3 research outputs found
Impact of Age and Sex of Rocky Mountain Elk (\u3ci\u3eCervus elaphus nelson\u3c/i\u3e) on Follicle Counts From Rectal Mucosal Biopsies for Preclinical Detection of Chronic Wasting Disease
To determine if the number of rectal lymphoid follicles decreases with respect to age and sex relative to diagnosis of chronic wasting disease (CWD), rectal biopsies (n = 1,361) were taken from captive Rocky Mountain elk (Cervus elaphus nelsoni) at 4 ranches in the western United States between 2005 and 2008. Rectal tissues were stained with a monoclonal antibody (F99/97.6.1), which selectively stains the abnormal isoform of the prion protein associated with CWD of elk. The number of lymphoid follicles obtained from typical biopsy tissues decreased with the age of the animal. The acceptable number of lymphoid follicles for detection of CWD was not considered to be a problem in elk up to 8.5 years of age, but in elk over 8.5 years of age, the follicle count was considered to be low. Sex of the animal had no effect on the number of lymphoid follicles observed in each age group. Rectal biopsies were an accurate test to diagnose preclinical stages of CWD in elk but may be best suited to elk that are less then 8.5 years of age
Impact of Age and Sex of Rocky Mountain Elk (\u3ci\u3eCervus elaphus nelson\u3c/i\u3e) on Follicle Counts From Rectal Mucosal Biopsies for Preclinical Detection of Chronic Wasting Disease
To determine if the number of rectal lymphoid follicles decreases with respect to age and sex relative to diagnosis of chronic wasting disease (CWD), rectal biopsies (n = 1,361) were taken from captive Rocky Mountain elk (Cervus elaphus nelsoni) at 4 ranches in the western United States between 2005 and 2008. Rectal tissues were stained with a monoclonal antibody (F99/97.6.1), which selectively stains the abnormal isoform of the prion protein associated with CWD of elk. The number of lymphoid follicles obtained from typical biopsy tissues decreased with the age of the animal. The acceptable number of lymphoid follicles for detection of CWD was not considered to be a problem in elk up to 8.5 years of age, but in elk over 8.5 years of age, the follicle count was considered to be low. Sex of the animal had no effect on the number of lymphoid follicles observed in each age group. Rectal biopsies were an accurate test to diagnose preclinical stages of CWD in elk but may be best suited to elk that are less then 8.5 years of age
Octarepeat region flexibility impacts prion function, endoproteolysis and disease manifestation
Abstract The cellular prion protein (PrPC) comprises a natively unstructured Nâterminal domain, including a metalâbinding octarepeat region (OR) and a linker, followed by a Câterminal domain that misfolds to form PrPSc in CreutzfeldtâJakob disease. PrPC ÎČâendoproteolysis to the C2 fragment allows PrPSc formation, while αâendoproteolysis blocks production. To examine the OR, we used structureâdirected design to make novel alleles, âS1â and âS3â, locking this region in extended or compact conformations, respectively. S1 and S3 PrP resembled WT PrP in supporting peripheral nerve myelination. Prionâinfected S1 and S3 transgenic mice both accumulated similar low levels of PrPSc and infectious prion particles, but differed in their clinical presentation. Unexpectedly, S3 PrP overproduced C2 fragment in the brain by a mechanism distinct from metalâcatalysed hydrolysis reported previously. OR flexibility is concluded to impact diverse biological endpoints; it is a salient variable in infectious disease paradigms and modulates how the levels of PrPSc and infectivity can either uncouple or engage to drive the onset of clinical disease