@article{oai:nagasaki-u.repo.nii.ac.jp:00024876,
 author = {嶋田, 雅暁},
 issue = {1},
 journal = {熱帯医学 Tropical medicine},
 month = {Mar},
 note = {Hatchability of Schistosoma haematobium ova was studied. Urine samples containing the ova were collected from the patients in Taveta area in Kenya, East Africa during the period between August 1975 and December 1976. Urinalysis revealed the specific gravity varying from 1.001 to 1.030, pH from 5 to 8 and most of the specimens showed slight or moderate haematuria and proteinuria. Occasionally, spontaneously emerged miracidia and empty egg shells were found even in fresh urine. The rate of hatched eggs reached up to 60 to 95 per cent of total eggs if the specific gravity of urine was lower than 1.011. Most of miracidia emerged from egg shells seemed to be less active, suggesting the decrease of infecting ability to the snail host. Hatchability was tested on the urine samples showing specific gravity higher than 1.010, where little spontaneous hatching was observed. The urine was diluted by two fold dilution method. It was recognized that hatched eggs began to appear in diluted urine having specific gravity lower than 1.006 and the number of hatched eggs increased as the urine was diluted more. But hatching in the diluted urine did not occur so frequently as those in nondiluted urine with the same specific gravity. When the intact S. haematobium ova were dropped into water, they started hatching within 10 minutes and almost all eggs completed the hatching process within 30 minutes. The hatching rate provided a normal distribution with a peak at 19 minutes after exposure. There was a great difference of hatching rates at two hours after exposure among the samples, which varied from 43 to 100 per cent. The difference seems to depend on the specific gravity of urine specimen. The hatching rates of ova from low specific gravity urine were diminished. There was no definite effect of pH of urine and RBC or protein in the urine on the hatchability. Hatching occured equally well in light and in darkness but delayed in the latter, suggesting light plays minor role in the hatching process. Eggs stored in urine at room temperature lost thier hatchability within 48 to 72 hours. These results apparently revealed the fact that the urine specific gravity, which is directly propotional to the osmorality, appeared to have a definite effect on the hatching rate of ova., 熱帯医学 Tropical medicine 21(1). p29-36, 1979},
 pages = {29--36},
 title = {ビルハルツ住血吸虫卵の孵化に関する二,三の観察},
 volume = {21},
 year = {1979}
}