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SRM's, are they enough?

Mike

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Joined
Feb 10, 2005
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Looks as though the people who have defended the practice of removing SRM's as the only way to insure safety might need to rethink:

PrPSc Found in Muscle Tissue


American Journal of Pathology. 2006;168:927-935.)
© 2006 American Society for Investigative Pathology
Detection and Localization of PrPSc in the Skeletal Muscle of Patients with Variant, Iatrogenic, and Sporadic Forms of Creutzfeldt-Jakob Disease
Alexander H. Peden, Diane L. Ritchie, Mark W. Head and James W. Ironside

From the National Creutzfeldt-Jakob Disease Surveillance Unit and Division of Pathology, School of Molecular and Clinical Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom

Variant Creutzfeldt-Jakob disease (vCJD) differs from other human prion diseases in that the pathogenic prion protein PrPSc can be detected to a greater extent at extraneuronal sites throughout the body, principally within lymphoid tissues. However, a recent study using a high-sensitivity Western blotting technique revealed low levels of PrPSc in skeletal muscle from a quarter of Swiss patients with sporadic CJD (sCJD). This posed the question of whether PrPSc in muscle could also be detected in vCJD, sCJD, and iatrogenic (iCJD) patients from other populations. Therefore, we have used the same high-sensitivity Western blotting technique, in combination with paraffin-embedded tissue blotting, to screen for PrPSc in muscle tissue specimens taken at autopsy from 49 CJD patients in the United Kingdom. These techniques identified muscle PrPSc in 8 of 17 vCJD, 7 of 26 sCJD, and 2 of 5 iCJD patients. Paraffin-embedded tissue blotting analysis showed PrPSc in skeletal muscle in localized anatomical structures that had the morphological and immunohistochemical characteristics of nerve fibers. The detection of PrPSc in muscle tissue from all forms of CJD indicates the possible presence of infectivity in these tissues, suggesting important implications for assessing the potential risk of iatrogenic spread via contaminated surgical instruments.



http://ajp.amjpathol.org/cgi/content/abstract/168/3/927
 
However, a recent study using a high-sensitivity Western blotting technique revealed low levels of PrPSc in skeletal muscle.Not a big deal if you don't like beef.If you do like beef then testing will be the norn at some point in time.
 
Now your jumping species again Mike.

However that aside, the fact that in an animal (human) that died of a TSE there are minute amounts of misfolded prions, how does that prove there are any misfolded prions in young cattle that exhibit no symptoms?

If the disease progresses it is logical that misfolded prions will be found everywhere in the body, all systems are connected in some fashion.

The question is if the misfolded prions occur first in SRM and they are barely detectable there in the handful of under 30 month old cases found worldwide, it is a real risk to eat the meat?

I think youd have a better chance of winning the lottery and getting hit by lightning at the same time on your birthday in a trek across the Sahara desert.
 
Jason said:
Now your jumping species again Mike.

However that aside, the fact that in an animal (human) that died of a TSE there are minute amounts of misfolded prions, how does that prove there are any misfolded prions in young cattle that exhibit no symptoms?

If the disease progresses it is logical that misfolded prions will be found everywhere in the body, all systems are connected in some fashion.

The question is if the misfolded prions occur first in SRM and they are barely detectable there in the handful of under 30 month old cases found worldwide, it is a real risk to eat the meat?

I think youd have a better chance of winning the lottery and getting hit by lightning at the same time on your birthday in a trek across the Sahara desert.

That's not the point at all Jason. We have been led to believe that there is no chance of infectivity with the removal of SRM's. Woe be the day that we have a couple of people who die of vCJD in North America.

Prusiner did research years ago that showed misfolded prions in muscle tissue. This research reiterates it.

Sure the odds are low. But the press will have a field day. Again.
 
I don't think the press will do anything about it Mike. The BSE thing here is a non issue from what I saw when the last one was announced.

People have learned enough that it isn't an epidemic waiting to happen. Avian flu is more of a concern because it can be spread between species relatively easily and just has to be breathed in, yet there isn't much concern for that because it hasn't got here yet.

There is danger in everything we do. If we worry about the tiny stuff like catching BSE when there are safegards in place our quality of life will suffer. People have enough to worry about without all the rare diseases out there besides.

We have picked up a handful of beef customers wanting to know where their food comes from. Most of them still need to see a price advantage for them to do it though.
 
I don't think the press will do anything about it Mike. The BSE thing here is a non issue from what I saw when the last one was announced.

Tell that to the Japs. Canada has lost several BILLION and the U.S. has lost several BILLION. And you say it is a non-issue?

Plus, it's just one more feather in the veggie's hat.
 
Proper SRM removal would have kept the Japanese market open to the States. It has from Canada.

North American consumers have proven it is a non issue with increased beef consumption. Regular factors like cost of living and price of beef will drive their choices from here on out.

So pretty much yeah it is a non issue. I hope researchers keep doing tests and we someday know all there is to know, but look at cancer, aids, even TB. Research hasn't eliminated those and most people don't live in fear of them. Take basic precautions and try to live a healthy life.

It would ruin a lot more peoples way of life trying to test everything for everything. If it became mandatory to test all cattle slaughtered for BSE what about Robert Mac? What about my deal where I sell a few privately? If costs increase again less beef sells. The logistics of testing everything is mind boggling. The bit spewed about it only costs $20 is just for the test. Not reading it, sending it collecting it holding the beef until it is done etc etc etc.
 
Jason
"I don't think the press will do anything about it Mike. The BSE thing here is a non issue from what I saw when the last one was announced.


I disagree--We are a reactionary not proactive country...Nothing is taken serious until something major happens- in our backyard...9-11 is a good example- Al Quaeda was around for years- and had attacked us several times overseas- and was known by military and intelligence agencies to be a major threat....Also the BSE rules...USDA spent years positively proactively drawing up a good scientific BSE response- which was all thrown out the door in a few months of reacting to Big Bucks pressure.....And when/if people begin dying they will overreact again- the other way....

We are also a citizenry that puts great faith in our government to protect us- be it food, drugs, scams etc..Many the time I've heard "I thought it must have been on the up and up because I saw it advertised in a magazine, or newspaper or on TV- doesn't the government check all these things out first?" US consumers are lulled into a false security...

No- If USDA's science is flawed and people in North America (especially US) start dying from vCJD, the proverbial sh!t will hit the fan...And the press will massacre whichever administration is in office...Bush and Johanns probably won't be around - Cheney might be dead by then- many of the legislators and administrators will be gone ( I'm sure they are counting on this)--but it will devastate the cattle industry....
 
Jason, why not try to eradicate BSE? You are comfortable with lumping BSE with cancer, AIDS, TB? Good grief! How can a person who makes their living from cattle take such a stand?

I continually preach to look at examples to formulate opinions and decisons - we've got a great example with the billions we've lost - and are continueing to lose on the Japanese market, and you're balking at a $20 test? Grab your calculator compare the cost of testing 90 million cattle with a $20 test with the losses of ONE YEAR from losing the Japanese market! And nobody has actually gotten sick yet! What is going to happen if people do start getting sick - wouldn't it be nice to say to consumers, "They contracted the disease when we didn't even know the extent of the disease in our herd. Realizing the potential problems, we got busy with testing and evidence now shows our herd is BSE free."

