Highly Pathogenic Avian Influenza (H5N1) Virus in Feathers.

H5N1 highly pathogenic avian influenza (HPAI) virus causes high mortality of infected birds, with infection in multiple organs, including in feathers. Feathers have been proposed as samples for diagnosis of HPAI infection in birds, and this study is part of a broader investigation validating the use of feathers for diagnostic purposes. To understand and characterize the morphological basis for feather infection, sections from 7 different skin tracts of ducks and chickens infected with 3 different clades of H5N1 HPAI virus from Indonesia and Vietnam were examined histologically. Results showed that in ducks, lesions and viral antigen were mainly detected in the epidermis of feathers and follicles, whereas in chickens, they were mostly found in the dermis of these structures. Abundant viral antigen was found in nearly all the feathers examined from chickens, and there was no apparent difference between virus isolates or skin tracts in the proportion of feathers that were antigen positive. By immunohistochemistry, the majority of feathers from most skin tracts from ducks infected with a Vietnamese H5N1 HPAI virus contained abundant levels of viral antigen, while few feathers were antigen positive from ducks infected with 2 Indonesian viruses. These results support and inform the use of feathers for diagnostic detection of H5N1 HPAI virus in birds.

Outcome of challenging HIV case consultations provided via teleconference by the Clinician Consultation Center to the Federal Bureau of Prisons.

OBJECTIVES: To describe the collaboration and prospective outcome of challenging human immunodeficiency virus (HIV) cases presented by Board of Prisons (BOP) pharmacists in consultation with Clinician Consultation Center (CCC) clinical pharmacists and physicians to improve correctional patient care. SETTING: Federal correctional facilities. PRACTICE DESCRIPTION: Pharmacists improve care of incarcerated persons infected with HIV. PRACTICE INNOVATION: Pharmacists evaluate, implement, and provide successful oversight of HIV/hepatitis C virus (HCV) care. EVALUATION: Retrospective review of the clinical outcomes of HIV and HCV coinfected cases implemented by BOP pharmacists following CCC clinical consultations from 2010 through 2012. RESULTS: Most cases focused on selecting optimal antiretroviral therapy (ART) regimens in patients experiencing treatment failure by interpreting resistance tests, limiting ART toxicity, identifying adherence strategies, and managing HIV/HCV coinfection. In 32 of the 34 cases presented, 87.5% (28/32) of CCC recommendations were implemented, resulting in 89% of those patients (25/28) achieving optimal virologic or clinical outcome. Complete virologic suppression occurred in 64% (18/28), and significant viral load reductions in 25% (7/28) of the cases. No changes occurred in 2 patients, and data were not available in 2 others lost to follow-up. BOP participation has increased since its inception from 6 to 12-15 pharmacists per call. Discussions also included updates in antiretroviral guidelines, screening and management of patients coinfected with HIV and HCV, and implications for BOP guidelines. CONCLUSION: BOP clinical consultant pharmacists can successfully implement CCC recommendations to achieve desired clinical outcomes. Consultations and educational efforts from CCC experts assist BOP pharmacists in ensuring excellence in management of complex HIV/HCV issues and medication regimens to achieve desired outcomes. CCC collaboration and BOP pharmacist involvement have improved patient care. Using a team approach to include BOP clinical pharmacists and obtaining expert opinion in management of other chronic illnesses may be a model that can be considered to improve correctional care.

Federal Bureau of Prisons clinical pharmacy program improves patient A1C.

