Acta Medica Okayama volume37 issue4

The effects of surgical intervention by removal of the primary focus, and the effectiveness of an immunomodulator, Corynebacterium parvum (Cp), on the proliferation of metastatic tumor tissue were investigated by following the postoperative changes in the 3H-thymidine labelling rate of metastatic tissue in an experimental model of metastasis in mice. In addition, the delayed type hypersensitivity reaction (DTH) was studied to investigate the immune capacity of the host. The labelling rate of mice that had the primary focus removed remained high with little variation, while that of the mice not operated on decreased gradually. On the other hand, in mice undergoing a sham operation, the rate was the same as that of the mice with the primary focus removed for a short while, but then gradually decreased. When Cp was administered, especially before removal of the primary focus, the rate was lower than that of the tumor bearing control group and decreased steadily. The number of pulmonary metastatic nodules was increased by removal of the primary focus, but this increase was inhibited by the administration of Cp which prolonged life. The depression in the DTH was less in the group given Cp preoperativeLy than in either the group of mice having the primary focus removed or those not having it removed.

Antibody-dependent cellular cytotoxicity (ADCC) increased with the development of tumors in C3H/He mice bearing spontaneous breast cancer or the syngeneic hepatoma MH-134 and in C57BL/6 mice bearing the syngeneic Lewis lung carcinoma 3LL. This cytotoxicity decreased after treatment with guinea pig, monoclonal IgM anti-Thy 1.2 serum and complement to the non-cancer level thus indicating that the increased ADCC in mice with cancer seems mainly attributable to cells with the Thy 1 antigen. On the other hand, NK activity decreased greatly when mice had tumors. Treatment with monoclonal IgM anti-Thy 1.2 serum and complement showed no significant influence on the natural killer (NK) activity of spleen cells of mice bearing MH-134 cancer, but in the 3LL-bearing mice the activity decreased significantly.

Serum neutral amino acid levels in cirrhotic patients with abnormal oral glucose tolerance test patterns were not different from those of subjects without impaired carbohydrate metabolism. However, the characteristic features of serum aminograms in the patients, that is, increased levels of tyrosine, decreased levels of valine and leucine and the diminished ratio of branched chain amino acids to phenylalanine and tyrosine levels, were less pronounced in those treated with insulin. This finding is clinically important for evaluating the serum aminogram of cirrhotic patients under insulin therapy.

We investigated the restriction of the host range to infectivity of MSV by helper leukemia virus in vivo. When newborn SD-rats were inoculated intracerebrally, subcutaneously, intraperitoneally or intramuscularly with xenotropic pseudotype Kirsten MSV, Ki-MSV(BV2), either brain tumors or myogenic sarcomas were induced, depending upon the route of inoculation. However, no tumors developed in SW-Icr mice inoculated with Ki-MSV(BV2) either intracerebrally or intramuscularly at birth. Ecotropic Ki-MSV(Ki-MuLV) induced myogenic sarcomas in mice when inoculated intramuscularly and also induced brain tumors and myogenic sarcomas in rats when inoculated intracerebrally and intramuscularly, respectively. Thus, the host range of pseudotype MSV appeared to depend on a helper leukemia virus.

A new nutritional product (SF-1008C) containing a high proportion of branched chain amino acids (BCAA) and low proportion of aromatic amino acids (AAA) and methionine was tested to see its effect on the impaired protein metabolism and abnormal nutritional state frequently observed in patients with advanced liver cirrhosis. A sharp increase in plasma BCAA levels and fall of AAA and methionine levels were found following the administration of an SF-1008C-supplemented diet to healthy controls and cirrhotic patients, which the BCAA levels increased only slightly following an isocaloric control diet. Blood ammonia levels increased within the normal range transiently following the diets. The SF-1008C-supplemented diet was given for 2 weeks to cirrhotic patients with histories of hepatic encephalopathy, who were taking a low-protein diet because of hyperammonemia. Serum prealbumin levels, nitrogen balance, molar ratio of plasma BCAA/phenylalanine and tyrosine, the number connection test and electroencephalograms improved during the period of the experimental diet. The results, therefore, indicate that a BCAA-supplemented diet is well tolerated by patients with advanced cirrhosis and useful for treatment of impaired protein metabolism. Furthermore, this product is beneficial in preventing hepatic encephalopathy in cirrhotics.

