Thursday, March 30, 2017

Amyloid‑β accumulation in the CNS in human growth hormone recipients in the UK

Amyloid‑β accumulation in the CNS in human growth hormone recipients in the UK 

Diane L. Ritchie1 · Peter Adlard2 · Alexander H. Peden1 · Suzanne Lowrie1 · Margaret Le Grice1 · Kimberley Burns1 · Rosemary J. Jackson3 · Helen Yull1 · Michael J. Keogh4 · Wei Wei5 · Patrick F. Chinnery5 · Mark W. Head1 · James W. Ironside1 

Received: 15 February 2017 / Revised: 15 March 2017 / Accepted: 18 March 2017 © The Author(s) 2017. This article is an open access publication

Abstract Human-to-human transmission of Creutzfeldt– Jakob disease (CJD) has occurred through medical procedures resulting in iatrogenic CJD (iCJD). One of the commonest causes of iCJD was the use of human pituitary-derived growth hormone (hGH) to treat primary or secondary growth hormone deficiency. As part of a comprehensive tissue-based analysis of the largest cohort yet collected (35 cases) of UK hGH-iCJD cases, we describe the clinicopathological phenotype of hGH-iCJD in the UK. In the 33/35 hGH-iCJD cases with sufficient paraffin-embedded tissue for full pathological examination, we report the accumulation of the amyloid beta (Aβ) protein associated with Alzheimer’s disease (AD) in the brains and cerebral blood vessels in 18/33 hGH-iCJD patients and for the first time in 5/12 hGH recipients who died from causes other than CJD. Aβ accumulation was markedly less prevalent in age-matched patients who died from sporadic CJD and variant CJD. These results are consistent with the hypothesis that Aβ, which can accumulate in the pituitary gland, was present in the inoculated hGH preparations and had a seeding effect in the brains of around 50% of all hGH recipients, producing an AD-like neuropathology and cerebral amyloid angiopathy (CAA), regardless of whether CJD neuropathology had occurred. These findings indicate that Aβ seeding can occur independently and in the absence of the abnormal prion protein in the human brain. Our findings provide further evidence for the prion-like seeding properties of Aβ and give insights into the possibility of iatrogenic transmission of AD and CAA. 

Keywords Amyloid β · Iatrogenic Creutzfeldt–Jakob disease · Human growth hormone · Prion protein · Cerebral amyloid angiopathy · Neuropathology

snip...

Discussion 

This study provides a detailed description of the pathological phenotype of the largest series of iCJD cases (35 cases) occurring in recipients of hGH in the UK (or indeed any country). In doing so, we extend our earlier findings on the neuropathological phenotype of 21 (with frozen tissue) of these 35 cases, described as part of a thorough molecular and genetic analysis of UK hGH-iCJD cases [57]. Perhaps more importantly, it also provides a thorough investigation of the presence of Aβ, phospho-tau, α-synuclein and TDP- 43 in the hGH-iCJD cases and in non-iCJD hGH recipients to establish whether there is evidence of iatrogenic seeding of these disease-associated proteins and whether this is independent of CJD transmission [28, 29].

Neuropathological phenotypes of UK hGH‑iCJD patients and comparison with sCJD 

Iatrogenic CJD in hGH recipients is thought to result from contamination of hGH preparations with prions present in the pituitary gland collected from hGH extraction. PrPres has been detected in the pituitary gland in sCJD and vCJD patients [52] and, as reported in this study, in the pituitary gland in patients with hGH-iCJD. The most likely source of prions in hGH preparations is sCJD, which is the commonest form of human prion disease, occurring most frequently in elderly patients, who accounted for the majority of the UK hospital autopsies that were the main source of pituitary glands collected for hGH extraction. The pathological phenotype in sCJD is determined largely by the PRNP codon 129 genotype of the patient and the PrPres isoform in the brain [48]. The results from this study indicate that hGH-iCJD is subject to similar influences. The majority of the 35 hGH-iCJD cases showed a similar neuropathological phenotype to the recognised sCJD subtypes (Online Resource Table 1). All PRNP codon 129 VV UK hGH-iCJD show a pathological phenotype closely similar to the sCJD VV2 subtype. Of the 15 PRNP codon 129 MV hGH-iCJD cases, 14 show a pathological phenotype similar to the sCJD MV2K subtype, with the presence of kuru plaques. In contrast, the PRNP codon 129 MM subgroup show a divergent phenotype, with two of the four MM cases resembling the sCJD MM1 subtype in terms of neuropathology. The other two PRNP codon MM cases had kuru plaques and plaque-like deposits in the CNS. In our earlier publication, we suggest that this divergent neuropathological phenotype, combined with an intermediate (20 kDa) brain PrPres isoform, may be a reflection of incomplete adaptation of the infecting V2 prion strain in the PRNP codon 129 MM host [57]. This pathology has not been described in UK cases of either hDM-iCJD or sCJD with a PRNP codon 129 MM genotype, but they have been described in cases of hDM-iCJD in Japan in PRNP codon 129 MM genotype patients. Kobayashi et al. [33] have suggested that the combination of a PRNP codon 129 genotype and the presence of kuru plaques in the cerebellum and cerebral cortex in a patient with apparently sporadic CJD should lead to a suspicion of an iatrogenic route of infection. In view of these results, particular care must be taken in interpreting the neuropathological findings in the five cases in which neither PRNP codon 129 genotype nor PrPres isoform data are available (Online Resource Table 1). Case hGH-iCJD33 had a pathology that resembled the sCJD MV2K histotype; however, the possibility that this case could have a MM genotype cannot be excluded. Even if this were so, over 90% (32/35) of the UK hGH-iCJD cases would have neuropathological and biochemical features that are indistinguishable from one of the sCJD histotypes. With such close similarities in the neuropathological phenotypes between sCJD and hGH-iCJD cases, a detailed clinical history of any potential iatrogenic exposure to CJD prions is essential for diagnosis.

