BACKGROUND: Among multiple signals which affect the function of melanocyte, nitrogen monoxide (NO) has been thought as an important signal molecule. Emodin hypo-acid, effective component of rhubarb, can affect proliferation of melanocyte and regulate activity of tyrosinase in cells. OBJECTIVE: To study the effect of emodin hypo-acid on expression of nitricoxide synthase (NOS) of melanocyte in skin of guinea pig and definite the effective concentrations and mechanism of melanocyte in synthesizing melanin in living skin.DESIGN: Completely randomized grouping design and controlled study.SETTING: Department of Dermatology, Affiliated Hospital of Luzhou Medical College.MATERIALS: The experiment was completed at the Infection Laboratory of Affiliated Hospital of Luzhou Medical College and Laboratory of Histology and Embryology of Luzhou Medical College from January to June 2004. A total of 24 adult healthy male guinea pigs were randomly divided into 6 groups: control group, 2, 5, 10, 20 and 40 mg/L emodin hypo-acid groups with 4 in each group.METHODS: ① Emodin hypo-acid was diluted with dimethyl-sulfoxide into 2, 5, 10, 20 and 40 mg/L, then guinea pigs in emodin hypo-acid groups were injected subcutaneously with relevant dosages of emodin hypoacid which was provided by National Institute for the Control of Pharmaceutical and Biological Products into local skins of haunch and back, and the injected volume was 1 mL. Twenty-four hours later, 1 mL emodin hypo-acid of the same concentration was injected once again into one of the places which was injected before. Skin samples were selected after 48 hours and routine paraffin section was made. Skins which were not injected with any drugs were selected from control group and emodin hypoacid groups to regard as experimental control group. ② Expression of NOS was assayed with immunohistochemical method and melanocyte was identified under high-times optic microscope to observe stain and characteristic of cytoplasm. Five sections were randomly selected from each group. Every 20 cells on each section were measured with MLAS-1000 imaging analyzer and computer processing system was used to calculate average absorbency (A) of positive immune product in melanocyte. ③ Measurement data were compared with analysis of variance, and differences among groups were compared with SNK-q.MAIN OUTCOME MEASURES: Expression of NOS in melanocyte was assayed with immunohistochemical method and results were obtained with optic microscope and imaging analyzer.RESULTS: Average A value of positive immune product in melanocyte was lower in 2, 5, 10, 20 and 40 mg/L emodin hypo-acid groups than that in experimental control group (0.126±0.118, 0.103±0.082, 0.118±0.097,0.122±0.095, 0.112±0.078, 0.196±0.066, P ＜ 0.05). There was no significant difference among emodin hypo-acid groups at various concentrations.CONCLUSION: ① Emodin hypo-acid can regulate expression of NOS in melanocyte through NO signal transduction pathway. ② Expression of NOS is not changed as the mass concentration of emodin hypo-acid varied from 2 to 40 mg/L.

In theory teaching,we let students know the knowledge of some important discovery and invention in the history of physiology and while in experiment teaching,we added the experiments designed by students in addition to traditional experiments,so as to enhance the students,ability of innovation.

DCD WeChat ethical review had its necessity and superiority but problems and confusion as well. For instance, WeChat review time was urgent and limited;WeChat review discussed insufficiently even hard to car-ry out;the methods of WeChat review were limited;the authenticity of audit opinion was difficult to grasp;the re-view data privacy existed hidden danger;the review quality was difficult to guarantee;WeChat conference content file archive was difficult, and so on. As to this, the author put forward the following countermeasures:giving war-ranty on the ethical review time as far as possible;initiating the committee review by the referee and uploading the review information to WeChat group, then ethical reviewers expressing their opinions in real names to ensure data confidentiality and privacy protection; strengthening the ethics committee education for organ transplantation; im-proving the quality of the review committee members and moral cultivation;archiving the WeChat conference infor-mation.

Currently,the ethical review model for organ donation and transplantation in domestic hospitals is generally characterized by suddenness,unpredictability,tight time,difficulty in convening meetings and training committee members,as well as generally low quality and efficiency of ethical review,which cannot meet clinical needs and cause the waste of some scarce resources.The team of the Clinical Application Center of Human Organ Transplantation and the Ethics Committee of the First People's Hospital of Kunming combine more than 10 years of review practice experience,as well as continuously explore and optimize the ethical review process and operating procedures for organ donation and transplantation.The special application has been approved and jointly developed with Soochow University and the Medical Ethics Committee of Fujian Province to build a full-process information software system management platform for organ ethical review of donation and transplantation,giving the full play the advantages of the review information system in improving work efficiency and review quality,facilitating full-process information management,and conducting online training and learning for committee members,with a view to providing a specialized practical model for addressing the difficulties and challenges related to ethical review of human organ donation and transplantation.

The ethics committee of organ transplantation technology and clinical application in a hospital has encountered some difficulties and typical cases in its review work and practice for many years. Sometimes, it is difficult to make a decision in these dilemmas. Based on the previous experience of the hospital in the ethical review of organ donation and transplantation, combined with two typical cases, this paper discussed and analyzed two review points of whether the voluntary unpaid donation and the principle of informed consent were met, and whether the risk-benefit ratio was reasonable, and put forward relevant ethical and legal countermeasure for further research by institutional ethics committees and other parties, in order to provide reference for discussing the practical problems and ethical confusion of ethical review of organ donation and transplantation.

The ethics committee of organ transplantation technology and clinical application in a hospital has encountered some difficulties and typical cases in its review work and practice for many years. Sometimes, it is difficult to make a decision in these dilemmas. Based on the previous experience of the hospital in the ethical review of organ donation and transplantation, combined with two typical cases, this paper discussed and analyzed two review points of whether the voluntary unpaid donation and the principle of informed consent were met, and whether the risk-benefit ratio was reasonable, and put forward relevant ethical and legal countermeasure for further research by institutional ethics committees and other parties, in order to provide reference for discussing the practical problems and ethical confusion of ethical review of organ donation and transplantation.