• Applied Microscopy
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• 제21권2호
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• pp.1-13
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• 1991

In order to investigate the factors of the control mechanism of somitogenesis, early chick embryos (H-H stage $8{\sim}13$) were treated with heat shock, ${\alpha}$-amanitin and cycloheximide and morphological changes of somite were examined by light microscopy, transmission and scanning electron microscopy. In normal chick embryo, somites were formed from the somitomere which preexisted in segmental plate. Somites were wrapped with extracellular collagen fibrils and connected with neural tube, notochord and ectoderm. And then, somites were differentiated to sclerotome, dermatome and myotome by the interaction of nervous tissue. Abnormal somites were observed after formation of six or seven so mites in heat shock treated group. Amounts of collagen fibrils were obviously decreased in this group. In cycloheximide treated group, most so mites were smaller and neural tube formation was incomplete. Chromatins were condenced and formed several heterochromatins in the nucleus of somite cells. Lipid like cytoplasmic dense mass and lipid droplets were also observed. Segmentation of somites seemed to be normal progress in ${\alpha}$-amanitin treated group. Center of somite, however, hollowed in longitudinal sectioned samples. These results suggested that so mites were already existed in the segmental plate as the form of somitomere. Segmented somites were contacted with neural tube or notochord and the somites were tightly connected with each other by the extracellular collagen fibrils which were secreted from neuroepithelium and somite cells. Somites are thought to differentiate into sclerotome, dermatome and myotome by these interactions.

• Fisheries and Aquatic Sciences
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• 제21권12호
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• pp.37.1-37.10
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• 2018

The larvae and juveniles of Porocottus leptosomus belonging to the family Cottidae were collected (n = 95, 3.9-16.5 mm in body length, BL) from Busan, Korea, in March 2015. The larvae and juvenile were identified using DNA barcoding as P. leptosomus, and their morphological description was presented in detail. The yolk-sac larvae (3.9-5.6 mm BL) body was slightly compressed, the head was large, the eye was round and large, and the anus was before the middle of the body. The preflexion larvae (5.2-10.0 mm BL) body length drastically increased; caudal fin rays began to occur. The flexion larvae (9.4-11.8 mm BL) notochord flexion started; dorsal, pectoral, and anal fin rays began to occur; pelvic fin buds are seen; they possessed a pair of parietal spine; and a pair of supraocular cirri was first to develop. At 12 mm BL, the notochord was completely flexed. The larva stage (3.9-12.6 mm SL) had the stellate melanophores in the head, isthmus, gut, and tail (along to the ventral midline). During the juvenile stage (11.4-16.5 mm BL), melanophores covered the head and began to form five black bands on the side of the body. The larvae of P. leptosomus spent pelagic life, but moved to the bottom during the juvenile stage. The larvae and juveniles of P. leptosomus differ from other cottid larval fishes by body shape, melanophore head pattern, and spine development. P. leptosomus can be distinguished from Porocottus allisi by morphological development and the occurrence of larval fish: preopercular spine development, melanophore pattern, and caudal fin development.

• 한국수산과학회지
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• 제42권6호
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• pp.725-728
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• 2009

Four specimens of Cynoglossus larvae (3.2-7.3 mm in notochord length, NL) collected from the middle Yellow Sea in August, 2008 were identified as Cynoglossus joyneri larvae based on morphological characteristics; (1) the two elongated dorsal fin rays on the parietal region, (2) protruded abdomen, (3) no melanophores on the mediolateral trunk and tail. Larva of 3.2 mm NL is compressed with a little big head and tapering, long tail. Larva of 7.0 mm NL has 115 dorsal fin and 85 anal fin rays, which are the same to those of adult. Larva of 7.3 mm NL tended to have concave part in the fringe of forehead, in which left-side eye may move to the other side.

• Journal of Korean Neurosurgical Society
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• 제29권9호
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• pp.1258-1261
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• 2000

Intraspinal neurenteric cyst is rare congenital lesion derived from disorder of notochord formation. Most of these are located ventral to the spinal cord and conventional posterior approach is considered to be effective method as initial treatment modality. This cyst can recur, but the risk of reccurence after partial removal through long term follow-up has not been determined. We experienced one case of cervical neurenteric cyst which recurred after partial removal through laminectomy. The magnetic resonance imaging and postmyelography computerized tomography revealed an intradural extramedullary cystic lesion anterior to the cervical cord at the fifth cervical vertebra level. We performed anterior cervical corpectomy and cyst was totally removed. The patient's neurological symptom was improved postoperatively. Neurenteric cyst located ventrally to the cervical spinal cord should be removed through anterior route for direct visualization of the relationship between the cyst wall and the spinal cord.

