Alzheimer’s disease is a progressive， fatal， and neurodegenerative disease， clinically characterized by gradually developed cognitive and memory function decline， language and visuospatial disorders， and other aspects. It remains incurable and irreversible to date. In clinical settings， Alzheimer’s disease usually faces the possibility of untimely diagnosis， causing difficulties in the early intervention of the disease. Thus， it is essential to improve diagnostic efficiency and help patients diagnose Alzheimer’s disease as early as possible. With the continuous development of artificial intelligence （AI） technology， its application in Alzheimer’s disease imaging diagnosis has shown great potential. Meanwhile， it is also accompanied by many ethical issues. By exploring the ethical challenges brought by AI in the research and application of Alzheimer’s disease imaging diagnosis， such as data security， interpretability， algorithmic discrimination， and disclosure of incidental findings， the paper proposed the corresponding countermeasures， with a view to providing certain ethical guidance for the AI application in medical imaging diagnosis， protecting the rights and interests of subjects/patients， and promoting the healthy development of technology.

OBJECTIVES: Neurodegenerative diseases are closely associated with myelin loss, and the proliferation and differentiation of oligodendrocyte precursor cells (OPCs) are crucial to remyelination. However, the regulatory mechanisms involved remain incompletely understood. This study aims to investigate how astrocytes (ASTs) regulate the secretion of chitinase-3-like protein 1 (CHI3L1) via connexin 47 (Cx47)-mediated exosome signaling, and its subsequent effect on OPC proliferation. METHODS: Primary cells were isolated from postnatal day 1 Sprague-Dawley (P1SD) rats to establish 3 culture conditions: OPCs alone (Group O), OPCs in direct contact with ASTs (Group C), and OPCs cultured with AST-conditioned medium (Group A). Cellular morphology and proliferation were assessed using optical microscopy, 5-ethynyl-2'- deoxyuridine (EdU) incorporation, and flow cytometry. RNA sequencing (RNA-Seq) and bioinformatics analysis (BA) were conducted to identify differentially expressed genes (DEGs) among groups. Protein expression and cell cycle distribution were analyzed by Western blotting (WB) and flow cytometry. Exosomes were isolated and purified via differential centrifugation, characterized by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM), and CHI3L1 expression in exosomes was verified via WB. Cx47 was silenced using small interfering RNA (siRNA) to evaluate its effect on OPC proliferation and exosome secretion. Artificial exosomes were constructed by encapsulating CHI3L1 in single unilamellar vesicles (SUVs), whose structure and size were validated by NTA and TEM. Following Cx47 knockdown, artificial exosomes were added back, and OPC proliferation was assessed via flow cytometry and EdU assay. RESULTS: Direct co-cultured with ASTs (Group C) resulted in significantly enhanced OPC proliferation compared to the Group O and Group A (P<0.05). RNA-Seq and WB analyses revealed that ASTs promote OPC proliferation and exosome secretion enriched in CHI3L1 through Cx47. Cx47 knockdown by siRNA led to significant decreases in OPC proliferation and exosome release (P<0.05). The inhibitory effect of Cx47 silencing on OPC proliferation was partially reversed by supplementation with either isolated exosomes or exogenous CHI3L1. CONCLUSIONS This study reveals a novel mechanism by which ASTs regulate OPC proliferation: Through direct contact, ASTs enhance the secretion of CHI3L1-rich exosomes via Cx47, thereby converting intercellular contact signals into secretory signals that promote OPC proliferation. As a key exosomal molecule, CHI3L1 may play an important role in neural function and remyelination and warrants further investigation.
Animals ; Exosomes/metabolism* ; Cell Proliferation ; Rats, Sprague-Dawley ; Rats ; Connexins/genetics* ; Oligodendrocyte Precursor Cells/metabolism* ; Astrocytes/metabolism* ; Chitinase-3-Like Protein 1/metabolism* ; Cells, Cultured ; Cell Differentiation