An ounce of prevention is worth a pound of cure. Maybe with the good cattle prices we have, now would be the best time to test everything that moos so we can get on top of BSE and beat it. I think it is wiser to beat it than deal with it. We're not talking about foot-rot or pinkeye here.
 
Sandhusker...An ounce of prevention is worth a pound of cure. Maybe with the good cattle prices we have, now would be the best time to test everything that moos so we can get on top of BSE and beat it. I think it is wiser to beat it than deal with it. We're not talking about foot-rot or pinkeye here.

Don't the Japanese test 100% of their own cattle for BSE? If that is so, they were not asking us to do something that they are not doing.
 
How can you make the leap that I don't want BSE eradicated?

Testing at current levels (in Canada at least) is doing the job. SRM removal and the feed ban are secure. IF and that is a big IF, it is proven there is still an amplification of BSE cases then further measures will need to be taken. Proof is that countries that impose a feed ban drastically reduce their cases of BSE. Canada had the feed ban in place well before any cows appeared. This would show Canada is years ahead of countries that waited until they found their number 1 case before banning ruminant to ruminant feeds.

I say let the scientists that are researching BSE keep on keeping on. It isn't the end of the world if they never find the ultimate cause. It would be nice though.

Those that are selling tests have an agenda and they can keep promoting 100% testing, but it is fear mongering to say WHEN people start dying from a TSE. To use the same line to keep borders shut to countries years into feed bans with minimal cases is just protectionism as well.

If people were going to die from BSE related illnesses, it would be happening in Britian. It isn't.
 
Jason, "SRM removal and the feed ban are secure"

If your feed ban is secure, how do you explain your latest BSE case? The second to the last one was "left-over feed". This one was born two years after the ban. Do you folks buy a couple years worth of supply at a time?
 
Sandhusker said:
Jason, "SRM removal and the feed ban are secure"

If your feed ban is secure, how do you explain your latest BSE case? The second to the last one was "left-over feed". This one was born two years after the ban. Do you folks buy a couple years worth of supply at a time?

Sandhusker, The UK had 40,000 positives after the feed ban. It was all leftover feed too. Go figure.
 
Sandhusker said:
Jason, "SRM removal and the feed ban are secure"

If your feed ban is secure, how do you explain your latest BSE case? The second to the last one was "left-over feed". This one was born two years after the ban. Do you folks buy a couple years worth of supply at a time?

Do you go in and sweep out every crevise and corner of your feed bins? (oh that's right you don't have feed or bins.) :roll: :roll:

I didn't do ours and I doubt many producers on either side of the line did.
 
Bill said:
Sandhusker said:
Jason, "SRM removal and the feed ban are secure"

If your feed ban is secure, how do you explain your latest BSE case? The second to the last one was "left-over feed". This one was born two years after the ban. Do you folks buy a couple years worth of supply at a time?

Do you go in and sweep out every crevise and corner of your feed bins? (oh that's right you don't have feed or bins.) :roll: :roll:

I didn't do ours and I doubt many producers on either side of the line did.

Got the firetruck from down at the volunteer fire dept and washed mine out last year. Small feed bins that hold 10 tons each.

I was trying to get out old molasses residue. Little did I know.
 
Bill said:
Sandhusker said:
Jason, "SRM removal and the feed ban are secure"

If your feed ban is secure, how do you explain your latest BSE case? The second to the last one was "left-over feed". This one was born two years after the ban. Do you folks buy a couple years worth of supply at a time?

Do you go in and sweep out every crevise and corner of your feed bins? (oh that's right you don't have feed or bins.) :roll: :roll:

I didn't do ours and I doubt many producers on either side of the line did.

I guess your feed ban isn't secure, then.
 
Jason wrote:

If people were going to die from BSE related illnesses, it would be happening in Britian. It isn't.

On this you are wrong.

Anne Richardson Age: 41 Died 1996
Alison Margaret Williams Age: 30 Died 1996
Michell Bowen Age: 29 Died 1995
Peter Hall Age: 20 Died 1996
Jean Wake Age: 38 Died 1995
Joan Davidson Age: 51 Died 1989
Elizabeth Bottle Age: 59 Died 1996
Elizabeth Davidson Age: 59 Died 1996
Keith Humphrey Age: 41 Died 1996
Janice Stuart Age: 34 Died 1996
Iris Harris Age: 66 Died 1994
Victoria Lowther Age: 19 Died 1996
Stephen Churchill Age: 19 Died 1995
Mike Bowden Age: 57 Died 1996
Ivy Tattersley Age: 72 Died 1992
Len Franklin Age: 53 Died 1996
Helen Lowe Age: 58 Died 1994
Ralph Boutflower Age: 53 Died 1989
Kevin Stock Age: 63 Died 1993
Barbara Lydiat Age: 37 Died 1993
Brian Davies Age: 41 Died 1996
Dennis Hogan Age: 58 Died 1995
Maurice Callaghan Age: 30 Died 1995
Doreen Gay Age: 61 Died 1993
Fonnie Andrews Age: 44 Died 1994

The list is much much longer and will continue to have names added to it as the years go by.

A number of these folks died within months of being diagnosed with nvCJD. The remarkable thing to note is the age of the victims. Some, in the teens or early twenties, succumbed to the disease after only a few months. This is the nature of the variant beast. It doesn't act like conventional CJD. It is rapid and it is lethal and it is about time we sat up and took notice.

I have the records of these folks and their pathology to an extent that gives and insight as to their symptoms, the onset of visible and noticeable symptoms and so on.

It is truly wrong to suggest that nobody has died of nvCJD in the UK. Many have and they have been documented not only by their doctors, but by the coroners at the time of the medical inquests. A number of these people died after receiving blood and others are noted to have died after receiving contaminated meat. The British Government also indicated, after years of silence, that it would be wise to consider the fact the there is a serious risk of contracting nv>vCJD from consumming contaminated meat and meat products. They (British Government) estimated that a great number of people in the British Isles were already harboring PrPsc due to consumming contaminated meat and that the length of the incubation period would become one of Britains most horrible medical nightmares in the coming decades.

But to make idle statements that nobody is dying in Britain due to BSE related causes is not only worng, it is, in my opinion, damned ignorant! The truth is out there and all you have to do is search for it. It is easy to find so please, with respect, do some due diligence before you make statements that are simply not true.

Jason also wrote:
I don't think the press will do anything about it Mike. The BSE thing here is a non issue from what I saw when the last one was announced.

The fact that Canada lost over 7 Billion Dollars is a far cry from being a "Non-issue." Further to this, tell that to the folks that lost everything that took generations to build!!
 
