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Biomedical subjects

H Kitani

Publications and source records attributed to H Kitani.

90 records · Page 5Linked to original sources
PubMed1984

Effect of PSK on interferon production in tumor-bearing mice.

The effect of PSK on the depressed interferon (IF) production in tumor-bearing mice was studied. In tumor-bearing mice, in vitro IF production by spleen cells treated with polyinosinic-polycytidylic acid (poly I:C) was remarkably inhibited. However, these inhibitions were prevented by the intraperitoneal (ip) administration of PSK. Mice were inoculated intravenously (iv) with poly I:C-treated spleen cells, administered with PSK ip at 3 days after the tumor inoculation. When PSK was not given, poly I:C-treated spleen cells did not show an inhibitory effect on tumor growth. In mice given PSK ip, poly I:C-treated spleen cells exerted slightly inhibiting effects on tumor growth. These results suggest that PSK prevented such a modulation in tumor-bearing mice.

Animals↗
PubMed1984

[Depression of protective mechanisms against ectromelia virus infection in tumor-bearing mice and its prevention by PSK].

Effector mechanisms responsible for protection against ectromelia virus (EMV) including antiviral activity of non-immune macrophages, cytotoxic T cells, antiviral antibody, delayed footpad reaction to viral antigen and interferon induction after viral infection were depressed in BALB/c mice bearing syngeneic Meth A tumors. The degree of viral growth correlated well with the depression of delayed footpad reaction, antibody production and interferon induction. But a control level of these elements could be obtained by pretreatment of tumor-bearing mice, with PSK Cytotoxic activity may not be the principal effector, since cytotoxicity was induced in both normal and tumor-bearing mice to almost the same extent but an explosive viral growth was observed only in the latter. These results suggest that PSK was responsible for restoring the depressed antiviral protective immunity to normal levels in tumor-bearing animals.

Adjuvants, Immunologic↗
PubMed1984

Relationship between bactericidal and phagocytic activities of peritoneal macrophages induced by irritants.

Cellular accumulation to the peritoneal cavity and modification of various functions of peritoneal macrophages were observed in mice injected intraperitoneally (ip) with thioglycollate medium (TG), liquid paraffin, proteose peptone and Corynebacterium parvum. The cellular composition of peritoneal exudates at 4 days after injection of irritants was almost the same in all the groups and the proportion of macrophages was increased approximately 4 times more than nontreated controls. The ability to kill Listeria monocytogenes and to generate chemiluminescence (CL) were augmented strongly in C. parvum-induced macrophages, while depressed in TG-induced macrophages. The activities of liquid paraffin- or proteose peptone-induced macrophages were almost the same as those in nontreated controls. However, the ability to phagocytose native sheep erythrocytes was greatly augmented both in C. parvum- and TG-induced macrophages. There is thus a discrepancy between bactericidal activity and phagocytic activity among macrophages induced with various irritants.

Animals↗
PubMed1983

Metabolism of 4-hydroxyaminoquinoline-1-oxide and its binding to DNA in chick embryos.

The metabolic pathway of 4-hydroxyaminoquinoline-1-oxide (4HAQO) and its binding to DNA was studied in 2-day chick embryos administered [G-3H]4HAQO in a shell-less culture. The 4HAQO rapidly metabolized into non-carcinogenic compounds and 1 h after administration only very small amounts of free 4HAQO could be detected in the embryo cells. The amount of DNA-bound 4HAQO in the embryo cells reached a maximum 2 h after administration, then began to decrease. The maximum extent (mu mol/mol P of nucleotide) was 18.2, equivalent to 1 molecule of 4HAQO-purine adducts per 2.8 X 10(4) base pairs of DNA. It was possible to detect removal of 4HAQO-purine adducts from DNA in chick embryo cells in a shell-less culture. A dose-response relationship for the killing effect of 4HAQO on 2-day embryos was observed in the range of 0.24-24 nmol 4HAQO per embryo. The practicality of the present method of administration of 4HAQO for 'flash administration' of compounds to chick embryo and the advantages of the shell-less culture method which provides access for biochemical and developmental studies of chick embryos were also discussed.

4-Hydroxyaminoquinoline-1-oxide↗
PubMed1983

Mechanism of protection during the early phase of a generalized viral infection. I. Contribution of phagocytes to protection against ectromelia virus.

