Molecular, Biochemical and Genetic Characteristics of BSE in Canada

The epidemiology and possibly the etiology of bovine spongiform encephalopathy (BSE) have recently been recognized to be heterogeneous. In particular, three types [classical (C) and two atypical (H, L)] have been identified, largely on the basis of characteristics of the proteinase K (PK)-resistant core of the misfolded prion protein associated with the disease (PrPres). The present study was conducted to characterize the 17 Canadian BSE cases which occurred prior to November 2009 based on the molecular and biochemical properties of their PrPres, including immunoreactivity, molecular weight, glycoform profile and relative PK sensitivity. Two cases exhibited molecular weight and glycoform profiles similar to those of previously reported atypical cases, one corresponding to H-type BSE (case 6) and the other to L-type BSE (case 11). All other cases were classified as C-type. PK digestion under mild and stringent conditions revealed a reduced protease resistance in both of these cases compared to the C-type cases. With Western immunoblotting, N-terminal-specific antibodies bound to PrPres from case 6 but not to that from case 11 or C-type cases. C-terminal-specific antibodies revealed a shift in the glycoform profile and detected a fourth protein fragment in case 6, indicative of two PrPres subpopulations in H-type BSE. No mutations suggesting a genetic etiology were found in any of the 17 animals by sequencing the full PrP-coding sequence in exon 3 of the PRNP gene. Thus, each of the three known BSE types have been confirmed in Canadian cattle and show molecular characteristics highly similar to those of classical and atypical BSE cases described from Europe, Japan and the USA. The occurrence of atypical cases of BSE in countries such as Canada with low BSE prevalence and transmission risk argues for the occurrence of sporadic forms of BSE worldwide

Prion protein-specific antibodies that detect multiple TSE agents with high sensitivity

This paper describes the generation, characterisation and potential applications of a panel of novel anti-prion protein monoclonal antibodies (mAbs). The mAbs were generated by immunising PRNP null mice, using a variety of regimes, with a truncated form of recombinant ovine prion protein spanning residues 94–233. Epitopes of specific antibodies were mapped using solid-phase Pepscan analysis and clustered to four distinct regions within the PrP molecule. We have demonstrated the utility of these antibodies by use of Western blotting and immunohistochemistry in tissues from a range of different species affected by transmissible spongiform encephalopathy (TSE). In comparative tests against extensively-used and widely-published, commercially available antibodies, similar or improved results can be obtained using these new mAbs, specifically in terms of sensitivity of detection. Since many of these antibodies recognise native PrPC, they could also be applied to a broad range of immunoassays such as flow cytometry, DELFIA analysis or immunoprecipitation. We are using these reagents to increase our understanding of TSE pathogenesis and for use in potential diagnostic screening assays

A new Concept for Integrated Guidance and Drive of Railway Running Gears

Actively applying a relative torque which interacts with the relative rotation of the wheels of an axle provides both the increase of running stability at high velocities and steering of the vehicle with decrease of friction power and thus wear in curves. For vehicles with single-wheel drive the relative torque control can be combined with the traction control by an integrated approach including the estimation of feedback signal, which cannot be measured directly. These capabilities are presented by simulation and experimental results, performed with a two-axle vehicle on a 1:5 scaled roller rig

A Mechatronic Approach for Active Influence on Railway Vehicle Running Behaviour

A mechatronic wheelset concept is presented, by which relative torque interacting with the relative rotation of the wheels is actively applied to both wheels of an axle. This method provides both the increase of running stability at high velocities and steering of the vehicle with decrease of friction power and thus wear in curves. Therefore, the classical design conflict between running stability and good curve negotiation can be solved. These capabilities are presented by simulation and experimental reuslts, performed with a two-axle vehicle on a 1:5 scaled roller rig

Simulation of an Integrated Mechatronic Train

This paper describes the modelling of an integrated mechatronic railway vehicle which results from the Mechatronic Train project. The vehicle model includes the use of some advanced control functions such as actively controlled independently rotating wheels and secondary suspension. Therefore an integrated approach for suspension, traction and steering control is needed