Congenital dermal sinus (CDS) is a rare entity widely known to occur as a result of the of the failure of the neuroectoderm to separate from the cutaneous ectoderm during the process of neurulation at the third to fifth week of gestation. The lesion can occur at any level of the craniospinal axis, but are located predominantly at the lumbosacral and occipital region. CDS of thoracic region and cervical region are rare. The patient with CDS presents with meningitis and/or mass effect from the associated inclusion tumor. They are usually dermoid or epidermoid cyst. Teratoma is rarely associated with CDS. We report our experience of CDS an 11-month old boy associated with an intramedullary dermoid tumor at the thoracic region, and together we report a review of the literature.
Axis, Cervical Vertebra ; Dermoid Cyst ; Ectoderm ; Epidermal Cyst ; Humans ; Infant ; Male ; Meningitis ; Neural Plate ; Neurulation ; Pregnancy ; Spina Bifida Occulta* ; Teratoma

OBJECTIVE: Congenital dermal sinus is a rare congenital disease that results from the failure of the neuroectoderm to separate from the surface ectoderm during the process of neurulation, where there is communication between the skin and the deeper structures. Their pathogenesis, clinical course and treatment strategy are well known. We analyze our series and compare our results with other series. METHODS: Twenty patients were diagnosed as congenital dermal sinus and confirmed pathologically from October 1986 to July 2003 at our hospital. We studied the patients' clinical manifestations, radiological findings and pathological profiles. RESULTS: Seven cases were located in the suboccipital area and 13 cases were located in the spinal area. Interestingly, 4 of 13 spinal lesion cutaneous openings were located lower than the 3rd sacral body level. 8 of 20 lesions were terminated at neural structures, 4 of 20 lesions were terminated at the intradural portion and others terminated at the extradural portion. Nine anomalies were combined with the dermal sinus, including 4 lipomas, 2 Currarino's triad, 1 encephalocele, 1 myelomeningocele and 1 diastematomyelia. Eleven patients had dermoid tumors. CONCLUSION: Congenital Dermal Sinus must be surgically removed immediately if they are diagnosed. The surgical procedure of congenital dermal sinus is complete removal, but in some cases, complete removal is impossible. In those cases, we removed all epithelial tissues. We consider sacrococcygeal dimple almost invariably have no connection with intraspinal structures. But, if other cutaneous manifestations are combined with cutaneous pits, it can communicate with the sacrococcygeal dimple.
Dermoid Cyst ; Ectoderm ; Encephalocele ; Humans ; Lipoma ; Meningomyelocele ; Neural Plate ; Neural Tube Defects ; Neurulation ; Skin ; Spina Bifida Occulta*

In the rat, the neural plate appears at day 9 and the neural tube closes at day 10.3. During neurulation, the neuroepithelium is exposed directly to amniotic fluid and blood circulation begins at day 10.5. Accordingly, amniotic fluid may be an important source of nutrition for normal development of the nervous system. Among many different components of amniotic fluid, glucose is known as common currency of metabolism and the developing embryo is more dependent on this. The purpose of this study is to provide basic data on the capacity of amniotic fluid as a source of glucose for neurulating rat embryos. In the first part of this paper, isolated days 10, 11 and 16 rat embryos with intact amnion were used to pursue the change of the glucose concentratons in the amniotic fluid. The day 10 embryo amniotic fluid glucose disappeared after 20 minutes, and the day 11 amniotic fluid glucose disappeared after 33 minutes. The day 16 amniotic fluid glucose showed no significant changes during 40 minutes. In the second part of this paper, the author determined the time required for glucose concentraton in the day 10 amniotic fluid to be 0 mg% at glucose free Hanks` solution. The day 10 amniotic fluid glucose disappeared afttar 10 minutes. Another embryos were exposed to glucose free Hank`s solution for 10 minutes, and switched immediately to regular Hank`s for measuring the changes of amniotic fluid glucose, that is `charging Phenomena`. During the first 15 minutes amniotic glucose was charged to nearly normal level, and after that it decreased. These changes were similar to the results from the first experiment. These results indicate that neurulating embryo has a potential for restoring its amniotic glucose concentration to the normal level rapidly. So harmful effects of hypoglycemic states may be compensated by this `charging phenomena` of amniotic fluid during neurulation.
Amnion ; Amniotic Fluid* ; Animals ; Blood Circulation ; Embryonic Structures* ; Female ; Glucose* ; Metabolism ; Nervous System ; Neural Plate ; Neural Tube ; Neurulation ; Rats*

