OBJECTIVETo investigate the effect of D-AP5 (D-2-amino-5-phosphonopentanoate, a specific NMDA-antagonist) on the increase of intracellular free Ca2+ concentration ([Ca2+]i) induced by glutamate in isolated cochlear inner hair cells (IHCs), and to detect the autoreceptors of the IHC membrane.

METHODSWhen a laser scanning confocal microscope (LSCM) was used, the exogenous glutamate (Glu)-induced changes in [Ca2+]i of isolated IHCs and OHCs of guinea pig cochlea were observed with fluo-3, a fluorescent probe for [Ca2+]i. After D-AP5 or CNQX (6--cyano--7--nitroguinoxaline--2, 3--dione, a specific AMPA- antagonist) was administered, the exogenous glutamate (Glu)-induced changes in [Ca2+]i of isolated IHCs were recorded.

RESULTSIn the presence of a low concentration Glu (3.85 mumol/L), there was an increase of [Ca2+]i in IHCs, whereas there was no change in OHCs. When 50 mumol/L of D-AP5 was administrated in advance, Glu did not induce a corresponding increase in [Ca2+]i in IHCs, and 50 mumol/L of CNQX did not completely block the increase of [Ca2+]i in IHCs.

CONCLUSIONSThese results suggest that the autoreceptors existing in the IHC membrane are mainly of NMDA type, while there are relatively few AMPA receptors. Exogenous Glu is capable of increasing [Ca2+]i in IHCs by acting on the NMDA autoreceptor of IHCs in a positive feedback manner.

2-Amino-5-phosphonovalerate ; pharmacology ; 6-Cyano-7-nitroquinoxaline-2,3-dione ; pharmacology ; Animals ; Calcium ; metabolism ; Excitatory Amino Acid Antagonists ; pharmacology ; Glutamic Acid ; pharmacology ; Guinea Pigs ; Hair Cells, Auditory, Inner ; drug effects ; metabolism ; In Vitro Techniques ; Receptors, N-Methyl-D-Aspartate ; antagonists & inhibitors

Objective:To explore whether interactive learning mode can improve learning ability of medical students.Methods:From September 2017 to January 2018, there were 266 medical undergraduate interns of Grade 2014 in the department of pediatrics of the First Affiliated Hospital of Xi'an Jiaotong University. Interactive approach mode was used in pediatric probation teaching of hematological disease. And the questionnaire and final exam grade were used to evaluate the effect of interactive approach in pediatric clinical practice teaching and understand students' satisfaction with interactive learning. The test results were compared with those of 146 Grade 2013 students, who studied in the same period of 2016 and adopted traditional teaching methods. Data were analyzed using SPSS 19.0 software.Results:In the questionnaire survey, the interactive approach mode was believed to improve the learning enthusiasm by 95.8% (230/240) students, improve the ability of language expression by 97.5% (234/240) students, promote the knowledge understanding and memory by 93.3% (224/240) students, and enhance the ability of self-study and by 90.9% (218/240) students. Additionally, the mode was believed to facilitate the ability of analyzing and resolving problems by 94.2% (226/240) students, and enhance the ability of information technology, such as information retrieval ability, PPT production ability, by 96.2% (231/240) students. Moreover, the test results of students using interactive approach model mode were significantly higher than those using traditional teaching mode ( P<0.01). In the questionnaire survey, there were 92.5% (222/240) students accepting interactive approach mode. Conclusion:The teaching mode of interactive approach can improve the learning enthusiasm and learning ability of medical students, which is worthy of popularization and application in the probationary courses.

Objective: To establish a set of rules for autoverification of blood analysis, in order to provide a way to validate autoverification rules for different analytical systems, which can ensure the accuracy of test results as well as shorten turnaround time (TAT) of test reports. Methods: A total of 34 629 EDTA-K2 anticoagulated blood samples were collected from multicenter cooperative units including the First Hospital of Jinlin University during January 2017 to November 2017. These samples included: 3 478 cases in Autoverification Establishment Group, including 288 cases for Delta check rules; 5 362 cases in Autoverification Validation Group, including 2 494 cases for Delta check; 25 789 cases in Clinical Application Trial Group. All these samples were analyzed for blood routine tests using Sysmex XN series automatic blood analyzers.Blood smears, staining and microscopic examination were done for each sample; then the clinical information, instrument parameters, test results and microscopic results were summarized; screening and determination of autoverification conditions including parameters and cutoff values were done using statistical analysis. The autoverification rules were input into Sysmex Laboman software and undergone stage Ⅰ validation using simulated data, and stage Ⅱ validation for post-analytical samples successively. True negative, false negative, true positive, false positive, autoverification pass rate and passing accuracy were calculated. Autoverification rules were applied to autoverification blood routine results and missed detection rates were validated, and also data of autoverification pass rate and TAT were obtained. Results: (1)The selected autoverification conditions and cutoff values included 43 rules involving WBC, RBC, PLT, Delta check and abnormal characteristics. (2)Validation of 3 190 cases in Autoverification Establishment Group showed the false negative rate was 1.94%(62/3 190)(P<0.001), autoverification pass rate was 76.74%, passing accuracy was 97.47%; Validation of 2 868 cases in Autoverification Validation Group, the false negative rate was 3.38%(97/2 868)(P=0.002), autoverification pass rate was 42.26%, passing accuracy was 92.00%; Validation of Delta check on 288 cases in Autoverification Establishment Group and 2 494 cases in Autoverification Validation Group showed the false negative rates were respectively 1.39% and 2.61%(P<0.001). (3)Three hospitals adopted these rules of autoverification for 25 789 blood routine samples, and found that the average TAT of blood routine test reports were shortened by 24min, 32min and 7min respectively, the rate of samples reported within 30min were elevated by 33%, 53% and 7%. The autoverification pass rates were 72%-74%. Conclusions The application of this set of 43 autoverification rules in blood sample analysis can ensure test quality while shortenTAT and improve work efficiency. It is worth pointing out that for the same analytical systems in this research, validation is necessary before application of this set of rules, and periodic validation is required during application to make necessary adjustment; for different analytical systems, as this research provide a way to establish autoverification rules for blood routine tests.Clinical labs may establish their own suitable autoverification rules on the basis of technological parameters. (Chin J Lab Med, 2018, 41: 601-607)