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Biomedical subjects

H Okamura

Publications and source records attributed to H Okamura.

At least 703 records · Page 39Linked to original sources
PubMed1984

[A light and electron microscopic studies of müllerian adenofibroma of the uterus].

Müllerian adenofibroma composed of both histologically benign epithilia and benign mesenchyme is considered to be a rare entity of mixed müllerian tumor. A case of müllerian adenofibroma of the uterus was studied by light and electron microscopy. Light microscopically, the cleft-like glands lined by single-layered columnar or cuboidal epithelial cells were distributed in the proliferation of surrounding fibroblast-like mesenchymal cells. Mitotic figures of mesenchymal cells were less than 1--2 in 10 high power fields, and no nuclear atypia or heterologous elements were observed. Electron microscopically, the epithelial cells had well-developed mitochondria, r-ERs, tonofilaments in the cytoplasm, and short microbilli or cilia protruding into the lumen. In the mesenchyme, two types of cells were observed. One was spindle-shaped cells resembling fibroblasts, and the other was cells resembling immature smooth muscle cells. The histological and ultrastructural features of müllerian adenofibroma were felt to resemble those of müllerian adenosarcoma, which may pursue a clinically malignant course. These findings suggest that müllerian adenofibroma and adenosarcoma may be in the common spectrum of mixed müllerian tumor.

Adenofibroma↗
PubMed1984

[A histochemical study of the respiratory system in rabbit ovarian follicles during ovulation].

Histochemical studies on the activities of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), succinate dehydrogenase (SDH) and cytochrome oxidase (CY-O) in rabbit ovarian follicles at various times after the administration of hCG were performed to investigate the relationship between the activities of steroid biosynthesis and the respiratory system. The activities of 3 beta-HSD and SDH were studied by using the tetrazolium salt and CY-O activities by the method of Seligman with prefixation. On the granulosa cell layer prior to the administration of hCG, no activities of 3 beta-HSD and CY-O were detectable, while slight activities of SDH were observed. These three enzymes showed intense activities on the granulosa cell layer 3 hours after the administration of hCG, which were maintained till the time of ovulation. The results indicated that increased activities of steroid biosynthesis in the granulosa cell layer after LH-surge were accompanied by the accelerated TCA cycle and respiratory chain. Energy from accelerated glycolysis may be utilized for steroid biosynthesis in preovulatory granulosa cells. Increased O2 consumption due to accelerated aerobic glycolysis is in accordance with hyperactivity of perifollicular capillaries, which finally leads to rapid follicular expansion and ovulation.

Animals↗
PubMed1984

Development of smooth muscle in the human fetal uterus: an ultrastructural study.

Prenatal development of uterine smooth muscle was studied by light and electron microscopy in specimens obtained from ten human fetuses between 12 and 40 weeks gestation. Light microscopical observation of transverse sections of the body of the uterus revealed that the outer, subserosal layer of elongated cells was distinguishable from 14 weeks. This layer was more cellular than the inner layer and increased its thickness with advancing age. Ultrastructurally, the mesenchymal cells of the uterus did not contain myofilaments until 16 weeks. At 18 weeks, however, spindle shaped cells in the outer layer had a few filaments with dense bodies and well developed organelles and were identified as immature smooth muscle cells. By 31 weeks, the cells in this layer developed into almost mature smooth muscle cells, which contained abundant cytoplasmic filaments, dense plaques and surface vesicles along the cell membrane, and an external lamina. Therefore, in the human fetal uterus, smooth muscle differentiation begins at about 18 weeks and myometrium is formed in the outer layer of the wall by 31 weeks gestation. In the inner layer of the uterus that corresponds to the endometrial stroma, in addition to fibroblast-like cells, there were cells with plump cytoplasm which contained well developed granular endoplasmic reticulum and Golgi apparatus and which were identified around blood vessels by 26 weeks. These features resembled those of predecidual cells, and suggested the influence of sex steroids on the human fetal uterus.

Cell Differentiation↗
PubMed1984

[Histogenetic considerations of experimentally induced adenomatoid tumor-like nodules produced by sex steroids].

