Coccidian parasites of the genus Eimeira cause coccidiosis in farm animals, which develop in both the small and the large intestines. Coccidiosis is a major economic concern in many livestock, especially in young animals, as a result of losses caused by clinical infection (diarrhea) and subclinical (poor weight gain in particular) and the required treatment costs. Herein, we summarize geographical distribution of Eimeria parasites, their life cycle, pathogenesis, clinical signs, economic losses due to coccidiosis, diagnosis, recent information on control and prevention, and anticoccidial drugs for Eimeria infection in goats. With regard to poverty alleviation in most developing agricultural countries, it is important to maintain and develop goat-related industries. Proper management should be used to prevent losses and reduce the productivity from coccidiosis in young animals by: reducing the level of environmental contamination by infectious oocysts; minimizing stress; and avoiding overcrowding.
Summary. Background: The adapter proteins SLP‐76 and LAT have been shown to play critical roles in the activation of PLCγ2 in platelets downstream of GPVI/FcRγ and the C‐type lectin receptor CLEC‐2. SLP‐76 is constitutively associated with the adapter Gads in platelets, which also binds to tyrosine phosphorylated LAT, thereby providing a potential pathway of regulation of SLP‐76. Objective: In the present study, we have compared the role of Gads alongside that of LAT following activation of the major platelet glycoprotein receptors using mice deficient in the two adapter proteins. Results: Gads was found to be required for the efficient onset of aggregation and secretion in response to submaximal stimulation of GPVI and CLEC‐2, but to be dispensable for activation following stronger stimulation of the two receptors. Gads was also dispensable for spreading induced through integrin αIIbβ3 or the GPIb–IX–V complex. Further, Gads plays a negligible role in aggregate formation on collagen at an arteriolar rate of shear. In stark contrast, platelets deficient in the adapter LAT exhibit a marked decrease in aggregation and secretion following activation of GPVI and CLEC‐2, and are unable to form stable aggregates on collagen at arteriolar shear. Conclusions: The results demonstrate that Gads plays a key role in linking the adapter LAT to SLP‐76 in response to weak activation of GPVI and CLEC‐2 whereas LAT is required for full activation over a wider range of agonist concentrations. These results reveal the presence of a Gads‐independent pathway of platelet activation downstream of LAT.
Stimulation of NK cell-mediated cytotoxicity involves the coupling of proximal Src and Syk family protein tyrosine kinases to downstream effectors. However, the mechanisms linking these second messenger pathways are incompletely understood. Here, we describe a key role for the LAT (p36) adaptor protein in human NK cell activation. LAT is tyrosine phosphorylated upon stimulation of NK cells through FcgammaRIII receptors and following direct contact with NK-sensitive target cells. This NK stimulation induces the association of LAT with several phosphotyrosine-containing proteins. In addition to the biochemical evidence showing LAT involvement in NK cell activation, a genetic model shows that LAT is required for FcR-dependent phosphorylation of phospholipase C-gamma. Furthermore, overexpression of LAT in NK cells leads to increased Ab-dependent cell-mediated cytotoxicity and "natural cytotoxicity," thus demonstrating a functional role for LAT in NK cells. These data suggest that LAT is an important adaptor protein for the regulation of human NK cell-mediated cytotoxicity.