Protein synthesis and tumorigenicity of the cytoplasmic hybrid between rat yolk sac tumor and mouse fibroblastic cell line.

Cytoplasmic hybrid (cybrid) cell lines were formed by fusing whole cells of rat yolk sac tumor cell line (EST-II) with cytoplasts of mouse fibroblastic cell line (B-82cap), a variant of mouse L cell line that is deficient in thymidine kinase (TK-) and resistant to chloramphenicol (capr). The cybrid cell line with the nucleus of EST-II and cytoplasma of B-82cap was successfully obtained using double selection with HAT and chloramphenicol-containing medium. The cybrid's ability to synthesize proteins such as albumin, alpha-fetoprotein, gamma-EST, and gamma-GTP was found to be approximately one-fourth that of the nuclear donor, EST-II, at a early time of growth in culture, but this was followed by a gradual increase during the period of observation. The nude mice undergoing subcutaneous transplantation of 1 X 10(6) cells of EST-II and cybrid were killed by the tumor growth, with the survival time being 56 +/- 11 and 105 +/- 25 days, respectively. The histologic findings of cybrid tumor closely resembled those of the nuclear donor, EST-II. These facts suggest that factors from both the nucleus and cytoplasma will be able to affect the gene expression of the cybrid cell line.

Induction of malignant fibrous histiocytoma in female Fisher rats by implantation of cyanoacrylate, zirconia, polyvinyl chloride or silicone.

Five kinds of foreign bodies (silicone, cellulose, polyvinyl chloride, zirconia and alkyl-alpha cyanoacrylate) were implanted into subcutaneous tissue of female Fisher rats. Subcutaneous tumors were induced in 27.3, 54.5, 100, 63.6% of rats by silicone rubber, polyvinyl chloride, zirconia and alkyl-alpha-cyanoacrylate, respectively, but not by cellulose. Almost all tumors were composed of a mixture of cells that resembled fibroblasts characterized by the presence of numerous rough-surfaced endoplasmic reticulum and Golgi apparatus, histiocytes characterized by developed endoplasmic reticulum and abundant lysosome, myofibroblasts characterized by the presence of both myofibrils and fibroblast-like structures, and immature mesenchymal cells. In some tumors, the cells exhibited a storiform pattern. Some tumor cells were positively stained by ED2 or anti-muscle actin antibody. The features of induced tumors in rats were consistent with those of human malignant fibrous histiocytoma. A rat malignant fibrous histiocytoma transplanted into the subcutaneous tissue of the syngeneic female Fisher rats grew and metastasized to the lungs.

[Levofloxacin concentrations in serum, sputum and lung tissue: evaluation of its efficacy according to breakpoint].

The levels of levofloxacin (LVFX) in the serum, sputum and lung tissue were measured by a high-performance liquid chromatography method, and the penetration ratio of LVFX into respiratory tissue was investigated. The subjects of this study were 23 patients under pulmonectomy or brochoscopy. LVFX at the dose of 200 mg was given orally and specimens were collected as follows; serum at 2, 3 and 5 hours after, sputum at 2 hours after, and lung tissue at 3 and 5 hours after the administration, respectively. The mean level of LVFX in lung tissue at 3 hours was 3.91 +/- 2.33 micrograms/g, and those in sputum and in serum at 2 hours were 0.71 +/- 0.63 and 2.08 +/- 1.01 micrograms/ml, respectively. A very strong correlation was demonstrated between the level of LVFX in lung tissue and that in serum (p < 0.0001), but correlation between those in sputum and in serum was not significant. The penetration ratio of LVFX into lung tissue was 217.2% and that into sputum was 4.05%. Based on the results of this study, the breakpoints (BPs) of LVFX for pneumonia and chronic respiratory tract infections were calculated to be 4 micrograms/ml and 1 microgram/ml, respectively. It was concluded that penetration of LVFX into lung tissue was satisfactory, and the tissue level of LVFX exceeded greatly the MIC90s against the typical pathogenic bacteria of respiratory tract infections. Taking the excellent BP for pneumonia, 4 micrograms/ml, into consideration, it was thought that LVFX is an effective antibacterial agent against pneumonia and other respiratory tract infections.

[Effects of gold on age-hardening in Ag-25 wt. % Pd-7 wt. % Cu alloys (author's transl)].

Effects of third elements (0, 1, 2, 4, 6, 8 and 12 wt. % Au) on the age-hardening in Ag-25 wt. % Pd-7 wt. % Cu alloys were studied by means of electrical resitivity, micro-hardness measurement, optical microscopy observation and X-ray diffraction. The results are summarized as follows. (1) The temperature range of an initial increase in resistivity was lowered with increasing concentration of gold. (2) The age-hardening process was retarded by the addition of gold. (3) Changes in X-ray diffraction patterns which was aged at lower temperature range exhibited that continuous precipitation process. On the other hand, changes in diffraction patterns aged at higher temperature range showed discontinuous precipitation process. (4) The lattice parameters of alpha phase and alpha2 phase (Ag-rich) were found to decrease with increase in gold content, while the lattice parameter of PdCu type superlattice was found to increase with increase in gold. (5) The nature of the interface between precipitates and the matrix was discussed on the basis of the changes in lattice parameter obtained.

Inverse scattering problem for mixed-phase and ice clouds. I. Numerical simulation of particle sizing from phase-function measurements.