The morphological and biological changes in long term culture cells of normal-appearing trigeminal nerves from 2, 8, and 30-day-old S-D rats administered transplacentaLly with 75 mg ENU/kg were examined. After a marked degeneration of cells, crisscross multiple proliferative foci of transformed spindle cells appeared at the 3rd passage culture from 2 and 8-day-old rats, but not form 30-day-old rats. The transformed cells with S-100 protein and basal lamina had Schwann cell characteristics. Transformed spindle cells continued to form a crisscross pattern more than 700 days and some transformed spindle cells became round in shape 3-6 months after the primary culture. These transformed cells were transplantable to newborn S-D rats and the transplanted tumors were histologically similar to those of malignant Schwannoma of trigeminal nerves induced by ENU. Round-shaped transformed cells were more malignant than spindle-shaped cells and produced rapidly growing transplanted tumors. Spontaneous transformation with multinucleated giant cells occurred in one of the control cultures. These results indicate that the sequential changes of ENU-treated trigeminal nerves in vitro were corresponded to developmental changes of malignant Schwannoma in vivo induced by ENU. This system will be useful for analysis of ENU-carcinogenesis.

A microinjection of ferric chloride solution into the left frontal cortex of rats induced epileptic discharges which were recorded by electrocorticography. In animals having such electrographic seizure activity 30 to 60 days after the injection, the accumulation of cyclic AMP elicited by norepinephrine was examined in slices from four cortical regions. The accumulation was significantly greater in the left anterior area, into which region the ferric chloride solution was injected, than in the right anterior area. There was also a tendency for greater norepinephrine-elicited accumulation of cyclic AMP to occur in the left posterior area than in the right posterior area.

An epileptic focus not resulting in generalized convulsions was induced by a microinjection of ferric chloride solution into the left anterior cortex of rats. The formation of the epileptic focus was confirmed by the appearance of bilateral spike and slow wave complexes as well as focal isolated spikes in electrocorticograms (ECoGs). The effect of glutamate on cyclic AMP accumulation was examined in incubated slices prepared from four quadrants of the epileptic cortex. In animals showing isolated spikes 8 to 10 days after the microinjection, the effect of glutamate on cyclic AMP accumulation was stimulatory. It was greatest in the left anterior quadrant which included the injection site, but only slight in the left and right posterior quadrants. In animals showing spike and slow wave complexes 30 to 60 days after the microinjection, the stimulatory effect of glutamate was also most pronounced in the left anterior quadrant. In the right anterior and the left posterior quadrants glutamate had almost no effect, while in the right posterior quadrant, glutamate was inhibitory.

The susceptibility of Rous sarcoma virus (RSV) genomes integrated in mouse ascites sarcoma cells (SR-C3H/He cells) to DNase I and DNase II was investigated. Approximately half of the viral sequences were sensitive to DNase I and DNase II when 17% and 7.4% of the chromatin DNA was rendered acid soluble, respectively. The results suggest that newly acquired exogenous proviral sequences are integrated into both transcriptionally active and inactive regions of chromatin in cells lacking related endogenous viral sequences.

The localization of both the large T and small t tumor (T) antigens in cultured cells (Vn 12 cells) of hamster brain tumors induced with BK virus (BKV), a new human papovavirus, was studied by an enzyme labelled antibody method at both the light and electron microscopic levels. Under the light microscope, BKV T antigen was observed in the nucleus, except for the nucleoli, of cells in interphase, and under the electron microscope it was observed in the nucleus except for the nucleoli and nuclear membrane. BKV T antigen appears to be closely associated with nuclear chromatin as previously reported for simian virus 40 tumor antigen (SV40 T antigen). The intracellular localization of BKV T antigen was the same as that of SV40 T antigen. In metaphase, BKV T antigen seems to be distributed diffusely throughout the cytoplasm except for the chromosomes. In telophase, BKV T antigen transfers from the cytoplasm to the nucleus. The migration of BKV T antigen during the cell cycle is thought to be related to the function of T antigen.

Cancer cells obtained from human hepatocellular carcinoma nodules were subjected to primary culture, and a hepatoma cell line was established. The cell clumps obtained by needle puncture were plated directly in plastic tissue culture flasks without any cell dissociation procedures. Cell clusters became attached to flasks in 24 h with an efficiency of about 90%. No fibroblast outgrowth was observed. Primary cultured cells were composed of polygonally shaped epithelial cells with dense cytoplasm and one or more large nuclei. They excreted plasma protein biosynthetic markers of hepatocytes into the culture medium. Plasma protein synthesis of primary cultured hepatoma cells decreased as the age of the primary cultures increased. Cells seeded in September 1980 started to grow continuously after 5 months of cultivation. A new hepatocellular carcinoma cell line (designated as KG55T) was established from these growing cells. KG55T cells have been subcultured for more than 20 passages and form a monolayer of polygonal epithelial cells which pile up after they reach confluence. The cells had a doubling time of 50-60 h and a plating efficiency of 60-65%. Albumin, alpha 1-antitrypsin and alpha 2-macroglobulin syntheses and tyrosine aminotransferase activity were detected. At the 10th passage, KG55T cells were pseudotriploid (mode, 69), and 8q+ and 15q+ translocations were distinctive of this cell line. The morphological characteristics and the capacity for plasma protein synthesis of the primary cultured hepatoma cells and cells of the established hepatoma cell line were compared.