The present study was undertaken to further clarify the unique features of the structure and function of the mitochondrial ribosomal RNAs (rRNAs) of animal cells.
1) The entire mitochondrial genome of the bullfrog, Rana catesbeiana, was cloned into a plasmid vector pBR322 at the unique Bam HI site, and the nucleotide sequences of the small (12S) and large (16S) rRNA genes and their flanking ND1 and two tRNA genes were determined. The organization and the directions of the transcription of these genes were exactly the same as those of the mitochondrial genomes of the five animal species so far known.
2) The Rana catesbeiana 12S and 16S rRNA genes consisted of 937 and 1, 585 bases, respectively. The nucleotide sequence homologies of each gene to their counterparts in other animals were in the range of 66 to 75%. These values are much lower than the 95% observed among nuclear-encoded cytoplasmic rRNAs of the five animals, indicating that mutations occur faster in the mitochondrial than in the cytoplasmic rRNAs. As to the base composition, the GC contents of the 12S and 16S mitochondrial rRNAs of Rana catesbeiana were 43 and 40%, respectively, which are also characteristically low as compared with the values of 55% in the E. coli and 60% in the cytoplasmic rRNAs.
3) The putative secondary structures of the mitochondrial rRNAs of Rana catesbeiana were drawn by the comparative analytical method, based on the proposed models for E. coli and some cytoplasmic rRNAs. In spite of the considerable differences in size and base compositions found in the rRNAs from different species and different organelles, the secondary structures of the mitochondrial rRNAs were highly conserved, implying that these structures are essential for the functioning of rRNAs.
4) The ND1 gene of Rana catesbeiana was encoded by 961 bases and, as deduced from the nucleotide sequence, the ND1 product consisted of 320 amino acids with a molecular weight of 35, 714. The nucleotide and amino acid sequence homologies of the ND1 between Rana and human and between Rana and Xenopus laevis were 67 and 66%, and 70 and 74%, respectively, indicating that the ND1 sequence is conserved to similar extents as those of other mitochondrial-encoded proteins.
5) The nucleotide sequences of tRNA-Val and tRNA-Leu (UUR), adjacent to the rRNAs and NDI genes, and the clover leaf structures of these tRNAs were also determined, which showed characteristic features seen in the mitochondrial tRNA genes of the higher animals.

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Mouse liver arginase was purified according to the procedure set out by Grol et al., 1983. Partially purified arginase had a molecular weight of 110, 000 when measured by gel chromatography and it exhibited two discrete protein bands on SDS-PAGE at molecular weights of 43, 000 and 40, 000, respectively. Partially purified arginase inhibited the proliferation of Sp2 cells in a dose-dependent manner. Additional arginine rescued Sp2 cells from this inhibition. When intracellular arginase activity in Kupffer cell rich fraction isolated from 70% hepatectomized mice was measured, the arginase activity reached a peak, about four times above the control level, at 2 days after partial hepatectomy and then returned to the control level at 11 days after the operation. These data suggest that strong arginase activity in Kupffer cells is induced by their activation during liver regeneration. The possibility of regulating liver regeneration and the immune system by Kupffer arginase was discussed.

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Eight male adults (20-23 years of age) were induced to perform a mild (1.5 Kp) upright ergometer exercise for 5 minutes. The aforesaid subjects' BP and HR, before (0 min as the initial point), during (2, 4, 5 min) and after (7, 10, 15, 20, 25, 30, 60, 90, 120, 150, 180 min) the exercise were recorded sequentially. At the same time points, (except for 15 min), blood specimens were collected from an indwelling anticubital catheter and the plasma noradrenaline level (PNA) was measured by high performance liquid chromatography with electrochemical detection.
The sequential changes of BP, HR and PNA were simulated in our mathematical model of multiexponential functions as follows: ΣAi·exp (-Bi·t) (t; time).
Furthermore the relations among those parameters derived from the above simulation procedure such as A_ij and B_ij were analysed. In these equations i and j designate respectively individual function and physiological indicators, which include BP, HR and PNA.
The results from the statistical analysis of the relationships existing among the parameters suggest that the BP change is one of the best indicators of stress in the sympathetic nervous system after exposure to physical stress.