OBJECTIVE: The Federal Bureau of Prisons (BOP) currently has over 13,000 patients with diabetes and has placed an emphasis on preventing and delaying the onset or progression of diabetes-related complications. In an ongoing effort to improve patient outcomes, BOP has implemented a nationwide, dynamic system of pharmacist-delivered patient care services via pharmacist clinicians working under the auspices of a physician-pharmacist collaborative practice agreement (CPA). SETTING: The BOP Clinical Pharmacy Workgroup targets improved patient outcomes via oversight and support of institution pharmacist clinicians and physicians in establishing and maintaining physician-pharmacist CPAs. A primary emphasis is diabetes and the pharmacist-run clinic clinical outcomes data are presented. PRACTICE INNOVATION: Seventy (nearly one-half) of eligible BOP pharmacists at 37 institutions offer pharmacist-delivered patient care services via an approved CPA. In total, BOP has 111 active physician-pharmacist CPAs. MAIN OUTCOME MEASURES: Pharmacist-run diabetes clinic outcomes from 5 institutions have been reported to date. A total of 126 patients were enrolled. Patient's hemoglobin A1C, blood pressure, and LDL cholesterol level are measured before (i.e., when accepted in the diabetes clinic) and after pharmacist-delivered care has been provided. The pharmacist-run diabetes clinics reported an average baseline A1C of 10.6% and produced an average outcome decrease in A1C of 2.3% from baseline. RESULTS: Specific pharmacist clinic interventions found to have the greatest impact are: 1) timely medication adjustment when indicated to help patients meet outcome goals; and 2) timely follow-up after a change in therapy is made (often within 1-2 weeks) with continued medication adjustment when indicated until outcome goal is achieved. CONCLUSION: BOP pharmacists have become respected and trusted clinicians within the team medicine model. As demonstrated by the pharmacist-run diabetes clinic outcomes, pharmacist clinicians are a valued link to the improvement of patient outcomes in BOP.

Increased sensitivity to platinum drugs of cancer cells with acquired resistance to trabectedin.

BACKGROUND: In order to investigate the mechanisms of acquired resistance to trabectedin, trabectedin-resistant human myxoid liposarcoma (402-91/T) and ovarian carcinoma (A2780/T) cell lines were derived and characterised in vitro and in vivo. METHODS: Resistant cell lines were obtained by repeated exposures to trabectedin. Characterisation was performed by evaluating drug sensitivity, cell cycle perturbations, DNA damage and DNA repair protein expression. In vivo experiments were performed on A2780 and A2780/T xenografts. RESULTS: 402-91/T and A2780/T cells were six-fold resistant to trabectedin compared with parental cells. Resistant cells were found to be hypersensitive to UV light and did not express specific proteins involved in the nucleotide excision repair (NER) pathway: XPF and ERCC1 in 402-91/T and XPG in A2780/T. NER deficiency in trabectedin-resistant cells was associated with the absence of a G2/M arrest induced by trabectedin and with enhanced sensitivity (two-fold) to platinum drugs. In A2780/T, this collateral sensitivity, confirmed in vivo, was associated with an increased formation of DNA interstrand crosslinks. CONCLUSIONS: Our finding that resistance to trabectedin is associated with the loss of NER function, with a consequent increased sensitivity to platinum drugs, provides the rational for sequential use of these drugs in patients who have acquired resistance to trabectedin.

Federal Bureau of Prisons HIV consultant pharmacist monitoring and advisory program.

OBJECTIVE: To present outcomes resulting from the implementation of a pharmacist-run human immunodeficiency virus (HIV) medication management model. SETTING: Federal Bureau of Prisons (BOP) from December 2004 to December 2009. PRACTICE DESCRIPTION: The BOP instituted the National HIV Clinical Pharmacist Consultant (NHCPC) program in December 2004. NHCPCs monitor and provide guidance as to the appropriateness of antiretroviral therapy (ART) throughout the BOP. They also serve as readily accessible resources for all BOP providers, having the training and expertise necessary to affect positive patient outcomes. NHCPCs were provided intensive training through a Johns Hopkins University HIV/acquired immunodeficiency syndrome pharmacotherapy traineeship administered by the American Society of Consultant Pharmacists and have AAHIVE (HIV Expert) credentialing. PRACTICE INNOVATION: NHCPCs monitor HIV therapy and patient outcomes via BOP electronic medical records. MAIN OUTCOME MEASURES: The vision for this program encompasses an overall healthier BOP HIV patient population being treated in accordance with current Department of Health & Human Services guidelines. Specifically, all patients taking ART have the goals of (1) achieving undetectable viral loads (≥70%), (2) maintaining CD4 T-cell counts of 200 cells/mm3 or more (≥70%), and (3) taking at least 90% of prescribed doses. RESULTS: From April 2004 to December 2009, the overall percentage of BOP patients with undetectable viral loads increased from 32% to 66%. As of December 2009, 76% of patients receiving ART achieved CD4 counts of 200 cells/mm3 or greater and 73% were taking 90% or more of prescribed doses. CONCLUSION: The NHCPC program lends credence to the value of pharmacists in improving patient outcomes.

A diverse family of novel peptide toxins from an unusual cone snail, Conus californicus.

