Browsing by Author "Chernyavtseva A"

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    Expression of Renal Vitamin D and Phosphatonin-Related Genes in a Sheep Model of Osteoporosis
    (MDPI (Basel, Switzerland), 2022-01) Dittmer KE; Chernyavtseva A; Marshall JC; Cabrera D; Wolber FM; Kruger M; Bienko M; Radzki RP
    Osteoporosis is a significant public health issue around the world, with post-menopausal osteoporosis due to estrogen deficiency resulting in approximately ¾ of cases. In this study, 18 aged Merino ewes were ovariectomized, and 10 were controls. Three of the ovariectomized ewes were treated weekly with 400 mg of methylprednisolone for 5 months and three were treated weekly for 2 months, followed by a 3-month recovery period. At 2 months, five control animals and six ovariectomized animals were euthanized. At 5 months, all the remaining ewes were euthanized. Kidney samples were collected postmortem for qPCR analysis of NPT1, PTH1R, NPT2a, NPT2c, Klotho, FGFR1IIIc, VDR, CYP24A1, CYP27B1, TRPV5, TRPV6, CalD9k, CalD28k, PMCA and NCX1. Ovariectomized sheep had significantly greater VDR expression compared with other groups. Ovariectomized sheep treated with glucocorticoids for 2 months followed by euthanasia at 5 months showed significant differences in TRPV5, CYP24A1 and klotho gene expression compared to other groups. Differences in klotho expression were most marked after adjustment for repeated measures (p = 0.1). Klotho is known as the "anti-aging" hormone and is involved in calcium and phosphorus metabolism. Klotho may be involved in the recovery of bone mineral density in ovariectomized sheep treated with glucocorticoids for 2 months followed by euthanasia at 5 months. Further research on the role of klotho is recommended.
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    Investigation of post-vaccinal canine distemper involving the Rockborn-like strain in nine puppies in New Zealand
    (Taylor and Francis Group on behalf of the New Zealand Veterinary Association, 2025-04-09) Gulliver E; Taylor H; Eames M; Chernyavtseva A; Jauregui R; Wilson A; Bestbier M; O’Connell J; Buckle K; Castillo-Alcala F
    Case history: This report details investigations into nine cases of neurological disease and/or sudden death in 8–13-week-old puppies between 2021 and 2024. Aside from two pairs of littermates, cases were unrelated. The puppies had an onset of clinical signs 9–23 days following at least one “on-label” dose of a commercially available quadrivalent vaccine containing live attenuated canine distemper virus (CDV). Clinical findings: Eight of the nine cases displayed signs typical of “classic distemper,” including seizures, circling, tremors, hypersalivation, progressive neurological deficits, pyrexia, and/or respiratory and gastrointestinal signs. Pathological and molecular investigations were undertaken in eight cases. Mononuclear/lymphohistiocytic encephalitis or meningoencephalitis with or without neuronal intranuclear inclusion bodies was present in seven cases. Five cases had bronchopneumonia. Other lesions included poliomyelitis, necrotising enteritis and myocardial necrosis or myocarditis. PCR for CDV was positive on tissues from seven cases, and immunohistochemistry for CDV was positive on neural tissues in six cases. Whole genome sequencing of PCR amplicons demonstrated a Rockborn-like strain with 99.9% homogeneity between samples from four cases and a vial of vaccine. Diagnosis: Based on the combination of case history, pathological findings, molecular test results and/or whole genome sequencing, a diagnosis of post-vaccinal canine distemper was confirmed in six cases and presumed in two. Clinical relevance: Outbreaks of canine distemper have been stemmed by widespread vaccination starting in the mid-twentieth century. Consequently, confirmed cases of natural CDV have not been reported in New Zealand since an outbreak in the 1980s, and CDV is considered a “notifiable organism” as per the Biosecurity Act 1993. This is the first case series to report genomic investigation of post-vaccinal canine distemper in New Zealand puppies and highlights a rare adverse event associated with routine vaccination. Our results suggest that puppies with neurological, respiratory and/or gastrointestinal disease with an onset within 6 weeks of vaccination with live attenuated CDV should be reported and investigated accordingly.
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    Uncoupling Molecular Testing for SARS-CoV-2 From International Supply Chains
    (Frontiers Media S.A., 2022-01-24) Stanton J-AL; O'Brien R; Hall RJ; Chernyavtseva A; Ha HJ; Jelley L; Mace PD; Klenov A; Treece JM; Fraser JD; Clow F; Clarke L; Su Y; Kurup HM; Filichev VV; Rolleston W; Law L; Rendle PM; Harris LD; Wood JM; Scully TW; Ussher JE; Grant J; Hore TA; Moser TV; Harfoot R; Lawley B; Quiñones-Mateu ME; Collins P; Blaikie R; Sørensen JL
    The rapid global rise of COVID-19 from late 2019 caught major manufacturers of RT-qPCR reagents by surprise and threw into sharp focus the heavy reliance of molecular diagnostic providers on a handful of reagent suppliers. In addition, lockdown and transport bans, necessarily imposed to contain disease spread, put pressure on global supply lines with freight volumes severely restricted. These issues were acutely felt in New Zealand, an island nation located at the end of most supply lines. This led New Zealand scientists to pose the hypothetical question: in a doomsday scenario where access to COVID-19 RT-qPCR reagents became unavailable, would New Zealand possess the expertise and infrastructure to make its own reagents onshore? In this work we describe a review of New Zealand's COVID-19 test requirements, bring together local experts and resources to make all reagents for the RT-qPCR process, and create a COVID-19 diagnostic assay referred to as HomeBrew (HB) RT-qPCR from onshore synthesized components. This one-step RT-qPCR assay was evaluated using clinical samples and shown to be comparable to a commercial COVID-19 assay. Through this work we show New Zealand has both the expertise and, with sufficient lead time and forward planning, infrastructure capacity to meet reagent supply challenges if they were ever to emerge.