1,721,098 research outputs found
haploinsufficiency in a Holstein cattle with epilepsy
Full text linkIn this study, epilepsy with focal seizures progressing to generalized seizures was diagnosed in a 6-month-old Holstein heifer. The seizures were characterized by a brief pre-ictal phase with depression and vocalization. During the ictal phase eyelid spasms, tongue contractions, nodding and abundant salivation were observed, rapidly followed by a convulsive phase with bilateral tonic, clonic or tonic-clonic activity and loss of consciousness. Finally, during the postictal phase the heifer was obtunded and disorientated, unable to perceive obstacles and hypermetric, and pressed its head against objects. In the inter-seizure phase, the heifer was clinically normal. Neuropathology revealed axonal degeneration in the brainstem and diffuse astrocytic hypertrophic gliosis. Whole genome sequencing of the affected heifer identified a private heterozygous splice-site variant in DYRK1B (NM_001081515.1: c.-101-1G>A), most likely resulting in haploinsufficiency owing to loss-of-function. This represents a report of a DYRK1B-associated disease in cattle and adds DYRK1B to the candidate genes for epilepsy
Glomeruloid Microvascular Proliferation, Desmoplasia, and High Proliferative Index as Potential Indicators of High Grade Canine Choroid Plexus Tumors.
Full text linkChoroid plexus tumors (CPT) are intraventricular neoplasms accounting for 10% of all primary central nervous system tumors in dogs. They are frequently classified according to the human WHO classification into choroid plexus papilloma (CPP, grade I), atypical CPP (aCPP, grade II), and choroid plexus carcinoma (CPC, grade III). Histological features observed in canine CPT such as increased vascular density (IVD) and glomeruloid microvascular proliferation (GMVP) are not part of the WHO classification. This multi-centric study aimed to investigate tumor-associated vascular hyperplasia in dogs by determining the prevalence of GMVP and IVD in 52 canine CPT and their association with tumor grade. In addition, the expression of angiogenic factors was assessed by immunohistochemistry in 25 tumors to investigate the pathogenesis of tumor-associated vascular hyperplasia. Based on the classical histological hallmarks, this study of 52 CPT identified 22 (42%) CPP (grade I) and 30 of (58%) CPC (grade III). GMVP was more prevalent in CPC (13/30; 43%) than CPP (1/22; 4%), whereas IVD occurred to a similar extent in CPP and CPC. Desmoplasia was more common in CPC (19/30; 63%) than CPP (2/22; 9%), and similarly, the proliferative index (PI) of neoplastic epithelium was significantly higher in CPC (5.14%) than CPP (0.94%). The majority of CPT expressed platelet-derived growth factor (PDGF), PDGFRα, PDGFRβ, and vascular endothelial growth factor (VEGF) irrespective of tumor grade or tumor-associated vascular hyperplasia. These results suggest that tumor-associated GMVP, desmoplasia, and PI may serve as histological indicators of malignancy in CPT
Diffuse Leptomeningeal Oligodendrogliomatosis in a Cow.
No full textA 4.5-year-old cow showing neurological signs consistent with predictors of bovine spongiform encephalopathy (BSE) was investigated as a potential BSE-suspect case and proved to be negative. Macroscopic analysis revealed a tan neoplastic mass growing along the leptomeninges of the caudal brain and extending into the third (III) ventricle without significantly involving the neuroparenchyma. Pathological features (uniform round hyperchromatic neoplastic cells embedded in abundant myxoid matrix, microcysts, microvascular proliferation) and diffuse Olig2 expression were most consistent with diffuse high-grade leptomeningeal oligodendrogliomatosis. In line with former reports of extensive leptomeningeal involvement in bovine oligodendroglioma, this report suggests that bovine oligodendroglial tumors have a strong propensity to grow within the leptomeningeal space. In addition, it indicates that Olig2 is a useful marker to confirm glial lineage in formalin-fixed, paraffin-embedded bovine tissue
GWAS Hits for Bilateral Convergent Strabismus with Exophthalmos in Holstein Cattle Using Imputed Sequence Level Genotypes
Full text linkBilateral convergent strabismus with exophthalmos (BCSE) is a malformation of the eyes and is recognized as a mild but progressive disorder that affects cattle in the first two years of life. This most likely inherited disorder is rarely described in cattle resembling autosomal dominantly inherited forms of human progressive external ophthalmoplegia (PEO). In German Braunvieh cattle, two linked genome regions were found that could be responsible for the development and/or progression of BCSE. The goal of this study was to phenotypically characterize BCSE in Holstein cattle from Germany and Switzerland as well as to identify associated genome regions by GWAS. The clinicopathological phenotype of 52 BCSE-affected Holstein cattle was in accordance with the phenotype described in German Braunvieh cattle, but in addition, signs of degeneration and cellular infiltration in the eye muscles were found. By using imputed sequence level genotype data, three genome-wide significant GWAS hits were revealed on different chromosomes that were not detected by initial GWAS based on high density SNP array data highlighting the usefulness of this approach for mapping studies. The associated genome regions include the ABCC4 gene as well as markers adjacent to the NCOR2 and DNAJC3 genes all illustrating possible functional candidate genes. Our results challenge a monogenic mode of inheritance and indicate a more complex inheritance of BCSE in Holstein cattle. Furthermore, in comparison to previous results from German Braunvieh cattle, it illustrates an obvious genetic heterogeneity causing BSCE in cattle. Subsequent whole genome sequencing (WGS)-based analyses might elucidate pathogenic variants in the future
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Listeria Brainstem Encephalitis in Small Ruminants: Correlation of Magnetic Resonance Imaging and Histopathology.
