Background: Disorders of the blood-brain barrier (BBB) arising from diabetes mellitus are closely related to diabetic encephalopathy. Previous research has suggested that neuron-glia antigen 2 (NG2)-glia plays a key role in maintaining the integrity of the BBB. However, the mechanism by which NG2-glia regulates the diabetic BBB remains unclear. Methods: Type 2 diabetes mellitus (T2DM) db/db mice and db/m mice were used. Evans-Blue BBB permeability tests and transmission electron microscopy techniques were applied. Tight junction proteins were assessed by immunofluorescence and transmission electron microscopy. NG2-glia number and signaling pathways were evaluated by immunofluorescence. Detection of matrix metalloproteinase-9 (MMP-9) in serum was performed using enzyme-linked immunosorbent assay (ELISA). Results: In T2DM db/db mice, BBB permeability in the hippocampus significantly increased from 16 weeks of age, and the structure of tight junction proteins changed. The number of NG2-glia in the hippocampus of db/db mice increased around microvessels from 12 weeks of age. Concurrently, the expression of MMP-9 increased in the hippocampus with no change in serum. Sixteen- week-old db/db mice showed activation of the Wnt/β-catenin signaling in hippocampal NG2-glia. Treatment with XAV-939 improved structural and functional changes in the hippocampal BBB and reduced MMP-9 secretion by hippocampal NG2-glia in db/db mice. It was also found that the upregulation of β-catenin protein in NG2-glia in the hippocampus of 16-week-old db/db mice was significantly alleviated by treatment with XAV-939. Conclusion The results indicate that NG2-glia can lead to structural and functional disruption of the diabetic BBB by activating Wnt/β-catenin signaling, upregulating MMP-9, and degrading tight junction proteins.

The surrogate subjects have been gradually replaced from “legal representatives” to “guardians” in China’s relevant norms regarding the surrogate system of the right to informed consent in clinical research recently. Although this change in the expression of surrogate subjects has not altered its legal essence， it may still lead to ambiguities， confusions and deviations， in the understanding of the surrogate subjects for the right to informed consent. Therefore， this paper summarized its characteristics from three aspects， namely， the changes in relevant norms regarding the surrogate system of the right to informed consent in China’s clinical research， their differences from foreign norms， and their differences from surrogate subjects of the medical right to informed consent. On this basis， the formal identity and substantive emphasis between guardians and legal representatives were compared from a normative perspective. Subsequently， the major reasons for legislators to replace the expression of surrogate subjects were explored from three aspects， including institutional systematization， reinforcement of the best interest principle， and cultural values. Finally， corresponding implementation suggestions were proposed for situations where research participants lack guardians during the exercise of the right to informed consent in clinical research.

Objective:To study the characteristics of metabolites in lower resPiratory tract between coal workers' pneumoconiosis patients and dust exposure patients, and compare the differences of metabolites and their main metabolic pathways.Methods:From December 2020 to February 2021, through a prospective cross-sectional study, a total of 26 patients with coal workers' pneumoconiosis (metabolic group of coal workers' pneumoconiosis) were selected from the bronchoalveolar lavage treatment of coal workers' pneumoconiosis and dust exposure in the Respiratory and Critical Care Medicine Department of the 920th Hospital of the Joint Logistics Support Force during the same period. With 19 cases of dust exposure as the control group (dust exposure metabolic group), samples of alveolar lavage fluid were collected from 2 groups. Metabolites of the two groups were quantitatively analyzed by metabonomics technology, and the characteristics of metabolites and their metabolic pathways were compared. The metabolites with potential predictive value were screened by receiver operating characteristic curve (ROC curve) .Results:Through metabolomic analysis of alveolar lavage fluid in the coal workers' pneumoconiosis group and the dust contact group, a total of 28 different metabolites were screened, including trihydroxybutyric acid, alanine, ethanolamine, L-osan, proline (carboxyl), leucine, 2-hydroxyglutaric acid, proline, lactic acid, serine, valine and threonine in the coal workers' pneumoconiosis group. The levels of differential metabolites such as ornithine, isoleucine, threitol, glucose and lysine were higher ( P<0.05). The levels of different metabolites such as sarcoine, pelanoic acid, palmitic acid, heptadecanoic acid, n-butylamine, tetradecanoic acid, isobutylamine, aminoadipic acid, phosphate, uracil and cytosine were higher in the dust exposure group ( P<0.05). Two major metabolic pathways include glycine, serine and threonine metabolism, arginine and proline metabolism, biotin metabolism, and aminoacyl biosynthesis metabolism. Among the 17 metabolites increased in the coal workers' pneumoconiosis group, the AUC of threitol and lactic acid was greater than 0.8, and the specificity and sensitivity of the working characteristic curves of the two metabolites were 80% and 70%, respectively. Conclusion:There were significant differences in the metabolites of lower respiratory tract between patients with coal workers' pneumoconiosis and those exposed to dust, and the differences were related to multiple metabolic pathways. Threitol and lactic acid may have potential predictive value for pneumoconiosis.

