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Purpose: Field-to-susceptibility inversion in quantitative susceptibility mapping (QSM) is ill-posed and needs numerical stabilization through either regularization or oversampling by acquiring data at three or more object orientations. Calculation Of Susceptibility through Multiple Orientations Sampling (COSMOS) is an established oversampling approach and regarded as QSM gold standard. It achieves a well-conditioned inverse problem, requiring rotations by 0°, 60° and 120° in the yz-plane. However, this is impractical in vivo, where head rotations are typically restricted to a range of ±25°. Non-ideal sampling degrades the conditioning with residual streaking artifacts whose mitigation needs further regularization. Moreover, susceptibility anisotropy in white matter is not considered in the COSMOS model, which may introduce additional bias. The current work presents a thorough investigation of these effects in primate brain., Methods: Gradient-recalled echo (GRE) data of an entire fixed chimpanzee brain were acquired at 7 T (350 μm resolution, 10 orientations) including ideal COSMOS sampling and realistic rotations in vivo. Comparisons of the results included ideal COSMOS, in-vivo feasible acquisitions with 3-8 orientations and single-orientation iLSQR QSM., Results: In-vivo feasible and optimal COSMOS yielded high-quality susceptibility maps with increased SNR resulting from averaging multiple acquisitions. COSMOS reconstructions from non-ideal rotations about a single axis required additional L2-regularization to mitigate residual streaking artifacts., Conclusion: In view of unconsidered anisotropy effects, added complexity of the reconstruction, and the general challenge of multi-orientation acquisitions, advantages of sub-optimal COSMOS schemes over regularized single-orientation QSM appear limited in in-vivo settings., Competing Interests: Declaration of competing interest The authors declare no competing interest., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Halicephalobus gingivalis is a nematode with zoonotic potential which can cause fatal opportunistic infections in various mammals. The parasite has never been diagnosed in Sweden, in any species, prior to the presented case., Case Presentation: An imported 21-year-old Icelandic mare developed severe neurological signs. The horse was eventually euthanized and submitted for post-mortem examination where severe lesions in the kidneys were noted. Histopathology revealed the presence of H. gingivalis in both kidneys and the brain. Phylogenetic analysis of the parasite determined it to belong to Lineage 1., Conclusions: With the occurrence of H. gingivalis in Sweden, the disease should be added to the list of differential diagnoses in cases with acute onset of neurological disease in both horses and other mammals including humans., (© 2023. The Author(s).)

'Staggering disease' is a neurological disease entity considered a threat to European domestic cats (Felis catus) for almost five decades. However, its aetiology has remained obscure. Rustrela virus (RusV), a relative of rubella virus, has recently been shown to be associated with encephalitis in a broad range of mammalian hosts. Here, we report the detection of RusV RNA and antigen by metagenomic sequencing, RT-qPCR, in-situ hybridization and immunohistochemistry in brain tissues of 27 out of 29 cats with non-suppurative meningoencephalomyelitis and clinical signs compatible with'staggering disease' from Sweden, Austria, and Germany, but not in non-affected control cats. Screening of possible reservoir hosts in Sweden revealed RusV infection in wood mice (Apodemus sylvaticus). Our work indicates that RusV is the long-sought cause of feline 'staggering disease'. Given its reported broad host spectrum and considerable geographic range, RusV may be the aetiological agent of neuropathologies in further mammals, possibly even including humans., (© 2023. The Author(s).)

Severe cardiomegaly with an atrial septal defect was discovered during necropsy of a subadult White-tailed Eagle (Haliaeetus albicilla) found dead in the wild. A thin membrane composed of fibromuscular tissue separated the left atrium into two chambers, most consistent with that described for cor triatriatum sinister (CTS) in other species. Seventeen months later, necropsy of an adult White-tailed Eagle again revealed CTS. This lesion has not been reported previously in raptors., (© Wildlife Disease Association 2021.)