No full textListeria Brainstem Encephalitis in Small Ruminants: Correlation of Magnetic Resonance Imaging and Histopathology
Christina Stahl1, Anna Oevermann2, Daniela Gorgas1
1Clinical Radiology, Department of Clinical Veterinary Medicine, Vetsuisse-Faculty, University of Bern, Switzerland
2Neurocenter, Department of Clinical Research and Veterinary Public Health, Vetsuisse-Faculty, University of Bern, Switzerland
Abstract
Brainstem encephalitis is an intriguing form of Listeria monocytogenes central nervous system (CNS) infection in humans and ruminants and has a high fatality rate. However, intra vitam diagnosis remains difficult in both species (1, 2). We performed MRI of affected small ruminants, in which Listeria brainstem encephalitis is a common CNS disease, and correlated MRI features with histopathology in order to define MRI criteria for the diagnosis of listeria brainstem encephalitis.
Fifteen small ruminants (nine sheep, six goats) with listeriosis underwent MRI examination of the brain using a 0.3 T system (five animals) and 1.0 T system (ten animals) including T2w, FLAIR and T1w sequences pre and post Gadolinium administration. Listeria brainstem encephalitis was confirmed by histopathology, and histopathological changes were correlated to MRI features.
On MRI, lesions were best visualized in T2-weighted sequences. In all animals they were characterized by asymmetric increased signal intensity in the rhombencephalon in T2w and FLAIR sequences. The lesions showed a variable pattern and distribution, ranging from patchy with ill defined borders to diffusely affecting the entire cross-sectional area of the brainstem. Few animals had lesions in the diencephalon (three animals), whilst histopathologically detectable lesions commonly extended to the diencephalon and involved cranial nerve roots (twelve animals). The lesions were iso- to mildly hypointens in T1w sequence. Mild to moderate patchy or ring-like contrast uptake was observed in the rhombencephalon of five animals (one sheep, four goats), which showed vascular damage and perivascular fibrin accumulation on light microscopy.
In the brainstem, the asymmetric T2-hyperintense lesions observed by MRI correlated well with the inflammatory infiltrates observed in histopathology (3). However, lesions in the diencephalon, cranial nerves and meninges of rostral brain areas were rarely detected by MRI, indicating that MRI underestimates involvement of the rostral brain and brain associated structures. Contrary to reported human cases of neurolisteriosis (4), contrast uptake was an inconsistent finding occurring in the rhombencephalon of only five animals.
References
1. Armstrong RW, Fung PC. Brainstem encephalitis (rhombencephalitis) due to Listeria monocytogenes: case report and review. Clin Infect Dis. 1993;16(5):689-702. Review.
2. Oevermann A, Botteron C, Seuberlich T, Nicolier A, Friess M, Doherr MG, et al. Neuropathological survey of fallen stock: active surveillance reveals high prevalence of encephalitic listeriosis in small ruminants. Vet Microbiol. 2008 Aug 25;130(3-4):320-9.
3. Antal EA, Loberg EM, Dietrichs E, Maehlen J. Neuropathological findings in 9 cases of listeria monocytogenes brain stem encephalitis. Brain Pathol. 2005;15(3):187-91.
4. Reynaud L, Graf M, Gentile I, Cerini R, Ciampi R, Noce S, et al. A rare case of brainstem encephalitis by Listeria monocytogenes with isolated mesencephalic localization. Case report and review. Diagn Microbiol Infect Dis. 2007;58(1):121-3
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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