Application of radioactive precursors for the evaluation of sensitivity of cancer cells to anticancer drugs

An in vitro drug sensitivity test was developed to estimate the lethal effects of drugs on cancer cells. Cancer cells were incubated in the presence of radioactive precursors and anticancer drugs. The drug effects were estimated from the changes in rates of incorporation of precursors into DNA, RNA, and protein. A microtiter plate and a multiple automatic cell harvester made feasible handling of a large number of samples. Incorporation of radioactive precursors was well correlated with drug-induced cell lethality. The results of this test were also correlated with in vivo regression of tumors of mice. This test appeared to be more reliable than other similar tests of cell lethality in vitro. For utilization in clinical studies, a test plate was simplified and 25 human cancers were tested. The in vitro results demonstrated a positive correlation with clinical results in 80% of the observations.

Isolation and characterization of vitamin A-sensitive Chinese hamster lung cell lines

Retinyl acetate (RA)-sensitive variants (RAs-2 and RAs-3) of V79 cell line were isolated after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. The variants were stable and showed a 3- to 4-fold increase in sensitivity to RA compared to parental V79 cells. The RAs-2 clone was also sensitive to retinol and retinol palmitate. The RA-sensitivity behaves as a recessive trait in all hybrids of RAs-2 and V79. A number of physiological parameters were indistinguishable in V79 and RAs-2 cells, including the extent of uptake of [3H]retinol, the release of K+ from the cells induced by RA, and the levels of retinol and retinoic acid binding proteins. However, one possible correlation with the RA-sensitive phenotype was observed: Gomori acid-phosphatase staining of RA-treated RAs-2 and V79 cells indicated that lysosomal membrane of RAs-2 cells was more labile than those of the parental V79 cells.

[Clinical evaluation of latamoxef, an oxacephem antibiotic with special reference to transport of latamoxef into the lung tissues and prevention of postoperative infections after thoracotomy]

There are few clinical reports about concentration of latamoxef (LMOX) in lung tissues. At present, clinically, we report a concentration of LMOX in serum and lung tissues on 21 patients of chest disease and a study of the administration schedule of LMOX for prophylaxis of postoperative infections on 31 operated patients with chest disease. Our results are the followings: The peak concentration of LMOX in serum is 77.4 micrograms/ml at 1 hour after starting drip infusion of LMOX 1 g. The concentration of LMOX in lung tissues is from 25% to 50% of serum level. LMOX is more useful to prophylaxis of postoperative infections after thoracotomy than cephalothin, especially in case of administration of LMOX just before operation. No side effects of LMOX are noted in our cases. LMOX has wide antibacterial activity against various clinical isolates and is useful to treatment of postoperative infections.

Verapamil enhances the efficiency of DNA-mediated gene transfer in mammalian cells

Treatment of Ltk- cells with the calcium antagonists, verapamil and diltiazem, but not nifedipine, causes a 3-fold enhancement of the frequency of transfer of the cloned gene for herpes simplex virus thymidine kinase (HSV-tk). The frequency of phenotypic expression of the HSV-tk DNA was 20 to 34 times higher than that of genotypic transformation. Phenotypic expression was also 2.3 to 2.6 times increased when 20 micrograms/ml of verapamil was present during calcium phosphate-mediated DNA transfection.

Chinese hamster cell mutant resistant to ML236B (Compactin) is defective in endocytosis of low-density lipo-protein

A fungal metabolite, ML236B (Compactin), isolated from Penicillium citrinum, is a specific inhibitor of 3-hydroxy-3-methylglutaryl (HMG)-coenzyme A reductase (EC 1.1.1.34). Three ML236B-resistant (ML236Br) mutants, MF-1, MF-2, and MF-3, were isolated from V79 after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. The fluctuation test showed 2.2 X 10(-6) mutants per cell per generation of a spontaneous mutation frequency of ML236Br clones. These ML236Br clones showed a four- to fivefold-higher resistance to the drug than did their parental V79. Radioactive acetate, but not mevalonate, incorporation into the sterol fraction increased about 10-fold in ML236Br clones in comparison with that in V79. The cellular level of HMG-coenzyme A reductase in three ML236Br mutants was found to be a few-fold higher than that of V79 when cultured in the presence of lipoproteins. The 125I-labeled low-density lipoprotein-binding assay showed binding activity in three ML236Br clones comparable to that of the parental V79 cells. By contrast, an internalization assay of 125I-labeled low-density lipoprotein into the cells showed significantly reduced activity in three ML236Br clones in comparison with V79.