Glandlike structures with intervening fibrous stroma were observed in about 20% of subperitoneal nodules produced in the abdominal cavities of guinea pigs treated with various doses of estradiol benzoate (E) for 3 months. These glandlike structures were composed of cells resembling mesothelium, ciliated cells, cells with mucin in the cytoplasm and cells with a squamous appearance. Glandlike structures similar to those following estrogen treatment alone were also observed in about 20% of the nodules produced in the guinea pigs by pre-treatment with E and followed by combination treatment with E and progesterone (P) for 1 to 3 months. However, the glandlike structures were composed only of cells resembling mesothelium and cells with cilia. Both of these glandlike structures resembled adenomatoid tumors. We therefore conjecture that the formation of gland-like structures in the subperitoneal nodules is the result of mesothelial inclusions and their proliferation, and that some of these mesothelial cells were differentiated into ciliated, mucinous and squamous cells by estrogen.

Abdominal Neoplasms↗
PubMed1984

Scanning electron microscopy study on corrosion cast of rat uterine vasculature during the first half of pregnancy.

Vascular changes in the rat uterus during the first half of pregnancy were studied by the microcorrosion casting/scanning electron microscope method. Arterioles supplying the endometrium were divided into two groups according to differences in their shape, distribution, and development. Circular impressions indicative of the presence of vascular sphincters were observed around the casts of each group of arterioles. Resin leakage, suggesting an increase in vascular permeability, was observed from capillaries composing the sub-epithelial plexus and the glandular 'baskets'. Although leakage was noted throughout the endometrium before implantation, it tended to be localised around each blastocyst after the onset of implantation. The present results suggest the existence of a special control mechanism of the uterine blood flow, and that the uterine vasculature is affected by the conceptus from the beginning of implantation.

Animals↗
PubMed1983

Coexistence of dopamine and neurotensin in hypothalamic arcuate and periventricular neurons.

The coexistence of dopamine and neurotensin in the same neuronal perikarya in the arcuate nucleus of the rat hypothalamus was examined by combined fluorescence histochemistry and immunohistochemistry on the same tissue sections and we obtained the evidence of the coexistence of two substances. The functional significance of those two substances for the prolactin release from the anterior pituitary was also briefly discussed.

Animals↗
PubMed1983

Adenomatoid tumor--like structures in the subperitoneal nodules produced by sex steroids.

Multiple subperitoneal nodules were produced in the abdominal cavities of guinea pigs treated with various doses of estradiol benzoate for 3 months. Gland-like structures with intervening fibrous stroma were observed in 20% of these nodules. These gland-like structures resembled adenomatoid tumors, but were composed of cells that resembled mesothelium, ciliated cells, and cells with mucin in the cytoplasm. Some parts were composed of cells that had a squamous appearance. In guinea pigs, pretreatment with estradiol benzoate followed by treatment with a combination of estradiol benzoate and progesterone for 1 to 3 months produced nodules with gland-like structures similar to those produced by estrogen treatment alone. However, the gland-like structures were composed only of cells that resembled mesothelium and cells with cilia. Therefore, we conjecture that the formation of gland-like structures in the subperitoneal nodules is the result of mesothelial inclusions and their proliferation and that some of these mesothelial cells were differentiated into ciliated, mucinous, and squamous cells by estrogen.

Adenoma↗
PubMed1983

Some cellular characteristics of somatostatin neurons and terminals in the periventricular nucleus of the rat hypothalamus and median eminence. Electron microscopic immunohistochemistry.

Somatostatin neuronal perikarya and their processes, presumably dendrites, in the periventricular nucleus of the rat hypothalamus and terminals in the median eminence were observed by electron microscopic immunohistochemistry. Neuronal perikarya and processes contained immunoreactive dense granules (100-120 nm in diameter) and other cellular components such as polysomes, rER membranes occasionally showed high electron density. Few axo-somatic terminals were found on the somatostatin neurons, but we could detect a number of preterminal axons on immunoreactive processes, presumably dendrites. Therefore, we considered that somatostatin neurons receive mainly neuronal input through axo-dendritic synapses rather than through axo-somatic ones. In the somatostatin terminals in the external layer of the median eminence immunoreactivity was completely restricted on the granules.