##################### Bovine Spongiform Encephalopathy #####################


Subject: Creutzfeldt Jakob disease statistics Monday 6 March 2006 Reference number: 2006/0088
Date: March 6, 2006 at 3:22 pm PST


Monthly Creutzfeldt Jakob disease statistics
Published:
Monday 6 March 2006
Reference number:
2006/0088


The Department of Health is today issuing the latest information about the numbers of known cases of Creutzfeldt Jakob disease. This includes cases of variant Creutzfeldt Jakob disease (vCJD) - the form of the disease thought to be linked to BSE. The position is as follows:

Definite and probable CJD cases in the UK:

As at 3 March 2006

Summary of vCJD cases

Deaths

Deaths from definite vCJD (confirmed): 110

Deaths from probable vCJD (without neuropathological confirmation): 44

Deaths from probable vCJD (neuropathological confirmation pending): 0

Number of deaths from definite or probable vCJD (as above): 154

Alive

Number of probable vCJD cases still alive: 6

Total number of definite or probable vCJD (dead and alive): 160

The next table will be published on Monday 3rd April 2006

Referrals: a simple count of all the cases which have been referred to the National CJD Surveillance Unit for further investigation in the year in question. CJD may be no more than suspected; about half the cases referred in the past have turned out not to be CJD. Cases are notified to the Unit from a variety of sources including neurologists, neuropathologists, neurophysiologists, general physicians, psychiatrists, electroencephalogram (EEG) departments etc. As a safety net, death certificates coded under the specific rubrics 046.1 and 331.9 in the 9th ICD Revisions are obtained from the Office for National Statistics in England and Wales, the General Register Office for Scotland and the General Register Office for Northern Ireland.

Deaths: All columns show the number of deaths that have occurred in definite and probable cases of all types of CJD and GSS in the year shown. The figures include both cases referred to the Unit for investigation while the patient was still alive and those where CJD was only discovered post mortem (including a few cases picked up by the Unit from death certificates). There is therefore no read across from these columns to the referrals column. The figures will be subject to retrospective adjustment as diagnoses are confirmed.

Definite cases: this refers to the diagnostic status of cases. In definite cases the diagnosis will have been pathologically confirmed, in most cases by post mortem examination of brain tissue (rarely it may be possible to establish a definite diagnosis by brain biopsy while the patient is still alive).

Probable vCJD cases: are those who fulfil the 'probable' criteria set out in the Annex and are either still alive, or have died and await post mortem pathological confirmation. Those still alive will always be shown within the current year's figures.

Sporadic: Classic CJD cases with typical EEG and brain pathology. Sporadic cases appear to occur spontaneously with no identifiable cause and account for 85% of all cases.

Probable sporadic: Cases with a history of rapidly progressive dementia, typical EEG and at least two of the following clinical features; myoclonus, visual or cerebellar signs, pyramidal/extrapyramidalsigns or akinetic mutism.

Iatrogenic: where infection with classic CJD has occurred accidentally as the result of a medical procedure. All UK cases have resulted from treatment with human derived pituitary growth hormones or from grafts using dura mater (a membrane lining the skull).

Familial: cases occurring in families associated with mutations in the PrP gene (10 - 15% of cases).

GSS: Gerstmann-Straussler-Scheinker syndrome - an exceedingly rare inherited autosomal dominant disease, typified by chronic progressive ataxia and terminal dementia. The clinical duration is from 2 to 10 years, much longer than for CJD.

vCJD: Variant CJD, the hitherto unrecognised variant of CJD discovered by the National CJD Surveillance Unit and reported in The Lancet on 6 April 1996. This is characterised clinically by a progressive neuropsychiatric disorder leading to ataxia, dementia and myoclonus (or chorea) without the typical EEG appearance of CJD. Neuropathology shows marked spongiform change and extensive florid plaques throughout the brain.

Definite vCJD cases still alive: These will be cases where the diagnosis has been pathologically confirmed (by brain biopsy).

Related links
Download CJD statistics March 2006 (PDF, 12K)
Notes to editor
ANNEX

DIAGNOSTIC CRITERIA FOR VARIANT CJD

I A) PROGRESSIVE NEUROPSYCHIATRIC DISORDER

B) DURATION OF ILLNESS > 6 MONTHS

C) ROUTINE INVESTIGATIONS DO NOT SUGGEST AN ALTERNATIVE DIAGNOSIS

D) NO HISTORY OF POTENTIAL IATROGENIC EXPOSURE

II A) EARLY PSYCHIATRIC SYMPTOMS *

B) PERSISTENT PAINFUL SENSORY SYMPTOMS **

C) ATAXIA

D) MYOCLONUS OR CHOREA OR DYSTONIA

E) DEMENTIA

III A) EEG DOES NOT SHOW THE TYPICAL APPEARANCE OF SPORADIC CJD *** (OR NO EEG PERFORMED)

B) BILATERAL PULVINAR HIGH SIGNAL ON MRI SCAN

IV A) POSITIVE TONSIL BIOPSY

DEFINITE: IA (PROGRESSIVE NEUROPSYCHIATRIC DISORDER) and NEUROPATHOLOGICAL CONFIRMATION OF vCJD ****

PROBABLE: I and 4/5 OF II and III A and III B or I and IV A

* depression, anxiety, apathy, withdrawal, delusions.

** this includes both frank pain and/ or unpleasant dysaesthesia

*** generalised triphasic periodic complexes at approximately one per second

****spongiform change and extensive PrP deposition with florid plaques, throughout the cerebrum and cerebellum.


Reference number:
2006/0088


http://www.dh.gov.uk/PublicationsAndStatistics/PressReleases/PressReleasesNotices/fs/en?CONTENT_ID=4131172&chk=EejSdT


ALL CJD * As at 3rd March 2006 (see increase in sCJD)



http://www.dh.gov.uk/assetRoot/04/13/11/73/04131173.pdf




USA


notice steady increase, but also notice in 2005, # 7 the 38 pendings cases through Oct. and #8 includes 53 type pending, 1 type unknown.

if you look at 2003 there were 3 type unknown.

wonder if they were the same or different than the unknown in 2005?

considering the soup that has been brewing over here in the USA for years via the rendering of BSE and atypical TSE in cattle, CWD, Scrapie, a few TME cases (not too much due to scent gland, but there were a few rendered, but all this, and you have one hell of a recipe for a new strains of TSE in humans. then who knows what 'friendly fire' cases would look like from this soup via secondary transmission via medical/surgical/dental arena. ...TSS


National Prion Disease Pathology Surveillance Center case exams...



http://www.cjdsurveillance.com/resources-casereport.html





HUMAN and ANIMAL TSE Classifications i.e. mad cow
disease and the UKBSEnvCJD only theory