We propose a new method of particle size retrieval for mixed-phase and ice crystal clouds. The method enables us to identify each component of a bicomponent cloud composed of water droplets and ice crystals and to retrieve a size distribution separately for each cloud component. We explore the method's capability by using sythetic multiangular data of scattered-light intensity. We model cloud microphysical characteristics by assuming two noninteracting cloud components, such as liquid or supercooled droplets and cubic or hexagonal ice crystals, with regular simple geometrical shapes as first approximation. The sensitivity of the method is tested for different relative concentrations of the cloud components that are varied over a wide range. First, we investigate the applicability limit of the single-component cloud approximation in retrieving particle size distributions of a bicomponent cloud. Second, we test the method to retrieve size distributions simultaneously for both components in mixed-phase clouds, and we discuss the conditions of its applicability.

Establishment of a human colon adenocarcinoma cell line producing carcinoembryonic antigen.

A human adenocarcinoma cell line was successfully established from the lymph-node metastasis of transverse colon cancer. Primary culture was done with the tumor developed in a nude mouse which had been inoculated with the metastatic lymph node. Morphological characteristics, growth kinetics, chromosomes, tumorigenicity and high production of carcinoembryonic antigen by the established cells are described. This cell line should be a useful tool for studies on the mechanism of re-expression of the fetal gene which is responsible for carcinoembryonic antigen expression in colon cancer cells.

Production of alpha-fetoprotein by cultured rat ascites hepatoma cells determined in vivo as alpha-fetoprotein-negative.

Three ascites hepatoma cells of the rat, AH-41B, AH-34, and AH-64B, which had been determined in vivo as alpha-fetoprotein-negative, were cultivated in vitro in a medium containing adenosine 3',5'-cyclic monophosphate (cyclic AMP), cyclic dibutyryl-AMP, or theophylline. The concentration of alpha-fetoprotein in culture media was measured by the 125 I-radioimmunoassay. Results demonstrated that the AH-41B cells produced alpha-fetoprotein in vitor, the concentration of which being elevated in the media with three substances, while the remaining AH-34 and AH-64B cells did not. A comment was made on the producibility of alpha-fetoprotein in the so-called alpha-fetoprotein-negative hepatoma cells.

Alpha-fetoprotein and albumin produced by subclonal cell population of the ascites hepatoma AH-66 in vitro.

Subclonal cell populations were prepared from a clonal line of the rat ascites hepatoma AH-66 in vitro, using the agar plate culture method. alpha-Fetoprotein and albumin concentrations in culture media of these subclones were determined by 125I-radioimmunoassay and single radial immunodiffusion method, respectively. Results demonstrated that the AH-66 clone was a complex of cells with varying producibility of alpha-fetoprotein and albumin. All the subclones showed varied and distinct production of alpha-fetoprotein, but not all the subclones produced detectable levels of albumin.

Immunoradioautographic study of alpha-fetoprotein in hepatoma cells.

Trypsin treatment, which is frequently used in the field of immunocytochemistry to faciliate conjugated antibody penetration through the cell membrane, was applied for the immunoradiographic demonstration of alpha-fetoprotein in ascites hepatoma cells using 125I-labeled anti rat alpha-fetoprotein antibody. No significant number of silver grains were detectable in the group without trypsin treatment, while numerous silver grains were recognizable in the ascites hepatoma cells after trypsin treatment. This indicates that trypsin treatment is effective for the immunoradiographic demonstration of alpha-fetoprotein and contributes to the quantitative immunoradioautographic investigation.

Suppression of tumorigenicity in interspecific reconstituted cells and cybrids.

The effect of cytoplasms on the expression of tumorigenicity was examined in interspecific reconstituted cells and cytoplasmic hybrids (cybrids) formed by fusions between karyoplasts (or intact cells) from highly tumorigenic mouse melanoma B16 cells and cytoplasts from non-tumorigenic, hypoxanthine-guanine phosphoribosyl-transferase (HGPRT)-deficient and chloramphenicol (CAP)-resistant rat myoblastic cells, L6TG X CAPr. The reconstituted clones and cybrid clones isolated in the double selection medium, HAT and CAP, acquired CAP-resistance, and each showed unique morphology and cellular arrangement. Tumorigenicity was suppressed in all the reconstituted clones and cybrid clones examined at an early stage after their isolation, but re-appeared in some clones after prolonged cultivation of the cells.

Tumors of Sprague-Dawley rats induced by long-term feeding of phenacetin.

Carcinogenicity of phenacetin was tested using Sprague-Dawley rats. Two groups of animals containing 50 males and 50 females per group were fed respectively with 2.5% and 1.25% phenacetin diet for 18 months and fed thereafter with basal diet for 6 months. Control animals containing 65 males and 65 females were fed with basal diet for 24 months. Animals surviving more than 24 months were regarded as effective animals and killed. Rats that died of tumor development within 24 months were also regarded effective animals. Every organ from the killed and dead animals was fixed in 10% formaldehyde solution and examined histopathologically. Effective number of rats was 27 males and 27 females in 2.5% phenacetin feeding group, and 22 males and 25 females in 1.25% phenacetin feeding group. In control group, 19 males and 25 females were effective. Neoplasms including spontaneous tumors were detected in 26 out of 27 males (96.3%) and 21 out of 27 females (77.8%) of 2.5% phenacetin feeding group, and in 20 out of 22 males (90.9%) and 19 out of 25 females (76.0%) of 1.25% phenacetin feeding group. In control group, 1 out of 19 males (5.3%) and 6 out of 25 females (24.0%) showed spontaneous tumor development. Histopathologically, carcinomas of the nasal cavity, such as adenocarcinoma, squamous cell carcinoma, and transitional cell carcinoma, and the urinary passage, as renal cell carcinoma of the kidney pelvis, and transitional cell carcinoma of the urinary bladder, were most conspicuous, suggesting the target organs of phenacetin carcinogenesis. Males showed higher tumor incidence compared to females. The higher the concentration of phenacetin given, higher incidence of tumors was observed.