• The Korean Journal of Zoology
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• v.20 no.2
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• pp.109-122
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• 1977

Ultraviolet irradiation of the vegetal hemisphere of the fertilized frog egg prior to first cleavage resulted in alterations in neural morphogenesis. The sensitivity to UV irradiation dropped drastically at the point of 2/3 time lapse between fertilization and the appearance of the first cleavage furrow. Scannining electron micrographs revealed a decrease in size of the cells on the surface of the irradiated embryos. However, ectoderm exchange frafts indicated that the ectoderm of the irradiated embryo retains its capaciiy to form a completely normal neural morphology and epidermal surface. These facts were interpreted in terms of a decrease in the capacity for invagination during gastrulation, and subsequent primary embryonic induction.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.709-727
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• 2001

The pattern of programmed cell death(PCD) has been examined during the early developmental period of development in mouse embryos, from embryonic day 4.5(E4.5) to E11.5 Embryos from Balb/c breedings were harvested at various embryonic stages between E4.5 and El1.5. Cell death was analysed by in situ terminal deoxynucleotidyl transferase mediated dUTP nick end labeling(TUNEL) staining in tissue sections and whole embryos. At the blastocyst stage(E4.5), a very few apoptotic cells were found in the inner cell mass of the blastocyst. In the early egg cylinder stage(35.0-5.5), a few apoptotic cells were detected in the embryonic ectoderm, the embryonic endoerm and the proamniotic cavity. In the advanced egg cylinder stage(E5.5-6.5), TUNEL-posifive cells were observed in the extra-embryonic ectoderm and extra-embryonic endoderm as well as in the embryonic ectoderm, embryonic visceral endoderm and proamniotic cavity. In the streak stage(E6.75-7.75), many TUNEL-positive cells were found in the ectoplacental cone. In contrast, only very few apoptotic cells were found in the chorion and extra-embryonic endoderm in extra-embryonic regions. In intra-embryonic region, a few apoptotic cells were randomly found in the embryonic ectoderm, mesoderm and visceral endoderm. At the early somitogenesis stage(E8.0-8.5), most apoptotic cells were observed in the most cranial portion of neural fold (neural ectoderm and adjacent ectoderm). At the mid somitogenesis stage(39.0-9.5), the otic placode first showed TUNEL-positive at this stage. Small number of TUNEL-positive cells were also first seen around optic placode and branchial arches. Three streams of TUNEL-positive cells were clearly seen in the cranial region at 59.5-9.75. At E10.5, apoptotic cells were localized in the developing eye, the junctional portion of medial nasal, lateral nasal and maxillary processes, the lateral portion of branchial arches, the junction of bilateral mandibular processes, and apical ectodermal ridges of limb buds. At E11.5, apoptotic cells were noticeably decreased in most area, except the developing limbs and several somites in the tail region. In this study, the global temporospatial pattern of PCD throughout early development of mouse embryos was discussed. It may provide the basis for further studies on its role in the morphogenesis of the embryo.

• Korean Journal of Bronchoesophagology
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• v.5 no.1
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• pp.90-95
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• 1999

Dermoids are rare disease which arise during embryogenesis. They are the most common variety of teratomas occurring in the head and neck region and most arsies in the nasopharynx or oropharynx. They are invariably benign and derived from only two germinal layers, ectoderm and mesoderm. They usually present as repiratory distress and swallowing difficulty at or soon after birth. Treatment consists of surgical resection. We recently experienced a case of a neonatal nasopharyngeal dermoid which led to severe airway obstruction and feeding difficulty and necessitated the endotracheal intubation.

• Molecules and Cells
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• v.44 no.10
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• pp.723-735
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• 2021

Spemann organizer is a center of dorsal mesoderm and itself retains the mesoderm character, but it has a stimulatory role for neighboring ectoderm cells in becoming neuroectoderm in gastrula embryos. Goosecoid (Gsc) overexpression in ventral region promotes secondary axis formation including neural tissues, but the role of gsc in neural specification could be indirect. We examined the neural inhibitory and stimulatory roles of gsc in the same cell and neighboring cells contexts. In the animal cap explant system, Gsc overexpression inhibited expression of neural specific genes including foxd4l1.1, zic3, ncam, and neurod. Genome-wide chromatin immunoprecipitation sequencing (ChIP-seq) and promoter analysis of early neural genes of foxd4l1.1 and zic3 were performed to show that the neural inhibitory mode of gsc was direct. Site-directed mutagenesis and serially deleted construct studies of foxd4l1.1 promoter revealed that Gsc directly binds within the foxd4l1.1 promoter to repress its expression. Conjugation assay of animal cap explants was also performed to demonstrate an indirect neural stimulatory role for gsc. The genes for secretory molecules, Chordin and Noggin, were up-regulated in gsc injected cells with the neural fate only achieved in gsc uninjected neighboring cells. These experiments suggested that gsc regulates neuroectoderm formation negatively when expressed in the same cell and positively in neighboring cells via soluble factors. One is a direct suppressive circuit of neural genes in gsc expressing mesoderm cells and the other is an indirect stimulatory circuit for neurogenesis in neighboring ectoderm cells via secreted BMP antagonizers.