TSEs have been rampant in the USA for decades in many
species, and they all have been rendered and fed back
to animals for human/animal consumption. I propose that
the current diagnostic criteria for human TSEs only
enhances and helps the spreading of human TSE from the
continued belief of the UKBSEnvCJD only theory in 2005.
With all the science to date refuting it, to continue
to validate this myth, will only spread this TSE agent
through a multitude of potential routes and sources
i.e. consumption, surgical, blood, medical, cosmetics
etc. I propose as with Aguzzi, Asante, Collinge,
Caughey, Deslys, Dormont, Gibbs, Ironside, Manuelidis,
Marsh, et al and many more, that the world of TSE
Tranmissible Spongiform Encephalopathy is far from an
exact science, but there is enough proven science to
date that this myth should be put to rest once and for
all, and that we move forward with a new classification
for human and animal TSE that would properly identify
the infected species, the source species, and then the
route. This would further have to be broken down to
strain of species and then the route of transmission
would further have to be broken down. Accumulation and
Transmission are key to the threshold from subclinical
to clinical disease, and of that, I even believe that
physical and or blunt trauma may play a role of onset
of clinical symptoms in some cases, but key to all
this, is to stop the amplification and transmission of
this agent, the spreading of, no matter what strain.
BUT, to continue with this myth that the U.K. strain of
BSE one strain in cows, and the nv/v CJD, one strain in
humans, and that all the rest of human TSE is one
single strain i.e. sporadic CJD (when to date there are
6 different phenotypes of sCJD), and that no other
animal TSE transmits to humans, to continue with this
masquerade will only continue to spread, expose, and
kill, who knows how many more in the years and decades
to come. ONE was enough for me, My Mom, hvCJD, DOD
12/14/97 confirmed, which is nothing more than another
mans name added to CJD, like CJD itself, Jakob and
Creutzfeldt, or Gerstmann-Straussler-Scheinker
syndrome, just another CJD or human TSE, named after
another human. WE are only kidding ourselves with the
current diagnostic criteria for human and animal TSE,
especially differentiating between the nvCJD vs the
sporadic CJD strains and then the GSS strains and also
the FFI fatal familial insomnia strains or the ones
that mimics one or the other of those TSE? Tissue
infectivity and strain typing of the many variants of
the human and animal TSEs are paramount in all variants
of all TSE. There must be a proper classification that
will differentiate between all these human TSE in order
to do this. With the CDI and other more sensitive
testing coming about, I only hope that my proposal will
some day be taken seriously.


My name is Terry S. Singeltary Sr. and I am no
scientist, no doctor and have no PhDs, but have been
independently researching human and animal TSEs since
the death of my Mother to the Heidenhain Variant of
Creutzfeldt Jakob Disease on December 14, 1997
'confirmed'. ...TSS




Terry S. Singeltary Sr.
P.O. Box 42
Bacliff, Texas USA 77518



SOURCES


Full Text
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
Singeltary, Sr et al.
JAMA.2001; 285: 733-734




http://jama.ama-assn.org/cgi/content/full/285/6/733?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=dignosing+and+reporting+creutzfeldt+jakob+disease&searchid=1048865596978_1528&stored_search=&FIRSTINDEX=0&journalcode=jama




Coexistence of multiple PrPSc types in individuals with

Creutzfeldt-Jakob disease


Magdalini Polymenidou, Katharina Stoeck, Markus
Glatzel, Martin Vey, Anne Bellon, and Adriano Aguzzi


Summary


Background The molecular typing of sporadic
Creutzfeldt-Jakob disease (CJD) is based on the size
and glycoform

ratio of protease-resistant prion protein (PrPSc), and
on PRNP haplotype. On digestion with proteinase K, type
1 and

type 2 PrPSc display unglycosylated core fragments of
21 kDa and 19 kDa, resulting from cleavage around amino

acids 82 and 97, respectively.

Methods We generated anti-PrP monoclonal antibodies to
epitopes immediately preceding the differential proteinase

K cleavage sites. These antibodies, which were
designated POM2 and POM12, recognise type 1, but not
type 2, PrPSc.

Findings We studied 114 brain samples from 70 patients
with sporadic CJD and three patients with variant CJD.

Every patient classified as CJD type 2, and all variant
CJD patients, showed POM2/POM12 reactivity in the

cerebellum and other PrPSc-rich brain areas, with a
typical PrPSc type 1 migration pattern.

Interpretation The regular coexistence of multiple
PrPSc types in patients with CJD casts doubts on the
validity of

electrophoretic PrPSc mobilities as surrogates for
prion strains, and questions the rational basis of
current CJD

classifications.


snip...


The above results set the existing CJD classifications

into debate and introduce interesting questions about

human CJD types. For example, do human prion types

exist in a dynamic equilibrium in the brains of affected

individuals? Do they coexist in most or even all CJD

cases? Is the biochemically identified PrPSc type simply

the dominant type, and not the only PrPSc species?


Published online October 31, 2005




http://neurology.thelancet.com





Detection of Type 1 Prion Protein in Variant

Creutzfeldt-Jakob Disease

Helen M. Yull,* Diane L. Ritchie,*

Jan P.M. Langeveld,? Fred G. van Zijderveld,?

Moira E. Bruce,? James W. Ironside,* and

Mark W. Head*

From the National CJD Surveillance Unit,* School of
Molecular

and Clinical Medicine, University of Edinburgh, Edinburgh,

United Kingdom; Central Institute for Animal Disease
Control

(CIDC)-Lelystad, ? Lelystad, The Netherlands; Institute
for Animal

Health, Neuropathogenesis Unit, ? Edinburgh, United Kingdom

Molecular typing of the abnormal form of the prion

protein (PrPSc) has come to be regarded as a powerful

tool in the investigation of the prion diseases. All
evidence

thus far presented indicates a single PrPSc molecular

type in variant Creutzfeldt-Jakob disease (termed

type 2B), presumably resulting from infection with a

single strain of the agent (bovine spongiform
encephalopathy).

Here we show for the first time that the PrPSc

that accumulates in the brain in variant Creutzfeldt-

Jakob disease also contains a minority type 1 component.

This minority type 1 PrPSc was found in all 21

cases of variant Creutzfeldt-Jakob disease tested,
irrespective

of brain region examined, and was also

present in the variant Creutzfeldt-Jakob disease tonsil.

The quantitative balance between PrPSc types was maintained

when variant Creutzfeldt-Jakob disease was

transmitted to wild-type mice and was also found in

bovine spongiform encephalopathy cattle brain, indicating

that the agent rather than the host specifies their

relative representation. These results indicate that PrPSc

molecular typing is based on quantitative rather than

qualitative phenomena and point to a complex relationship

between prion protein biochemistry, disease phenotype

and agent strain. (Am J Pathol 2006, 168:151-157;

DOI: 10.2353/ajpath.2006.050766)


snip...


Discussion

In the apparent absence of a foreign nucleic acid genome

associated with the agents responsible for transmissible

spongiform encephalopathies or prion diseases,

efforts to provide a molecular definition of agent strain

have focused on biochemical differences in the abnormal,

disease-associated form of the prion protein, termed

PrPSc. Differences in PrPSc conformation and glycosylation

have been proposed to underlie disease phenotype

and form the biochemical basis of agent strain. This

proposal has found support in the observation that the

major phenotypic subtypes of sCJD appear to correlate

with the presence of either type 1 or type 2 PrPSc in

combination with the presence of either methionine or

valine at codon 129 of the prion protein gene.2 Similarly,

the PrPSc type associated with vCJD correlates with the

presence of type 2 PrPSc and is distinct from that found in

sCJD because of a characteristically high occupancy of

both N-linked glycosylation sites (type 2B).6,11 The

means by which such conformational difference is detected

is somewhat indirect; relying on the action of proteases,

primarily proteinase K, to degrade the normal

Figure 6. Type 1 PrPSc is a stable minority component
of PrPSc from the vCJD

brain. Western blot analysis of PrP in a sample of
cerebral cortex from a
case

of vCJD during digestion with proteinase K is shown.
Time points assayed

are indicated in minutes (T0, 5, 10, 30, 60, 120, 180).
Duplicate blots were

probed with 3F4, which detects both type 1 and type 2
PrPSc, and with 12B2,

which detects type 1. The insert shows a shorter
exposure of the same time

course study from a separate experiment also probed
with 3F4. Both blots

included samples of cerebral cortex from a case of
sporadic CJD MM1 (Type

1) and molecular weight markers (Markers) indicate
weights in kd.

