ABSTRACT
AIM: To design a simple and effective auxiliary device for detection of the compound action poten-tial (CAP) and the force on the isolated sciatic nerve and gastrocnemius in toads, and to investigate its practicability. METHODS: A simple “L” shape device (L tube), which was composed of a nerve chamber and an organ bath, was made for fixing the isolated sciatic nerve and gastrocnemius.After fixing, the sciatic CAP and the gastrocnemius force were detected by BL-420S data acquisition and analysis system.The specimens were radomly divided into control group, and the lidocaine nerve and muscle groups.The sciatic nerve or gastrocnemius of each lidocaine group was firstly treated with the corresponding concentration of lidocaine, and then washed out with Ringer’s solution, and its reversible anesthetic action on nerve conduction and muscle force was analyzed to verify the practicability of the L tube device.RESULTS: The CAP and the force of the sciatic-gastrocnemius specimens were detected concurrently by fixing the specimens in the L tube, and the liquid in the nerve chamber and organ bath was changed easily.Compared with the control, lidocaine at 0.05 and 0.2 g/L significantly increased the sciatic threshold stimulus voltage and maximal stimulus voltage (P ly blocked the sciatic conduction.The rest tension of the gastrocnemius was increased, and the maximal twitch force was decreased significantly by 1 g/L lidocaine (P <0.01), but the threshold and maximal stimulus voltage did not show statis-tic difference.The parameters of the sicatic nerve and gastrocnemius completely or partially recovered to the control level after washing out.CONCLUSION: As an auxiliary device, L tube makes the detection of CAP and force on the isolated sciatic nerve and gastrocnemius in toads more conveniently.
ABSTRACT
[ ABSTRACT] AIM:To screen out a suitable lead for monitoring the ambulatory electrocardiogram ( ECG) in un-restrained toad, and to investigate its practicability.METHODS:After subcutaneously implanting the electrodes in toads under anaesthesia, the ambulatory ECG of 5 leads were monitored with BL-420S data acquisition and analysis system, and the leads which could well express the waveform in ECG were screened out.The recovery process of the toads from the arti-ficial hibernation within 6 h, the day-to-day stability of the heart rate ( HR) and the heart rate variability ( HRV) in 5 suc-cessive days of hibernation, and the HR and HRV after freeze-thawing process were monitored to determine its practicabili-ty.RESULTS:Two out of 5 leads showed better ECG waveforms.Compared with 6 h post hibernation, lowered HR at 0 h and 1 h was observed, and the standard deviation of normal R-R intervals ( SDNN) was significantly increased ( P<0.05 or P<0.01), but the HR and SDNN from 2 to 5 h showed no significant difference, suggesting that the cardiac function reached the steady state after 2 h recovery.The HR at 2 h and 4 h on day 4 and day 5 decreased significantly compared with that on day 1 (P<0.05 or P<0.01), followed with a significant increase in SDNN (P<0.05 or P<0.01), sugges-ting that the ECG remained stable within 3 d.The HR increased, while SDNN decreased significantly at 1 h and 12 h post-thawing compared with that at pre-freeze (P<0.05), indicating the damaged cardiac function after freeze-thawing process. CONCLUSION:The method of subcutaneously implanting electrodes is suitable for effectively monitoring the ambulatory ECG in toads.
ABSTRACT
Medical function experimental science in the medical education reform has been a hot spot in recent years. The set-up and adjustment of the curriculum is a very important step in teaching reform and one of the major issues in the research and study of medical education. In the article, it explores the initial ideas for curriculum reform, such as optimization of the course content, reform of teaching methods and means, improving student achievement evaluation system, and other aspects, to promote the development and improvement on curriculum construction in functional experimental science of medical colleges.