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Biomedical subjects

K Sakamoto

Publications and source records attributed to K Sakamoto.

At least 955 records · Page 53Linked to original sources
PubMed1985

The in vitro and in vivo antitumor effects of pepleomycin alone or in combination with radiation.

Pepleomycin is a derivative of bleomycin, which is less toxic to the host but possesses greater antitumor activity. Experiments are described here in which Chinese hamster V-79 cells in culture and a murine squamous cell carcinoma in vivo have been used to obtain survival curves for pepleomycin alone or in combination with radiation. In both systems the survival curves for pepleomycin alone are biphasic, and this drug proved to be twice as effective as bleomycin. Further, in contrast to bleomycin, which showed simple additivity with radiation, pepleomycin potentiated radiation injury to the tumor cells both in vivo and in vitro. Therefore, pepleomycin may be superior to bleomycin not only in drug therapy but also in combined modality therapy.

Animals↗
PubMed1985

Epstein-Barr virus infections in hairy cell leukemia patients in the presence of complement-dependent neutralizing antibody.

Immune system status was characterized in patients with hairy cell leukemia (HCL) with respect to explaining their chronic or recurrent infections with Epstein-Barr virus. Measures of cellular immune responsiveness for a group of 11 HCL patients were, in general, decreased when expressed as the proportion of tested patients with values less than 2 S.D. below mean values for a group of 17 healthy adults: T-cell enumeration, seven of 13; mitogen responsiveness of phytohemagglutinin, 10 of 11; concanavalin A, 10 of 11; pokeweed mitogen, 10 of 11; B-cell responsiveness by anti-immunoglobulin immunobead stimulation, two of six; responsiveness to streptolysin O antigen, four of seven; mixed-lymphocyte reaction, six of seven; natural killer cell activity, six of eight. Specific immunity to Epstein-Barr virus was measured by complement-independent, antibody-mediated virus neutralization (mean index for HCL patients being 56% of control value) and complement-dependent virus neutralization (98% of control value). We concluded that, in spite of depressed levels of immune responses measured with general, cellular assays, functional levels of complement-dependent virus-neutralizing antibody were present in these HCL patients.

Antibodies, Viral↗
PubMed1985

[Transcatheter hepatic arterial embolization therapy using degradable polylactic acid microspheres].

Transcatheter hepatic arterial embolization therapy (TAE) is an established method for the treatment of hepatocellular carcinoma (HCC). We have developed a new embolus consisting of microspheres with a mean diameter of about 200 microns which are composed of biodegradable polymolecular polylactic and the anti-cancer agent, aclarubicin -HCl, in a ratio of 12% w/w. These microspheres were applied to 28 patients with inoperable HCC using the following method microspheres containing 50 mg of aclarubicin-HCl were injected through a catheter placed in the hepatic artery or one of its branches, 2 or 3 times at intervals of 2 to 4 weeks. The effectiveness was confirmed by decreased levels of serum AFP and regression of the tumor size, and the accumulated survival rate for 6 months was 83.3%.

Aclarubicin↗
PubMed1985

[Effect of fosfomycin on auditory organs and its transfer to cochlear lymph following application of its solution into a middle ear cavity].

Male guinea pigs were given 0.1 ml of 2, 3 or 5% fosfomycin (FOM) ototopical solution once a day for 5 days into a middle ear cavity through artificially perforated ear drum. Kanamycin A (KM) was used at 2% ototopical solution as control drug. Four animals of each group were sacrificed under pentobarbital anesthesia to isolate the cochlea 10 days after the final application. The cochlea was washed with 0.1 M phosphate buffer (pH 7.0), followed by fixing with 2.5% glutaraldehyde and 1% osmic acid. Cochlear specimens were prepared by standard method for scanning electron microscopic observation. The scanning electron microscopic observations revealed some damages in outer and inner hair cells, such as partial deformation or loss of auditory hair in hair cells, but these damages were not correlated to drug treatments. In order to determine the transfer of FOM and KM from middle ear cavity to cochlear lymph in male guinea pigs, the cochlear lymph was collected 0.5, 1, 2 and 4 hours after an application of 0.1 ml of 3 or 5% FOM and 2% KM ototopical solution into a middle ear cavity, followed by estimating content of these antibiotics in the lymph. The results showed the peak concentration in lymph at 1 to 2 hours after an application of 3% FOM was lower than that after 2% KM, but the AUC of 3% FOM was higher than that of 2% KM. The AUC value of FOM was dependent on the applied concentration of FOM. The value of half-life time was about 4.8 hours at FOM and about 2.3 hours at KM.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

