A simplified plaque technique for titration of pox virus and its antibodies in chick embryo cells.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
S O Larsen
Publications and source records attributed to S O Larsen.
Examination for tubercle bacili by fluorescence microscopy.
Explore the source record for details and available documents.
Microscopy, Fluorescence↗
International collaborative assay of the international reference preparation of anti-yellow-fever serum.
A yellow fever immune serum was established in 1962 by the WHO Expert Committee on Biological Standardization as the International Reference Preparation of Anti-Yellow-Fever Serum, intended to serve as an immune reference serum in the mouse protection test used in the control of yellow fever vaccines.Before its establishment as the International Reference Preparation, the proposed material was assayed in eleven laboratories in ten countries against a number of other immune and non-immune sera, and was found stable. Neutralization test results were consistent and the relative potency was sufficiently high. This paper not only reports on the collaborative assay, but also discusses errors in the testing method and problems connected with the distribution of mouse deaths during the observation period and with the preparation of dilutions.
Biological Assay↗
Laboratory toxicity test of field trial typhoid vaccines.
It is important for the control of vaccines to develop methods for testing their toxicity in the laboratory. Two typhoid vaccines that had given different rates of reactions among vaccinated persons in extensive field trials provided a unique opportunity for exploring the validity of the laboratory assessment of their toxicity. An elaborate design of a toxicity test based on weight changes in intraperitoneally vaccinated mice is described in this paper. The results of the laboratory test reflected the experience gained in field studies.
Animals↗
Differential antibody response of Gambian donors to soluble Plasmodium falciparum antigens.
A seroepidemiological and clinical study was performed in an area of West Africa (The Gambia) where Plasmodium falciparum is endemic with seasonal transmission. Plasma samples were tested by intermediate gel immunoelectrophoresis for antibodies against 7 soluble P. falciparum antigens. There were marked differences in the age-related pattern of antibody response to the different antigens. Antibodies to 4 of the antigens were acquired slowly with a maximum prevalence reached after 25-35 years of age. Antibodies against the 3 remaining antigens, including the endotoxin-like antigen, Ag7, were acquired earlier with a plateau of maximum prevalence reached after 5-11 years, i.e. at the time when morbidity due to malaria decreased. Children who had not appeared to be infected with malaria during the preceding transmission season had lower levels of antibodies to soluble antigens than did children who had had a documented attack of clinical malaria or parasitaemia. There was no difference in antibody profiles to soluble antigens between children with sickle cell trait and children with normal haemoglobin.
Adolescent↗
Epidemiology of Haemophilus influenzae type b infections among children in Denmark in 1985 and 1986.
A retrospective epidemiological study of invasive Haemophilus influenzae type b infections among children in Denmark 1985 and 1986 was carried out and 226 cases were identified. Of these 93% occurred in patients younger than five, corresponding to an annual incidence of 40 cases per 100,000 children aged 0-4 years, 68% occurred in patients younger than two years of age, and 6% in patients younger than six months. The annual incidences of meningitis and epiglottis were 27 and 8 cases, respectively, per 100,000 children aged 0-4 years. Of the 156 cases with meningitis four patients died and seven had severe neurological sequelae. Only 67% of the cases of meningitis had been notified.
Adolescent↗
Reported side effects to chloroquine, chloroquine plus proguanil, and mefloquine as chemoprophylaxis against malaria in Danish travelers.
BACKGROUND: The aim of the study was to provide data on the relative frequency of reported symptoms in travelers using chloroquine, chloroquine plus proguanil, and mefloquine. METHOD: The study was an open, nonrandomized study recording self-reported events in travelers recruited consecutively from two travel clinics in Copenhagen, Denmark. The main outcome measures were the relative proportion of travelers reporting particular symptoms in the three prophylaxis groups, compliance, hospitalization and premature termination of the travel. RESULTS: From May 1996 to April 1998 5, 446 travelers were included and 4,158 questionnaires (76.3%) returned. Compliance was significantly better in mefloquine users with 83.3% of short term travelers compared to 76.3% in chloroquine plus proguanil users. Also, 84.8%, 59.3% and 69.5% using chloroquine, chloroquine plus proguanil, and mefloquine respectively reported no symptoms and 0.6%, 1.1% and 2.8% reported "unacceptable" symptoms. Compared to chloroquine, mefloquine users had a significantly higher risk of reporting depression, RR 5.06 (95% CI 2.71 - 9.45), "strange thoughts," RR 6.36 (95% CI 2.52 - 16.05) and altered spatial perception, RR 3.00 (95% CI 1.41 - 6.41). CONCLUSION: Overall mefloquine is tolerated at least as well as chloroquine plus proguanil and shows better compliance, however, symptoms related to the central nervous system are more prevalent in mefloquine users and when symptoms develop, they are perceived as more severe.
Antimalarials↗
Sex-specific patterns of spleen recolonization in semiallogeneic "Sjögren-mice".
"Sjögren-mice" were produced by the transfer of two entire spleen equivalents of cells from parental strain mice to non-irradiated, adult F1 hybrids. The recipients developed an autoimmune exocrinopathy resembling primary Sjögren's syndrome. Since donor and host mice are haploidentical, no new antigens are introduced into the recipients. Donor cells may react against recipient antigens, eliciting a graft versus host (GVH) reaction. The origin of spleen cells was investigated by flow cytometry, using antibodies against murine MHC antigens. The results showed different colonization patterns: spleens of female recipients, grafted with cells from female donors, were almost completely colonized by donor type cells, whereas spleens of male recipients, grafted with either male or female cells, showed partial or complete colonization by donor type cells. The results suggest that the sex of both donor and host influences cellular reactions in lymphohaemopoietic chimeras.
Animals↗