• Applied Microscopy
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• v.23 no.1
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• pp.56-76
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• 1993

To investigate the histogenesis of tracheal epithelium in Sprague-Dawley strain rat, the author has used the fetal rats at the 16th, 18th, 20th and 22nd prenatal day and neonatal rats at the 1st and 7th day as well as rats at age of 5, 10 and 15 weeks after birth as experimental animals. Specimens were double stained with uranyl acetate and lead citrate for electron microscopic study. The results obtained were as follows; 1. At the 16th day of gestational age, ciliated cells were found in tracheal epithelium and light and dark ciliated cells possessing numerous mitochondria and smooth endoplasmic reticulum in the cytoplasm at the 22nd day of gestational age of the rat are observed. 2. At the 16th day of gestataional age, basal cells lying upon the basement membrane and having large numbers of glycogen particles in the cytoplasm, were found and at the 22nd day of gestational age, basal cells possessing numerous polysomes in the cytoplasm were observed. 3. At the 20th gestational age of the rat, microvillous cells possessing many rough endoplasmic reticulum and mitochondria as well as microvilli protruding into the lumen were found in tracheal epithelium. 4. At the 5th week after birth brush cell having profound filamentous strands and many pinocytic vesicles in the cytoplasm, was visible in the tracheal epithelium. 5. At the 15th week after birth large proportions of tracheal epithelium were lined with ciliated cells. Cosequently it is suggested that pseudostratified ciliated columnar epithelium was differentiated at the 16th day of gestational age, in addition cytoplasmic organelles of the microvillous and basal cells were matured at the 20th and 22nd gestational age, respectively and most of the part of the tracheal epithelium was lined with ciliated cells at the 15th week after birth.

• Animal cells and systems
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• v.6 no.3
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• pp.247-252
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• 2002

The effect of paraquat (PQ, 1,1＇-dimethyl-4,4＇-bipyridium) on the histogene-sis and glycoconjugates (GCs) properties of the pyloric region of the stomach in a perinatal rat was examined by histological and histochemical methods. Oral administration of PQ (9 mg/kg per day in 0.2 mL of D.W.) on 7 to 14 days of gestation revealed growth retardation with significant reductions in the length of pyloric gland and their pit. As for histochemical properties of GCs in the pyloric region of the stomach, the PQ-treated rats showed some differences, such as delayed initial appearance of the sulfated GCs and lectin affinities compared with the vehicle group. These different GCs properties in the surface and gastric pit were usually detected in the fetal rats and more prominent and evident differences were revealed in the gland epithelium of the early postnatal rat. These results suggest that maternal PQ administration causes intrauterine growth retardation asso-ciated with delayed histogenesis and GCs immaturation of pyloric mucosa in developing rat.

• Journal of Korean Neurosurgical Society
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• v.30 no.6
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• pp.786-789
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• 2001

Alveolar Soft Part Sarcoma(ASPS) is a rare entity that invariably ends in death from the disseminated disease. Although the most common site of metastasis is the lung, the central nervous system is also the third common site. Its histogenesis remains to be unknown and the gold standard treatment is radically surgical removal of the mass. However, adjuvant chemotherapy and radiotherapy are known to be less effective. The authors present a 24-year-old man who was admitted with headache and neck discomfort. Magnetic resonance( MR) imaging scans demonstrated multiple masses in the left frontal lobe, parietal lobe, and right cerebellum. The patient underwent surgery to remove multiple masses in the staged fashion. The postoperative course was uneventful, but the patient committed suicide 5 months later. The authors reviewed the pertinent literature and discussed this clinical entity with references.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.6
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• pp.533-537
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• 2010

Sialadenoma papilliferum (SP) is a rare benign neoplasm that normally arises from the minor salivary glands, particularly in the palate. SP is normally encountered in older men with an exophytic papillary surface growth. In the present study, an SP of the hard palate of a 69-year-old woman was examined immunohistochemically. Myoepithelial cell markers, such as S-100, smooth muscle actin and vimentin, were observed in the basal or luminal layer of tumor cells, indicating that myoepithelial cells participate in the pathogenesis of SP. In addition, cytokeratin 7 was also strongly detected in the tumor cells, suggesting that excretory ductal epithelial cells have a role in its histogenesis. A review of the literature of immunohistochemical studies on SP showed that the expression and co-expression of cytokeratins and myoepithelial cell markers have been reported in tumor cells. These results suggested that excretory duct cells and myoepithelial cells participate in the pathogenesis of SP.

• Development and Reproduction
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• v.17 no.3
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• pp.179-186
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• 2013

Neural stem cells are found in adult mammalian brain regions including the subgranular zone (SGZ) of the dentate gyrus (DG) and the subventricular zone (SVZ). In addition to these two regions, other neurogenic regions are often reported in many species. Recently, the subcallosal zone (SCZ) has been identified as a novel neurogenic region where new neuroblasts are spontaneously generated and then, by Bax-dependent apoptosis, eliminated. However, the development of SCZ in the postnatal brain is not yet fully explored. The present study investigated the precise location and amount of neuroblasts in the developing brain. To estimate the importance of programmed cell death (PCD) for SCZ histogenesis, SCZ development in the Bax-knockout (KO) mouse was examined. Interestingly, an accumulation of extra neurons with synaptic fibers in the SCZ of Bax-KO mice was observed. Indeed, Bax-KO mice exhibited enhanced startle response to loud acoustic stimuli and reduced anxiety level. Considering the prevention of PCD in the SCZ leads to sensory-motor gating dysfunction in the Bax-KO mice, active elimination of SCZ neuroblasts may promote optimal brain function.

