In order to elucidate biosynthetic process of large ribosomal subunits, we have isolated precursor particles from rat liver nucleoli by stepwise extraction with 50mM Na acetate buffer(pH5.5)-25 mM KC1-50pg DNase followed by 50 mM Tris-HCI buffer(pH7.4)-25 mM KCI both in the presence of 0.1% PVS and 1% Brij 98. These extracts were further fractionated by sucrose density gradient centrifugation into four snbfractions: a, b, c and d, which cover the two broad peaks in 60S and 80S region. RNA species of each fraction were characterized by poly-acrylamide gel electrophoresis and sucrose density gradient centrifugation and the particles in each fraction were observed by electron microscopy using shadow casting technique. Comparison of RNA species present with shape distribution of the particles in each fraction suggests that the maturation process of the ribosomal large subparticles could be schematized as follows: Filamentous molecules(contain predominantly 45S RNA)rod like molecules(probably contain 35S RNA) →spherical particles(contain →2 8S RNA) → Mature ribosomal large subparticles. Maturation process of ribosomal particles may involve, in addition to the so called sequential cleavage of RNA, folding of loose ribonucleoprotein filaments into compact spherical large subparticles.

View full abstract

Virgin female mice of two strains; 67 of C₃H/He strain and 43 of ddY-F stain, were classified to the following four groups. ( 1 ) DMBA-injected; Both 20 C3H and 11 dd mice aged 6-7 weeks were injected into a caudal vein with a single dose,2.5 mg, of 7,12dimethylbenz (α) anthracene (DMBA). (2) Ovariectomized; Each 10 C3H and dd mice were ovariectomized at the age of 6-7 weeks. (3) Combination-treated; Both 24 C₃H and 13 dd mice were recieved with a bilateral ovariectomy at the age of 6-7 weeks and injected by 2.5 mg of DMBA 2 days later. (4) Control, untreated; Either 13 C3H or 9 dd mice were used. On these mice aged more than 30 weeks, several morphologic investigations were performed. The results are as follows.
I. Any adrenocortical tumors could not be found on the control, untreated mice aged even more than 72 weeks. But, so-called subcapsular cell reaction was detected already in almost all adrenal cortices over 30 weeks of age. The reaction was more in C₃H mice than in dd mice. The reaction, in general, was accerelated with aging and by the above mentioned treatments. It is supposed ultrastructurally that the proliferating subcapsular cells would be developed from the immature mesenchymal cells in this region.
II. Incidence of the adrenocortical tumor on the DMBA-injected group was 3/20 in C₃H mice and 1/11 in dd mice, respectively. All tumors were microscopically composed of Type A cell adenoma. The tumors looked to be adenomatous subcapsular cell reactions. Histological pattern of the target organs(uterus, vagina, kidney and submaxillary gland) of the mice bearing Type A cell adenoma could indicate that the tumor cells might not secret any hormones.
III. Ovariectomy at the age of 6-7 weeks induced a diffuse hyperplasia in the bilateral adrenal cortices. The hyperplasia was detected prominently on all C₃H mice aged over 25 weeke, but it showed less incidence and variable grade on the aged dd mice. Microscopically, the change developed from the inner zone of the adrenal cortex to the capsule, and it was mainly composed of large, round clear cell, Type B cell. Type b cell (immature Type B cell) could be identified ultrastructurally from Type B cell in the so-called Type B cell hyperplasia, and both hyperplastic cells were resemble to either the inner fasciculata or the reticularis cells. The histologic patterns of the target organs of the mice bearing so-called Type B cell hyperplasia were mainly male type, but those of few mice were female or intermediate type. Unilateral adrenocortical tumor was detected on the ovariectomized group (2/10 in C3H mice and 1/10dd mice), and all tumors had the similar appearance to cystic follicular type of the ovarian granulosa cell tumor. Prominent endometrial hyperplasia could be observed on the ovariectomized mice bearing such adrenocortical tumors.
IV. On the combination-treated group,5 adrenocortical tumors could be found only in C₃H mice. Administration of the carcinogen immediatedly after the gonadectomy could not potentiate the adrenocortilcal tumorigenesis in the female mice. Ultr astructural appearance of the induced tumor was Type A cell adenoma in 3 mice having no hyperhormonal findings, and mixed type adenoma in 2 mice, respectively. The latter was composed of adenomatous Type B cell proliferation and tubular arrangement of other cells (the author's Type a cell), and it might secret some sex hormones.
V. Brown degeneration was observed in almost all examined m ice aged more than 30weeks, and the change was more dominant in dd mice than in C₃H mice. The pigment granules, which were identified to lipofuscin histochemically, were accumulated mainly in the hypertrophic histiocytes and few in the degenerative reticularis cells. In conclusion, DMBA could not induce a neoplastic transformation in the mature, reactive adrenocortical cells,