Investigator-initiated clinical trials （IIT） are an important part of scientific and technological activities involving human study participants. Among them， high-quality IIT can be used to support the marketing and registration application of drugs， medical devices， and other products when conditions permit. Currently， there is a huge gap between IIT and industry-initiated clinical trials. The use of unlisted products in IIT has problems， such as lack of regulatory support， insufficient research funding support， the need to improve the ability of clinical research management departments， the weakness of professional clinical research teams， and the difficulty of ethics review to match the demands. The challenges could be addressed by improving regulations and conducting pilot trials on a small scale， guaranteeing adequate research funding， strengthening the construction of clinical research management systems， building professional clinical research teams， ensuring the quality of ethical reviews and strict follow-up reviews， shifting from ethical reviews to a system for protecting research participants， and reinforcing training for researchers. Ethics committees should strictly review key points， such as the risk-benefit ratio， informed consent， research funding， compensation for damages， qualifications and equipment of research team members， and management of conflict of interest.

Radiopharmaceuticals play an important role in the diagnosis and treatment of cardiovascular and cerebrovascular diseases， malignant tumors， central nervous system diseases， and other diseases. Under the urgent need for clinical diagnosis and treatment as well as medical development， the clinical research of radiopharmaceuticals has become a hotspot in international research. By analyzing the current situation of clinical research on radiopharmaceuticals in Europe， America， and China， the ethical issues of clinical research on radiopharmaceuticals were elaborated from four aspects， including lack of relevant laws and regulations， a higher risk of radiopharmaceuticals， dilemmas in ethical review， and insufficient radiation protection. Response principles and measures were proposed from four aspects， including improving regulations and policies， enhancing radiological protection for all parties involved in the research， strengthening ethical review， and reinforcing the training of relevant personnel， to enhance the quality and level of clinical research on radiopharmaceuticals.

Objective:As the " Administrative Measures for Conducting investigator-initiated Clinical Research in Medical and Health Institutions" promulgated, to explore the key points and difficulties in the management of Investigator-Initiated Trials(IIT) in healthcare institutions, and provide basis for promoting the standardization and high-quality management of IIT.Methods:On the basis of policy text research , through literature investigation and working practice, this paper analyzes new requirements of the Management Measures for clinical trials management and puts forward implementation suggestions.Results:The Administrative Measures put forward new requirements for the implementation and management of clinical trials from the aspects of scientific review and ethical review, and carried out intervention research beyond the scope, clinical research management committee responsibilities. Medical and carried institutions need to strengthen the management of the whole process of clinical trials implementation.Conclusions:Medical and health institutions can strengthen clinical trials management by building the organizational structure of clinical trials whole-process management, hierarchical risk management, taking scientific review as the starting point, opening up all aspects of project management, focusing on process management, and strengthening quality control and quality assurance.

