giardiasis/phosphatase

We found a dipeptidyl aminopeptidase activity in the parasitic protozoan Giardia lamblia with properties similar to the lysosomal cathepsin C of rat-liver lysosomes. Subcellular fractionation of this parasite indicated that the cathepsin C activity is located in organelles not distinguishable from

Giardia muris cysts were incubated briefly in an aqueous induction medium of 0.1 M potassium phosphate with 0.1, 0.2, or 0.3 M sodium bicarbonate. High rates of excystation (91.1-96.7%) were recorded within 5 min after the cysts were placed in trypticase-yeast extract-iron-serum (TYI-S) medium.

Numerous membrane-bounded vacuoles are found adjacent to the plasma membrane of the pathogenic protozoan Giardia lamblia. The function of these vacuoles has been discussed by several authors. Approximately 100-400 nm in diameter with a core of low electron density, they have been suggested to be

We report results on determinations of small intestinal brush-border enzyme activities in 22 children (aged 11 months to 14 years) with giardiasis. In particular, activities of disaccharidases (lactase, sucrase, maltase) and of alkaline phosphatase were investigated. Forty-one percent of the

Alkaline phosphatase (IAP) is a marker of intestinal microvillus membrane. Changes in IAP activity have been studied as a function of Giardia lamblia (G. lamblia) infection using rat as the experimental model. At day 11 and 15 post-infection, enzyme activity was reduced (p<0.01) compared to

Ecto-phosphatase activities of Giardia lamblia were characterized in intact cells, which are able to hydrolyze the artificial substrate p-nitrophenylphosphate (p-NPP) to p-nitrophenol (p-NP) at a rate of 8.4+/-0.8 nmol p-NP/h/10(7) cells. The ecto-phosphatase activities were inhibited at high pH as

Giardia intestinalis is a protozoan parasite that colonizes the upper part of the small intestine of its mammalian hosts. The trophozoite, which is the replicative stage, has a complex cytoskeleton that allows it to move and adhere to intestinal cells. It has been proposed that protein phosphatase

The ability of Giardia lamblia to undergo two distinct differentiations in response to physiologic stimuli is central to its pathogenesis. The giardial cytoskeleton changes drastically during encystation and excystation. However, the signal transduction pathways mediating these transformations are

It is well established that Giardia infection causes malabsorption. However, the precise mechanism of such a malabsorption is not known. To investigate this, transport studies, using the tissue accumulation technique, were carried out in mice infected with G. lamblia obtained from human stools.

We quantified mRNA abundance from 10 stages in the Giardia lamblia life cycle in vitro using Serial Analysis of Gene Expression (SAGE). 163 abundant transcripts were expressed constitutively. 71 transcripts were upregulated specifically during excystation and 42 during encystation. Nonetheless, the

NMRI mice immunosuppressed with dexamethasone followed by challenge intraesophageally with axenic Giardia lamblia (Portland I) trophozoites had severe infection in terms of the trophozoite counts in the jejunum. Although the immunosuppressive treatment with cortisone itself resulted in a deleterious

The present study developed and standardized an enzime-linked immunosorbent assay (ELISA) to detect Giardia antigen in feces using rabbit polyclonal antibodies. Giardia cysts were purified from human fecal samples by sucrose and percoll gradients. Gerbils (Meriones unguiculatus) were infected to

Giardia lamblia, which belongs to the earliest identified lineage to diverge from the eukaryotic line of descent, is one of many protists reported to lack a Golgi apparatus. Our recent finding of a developmentally regulated secretory pathway in G. lamblia makes it an ideal organism with which to