A study of foot-and-mouth disease virus strains by complement fixation: I. A model for the fixation of complement by antigen/antibody mixtures

An examination was made of the relations between antigen, antibody and fixation of complement with foot-and-mouth disease virus (FMDV). It was found that complement fixation in this system follows the same principles as models developed in other antigen/antibody systems. The assumption that there is a relation of direct proportionality between the amount of complement fixed and the amount of antiserum reacting with constant antigen was found to be incorrect. An alternative method was proposed for the quantitative differentiation of FMDV strains by comparing the titres of an antiserum when reacting with optimum amounts of homologous or heterologous antigens.     

Synthesis of the carbohydrate moiety from the parasite Echinococcus multilocularis and their antigenicity against human sera

Stereocontrolled syntheses of biotin-labeled oligosaccharide portions with a Galβ1-3GalNAc core of the Em2 glycoprotein antigen obtained from the parasite Echinococcus multilocularis have been accomplished. Trisaccharide Galβ1-3(GlcNAcβ1-6)GalNAcα1-R (G), tetrasaccharide Galβ1-3(Galβ1-4GlcNAcβ1-6)GalNAcα1-R (J) and pentasaccharide Galβ1-3(Galα1-4Galβ1-4GlcNAcβ1-6)GalNAcα1-R (K) (R = biotinylated probe) were synthesized by block synthesis by the use of 5-(methoxycarbonyl)pentyl 2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyl-(1→3)-2-azido-4-O-benzyl-2-deoxy-α-d-galactopyranoside as a common glycosyl acceptor. Moreover, linear trisaccharide Galα1-4Galβ1-3GalNAcα1-R (H) and branched tetrasaccharide Galα1-4Galβ1-3(GlcNAcβ1-6)GalNAcα1-R (I) were synthesized by stepwise condensation. We examined the antigenicity of these five oligosaccharides by an enzyme linked immunosorbent assay (ELISA). Our results demonstrate that biotinylated oligosaccharides H, I and K show good serodiagnostic potential to detect infections caused by the parasite E. multilocularis. Among them the linear sequence Galα1-4Galβ1-3GalNAcα1-R in oligosaccharide (H) appears to show the highest sensitivity (95%). Moreover, our study clarified the dominant carbohydrate epitope of Em2 antigen.     

Kinetics of lymphocyte subpopulations and their functions in cases of amoebic liver abscess

This study shows the relationship between lymphocyte subpopulations and their response to non-specific stimulant phytohaemagglutinin (PHA) and specific stimulant (amoebic antigen) in cases of amoebic liver abscess in relation to the duration of disease, based on the first appearance of symptoms and/or signs. 26 patients with amoebic liver abscess and 20 normal, healthy controls were studied. Five of the patients gave a history of alcohol intake for the last 10 to 15 years. Eight had a solitary abscess and five had multiple abscesses, as seen on liver scan. No change in the B cell count was noticed in any of the patients. Depression of the T cell number and function was noticed from two weeks onwards. A history of alcohol intake made no difference. Cases with multiple liver abscesses were more immunologically depressed than were those with a solitary abscess.     

Residual agglutinins against rickettsial agents in human sera from central and eastern Turkey and their relation to cardiovascular diseases

Many workers have shown that the recrudescence of rickettsial infections may cause cardiovascular diseases of all kinds. As Turkey is a region where rickettsial infections in man are endemic, the relation between such infections and cardiovascular disease has been further studied there. Sera were collected from patients with cardiovascular diseases and also from healthy people and patients with diseases not affecting the heart, who served as a control group. A considerably higher percentage of positive sera was obtained from the patients with cardiovascular diseases, particularly for R. prowazekii, R. conorii and C. burnetii. It was also found that the highest percentage of positive sera was obtained from people in the 20-40 years age-group. Antistreptolysin-O (ASO) determinations were also made and it was found that, on average, agglutinin-negative sera had the higher ASO titres.     

The use of the conglutinating complement fixation test in the diagnosis of human brucellosis.

The conglutinating complement fixation test was compared with the haemolytic complement fixation test for the detection of brucella antibodies in human sera. Conglutinating-complement-fixation antibodies were detectable during the early stages of acute brucellosis and persisted for approximately 1 year after the infection.