This study used the Appraisal of Guidelines Research & Evaluation-Health Systems （AGREE-HS） to demonstratively compare 34 global coronavirus disease-2019 （COVID-19） health systems guidance documents （HSGs） and 6 World Health Organization （WHO） standard HSGs. The comparison involved topic， participants， methods， recommendations， and implementability， with the aim of exploring the characteristics of emergency HSGs. The results showed that the emergency HSGs had an overall average score of 49%， with topic having the highest score， recommendations having the second highest score， and participants having the lowest score. The standard HSGs had an overall average score of 79%， with high scores in all items. The emergency HSGs had lower scores in participants， methods， recommendations， and implementability than the standard HSGs （P<0.001）， while the COVID-19 emergency HSGs developed by the WHO had higher score in topic than the standard HSGs （P<0.05）. Compared with those released by countries， the COVID-19 emergency HSG developed by the WHO showed superiority in all items and overall scores （P=0.000 2）. This indicates that emergency HSGs， represented by the COVID-19 emergency HSG， place equal emphasis on topic and recommendations as standard HSGs but have low requirements in terms of expert participation， evidence support， and comprehensive consideration in the time- and resource-limited context. They have the characteristics of prominent topics， clear purposes， orientation to demand， keeping up with the latest evidence， flexible adjustment， and timeliness， emphasizing immediate implementation effects， weakening long-term effects， and focusing on comprehensive benefits. Additionally， developers， types， and report completeness are important influencing factors.

Standardized reporting is a crucial factor affecting the use of patient guidelines （PGs）， particularly in the reporting and presentation of recommendations. This paper introduced the current status of PG reporting， including the research on PG content and presentation formats， and provided comprehensive recommendations for PG reporting from aspects such as overall framework， recommendations， presentation format， and readability. First， the presentation of PG recommendations should include clearly defined clinical questions， recommendations and their rationale， and guidance on how patients should implement the interventions； for specific content in the PG， such as level of evidence， level of recommendation， it is recommended to explain in text the reasons for giving different levels of recommendation， i.e.， to present the logic behind giving the level of recommendation to the patient； additional information needed in the recommendation framework should be supplemented by tracing references or authoritative textbooks and literature that support the recommendations. Subsequently， the PG text should be written based on the Reporting Checklist for Public Versions of Guidelines （RIGHT-PVG） reporting framework. Finally， to enhance readability and comprehension， it is recommended to refer to the Patient Education Materials Assessment Tool （PEMAT） for translating PG content. To enhance the readability of PGs， it is suggested to present the PG content in a persona-lized and layered manner.

Objective:To study the effects of periodontitis on bone and tryptophan metabolism of gut microbiota in the context of estrogen deficiency.Methods:Thirty-two female C57BL6/J mice were randomly divided into four groups based on table of random numbers ( n=8 in each group): Sham group, in which mice were given sham surgery; Sham_Lig group, in which mice were given sham surgery and were induced to periodontitis by ligating the bilateral maxillary second molars with 5-0 silk threads at the fourth week; Ovx group, in which mice were given bilateral ovariectomy; Ovx_Lig group, in which mice were given bilateral ovariectomy and were induced to periodontitis at the fourth week. After 8 weeks of ligation, the mice of 4 groups were euthanized for collecting the samples of femur, tibia, mandible and skull. Those samples were scanned by micro-CT to measure the bone mineral density (BMD), bone volume versus total volume ratio (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th) and trabecular spacing (Tb.Sp). The cecum contents of 4 groups of mice were collected for gut microbiota 16S rRNA gene sequencing. The tryptophan and its metabolites in intestinal tracts were detected by liquid chromatography-mass spectrometry. Pearson correlation analysis was performed to analyze the correlation between the abundance of gut microbiota and the content of tryptophan and its metabolites. Results:Femur BMD [(82.23±3.97) mg/cm 3], BV/TV [(9.25±1.37)%] and Tb.Th [(70.95±5.70) μm] in Ovx_Lig group were significantly lower than Ovx group [(96.30±3.76) mg/cm 3 ( P=0.004); (14.45±1.55)% ( P=0.022) and (87.58±8.02) μm ( P<0.001), respectively]. The β-diversity analysis of gut microbiota based on Bray-Curtis distance showed that samples of Ovx_Lig group and Ovx group were obviously grouped. Linear discriminant analysis effect size (LEfSe) showed that Alistipes was the representative genus in Ovx_Lig group. The relative abundance of Alistipes in Ovx_Lig group [(0.42±0.14)%] were significantly higher than that in Ovx group [(0.17±0.05)%] ( t=4.45, P<0.001). Tryptophan metabolism analysis showed that the content of kynurenic acid [(531.12±158.60) ng/g] in Ovx_Lig group were significantly higher than that in Ovx group [(400.42±57.96) ng/g] ( t=2.19, P=0.046). And the content of indole-3-carbaldehyde [(383.37±144.06) ng/g] in Ovx_Lig group were significantly lower than Ovx group [(701.72±141.93) ng/g] ( t=4.45, P<0.001). Correlation analysis showed that relative abundance of Alistipes was positively correlated with kynurenic acid ( r=0.32, P=0.088), while negatively correlated with indole-3-carbaldehyde ( r=-0.32, P=0.088). Conclusions:Periodontitis can induce bone destruction of femur in estrogen-deficient mice, the mechanism of which may be related to Alistipes in gut and the tryptophan metabolites kynurenic acid and indole-3-carbaldehyde.

