Mutated influenza A virus exhibiting reduced susceptibility to baloxavir marboxil from an experimentally infected horse.

Baloxavir marboxil (BXM), an inhibitor of the cap-dependent endonuclease of the influenza virus polymerase acidic protein (PA), exerts an antiviral effect against influenza A virus. It has been available in Japan since March 2018. This study evaluated the antiviral efficacy of BXM against equine influenza A virus (EIV) by an experimental challenge study using horses.

Epizootiological investigation of equine herpesvirus type 1 infection among Japanese racehorses before and after the replacement of an inactivated vaccine with a modified live vaccine.

Background: Equine herpesvirus type 1 (EHV-1) infection is a major cause of pyrexias in winter among Japanese racehorses. In 2014-2015, the Japan Racing Association (JRA) changed the EHV-1 vaccine from an inactivated vaccine to a live vaccine (both produced by Nisseiken). To evaluate the effect of changing the vaccines, the capacities of these vaccines to induce virus-neutralizing (VN) antibodies were compared, and an epizootiological investigation of EHV-1 was performed at the JRA Ritto Training Center during epizootic periods from 2010-2011 to 2016-2017.

A single amino acid change in hemagglutinin reduces the cross-reactivity of antiserum against an equine influenza vaccine strain.

Equine influenza virus is an important pathogen for the horse industry because of its economic impact, and vaccination is a key control measure. Our previous work suggested that a mutation at position 144 in the hemagglutinin of Florida sublineage clade 2 viruses reduces the cross-neutralizing activity of antiserum against a former vaccine strain. To confirm this suggestion, here, we generated viruses by reverse genetics.

Development of an enzyme-linked immunosorbent assay for Getah virus infection in horses using recombinant E2 protein as an antigen.

Getah virus causes fever, skin eruptions, and limb edema in horses. For a high-throughput and time-saving method for serodiagnosis, we explored immunogenic antigens of Getah virus, and established an enzyme-linked immunosorbent assay (ELISA) using a recombinant protein. Western blot analysis using sera from infected horses showed strong reaction with viral antigens around 46 kDa corresponding to E1 or E2 glycoproteins.

Loop-mediated isothermal amplification-fluorescent loop primer assay for the genotyping of a single nucleotide polymorphism at position 2254 in the viral DNA polymerase gene of equid alphaherpesvirus 1.

We developed a loop-mediated isothermal amplification (LAMP)-fluorescent loop primer (FLP) assay for genotyping the A/G single nucleotide polymorphism (SNP) in the viral DNA polymerase gene of species (EHV-1), which is associated with the neuropathogenic potential of this virus. In addition to the use of regular LAMP primers to amplify the target region, a 5'-FAM-labeled backward loop primer (FLB) and 3'-dabcyl-labeled quencher probe (QP) were designed for annealing curve analysis of the amplification product. The QP, which contacts the FLB, is located at the SNP site and has the A allele.

Molecular analyses of G3A/G3B and G14 equine group A rotaviruses detected between 2012 and 2018 in Japan.

Equine group A rotaviruses (RVAs) cause diarrhoea in foals. We investigated the G genotypes of 360 RVA-positive samples obtained from diarrhoeic foals between 2012 and 2018 in the Hidaka district of Hokkaido, Japan, through sequence analysis of VP7. All samples were classified into genotypes G3A, G3B and G14.

Evaluation of two enzyme-linked immunosorbent assays for the detection of antibodies against equine arteritis virus.

In order to establish an efficient system for serological diagnosis of equine viral arteritis in Japan, we compared enzyme-linked immunosorbent assays (ELISAs) provided by two manufacturers (Nisseiken Co., Ltd., Tokyo, Japan, and VMRD Inc.

Comparison of protective efficacies between intranasal and intramuscular vaccination of horses with a modified live equine herpesvirus type-1 vaccine.

Immune responses were compared after intranasal (IN) and intramuscular (IM) vaccination of horses with a modified live equine herpesvirus type-1 (EHV-1) vaccine, and the protective effect after EHV-1 challenge was evaluated. IN- and IM-vaccinated groups (n = 5 each) showed significant rises in serum virus-neutralizing titers with increased levels of IgGa and IgGb antibodies after the first vaccination (P < 0.05).

Evaluation of inactivated vaccines against equine group A rotaviruses by use of a suckling mouse model.

Background: Equine group A rotaviruses (RVAs) cause diarrhea in suckling foals. The dominant RVAs circulating among horses worldwide, including Japan, are G3P[12] and/or G14P[12] genotypes. Inactivated vaccines containing a G3P[12] RVA are commercially available in some countries for prevention of diarrhea caused by equine RVAs.

Comparison of two agar gel immunodiffusion protocols for diagnosing equine infectious anemia.

