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An anomalous pattern of structural covariance has been reported in schizophrenia, which has been suggested to represent connectome changes during brain maturation and neuroprogressive processes. It remains unclear whether similar differences exist in a clinical high-risk state for psychosis, and if they are associated with a prodromal phenotype and/or later psychosis onset. This multicenter magnetic resonance imaging study cross-sectionally examined structural covariance in a large at-risk mental state (ARMS) sample with different outcomes. The whole-brain structural covariance of four cortical measures (thickness, area, volume, and gyrification) was assessed in 155 individuals with ARMS, who were subclassified into 26 (16.8 %) with a later psychosis onset (ARMS-P), 44 with persistent subthreshold psychotic symptoms, and 53 with the remission of psychotic symptoms (ARMS-R) during the clinical follow-up, and 191 healthy controls. The relationships of changes in structural covariance with clinical symptoms and cognitive impairments were also investigated in the ARMS subsample. Structural covariance was significantly higher in widespread cortical regions in the ARMS group than in the controls, with each cortical measure having a different pattern in affected cortical regions. The higher structural covariance of the cortical area was partly related to severe suspiciousness-persecutory ideation. Structural covariance was significantly higher, mainly in fronto-parietal gyrification, in the ARMS-P group than in the ARMS-R group. The present results suggest that changes in structural covariance result in psychosis vulnerability and the excessive structural covariance of brain gyrification in ARMS subjects may contribute to their later clinical course., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024. Published by Elsevier Inc.)

Ubiquitin-specific protease 18 (USP18) is a well-established innate immune factor in vertebrates. Although Anatidae birds rarely exhibit distinctive clinical signs during high pathogenicity avian influenza virus (HPAIV) infections, some virus strains cause deadly diseases. Here, we investigated the association between USP18 expression and pathogenicity during HPAIV infections in the Anatidae mallard Anas platyrhynchos. First, mallard USP18 gene (duUSP18) was cloned, and its transcriptional variants, with three different open reading frames, were characterized. Experimental infections with two different pathogenic strains, Miyazaki and Takeo, demonstrated an early induction of duUSP18 mRNA upon HPAIV infection in a bird's whole body in vivo and in primary duck cells in vitro, which was positively associated with pathogenicity in mallards. In addition, duUSP18 knockdown under interferon-β stimulation attenuated viral replication, regardless of pathogenicity. These results indicate a role for duUSP18 in favoring viral replication and virus resistance to type I interferon immunity in mallards., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The Goose/Guangdong-lineage (Gs/Gd) H5 high pathogenicity avian influenza viruses (HPAIVs) spread among poultry and wild birds worldwide; an association has been identified between the migration of wild birds and spread of HPAIVs. Every autumn-spring season, the mallard (Anas platyrhynchos) migrates to Japan in substantial numbers for overwintering; however, to the best of our knowledge, no virological studies have focused on mallards' susceptibility to the HPAIVs in Japan. To evaluate the susceptibility of mallards to infection with Gs/Gd H5 HPAIVs isolated during previous outbreaks in Japan, we experimentally infected the birds with various virus strains: A/chicken/Yamaguchi/7/2004 (H5N1) (clade 2.5), A/chicken/Miyazaki/K11/2007 (H5N1) (clade 2.2), A/whooper swan/Akita/1/2008 (H5N1) (clade 2.3.2), A/mandarin duck/Miyazaki/22M-765/2011 (H5N1) (clade 2.3.2.1c), A/duck/Chiba/26-372-48/2014 (H5N8) (clade 2.3.4.4c), A/duck/Hyogo/1/2016 (H5N6) (clade 2.3.4.4e) and A/mute swan/Shimane/3211A002/2017 (H5N6) (clade 2.3.4.4b). The birds exhibited high tracheal shedding for a prolonged period, particularly those infected with A/duck/Hyogo/1/2016 (H5N6). Various clinical manifestations ranging from asymptomatic to mild (corneal opacity) infections to neurological disorders accompanied by mortality were noted depending on the virus strain. Furthermore, virus-infected mallards contaminated both cohoused mallards and water in their surroundings. Thus, mallards may disseminate viruses in the environment, thereby influencing HPAI outbreaks in Japan. Therefore, mallards represent an important migratory bird species that spread HPAIVs in Japan., (Copyright © 2022 Elsevier B.V. All rights reserved.)