Figure 7. A minority type 1-like PrPSc is found in vCJD
tonsil, vCJD
transmitted

to mice and in BSE. Western blot analysis of PrPSc in a
concentrated

sample of tonsil from a case of vCJD (Tonsil), in a
concentrated brain
sample

of a wild-type mouse (C57BL) infected with vCJD and in
a sample of cattle

BSE brain (BSE) is shown. Tissue extracts were digested
with proteinase K.

Duplicate blots were probed with either 3F4 or 6H4,
both of which detect

type 1 and type 2 PrPSc, and with 12B2, which detects
type 1. The blots

included samples of cerebral cortex from a case of
sporadic CJD MM1 (Type

1) and molecular weight markers (Markers) indicate
weights in kd.

Type 1 PrPSc in Variant Creutzfeldt-Jakob Disease 155

AJP January 2006, Vol. 168, No. 1

cellular form of PrP and produce a protease-resistant

core fragment of PrPSc that differs in the extent of its

N-terminal truncation according to the original

conformation.

A complication has recently arisen with the finding that

both type 1 and type 2 can co-exist in the brains of

patients with sCJD.2,5-8 More recently this same phenomenon

has been demonstrated in patients with iatrogenically

acquired and familial forms of human prion disease.

9,10 The existence of this phenomenon is now

beyond doubt but its prevalence and its biological
significance

remain a matter of debate.

Conventional Western blot analysis using antibodies

that detect type 1 and type 2 PrPSc has severe quantitative

limitations for the co-detection of type 1 and type 2

PrPSc in individual samples, suggesting that the prevalence

of co-occurrence of the two types might be underestimated.

We have sought to circumvent this problem by

using an antibody that is type 1-specific and applied this

to the sole remaining human prion disease where the

phenomenon of mixed PrPSc types has not yet been

shown, namely vCJD.

These results show that even in vCJD where susceptible

individuals have been infected supposedly by a

single strain of agent, both PrPSc types co-exist: a
situation

reminiscent of that seen when similarly discriminant

antibodies were used to analyze experimental BSE in

sheep.14,17 In sporadic and familial CJD, individual

brains can show a wide range of relative amounts of the

two types in samples from different regions, but where

brains have been thoroughly investigated a predominant

type is usually evident.2,6,10 This differs from this
report

on vCJD, where type 1 is present in all samples
investigated

but always as a minor component that never

reaches a level at which it is detectable without a type

1-specific antibody. It would appear that the relative
balance

between type 1 and type 2 is controlled within

certain limits in the vCJD brain. A minority type-1-like

band is also detected by 12B2 in vCJD tonsil, in BSE

brain and in the brains of mice experimentally infected

with vCJD, suggesting that this balance of types is agent,

rather than host or tissue, specific. Interestingly the
"glycoform

signature" of the type 2 PrPSc found in vCJD (type

2B) is also seen in the type 1 PrPSc components, suggesting

that it could legitimately be termed type 1B.

PrPSc isotype analysis has proven to be extremely

useful in the differential diagnosis of CJD and is
likely to

continue to have a major role in the investigation of human

prion diseases. However, it is clear, on the basis of

these findings, that molecular typing has quantitative
limitations

and that any mechanistic explanation of prion

replication and the molecular basis of agent strain
variation

must accommodate the co-existence of multiple

prion protein conformers. Whether or not the different

conformers we describe here correlate in a simple and

direct way with agent strain remains to be determined. In

principle two interpretations present themselves: either

the two conformers can be produced by a single strain of

agent or vCJD (and, therefore, presumably BSE) results

from a mixture of strains, one of which generally
predominates.

Evidence for the isolation in mice of more than one

strain from individual isolates of BSE has been presented

previously.18,19

One practical consequence of our findings is that the

correct interpretation of transmission studies will depend

on a full examination of the balance of molecular types

present in the inoculum used to transmit disease, in
addition

to a thorough analysis of the molecular types that

arise in the recipients. Another consequence relates to

the diagnostic certainty of relying on PrPSc molecular

type alone when considering the possibility of BSE
infection

or secondary transmission in humans who have a

genotype other than methionine at codon 129 of the

PRNP gene. In this context it is interesting to note
that this

minority type 1B component resembles the type 5 PrPSc

described previously to characterize vCJD transmission

into certain humanized PRNP129VV transgenic mouse

models.12,20 This apparently abrupt change in molecular

phenotype might represent a selection process imposed

by this particular transgenic mouse model. Irrespective of

whether this proves to be the case, the results shown

here point to further complexities in the relationship
between

the physico-chemical properties of the prion protein,

human disease phenotype, and prion agent strain.

Acknowledgments


snip...


Type 1 PrPSc in Variant Creutzfeldt-Jakob Disease 157

AJP January 2006, Vol. 168, No. 1 ...TSS



http://ajp.amjpathol.org/cgi/content/abstract/168/1/151maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=prion&searchid=1136646133963_237&FIRSTINDEX=0&volume=168&issue=1&journalcode=amjpathol




Neuropathology and Applied Neurobiology

(2005),

31

, 565-579 doi: 10.1111/j.1365-2990.2005.00697.x

© 2005 Blackwell Publishing Ltd

565

Blackwell Science, LtdOxford, UKNANNeuropathology and
Applied Neurobiology0305-1846Blackwell Publishing Ltd, 2005

316565579

Review article

Phenotypic variability in human prion diseases

J. W. Ironside, D. L. Ritchie and M. W. Head

National Creutzfeldt-Jakob Disease Surveillance Unit,
Division of Pathology, University of Edinburgh,
Edinburgh, UK

J. W. Ironside, D. L. Ritchie and M. W. Head (2005)

Neuropathology and Applied Neurobiology

31,

565-579

Phenotypic variability in human prion diseases

Human prion diseases are rare neurodegenerative disorders

that can occur as sporadic, familial or acquired disorders.

Within each of these categories there is a wide range

of phenotypic variation that is not encountered in other

neurodegenerative disorders. The identification of the

prion protein and its key role in the pathogenesis of this

diverse group of diseases has allowed a fuller
understanding

of factors that influence disease phenotype. In particular,

the naturally occurring polymorphism at codon 129

in the prion protein gene has a major influence on the
disease

phenotype in sporadic, familial and acquired prion

diseases, although the underlying mechanisms remain

unclear. Recent technical advances have improved our

ability to study the isoforms of the abnormal prion protein

in the brain and in other tissues. This has lead to the
concept

of molecular strain typing, in which different isoforms

of the prion protein are proposed to correspond to

individual strains of the transmissible agent, each with

specific biological properties. In sporadic
Creutzfeldt-Jakob

disease there are at least six major combinations of codon

129 genotype and prion protein isotype, which appear to

relate to distinctive clinical subgroups of this disease.

However, these relationships are proving to be more complex

than first considered, particularly in cases with more

than a single prion protein isotype in the brain. Further

work is required to clarify these relationships and to

explain the mechanism of neuropathological targeting of

specific brain regions, which accounts for the diversity of

clinical features within human prion diseases.