Peripheral pathogenesis in hGH‑iCJD The peripheral pathogenesis of hGH-iCJD following inoculation of infected hGH preparations by intramuscular and subcutaneous injection is not known. Some prion strains (including vCJD) replicate in lymphoid tissues before invading the CNS. Neuroinvasion may occur via the bloodborne route, or by slow retrograde spread along autonomic nerve to the spinal cord and/or brainstem, then spreading to the brain itself [40]. These complex mechanisms partly explain the lengthy incubation period in prion diseases [32]. The results of this study on a limited range of nonCNS tissues available give some support for involvement of the peripheral nervous system (nerves, dorsal root ganglia and trigeminal ganglia) and, for the first time, involvement of lymphoid tissues in a single hGH-iCJD case. It may be that hGH-iCJD has some similarities to vCJD in terms of its peripheral pathogenesis, but the levels of PrPres detected in lymphoid and peripheral nervous system structures appear lower and more restricted in distribution than in vCJD.

CNS Aβ in hGH‑iCJD and hGH control cases and associations with Alzheimer’s disease The possibility of transmission of other neurotoxic proteins that accumulate in the pituitary gland was supported by recent evidence of Aβ seeding in the brains of 4/8 hGH recipients who died with iCJD [29]. However, all eight patients had clinical iCJD, raising the possibility that Aβ pathology resulted from cross-seeding, or was in some other way contingent on the iatrogenic transmission of CJD. Aβ seeding around PrPSc deposits has been reported in human prion disease, particularly in genetic prion diseases associated with the formation of PrPSc amyloid plaques [9, 27, 44]. In this study, examining a significantly larger number of hGH-iCJD cases (including cases from all PRNP codon 129 genotypes), CNS Aβ accumulation was identified in the cerebral cortex and/or meningeal and intraparenchymal blood vessels (including capillaries) in 18/33 hGH-iCJD. Crucially, our study reports Aβ accumulation in 5/12 hGH recipient who did not die with iCJD, indicating that the Aβ pathology found in hGH recipients is independent of the development of clinical CJD and the pathological changes that underlie it. Aβ pathology was similar in both hGH-iCJD and hGH control patients, occurring as parenchymal deposits (diffuse subpial deposits, diffuse plaques and cored/neuritic plaques) and as CAA, or both parenchymal and CAA. Overall, no major differences are observed in the nature or range of severity of the pathology between the hGH-iCJD and hGH control groups. The parenchymal Aβ deposits in both groups also had similar astrocytic and microglial reactions, which have not been reported in previous studies on CNS Aβ accumulation in cases of iCJD [16, 29, 36].

While the parenchymal Aβ deposits in the brains of the hGH recipients show similarities to the deposits found in Alzheimer’s disease, the distribution of the Aβ pathology does not appear to resemble the pattern that is characteristic of Alzheimer’s disease, but shows a distribution more similar to that previously described in hDM-iCJD [36]. Other distinctions between the Aβ-positive hGH recipients and Alzheimer’s disease patients include the notable absence of neurofibrillary tangles, a paucity of phosphotau-positive neurites around neuritic plaques, the young age at death of the hGH recipients and the absence of a clinical history of slowly progressive cognitive impairment. All the hGH recipients with CNS Aβ accumulation in our study were under the age of 45 years at death, most of whom did not have the APOE-ɛ3/4 genotype or apoE-4 phenotype on immunohistochemistry. In a recent study of the brains of 154 individuals between the ages of 30 and 50 years [53], Aβ deposition was not identified in any individuals under the age of 40 years, but was present in the brains of 13 individuals aged between 40–49 years in the form of diffuse plaques throughout the cerebral cortex. None of the cases with Aβ positivity had clinical evidence of dementia or mild cognitive impairment. All individuals with Aβ positivity carried 1 or 2 APOE ɛ4 alleles; however, of the 28 individuals aged 40–50 years with the APOE-ɛ3/4 genotype, 10 (36%) had Aβ deposition in the brain, but 18 (64%) did not, indicating that the Aβ deposition in the brain before the age of 50 years may occur in only around 1/3 of non-demented individuals with the APOE-ɛ3/4 genotype [53].

Most of the cases in this study with CAA had the APOE-ɛ3/3 genotype, including the two cases with capillary CAA. The hGH-iCJD case with the greatest amount of Aβ positivity (hGH-iCJD18) had the APOE-ɛ3/3 genotype (combined ABC and CAA score 8), as did the hGH control case (hGH-control11) with the greatest amount of Aβ accumulation in the CNS (combined ABC and CAA score 11). The single sCJD case with CAA had the APOE-ɛ3/4 genotype, while the two vCJD cases with diffuse Aβ parenchymal deposits comprised one case with the APOE-ɛ3/4 genotype and one case with the APOE-ɛ2/3 genotype. The latter (vCJD 27) was identified on exome sequencing to have the PSEN1 p.E318G variant that increases the risk of AD in APOE-ɛ4 carriers (but possibly not relevant in the APOE ɛ2/3 genotype) [2], and the −48 C/T polymorphism in the PSEN1 promoter that is associated with an increased risk of AD and an increased Aβ load in the brain [37], which might be of relevance to the finding of sparse diffuse Aβ brain parenchymal deposits at 30 years of age. Overall, our results indicate no apparent influence of the APOE-ɛ3/4 genotype or the apoE-4 phenotype on the presence of either parenchymal or vascular Aβ accumulation in the groups of hGH-iCJD and hGH control patients, which include a patient as young as 20 years of age with CAA and an apoE- 4-ve phenotype on immunohistochemistry. 