Animals↗
PubMed1983

VIP (vasoactive intestinal polypeptide)-like immunoreactive amacrine cells in the retina of the rat.

Vasoactive intestinal polypeptide (VIP)-like immunoreactivity was demonstrated in the rat retina, using the peroxidase anti-peroxidase (PAP) method. VIP-like immunoreactivity was observed in the cytoplasm of amacrine cells of the inner nuclear layer (INL) and their varicose processes ramifying in the inner plexiform layer (IPL). VIP-like immunoreactive amacrine cells were present in both central and peripheral retinal regions. In some sections fine ramifications of varicose processes in the IPL could be clearly traced. VIP-like immunoreactivity was detected in both 'stratified' and 'diffuse' amacrine cells. VIP-like immunoreactive amacrine cells were classified into four types.

Animals↗
PubMed1983

Palliative urinary diversion in patients with advanced cervical cancer.

An analysis of 25 palliative urinary diversions for advanced cervical cancer is presented. The median postoperative survival was 176 days and the mean was 329 days. Indication, methods of surgical procedure and duration of known disease did not strongly influence survival. The patients who were treated with radiation therapy after urinary diversion had a longer median survival. Renal function returned to normal in 7 of 9 azotemic patients. 41% of the patients left the hospital and this group subsequently spent 62% of their remaining survival at home. Guidelines for selection of the patients who might benefit from urinary diversion are discussed.

Adult↗
PubMed1983

Hysteroscopic diagnosis of malignant mixed müllerian tumor of the corpus uteri.

Hysteroscopic findings of two cases with homologous type of malignant mixed müllerian tumor of the corpus uteri are described. On hysteroscopic examination, not only were nodular or polypoid lesions with fairly smooth surfaces found but also lesions with rough uneven surfaces and dilated vessels resembling the figures of endometrial carcinoma were observed. The blood vessels of lesions with fairly smooth surfaces were not dilated. Under hysteroscopy, each lesion with a smooth surface seemed to be more closely related to a benign lesion, such as an endometrial polyp or submucous myoma. The lesions with smooth surfaces corresponded to the histologically sarcoma-dominant areas and the lesions with uneven surfaces and dilated vessels were equivalent to the sites where adenocarcinoma was noted. Thus, hysteroscopic findings of this tumor well reflected the histology near the surface of the endometrium.

Endoscopy↗
PubMed1983

Time of vasopressin neuron origin in the mouse hypothalamus: examination by combined technique of immunocytochemistry and [3H]thymidine autoradiography.

A time-course study on production of vasopressin neurons (VP-neurons) in the mouse hypothalamus was carried out by application of [3H]thymidine autoradiography and PAP-immunocytochemistry simultaneously on the same tissue sections. In the paraventricular nucleus (PVN) and the supraoptic nucleus (SON), heavily [3H]thymidine-labeled VP-neurons were detected only in the specimens of the animals exposed to the isotope on the gestational day 12. While in the suprachiasmatic nucleus (SCN), heavily isotope-labeled VP-neurons were observed in the specimens of the animals exposed to the isotope on the gestational day 12 or day 14. Therefore, the production of the VP-neurons in the SCN is prolonged and slightly more delayed than that in the SON or PVN.

Animals↗
PubMed1983

Distribution of the VIP-like immunoreactive neurons in the cat central nervous system.

Immunohistochemical topographic localization of the vasoactive intestinal polypeptide (VIP)-like immunoreactive neurons in the cat brain was investigated using a peroxidase anti-peroxidase technique. VIP-like immunoreactive neurons were mainly localized in the cerebral cortex, limbic cortex, hypothalamic nuclei; suprachiasmatic nucleus, supraoptic nucleus, paraventricular nucleus, periventricular nucleus and arcuate nucleus, and in the midbrain; such as the central grey and the raphe nucleus. It was demonstrated that VIP-like immunoreactive neurons were widely distributed in the cat brain, particularly in the hypothalamus, compared with those of the rat and mouse; though whether these differences were species-related or due to differences in the physiological conditions remains to be determined. This is the first report of VIP neuronal perikarya in the arcuate nucleus of mammalian species, although these cells are present in the arcuate nucleus of birds.

Animals↗