The adequacy of a histopathological diagnosis of bovine spongiform encephalopathy (BSE) based exclusively on observations of neuroparenchymal vacuolation in three specific neuroanatomic nuclei was tested by using a standard coronal section of medulla oblongata cut at the obex. The agreement between the observations and the definitive histopathological diagnosis was assessed in each of 684 bovine brains - 563 confirmed cases of BSE, 20 with changes which did not diagnose BSE conclusively and 101 in which the lesions of BSE were not detected. When the assessment was confined to the solitary tract nucleus and the spinal tract nucleus of the trigeminal nerve a positive result was obtained in 99.6 per cent of confirmed cases of BSE and only 1 per cent of brains in which lesions of BSE were not detected gave a false positive result. Thus an initial examination of the single section, together with an examination of representative areas of the rest of the brain when no unequivocal lesion was found, provided a satisfactory method for the routine diagnosis of BSE.
The vasculature undergoes changes in diameter, permeability and blood flow in response to specific stimuli. The dynamics and interdependence of these responses in different vessels are largely unknown. Here we report a non-invasive technique to study dynamic events in different vessel categories by multi-photon microscopy and an image analysis tool, RVDM (relative velocity, direction, and morphology) allowing the identification of vessel categories by their red blood cell (RBC) parameters. Moreover, Claudin5 promoter-driven green fluorescent protein (GFP) expression is used to distinguish capillary subtypes. Intradermal injection of vascular endothelial growth factor A (VEGFA) is shown to induce leakage of circulating dextran, with vessel-type-dependent kinetics, from capillaries and venules devoid of GFP expression. VEGFA-induced leakage in capillaries coincides with vessel dilation and reduced flow velocity. Thus, intravital imaging of non-invasive stimulation combined with RVDM analysis allows for recording and quantification of very rapid events in the vasculature.
There is considerable variability in early switch from parenteral to oral antibiotic criteria for patients with community-acquired pneumonia. Early switch and early discharge strategies may significantly and safely reduce the mean LOS when the recommended LOS is shorter than the actual LOS.
Facioscapulohumeral muscular dystrophy (FS HD) is the third most common muscular dystrophy after the dystrophinopathies and myotonic dystrophy and is associated with a typical pattern of muscle weakness. Most patients with FSHD carry a large deletion in the polymorphic D4Z4 macrosatellite repeat array at 4q35 and present with 1-10 repeats whereas non-affected individuals possess 11-150 repeats. An almost identical repeat array is present at 10q26 and the high sequence identity between these two arrays can cause difficulties in molecular diagnosis. Each 3.3-kb D4Z4 unit contains a DUX4 (double homeobox 4) gene that, among others, is activated upon contraction of the 4q35 repeat array due to the induction of chromatin remodelling of the 4qter region. A number of 4q subtelomeric sequence variants are now recognised, although FSHD only occurs in association with three 'permissive' haplotypes, each of which is associated with a polyadenylation signal located immediately distal of the last D4Z4 unit. The resulting poly-A tail appears to stabilise DUX4 mRNAs transcribed from this most distal D4Z4 unit in FSHD muscle cells. Synthesis of both the DUX4 transcripts and protein in FSHD muscle cells induces significant cell toxicity. DUX4 is a transcription factor that may target several genes which results in a deregulation cascade which inhibits myogenesis, sensitises cells to oxidative stress and induces muscle atrophy, thus recapitulating many of the key molecular features of FSHD.
Neurofibromatosis type-1 (NF1) is associated with the growth of benign and malignant tumors. Approximately 15% of NF1 patients develop malignant peripheral nerve sheath tumors (MPNSTs), underlining the need to identify specific diagnostic/prognostic biomarkers associated with MPNST development. The Affymetrix Genome-Wide Human single-nucleotide polymorphism (SNP) Array 6.0 was used to perform SNP genotyping and copy number alteration (CNA), loss-of-heterozygosity (LOH), and copy number neutral-LOH (CNN-LOH) analyses of DNA isolated from 15 MPNSTs, five benign plexiform neurofibromas (PNFs), and patient-matched lymphocyte DNAs. MPNSTs exhibited high-level CNN-LOH, with recurrent changes occurring in MPNSTs but not PNFs. CNN-LOH was evident in MPNSTs but occurred less frequently than genomic deletions. CNAs involving the ITGB8, PDGFA, Ras-related C3 botulinum toxin substrate 1 (RAC1) (7p21-p22), PDGFRL (8p22-p21.3), and matrix metallopeptidase 12 (MMP12) (11q22.3) genes were specific to MPNSTs. Pathway analysis revealed the MPNST-specific amplification of seven Rho-GTPase pathway genes and several cytoskeletal remodeling/cell adhesion genes. In knockdown experiments employing short-hairpin RAC1, ROCK2, PTK2, and LIMK1 RNAs to transfect both control and MPNST-derived cell lines, cell adhesion was significantly increased in the MPNST cell lines, whereas wound healing, cell migration, and invasiveness were reduced, consistent with a role for these Rho-GTPase pathway genes in MPNST development and metastasis. These results suggest new targets for therapeutic intervention in relation to MPNSTs.
SUMMARYThe occurrence ofMycobacterium bovis infection in cattle herds during the period 1966-92 in two geographically related areas in South-West England is compared. In one area comprising 104 km2 all badgers were systematically destroyed from 1975-81, after which recolonization was allowed; in the other, comprising 116 kM2, small scale, statutory badger removal operations were undertaken from 1975 onwards where specific herds were detected with M. bovis infection. In the area with total clearance, no further incidents with M. bovis isolation occurred from 1982-92. Survival analysis and proportional hazards regression indicated that the risk of herds being identified with infection was less once badgers had been cleared from their neighbourhood, whereas it was greater in herds with 50 or more animals, and once cattle in a herd had responded positively to the tuberculin skin test, even though infection with M. bovis was not confirmed subsequently. The study provides further evidence that badgers represent an important reservoir of M. bovis infection for cattle and that badger control is effective in reducing incidents of cattle infection with M. bovis if action is thorough and recolonization is prevented.
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