Factors influencing CNS Aβ accumulation in hGH recipients

In considering the accumulation of Aβ in the CNS in hGH recipients, the assumption is that the source of the Aβ originates from Aβ deposits in the pituitary glands collected for hGH extraction [28, 29]. However, our investigations on limited numbers of non-CNS tissues yielded no evidence in favour of the involvement of these non-CNS tissues in the spread of Aβ to the CNS. In this study, no significant differences were found between the Aβ-positive and Aβ-negative cases in hGH recipients in terms of the time period or duration of their hGH treatment, although there was a trend for the hGH controls with Aβ pathology to have been treated in an earlier time period and for longer than the Aβ negative cases. The most severe Aβ pathology, tended to occur in the patients who had survived for the longest after the end of their hGH treatment, perhaps reflecting slowly progressive Aβ seeding and propagation in the CNS prior to death. The lack of any relationship between the duration of hGH treatment and the development of Aβ pathology may be taken to indicate that the amount of Aβ contaminating the hGH inocula was variable and unpredictable. The same could be said for the lack of a relationship between the duration of hGH treatment and the development of iCJD; prion contamination of the hGH inocula also having been variable and unpredictable. 

All hGH recipients who developed iCJD in the UK, were treated for at least 6 months between 1967 and 1980 with hGH produced by the modified Wilhelmi protocol [64]. This study has found that all the hGH recipients with CNS Aβ accumulation had also been treated (for varying periods of time) with this same preparation. While not all patients treated with this preparation developed either hGH-iCJD or CNS Aβ accumulation, it is important to note that the four patients who were never treated with this hGH preparation did not develop either iCJD or show CNS Aβ accumulation (Online Resource Table 2). Subsequent studies of the hGH produced by the modified Wilhelmi protocol were reported in 1982 [63]. Using polyacrylamide gel electrophoresis and amino acid analysis of the high molecular weight fraction of this preparation this study found “aggregated hGH as well as other material not separated from hGH by the purification procedure”. While it is highly likely that this “other material” included PrPSc, it may also have included Aβ aggregates that were neither sufficiently removed nor denatured by the Wilhelmi protocol for them to lose their capacity to act as a propagon [13].

snip...

Questions have been raised on the clinical background of the patients included in the study by Jaunmuktane et al., suggesting that the pre-existing and underlying conditions causing hGH deficiency in this patient cohort “could by themselves lead to Aβ pathology and abnormal brain structure” [15]. In the 33 patients analysed for Aβ deposits in this study, we found no clinical history or neuropathological evidence of traumatic brain injury as the cause of the hGH deficiency. Of the 13 hGH recipients who had brain tumours, three had received post-operative radiotherapy (Online Resource Table 2), none of whom had Aβ deposition in the CNS. In addition, no evidence of the more generalised disorders that can be associated with Aβ deposition in the CNS (as suggested by Feeney et al. [15]) such as epilepsy, fragile X syndrome, Down’s syndrome or Parkinson’s disease were found (Online Resource Table 2). Furthermore, the morphology and distribution of Aβ lesions and relative lack of phospho-tau pathology argue against an underlying traumatic aetiology for the Aβ pathology reported in this study. In the two cases with incidental focal isolated phospho-tau pathology (pretangles and occasional tangles) unrelated to areas of Aβ deposition, the localised abnormalities did not match the recent proposed diagnostic criteria for chronic traumatic encephalopathy [42] and did not resemble the early stages of tauopathies such as corticobasal degeneration [67]. In hGH control10, the accompanying neuronal loss and gliosis indicates longstanding focal brain tissue damage that may relate to previous neurosurgery. The pretangles in hGH-iCJD 31 are more difficult to explain, but might represent a local reaction to a previous focal insult no longer apparent in the post-mortem brain. Pretangles in the brains of very young individuals were identified in a large study by Braak et al. [7] in subcortical sites, but not in the cerebral cortex. However, subcortical pretangles or tangles were not found in this or any other case examined. 

Aβ accumulation in the CNS has been reported in both hGH-iCJD cases [29] and hDM-iCJD cases [16, 22, 36]. However, the level of detail in these reports, varies in both the descriptive pathology of the CNS and the results of associated genetic investigations. This study adds considerably to these reports in terms of the number of cases studied, the inclusion of hGH control cases without iCJD, and in the young age of the patients included. The detailed neuropathological description provided is comparable with that in Kovacs et al. [36], particularly in relation to the nature and localisation of the Aβ deposition and its relationship to Alzheimer’s disease, but still falls short of resembling a full AD neuropathological phenotype. Table 3 summarises the key findings in these reports and compares their findings with the findings in this study.

