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Biomedical subjects

T Nakabayashi

Publications and source records attributed to T Nakabayashi.

At least 163 records · Page 9Linked to original sources
PubMed1980

Studies on the effect of bleomycin on Trypanosoma gambiense.

The antibiotic bleomycin inhibits nuclear duplication and causes deformation of the nucleus without any effect on the kinetoplast of Trypanosoma gambiense. Consequently it induces the anucleate form, not the dyskinetoplastic form. Studies showed that in many respects the effect of bleomycin on trypanosomes was very similar to that of neocarzinostatin. Analysis of DNA by CsCl density gradient centrifugation indicated that bleomycin inhibits DNA synthesis in the nucleus but not that in the kinetoplast. Bleomycin also induced excess formation of pellicular microtubules and disorderly arrangement of the axonemal and pellicular microtubules.

Animals↗
PubMed1980

Therapeutic effect of bleomycin on experimental infection of mice with Trypanosoma gambiense and Trypanosoma evansi.

Intraperitoneal injection of 10 mg/Kg bleomycin into mice 24 h after inoculation with Trypanosoma gambiense or Trypanosoma evansi, reduced the incidence of infection 62.1%, and 95.2%, respectively. No parasitemia was not found in these mice. Treatment of mice with parasitemia with 30 mg/Kg of bleomycin decreased the number of parasites within about 5 h and caused complete cure without relapse in 45% and 75% of mice infected with T. gambiense and T. evansi, respectively. Treatment of mice infected with T. gambiense with bleomycin in combination with ethidium bromide was highly effective and resulted in a high incidence of complete cure, even in heavily infected mice. The mode of action of bleomycin and ethidium bromide on trypanosomes in relation to p-rosaniline resistance is discussed.

Animals↗
PubMed1980

A heterophile antigen associated with experimental toxoplasmosis.

The biological characteristics of a heterophile protein (HP) in peritoneal exudate from mice, hamsters, rats, and guinea pigs infected with Toxoplasma gondii were studied by immunofluorescence, immunoelectrophoresis and immunodiffusion techniques using specific antisera raised in rabbits. HP of mice had the highest antigenicity, HP of hamsters and rats had intermediate antigenicity and HP of guinea pigs had the lowest antigenicity. HP was found in normal peritoneal exudates from mice, hamsters and rats inoculated with paraffin oil instead of T. gondii and in normal guinea pig serum. HP was detected by the fluorescent antibody technique on the surface of T. gondii in peritoneal exudates of mice, but not on mouse peritoneal cells, and by the indirect fluorescent antibody technique on L cells infected with T. gondii and on free Toxoplasma derived from them, but not on uninfected L cells. T. gondii could make host cells produce HP to cover its surface for protection. The relation between HP from host cells and T. gondii is discussed.

Animals↗
PubMed1980

Immunological analyses of antigens associated with experimental toxoplasmosis.

By immunoelectrophoresis of periotoneal exudates and toxoplasma cell antigens from mice and hamsters infected with Toxoplasma gondii, using their corresponding rabbit antisera absorbed with serum of uninfected animals, eleven precipitating antigens were distinguished and named No. 1--11 in order of increasing electrophoretic mobility. Monospecific rabbit antisera against two of these antigens (antigen No. 1 and 11) were prepared by immunization with antigen purified by zone electrophoresis, and were used for immunochemical analyses: the component with higher mobility on immunoelectrophoresis, antigen No. 11, was detectable only in association with toxoplasma infection of mice, hamsters, rats and guinea pigs. Antigen No. 11 was also detectable as a single major antigen in the medium of cultures of L cells infected with T. gondii, RH strain. In contrast, antigen No. 1 was detectable in uninfected mice in peritoneal exudates, and homogenates of thymus, liver and spleen, but not of brain or lymphocytes. In the latex agglutination test (LAT) for toxoplasmosis, anti-No. 1 serum gave a positive reaction, but anti-No. 11 gave a negative one. In 31 anti-toxoplasmosis sera examined, there was no correlation between the number of precipitating antibodies detectable by immunoelectrophoresis and the LAT titer.

Animals↗
PubMed1979

An isoelectric focusing study of acid phosphohydrolases in liver lysosomes of higher vertebrates.

1. The multiple forms of acid phosphohydrolases in liver lysosomes of Sus scrofa domesticus and Gallus gallus domesticus were studied by use of isoelectric focusing. 2. Acid phosphatase was resolved into two forms in G. gallus domesticus and three forms in S. scrofa domesticus. Especially, two forms of G. gallus domesticus were different from each other in their enzymatic properties. 3. The pI values of acid ATPase agreed with those of acid phosphodiesterase in G. gallus domesticus. According to the data on activity ratios, however, these enzymes seemed not to be identical. 4. Except acid deoxyribonuclease, extraction by Triton X-100 of lysosomes increased the proportions of acidic forms of these enzymes. In particular, a new form of acid ribonuclease with pI 4.5 or 4.9 appeared in both cases of G. gallus domesticus and S. scrofa domesticus.

Acid Phosphatase↗
PubMed1979

Different appearance of parasitized erythrocytes in blood between normal and toxoplasma-infected rats after infection of Plasmodium berghei.