• Journal of Educational Research in Mathematics
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• v.12 no.3
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• pp.409-424
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• 2002

The historico-genetic principle has been advocated continuously, as an alternative one to the traditional deductive method of teaching and learning mathematics, by Clairaut, Cajori, Smith, Klein, Poincar$\'{e}$, La Cour, Branford, Toeplitz, etc. since 18C. And recently we could find various studies in relation to the historico-genetic principle. Lakatos', Freudenthal's, and Brousseau's are representative in them. But they are different from the previous historico- genetic principle in many aspects. In this study, the previous historico- genetic principle is called as classical historico- genetic principle and the other one as modern historico-genetic principle. This study shows that the differences between them arise from the historical views of mathematics and the development of the theories of mathematics education. Dewey thinks that education is a constant reconstruction of experience. This study shows the historico-genetic principle could us embody the Dewey's psycological method. Bruner's discipline-centered curriculum based on Piaget's genetic epistemology insists on teaching mathematics in the reverse order of historical genesis. This study shows the real understaning the structure of knowledge could not neglect the connection with histogenesis of them. This study shows the historico-genetic principle could help us realize Bruner's point of view on the teaching of the structure of mathematical knowledge. In this study, on the basis of the examination of the development of the historico-genetic principle, we try to stipulate the principle more clearly, and we also try to present teaching unit for the logarithm according to the historico- genetic principle.

• Journal of Yeungnam Medical Science
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• v.1 no.1
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• pp.199-206
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• 1984

With respect to the histogenesis of the neurofibroma, there are many controversies, since von Recklinghausen postulated that neurofibromas are mainly fibrous tumors arising from the connective tissue of the nerve sheaths. According to the recent studies through the electron microscope, the neoplastic perineurial cells are regarded as the main components of the tumor. So, the neurofibroma enucleated from the median nerve at the level of proximal arm without resulting neurologic sequale was examined through the light- and electron microscope. Ultrastructurally, this tumor is composed of the perineurial cells, fibroblasts, and collagen fibers. The predominant perineurial cells show distinct basal lamina, and contain abundant microfilaments.

• The Korean Journal of Cytopathology
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• v.6 no.1
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• pp.71-75
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• 1995

A fine needle aspiration biopsy specimen of a retroperitoneal mass in a 26-year-old man who had had an orchiectomy for seminoma was submitted for cytologic evaluation. Cytologic features of the specimen included uniform neoplastic cells found singly or in groups of several cells intermingled with lymphocytes in a characteristic foamy, lacelike background. These cells varied from 10 to 20 m in diameter. The nuclei were round to ovoid with fine or reticular chromatin and one or more prominent nucleoli. The poorly defined cytoplasm stained pale-blue or blue with cytoplasmic vacuoles. The cytologic appearance was consistent with seminoma. Documented reports of the cytological appearance of seminoma are rare. The diagnosis of primary gonadal seminoma by fine needle aspiration biopsy is probably not indicated since the treatment of a primary gonadal tumor, regardless of its histogenesis, requires surgical resection. However, fine needle aspiration biopsy is extremely valuable in the diagnosis of extragonadal as well as metastic and recurrent seminoma.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.408-412
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• 1999

Since sclerosing hemangioma of the lung was first described by Liebow and Hubbell in 1956, there have been several reports on cases occurring as a solitary nodule; however, sclerosing hemangiomas occurring as multiple nodules are extremely rare. The histogenesis of this tumor remains controversial and there are several hypotheses of the etiology. Three separate nodules were found in a 57-year-old housewife, one found in the right middle lobe, one in the apicoposterior segment of the left upper lobe, and one in the superior segment of the left lower lobe. The only symptom or sign presented was a dry cough. Apicoposterior segmentectomy of the left upper lobe and wedge resection of the superior segment of the left lower lobe were performed. The postoperative course was uneventful and the patient was discharged on the postoperative 15th day.

• Journal of Yeungnam Medical Science
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• v.16 no.1
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• pp.108-113
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• 1999

Clear cell sarcoma is a rare soft tissue sarcoma that occurs in tendons and aponeuroses, usually in the lower extremities in young adults. The exact histogenesis is not definitely established. We experienced a case of 58 year-old female who presented with a $3.2{\times}2.2cm$ sized mass located in the subcutaneous tissue of the left lower thigh. The mass was well-circumscribed, grayish and firm. Two small satellite nodules were also seen. Histrionically, the tumor was composed of round to fusiform cells with clear or pale eosinophilic cytoplasm and separated into compact nests or short fascicles by delicate fibrous septa. The melanin pigments and hemosiderin were seen. Tumor cells showed positive reaction for S-100 protein and HMB-45. The ultrastructural examination showed abundant mitochondria and melanosomes.