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2, 533 workers using hand held tools (vibration tools, tools with triggers) in A factory were examined by the method referred to the notification of the Labors Standard Bureau, i.e. hand grip strength, finger skin temperature, vibration sense threshold and subjective symptoms. The analyse were made on 1, 976 male workers who satisfied all requirements for the examination.
The purpose of this study was mainly aimed at prevention of the health hazards due to tool operation. Then, we defined the standard limit values on the respective physiological tests, and divided the workers into two groups judging from the defined limits: either above or below the levels, which are considered to demarcate normal and abnormal values. We counted the number of workers having a trigger finger like phenomenon in the respective groups, and investigated which physiological tests were useful for predicting the minimum functional lesions in hands. Through comparing these distributions of abnormal person on the respective tool groups and on the groups divided by the duration of their tool operation, we could make some conclusions about the relationship between the health hazards and the factors relating to tool operation. And from the present investigation, we could derive a certain preventive method with which we would have the latent changes not turned to detectable lesions, such as trigger finger and Raynaud phenomenon. Key words: vibration tool, trigger finger, Raynaud phenomenon, automobile factory, industrial health

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Bullfrog tadpoles, Rana catesbeiana, ranging from St. 17(Taylor and Kollros 1946)to St. 25, and froglets 3 months after completion of metamorphosis were used for the study of the myenteric plexus neurons in the small intestine. The enf ace preparations of the intestinal wall were made along the whole length of the small intestine and impregnated with silver nitrate using the Gros-Bielschowsky method. The neurons were classified into two basic types at the pre-metamorphic stage: the first one was a slender type of cell (Photo 1, 2), and the second was a polygonal cell with radiating dendrites (Photo 3).
The first type was distributed throughout the wall of the oral area to the opening of the pancreaticoduodenal duct ("oral area") and the vicinity of the mesenteric attachment in the anal area to the opening of the pancreatico-duodenal duct ("mesenteric attachment area"). The second type was distributed throughout the wall of the anal area to the opening of the pancreatico-duodenal duct ("anal area").
The first type of cell was transformed into a small unipolar cell at the climax stages of metamorphosis (St. 21-22) and began to appear in the oral area and the mesenteric attachment area at St. 23 and increased in number thereafter. The second type of cell disappeared at St. 21 from the anal area, where the smaller sized polygonal cells began to appear at St. 23 and increase in number thereafter. In this case only a few polygonal cells with radiating dendrites appeared in the anal area. This was the difference between the pre-and post-metamorphic stages in the distribution pattern of neurons.

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1) The monthly Reimbursement Claims under the Japanese National Health Insurance System for stroke and cancer patients in a farming community were scrutinized and analyzed with Hayashi's Quantification Method. It was revealed that the data in the Reimbursement Claim for the first month of treatment predicts, with practical validity. (1) the medical costs for the initial 6 months, and for the first year, and (2) the outcome (survival or death) after the periods mentioned above.
2) Stroke “The average medical cost per day of the first month” was the most significant contributory factor for the prediction of the medical costs for the initial 6 months of treatment. The three main contributory factors for the prediction of the medical costs for the first year of the treatment were “admission/non-admission in the first month”, “the average medical cost per day for the first month” and “the patients' place of residence”.
“The patients' age at the time of the first visit to the hospital” was one of the most significant contributory factors for the prediction of the outcome at the end of the initial 6 months of treatment. “The patients' age at the time of the first visit” and “the patients' place of residence” were the most significant contributory factors for the prediction of the outcome after one year of treatment.
3) Cancer Both “the average medical cost per day of the first month” and “the patients' age at the time of the first visit” contributed to the prediction of medical costs for the initial 6 months, and for the first year. This prediction, however, was less evident than the medical cost prediction for stroke patients.
“The patients' age at the time of the first visit” and “the patients' place of residence” were associated with the outcome at the end of the initial 6 months, and the first year of treatment.
4) The monthly Reimbursement Claims, which are presently being utilized for claiming and record-keeping purposes only, could offer us extremely useful information for the prediction of medical costs and of the outcome. It is therefore suggested that these Claims, and the data therein, be utilized for administrative planning and budgeting purposes as well.

