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Biomedical subjects

K Fujisaki

Publications and source records attributed to K Fujisaki.

At least 127 records · Page 7Linked to original sources

Isolation of Theileria sergenti piroplasms from infected erythrocytes and development of an enzyme-linked immunosorbent assay for serodiagnosis of T sergenti infections.

A method of obtaining a pure suspension of Theileria sergenti piroplasms from infected bovine erythrocytes was developed and the resulting parasites used as antigen in an enzyme-linked immunosorbent assay (ELISA). Piroplasms were freed from infected erythrocytes using the nitrogen cavitation technique and then separated from unbroken erythrocytes by centrifugation at 670 gmax. The parasites in the supernatant were then sedimented by centrifugation at 2700 gmax and the purified fraction examined by electron microscopy. This examination showed that the isolated piroplasms were morphologically intact and that there were few contaminants. SDS-PAGE and spectrophotometric analysis showed that this fraction contained little erythrocyte component. The piroplasms thus obtained were sonicated and treated with Triton X-100 then used for ELISA antigen. The ELISA values had a high correlation with titres obtained using the indirect fluorescent antibody test on sera from cattle infected with T sergenti.

Animals↗

A life-cycle stage-specific antigen of Theileria parva recognized by anti-macroschizont monoclonal antibodies.

Four monoclonal antibodies, raised against macroschizonts of Theileria parva, were studied to characterize their antigen binding specificity. The indirect fluorescent antibody test showed that the antigen(s) recognized were present in the macroschizont stage of the parasite life-cycle but not in piroplasm, kinete or sporozoite stages. Immunoblot analysis of macroschizont stage antigens suggested that all four antibodies recognized the same antigen. This was a molecule which varied in molecular mass between different parasite stocks, ranging from 68,000 to 95,000 Da. The antigen was localized by immunoelectron microscopy to the surface of the intracellular macroschizonts.

Animals↗

Choanal bleeding due to nasopharyngitis.

Twenty-two patients with bleeding from the nasopharynx which due to secondary changes in acute nasopharyngitis were treated at the Fujisaki Hospital. The titers of IgG, IgM and IgA of the viral capsid antigen (VCA), IgG and IgA of the early antigen (EA), and EB nuclear antigen (EBNA) were measured. There was no correlation between season of coryza or changes in season and the onset of nasopharyngitis, except for a slightly greater occurrence during mid summer and mid winter. One of three patients with severe bleeding, underwent posterior nasal packing using a rolled 10 X 10 cm gauze sponge. The majority of cases of bleeding from the nasopharynx were most satisfactorily treated by administration of the ranitidine hydrochloride (Zantac) of a selective antagonist for the H2-receptor of histamine.

Adult↗

Tick antigens recognized by serum from a guinea pig resistant to infestation with the tick Rhipicephalus appendiculatus.

Immune resistance to infestation by an ixodid tick, Rhipicephalus appendiculatus, the vector of the cattle disease East Coast Fever, was induced in a guinea pig by repeated tick infestation. This resistance is expressed as the ability of the host to interfere with tick feeding. Resistance to ixodid tick feeding is an acquired response mediated by host antibody. We report the use of antibodies from a resistant host animal, in immunoblotting, to characterize the tick antigens recognized. The major tick antigens identified had molecular weights of 120,000, 94,000, 88,000, 77,000, 58,000, 46,000, 35,000, 31,000, 28,000, 25,000, 20,000 and 16,000. Most of these antigens were found in tick salivary glands. The presence and concentration of many tick salivary antigens appeared to vary with relation to the tick feeding cycle. Many of the antigens present in salivary glands were also detected in tick cement. Tick gut extract, although a poorer source of antigens, contained more of the 31,000 dalton antigen than salivary glands. Larval and nymphal tick extract lacked many of the antigens present in adult ticks. The data suggest that tick resistance is a complex phenomenon probably elicited by several different tick antigens.

Animals↗

The presence of Theileria sergenti in Haemaphysalis longicornis overwintering in pasture in Japan.

