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Biomedical subjects

Y Irie

Publications and source records attributed to Y Irie.

At least 127 records · Page 7Linked to original sources
PubMed1987

Degenerative changes in the reproductive organs of female schistosomes during maintenance in vitro.

Degenerative alteration of the reproductive organs of female schistosomes in correlation with the change in egg-laying rate of schistosome pairs in vitro was studied by electron microscopy. The production of normal eggs by adult S. japonicum pairs decreased after 4 days in vitro followed by an increase of abnormal egg laying up to day 8. In S. mansoni, the yield of both normal and abnormal eggs decreased gradually from the start of maintenance in vitro in spite of a much higher pairing rate than in S. japonicum. The vitelline gland of 14-day in vitro-maintained S. japonicum stained with Fast red B, while that of S. mansoni did not. The ovary of both species exhibited regressive features after 14 days of maintenance in vitro. Ultrastructural examination showed that the vitelline cells and oocytes of S. japonicum and S. mansoni had already lost their structural integrity after 2 days in vitro and continued to exhibit signs of structural degeneration throughout the 14-day in vitro maintenance period. The regressive changes in reproductive potential of female S. mansoni maintained in vitro for 4 days could be reversed by surgically implanting the parasites into mouse mesenteric veins.

Animals↗
PubMed1986

The killing effect of subclasses of mouse IgG antibodies on schistosomula of Schistosoma japonicum.

The killing effect of IgG antibodies in sera from S. japonicum infected mice on schistosomula of S. japonicum was studied in vitro in the presence of complement. Immune mouse sera were fractionated over Protein A-Sepharose and IgG1, IgG2a, IgG2b and IgG3 were purified by affinity chromatography. The killing activity of each subclass of IgG antibodies against schistosomula was observed only in the presence of complement. The activity of IgG1 was higher than that of the other subclasses of IgG. In combination of the two or three subclasses of IgG, the additive mortality rate was given in all combinations of each subclass of IgG. These results support the view that the combination of various subclasses of IgG antibodies potentiates the resultant lethal effect on schistosomula.

Animals↗
PubMed1984

[Splenic cyst].

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Aged↗
PubMed1984

Comparison of protein composition between schistosomula of Schistosoma japonicum and S. mansoni.

SDS-PAGE analysis revealed that the protein composition of mechanically transformed schistosomula (ms) of a Japanese strain of Schistosoma japonicum was essentially similar to that of a Philippine strain of S. japonicum. However, the protein components of S. mansoni ms were remarkably different from those of S. japonicum. Specific proteins of Mr 60-65 and 30 kDa were found in ms of S. japonicum and S. mansoni, respectively. In skin-penetrated schistosomula (ss) of the two species, a common protein of 67 kDa was detected. Using two-dimensional electrophoresis, strain-specific polypeptides (9 in a Japanese and 11 in a Philippine strain) were identified in ms of S. japonicum. Mechanically transformed and skin-penetrated schistosomula of S. japonicum (Japanese) had, respectively, 7 and 10 specific proteins. Four and 1 specific polypeptides were also detected in two-dimensional profiles of ms and ss of S. mansoni, respectively.

Animals↗
PubMed1983

Reproductive ultrastructure of adult Schistosoma mansoni grown in vitro.

The reproductive organs of paired S. mansoni adults cultured from cercariae were examined by transmission electron microscopy to assess their development. In males, many mature sperm, closely associated with the sustentacular cells, were produced in the testes. In females, although the vitelline gland had fewer lobules than were found in worms from animal infections, the cytoplasm of many vitelline cells contained abundant vitelline and lipid droplets. The structure of the Mehlis' gland, ootype, and uterus resembled that of in vivo adult females. However, in the ovary, the oocytes tended to degenerate, and within the ootype and uterus the oocytes were not embedded within egglike material. We conclude that a dysfunction of ovarian development is the primary reason for the reproductive failure of schistosome pairs grown in vitro under our experimental conditions.

Animals↗
PubMed1983

Toxicological studies on bestatin. I. Acute toxicity test in mice, rats and dogs.

Studies on acute toxicities of bestatin (NK421) were carried out in both sexes of mice and rats, and male dogs. NK421 was administered subcutaneously, intraperitoneally and orally in mice and rats, and orally in dogs respectively. Mice and rats were observed for 14 days after treatment and LD50 values were calculated by the probit method. NK421 showed very low toxicity and no death occurred in any species following the oral administration of the maximum dose capable of dosing such as 4 g/kg for mice, 2 g/kg for rats and 1.2 g/kg for dog. General toxic signs seen in mice and rats following subcutaneous and intraperitonial injections were as follows; depression, suppressed movement, piloerection, inhibition of spontaneous movement, anorexia and emaciation. Death occurred within 5 days after administration. The toxic target organs of NK421 were found to be kidney, lymphoid tissue and liver based on histopathological examination of dead animals.

Administration, Oral↗
PubMed1983

Toxicological studies on bestatin. II. Subacute toxicity test and recovery study in beagle dogs.

