Emergence of Classical BSE Strain Properties during Serial Passages of H-BSE in Wild-Type Mice

BACKGROUND: Two distinct forms of atypical spongiform encephalopathies (H-BSE and L-BSE) have recently been identified in cattle. Transmission studies in several wild-type or transgenic mouse models showed that these forms were associated with two distinct major strains of infectious agents, which also differed from the unique strain that had been isolated from cases of classical BSE during the food-borne epizootic disease. METHODOLOGY/PRINCIPAL FINDINGS: H-BSE was monitored during three serial passages in C57BL/6 mice. On second passage, most of the inoculated mice showed molecular features of the abnormal prion protein (PrP(d)) and brain lesions similar to those observed at first passage, but clearly distinct from those of classical BSE in this mouse model. These features were similarly maintained during a third passage. However, on second passage, some of the mice exhibited distinctly different molecular and lesion characteristics, reminiscent of classical BSE in C57Bl/6 mice. These similarities were confirmed on third passage from such mice, for which the same survival time was also observed as with classical BSE adapted to C57Bl/6 mice. Lymphotropism was rarely detected in mice with H-BSE features. In contrast, PrP(d) was detectable, on third passage, in the spleens of most mice exhibiting classical BSE features, the pattern being indistinguishable from that found in C57Bl/6 mice infected with classical BSE. CONCLUSION/SIGNIFICANCE: Our data demonstrate the emergence of a prion strain with features similar to classical BSE during serial passages of H-BSE in wild-type mice. Such findings might help to explain the origin of the classical BSE epizootic disease, which could have originated from a putatively sporadic form of BSE

The 3D OrbiSIMS—label-free metabolic imaging with subcellular lateral resolution and high mass-resolving power

We report the development of a 3D OrbiSIMS instrument for label-free biomedical imaging. It combines the high spatial resolution of secondary ion mass spectrometry (SIMS; under 200 nm for inorganic species and under 2 μm for biomolecules) with the high mass-resolving power of an Orbitrap (>240,000 at m/z 200). This allows exogenous and endogenous metabolites to be visualized in 3D with subcellular resolution. We imaged the distribution of neurotransmitters—gamma-aminobutyric acid, dopamine and serotonin—with high spectroscopic confidence in the mouse hippocampus. We also putatively annotated and mapped the subcellular localization of 29 sulfoglycosphingolipids and 45 glycerophospholipids, and we confirmed lipid identities with tandem mass spectrometry. We demonstrated single-cell metabolomic profiling using rat alveolar macrophage cells incubated with different concentrations of the drug amiodarone, and we observed that the upregulation of phospholipid species and cholesterol is correlated with the accumulation of amiodarone

Gestion de l’infection sur materiel d’osteosynthese dans la chirurgie du rachis lombaire : Notre experience au Togo.

Objectif : Rapporter notre expérience de management d’infections post-ostéosynthèses de rachis lombaire à partir deux observations cliniques.Méthodologie : Il s’agit d’une analyse de nos deux premiers cas d’infections rachidiennes post opératoires après deux années de pratique neurochirurgicale post-résidanat en clientèle privée. Nous insistons sur les modes de révélation, la prise en charge et le résultat.Cas cliniques : Sur une série de dix-huit (18) rachis dorso-lombaires ostéosynthésés en deux ans, nous avons enregistré deux (02) cas d’infections postopératoires. Les germes isolés étaient Eschérichia coli multirésistant et Proteus vulgaris. Les deux patientes avaient respectivement 61 et 44 ans et nous réalisons pour chacune une laminectomie, une ostéosynthèse avec implant en titane et une greffe osseuse pour des lésions dégénératives. Elles avaient toutes deux eu des infiltrations lombaires sans amélioration de leur symptomatologie. L’infection du site opératoire était descellée respectivement à J4 et J30. Les deux patientes étaient apyrétiques. Pour la 1ère, le matériel d’ostéosynthèse a été laissé en place. Pour la 2ème, la persistance du syndrome infectieux biologique et le suintement chronique du site opératoire ont motivé l’ablation du matériel à 3 mois. Pour cette dernière la guérison clinique et biologique a été obtenue au bout de 6 mois L’évolution ultérieure est bonne chez les deux patients à un recul respectif de 28 mois et 15 mois.Conclusion : En cas d’infection profonde descellée précocement, une attitude conservatrice de l’implant est justifiée pour les rachis dégénératifs ostéosynthésés. A défaut, on tiendra compte notamment de la CRP et du risque d’instabilité rachidienne. Mots clés : Infection, Matériel d’ostéosynthèse, Rachis lombaire, Togo. English Abstract Management of infections in lumbar spine surgery with instrumentation: Our experience at Togo.  Objective: Report our experience of infections management after lumbar spine synthesis about two recent cases.Methods: It is an analysis of our first post operative’s lumbar spine infections during two years of neurosurgical practice in private office when we came back to Togo after our residency. We insist on the modalities of detection, the caring and the results.Case report: Among the 18th synthesis on thoracic and lumbar spine during the twice years, we detect two cases of post operative’s infections. The agents responsible were Escherichia coli multi resistant and Proteus vulgaris. The two female patients were respectively 61 and 44 years old and we perform for each patient a laminectomy, synthesis with titanium implant and bone graft for degenerative diseases. Previously the patients had had lumbar infiltration of corticosteroid without releasing their pain and disabilities. The infection processes were detected the 4th and 30th days postoperative. There was no fever. For the first patient, synthesis implant stays in place. For the second patient, the implant was retired through a thirds’ surgery after 3 months, due to persistence of biologic sign of infection and sweating from the operative site. The clinical and biological healing for this patient, were obtained 6 months after the first surgery. Till today, the both patients had none symptoms at respectively 28- and 15-months outcome.Conclusion: When post-operative infection is detected earlier, a conservative attitude of the implant is justified for degenerative spine instrumented. Otherwise, the CRP and the risk of spinal instability will be taken into account. Keys words: Infection, Lumbar spine, Synthesis Implant, Tog