Acta Medica Okayama 40巻 2号

The serum ceruloplasmin concentration was determined in cancer patients before and after radiotherapy, and after relapse of cancer, The ceruloplasmin concentration in patients who responded to therapy, decreased to the range of normal controls. In patients who did not respond to treatment, the ceruloplasmin concentration was more or less elevated. In patients with relapse of cancer, the ceruloplasmin concentration was higher than before treatment.

An adriamycin (ADM)-resistant subline was established by continuous exposure of the SBC-3 cells, a cell line of human small cell lung cancer, to increasing concentrations of ADM, followed by the cloning procedure. The resistant sublines (SBC-3/ADM) thus established were 30-fold more resistant to ADM than the parent SBC-3 cells, in terms of the 70% lethal dose determined by soft agar clonogenic assay. The doubling times of the SBC-3 and SBC-3/ADM cells were 36 h and 22 h, respectively. When transplanted into athymic nude mice, the parent as well as resistant cells formed tumors, and serial passage was successful. Although the transplanted tumors from the two cell lines were very similar in histology, the resistance of the SBC-3/ADM cells to ADM developed in vitro was maintained in serially transplanted tumors. The uptake studies with [3H]daunomycin revealed decreased influx and enhanced active efflux of the drug in the resistant cells, whereas cytogenetic analysis showed that the cell lines had an identical karyotype. These results indicate that ADM resistance may be attributed to alternations in membrane transport, resulting in reduced intracellular accumulation of the drug.

The concentrations of taurine in the fetal and neonatal organs, and the maternal organs, plasma and urine of rats between the 15th day of gestation and the 21st day after birth were determined using an automatic amino acid analyzer. In the fetal liver and brain and in the placenta, the taurine concentration was the highest of all ninhydrin positive compounds. In the fetal liver and placenta, the concentrations of taurine increased significantly with the gestational days. Concentrations of taurine in the brain were much higher in the fetus and neonate than that in the adult. Moreover, the total amount of taurine per fetus increased markedly after the 15th day of gestation, and near term, reached almost the same amount as in the adult rat liver. In contrast to this, a significant decrease was observed in the taurine concentration in the maternal liver and muscle near term. The concentration of taurine in the urine of pregnant rats decreased near term, but in the plasma of pregnant rats the concentration of taurine did not change during pregnancy.

Type IV collagen-degrading enzyme activity was measured in liver homogenate obtained from 10 patients with hepatocellular carcinomas. Type IV collagen, the enzyme substrate, was extracted from human placenta with pepsin digestion, and labeled with [1-14C] acetic anhydride. The homogenate was preincubated with p-aminophenylmercuric acetate to activate the latent form of the enzyme, and then the enzyme activity was measured at pH 7.5 by adding a substrate mixture. Referring to previous reports, the enzyme measured seemed to be a neutral metalloprotease. The enzyme activity of the homogenate was markedly reduced by omitting the p-aminophenylmercuric acetate pretreatment, indicating that the enzyme was present mainly in the latent form. The activity seemed to be higher in the peripheral portion of hepatocellular carcinoma than in the center. Further the activity was found to be the highest in a hepatocellular carcinoma patient with many metastatic nodules in the lung. The results might suggest that type IV collagen-degrading enzyme participates in tumor invasion and intrahepatic or remote metastasis.

Using a cell line (SBC-3/ADM) of human small cell lung cancer, which is 30-fold more resistant to adriamycin than the parent cell line (SBC-3), the activity of a variety of anticancer agents was analyzed by soft agar clonogenic assay to search for a means of circumventing drug resistance. The SBC-3/ADM cells were markedly resistant to some anthracycline antibiotics in comparison with the SBC-3 cells: 28-fold for daunomycin, 26-fold for 4'-epiadriamycin, 18-fold for THP-adriamycin, and 8.4-fold for aclarubicin. However, the cells were as sensitive to mitoxantrone, one of the anthraquinone derivatives, as the parent cells. The cells were resistant to structurally or pharmacodynamically unrelated compounds such as vincristine, mitomycin C, and an active form of ifosfamide, whereas they were susceptible to cisplatin to some extent. The in vitro radiosensitivity of both cell lines was also evaluated, and they were found to be equally sensitive to X-ray. These results suggest that mitoxantrone and cisplatin may exert sufficient activity for small cell lung cancer which has acquired resistance to adriamycin, and that consolidative chest irradiation may be clinically useful after combination chemotherapy including adriamycin.

The influence of surgical stress on the natural killer (NK) activity of peripheral blood lymphocytes in patients with carcinoma of the lung or gastrointestinal system was studied. The peripheral blood lymphocytes of the patients showed a marked decrease in NK activity against K-562 cells as target cells 1-2 days after surgery. The activity remained lowered for 2 weeks after thoractomy and for 1 week after laparotomy. No appreciable suppression of NK activity was observed with normal human peripheral blood lymphocytes preincubated with postoperative patient sera. Peripheral blood mononuclear cells obtained postoperatively from patients lost NK activity after ultraviolet irradiation, without any detectable loss of viability. Such irradiated mononuclear cells showed inhibition of NK activity after a 24-hour preincubation with peripheral blood lymphocytes from normal subjects. Similar suppressive activity was demonstrable in a fraction of mononuclear cells with adhesiveness to plastic petri dishes, while non-adherent cells had no such activity. When added immediately to the cytotoxicity assay system without the 24-hour preincubation, patient mononuclear cells caused no inhibition of NK activity, whereas adherent cells from normal subjects enhanced NK activity. The findings seems to indicate that, following surgical stress, plastic dish-adherent peripheral blood mononuclear cells become deprived of NK helper activity and exert suppression, thus causing postoperative depression of NK activity.

The elimination of fibroblast-like cells from primary cultures of fetal human livers was studied. A fibroblast-like cell line (HuF), which was obtained by subculturing fetal human liver cells 4 or more times, was briefly treated with hydrocortisone (HC) or putrescine (PUT). The growth of HuF cells was inhibited by HC at a concentration of 10(-2) M and by PUT at a concentration higher than 10(-3) M. Long-term treatment of HuF cells with 10(-3) M HC inhibited the growth of the cells. Primary cultures of fetal human livers were made in medium containing HC or PUT, and morphological and functional examinations were made. The cultures were predominantly composed of epithelial-like cells, with few fibroblast-like cells, when the HC concentration was 10(-5)M to 10(-3) M. A high amount of albumin was secreted at these concentrations of HC. On the other hand, at 10(-3) M PUT, many epithelial-like cells were seen, but albumin was undetectable. The present results indicate that albumin-producing epithelial-like cells can be selectively maintained in medium containing HC, in primary cultures of fetal human livers.