Effects of carrageenan and gamma-irradiation on virus titre in the liver were observed after intravenous inoculation of 8 X 10(3) p.f.u. of ectromelia virus which was not lethal for untreated mice. Trapping of virus by the liver within 30 min and an initial transient reduction in titre by day 1 were not affected by gamma-irradiation but were inhibited by pretreatment with carrageenan. An increase from day 1 to day 3 was not affected by gamma-irradiation but was augmented by pretreatment with carrageenan. Therefore, protection within 3 days may depend principally upon carrageenan-sensitive and irradiation-resistant cells, namely, fixed macrophages. Elimination of virus from day 4 to day 7 depended upon cell-mediated immunity. When carrageenan was given 3 days after virus inoculation, the titre of virus increased progressively from day 4 ultimately to kill the hosts. The cytotoxic activity of spleen cells against infected target cells was raised in carrageenan-treated mice as well as in untreated mice. Immune elimination of virus may be mediated by a mechanism requiring the cooperation of sensitized T lymphocytes and blood monocytes.

Animals↗
PubMed1983

Augmented delayed footpad reaction in thymus cell-depleted mice induced by cholera toxoid.

One hundred microgram of cholera toxoid was injected intravenously into DDD and AKR mice and its effects on lymphoid tissues and immune responses against sheep erythrocytes (SRBC) were examined at various times after the injection. (1) A remarkable reduction of thymus cells was revealed from day 1 to 7 and from day 1 to 4 in DDD and AKR mice, respectively. (2) Cholera toxoid exhibited only slight effects on the numbers of spleen cells and peripheral blood leukocytes in both strains. (3) Delayed footpad reactions to SRBC were augmented by a pretreatment with cholera toxoid 4 or 7 days before immunization in both strains. The delayed reactions were not suppressed in the presence of a prominent antibody production and were accompanied by positive macrophage migration inhibition. (4) Antibody production against SRBC, especially of IgG class, was facilitated, when cholera toxoid was given 7 days before the immunization through the footpad in DDD mice. On the other hand, antibody production was suppressed irrespective of immunizing routes and mouse strains, when cholera toxoid was given 1 day before immunization.

Animals↗
PubMedDate not supplied

Serum-free culture of adult chicken hepatocytes; morphological and biochemical characterisation.

The morphological and biochemical characterisation of adult chicken hepatocytes in a serum-free culture are described. When cultured in positively charged plastic dishes, chicken hepatocytes formed a monolayer cell sheet. The monolayer morphology of these chicken hepatocytes was quite distinct from the spheroid shape of rat hepatocytes cultured under similar conditions. Electron microscopy showed that the cytoplasmic organelles of chicken hepatocytes were well preserved in vitro. Two-dimensional gel electrophoresis showed that the chicken hepatocytes secreted liver-specific proteins. Several enzymes of glucose-6-phosphatase, cytochrome P-450 or glutathione S-transferase, involved in metabolic and biotransformation pathways in the liver, were retained in the chicken hepatocytes in a serum free condition. These findings suggest that the primary culture of adult chicken hepatocytes with a serum-free culture system could be useful to study the hepatic metabolic pathway in the chicken and its response to various chemicals.

Albumins↗
PubMedDate not supplied

Efficiency of neural differentiation of mouse P19 embryonal carcinoma cells is dependent on the seeding density.

Serum-free culture conditions for retinoic acid-induced neural differentiation of mouse P19 embryonal carcinoma cells were determined for future ex vivo retroviral gene transfer and brain transplantation studies. Neural differentiation of P19 cells was dependent on the seeding densities, and both neurons and astroglia differentiated efficiently at high seeding densities (2 x 10(4) and 5 x 10(4) cells/cm2) but not at low seeding density (1 x 10(4) cells/cm2). In addition, P19 cells cultured at 5 x 10(4) cells/cm2 showed neural differentiated whether or not they were infected with Friend leukemia virus FrC6-V, which inhibited neural differentiation at 2 x 10(4) cells/cm2. These results indicate that FrC6-V-infected P19 embryonal carcinoma cells should be seeded at high density to achieve efficient neural differentiation in vitro for ex vivo gene transfer with a FrC6-V-derived retroviral vector system.

Animals↗
PubMedDate not supplied

Release of heparin-like substance and histamine from basophilic leucocytes separated by counterflow centrifugation elutriation.

Separation of basophilic granulocytes from peripheral blood was carried out by counterflow centrifugation elutriation using a JE-6B roter. The release of histamine and heparin-like substance from basophilic leucocytes was estimated in healthy and asthmatic subjects. 1. The number of basophils was maximal (0.74 x 10(5] at a flow rate of 4.5 ml/min, and the purity reached a peak (11.8 +/- 2.0%) at a flow rate of 9 ml/min. 2. The content of histamine paralleled the number of basophils in each fraction. 3. The release mechanism of histamine induced by anti-IgE was similar to that of the heparin-like substance. 4. The release of histamine and the heparin-like substance was significantly higher in atopic asthmatics than in non-atopic cases.

Adolescent↗