Conclusions and implications of results 

This comprehensive study on the largest number of hGHiCJD cases reported to date, indicates that Aβ can behave as a propagon in humans, able to spread to the CNS following intramuscular or subcutaneous injection and subsequently seed in the parenchyma of the brain and in cerebral blood vessels, but does not result in clinical Alzheimer’s disease or any other apparent clinical manifestations in these patients. CNS Aβ accumulation occurred in around 50% of hGH-iCJD and hGH control cases, and is therefore not dependent on co-existing PrPSc accumulation or other CJD pathology. The proposed behaviour of Aβ as a propagon in humans has broader implications including potential exposure to Aβ, for example in the reuse of Aβ-contaminated neurosurgical instruments, previously used on the brains of elderly patients, or via blood transfusions from elderly donors who may have increased levels of plasma Aβ [3]. However, recent epidemiological studies have found no evidence of either previous surgery or blood transfusion as risk factors for Alzheimer’s disease [11, 68]. These findings might also be taken to indicate that a significant number of the remaining survivors in the cohort of UK hGH recipients are at increased risk of CNS Aβ accumulation and, although they may not progress to symptomatic Alzheimer’s disease, they may subsequently develop vascular complications. The severe CAA found in the older hGH control patients in this study suggests that surviving hGH recipients may be at future risk of the complications of CAA, including spontaneous lobar cerebral haemorrhage, perivascular inflammation and cognitive impairment [17] in addition to having lived with the knowledge of an increased risk of CJD.


Alzheimer’s disease, iatrogenic, and Transmissible Spongiform Encephalopathy TSE Prion disease, that is the question ???
 
>>> The only tenable public line will be that "more research is required’’ <<<
 
>>> possibility on a transmissible prion remains open<<<
 
O.K., so it’s about 23 years later, so somebody please tell me, when is "more research is required’’ enough time for evaluation ?

[9. Whilst this matter is not at the moment directly concerned with the iatrogenic CJD cases from hgH, there remains a possibility of litigation here, and this presents an added complication. There are also results to be made available shortly (1) concerning a farmer with CJD who had BSE animals, (2) on the possible transmissibility of Alzheimer’s and (3) a CMO letter on prevention of iatrogenic CJD transmission in neurosurgery, all of which will serve to increase media interest.]

 

 
 
snip...see full Singeltary Nature comment here;
 
 
see Singeltary comments to Plos ;
 
Subject: 1992 IN CONFIDENCE TRANSMISSION OF ALZHEIMER TYPE PLAQUES TO PRIMATES POSSIBILITY ON A TRANSMISSIBLE PRION REMAINS OPEN
 
BSE101/1 0136
 
IN CONFIDENCE
 
CMO
 
From: . Dr J S Metiers DCMO
 
4 November 1992
 
TRANSMISSION OF ALZHEIMER TYPE PLAQUES TO PRIMATES
 
1. Thank you for showing me Diana Dunstan's letter. I am glad that MRC have recognised the public sensitivity of these findings and intend to report them in their proper context. 'This hopefully will avoid misunderstanding and possible distortion by the media to portray the results as having more greater significance than the findings so far justify.
 
2. Using a highly unusual route of transmission (intra-cerebral injection) the researchers have demonstrated the transmission of a pathological process from two cases one of severe Alzheimer's disease the other of Gerstmann-Straussler disease to marmosets. However they have not demonstrated the transmission of either clinical condition as the "animals were behaving normally when killed". As the report emphasises the unanswered question is whether the disease condition would have revealed itself if the marmosets had lived longer. They are planning further research to see if the conditions, as opposed to the partial pathological process, is transmissible.
 
what are the implications for public health?
 
3. The route 'of transmission is very specific and in the natural state of things highly unusual. However it could be argued that the results reveal a potential risk, in that brain tissue from these two patients has been shown to transmit a pathological process. Should therefore brain tissue from such cases be regarded as potentially infective? Pathologists, morticians, neuro surgeons and those assisting at neuro surgical procedures and others coming into contact with "raw" human brain tissue could in theory be at risk. However, on a priori grounds given the highly specific route of transmission in these experiments that risk must be negligible if the usual precautions for handling brain tissue are observed.
 
1
 
92/11.4/1.1
 
BSE101/1 0137
 
4. The other dimension to consider is the public reaction. To some extent the GSS case demonstrates little more than the transmission of BSE to a pig by intra-cerebral injection. If other prion diseases can be transmitted in this way it is little surprise that some pathological findings observed in GSS were also transmissible to a marmoset. But the transmission of features of Alzheimer's pathology is a different matter, given the much greater frequency of this disease and raises the unanswered question whether some cases are the result of a transmissible prion. The only tenable public line will be that "more research is required’’ before that hypothesis could be evaluated. The possibility on a transmissible prion remains open. In the meantime MRC needs carefully to consider the range and sequence of studies needed to follow through from the preliminary observations in these two cases. Not a particularly comfortable message, but until we know more about the causation of Alzheimer's disease the total reassurance is not practical.
 
J S METTERS Room 509 Richmond House Pager No: 081-884 3344 Callsign: DOH 832 llllYc!eS 2 92/11.4/1.2
 
 
>>> The only tenable public line will be that "more research is required’’ <<<
 
>>> possibility on a transmissible prion remains open<<<
 
O.K., so it’s about 23 years later, so somebody please tell me, when is "more research is required’’ enough time for evaluation ?
 