Diversity among Conus toxins mirrors the high species diversity in the Indo-Pacific region, and evolution of both is thought to stem from feeding-niche specialization derived from intra-generic competition. This study focuses on Conus californicus, a phylogenetic outlier endemic to the temperate northeast Pacific. Essentially free of congeneric competitors, it preys on a wider variety of organisms than any other cone snail. Using molecular cloning of cDNAs and mass spectrometry, we examined peptides isolated from venom ducts to elucidate the sequences and post-translational modifications of two eight-cysteine toxins (cal12a and cal12b of type 12 framework) that block voltage-gated Na(+) channels. Based on homology of leader sequence and mode of action, these toxins are related to the O-superfamily, but differ significantly from other members of that group. Six of the eight cysteine residues constitute the canonical framework of O-members, but two additional cysteine residues in the N-terminal region define an O+2 classification within the O-superfamily. Fifteen putative variants of Cal12.1 toxins have been identified by mRNAs that differ primarily in two short hypervariable regions and have been grouped into three subtypes (Cal12.1.1-3). This unique modular variation has not been described for other Conus toxins and suggests recombination as a diversity-generating mechanism. We propose that these toxin isoforms show specificity for similar molecular targets (Na(+) channels) in the many species preyed on by C. californicus and that individualistic utilization of specific toxin isoforms may involve control of gene expression.

Neuronal inclusions resembling Negri bodies in the thalamus of a red kangaroo (Macropus rufus).

Eosinophilic intracytoplasmic neuronal inclusions resembling Negri bodies, but not associated with lyssaviral infection, were detected in the ventrolateral thalamus of a young-adult, male red kangaroo (Macropus rufus). Similar neuronal inclusions, also with a regional distribution in the brain, have been reported as an incidental, possibly age-related finding in other animal species.

Actin-related protein 1 and cytoplasmic dynein-based motility - what's the connection?

The actin-related protein Arp1 works in conjunction with the microtubule-based motor cytoplasmic dynein to drive many types of intracellular motility. In vertebrate cells, Arp1 is present exclusively in the form of a 37-nm filament that constitutes the backbone of dynactin, a 1.2-MDa macromolecular complex containing nine other polypeptides. Dynactin has been proposed to function as the link between dynein and its cargo. Recent work indicates that the dynactin subunit p150(Glued) mediates the interaction of the dynactin molecule with dynein and microtubules, leaving the Arp1 filament as a possible cargo-binding domain. Mechanisms for binding of F-actin to membranes are discussed as models of the Arp1-membrane interaction.

Opposing motor activities are required for the organization of the mammalian mitotic spindle pole.

We use both in vitro and in vivo approaches to examine the roles of Eg5 (kinesin-related protein), cytoplasmic dynein, and dynactin in the organization of the microtubules and the localization of NuMA (Nu-clear protein that associates with the Mitotic Apparatus) at the polar ends of the mammalian mitotic spindle. Perturbation of the function of Eg5 through either immunodepletion from a cell free system for assembly of mitotic asters or antibody microinjection into cultured cells leads to organized astral microtubule arrays with expanded polar regions in which the minus ends of the microtubules emanate from a ring-like structure that contains NuMA. Conversely, perturbation of the function of cytoplasmic dynein or dynactin through either specific immunodepletition from the cell free system or expression of a dominant negative subunit of dynactin in cultured cells results in the complete lack of organization of microtubules and the failure to efficiently concentrate the NuMA protein despite its association with the microtubules. Simultaneous immunodepletion of these proteins from the cell free system for mitotic aster assembly indicates that the plus end-directed activity of Eg5 antagonizes the minus end-directed activity of cytoplasmic dynein and a minus end-directed activity associated with NuMA during the organization of the microtubules into a morphologic pole. Taken together, these results demonstrate that the unique organization of the minus ends of microtubules and the localization of NuMA at the polar ends of the mammalian mitotic spindle can be accomplished in a centrosome-independent manner by the opposing activities of plus end- and minus end-directed motors.

Molecular requirements for bi-directional movement of phagosomes along microtubules.