This study compared agar gel immunodiffusion (AGID) protocols for diagnosing equine infectious anemia. Two commercial testing kits were used: one following the Japanese Act on Domestic Animal Infectious Diseases Control and one following the World Organisation for Animal Health (OIE) manual. From 651 samples tested, both protocols gave identical results for 647 samples (23 samples tested positive; 624 tested negative).

Complete Genomic Sequences of H3N8 Equine Influenza Virus Strains Used as Vaccine Strains in Japan.

We sequenced the eight segments of influenza A virus strains A/equine/Ibaraki/1/2007 and A/equine/Yokohama/aq13/2010, which are strains of the Florida sublineage clades 1 and 2 of the H3N8 subtype equine influenza virus. These strains have been used as vaccine strains in Japan since 2016 in accordance with World Organization for Animal Health (OIE) recommendations.

Neutralization antibody response to booster/priming immunization with new equine influenza vaccine in Japan.

Equine influenza (EI) vaccine has been widely used. However, the causative EI virus (H3N8) undergoes continuous antigenic drift, and the vaccine strains must be periodically reviewed and if necessary, updated to maintain vaccine efficacy against circulating viruses. In 2016, the Japanese vaccine was updated by replacing the old viruses with the Florida sub-lineage Clade (Fc) 2 virus, A/equine/Yokohama/aq13/2010 (Y10).

Antibody response to equine coronavirus in horses inoculated with a bovine coronavirus vaccine.

A vaccine for equine coronavirus (ECoV) is so far unavailable. Bovine coronavirus (BCoV) is antigenically related to ECoV; it is therefore possible that BCoV vaccine will induce antibodies against ECoV in horses. This study investigated antibody response to ECoV in horses inoculated with BCoV vaccine.

Complete Genome Sequences of Getah Virus Strains Isolated from Horses in 2016 in Japan.

Getah virus is mosquito-borne and causes disease in horses and pigs. We sequenced and analyzed the complete genomes of three strains isolated from horses in Ibaraki Prefecture, eastern Japan, in 2016. They were almost identical to the genomes of strains recently isolated from horses, pigs, and mosquitoes in Japan.

Wakayama symposium: modulation of wound healing response in the corneal stroma by osteopontin and tenascin-C.

The extracellular matrix components osteopontin and tenascin-C are ligands of α9 integrin, and both play roles in corneal wound fibrosis and neovascularization. It has been shown that loss of osteopontin impairs closure of incisional wounds in the mouse cornea. Detailed analyses suggest that the loss of osteopontin reduces macrophage invasion and myofibroblast differentiation in the healing stroma in association with suppression of fibrogenic gene expression in response to injury.

Three cases of iatrogenic coronary ostial stenosis after aortic valve replacement.

Background: Iatrogenic coronary ostial stenosis (ICOS) is a rare but potentially life-threatening complication of aortic valve replacement (AVR). This complication is usually diagnosed by angiography and treated with aortocoronary bypass surgery.

Case Reports: In the present 3 cases pre-operative coronary angiography confirmed normal coronary arteries and they underwent uncomplicated AVR.

Cardiac troponin T Arg92Trp mutation and progression from hypertrophic to dilated cardiomyopathy.

Background: Mutations in the cardiac troponin T gene causing familial hypertrophic cardiomyopathy (HCM) are associated with a very poor prognosis but only mild hypertrophy. To date, the serial morphologic changes in patients with HCM linked to cardiac troponin T gene mutations have not been reported.

Hypothesis: The aim of this study was to determine the long-term course of patients with familial HCM caused by the cardiac troponin T gene mutation, Arg92Trp.

Clinical features of hypertrophic cardiomyopathy caused by a Lys183 deletion mutation in the cardiac troponin I gene.

Background: Mutations that cause hypertrophic cardiomyopathy (HCM) have been identified in 9 genes that code proteins in the sarcomere. Previous reports have demonstrated that cardiac troponin I (cTnI) gene mutations may account for familial HCM; however, the clinical characteristics and prognosis of patients with HCM caused by cTnI gene mutations are not known.

Methods And Results: We analyzed cTnI gene mutations in 130 unrelated probands with HCM and their families to clarify the genotype-phenotype correlations.

Barrier properties in electrophotographic zinc oxide.

A number of factors are known to influence greatly the photoelectrical and the electrophotographical properties of zinc oxide powder. Some of them, such as the degree of zinc excess and the state-species and amount-of chemisorbed oxygen, are in most cases uncontrollable, in the sense that they are almost determined at the time of manufacturing, unless some drastic treatment is imposed on samples before use. While some other factors such as the surface doping can be used to improve or control behaviors of samples at the time of use, these factors seem to be intimately related to the hard-to-control ones.