Human embryology is the study of development from a single cell to a baby in 9 months. Implantation occurs at the end of the first week of development. The second week of development is known as the week of 2's. Gastrulation, the most characteristic event occurring in the third week, establishes three germ layers composed of ectoderm, mesoderm, and endoderm. The three germ layers and neural crest cells lead to the development of their own tissues and organs during the embryonic period, which extends from the third to the eighth week. Major congenital malformations occur in the embryonic period. The fetal period, from the third month to the day of birth, is the time for maturation of tissues and organs, and growth of the body. Because of the close relationship between embryology and congenital abnormalities, knowledge of human development is essential to assess the effects on the embryo when the mother has been exposed to teratogens. This paper briefly reviews the normal embryonic development and associated congenital malformation.
Congenital Abnormalities ; Ectoderm ; Embryology ; Embryonic Development* ; Embryonic Structures* ; Endoderm ; Female ; Gastrulation ; Germ Layers ; Human Development ; Humans* ; Mesoderm ; Mothers ; Neural Crest ; Neurulation ; Parturition ; Pregnancy ; Teratogens

Chick embryos have been used widely as model systems for studies in experimental embryology and teratology. Especially early chick embryos are very useful for studies of neural tube defects. Local anesthetics such as lidocaine, tetracaine and ketamine are known to inhibit the formation of microfilaments and cause neural tube defects. We made a try to figure out the effect of local anesthetics on neurulation in early chick embryo, which is stage 8 by Hamburger & Hamiliton classification. After 6~9 hours incubation in media treated with above local anesthetics, we observed the effects of these agents by LM and EM. Stage 8 chick embryos responded to local anesthetics in a dose related manner. Tetracaine showed most potent effects. Neural folds failed to make a contact, so the neural tube was left open. In high dosage, the case of no growth or little growth of embryo was also observed. On scanning electron microscopic examination, the surface of neuroepithelium was flattened in embryos treated with ketamines. On transmission electron microscopic examination. neuroepithelium of embryos cultured in ketamine showed the decrease of microfilaments and less conspicuous feature of mitochondria and rough ER(endoplasmic reticulum)'s.
Actin Cytoskeleton ; Anesthetics, Local* ; Animals ; Chick Embryo* ; Classification ; Embryology ; Embryonic Structures ; Ketamine ; Lidocaine ; Microscopy, Electron ; Mitochondria ; Neural Crest ; Neural Tube ; Neural Tube Defects ; Neurulation* ; Teratology ; Tetracaine

Chick embryos have been used widely as model systems for studies in experimental embryology and teratology. Especially early chick embryos are very useful for studies of neural tube defects. We made a try to figure out the effect of Ca++ on neurulation using Ca++ antagonist and Ca++ free media in early chick embryo, which is stage 8 by Hamburger & Hamilton classification. After 6~9 hours incubation in media treated with verapamil and media without Ca++, we observed the effects of these agents by LM and EM. All of 12 embryos incubated in Ca++ free media showed that neural tube was diffusely opened along the whole axis and other deformity was not found. The chick embryos cultured in medium treated with verapamil revealed various abnormalities in dose related manner. The case of arrest of the growth was also observed, which was not found Ca++ free media group. On scanning electron microscopic examination, the surface of neuroepithelium was flattened in embryos cultured in Ca++ free media.
Animals ; Axis, Cervical Vertebra ; Chick Embryo* ; Classification ; Congenital Abnormalities ; Embryology ; Embryonic Structures ; Microscopy, Electron, Scanning ; Neural Tube ; Neural Tube Defects ; Neurulation* ; Teratology ; Verapamil