Microtubules facilitate the maturation of phagosomes by favoring their interactions with endocytic compartments. Here, we show that phagosomes move within cells along tracks of several microns centrifugally and centripetally in a pH- and microtubule-dependent manner. Phagosome movement was reconstituted in vitro and required energy, cytosol and membrane proteins of this organelle. The activity or presence of these phagosome proteins was regulated as the organelle matured, with "late" phagosomes moving threefold more frequently than "early" ones. The majority of moving phagosomes were minus-end directed; the remainder moved towards microtubule plus-ends and a small subset moved bi-directionally. Minus-end movement showed pharmacological characteristics expected for dyneins, was inhibited by immunodepletion of cytoplasmic dynein and could be restored by addition of cytoplasmic dynein. Plus-end movement displayed pharmacological properties of kinesin, was inhibited partially by immunodepletion of kinesin and fully by addition of an anti-kinesin IgG. Immunodepletion of dynactin, a dynein-activating complex, inhibited only minus-end directed motility. Evidence is provided for a dynactin-associated kinase required for dynein-mediated vesicle transport. Movement in both directions was inhibited by peptide fragments from kinectin (a putative kinesin membrane receptor), derived from the region to which a motility-blocking antibody binds. Polypeptide subunits from these microtubule-based motility factors were detected on phagosomes by immunoblotting or immunoelectron microscopy. This is the first study using a single in vitro system that describes the roles played by kinesin, kinectin, cytoplasmic dynein, and dynactin in the microtubule-mediated movement of a purified membrane organelle.

Analysis of dynactin subcomplexes reveals a novel actin-related protein associated with the arp1 minifilament pointed end.

The multisubunit protein, dynactin, is a critical component of the cytoplasmic dynein motor machinery. Dynactin contains two distinct structural domains: a projecting sidearm that interacts with dynein and an actin-like minifilament backbone that is thought to bind cargo. Here, we use biochemical, ultrastructural, and molecular cloning techniques to obtain a comprehensive picture of dynactin composition and structure. Treatment of purified dynactin with recombinant dynamitin yields two assemblies: the actin-related protein, Arp1, minifilament and the p150(Glued) sidearm. Both contain dynamitin. Treatment of dynactin with the chaotropic salt, potassium iodide, completely depolymerizes the Arp1 minifilament to reveal multiple protein complexes that contain the remaining dynactin subunits. The shoulder/sidearm complex contains p150(Glued), dynamitin, and p24 subunits and is ultrastructurally similar to dynactin's flexible projecting sidearm. The dynactin shoulder complex, which contains dynamitin and p24, is an elongated, flexible assembly that may link the shoulder/sidearm complex to the Arp1 minifilament. Pointed-end complex contains p62, p27, and p25 subunits, plus a novel actin-related protein, Arp11. p62, p27, and p25 contain predicted cargo-binding motifs, while the Arp11 sequence suggests a pointed-end capping activity. These isolated dynactin subdomains will be useful tools for further analysis of dynactin assembly and function.

Maternal IgM anti-D, borderline foetal Doppler middle cerebral artery velocities and absent neonatal haemolysis.

Anti-D was detected for the first time at 36 weeks gestation in a group A RhD-negative primigravida without prior sensitizing events or anti-D administration. Simultaneously, foetal ultrasound showed middle cerebral artery maximum velocity (MCA V(max)) at the 95th centile but no hydrops. Labour was induced at 37 weeks. Although neonatal anaemia was anticipated, the baby, who was group O RhD-positive, was born with a normal haemoglobin and negative direct antiglobulin test and antibody screen. Retrospectively, the maternal anti-D proved to be exclusively immunoglobulin M (IgM), which does not cross the placenta. Foetal Doppler MCA V(max) measurements can give false positive results especially late in the third trimester. Thus, antibody class, especially in first pregnancies without prior sensitizing events, and the timing of foetal Doppler MCA velocity measurements should be considered when evaluating the likelihood and severity of haemolytic disease of the foetus and newborn.

In vivo cartilage contact deformation in the healthy human tibiofemoral joint.

