Osteoarthritis (OA) is a degenerative disease of middle-aged and elderly people, contributed a higher burden of disease in China and the world. In 2017, under the support of the Rheumatology and Immunology Expert Committee of the Cross-Strait Medical and Health Exchange Association. The objective was to develop an evidence-based diagnosis and treatment guideline for OA in China based on emerging new evidence. The guideline was registered at International Practice Guidelines Registry Platform (IPGRP-2018CN028). The grading of recommendations assessment, development and evaluation (GRADE) approach was used to rate the quality of evidence and the strength of recommendations, and the RIGHT (Reporting Items for Practice Guidelines in Healthcare) checklist was followed to report the guideline. The guideline provides recommendations for the OA diagnosis, disease risks monitoring and evaluate, treatment purpose and physical, medical and surgical interventions. This guideline is intended to serve as a tool for Chinese clinicians for the best decisions-making on diagnosis and treatment of OA.

Brown blight disease caused by Colletotrichum species is a common and serious foliar disease of tea (Camellia sinensis). Fungal isolates from several tea plantations causing typical brown blight symptoms were identified as belonging to the Colletotrichum acutatum species complex and the Colletotrichum gloeosporioides species complex based on morphological characteristics as well as DNA analysis of the internal transcribed spacer (ITS) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Colletotrichum acutatum, a new causal agent associated with C. sinensis, showed high phenotypic and genotypic diversity compared with the more commonly reported C. gloeosporioides. Phylogenetic analysis derived from individual and combined ITS and GAPDH sequences clearly clustered C. acutatum and C. gloeosporioides into separate species. Pathogenicity tests validated that both species were causal agents of tea brown blight disease and were highly pathogenic to tea leaves. However, the two groups of C. gloeosporioides with low levels of variability within their ITS and GAPDH regions differed in their virulence. This study reports for the first time the characterization of C. acutatum and C. gloeosporioides causing brown blight disease on tea (Camellia sinensis (L.) O. Kuntze) in China.

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RNA silencing is an important mechanism of antiviral defence in plants. To counteract this resistance mechanism, many viruses have evolved RNA silencing suppressors. In this study, we analysed five proteins encoded by Sweet potato chlorotic fleck virus (SPCFV) for their abilities to suppress RNA silencing using a green fluorescent protein (GFP)-based transient expression assay in Nicotiana benthamiana line 16c plants. Our results showed that a putative nucleotide-binding protein (NaBp), but not other proteins encoded by the virus, could efficiently suppress local and systemic RNA silencing induced by either sense or double-stranded RNA (dsRNA) molecules. Deletion mutation analysis of NaBp demonstrated that the basic motif (an arginine-rich region) was critical for its RNA silencing suppression activity. Using confocal laser scanning microscopy imaging of transfected protoplasts expressing NaBp fused to GFP, we showed that NaBp accumulated predominantly in the nucleus. Mutational analysis of NaBp demonstrated that the basic motif represented part of the nuclear localization signal. In addition, we demonstrated that the basic motif in NaBp was a pathogenicity determinant in the Potato virus X (PVX) heterogeneous system. Overall, our results demonstrate that the basic motif of SPCFV NaBp plays a critical role in RNA silencing suppression, nuclear localization and viral pathogenesis.

Gray blight of tea, caused by several Pestalotiopsis-like species, is one of the most destructive foliar diseases in tea cultivation yet the characteristics of these pathogens have not been confirmed until now. With morphological and multigene phylogenetic analyses, we have identified the gray blight fungi as Pseudopestalotiopsis camelliae-sinensis, Neopestalotiopsis clavispora, and Pestalotiopsis camelliae. Phylogenetic analyses derived from the combined internal transcribed spacer, β-tubulin, and translation elongation factor 1-α gene regions successfully resolved most of the Pestalotiopsis-like species used in this study with high bootstrap supports and revealed three major clusters representing these three species. Differences in colony appearance and conidia morphology (shape, size, septation, color and length of median cells, and length and number of apical and basal appendages) were consistent with the phylogenetic grouping. Pathogenicity tests validated that all three species isolated from tea leaves were causal agents of gray blight disease on tea plant (Camellia sinensis). This is the first description of the characteristics of the three species Pseudopestalotiopsis camelliae-sinensis, N. clavispora, and Pestalotiopsis camelliae as causal agents of tea gray blight disease in China.