Teratogenic effects of a diphenylhydantoin on the neurulation of the explanted early chick embryos were studied using the punched-out filter paper explantation technique. The 6th to 9th Hamburger and Hamilton staged chick embryos were explanted and cultured in the Ham's F-10 media treated with 15 microgram/ml, 30 microgram/ml, 60 microgram/ml, 90 microgram/ml, 120 microgram/ml of diphenylhydantoin in the CO2 incubator for 6-9 hours. The morphological chracteristics and the ultrastructural changes of the neuroepithelium of early chick embryos were compared with the control and experimental group using the stereomicroscope and the electron microscope. Of th 40 chick embryos cultured in the Ham's F-10 media without drug, 37 embryos(92.5%) developed normally and 3 embryos(7.5%) developed abnormally in 94 embryos(61.4%). The frequent anomalous features of the embryos were deformities of the neural folds in the cranial regions, failure of neural tube closure, dispersion of somites and developmental arrest. The scanning electron microscopic findings of neuropithelial cells of abnormally developed embryos were diminished surface blebs and microvilli, flattened and smooth cellular surfaces, and irregular size of cells. The transmission electron microscopic findings of neuroepithelial cells of abnormally developed embryos showed no significant changes of the development of intracellular organelles except the smooth cellular surface and mild underdevelopment of microfilaments.
Actin Cytoskeleton ; Animals ; Blister ; Chick Embryo* ; Congenital Abnormalities ; Embryonic Structures ; Incubators ; Microvilli ; Neural Crest ; Neural Tube ; Neuroepithelial Cells ; Neurulation* ; Organelles ; Phenytoin* ; Somites

Teratogenic effects of carbamazepine, an anticonvulsant, on the neurulation of the explanted early chick embryos were studied utilizing the punched-out filter paper explantation and culture technique. Fresh fertilized white leghorn hen eggs were incubated for 20-30 hours in an egg incubator. The Hamburger and Hamilton stage 4-11 chick embryos were explanted using the punched-out filter paper explantation technique and cultured in the CO2 cell culture incubator for 6-10 hours. They were randomly divided into a control group and an experimental group. The experimental group was divided into five subgroups according to the carbamazepine concentrations of 20micrometer 40micrometer 100micrometer 200micrometer 400micrometer with which the Ham's F-10 culture media were treated. The morphological characteristics and the incidences of teratogenic effects on the neurulation of early chick embryos in the control and experimental groups were compared with each other using the stereomicroscope and the electron microscope. The chick embryos of the same developmental stage were selected from the control and experimental groups, and immunohistochemical staining for fibronectin was done by the double-bridge PAP method. The results were as follows. 1) Of the 41 chick embryos cultured in the Ham's F-10 media without carbamazepine, 38 embryos(92.7%) developed normally, and 3 embryos(7.3%) developed abnormally. In contrast, among the 98 embryos cultured in the carbamazepine-treated media, 54 embryos(55.1%) developed abnormally. The frequent anomalous features were deformities of the neural folds, failure of neural tube closure, derangement of somites, and developmental arrest. 2) The frequency and severity of abnormal embryos increased in dose-dependent fashion. The embryos cultured in the media treated each with 20micrometer 40micrometer 100micrometer 200micrometer 400micrometer of carbamazepine developed abnormally in 12.5%, 21.1%, 60.0%, 81.0%, 86.4% respectively. 3) The scanning electron microscopic findings in neuroepithelial cells of abnormally developed embryos were flattened and smooth cellular surface with diminished surface blebs and microvilli, and size irregularity of the cells. On transmission electron microscope, underdevelopment of intracellular microfilaments was seen, but there was no significant change in the intracellular organelle. 4) The immunohistochemical stainability of the extracellular fibronectin at the basal side of the neuroepithelium was decreased in the carbamazepine-treated embryos.
Actin Cytoskeleton ; Animals ; Blister ; Carbamazepine ; Cell Culture Techniques ; Chick Embryo* ; Congenital Abnormalities ; Culture Media ; Culture Techniques ; Eggs ; Embryonic Structures ; Fibronectins* ; Incidence ; Incubators ; Microvilli ; Neural Crest ; Neural Tube ; Neuroepithelial Cells ; Neurulation* ; Organelles ; Ovum ; Somites