The mechanism of tumor growth inhibition by tumor-specific Lyt-1+2-T cells. I. Antitumor effect of Lyt-1+2-T cells depends on the existence of adherent cells.

In the present study we establish an assay system of tumor growth inhibition with the use of a diffusion chamber and investigate the mechanism by which tumor-specific Lyt-1+2-T cells exhibit their inhibiting effect on tumor cell growth. When a diffusion chamber containing X5563 plasmacytoma cells together with normal syngeneic C3H/HeN spleen cells was implanted in the peritoneal cavity of C3H/HeN mice, these tumor cells continued to proliferate at least 7 to 9 days. In contrast, spleen cells from C3H/HeN mice that had acquired X5563-specific immunity by intradermal (i.d.) inoculation of viable tumor cells, followed by surgical resection of the tumor, exhibited an appreciable inhibitory effect on the growth of X5563 tumor cells admixed in the chamber. This antitumor effect was mediated by Lyt-1+2-T cells and was tumor-specific, because the growth of X5563 or another syngeneic MH134 hepatoma cells was inhibited by spleen cells from C3H/HeN mice immunized to the respective tumor cell types. Most important, these tumor-specific Lyt-1+2-T cells lost their antitumor activity by depleting an adherent cell population contained in spleen cells, indicating that adherent cells are required for the Lyt-1+2-T cell-mediated antitumor effect. This was substantiated by the fact that immune spleen cells depleted of adherent cells could regain their tumor-inhibiting effect when normal spleen cells were added back as an adherent cell source, or more directly by adding back a splenic or peritoneal resident adherent cell population. These results indicate that tumor-specific Lyt-1+2-T cells mediate the tumor growth inhibition and that their antitumor effect depends on the coexistence of an adherent cell population.

Animals↗
PubMed1985

[Clinical study on intact gamma-globulin (SM-4300) in surgical severe bacterial infections].

Intact gamma-globulin (SM-4300) was studied for its clinical efficacy in 13 of 23 cases of surgical severe bacterial infections. The drug was administered intravenously either 2.5 g/day for 3 days or 5 g for a day and the results were as follows. Clinical effects of SM-4300 in 13 cases of surgical severe bacterial infections were excellent in 1 case, good in 3, fair in 3 and poor in 6. SM-4300 was effective in all of 5 cases of intraperitoneal abscess. The elevation of serum IgG was observed after the administration of SM-4300 in all cases tested. As to complement, the slight elevation of serum CH50 was observed in the half of cases documented. Clinical side effects were not confirmed in any case. These results suggest that intact gamma-globulin (SM-4300) was effective in combination with antibiotics.

Aged↗
PubMed1985

[Radiobiological consideration for standardization and optimization in radiotherapy on cancers].

It is so important for standardization and optimization in radiotherapy on cancers to estimate accurately target volume for irradiation and radiation injury on normal tissues. It is responsible for radiation diagnosticians to determine target volume, but in order to estimate late injuries on normal tissues radiobiological research is seemed to be useful. Concerning normal tissue damage, it is very difficult to forecast late damages on various sort of normal tissues from the standpoint of radiobiology in course of radiotherapy. To dissolve this problem it is needed to develop new biological model systems and to find new marker to forecast late injuries from acute damages. In this paper it is also discussed for establishment of radiation oncology in Japan.

Humans↗