 Re-Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy
 
Nature 525, 247?250 (10 September 2015) doi:10.1038/nature15369 Received 26 April 2015 Accepted 14 August 2015 Published online 09 September 2015 Updated online 11 September 2015 Erratum (October, 2015)
 
snip...see full Singeltary Nature comment here;
 
 
Self-Propagative Replication of Ab Oligomers Suggests Potential Transmissibility in Alzheimer Disease
 
*** Singeltary comment PLoS ***
 
Alzheimer’s disease and Transmissible Spongiform Encephalopathy prion disease, Iatrogenic, what if ?
 
Posted by flounder on 05 Nov 2014 at 21:27 GMT
 
 
Sunday, November 22, 2015
 
*** Effect of heating on the stability of amyloid A (AA) fibrils and the intra- and cross-species transmission of AA amyloidosis Abstract
 
Amyloid A (AA) amyloidosis is a protein misfolding disease characterized by extracellular deposition of AA fibrils. AA fibrils are found in several tissues from food animals with AA amyloidosis. For hygienic purposes, heating is widely used to inactivate microbes in food, but it is uncertain whether heating is sufficient to inactivate AA fibrils and prevent intra- or cross-species transmission. We examined the effect of heating (at 60 °C or 100 °C) and autoclaving (at 121 °C or 135 °C) on murine and bovine AA fibrils using Western blot analysis, transmission electron microscopy (TEM), and mouse model transmission experiments. TEM revealed that a mixture of AA fibrils and amorphous aggregates appeared after heating at 100 °C, whereas autoclaving at 135 °C produced large amorphous aggregates. AA fibrils retained antigen specificity in Western blot analysis when heated at 100 °C or autoclaved at 121 °C, but not when autoclaved at 135 °C. Transmissible pathogenicity of murine and bovine AA fibrils subjected to heating (at 60 °C or 100 °C) was significantly stimulated and resulted in amyloid deposition in mice. Autoclaving of murine AA fibrils at 121 °C or 135 °C significantly decreased amyloid deposition. Moreover, amyloid deposition in mice injected with murine AA fibrils was more severe than that in mice injected with bovine AA fibrils. Bovine AA fibrils autoclaved at 121 °C or 135 °C did not induce amyloid deposition in mice. These results suggest that AA fibrils are relatively heat stable and that similar to prions, autoclaving at 135 °C is required to destroy the pathogenicity of AA fibrils. These findings may contribute to the prevention of AA fibril transmission through food materials to different animals and especially to humans.
 
Purchase options Price * Issue Purchase USD 511.00 Article Purchase USD 54.00
 
 
 
*** Transmission of Creutzfeldt-Jakob disease to a chimpanzee by electrodes contaminated during neurosurgery ***
 
Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC. Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
 
Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.
 
 
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
 
Singeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA
 
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
 
To the Editor: In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.
 
Terry S. Singeltary, Sr Bacliff, Tex
 
1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323.
 
 
THURSDAY, JANUARY 19, 2017 

Variant Creutzfeldt–Jakob Disease in a Patient with Heterozygosity at PRNP Codon 129


the warning shots fired over the bow of the boat that were never heard ;

PITUITARY EXTRACT 

This was used to help cows super ovulate. This tissue was considered to be of greatest risk of containing BSE and consequently transmitting the disease... 



NON-LICENSED HUMAN TISSUE DEVICES WERE NOT COMMERCIALLY AVAILABLE 

snip... 

I was quite prepared to believe in unofficial pituitary hormones, also in the 1970's, whether as described by Dr. Little, or in other circumstances, for animal use. 

snip... 

The fact that there were jars of pituitaries (or extract) around on shelves is attested by the still potent 1943 pituitaries, described in Stockell Hartree et al. (J/RF/17/291) which had come from the lab. at Mill Hill. Having taken the trouble to collect them, they were not lightly thrown out... 


3. The extraction is from a pool of pituitary glands collected from abbatoirs and the process used is unlikely to have any effect on the BSE agent. Hormones extracted from human pituitary glands have been responsible for a small number of Creutzfeldt Jacob disease in man. 


SEE LOOPHOLE ; 


SEE LOOPHOLE SHOULD BE CLOSED ; 



We have demonstrated that conventional mice inoculated with Sc237 prions harbor high levels of PrPSc and high prion titers in their brains without developing clinical signs of prion disease within their normal lifespan. These results imply the existence of subclinical prion infections that can be induced by challenge with prions from another species. However, whether or not this infectivity is classified as preclinical or subclinical, it has important public health implications. Iatrogenic transmission could occur from apparently healthy humans who may harbor high prion titers and many animal species (including sheep, pigs, and poultry) were exposed to BSE prions via contaminated feed and could have developed subclinical prion infection. It is known that BSE 

9/13/2005

Page 4 of 17 

prions retain their distinctive strain characteristics after passage in a number of other species including humans (4, 13), arguing that such BSE passaged in species other than cattle also may be pathogenic to humans. The possibility that subclinical BSE might be present in other species and thereby present a threat to human health has been raised (30) but not yet rigorously investigated. Furthermore, these data argue in favor of screening apparently healthy cattle after slaughter to investigate whether significant levels of subclinical or preclinical BSE are present.




SEE FULL TEXT ;

Thursday, April 12, 2012

*** Health professions and risk of sporadic Creutzfeldt–Jakob disease, 1965 to 2010 


Friday, January 10, 2014 

vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what it ??? 