OBJECTIVES: In vivo cartilage contact deformation is instrumental for understanding human joint function and degeneration. This study measured the total deformation of contacting articular cartilage in the human tibiofemoral joint during in vivo weight-bearing flexion. METHODS: Eleven healthy knees were magnetic resonance (MR) scanned and imaged with a dual fluoroscopic system while the subject performed a weight-bearing single-leg lunge. The tibia, femur and associated articulating cartilage were constructed from the MR images and combined with the dual fluoroscopic images to determine in vivo cartilage contact deformation from full extension to 120 degrees of flexion. RESULTS: In both compartments, minimum peak compartmental contact deformation occurred at 30 degrees of flexion (24 +/- 6% medial, 17 +/- 7% lateral) and maximum peak compartmental deformation occurred at 120 degrees of flexion (30 +/- 13% medial, 30 +/- 10% lateral) during the weight-bearing flexion from full extension to 120 degrees. Average medial contact areas and peak contact deformations were significantly greater than lateral compartment values (P < 0.05). In addition, cartilage thickness in regions of contact was on average 1.4- and 1.1-times thicker than the average thickness of the tibial and femoral cartilage surfaces, respectively (P < 0.05). CONCLUSIONS: These data may provide base-line knowledge for investigating the effects of various knee injuries on joint contact biomechanics and the aetiology of cartilage degeneration.

Development of a TaqMan PCR assay for the detection of Trypanosoma evansi, the agent of surra.

A TaqMan PCR assay was developed for the detection of Trypanosoma evansi. The assay targets the internal transcribed spacer 1 (ITS-1) region of rRNA. The ITS-1 region of eleven strains of T. evansi from widely separated geographical regions were sequenced and alignments compared. Primers and probe for the test were designed from these sequence data. The assay was tested using blood from infected rats and was found to be sensitive, detecting less than one genomic equivalent of T. evansi. The assay has been tested against 10 different species of trypanosomes found in native animals in Australia and did not detect any of these trypanosome species. Time course experiments using rats infected with T. evansi were performed to compare the TaqMan assay with the Haematocrit centrifugation test (HCT) and the mouse inoculation (MI) assay. The assay was more sensitive than the HCT but not as sensitive as the MI. The TaqMan assay has the ability to rapidly detect T. evansi and determine the number of organisms present in a blood sample from an infected animal. This is the first time a TaqMan assay has been developed for the detection of T. evansi.

Towards an empirical model of performance enhancing supplement use: a pilot study among high performance UK athletes.

This paper addressed a gap in the literature of empirically derived models of performance enhancing supplement use by developing a demographic and psychosocially based model of athlete supplement use. Selected questions were used from a larger survey conducted by UK Sport into British athletes' experiences, knowledge, attitudes and opinions in relation to anti-doping activities. Forward conditional step wise logistic regression was employed on data from n=757 athletes to develop a model that discriminated supplement non-users from users. The model identified that British athletes most likely to use supplements were younger (under 23) males who were more likely to see doping as a problem in their sport and were more knowledgeable about testing procedures than their non-user counterparts. Post hoc analysis reinforced that non-users saw doping as less of a problem in their sport and were less knowledgeable about drug testing procedures relative to those using supplements. The pattern of results indicated gender-specific interventions on supplement use for young male athletes may yield significant benefits. The relationship between supplement use and perception of a doping problem suggested more work is needed to understand supplement use culture within sports. The relationship between knowledge of testing procedures and supplement use suggested further research is needed to see whether this is a positive or negative effect of detection-based doping deterrence activity.

Self-regulated polymerization of the actin-related protein Arp1.

The actin-related protein Arp1 (or centractin, actin RPV) is the major subunit of dynactin, a key component of the cytoplasmic dynein motor machinery [1] [2] [3]. Of the ubiquitously expressed members of the Arp superfamily, Arp1 is most similar to conventional actin [4] [5] [6] and, on the basis of conserved sequence features, is predicted to bind ATP and possibly polymerize. In vivo, all cytosolic Arp1 sediments at 20S [7] suggesting that it assembles into oligomers, most likely dynactin - a multiprotein complex known to contain eight or nine Arp1 monomers in a 37 nm filament [8]. The uniform length of Arp1 polymers suggests a novel assembly mechanism that may be governed by a 'ruler' activity. In dynactin, the Arp1 filament is bounded by actin-capping protein at one end and a heterotetrameric protein complex containing the p62 subunit (D.M. Eckley, S.R. Gill, J.B.B., J.E. Heuser, T.A.S., unpublished observations) at the other [8]. In the present study, we analyzed the behavior of highly purified, native Arp1. Arp1 was found to polymerize rapidly into short filaments that were similar, but not identical, in length to those in dynactin. With time, these filaments appeared to anneal to form longer assemblies but never attained the length of conventional actin filaments.

DNA-mediated cotransfer of excision repair capacity and drug resistance into chinese hamster ovary mutant cell line UV-135.