View full abstract

An electrophysiological study was made of rabbits as to relations between uterine movement and the activity of the central nervous system with the following results:
1. Following 100Hz stimulation of the brain stem reticular formation, there appeared arousal reaction in EEG and evoked muscular discharge in the fore and hind limbs, accompanied by a marked acceleration of uterine movement.
2. The accelerated uterine movement accompanying aro usal reaction was abolished not by a destruction of the infundibulum, but by a transection of the spinal cord. Accordingly, it was considered that an accelerating impulse passing from the brain stem reticular formation to the uterus on appearance of arousal reaction was likely to work efferently.
3. Fro m the results of experimental destruction of the hypothalamus, the system which accelerated uterine movement was demonstrated to exist in the hypothalamus.
4. From the responses of various drugs to arousal reaction and ute rine movement, the system which accelerated uterine movement was subjected to inhibitory influence of the ascending reticular activating system.
5. Morphine and barbiturate were studied as to their actions on average afferent evoked potential developing in the cerebral cortex on stimulus of the uterus, and their results were found to be different from those responses to average afferent evoked potential due to stimulation of the sciatic nerve.
6. Spontaneous unit discharge was record ed with a microelectrode from the brain stem reticular formation and CM, and studies were made of influences of uterine stimulus on the recordings and the action of pentazocine used as an analgesic. As a result, recordings were obtained of unit discharge which was considered to respond to uterine pain. The ab ove data led to clarification that the nerve fibers that connect the central nervous system with the uterus were different in nature from those of the autonomic nervous system or the somatic nervous system and that, nevertheless, the same as long as pain itself was concerned.

View full abstract

In endocrine cytology which pursues change of female sex hormones, vaginal smear: by the Papanicolaou stain are employed to study chiefly the findings of squamous of the vagina on an integral basis. Of these findings the size of a nucleus constitute: a very important factor, which, however, seems to have been studied to subjectively, but scarcely taken up for a systematic, dimensional approach.
The establishment of standards for objective evaluat i on and dimensional determinatior has been recently emphasized, giving much credit to the importance of numerical data to be adopted as a parameter especially in autocytoscreening.
Regarding the autocytoscreening for cervic a l cancer, Dr. Yasuda, one of the author': colleagues, standardized nuclear diameter as 11μ to be used as a parameter. Here, it is desired to clarify whether his standardized value (11μ) is influenced by changed values of the squamous cell nucleus due to sex hormones. Indeed, few reports have beer made of a systematic, dimensional study of the size of the squamous cell nucleus due to change in sex hormones.
The present study was made with carefully selected nine mature women with a normal menstrual cycle, aged 28-38 years, at their mid follicular phase corresponding to the estrogen phase (the seventh day ± two days in menstruation), the ovulatory phase in the peak of the estrogen phase (the 14th day ± two days in menstruation), and the mid luteal phase corresponding to the progesterone phase following the estrogen phase (the 20th day ± two days in menstruation).
The vaginal smears at each phase were Papanicolaou stained; intermediate cell nuclei which apparently always appeared in vaginal smears and which were little affected by exogenous influence were statistically determined with an ocularmicrometer for their maximum, minimum, and average diameter maximum + minimum with the following results:
No. of nuclei max. diam. min. diam. average
Mid follicular phase 442 8.30 ± 1.30μ 7.15 ± 1.15μ 7.98 ± 1.19μ
Ovulatory phase 436 7.52 ± 1.39μ 6.62 ± 1.27μ 6.83 ± 1.25μ
Mid luteal phase 448 10.23 ± 1.27μ 9.26 ± 1.23μ 9.98 ± 1.16μ
A comparative study revealed that the data changed significantly at a 5 % leve l of significance. That is, nuclei were always shaped round or cylindric, but their size was slightly large at the mid follicular phase, becoming smallest at the ovulatory phase, and growing larger again to the largest at the mid luteal phase. However, even when enlarged they seldom exceeded the average 11μ. It was concluded that the establishment of over 11μi n diameter for the nucleus as an evaluating standard in the cytological diagnosis of cervical cancer seemed reasonable. It seems safe to state that any influence of sex hormones can be ignored so far as the nucleus diameter is concerned in determining malignant cells.

View full abstract