A method for the observation of cell division using acetic dahlia solution was introduced to lower secondary school science classes. Onion seeds with about 10 mm of the germinated portion could be stored in a refrigerator for at least one week in good condition for observing cell division. A staining temperature at 35°C resulted in a ten minute reduction compared to that of room temperature. These findings are useful for preparing specimens and observing dividing cells under a microscope in a limited time of lesson (50 min) in lower secondary schools.

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Germinated seedlings of Allium cepa are suitable material for observing mitosis because they are easy to grow in a short time, and for finding mitotic cells with a simple staining method. The mitotic index which indicate the frequency of mitotic cells in the root meristem with 5-10 mm of root lengh at 23°C usually was higher than that with other root length. Under this temperature, the roots of most seedlings reached to 5 - 10 mm long within 3 or 4 days. When the class schedule changes, it is necessary to adjust the condition of seedling containing many mitotic cells. The way of maintaining the condition of the seedling was through refrigeration and then removal from the refrigerator after some days for observation of mitosis. These experiences suggested the followings: The mitotic index depends on the root length and not the temperature, therefore there is no difference between low temperature (2 - 3°C) and room temperature (23°C). Under low temperature the seedlings grew slowly and the majority became 5 - 10mm for three weeks after sown. Their mitotic index was similar to the seedling grown 5 - 25 mm in room temperature, therefore we can make seedlings from the higher frequency of mitotic cells when we change the schedule of school experiments. The seed stored with silica gel in a paper envelope and enclosed in a plastic bag for five years in a refrigerator and the mitotic index was examined when their seedling is 1 - 25 mm.

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胃癌35例と大腸癌25例を対象として, 阻止法stathmokinetic methodにより両癌腫の癌能 (癌指数・癌指数比ならびに癌細胞産生率) を測定して対比するとともに, 種々の臨床病理学的所見との関連性を検討した.
癌能は癌径・深達度・stage・組織型など癌腫の状態で変化してことを示すと同時にcellkinectiesからみて両癌腫は癌腫として共通の現象が存在しているが, 胃癌は大腸癌よりも2.1～3.6 (平均2.9) 倍高い癌能を有していることを示した. この胃癌と大腸癌の癌能の差が両癌腫の悪性度や発育速度の差に関与している可能性について, 文献的に考察を加えた.

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The writer found an unexpected occurrence of univalent chromosomes in the microsporogenesis of rice-plant in the summer of 1934. Materials were collected from plants cultivated in the glass-house at the Plant Breeding Institute of the Hokkaido Imperial University, Sapporo. All of the three varieties examined showed the same abnormality, the frequency being approximately 40% in average. The fixation numbers given in the tables indicate the varieties used, and the dates on which the fixation was made, as follows :
Frequencies of asynaptic cells were counted in three following stages, diakinesis, prometaphase-I and the metaphase-I (Tables 1-4). It was found that the number of asynaptic cells in diakinesis suddenly decreased in prometaphase-I and again increased in metaphase-I.
At metaphase-I, the univalents scatter randomly on the spindle, but it was often observed that each two univalents lie in close proximity (Figs. 2, 3, 8, etc.).
Distribution of the univalents on the spindle was noted. Some of the univalents lie within the equatorial plate (Figs. 5, etc.), while the others scatter on the spindle. In the cells with two univalent chromosomes, the position of them was studied (Table 5), and it was found that the behaviour of the two univalents was not always at random. Data from Table 5 suggest that the univalents have a tendency to avoid entering the equatorial plate, and that when two univalents which are naturally homologous wander on the spindle, they are apt to take their position in the same side of the plate. These facts as the increase in the frequency of apparently normal cells at the first prometaphase where the repulsion force between chromosomes suddenly decreases, the tendency of each two univalents to lie in close proximity in the spindle and the tendency of two homologous univalents to be in the same side of the equatorial plate rather to lie in the different sides, all may be explained on one and the same hypothesis : the operation of an attractive force between the two homologous but unpaired univalents.
The reason why asynapsis is caused in this case is unknown. But it was suggested that it might have perhaps been caused by some environmental conditions. The genetic effect which sometimes brings about asynapsis seems not to be applicable in this case. It is the writer's great regret, however, to mention that his subsequent experiments failed to detect what the very cause may have been.
Most of the pollen grains were aborted. Fertility, too, was extremely low as shown below :
An extremely bad harvest of rice was recorded in 1934 all other the northern parts of Japan. Besides failure of micro- and macrosporogenetic cytokinesis under low temperatures which was found by the writer (Sakai 1937 a; b, 1939), the unexpected and the cause-unknown asynapsis described above might have played a certain role in the bad harvest of rice of that year.

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In order to reduce the adverse effects of anticancer drugs, the new dosage form comprised activated carbon particles (Mitsubisi#1500AA^R, specially prepared by Mitsubisi Chemical Industries Co., Ltd, Tokyo, Japan) adsorbing aclarubicin was devised. The new dosage form composed of aclarubicin and activated carbon particles ten times as weighty as aclarubicin in saline. The acute toxicity of the new dosage form(ACR-CH) injected intraperitoneally was studied in mice. The LD₅₀ value of ACR-CH was over 75mg/kg in terms of aclarubicin, otherwise that of aclaruhicin aqueous solusion (ACR-sol) was 32.9mg/kg by means of Litchfield-Wilcoxon's method. Pathological examinations of the animal' organs and examinations about body weight change and symptom of toxicity revealed no remarkable difference between ACR-CH and ACR-sol. Those results show no evidence of any addisional side effects of aclarubicin by the change of dosage form. We concluded that acute toxicity of aclarubicin was reduced by the use of activated carbon particles as a carrier.

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L. delbriickii No. 1はその生育とにビタミンB₁₂を要求するが,に必要な濃度は生長に要求する濃度の1,000倍以上であって,B₁₂濃度の低い場合(10^-5μg/ml)は殆ど起り得ずすべての細胞が異常に伸長する.異常に伸長した細胞はグラム陰性,クロマチン凝集を示し,通常の方法でprotoplastを生成させようとすると内部から溶菌を起し正常の細胞とは明かに異っている.更にビタミンB₁₂は相当多量菌体内に吸収保持されて活性を示していることがわかった.

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