Inflammatory bowel disease (IBD) in horses is an idiopathic disorder, encompassing different types of chronic intestinal inflammation. The pathogenesis of the disease remains to be established, but it has been suggested that an imbalance between regulatory T cells (Tregs) and T helper 17 (Th17)-associated cytokines and altered toll-like receptor 4 (TLR4) expression is associated with intestinal inflammation in other species. The aim of the present study was to quantify Tregs in rectal biopsies from horses affected with IBD by immunohistochemistry and to evaluate expression of genes encoding interleukin (IL)-12p40, IL-17A, IL-23p19 and TLR4 by real-time quantitative PCR. Rectal biopsies from 11 healthy horses and 11 horses with clinical signs of IBD, showing inflammation classified as chronic simple proctitis (CSP) or chronic active simple proctitis (CASP), were evaluated. Expression of IL-17A mRNA was greater in horses affected with CASP compared with horses with CSP or healthy horses. In contrast, expression of IL-12p40 was lower in horses with CSP compared with horses with CASP or healthy horses. TLR4 expression was greater in horses with CASP compared with healthy horses. A positive correlation was seen between the numbers of Tregs and expression of IL-17A and IL-23p19. An association was demonstrated between the histopathological pattern of inflammation, cytokine profile and number of infiltrating Tregs. The research findings suggest that Th17 cells are involved in active IBD, possibly through recruitment of neutrophils via IL-17A, in combination with inadequate suppression of the inflammatory response by Tregs., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

There is accumulating evidence for the involvement of pro-inflammatory cytokines associated with a T helper 17 response in intestinal disorders such as inflammatory bowel disease (IBD) in humans. The involvement of interleukin (IL)-17 or IL-23 in equine IBD has not been studied and most gene expression studies in the equine intestine have been limited to the use of a single non-validated reference gene. In this study, expression of the reference gene candidates β2 microglobulin (β2M), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), histone H2A type 1, hypoxanthine-guanine phosphoribosyltransferase (HPRT), 60S ribosomal protein L32 (RPL32), succinate dehydrogenase complex subunit A (SDHA) and transferrin receptor 1 protein coding (TFRC)in the equine intestine was evaluated by quantitative PCR. Three to four reference genes were adequate for normalisation of gene expression in the healthy duodenum, mid-jejunum, colon and rectum, although each segment required a unique combination of reference genes. No combination of the evaluated genes was optimal for the caecum and ileum. Another combination of reference genes (GAPDH, HPRT, RPL32 and SDHA) was optimal for normalisation of rectal samples from healthy and IBD-affected horses, indicating that reference genes should be re-evaluated if material from diseased specimens is analysed. Basal expression of IL-12p40, IL-17A and IL-23p19 was detected in each segment, which will enable gene expression studies of these cytokines by relative quantification., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The expression of tlr4, md2 and cd14 was studied in equine blood leukocytes and in intestinal samples using real time PCR. The stability of three commonly used reference genes, glyceraldehyde-3P-dehydrogenase (GAPDH), hypoxantine ribosyltransferase (HPRT) and succinate dehydrogenase complex subunit A (SDHA), was evaluated using qbase(PLUS). The equine peripheral blood mononuclear cells (eqPBMC) examined were either stimulated in vitro with Phorbol 12-myristate 13-acetate (PMA) and ionomycin or with the CpG oligodeoxynuclotide 2216 (CpG-ODN 2216) or obtained from horses before, during and after infusion of endotoxin. Intestinal tissue from healthy horses was sampled at ileum, right dorsal colon and rectum. Ranking of the three reference genes used for normalisation identified the combination HPRT/SDHA as most suitable both when determined ex vivo in leukocytes obtained from experimentally induced endotoxaemia and in eqPBMC activated in vitro while HPRT/GAPDH were most appropriate for the intestinal samples. The relative amounts of mRNA for TLR4 and MD-2 increased threefold during in vitro activation of the cells with CpG-ODN 2216 but was decreased in cultures stimulated with PMA/ionomycin. A transient elevation in the transcription of tlr4 and md2 was also evident for equine blood leukocytes following endotoxaemia. The levels of mRNA for CD14 on the other hand remained unaffected both during the induction of endotoxaemia and in the in vitro stimulated PBMCs. A low steady expression of TLR4, MD-2 and CD14 mRNA was demonstrated for the intestinal samples with no variation between the intestinal segments analysed. Thus, the foundation for real time PCR based levels of analysis of mRNA for all three components in the equine LPS receptor complex in different intestinal segments was set, making it possible to carry out future expression studies on clinical material., (Copyright © 2012 Elsevier B.V. All rights reserved.)