© 2005 Blackwell Publishing Ltd, Neuropathology and
Applied Neurobiology, 31, 565-579


BSE prions propagate as either variant CJD-like or

sporadic CJD-like prion strains in transgenic mice

expressing human prion protein


The EMBO Journal Vol. 21 No. 23 pp. 6358±6366, 2002


Emmanuel A.Asante, Jacqueline M.Linehan,

Melanie Desbruslais, Susan Joiner,

Ian Gowland, Andrew L.Wood, Julie Welch,

Andrew F.Hill, Sarah E.Lloyd,

Jonathan D.F.Wadsworth and

John Collinge1

MRC Prion Unit and Department of Neurodegenerative Disease,

Institute of Neurology, University College, Queen Square,

London WC1N 3BG, UK

1Corresponding author

e-mail: [email protected].


Variant Creutzfeldt±Jakob disease (vCJD) has been

recognized to date only in individuals homozygous for

methionine at PRNP codon 129. Here we show that

transgenic mice expressing human PrP methionine

129, inoculated with either bovine spongiform

encephalopathy (BSE) or variant CJD prions, may

develop the neuropathological and molecular phenotype

of vCJD, consistent with these diseases being

caused by the same prion strain. Surprisingly, however,

BSE transmission to these transgenic mice, in

addition to producing a vCJD-like phenotype, can also

result in a distinct molecular phenotype that is
indistinguishable

from that of sporadic CJD with PrPSc

type 2. These data suggest that more than one BSEderived

prion strain might infect humans; it is therefore

possible that some patients with a phenotype consistent

with sporadic CJD may have a disease arising

from BSE exposure.


snip...


These studies further strengthen the evidence that vCJD

is caused by a BSE-like prion strain. Also, remarkably, the

key neuropathological hallmark of vCJD, the presence of

abundant ¯orid PrP plaques, can be recapitulated on BSE

or vCJD transmission to these mice. However, the most

surprising aspect of the studies was the ®nding that an

alternate pattern of disease can be induced in 129MM

Tg35 mice from primary transmission of BSE, with a

molecular phenotype indistinguishable from that of a
subtype

of sporadic CJD. This ®nding has important potential

implications as it raises the possibility that some humans

infected with BSE prions may develop a clinical disease

indistinguishable from classical CJD associated with type 2

PrPSc. This is, in our experience, the commonest molecular

sub-type of sporadic CJD. In this regard, it is of interest

that the reported incidence of sporadic CJD has risen
in the

UK since the 1970s (Cousens et al., 1997). This has been

attributed to improved case ascertainment, particularly as

much of the rise is reported from elderly patients and

similar rises in incidence were noted in other European

countries without reported BSE (Will et al., 1998).

However, it is now clear that BSE is present in many

European countries, albeit at a much lower incidence than

was seen in the UK. While improved ascertainment is

likely to be a major factor in this rise, that some of
these

additional cases may be related to BSE exposure cannot be

ruled out. It is of interest in this regard that a 2-fold

increase in the reported incidence of sporadic CJD in 2001

has recently been reported for Switzerland, a country that

had the highest incidence of cattle BSE in continental

Europe between 1990 and 2002 (Glatzel et al., 2002). No

epidemiological case±control studies with strati®cation of

CJD cases by molecular sub-type have yet been reported.

It will be important to review the incidence of sporadic

CJD associated with PrPSc type 2 and other molecular
subtypes

in both BSE-affected and unaffected countries in the


light of these ®ndings. If human BSE prion infection can

result in propagation of type 2 PrPSc, it would be expected

that such cases would be indistinguishable on clinical,

pathological and molecular criteria from classical CJD. It

may also be expected that such prions would behave

biologically like those isolated from humans with sporadic

CJD with type 2 PrPSc. The transmission properties of

prions associated with type 2 PrPSc from BSE-inoculated

129MM Tg35 mice are being investigated by serial

passage.

We consider these data inconsistent with contamination

of some of the 129MM Tg35 mice with sporadic CJD

prions. These transmission studies were performed according

to rigorous biosafety protocols for preparation of

inocula and both the inoculation and care of mice, which

are all uniquely identi®ed by sub-cutaneous transponders.

However, crucially, the same BSE inocula have been used

on 129VV Tg152 and 129MM Tg45 mice, which are

highly sensitive to sporadic CJD but in which such

transmissions producing type 2 PrPSc were not observed.

Furthermore, in an independent experiment, separate

inbred lines of wild-type mice, which are highly resistant

to sporadic CJD prions, also propagated two distinctive

PrPSc types on challenge with either BSE or vCJD. No

evidence of spontaneous prion disease or PrPSc has been

seen in groups of uninoculated or mock-inoculated aged

129MM Tg35 mice.

While distinctive prion isolates have been derived from

BSE passage in mice previously (designated 301C and

301V), these, in contrast to the data presented here, are

propagated in mice expressing different prion proteins

(Bruce et al., 1994). It is unclear whether our ®ndings

indicate the existence of more than one prion strain in

individual cattle with BSE, with selection and preferential

replication of distinct strains by different hosts, or that

`mutation' of a unitary BSE strain occurs in some types of

host. Western blot analysis of single BSE isolates has not

shown evidence of the presence of a proportion of

monoglycosylated dominant PrPSc type in addition to the

diglycosylated dominant pattern (data not shown).

Extensive strain typing of large numbers of individual

BSE-infected cattle either by biological or molecular

methods has not been reported.

Presumably, the different genetic background of the

different inbred mouse lines is crucial in determining

which prion strain propagates on BSE inoculation. The

transgenic mice described here have a mixed genetic

background with contributions from FVB/N, C57BL/6 and

129Sv inbred lines; each mouse will therefore have a

different genetic background. This may explain the

differing response of individual 129MM Tg35 mice, and

the difference between 129MM Tg35 and 129MM Tg45

mice, which are, like all transgenic lines, populations

derived from single founders. Indeed, the consistent

distinctive strain propagation in FVB and C57BL/6 versus

SJL and RIIIS lines may allow mapping of genes relevant

to strain selection and propagation, and these studies
are in

progress.

That different prion strains can be consistently isolated

in different inbred mouse lines challenged with BSE

prions argues that other species exposed to BSE may

develop prion diseases that are not recognizable as being

caused by the BSE strain by either biological or molecular

strain typing methods. As with 129MM Tg35 mice, the

prions replicating in such transmissions may be
indistinguishable

from naturally occurring prion strains. It

remains of considerable concern whether BSE has transmitted

to, and is being maintained in, European sheep

¯ocks. Given the diversity of sheep breeds affected by

scrapie, it has to be considered that some sheep might have

become infected with BSE, but propagated a distinctive

strain type indistinguishable from those of natural sheep

scrapie. ...


The EMBO Journal Vol. 21 No. 23 pp. 6358±6366, 2002

6358 ãEuropean Molecular Biology Organization





http://embojournal.npgjournals.com/cgi/reprint/21/23/6358






J Neuropsychiatry Clin Neurosci 17:489-495, November 2005
doi: 10.1176/appi.neuropsych.17.4.489
© 2005 American Psychiatric Publishing, Inc.


