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From: TSS (216-119-156-61.ipset36.wt.net)
Subject: Tissue distribution of protease resistant prion protein in variant Creutzfeldt-Jakob disease using a highly sensitive immunoblotting assay
Date: January 29, 2005 at 7:16 pm PST

-------- Original Message --------
Subject: Tissue distribution of protease resistant prion protein in variant Creutzfeldt-Jakob disease using a highly sensitive immunoblotting assay
Date: Sat, 29 Jan 2005 17:03:56 -0600
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy
To: BSE-L@LISTSERV.KALIV.UNI-KARLSRUHE.DE


##################### Bovine Spongiform Encephalopathy #####################


1: Lancet. 2001 Jul 21;358(9277):171-80.

Comment in:

* Lancet. 2001 Jul 21;358(9277):164-5.

* Lancet. 2002 Mar 2;359(9308):801.


Click here to read


Tissue distribution of protease resistant prion protein in variant
Creutzfeldt-Jakob disease using a highly sensitive immunoblotting assay.

Wadsworth JD, Joiner S, Hill AF, Campbell TA, Desbruslais M, Luthert
PJ, Collinge J.

MRC Prion Unit and Department of Neurogenetics, Imperial College
School of Medicine at St Mary's, Norfolk Place, W2 1PG, London, UK.

BACKGROUND: Variant Creutzfeldt-Jakob disease (vCJD) has a
pathogenesis distinct from other forms of human prion disease:
disease-related prion protein (PrP(Sc)) is readily detectable in
lymphoreticular tissues. Quantitation of risk of secondary
transmission, and targeting of risk reduction strategies, is limited
by lack of knowledge about relative prion titres in these and other
peripheral tissues, the unknown prevalence of preclinical vCJD, and
a transmission barrier which limits the sensitivity of bioassay. We
aimed to improve immunoblotting methods for high sensitivity
detection of PrP(Sc) to investigate the distribution of PrP(Sc) in a
range of vCJD tissues. METHODS: We obtained tissues at necropsy from
four patients with neuropathologically confirmed vCJD and from
individuals without neurological disease. Tissues were analysed by
sodium phosphotungstic acid precipitation of PrP(Sc) and western
blotting using high sensitivity enhanced chemiluminescence.
FINDINGS: We could reliably detect PrP(Sc) in the equivalent of 50
nL 10% vCJD brain homogenate, with a maximum limit of detection
equivalent to 5 nl. PrP(Sc) could be detected in tissue homogenates
when present at concentrations 10(4)-10(5) fold lower than those
reported in brain. Tonsil, spleen, and lymph node were uniformly
positive for PrP(Sc) at concentrations in the range of 0.1-15% of
those found in brain: the highest concentrations were consistently
seen in tonsil. PrP(Sc) was readily detected in the retina and
proximal optic nerve of vCJD eye at levels of 2.5 and 25%,
respectively of those found in brain. Other peripheral tissues
studied were negative for PrP(Sc) with the exception of low
concentrations in rectum, adrenal gland, and thymus from a single
patient with vCJD. vCJD appendix and blood (Buffy coat fraction)
were negative for PrP(Sc) at this level of assay sensitivity.
INTERPRETATION: We have developed a highly sensitive immunoblot
method for detection of PrP(Sc) in vCJD tissues that can be used to
provide an upper limit on PrP(Sc) concentrations in peripheral
tissues, including blood, to inform risk assessment models. Rectal
and other gastrointestinal tissues should be further investigated to
assess risk of iatrogenic transmission via biopsy instruments.
Ophthalmic surgical instruments used in procedures involving optic
nerve and the posterior segment of the eye, in particular the
retina, might represent a potential risk for iatrogenic transmission
of vCJD. Tonsil is the tissue of choice for diagnostic biopsy and
for population screening of surgical tissues to assess prevalence of
preclinical vCJD infection within the UK and other populations.

PMID: 11476832 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11476832

Greetings,

> Tissues were analysed by sodium phosphotungstic acid precipitation of
> PrP(Sc) and western blotting using high sensitivity enhanced
> chemiluminescence.


IF this method is better, why are we not using it ???

just curious...

TSS


######### https://listserv.kaliv.uni-karlsruhe.de/warc/bse-l.html ##########





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