ABSTRACT
Allelic frequencies for 19 STR loci (F13B, TPOX, D3S1358, FGA, CSF1PO, D5S818, F13A01, D7S820, D8S1179, D10S1237, TH01, VWA, D13S317, FESFPS, Penta E, D16S539, D18S51, D19S253, and D21S11) were obtained from an average of 13,000 unrelated Brazilian adults undergoing parentage testing. D10S1237 is a tetranucleotide repeat locus shown to be useful for forensic and paternity studies. Null allele frequencies and mutation rates were ascertained from this population sample.
Subject(s)
Gene Frequency , Genetics, Population , Mutation , Tandem Repeat Sequences , Brazil , DNA Fingerprinting/methods , HumansABSTRACT
Guinea-pigs were experimentally infected with L. interrogans serovar copenhageni serogroup Icterohaemorrhagiae and their liver and kidney were studied by immunoelectron microscopy using the post embedding indirect immunogold labelling technique. Primary antibody was a purified rabbit anti-serum produced against the same leptospiral strain used in the inoculum. Gold-labelled leptospiral antigen (LAg) was found close to cell membranes of hepatocytes, kidney tubular cells and endothelial cells of the interstitial capillaries of the kidney. Afterwards it was internalized by hepatic and tubular cells, and eventually found in lysosomes. Phagolysosomes of Kupffer cells were also found to contain remnants of degraded leptospires and gold-labelled LAg. Gold-labelled intact leptospires were detected at the enlarged intercellular spaces between hepatocytes at the areas of hepatic cell plate disarray, showing the potential for leptospiral migration during the septicaemic phase of the disease potentially contributing to the pathogenesis of the lesions. The affinity of leptospiral antigenic material for cell membranes suggests an initial interaction with cell surface proteins followed by its internalization and cell damage. The nature of antigenic material detected, however, remains undefined; it may be a toxin, an enzyme or any other factor/s involved in leptospiral virulence.