Psychiatric Manifestations of Creutzfeldt-Jakob
Disease: A 25-Year Analysis
Christopher A. Wall, M.D., Teresa A. Rummans, M.D.,
Allen J. Aksamit, M.D.,
Lois E. Krahn, M.D. and V. Shane Pankratz, Ph.D.
Received April 20, 2004; revised September 9, 2004;
accepted September 13,
2004. From the Mayo Clinic, Department of Psychiatry
and Psychology,
Rochester, Minnesota; Mayo Clinic, Department of
Neurology, Rochester,
Minnesota. Address correspondence to Dr. Wall, Mayo
Clinic, Department of
Psychiatry and Psychology, Mayo Building-W11A, 200
First St., SW, Rochester,
MN 55905; [email protected]. (E-mail).

This study characterizes the type and timing of
psychiatric manifestations
in sporadic Creutzfeldt-Jakob disease (sCJD).
Historically, sCJD has been
characterized by prominent neurological symptoms, while
the variant form
(vCJD) is described as primarily psychiatric in
presentation and course: A
retrospective review of 126 sCJD patients evaluated at
the Mayo Clinic from
1976-2001 was conducted. Cases were reviewed for
symptoms of depression,
anxiety, psychosis, behavior dyscontrol, sleep
disturbances, and
neurological signs during the disease course. Eighty
percent of the cases
demonstrated psychiatric symptoms within the first 100
days of illness, with
26% occurring at presentation. The most commonly
reported symptoms in this
population included sleep disturbances, psychotic
symptoms, and depression.
Psychiatric manifestations are an early and prominent
feature of sporadic
CJD, often occurring prior to formal diagnosis.


snip...


CONCLUSIONS

Historically, psychiatric manifestations have been
described as a relatively
infrequent occurrence in the sporadic form of
creutzfeldt-Jakob disease.
However, our findings suggest otherwise. In this study,
a vast majority of
the cases were noted to have at least one psychiatric
symptom during the
course of illness, with nearly one-quarter occurring in
the prodromal or
presenting phase of the illness. After comparing the
frequency of
neuropsychiatric symptoms in sporadic CJD to studies
describing the variant
form of CJD, we found that there are fewer clinical
differences than
previously reported.5-7 While the age of patients
with vCJD presentation
is significantly younger and the course of illness is
longer, the type and
timing of psychiatric manifestations appear similar
between these two
diseases. ...snip...




http://neuro.psychiatryonline.org/cgi/content/abstract/17/4/489





Personal Communication


-------- Original Message --------



Subject: re-BSE prions propagate as

either variant CJD-like or sporadic CJD Date: Thu, 28
Nov 2002 10:23:43

-0000 From: "Asante, Emmanuel A" To:
"'[email protected]'"

Dear Terry,

I have been asked by Professor Collinge to respond to
your request. I am

a Senior Scientist in the MRC Prion Unit and the lead
author on the

paper. I have attached a pdf copy of the paper for your
attention. Thank

you for your interest in the paper.

In respect of your first question, the simple answer
is, yes. As you

will find in the paper, we have managed to associate
the alternate

phenotype to type 2 PrPSc, the commonest sporadic CJD.

It is too early to be able to claim any further
sub-classification in

respect of Heidenhain variant CJD or Vicky Rimmer's
version. It will

take further studies, which are on-going, to establish
if there are

sub-types to our initial finding which we are now
reporting. The main

point of the paper is that, as well as leading to the
expected new

variant CJD phenotype, BSE transmission to the
129-methionine genotype

can lead to an alternate phenotype which is
indistinguishable from type

2 PrPSc.



I hope reading the paper will enlighten you more on the
subject. If I

can be of any further assistance please to not hesitate
to ask. Best wishes.



Emmanuel Asante

<> ____________________________________

Dr. Emmanuel A Asante MRC Prion Unit & Neurogenetics
Dept. Imperial

College School of Medicine (St. Mary's) Norfolk Place,
LONDON W2 1PG

Tel: +44 (0)20 7594 3794 Fax: +44 (0)20 7706 3272 email:

[email protected]. (until 9/12/02)

New e-mail: [email protected]. (active from now)

____________________________________TSS




Human Prion Protein with

Valine 129 Prevents Expression

of Variant CJD Phenotype


Jonathan D. F. Wadsworth, Emmanuel A. Asante,

Melanie Desbruslais, Jacqueline M. Linehan, Susan Joiner,

Ian Gowland, Julie Welch, Lisa Stone, Sarah E. Lloyd,

Andrew F. Hill,* Sebastian Brandner, John Collinge.

Variant Creutzfeldt-Jakob disease (vCJD) is a unique
and highly distinctive

clinicopathological and molecular phenotype of human
prion disease

associated with infection with bovine spongiform
encephalopathy (BSE)-like

prions. Here, we found that generation of this
phenotype in transgenic mice

required expression of human prion protein (PrP) with
methionine 129.

Expression of human PrP with valine 129 resulted in a
distinct phenotype and,

remarkably, persistence of a barrier to transmission of
BSE-derived prions on

subpassage. Polymorphic residue 129 of human PrP
dictated propagation of

distinct prion strains after BSE prion infection. Thus,
primary and secondary

human infection with BSE-derived prions may result in
sporadic CJD-like or

novel phenotypes in addition to vCJD, depending on the
genotype of the prion

source and the recipient.


snip...


3 DECEMBER 2004 VOL 306 SCIENCE




http://www.sciencemag.org




Characterization of two distinct prion strains

derived from bovine spongiform encephalopathy

transmissions to inbred mice


Sarah E. Lloyd, Jacqueline M. Linehan, Melanie Desbruslais,

Susan Joiner, Jennifer Buckell, Sebastian Brandner,

Jonathan D. F. Wadsworth and John Collinge

Correspondence

John Collinge

[email protected].

MRC Prion Unit and Department of Neurodegenerative
Disease, Institute of Neurology,

University College, London WC1N 3BG, UK

Received 9 December 2003

Accepted 27 April 2004

Distinct prion strains can be distinguished by
differences in incubation period, neuropathology

and biochemical properties of disease-associated prion
protein (PrPSc) in inoculated mice.

Reliable comparisons of mouse prion strain properties
can only be achieved after passage in

genetically identical mice, as host prion protein
sequence and genetic background are known

to modulate prion disease phenotypes. While multiple
prion strains have been identified in

sheep scrapie and Creutzfeldt-Jakob disease, bovine
spongiform encephalopathy (BSE) is

thought to be caused by a single prion strain. Primary
passage of BSE prions to different lines

of inbred mice resulted in the propagation of two
distinct PrPSc types, suggesting that two

prion strains may have been isolated. To investigate
this further, these isolates were

subpassaged in a single line of inbred mice (SJL) and
it was confirmed that two distinct prion

strains had been identified. MRC1 was characterized by
a short incubation time (110±3 days),

a mono-glycosylated-dominant PrPSc type and a
generalized diffuse pattern of PrP-immunoreactive

deposits, while MRC2 displayed a much longer incubation
time (155±1 days),

a di-glycosylated-dominant PrPSc type and a distinct
pattern of PrP-immunoreactive deposits

and neuronal loss. These data indicate a crucial
involvement of the host genome in modulating

prion strain selection and propagation in mice. It is
possible that multiple disease phenotypes

may also be possible in BSE prion infection in humans
and other animals.


snip...