Subacute toxicity and its recovery of bestatin (NK421) was studied on both sexes of 34 Beagle dogs. At dose levels of 600, 240, 96 and 38.4 mg/kg, NK421 was administered orally to dogs for 90 successive days. The control group was treated orally with 2 g/dog of corn starch. Each group was constituted of 3 males and 3 females, and 2 males and 2 females were added to the 240 mg/kg group for the recovery test for 35 days. As general symptoms, loss of appetite, vomiting, abnormal feces (loose stool, diarrhea, mucous stool), eye mucus, decoloration of the visible mucous membrance and unkempt fur were observed slightly and almost dose-dependently in the group dosed with more than 96 mg/kg. Body weight decreased with the passage of time in the 600 and 240 mg/kg groups, but no death appeared in any group. In correlation with general signs, slight anemia was seen hematologically, and the increased alkaline phosphatase activity and the decreased albumin ratio in serum protein fraction were observed biochemically. The slight abnormal findings of bone marrow, spleen and liver were also demonstrated histopathologically. All the above findings disappeared during the recovery period. The maximum non-toxic dose of NK421 in this study is estimated to be 38.4 mg/kg in dogs.

Animals↗
PubMed1983

Toxicological studies on bestatin. III. Chronic toxicity test and recovery study in beagle dogs.

Chronic toxicity and its recovery of bestatin (NK421) was studied in both sexes of 28 Beagle dogs. At dose levels of 96, 38.4 and 15.4 mg/kg, NK421 was administered orally to dogs for 540 successive days. Control dogs were treated orally with 2 g/dog of corn starch. Each group consisted of 3 males and 3 females, and 2 males and 2 females were added to the 38.4 mg/kg group for a recovery test of 35 days. As general signs, anorexia, abnormal feces (loose stool, diarrhea, mucous stool), loss of activity, loss of lustre in fur, decoloration of the visible mucosa and emaciation were transiently observed in a early stage in 1 male and 1 female of the 96 mg/kg group. In correlation with these signs, slight anemia appeared hematologically, and the increased alkaline phosphatase activity and the decreased albumin ratio in serum protein fractions were observed biochemically. Except for the slight abnormal findings observed in the liver of the above 2 dogs, no significant changes were histopathologically noticed in any organ of all the dogs examined. The maximum non-toxic dose of NK421 in this study is estimated to be 38.4 mg/kg in dogs.

Animals↗
PubMed1982

Resistance of mice to secondary infection with Schistosoma japonicum, with special reference to neutrophil enriched response to schistosomula in the skin of immune mice.

The lung recovery assay for schistosomula has been used as a rapid method for measuring acquired resistance to Schistosoma mansoni infection in challenged animals. This assay method was successfully utilized in the present study with S. japonicum in mice. Assay of resistance to reinfection with the lung recovery technique and with the conventional perfusion method demonstrated that a considerable level of resistance developed in mice which had received the primary infection of 30 S. japonicum cercariae 8 weeks prior challenge infection. In a histological study of this period, as early as 4 hours after challenge exposure there was already a dense accumulation of cells around a small proportion of schistosomula in the immune mouse skin. Light and electron microscopy revealed that the adherent cells were mainly neutrophils. There was a more increase in the cellular reaction around the schistosomula in the skin 24 hours after challenge and the cells of this reaction were still predominantly neutrophils with a few eosinophils. A small proportion of these entrapped schistosomula showed structural damage. In contrast, schistosomula in the lungs of immune mice were essentially without cellular association. It appears from our work that the adherence of neutrophils to schistosomula in immune mouse skin contributes to a reduction in the number of worms which subsequently develop.

Animals↗
PubMed1982

Morphological alterations of Schistosoma japonicum associated with the administration of amoscanate.

Morphological alterations of Schistosoma japonicum induced by the administration of a curative dose (20 mg/kg) of the schistosomicide, amoscanate (4-isothiocyanate-4'-nitrodiphenylamine, CGP4540), were studied. Worms from amoscanate-treated ddY mice exhibited remarkable changes on the surface of male and female worms, as well as in the vitelline cells of females. Various types of lesions, such as swelling and ballooning of the tegument, constriction of folds and channels, disruption of sensory receptors and exfoliation of surface layers, were prominent in many areas of the worm body. These alterations were variable in different worms recovered from the same host. The extent of the lesions was not dependent on the period of recovery after treatment.

Aniline Compounds↗
PubMed1981

Schistosoma japonicum: ultrastructural changes in the tegument during cercaria-schistosomulum transformation.

The tegumental changes of Schistosoma japonicum cercaria were initiated when introduced into NCTC 109 containing antibiotics for axenizing. In some regions the tegument was covered with a penta- or heptalaminate membrane, and the surface coat changed into an electron-dense, amorphous material. Large vacuoles limited by a multilaminate membrane were evident in the tegumental cytoplasm, and some appeared to join or open to the tegument. After 4 h incubation in NCTC 109 containing 50% fresh rabbit serum, the outer tegumental membrane of schistosomulum became heptalaminate. The amorphous material was still present on the surface of the tegument. Within 72 h the tegument was covered with a heptalaminate membrane over a greater part of the body, and the amorphous material was very reduced. Large vacuoles in the tegument disappeared and tegumental folds developed in some regions. No amorphous material existed on the surface of 10-day schistosomulum and the outer membrane of the tegument was heptalaminate in almost all regions of the body.

Animals↗