When normal rats were infected with Plasmodium berghei (Pb), both IgG and IgM immunofluorescent antibody titers were found to rise in the 1st week with increase of parasitaemia. After reinoculation of P. berghei into Pb-immune rats, IgG titer was further increased remarkably, although no parasitaemia was observed. No elevation of IgM titer was found. In rats infected with Toxoplasma gondii (Tg), IgG and IgM antibody activities were demonstrated in the 1st to the 3rd week postinfection but only IgG titer was maintained to the 16th week. The challenge with T. gondii to Tg-immune rats stimulated the further increase in IgG titer but not in IgM. When Tg-immune rats were infected with P. berghei, little or no parasitaemia appeared. In infection of P. berghei in Tg-immune rats which were treated with anti-rat thymocyte serum (ATS) beforehand, highly increased parasitaemia was usually found in the rats as compared with that in ATS non-treated rats. Pb-immune macrophages were more effective in phagocytosis of Pb-parasitized erythrocytes in vitro than normal or Tg-immune macrophages. When Pb-parasitized erythrocytes were preincubated with fresh Pb-immune serum, the phagocytosis rate of macrophages was clearly heightened. It was observed that the phagocytic activity of normal macrophages to Pb-parasitized erythrocytes was stimulated by addition of the supernatant (lymphokines) taken from the incubation of Tg-immune lymphocytes with Tg-antigen or Pb-antigen.

Animals↗
PubMed1979

Electronmicroscopic observations on lysis of Trypanosoma cruzi epimastigote by normal rabbit serum.

The lytic effects of serum from a non-immunized rabbit on epimastigotes of Trypanosome cruzi were studied by electronmicroscopy. The first detectable change was the appearance of a fuzzy deposit over the whole surface of the epimastigote. Soon after this, pellicular microtubules disappeared without change of axonemal microtubules. Circular lesions were observed by negative staining, corresponding to the lesion of antibody-mediated lysis caused by complement.

Animals↗
PubMed1979

Studies on the effects of vinblastine and colchicine on Trypanosoma gambiense.

Vinblastine and colchicine induce the anucleate form of Trypanosoma gambiense. Light microscopic studies indicated that the anucleate form was not always produced as a result of inhibition of nuclear duplication, but was formed as a result of delay or inhibition of separation of the two nuclei after completion of nuclear division. Studies showed that vinblastine and colchicine caused disorder in arrangement of axonemal microtubules of the extracellular flagella and increased formation of both protofilaments and the axoneme composed of protofilaments in trypanosomes. Moreover, treatment with colchicine resulted in disintegration of previously existing pellicular microtubules and formation of cytoplasmic projections that appeared as protrusions from a small part of the surface membrane.

Animals↗
PubMed1978

An isoelectric focusing study of acid phosphohydrolases in rat liver lysosomes.

The differentiation of rat liver lysosomal acid phosphatase, acid ATPase, acid phosphodiesterase, acid ribonuclease, and acid deoxyribonuclease was studied by isoelectric focusing. To prevent autolytic digestion, inhibitors of cathepsins and neuraminidase were used. The proportion of acidic forms of acid phosphatase, acid ATPase and acid phosphodiesterase was increased by the use of extraction medium containing 0.05% Triton X-100. To investigate the identity of acid ATPase and acid phosphodiesterase, the relative activities among the multiple forms of these enzymes, the acid phosphodiesterase/acid ATPase ratio at each activity peak, and the degree of enzyme inhibition by p-chloromercuriphenyl sulfonic acid were estimated. The results suggest that acid ATPase is not identical with acid phosphodiesterase. With extraction medium free of Triton X-100, acid ribonuclease appeared in two forms. However, in addition to these forms, a new form of this enzyme with a more acidic pI (4.22) emerged when extraction medium containing 0.05% Triton X-100 was used. The major peak of acid deoxyribonuclease with pI=8.40-9.39 was obtained regardless of the extracting method.

Acid Phosphatase↗
PubMed1978

Effect of neocarzinostatin on the nucleus, kinetoplast and microtubules of Trypanosoma gambiense and Trypanosoma evansi.

The antibiotic neocarzinostatin (NCS) induces the anucleate form, not the dyskinetoplastic form, of Trypanosoma gambiense and Trypanosoma evansi. Light and electron microscopic studies indicated that production of the anucleate form is due to delay or inhibition of nuclear division. Excess pellicular microtubules are formed after treatment of trypanosomes with NCS, suggesting that in trypanosomes the microtubules replicate by induction, not by division. NCS also causes deformation of the axonemal and spindle microtubules. The K clone of T. evansi is more sensitive than the AK clone to the effects of NCS in inhibiting nuclear division and inducing the anucleate form.

Animals↗
PubMed1976

Frequency-dependency of pulmonary compliance and its relation to airway conductance.

Dynamic compliance was determined in patients with 6 chronic obstructive lung diseases, 2 sarcoidosis and in 4 control healthy subjects at several breathing frequencies ranging between 0.2 and 1.3 Hz. The compliance exhibited an apparent fall with the increase in frequency of the patients, while it remained unaltered in the controls. A significant correlation was found between the frequency-dependency of compliance and the airway conductance determined plethysmographically. A similar relationship was also found in previous data appearing in the literature. Mathematical simulation based on the time constant theory revealed that the above correlation might be expected when airway obstruction occurred inhomogeneously in the peripheral region, of the lungs leaving the central airways intact.

Adult↗