Greetings Friends, Neighbors, and Colleagues, 



Thursday, August 13, 2015 

Iatrogenic CJD due to pituitary-derived growth hormone with genetically determined incubation times of up to 40 years 











ZOONOSIS OF THE TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION DISEASE

*** WDA 2016 NEW YORK *** We found that CWD adapts to a new host more readily than BSE and that human PrP was unexpectedly prone to misfolding by CWD prions. In addition, we investigated the role of specific regions of the bovine, deer and human PrP protein in resistance to conversion by prions from another species. We have concluded that the human protein has a region that confers unusual susceptibility to conversion by CWD prions. 

Student Presentations Session 2 

The species barriers and public health threat of CWD and BSE prions Ms. Kristen Davenport1, Dr. Davin Henderson1, Dr. Candace Mathiason1, Dr. Edward Hoover1 1Colorado State University 

Chronic wasting disease (CWD) is spreading rapidly through cervid populations in the USA. Bovine spongiform encephalopathy (BSE, mad cow disease) arose in the 1980s because cattle were fed recycled animal protein. These and other prion diseases are caused by abnormal folding of the normal prion protein (PrP) into a disease causing form (PrPd), which is pathogenic to nervous system cells and can cause subsequent PrP to misfold. CWD spreads among cervids very efficiently, but it has not yet infected humans. On the other hand, BSE was spread only when cattle consumed infected bovine or ovine tissue, but did infect humans and other species. The objective of this research is to understand the role of PrP structure in cross-species infection by CWD and BSE. To study the propensity of each species’ PrP to be induced to misfold by the presence of PrPd from verious species, we have used an in vitro system that permits detection of PrPd in real-time. We measured the conversion efficiency of various combinations of PrPd seeds and PrP substrate combinations. We observed the cross-species behavior of CWD and BSE, in addition to feline-adapted CWD and BSE. We found that CWD adapts to a new host more readily than BSE and that human PrP was unexpectedly prone to misfolding by CWD prions. In addition, we investigated the role of specific regions of the bovine, deer and human PrP protein in resistance to conversion by prions from another species. 

***We have concluded that the human protein has a region that confers unusual susceptibility to conversion by CWD prions. CWD is unique among prion diseases in its rapid spread in natural populations. BSE prions are essentially unaltered upon passage to a new species, while CWD adapts to the new species. This adaptation has consequences for surveillance of humans exposed to CWD. 

Wildlife Disease Risk Communication Research Contributes to Wildlife Trust Administration Exploring perceptions about chronic wasting disease risks among wildlife and agriculture professionals and stakeholders 


PRION 2016 TOKYO Zoonotic Potential of CWD Prions: An Update 

Ignazio Cali1, Liuting Qing1, Jue Yuan1, Shenghai Huang2, Diane Kofskey1,3, Nicholas Maurer1, Debbie McKenzie4, Jiri Safar1,3,5, Wenquan Zou1,3,5,6, Pierluigi Gambetti1, Qingzhong Kong1,5,6 1Department of Pathology, 3National Prion Disease Pathology Surveillance Center, 5Department of Neurology, 6National Center for Regenerative Medicine, Case Western Reserve University, Cleveland, OH 44106, USA. 4Department of Biological Sciences and Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada, 2Encore Health Resources, 1331 Lamar St, Houston, TX 77010 

Chronic wasting disease (CWD) is a widespread and highly transmissible prion disease in free-ranging and captive cervid species in North America. The zoonotic potential of CWD prions is a serious public health concern, but the susceptibility of human CNS and peripheral organs to CWD prions remains largely unresolved. We reported earlier that peripheral and CNS infections were detected in transgenic mice expressing human PrP129M or PrP129V. Here we will present an update on this project, including evidence for strain dependence and influence of cervid PrP polymorphisms on CWD zoonosis as well as the characteristics of experimental human CWD prions. 

PRION 2016 TOKYO In Conjunction with Asia Pacific Prion Symposium 2016 PRION 2016 Tokyo Prion 2016 


Monday, May 02, 2016 

*** Zoonotic Potential of CWD Prions: An Update Prion 2016 Tokyo *** 


Saturday, April 23, 2016 

PRION 2016 TOKYO Saturday, April 23, 2016 

SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016 Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online Taylor & Francis Prion 2016 Animal Prion Disease Workshop 

Abstracts WS-01: Prion diseases in animals and zoonotic potential 

Juan Maria Torres a, Olivier Andreoletti b, J uan-Carlos Espinosa a. Vincent Beringue c. Patricia Aguilar a, Natalia Fernandez-Borges a. and Alba Marin-Moreno a "Centro de Investigacion en Sanidad Animal ( CISA-INIA ). Valdeolmos, Madrid. Spain; b UMR INRA -ENVT 1225 Interactions Holes Agents Pathogenes. ENVT. Toulouse. France: "UR892. Virologie lmmunologie MolécuIaires, Jouy-en-Josas. France 