Journal of General Virology (2004), 85, 2471-2478 DOI
10.1099/vir.0.79889-0




http://vir.sgmjournals.org/cgi/content/abstract/85/8/2471





Medical Sciences
Identification of a second bovine amyloidotic
spongiform encephalopathy: Molecular similarities with
sporadic Creutzfeldt-Jakob disease

Cristina Casalone *, Gianluigi Zanusso , Pierluigi
Acutis *, Sergio Ferrari , Lorenzo Capucci , Fabrizio
Tagliavini ¶, Salvatore Monaco ||, and Maria Caramelli *

*Centro di Referenza Nazionale per le Encefalopatie
Animali, Istituto Zooprofilattico Sperimentale del
Piemonte, Liguria e Valle d'Aosta, Via Bologna, 148,
10195 Turin, Italy; Department of Neurological and
Visual Science, Section of Clinical Neurology,
Policlinico G.B. Rossi, Piazzale L.A. Scuro, 10, 37134
Verona, Italy; Istituto Zooprofilattico Sperimentale
della Lombardia ed Emilia Romagna, Via Bianchi, 9,
25124 Brescia, Italy; and ¶Istituto Nazionale
Neurologico "Carlo Besta," Via Celoria 11, 20133 Milan,
Italy


Edited by Stanley B. Prusiner, University of
California, San Francisco, CA, and approved December
23, 2003 (received for review September 9, 2003)

Transmissible spongiform encephalopathies (TSEs), or
prion diseases, are mammalian neurodegenerative
disorders characterized by a posttranslational
conversion and brain accumulation of an insoluble,
protease-resistant isoform (PrPSc) of the host-encoded
cellular prion protein (PrPC). Human and animal TSE
agents exist as different phenotypes that can be
biochemically differentiated on the basis of the
molecular mass of the protease-resistant PrPSc
fragments and the degree of glycosylation.
Epidemiological, molecular, and transmission studies
strongly suggest that the single strain of agent
responsible for bovine spongiform encephalopathy (BSE)
has infected humans, causing variant Creutzfeldt-Jakob
disease. The unprecedented biological properties of the
BSE agent, which circumvents the so-called "species
barrier" between cattle and humans and adapts to
different mammalian species, has raised considerable
concern for human health. To date, it is unknown
whether more than one strain might be responsible for
cattle TSE or whether the BSE agent undergoes
phenotypic variation after natural transmission. Here
we provide evidence of a second cattle TSE. The
disorder was pathologically characterized by the
presence of PrP-immunopositive amyloid plaques, as
opposed to the lack of amyloid deposition in typical
BSE cases, and by a different pattern of regional
distribution and topology of brain PrPSc accumulation.
In addition, Western blot analysis showed a PrPSc type
with predominance of the low molecular mass glycoform
and a protease-resistant fragment of lower molecular
mass than BSE-PrPSc. Strikingly, the molecular
signature of this previously undescribed bovine PrPSc
was similar to that encountered in a distinct subtype
of sporadic Creutzfeldt-Jakob disease.



--------------------------------------------------------------------------------

C.C. and G.Z. contributed equally to this work.

||To whom correspondence should be addressed.

E-mail: [email protected]. .

www.pnas.org/cgi/doi/10.1073/pnas.0305777101


snip...


Phenotypic Similarities Between BASE and sCJD. The
transmissibility

of CJD brains was initially demonstrated in primates
(27), and

classification of atypical cases as CJD was based on
this property

(28). To date, no systematic studies of strain typing
in sCJD have

been provided, and classification of different subtypes
is based

on clinical, neuropathological, and molecular features
(the polymorphic

PRNP codon 129 and the PrPSc glycotype) (8, 9, 15, 19).

The importance of molecular PrPSc characterization in
assessing

the identity of TSE strains is underscored by several
studies,

showing that the stability of given disease-specific
PrPSc types is

maintained upon experimental propagation of sCJD, familial

CJD, and vCJD isolates in transgenic PrP-humanized mice (8,

29). Similarly, biochemical properties of BSE- and
vCJDassociated

PrPSc molecules remain stable after passage to mice

expressing bovine PrP (30). Recently, however, it has been

reported that PrP-humanized mice inoculated with BSE
tissues

may also propagate a distinctive PrPSc type, with a
''monoglycosylated-

dominant'' pattern and electrophoretic mobility of the

unglycosylated fragment slower than that of vCJD and
BSE (31).

Strikingly, this PrPSc type shares its molecular
properties with the

a PrPSc molecule found in classical sCJD. This
observation is at

variance with the PrPSc type found in MV2 sCJD cases and in

cattle BASE, showing a monoglycosylated-dominant
pattern but

faster electrophoretic mobility of the
protease-resistant fragment

as compared with BSE. In addition to molecular properties

of PrPSc, BASE and MV2 sCJD share a distinctive pattern of

intracerebral PrP deposition, which occurs as
plaque-like and

amyloid-kuru plaques. Differences were, however,
observed in

the regional distribution of PrPSc. While inMV2 sCJD
cases the

largest amounts of PrPSc were detected in the cerebellum,

brainstem, and striatum, in cattle BASE these areas
were less

involved and the highest levels of PrPSc were recovered
from the

thalamus and olfactory regions.

In conclusion, decoding the biochemical PrPSc signature of

individual human and animal TSE strains may allow the
identification

of potential risk factors for human disorders with

unknown etiology, such as sCJD. However, although BASE and

sCJD share several characteristics, caution is dictated
in assessing

a link between conditions affecting two different mammalian

species, based on convergent biochemical properties of
diseaseassociated

PrPSc types. Strains of TSE agents may be better

characterized upon passage to transgenic mice. In the
interim

until this is accomplished, our present findings
suggest a strict

epidemiological surveillance of cattle TSE and sCJD
based on

molecular criteria.




http://www.pnas.org/cgi/reprint/0305777101v1



[Docket No. 03-025IFA] FSIS Prohibition of the Use of Specified Risk Materials for Human Food and Requirement for the Disposition of Non-Ambulatory Disabled Cattle

03-025IFA
03-025IFA-2
Terry S. Singeltary


Page 1 of 17

From: Terry S. Singeltary Sr. [[email protected]]

Sent: Thursday, September 08, 2005 6:17 PM

To: [email protected].

Subject: [Docket No. 03-025IFA] FSIS Prohibition of the Use of Specified Risk Materials for Human Food and Requirements

for the Disposition of Non-Ambulatory Disabled Cattle

Greetings FSIS,

I would kindly like to submit the following to [Docket No. 03-025IFA] FSIS Prohibition of the Use of Specified Risk Materials for Human Food and

Requirements for the Disposition of Non-Ambulatory Disabled Cattle

THE BSE/TSE SUB CLINICAL Non-Ambulatory Disabled Cattle

Broken bones and such may be the first signs of a sub clinical BSE/TSE Non-Ambulatory Disabled Cattle ;

SUB CLINICAL PRION INFECTION

MRC-43-00

Issued: Monday, 28 August 2000

NEW EVIDENCE OF SUB-CLINICAL PRION INFECTION: IMPORTANT RESEARCH

FINDINGS RELEVANT TO CJD AND BSE


Terry S. Singeltary Sr.

P.O. Box 42

Bacliff, Texas USA 77518

9/13/2005


snip...


http://www.fsis.usda.gov/OPPDE/Comments/03-025IFA/03-025IFA-2.pdf





SNIP...END...TSS




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