We have investigated DNA-mediated transfer of aminopterin resistance conferred by plasmid and UV resistance conferred by genomic DNA to the Chinese hamster ovary (CHO) cell line UV-135, a UV-sensitive mutant defective in nucleotide excision repair. Plasmid pSV2gpt-CaPO4 coprecipitates induced aminopterin resistance with equal efficiency in the 6-thioguanine-resistant, aminopterin-sensitive, repair-proficient parental line AA8-4(tg-1) and in UV-135(tg-2). Genetic and molecular evidence for genomic DNA-mediated transformation of UV-135(tg-2) cells with a putative excision repair gene were obtained by demonstrating that: (i) UV resistance transformation is dependent upon and specific for genomic DNA from excision repair-competent CHO cells: (ii) UV and drug coresistant colonies are bona fide transferants as verified by hybridization and Southern blotting analysis of pSV2gpt sequences in their genomic DNAs: (iii) confirmed transferants exhibit partial to near normal UV resistances for colony formation: and (iv) UVr transferants have near normal levels of excision repair capacity. The overall frequency of drug and UV resistance cotransformation was 8 X 10(8) per cell plated. This frequency was ca. 200- to 500-fold greater than that expected from coincident but independent UVr reversion and plasmid gene transfer events. DNA transfer techniques with this CHO system will be useful for further analysis of the essential structural DNA sequences, gene cloning, and expression of functional excision repair genes.

Targeting of tumor cells and DNA by a chlorambucil-spermidine conjugate.

Many tumor cells, including murine ADJ/PC6 plasmacytoma cells, possess an active energy dependent polyamine uptake system which selectively accumulates endogenous polyamines and structurally related compounds. We have attempted to target the cytotoxic drug chlorambucil to a tumor possessing this uptake system by conjugating it to the polyamine spermidine. Furthermore, since polyamines have a high affinity for DNA, the attachment of spermidine to chlorambucil should also facilitate its targeting to DNA. This was supported by the observation that the chlorambucil-spermidine conjugate was approximately 10,000-fold more active than chlorambucil at forming interstrand crosslinks with naked DNA. In vitro cytotoxicity and in vivo antitumor studies were carried out using the ADJ/PC6 plasmacytoma. In vitro, using [3H]thymidine incorporation to assess cell viability following a 1-h exposure to control and polyamine depleted ADJ/PC6 cells, chlorambucil-spermidine was 35- and 225-fold, respectively, more toxic than chlorambucil. The increased toxicity of the conjugate compared to chlorambucil was possibly due to enhanced DNA binding and/or facilitated uptake via the polyamine uptake system. The enhanced toxicity of the conjugate but not chlorambucil by prior polyamine depletion with difluoromethylornithine, together with the observation that the conjugate but not chlorambucil competitively inhibited spermidine uptake into tumor cells, supported the suggestion that the conjugate utilized the polyamine uptake system. In vivo following a single i.p. dose, the conjugate was 4-fold more potent than chlorambucil in its ability to inhibit ADJ/PC6 tumor growth in BALB/c mice. However, the therapeutic index was not increased. Our results support the hypothesis that polyamines linked to cytotoxics facilitate their entry into tumor cells possessing a polyamine uptake system and increase their selectivity to DNA. This may have therapeutic application in the delivery of cytotoxic agents linked to polyamines to certain tumors.

Atypical scrapie in Australia.

BACKGROUND: Since its initial detection in Norway in 1998, atypical scrapie ('atypical/Nor98 scrapie') has been reported in sheep in the majority of European countries (including in regions free of classical scrapie) and in the Falkland Islands, the USA, Canada, New Zealand and Australia. CASE SERIES: The diagnosis in Australia of atypical scrapie in four Merino and one Merino-cross sheep showing clinical signs of neurological disease was based on the detection of grey matter neuropil vacuolation (spongiform change) in the brain (particularly in the molecular layer of the cerebellar cortex) and associated abnormal prion protein (PrPSc ) deposition in both grey and white matter. Changes were minimal in the caudal brainstem, the predilection site for lesions of classical scrapie. CONCLUSION: The distinctive lesion profile of atypical scrapie in these five sheep highlights the diagnostic importance of routine histological evaluation of the cerebellum for evidence of neuropil vacuolation and associated PrPSc deposition in adult sheep with suspected neurological disease.