Rapid and living guidelines are those developed in response to public health emergencies in a short period of time using a scientific and standardized approach. Subsequently， they provide timely and credible recommendations for decision makers through regular and frequent updates of clinical evidence and recommendations. In this paper， we introduced the definition of rapid and living guideline as well as analyzed the basic characteristics of eight rapid and living guidelines in the field of traditional Chinese medicine （TCM） published till 2023 June， summarizing three core methodological issues in relation to how to rapidly develop guidelines， how to formulate recommendations when there is lack of evidence， and how to ensure the timeliness of guidelines. Based on the analysis of current rapid and living guidelines， it is implicated that there is necessity to carry out rapid and living guideline in the field of TCM， and the methodology of rapid integration of multivariate evidence in the field of TCM needs to be further explored； furthermore， it is necessary to further explore the obstacles of implementation of guidelines and promote timely updating， all of which provide certain theoretical references for relevant guideline developers and researchers.

It is necessary to develop rapid and living guidelines in order to improve the evidence translation and guidance for clinical practice in emergency situations， and to enhance the participation of traditional Chinese medicine （TCM） in management of emergencies. This paper introduced the process of developing rapid and living guidelines of TCM and divided it into three stages， that is preparation， rapid development and dynamic updating， which highlights the features of rapid development， high quality， and dynamic updating and the integration with the predominance of TCM. By comparing with general guidelines on composition， personnel number， timing to formulate and communication patterns of the guideline working groups， as well as the content and number of clinical questions， this paper mainly gave suggestions on how to formulate a concise but authoritative team during the preparation stage， how to efficiently manage the guideline team and promote the development process from conflict of interest management， working and communication mode adjustment， and how to formulate and update the important and prioritized clinical questions， all of which may provide reference for the development of TCM rapid and living guidelines.

The lack of direct evidence is an important problem faced in the formation of recommendations in rapid living guidelines of traditional Chinese medicine under public health emergencies， and the supplementation of indirect evidence can be a key method to solve this problem. For the collection of evidence， the type of evidence required， including direct and indirect evidence， should be clarified， and ‘direct first’ principle for selecting evidence can be set to standardize and accelerate the guideline development. When integrating evidence， recommendations can be formed directly if there is sufficient direct evidence， while regarding insufficient direct evidence， recommendations need to be supplemented and improved by integrating indirect evidence. In addition， when the body of evidence contains evidence from multiple sources， it is suggested to rate the evidence according to “higher rather than lower” principle. Finally， when forming recommendations， the level of evidence， safety and economic efficiency should be taken into consideration to determine the strength of the recommendation.

In developing rapid and living guidelines of traditional Chinese medicine （TCM） in response to public health emergencies， it is important that evidence continue to be reviewed， and clinical questions and recommendations updated if necessary， due to the rapid changes in disease progression and the continuous generation of relevant research evidence. This paper proposed that the updating scope in dynamic mode should first be identified； then evidence monitoring should be carried out in four aspects， including clinical research， related guidelines or laws and regulations， disease progression， as well as clinical use of recommendations and clinical needs； finally， based on the results of the evidence monitoring， different options should be made， including revising the clinical questions， updating the evidence and recommendations， and withdrawing the guideline.

Since the concept of patient versions of guidelines （PVGs） was introduced into China， several PVGs have been published in China， but we found that there is a big difference between the concept of PVG at home and abroad， and the reason for this difference has not been reasonably explained， which has led to ambiguity and even misapplication of the PVG concept by guideline developers. By analyzing the background and purpose of PVGs， and the understanding of the PVG concept by domestic scholars， we proposed the term patient guidelines （PGs）. This refers to guidelines developed under the principles of evidence-based medicine， centered on health issues that concern patients， and based on the best available evidence， intended for patient use. Except for the general attribute of providing information or education， which is typical of common health education materials， PGs also provide recommendations and assist in decision-making， so PGs include both the patient versions of guidelines （PVG） as defined by the Guidelines International Network （GIN） and "patient-directed guidelines"， i.e. clinical practice guidelines resulting from the adaptation or reformulation of recommendations through clinical practice guidelines.