Objective:To study the characteristics of metabolites in lower resPiratory tract between coal workers' pneumoconiosis patients and dust exposure patients, and compare the differences of metabolites and their main metabolic pathways.Methods:From December 2020 to February 2021, through a prospective cross-sectional study, a total of 26 patients with coal workers' pneumoconiosis (metabolic group of coal workers' pneumoconiosis) were selected from the bronchoalveolar lavage treatment of coal workers' pneumoconiosis and dust exposure in the Respiratory and Critical Care Medicine Department of the 920th Hospital of the Joint Logistics Support Force during the same period. With 19 cases of dust exposure as the control group (dust exposure metabolic group), samples of alveolar lavage fluid were collected from 2 groups. Metabolites of the two groups were quantitatively analyzed by metabonomics technology, and the characteristics of metabolites and their metabolic pathways were compared. The metabolites with potential predictive value were screened by receiver operating characteristic curve (ROC curve) .Results:Through metabolomic analysis of alveolar lavage fluid in the coal workers' pneumoconiosis group and the dust contact group, a total of 28 different metabolites were screened, including trihydroxybutyric acid, alanine, ethanolamine, L-osan, proline (carboxyl), leucine, 2-hydroxyglutaric acid, proline, lactic acid, serine, valine and threonine in the coal workers' pneumoconiosis group. The levels of differential metabolites such as ornithine, isoleucine, threitol, glucose and lysine were higher ( P<0.05). The levels of different metabolites such as sarcoine, pelanoic acid, palmitic acid, heptadecanoic acid, n-butylamine, tetradecanoic acid, isobutylamine, aminoadipic acid, phosphate, uracil and cytosine were higher in the dust exposure group ( P<0.05). Two major metabolic pathways include glycine, serine and threonine metabolism, arginine and proline metabolism, biotin metabolism, and aminoacyl biosynthesis metabolism. Among the 17 metabolites increased in the coal workers' pneumoconiosis group, the AUC of threitol and lactic acid was greater than 0.8, and the specificity and sensitivity of the working characteristic curves of the two metabolites were 80% and 70%, respectively. Conclusion:There were significant differences in the metabolites of lower respiratory tract between patients with coal workers' pneumoconiosis and those exposed to dust, and the differences were related to multiple metabolic pathways. Threitol and lactic acid may have potential predictive value for pneumoconiosis.

Objective:As the " Administrative Measures for Conducting investigator-initiated Clinical Research in Medical and Health Institutions" promulgated, to explore the key points and difficulties in the management of Investigator-Initiated Trials(IIT) in healthcare institutions, and provide basis for promoting the standardization and high-quality management of IIT.Methods:On the basis of policy text research , through literature investigation and working practice, this paper analyzes new requirements of the Management Measures for clinical trials management and puts forward implementation suggestions.Results:The Administrative Measures put forward new requirements for the implementation and management of clinical trials from the aspects of scientific review and ethical review, and carried out intervention research beyond the scope, clinical research management committee responsibilities. Medical and carried institutions need to strengthen the management of the whole process of clinical trials implementation.Conclusions:Medical and health institutions can strengthen clinical trials management by building the organizational structure of clinical trials whole-process management, hierarchical risk management, taking scientific review as the starting point, opening up all aspects of project management, focusing on process management, and strengthening quality control and quality assurance.

In the implementation of exemption from ethical review,medical institutions equate exemption from ethical review with no ethical review or simple review,misunderstand the scope of exemption from ethical review,confuse the concepts of de-identification and anonymization,and equate privacy with personal information.The implementation faced challenges such as the coordination of conditions for exempt review with other regulations,the lack of clear decision-making subjects for exempting from ethical review,the legality and compliance of using general informed consent for biological samples and information data,as well as non-traceability and the risk of being re-identified of anonymous information for exemption from ethical review.Measures such as improving relevant laws and regulations,perfecting the construction and management of information databases and biological sample libraries,strengthening the project management and process supervision of exemption from ethical review,and implementing scientific review can ensure the legal and compliant implementation of exemption from ethical review by medical and health institutions.

As a structural barrier, the blood-brain barrier (BBB) is located at the interface between the brain parenchyma and blood, and modulates communication between the brain and blood microenvironment to maintain homeostasis. The BBB is composed of endothelial cells, basement membrane, pericytes, and astrocytic end feet. BBB impairment is a distinguishing and pathogenic factor in diabetic encephalopathy. Diabetes causes leakage of the BBB through downregulation of tight junction proteins, resulting in impaired functioning of endothelial cells, pericytes, astrocytes, microglia, nerve/glial antigen 2-glia, and oligodendrocytes. However, the temporal regulation, mechanisms of molecular and signaling pathways, and consequences of BBB impairment in diabetes are not well understood. Consequently, the efficacy of therapies diabetes targeting BBB leakage still lags behind the requirements. This review summarizes the recent research on the effects of diabetes on BBB composition and the potential roles of glial and vascular cells as therapeutic targets for BBB disruption in diabetic encephalopathy.