Unfed Haemaphysalis longicornis ticks were collected from the soil of pasture during the winter and their salivary glands were examined by the methyl green pyronin staining method in order to detect overwintering of Theileria sergenti, the causative agent of bovine theileriosis in Japan. A transmission experiment was carried out using these ticks applied to a splenectomized calf. The protozoa which appeared in the peripheral blood were identified parasitologically and seroimmunologically as T. sergenti. The results suggested that T. sergenti in Japan might overwinter in H. longicornis which moulted after repletion on infected cattle in the autumn and hid in the soil during the winter. Moreover, it seemed possible that T. sergenti might develop to the infective stage in H. longicornis during the overwintering period.

Animals↗

Glucagon degradation in fraction of big plasma glucagon in rats treated with carbon tetrachloride.

When whole plasma obtained from rats given carbon tetrachloride was applied to a column of Bio Gel P-30, P-150 or P-300, a large molecular form of immunoreactive glucagon (IRG), so called "big plasma glucagon" (BPG), was eluted in the void volume. Glucagon degrading activity, measured under the same conditions as for radioimmunoassay of IRG, was eluted in parallel with IRG. Since standard assay mixture containing aprotinin was used for the measurement of IRG, this degradation of glucagon might be due to an enzyme(s) other than serine proteinases. p-Hydroxymercuribenzoate depressed glucagon degradation and IRG in the BPG fractions to 20% and 30% of the control values, respectively. Other inhibitors of thiol proteinases, such as N-ethylmaleimide and leupeptin, also decreased the values for both glucagon degradation and IRG to a similar extent. However, phenylmethylsulfonyl fluoride and pepstatin had little or no effect on these values. On filtration of plasma from carbon tetrachloride-treated rats on a column of Bio Gel A-1.5m, IRG peaks between 600k and 1,200k daltons were obtained and glucagon degrading activity was again eluted with IRG. When p-chloromercuriphenyl sulfonate and N-ethylmaleimide were added to the elution buffer and assay mixtures, the glucagon degrading activity was almost completely inhibited and the values for IRG between 600k and 1,200k daltons were decreased to less than 10% of those of the control. These results indicate that more than 90% of the IRG in the fractions of BPG obtained from carbon tetrachloride-treated rats could be accounted for entirely by the degradation of immunoreactive 125I-glucagon by plasma proteinases, probably thiol proteinases. Thus we conclude that some proteinases are still active in the radioimmunoassay system of glucagon which is widely used at present, and lead apparently higher glucagon values owing to degradation of 125I-glucagon.

Animals↗

Direct immunofluorescent staining of Leucocytozoon caulleryi of different developmental stages.

Direct immunofluorescence was first used successfully for the staining of Leucocytozoon caulleryi of different developmental stages, such as the 2nd generation schizont and merozoite, gametocyte, zygote, ookinete, and sporozoite. Fluorescent antibody of IgG nature prepared from sera of chickens over a period from the 21st to the 100th day after sporozoite inoculation was used in this experiment. The cross reactivity on different developmental stages of L. caulleryi in the direct fluorescent antibody test suggested that antigens common to different developmental stages, or shared antigens, might exist, as well as specific antigens so far well-known. The fluorescent intensity of oocyst sporozoite, and schizont contents was apparently lower than that of any other stage. This evidence might be elucidated by the antigenic incompletion.

Animals↗

Hepatic gluconeogenic key enzymes in patients with hepatic cancer.

Key enzymes of gluconeogenesis in the liver, phosphoenolpyruvate carboxykinase [EC 4.1.1.32] and glucose-6-phosphatase [EC 3.1.3.9], were studied in patients with primary or metastatic hepatic cancer. Liver specimens for enzyme assay were obtained by necropsy performed within four hours after death. It was confirmed that both enzyme activities in rat liver preserved at 4 degrees C remained unchanged within nine hours after the removal of the tissue. Activities of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase decreased to below ten per cent of the control in neoplastic liver tissue of patients with hepatocellular carcinoma accompanied with liver cirrhosis. These two enzyme activities in cirrhotic tissue of patients with hepatocellular carcinoma were lower than those in patients merely with cirrhosis. In patients with metastatic hepatic cancer both two enzyme activities further decreased and were scarcely detected not only in neoplastic tissue but also in non-neoplastic tissue. These results show that hepatic gluconeogenesis markedly decreases in patients with primary or metastatic hepatic cancer. The biochemical analysis of the blood in hepatic cancer, decreased in blood glucose and release in immunoreactive glucagon, also suggested the suppression of gluconeogenesis.

Adult↗