Dietary exposure to bovine spongiform encephalopathy (BSE) contaminated bovine tissues is considered as the origin of variant Creutzfeldt Jakob (vCJD) disease in human. To date, BSE agent is the only recognized zoonotic prion. Despite the variety of Transmissible Spongiform Encephalopathy (TSE) agents that have been circulating for centuries in farmed ruminants there is no apparent epidemiological link between exposure to ruminant products and the occurrence of other form of TSE in human like sporadic Creutzfeldt Jakob Disease (sCJD). However, the zoonotic potential of the diversity of circulating TSE agents has never been systematically assessed. The major issue in experimental assessment of TSEs zoonotic potential lies in the modeling of the ‘species barrier‘, the biological phenomenon that limits TSE agents’ propagation from a species to another. In the last decade, mice genetically engineered to express normal forms of the human prion protein has proved essential in studying human prions pathogenesis and modeling the capacity of TSEs to cross the human species barrier. To assess the zoonotic potential of prions circulating in farmed ruminants, we study their transmission ability in transgenic mice expressing human PrPC (HuPrP-Tg). Two lines of mice expressing different forms of the human PrPC (129Met or 129Val) are used to determine the role of the Met129Val dimorphism in susceptibility/resistance to the different agents. These transmission experiments confirm the ability of BSE prions to propagate in 129M- HuPrP-Tg mice and demonstrate that Met129 homozygotes may be susceptible to BSE in sheep or goat to a greater degree than the BSE agent in cattle and that these agents can convey molecular properties and neuropathological indistinguishable from vCJD. However homozygous 129V mice are resistant to all tested BSE derived prions independently of the originating species suggesting a higher transmission barrier for 129V-PrP variant. Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with ef?ciency comparable to that of cattle BSE. While the ef?ciency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice. Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion. These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and 

human prions.


why do we not want to do TSE transmission studies on chimpanzees $ 

5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis. 

snip... 

R. BRADLEY 


Title: Transmission of scrapie prions to primate after an extended silent incubation period) *** 

In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS. 

*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated. 

*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains. 


SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016 

Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online 



O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases). Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods. 

*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period, 

***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014), 

***is the third potentially zoonotic PD (with BSE and L-type BSE), 

***thus questioning the origin of human sporadic cases. We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health. 

=============== 

***thus questioning the origin of human sporadic cases*** 

***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals. 


LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ 

*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).*** 


*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies. 


WEDNESDAY, MARCH 15, 2017 

In vitro amplification of H-type atypical bovine spongiform encephalopathy by protein misfolding cyclic amplification

"When considering the atypical L-BSE and H-BSE diseases of cattle, they have been assessed in both non-human primate and transgenic mouse bioassays (with mice transgenic for human PRNP) and both model systems indicate that H-BSE and L-BSE may have increased zoonotic potential compare with C-BSE. The detection of all types of BSE is therefore of significant importance."


Monday, January 09, 2017

Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle CDC Volume 23, Number 2—February 2017


Wednesday, December 21, 2016
 
TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES 2016 ANNUAL REPORT ARS RESEARCH
 
 

Thursday, January 14, 2016 

*** Preventable Tragedies: Superbugs and How Ineffective Monitoring of Medical Device Safety Fails Patients REPORT ***

how can it be, HOW CAN IT BE $$$ not a word about CJD GSS FFI VPSPR TSE Prions that I saw...absolutely crazy, WE ARE MISSING THE BIGGER PICTURE! 

how many victims that will never be reported ??? 


Sunday, December 04, 2016

Heidenhain variant of Creutzfeldt–Jakob disease in a patient who had bovine bioprosthetic valve implantation

Year : 2016 | Volume : 64 | Issue : 10 | Page : 767-769


Sunday, January 17, 2016 

*** Of Grave Concern Heidenhain Variant Creutzfeldt Jakob Disease *** 


Wednesday, September 07, 2016 

Michigan Launches an investigation into the Detroit Medical Center dirty, broken and missing surgical instruments, what about the CJD TSE PRION iatrogenic threat past and present therefrom? 


Thursday, June 04, 2015 

Catholic Medical Center v. Civil No. 14-cv-180-JL Opinion No. 2015 DNH 110 Fireman’s Fund Insurance Company Creutzfeldt Jakob Disease TSE Prion tainted medical instruments 

UNITED STATES DISTRICT COURT DISTRICT OF NEW HAMPSHIRE


Tuesday, February 11, 2014 

Novant Health Forsyth Medical Center Information on potential CJD exposure 


Monday, February 10, 2014 

18 Forsyth Medical Center patients exposed to CJD; apology issued...OOOPS, SORRY, TOO BAD $$$ 


Thursday, January 16, 2014 

The Anspach Effort, Inc. RECALL FDA Blackmax motor had been used in a case where the patient was diagnosed with Creutzfeldt-Jacob Disease (CJD) MARYLAND HOSTPITAL 


Friday, January 10, 2014 

*** vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what it ??? ***


Thursday, January 23, 2014 

Medical Devices Containing Materials Derived from Animal Sources (Except for In Vitro Diagnostic Devices) [Docket No. FDA–2013–D–1574] 


Sunday, April 06, 2014 

SPORADIC CJD and the potential for zoonotic transmission there from, either directly or indirectly via friendly fire iatrogenic mode, evidence to date


Thursday, April 17, 2014 

Novant: Three more may have been exposed to disease CJD 


Wednesday, September 10, 2014 

Creutzfeldt-Jakob disease (CJD) biannual update (August 2014), with updated guidance on decontamination of gastrointestinal endoscopy equipment 

Research and analysis


Tuesday, August 26, 2014 

Blood reference materials from macaques infected with variant Creutzfeldt-Jakob disease agent


Wednesday, November 27, 2013 

NHS failed to sterilise surgical instruments contaminated with 'mad cow' disease


Saturday, November 16, 2013 

Management of neurosurgical instruments and patients exposed to creutzfeldt-jakob disease 2013 December 

Infect Control Hosp Epidemiol. 


