Purification and partial characterization of a thermo-stable lipoprotein ("antigen 880") of hydatid cyst fluid (HCF).

A purification procedure for a HCF thermo-stable lipoprotein designated as "Antigen 880" and subsequent characterization are described. The molecular weight and PI of the lipoprotein were shown to be 240,000 daltons and 4.2 respectively. The antigenic activity of "Antigen 880" was not affected by trypsinization, pepsinization and delipidization. This suggested that the antigen activity of the lipoprotein recided in both the protein and lipid moieties. Treatment of the antigen with various concentrations of iodoacetamide and dithiothreital (DTT) and subsequent assay for antigenic activity showed that the two chemicals did not affect antigenic activity. This suggested that the di-suphide bonds were not a pre-requisite to antigenic integrity of the lipoprotein. After heating HCF at temperature between 105-121 degrees C, it was shown that "Antigen 880" was the only HCF antigen which retained activity at these temperatures. Further analysis of the supernate obtained after heating concentrated HCF at a temperature of 110 degrees C for 10 minutes by use of Sephadex G-200 column showed two peaks. Antigenic activity specific for "Antigen 880" was obtained in Peak I, while no antigen activity was found in Peak II. When Peak I was analyzed using step-by-step DEAE 52 ion exchange chromatography, only one peak was eluted with 0.2M phosphate buffer, pH 8.5. This peak had antigenic activity for "Antigen 880". Analysis by disc-gel electrophoresis of the antigenic preparation obtained from the DEAE-cellulose column revealed one protein species. "Antigen 880" was shown to be stable for 10 months after incubation at pH1-11.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of human hydatid disease in surgically-confirmed cases by the use of the indirect haemagglutination test based on a thermo-stable lipoprotein and on unfractionated hydatid cyst fluid.

A total of 204 sera, taken from healthy individuals or from individuals with various parasitic and bacterial infections, were examined by the indirect haemagglutination test. The tests were carried out using either a thermo-stable lipoprotein or unfractionated hydatid cyst fluid, and a titre of 1:64 or above was considered positive. Sixty-two of 70 sera from individuals with surgically-confirmed hydatid disease showed positive reactions with the thermo-stable lipoprotein--a sensitivity of 88%. No false positive reactions were obtained with sera from healthy individuals or from individuals with parasitic or bacterial infections, and no cross-reactions were observed with sera from individuals with multiple myeloma. The lipoprotein antigen thus showed a specificity of 100%. A sensitivity of 88% was obtained with the indirect haemagglutination test using whole hydatid cyst fluid; but positive reactions were obtained from healthy individuals and from individuals with schistosomiasis, leishmaniasis, taeniasis and malaria. No cross-reactions were obtained with sera from patients with gonorrhoea, syphilis or multiple myeloma. Because of the high sensitivity and specificity shown by the thermo-stable lipoprotein ('Antigen 880'), it is considered that this antigen is more useful than unfractionated hydatid cyst fluid in the diagnosis of human hydatidosis in Kenya.

The amino acid and fatty acid composition of the thermostable lipoprotein ("Antigen 880") of hydatid cyst fluid (HCF).

Analysis for the amino acid composition of "Antigen 880" was carried out by use of double dimension paper chromatography and Biotronik 2,000 automatic amino acid analyzer. By the double dimension paper chromatography, leucine, phenylalanine, tyrosine and alanine were identified as amino acid components of the protein moiety of "Antigen 880". In the Biotronik 2,000 automatic amino acid analyzer showed the concentration of the various amino acids to be as follows: isoleucine, leucine, tyrosine, phenylalanine, lysine and histidine were identified as amino acid constituents of "Antigen 880". Quantitative studies in Biotronik 2,000 analyzer showed the concentration of the various amino acids to be as follows: valine -0.85 mumol/ml; leucine - 0.22 mumol/ml. /ml; iso-leucine - 0.18 mumol/ml; tyrosine - 0.04 mumol/ml, and histidine - 0.02 mumol/ml. The fatty acid composition of the lipid moiety of "Antigen 880" was investigated by use of Gas-Liquid chromatography. In this method, C8:0. C10:0, C12:0, C14:0, C16:0 and C18 were identified as the fatty acid constituents of the lipid moiety of "Antigen 880".

Immunological and morphological consequences of vasectomy in the rabbit.

Cell-mediated immunity to spermatozoa was detected in vitro 6--18 months after vasectomy in the rabbit. The autoimmunity was accompanied by aspermatogenic orchitis in the testes and epididymides.

Detection of cell-mediated immunity to spermatozoa in mice and man by the leucocyte adherence-inhibition test.

A modification of the leucocyte adherence-inhibition test was developed to study cell-mediated immunity to spermatozoa. The test is highly reproducible and requires very low numbers of leucocytes. Deposition of spermatozoa in the genital tract of the female mouse by one normal mating is sufficient to sensitize the female to sperm antigens and the degree of sensitization is independent of the number of matings and the strain of male, and is not enhanced by subsequent pregnancy.