[Clinical evaluation of cefotiam chloride in the surgical field, with special reference to its intrathoracic distribution and prevention of postoperative infections following thoracic surgery]

There are few report about the concentration of antibiotics in the tissue of intrathoracic organs. At present, it was analized the concentration in serum and tissue of intrathoracic organ and urinary excretion for CTM, and clinical effect against postoperative infection and side effect of CTM were discussed. 1) The peak concentration in serum was 48.7 micrograms/ml and half lives of CTM was about 30 minutes in 1 hour drip infusion of CTM 1g. 2) The concentration of CTM in lung tissue was about 30--50% of serum level. The concentration of CTM to pulmonary lesion was relatively high. 3) The concentration of CTM to the secretion of normal bronchiole was high as well. 4) The concentration of CTM to the bone marrow of rib was less than lung tissue. 5) Urinary excretion of CTM was 50--77% of total dose by 6 hours after injection. 6) CTM has wide spectrum and is useful to prophylaxis of postoperative infection. 7) It may be ineffective for Pseudomonas aeruginosa infection of lung.

Potentiation of antifungal effect of amphotericin B by squalene, an intermediate for sterol biosynthesis

The antifungal effect of a polyene antibiotic amphotericin B (AMB) was almost completely abrogated by exogenous addition of 0.1 microgram/ml ergosterol in the medium. The cytocidal effect of AMB on Saccharomyces cerevisiae was synergistically enhanced when cultured for more than 4 hours with squalene, an obligatory intermediate molecule for sterol formation. However, we could not find significant increase in cellular level of ergosterol content in the yeast cells fed with squalene.

Measurement of surface temperature in lung cancer

We measured the surface temperature of the tumors in 27 patients with primary lung cancer, using a flexible bronchofiberscope and a thermometer made from chromel-constantan. The thermometer was inserted into the aspiration channel of the bronchofiberscope, and temperature was studied under bronchofiberscopic located in the central portion of the lung were higher than those of the carina of the trachea (P less than 0.01), truncus superior (P less than 0.01), or truncus inferior (P less than 0.05), and almost equal to those of the peripheral lung. Thus, lung cancer showed a significantly higher surface temperature. When 67Ga scintigraphy was performed in 22 patients with lung cancer, the temperature of the high-uptake group was higher than that of the low-uptake group.

Differential effect of imidazole antibiotics on untransformed and virus-transformed rat cell lines

The imidazole antimycotics clotrimazole and miconazole were tested on untransformed rat cell line 3Y1-B clone 1-6 (3Y1) and six transformed cell lines, which were independently isolated from 3Y1 or 3Y1-B clone 1 after infection with adenovirus 12 (AD-12) or with SV40, to determine their sensitivities to these drugs. The relative plating efficiency of three cell lines (T3, W4, and W5) transformed with AD-12 was reduced to 10(-1( of the initial value by clotrimazole (2 to 4 microgram/ml), whereas that of the parental cell line 3Y1 was reduced to 10(-1) of the initial value by clotrimazole (20 to 25 microgram/ml). By contrast, the differential effect of miconazole on 3Y1 and AD-12-transformed cell lines was found to be a factor of 2. The sensitivity of the SV40-transformed 3Y1 and the AD-12-transformed cell lines. The cellular sensitivity of untransformed 3Y1 cells to clotrimazole was significantly enhanced when exposed to various doses of the unsaturated fatty acid, linoleic acid. The untransformed and transformed cell lines showed sensitivities similar to the cytocidal activity of sterol-binding antimycotics, amphotericin B and filipin.

Enhancement of the antitumor effect of 6-mercaptopurine by vitamin A

The inhibition of the growth of HeLa cells in culture by 6-mercaptopurine was greatly enhanced in combination with retinol, retinal or retinol acetate, but not in combination with retinoic acid or retinol palmitate. The antitumor effect of retinol palmitate combined with 6-mercaptopurine was examined in BDF1 mice with L1210 leukemia. The blood level of retinol, a strong potentiator of 6-mercaptopurine among vitamin A compounds, was increased in BDF1 mice after retinol palmitate injection. Retinol palmitate was found to enhance the antitumor effect of 6-mercaptopurine against murine L1210 leukemia to a significant extent (69% increase in life span).

Isolation and characterization of Chinese hamster ovary cell mutants with altered sensitivity to high doses of tunicamycin

A mutant, CTM422, resistant to low dose of tunicamycin (TM) was isolated from Chinese hamster ovary (CHO) cells, and it showed 7- to 10-fold higher resistance to TM than CHO. We further mutagenized CTM422, to isolate TM-high-resistant mutants which were resistant to about 100-fold higher dose of TM than CHO. The TM-high-resistant mutants (N101 and N102) acquired about 4-fold higher cross-resistance to 2-deoxy-d-glucose than CHO or CTM422, while both CHO and CTM422 showed similar sensitivity to 2-deoxy-d-glucose. TM-low-resistance appeared to be codominant, and TM-high-resistance was partially codominant against TM sensitivity, respectively. The transfer activity of N-acetylglucosamine from UDP-N-acetylglucosamine into the lipid fraction with CHO and CTM422 cell extracts was inhibited by TM to a similar extent, while the extract of N102 cells showed about 10-fold higher resistance to TM than CHO or CTM422.