Tuesday, September 24, 2013 

NORDION (US), INC., AND BIOAXONE BIOSCIENCES, INC., Settles $90M Mad Cow TSE prion Contamination Suit Cethrin(R) 

Case 0:12-cv-60739-RNS Document 1 Entered on FLSD Docket 04/26/2012 Page 1 of 15 


Thursday, September 05, 2013 

Possible Patient Exposure to Creutzfeldt-Jakob Disease Announced New Hampshire DHHS 

Press Release 


Friday, July 19, 2013 

Beaumont Hospital in Dublin assessing patients for CJD 


Monday, April 15, 2013 

Dr. Stephen B. Thacker Director Centers for Disease Control and Prevention′s Office of Science, Epidemiology and Laboratory Services (OSELS) dies from Creutzfeldt Jakob Disease CJD 


Thursday, August 02, 2012 

CJD case in Saint John prompts letter to patients Canada CJD case in Saint John prompts letter to patients 


Tuesday, July 31, 2012 

11 patients may have been exposed to fatal disease Creutzfeldt-Jakob Disease CJD Greenville Memorial Hospital 


Thursday, August 02, 2012 

CJD case in Saint John prompts letter to patients Canada CJD case in Saint John prompts letter to patients 


Saturday, February 12, 2011 

Another Pathologists dies from CJD, another potential occupational death ? 

another happenstance of bad luck, a spontaneous event from nothing, or friendly fire ??? 


Wednesday, November 30, 2011 

First iCJD Death Confirmed in Korea 


Thursday, December 08, 2011

A case of Iatrogenic Creutzfeldt Jakob Disease (iCJD) in a patient who had received a German-manufactured human dura mater graft 23 years ago 


Thursday, December 8, 2011

S. Korea confirms second case of iatrogenic Creutzfeldt-Jakob disease 48-year-old man 

2011/12/08 11:08 KST 


Monday, December 12, 2011

Second iatrogenic CJD case confirmed Korea 



Wednesday, November 09, 2016

Maine Medical Center postpones elective surgeries over suspected case of prion disease


Saturday, February 13, 2016 

The Risk of Prion Infection through Bovine Grafting Materials in dentistry 


Saturday, January 16, 2016 

Revised Preventive Measures to Reduce the Possible Risk of Transmission of Creutzfeldt-Jakob Disease and Variant Creutzfeldt-Jakob Disease by Blood and Blood Products Guidance for Industry 


Tuesday, May 26, 2015 

Minimise transmission risk of CJD and vCJD in healthcare settings Last updated 15 May 2015 


Friday, October 09, 2015 

*** An alarming presentation level II trauma center of Creutzfeldt-Jakob disease following a self-inflicted gunshot wound to the head 


Wednesday, January 06, 2016 

CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE U.K. 23rd ANNUAL REPORT 2014 (published 18th November 2015) 


Thursday, March 17, 2016 

Preliminary Diagnosis Creutzfeldt-Jakob Disease Confirmed in Patient that had Lumbar Puncture at Washington Regional Medical Center


all iatrogenic cjd is, is sporadic cjd, until the iatrogenic event is discovered, traced back, documented in the Academic domain, and then put into the public domain and documented as an iatrogenic CJD event. that’s why 85%+ of all human TSE prion disease is still sporadic CJD. problem solved $$$ 

PLEASE REMEMBER, IN 55 YEARS AND OLDER, THE RATE OF DOCUMENTED CJD JUMPS TO ONE IN 9,000. 

Thursday, September 10, 2015 

25th Meeting of the Transmissible Spongiform Encephalopathies Advisory Committee Food and Drug Administration Silver Spring, Maryland June 1, 2015 


Saturday, February 13, 2016 

The Risk of Prion Infection through Bovine Grafting Materials in dentistry 


Monday, February 15, 2016 

Distinctive properties of plaque-type dura mater graft-associated Creutzfeldt–Jakob disease in cell-protein misfolding cyclic amplification


2001 FDA CJD TSE Prion Singeltary Submission TSEAC
 

meanwhile, back at the ranch, the running of the mad cows, sheep, goats, deer, elk, are all out of the barn, and what do we care about, bathroom bills...sad/// 

MONDAY, MARCH 13, 2017

CHRONIC WASTING DISEASE CWD TSE PRION UDATE March 13, 2017


SATURDAY, JANUARY 14, 2017 

CHRONIC WASTING DISEASE CWD TSE PRION GLOBAL UPDATE JANUARY 14, 2017


THURSDAY, MARCH 30, 2017 

Norway CWD Skrantesjuke: VKM report supports the National Veterinary Institute perception management



WEDNESDAY, MARCH 15, 2017 

In vitro amplification of H-type atypical bovine spongiform encephalopathy by protein misfolding cyclic amplification

"When considering the atypical L-BSE and H-BSE diseases of cattle, they have been assessed in both non-human primate and transgenic mouse bioassays (with mice transgenic for human PRNP) and both model systems indicate that H-BSE and L-BSE may have increased zoonotic potential compare with C-BSE. The detection of all types of BSE is therefore of significant importance."


Wednesday, December 21, 2016

TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES 2016 ANNUAL REPORT ARS RESEARCH


 Thursday, October 22, 2015

Former Ag Secretary Ann Veneman talks women in agriculture and we talk mad cow disease USDA and what really happened


Thursday, December 08, 2016

USDA APHIS National Scrapie Eradication Program October 2016 Monthly Report Fiscal Year 2017 atypical NOR-98 Scrapie


Title: Transmission of scrapie prions to primate after an extended silent incubation period) 

*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.

 *** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.

 *** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.


SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016

Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online





Terry S. Singeltary Sr. 



 

Posted by at

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)