsAg-negative chronic active hepatitis related to hepatitis B virus.

Numerous cases of chronic hepatitis have been shown to be closely associated with persistent infection with hepatitis B virus (HBV). A group of 100 patients suffering from chronic active hepatitis (CAH) was investigated for HBV serologic markers. Of these, 35 patients were HbsAg-positive; in 26 HBsAg-negative subjects, anti-HBc were detected using counterimmune electrophoresis and complement-fixation tests. These data suggest that chronic liver disease in patients who were only anti-HBc-positive might be related to persistent infection with hepatitis B virus. Epidemiological clinical and histopathological data were different when we compared CAH patients who were HBsAg-negative, but anti-HBc-positive, with HBsAg-positive CAH patients. A sequence is proposed leading from HBsAg-positive to HBsAg-negative CAH, cirrhosis, and hepatoma in temperate areas, according to a model similar to the one described in intertropical Africa.

Adolescent

Antibody to hepatitis B core antigen in chronic active hepatitis.

Antibody to hepatitis B core antigen (anti-HBc), which has been assumed to be a more sensitive indicator of hepatitis B virus replication than hepatitis B surface antigen (HBsAg), was detected in the sera of 26 of our 65 patients with HBsAg-negative chronic active hepatitis. Thus despite the absence of HBsAg the liver disease could be the consequence of chronic infection with hepatitis B virus in these patients. They differed, however, from a group of 35 patients with HBsAg-positive hepatitis in being older on average and having less active liver lesions. The two groups could represent either two stages of chronic infection with hepatitis B virus or two types of response to it.

Adolescent