Operative procedure and indications for surgical management of pulmonary metastasis of choriocarcinoma

From 1961 to 1977, thoracotomy was performed on 19 patients with pulmonary metastasis of choriocarcinoma in Nagoya University with regard to the role of thoracotomy in management of pulmonary metastasis of choriocarcinoma. Our surgical indications for the disease are: 1) the patients must be a good risk for surgical intervention. 2) The primary malignancy be controlled. 3) Evidence of pulmonary metastasis be limited to the lung. 4) The urinary human chorionic gonadotropin (hCG) titers should be controlled at low levels below 1000 mIU/ml by preoperative chemotherapy. At levels below 200 mIU/ml, the indication for surgery will be assessed by the cellular response to chemotherapeutic agents. As an operative procedure, in view of a low incidence of lymph nodes metastases, extended pulmonary surgery appears to be unnecessary providing that the gross pulmonary lesion is removed by partial resection of the lung or lobectomy. Postoperative adjuvant chemotherapy is required to induce a complete remission of the choriocarcinoma.

Isolation and preliminary characterization of bleomycin-resistant mutants from Chinese hamster ovary cells

Stable mutants resistant to an anticancer antibiotic, bleomycin-A2, were selected in Chinese hamster ovary (CHO) cell either spontaneously or after ethylmethane sulfonate mutagenesis. Fluctuation analysis showed that bleomycin resistance occurs in CHO at a rate of 6.50--6.58 x 10(-7) mutations per cell per generation. Bleomycin-A2-resistant cell lines exhibited increased resistance to bleomycin analogs--bleomycin-A5, -B2, -B4, and pepleomycin. Colchicine, mitomycin C, and ultraviolet light irradiation inhibited colony formation equally in CHO cells and in bleomycin-resistant mutants. Cell-cell hybridization tests showed that bleomycin-resistance behaves as a dominant trait. Bleomycin-inactivating activity in the mutant cell extracts was three to fourfold higher than that in extracts of the parental CHO cell.

Esophageal cyst, a case report and a review of the literature

The esophageal cyst is a rare disease only 20 cases of which have been reported in the literature in Japan. We recently treated such a patient and at thoracotomy, we found the cyst to be located the submucosal layer of the esophagus. The cyst could be easily extirpated and the patient made an uneventful recovery. Gross findings revealed thick, yellow and mucus-like contents inside the cyst. Microscopically, the cyst was lined with ciliated columnar epithelium and there was no evidence of cartilage. The 21st such occurrence in Japan is reported herein and a discussion is made of related literature.

Classification of polyene antibiotics according to their synergistic effect in combination with bleomycin A2 or fusidic acid

Five polyene antibiotics were compared for their effects on colony formation of either Chinese hamster V79 or Saccharomyces cerevisiae cells. A 10 to 40 times higher concentration of amphotericin B (heptaene) or nystatin (degenerated heptaene) was necessary to inhibit colony formation of hamster cells than that needed to inhibit colony formation of yeast cells. In contrast, colony formation of both hamster and yeast cells was inhibited to the same extent by similar concentrations of filipin (pentaene), pentamycin (pentaene), or pimaricin (tetraene). The five polyene antibiotics were also compared for their effects on colony formation of either V79 or S. cerevisiae cells when combined with a nonpolyene antibiotic, fusidic acid or bleomycin A2. Amphotericin B or nystatin could augment the cytocidal effect of fusidic acid but not that of bleomycin A2, whereas pentamycin or pimaricin could augment the cytocidal effect of both fusidic acid and bleomycin A2 against hamster and yeast cells. Filipin was found to enhance the action of fusidic acid and bleomycin upon growth of mammalian cells, whereas the pentaene polyene significantly potentiated the action of fusidic acid, but not that of bleomycin A2, against S. cerevisiae. It was therefore suggested that these polyene antibiotics be classified into two groups: group 1 (pimaricin, pentamycin, and filipin) and group 2 (amphotericin B and nystatin).

Synergistic effect of vitamin A and fusidic acid on Hela cells in vitro

Examinations were made to see if various vitamin A compounds, including retinol, retinal, retinol palmitate, retinol acetate, and retinoic acid, enhance the action of fusidic acid, an antibiotic and inhibitor of protein synthesis, on human carcinoma HeLa cells in vitro. Among these vitamins, retinal and retinol were found to potentiate strongly the effect of fusidic acid on HeLa cells. In this system, however, retinol palmitate, retinoic acid, and retinol acetate in 10 approximately 20 microgram/ml concentration were not found to enhance the effect of fusidic acid significantly.