Metacercariae of Microphalloides japonicus were isolated from five kinds of crab which were collected at the Delta areas of Naktong river. These metacercariae were fed to experimental animals. Some of these metacercariae were also incubated in screw cap tube at 37 C. The longevity and developmental difference between flukes grown in vivo and in vitro were described. The total number of crabs examined were 2245 and Helice tridens tridens showed highest incidence among five species of brackish water crabs. Some of these metacercariae were fed experimentally to mice and rats, and the mature worms were obtained in the host intestine 24, 48, and 72 hours after infection. The adult and larval morphology of this fluke was described. Utilizing three kinds of medium, the adult worms of Microphalloides japonicus have been successfully developed under axenic conditions in vitro. Eggs containing adult worm were obtained in all of three media, i.e., Ringer's solution, Tyrode's solution, and Serum-Tyrode (1:1) solution. The adult worms were morphologically similar to flukes grown in vivo, but there were certain degree of difference between adult flukes grown in vivo and in vitro.
parasitology ; epidemiology-helminth ; trematoda ; Microphalloides japonicus ; metacercaria ; Helice tridens tridens ; Ringer's solution ; Tyrode's solution ; Serum-Tyrode (1:1) solution

OBJECTIVE: To quantitatively investigate the effects of Ringer's solution with different concentrations of alcohol (1%～80%) on biphasic compound action potentials (AP) from frog sciatic nerve trunk, and their recoveries from alcohol effects. METHODS: Individual segments of frog sciatic nerve trunk with a length of 6 to 8 cm were prepared. Ringer's solution with different concentrations of alcohol (0%, 1%, 2%, 4%, 8%, 16%, 32%, 48%, 64% and 80%) was applied onto the segment of the trunk between the stimulus and ground electrodes via an agent reservoir which was newly armed in a nerve trunk shielded chamber for 5 minutes. The nerve trunk was respectively electro-stimulated to generate the biphasic compound AP which was recorded using the experimental system of BL-420F. This was followed by 5 times washout plus 5 min administration with Ringer's solution before recovery recording of AP. RESULTS: Compared to normal Ringer's solution, Ringer's solution with alcohol at ≤4% did not have dramatic impacts on the AP amplitude and conduction velocity, while Ringer's solution with alcohol at ≥8% there was significant decrease in these two parameters. Ringer's solution with alcohol at the conentrations of 16%, 32% and ≥48% could prevent a small proportion (30%), a large proportion (90%) and all (100%) of sciatic nerve trunks, respectively, from generating AP. Washout with normal Ringer's solution after alcohol application at the concentration of ≤32%, AP could totally recover to normal status. While alcohol at the concentration of 48%, 64% and 80%, the probabilities to regenerate APs were 90%, 40% and 0%, and the AP amplitudes were decreased to 60%, 36% and 0%, respectively. After washout, AP conduction velocity showed no difference with alcohol at the concentration of ≤8% when compared with that before washout, while it could not be recovered to normal under alcohol at ≥16%. CONCLUSION Ringer's solution with different concentrations of alcohol exerts different effects on biphasic compound AP amplitude and conduction velocity. Hopefully, our findings could be helpful for the alcoholic usage and its recovery from alcoholic damage.
Action Potentials ; Animals ; Anura ; Ethanol ; pharmacology ; Ringer's Solution ; pharmacology ; Sciatic Nerve ; drug effects