Biomedical subjects

B M Sölder

Publications and source records attributed to B M Sölder.

4 recordsLinked to original sources

PubMed1996

The Cayapa Indians of Ecuador: a genetically isolated group with unexpected complement C7 M/N allele frequencies.

The Cayapa Indians live in north-western Ecuador in close proximity to a Black population of African ancestry. C7 M/N allotyping has proved to be a good technique for plasma genetic analysis in several populations. Investigation of 124 Cayapa plasma samples revealed the highest allele frequency of C7*N observed in any population examined so far (0.36 versus 0.225 or lower). The marked difference in frequency compared with several Oriental populations, which are believed to have been derived from the same Asian population as native Amerindians, may reflect the effect of a small founder population followed by a high degree of genetic isolation. The allele frequency of 0.12 for C7*N determined for the neighbouring Black population supports the conclusion that there has been a lack of genetic admixture of Cayapas with other populations, confirming the results of ethnohistorical investigations and other protein polymorphism studies.

Alleles↗

PubMed1995

Complement C7 M/N allotyping in infectious diseases.

The allotypes of the C7 M/N polymorphism are determined by ELISA by comparing the reaction pattern of the allospecific monoclonal antibody WU 4-15 with that of polyclonal anti-C7 IgG. In order to find disease associations of the two alleles C7*M and C7*N we tested 528 hospitalised patients, most of them suffering from infectious diseases. No significant association of either of the two C7 M/N alleles to a particular disease was found, in particular refuting the hypothesis that Lyme borreliosis may be more frequent in homozygous carriers of the hypomorphic allele C7*N.

Alleles↗

PubMed1989

HIV and HIV-infected cells differentially activate the human complement system independent of antibody.

The human retroviruses HTLV-I and HIV-I have previously been shown not to be lysed by human serum. An interaction between HIV and the complement system, however, has not been investigated in any detail. In this report we show that purified HIV as well as HIV-infected cells activate the complement system. In the case of virus-infected cells this activation is mediated by the alternative pathway of complement, whereas the classical pathway seems to be in operation for the triggering of the complement system by purified virus and recombinant envelope glycoprotein (gp 160). We demonstrate that this leads to the deposition of C3b and/or C3bi on the surface of infected cells. But the HIV-infected cells are not lysed by human complement. C3 fragments deposited on the surface of HIV-infected cells are capable of mediating immune adherence to complement receptor-bearing cells, such as human erythrocytes and phagocytes. Whether this might have an influence on infectivity of HIV for certain cells bearing complement receptors has yet to be shown.

Cell Line↗

PubMedDate not supplied

Hepatitis A in Western Austria--the epidemiological situation before the introduction of active immunisation.

Several European countries report a decreasing prevalence of antibodies to hepatitis A virus (anti-HAV). This trend is most pronounced in the youngest age groups. In 1979, however, 58% of young Austrians aged 20 to 30 years were shown to possess anti-HAV. Here we describe the current epidemiological situation in western Austria. Prevalence of anti-HAV has decreased to 7% in those 18 to 30 years old. This percentage rises to 20% (31 to 40 years of age) and 57% (41 to 50 years of age) and is highest in those older than 50 years (87%). Of 180 cases of clinical hepatitis A occurring from 1985 to 1992 45% were imported by travel to HAV-endemic areas. Seventy-one percent of the cases in children (59/83) occurred in foreign workers' families and were also predominantly acquired abroad. A change in prevention policy should be considered in this respect, as vaccination is available now.

Adolescent↗