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A total of 26 specimens of human gastric cancer were used for subcutaneous transplantation into nude mice. Seven transplantable tumor lines were established, and the transplantability rate was 27%. The gastric cancers and the xenografts of the tumor lines were studied histochemically. The cancer cells were examined for the presence of epidermal growth factor (EGF), and stromal changes were examined for the localization of factor VIII, laminin and alkaline phosphatase (ALP). EGF was present in 14 (54%) of the gastric cancers, and in all of the xenografts. Five-tumor lines were derived from EGF-positive cancers (5/14, 36%), and two lines from EGF-negative ones (2/12, 17%). The transplantability rate of EGF-positive cancers was higher than that of EGF-negative cancers. The xenografts consisted of human cancer cells and stroma which contained blood vessels and fibroblasts. These blood vessels were negative for human factor VIII, but positive for laminin and ALP, while those in the human cancers were positive for all of them. This suggests that the blood vessels in the xenografts were not human, but newly formed ones from the nude mice. ALP activity was observed in some cancer cells, blood vessels, and fibroblasts. The fibroblasts showed ALP-activity at the cytoplasmic membrane and at a well developed rough endoplasmic reticulum electron-microscopically. ALP-positive fibroblasts were not noted in normal human gastric tissue and in the subcutaneous tissue of nude mice. These results suggest that the proliferation of cancer cells requires EGF produced by cancer cells and stromal change, namely, angiogenesis and the appearance of ALP-positive fibroblast.

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Stromal factors in cancer tissue provide an adequate microenvironment for cancer cell(s) to appear, grow, and invade.
In the present work, neovascularization and the interaction between cancer cell(s) and fibroblasts in relation to tumor growth have been studied histochemically; this was done by inoculating nude mice with gastric cancer cell lines (MKN 28, MKN 45, KATO III). Furthermore, cancer cells were inoculated with or without fibroblast cell line (CCD-27Sk) into nude mice to clarify whether fibroblasts influence tumor-take and growth rates.
The results were as follows:
1) MKN 28 cells alone and MKN 45 cells alone showed a high tumor-take with 2f×10⁷ and 2×10⁶, but showed a low tumor-take with 2×10⁵.
2) The addition of 2 × 10⁶ CCD-27Sk cells to 2×10⁵ MKN 45 cells increased the low tumor-take number (17%) to 79%, and decreased the delay between cell inoculation and tumor appearance.
3) EGF was located in the cytoplasm of MKN 28 cells, MKN 45 cells and fibroblasts and in the endothelium of the capillaries surrounding them.
4) Fibroblasts located ALP were observed in stroma with the advance of tumor growth of MKN 28 cells and MKN 45 cells. The above results suggest that EGF production by gastric cancer cell(s) and its paracrine influence(s) on fibroblasts are necessary for the growth of gastric cancer cell(s).

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1) Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai
2) Department of Microbiology and Immunology, Nippon Medical School, Tokyo
3) Central Virus Diagnostic Laboratory, National Institute of Health, Japan, Tokyo
4) Department of Microbiology, Institute of Public Health, Tokyo
5) Department of Family Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai
6) Department of Pediatrics, McCormick Hospital, Chiang Mai
7) Department of Pediatrics, Faculty of Medicine, Chiang Mai University, Chiang Mai

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