In the present work we have partially characterized an ecto-phosphatase activity in Crithidia deanei, using viable parasites. This enzyme hydrolyzed p-nitrophenylphosphate at a rate of 3.55 +/- 0.47 nmol Pi/h x 10(8) cells. The dependence on p-NPP concentration shows a normal Michaelis-Menten kinetics for this phosphatase activity and the value of the apparent Km for p-NPP was 5.35 +/- 0.89 mM....

The purine-2'-deoxyribonucleosidase of Crithidia luciliae catalyses an efficient deoxyribosyl transfer between a variety of purine bases, benzimidazole and 5,6-dimethylbenzimidazole. Since the deoxyriboside of a deoxyribosyl acceptor is necessarily also a substrate, the trans-N-deoxyribosylase activity of the enzyme allows a study of its specificity to be extended to a large number of purines a...

INTRODUCTION In recent years, there has been an increased demand for computer-aided diagnosis (CAD) tools to support clinicians in the field of indirect immunofluorescence. To this aim, academic and industrial research is focusing on detecting antinuclear, anti-neutrophil, and anti-double-stranded (anti-dsDNA) antibodies. Within this framework, we present a CAD system for automatic analysis of ...

Parasites infect hosts non-randomly as genotypes of hosts vary in susceptibility to the same genotypes of parasites, but this specificity may be modulated by environmental factors such as nutrition. Nutrition plays an important role for any physiological investment. As immune responses are costly, resource limitation should negatively affect immunity through trade-offs with other physiological ...

INTRODUCTION The objective of the present study was to compare QUANTA Flash dsDNA, a chemiluminescent immunoassay (CIA) on the BIO-FLASH, a rapid-response chemiluminescent analyzer, to three other anti-dsDNA antibody assays and to Crithidia luciliae indirect immunofluorescence test (CLIFT). METHODS In the first part of the study, 161 samples, 61 from patients suffering from systemic lupus ery...

Many parasites, including important species that affect humans and livestock, must survive the harsh environment of insect guts to complete their life-cycle. Hence, understanding how insects protect themselves against such parasites has immediate practical implications. Previously, such protection has been thought to consist mainly of mechanical structures and the action of lectins. However, re...