• The Journal of the Korean dental association
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• v.49 no.8
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• pp.472-477
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• 2011

Dermoid cyst is a benign neoplasm, so called by teratoma that is derived from both ectoderm and mesoderm during embryonic period. The majority of dermoid cysts are found in the ovaries and approximately only 7% of dermoid cysts are found in the head and neck. The growth of dermoid cysts in the floor of the mouth is considered a rare condition. We report one case of huge dermoid cyst in the floor of mouth suffered with double chin appearance and difficulty in pronunciation and respiration. The cyst was excised successfully only intra-oral incision. Clinical progress was uneventful and postoperative recovery excellent without recurrence.

• Biomedical Science Letters
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• v.12 no.4
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• pp.343-348
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• 2006

Drosophila Sog and vertebrate Noggin play important roles during development. They function as antagonists against BMP4 signaling and induce neural ectoderm during embryogenesis. They are also engaged in appendage formation by inhibiting BMP4 signaling during late development. To understand further functions of Sog, Supersog, which is a more potent form of Sog, and Noggin BMP4 antagonists during development, I performed the molecular genetic analysis using Drosophila embryogenesis and wing formation as assay systems. In cellular blastoderm embryos, Sog inhibited Dpp signaling, Drosophila BMP4 signaling, whereas Supersog or Noggin did not block Dpp signaling. During wing formation, Sog inhibited Sax type I receptor of Dpp signaling whereas Noggin inhibited Tkv type I receptor of Dpp signaling. However, Supersog inhibited both Sax and Tkv type I receptors. These results suggest that functions of BMP4 antagonists are developmental stage dependent and indicate that each BMP4 antagonist inhibits BMP4 signaling by blocking different BMP4 receptors.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1110-1116
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• 2002

The skin(皮膚) separates epidermis(皮) and dermis(膚) in Oriental medicine. epidermis and hair come from ectoderm as dermis comes from mesoderm in embryology. Epidermis and hair belong to the Metal(金) and dermis belongs to the Earth(土) in Oriental medicine. The lung is related to the skin and hair. The skin surface is nourished by the essence from the lung, and the. lung has the function of sending wei-qi(衛氣.: defensive Energy) to the skin surface to guarantee body resistance. The skin takes nourishment from blood(血) and express by qi(氣). The supply of nutrients to the lung and skin relies on the function of the spleen, pancreas and subcutis. Flaming of the heart fire may scorch the essence of the lung-metal, inducing dermatosis.

• BMB Reports
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• v.50 no.10
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• pp.487-495
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• 2017

Mammalian inner ear comprises of six sensory organs; cochlea, utricle, saccule, and three semicircular canals. The cochlea contains sensory epithelium known as the organ of Corti which senses sound through mechanosensory hair cells. Mammalian inner ear undergoes series of morphogenesis during development beginning thickening of ectoderm nearby hindbrain. These events require tight regulation of multiple signaling cascades including FGF, Wnt, Notch and Bmp signaling. In this review, we will discuss the role of newly emerging signaling, FGF signaling, for its roles required for cochlear development.

• Korean Journal of Head & Neck Oncology
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• v.25 no.2
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• pp.160-162
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• 2009

Dermoid cysts are benign neoplasm that is derived from both ectoderm and mesoderm. They may be found at various sites of the body, but are extremely rare to occur in the lower neck. We present the case of a 22-year old woman with a midline cystic mass anterior to the cervical trachea. The mass was excised under local anesthesia. Histopathologically the diagnosis was confirmed as a dermoid cyst.

• Journal of Sasang Constitutional Medicine
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• v.21 no.1
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• pp.53-62
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• 2009

1. Objectives The purpose of this study is to find the ground why constitution must be classified into 4 types. 2. Methods I analysed the basic presuppositions to class 4 Type Constitution in Sasang Constitutional Medicine(SCM). And I connected the presuppositions with other theories from the viewpoint of directional properties of human body. 3. Results and Conclusions The most important presupposition to class 4 Type Constitution and apply to clinical therapy in SCM is that there is native strength and weakness of lung's Exhale Dispersing Qi, liver's Inhale Gathering Qi, spleen's Ascending Yin Qi and kidney's Descending Yang Qi. If there is superior tendency of Qi flow direction in human body, 6 directions(upward, downward, forward, backward, outward and inward) will be remarkable. But, in embryonic period, the outer skin is originated from the back(ectoderm) and the alimentary canal is from the front(endoderm). Therefore 4 directions(upward, downward, outward and inward) will be more remarkable, and those directions are included in the former presupposition.