• Radiation Oncology Journal
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• 제17권1호
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• pp.52-56
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• 1999

척삭종은 notochordal remants에서 발생하는 비교적 드문 질환으로 천미골에서 약 50$\%$정도 발생한다. 이들은 주위 조직으로 깊숙히 침윤하여 마비증세를 일으키며 수술에 의한 완전절제가 어려워 국소재발을 겪게 된다. 천미골에서 발생하는 척삭종은 이와 같은 국소재발 외에 원격전이가 잘 발생하는 것으로 알려져 있으며 본 저자 역시 유사한 2예를 경험하였기에 이에 대한 문헌고찰과 함께 보고하고자 한다.

• 한국양식학회지
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• 제12권2호
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• pp.115-122
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• 1999

Exposure experiments during the egg development were conducted to assess the influences of 5 different concentrations (0, 25, 50, 75 and 100%) of water-soluble fraction (WSF) of Kuwait crude oil on the eggs and larvae of black seabream (Acanthopagrus schlegeli), red seabream (Pagrus major) and olive flounder (Paralichthys olivaceus). All experiments were triplicated. Hatching time and hatching rate were examined on the eggs. The median lethal time ($LT_{50}$), morphological abnormality and swimming activity (swimming frequency and speed) of larvae were also investigated. The time and rate of egg hatching were not significantly influenced by WSF on the eggs of the fishes. The larvae exposed to WSF during the egg development were also not significantly influenced on the $LT_{50}$ and swimming activity. But the higher morphological abnormalities of notochord were observed from the larvae in 100% WSF exposure.

• Journal of Chest Surgery
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• 제54권2호
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• pp.158-161
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• 2021

Chordoma is a rare malignant bone tumor originating from the embryonic notochord. Herein, we present a case of thoracic chordoma located at T3-T5 that was misdiagnosed as primary mediastinal adenocarcinoma. The patient underwent neoadjuvant chemoradiation and the disease showed little response. Due to vertebral body invasion, we performed en bloc mass removal and partial corpectomy (T4-5) in collaboration with orthopedic surgeons.

• 한국어류학회지
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• 제12권4호
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• pp.230-235
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• 2000

1998년(年) 5월(月)부터 7월(月)까지 전라남도 순천만에서 난치자 net를 사용하여 채집한 시료를 실험실에서 분류 및 동정하여 준치 자치어(仔稚魚)에 대한 형태발달 및 내부골격발달을 관찰한 결과는 다음과 같다. 평균전장이 5.02 mm (n = 50)인 자어(仔魚)는 입과 항문이 열려 있었고, 항문은 체장의 약 73% 지점에 위치하였으며, 근절수는 36~38+15~16 = 51~54개였다. 가장 먼저 견대부에서 쇄골이 골화하였다. 평균전장이 7.82 mm (n = 50)로 자어(仔魚)는 모든 지느러미가 분화하여 분리되었고, 항문은 전장의 약 75%에 위치하였으며, 이 시기에 척색말단이 굽어지기 시작하였다. 두개골에 부설골이 골화하였고, 내장골에서 섭이와 관련하여 아래턱에서 치골이 골화되었다. 평균전장이 9.84 mm(n=50)인 자어(仔魚)는 척색말단이 완전히$45^{\circ}C$로 굽어져 있었고, 항문의 위치가 전장의 약 67% 지점에 위치하여 점차적으로 항문이 체측의 앞쪽으로 위치하기 시작하였다. 평균전장이 23.32 mm (n = 50)의 개체는 체고가 전장의 18~20%로 증가하여 성어와 닮아 있었고, 모든지느러미 줄기수가 정수에 달하여 치어기(稚魚期)로 이행되어 있었다. 평균전장 26.52 mm인 치어(稚魚)에서 모든 골격이 완성되었다.

• 한국어류학회지
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• 제13권1호
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• pp.69-73
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• 2001

1991년 5월에 포항시 청하면 방어리 소재의 포항수산 종묘시험장 앞 해안에서 채집한 학공치, Hyporhampus sajori (Temminck et Schlegel) 수정란을 부화 사육하여 자치어의 형태발달을 관찰한 결과는 다음과 같다. 부화 직후의 자어는 전장이 7.00~8.50 mm(평균 7.80 mm, n=5)로 입과 항문이 열려 있었고, 근절은 40~42+17~18=57~60개였다. 흑색소포는 머리꼭대기에서 꼬리자루에 이르기까지 등쪽 정중선을 따라 줄지어 있었고, 또한 소화관 등쪽과 항문의 뒤쪽부터 꼬리자루까지 분포하였으며, 두부와 아래턱, 위턱, 그리고 난황 부위와 척색을 따라 흑색소포가 드문드문 분포하였다. 부화 후 3일의 자어는 전장이 8.60~10.90 mm (평균 9.83 mm, n=5)인 자어는 난황을 완전히 흡수하고, 척색 말단이 45^{\circ}로 굽어 후기자어기에 달하였다. 부화 후 37일의 후기자어는 전장이 32.37~44.95mm (평균 35.26 mm, n=5)로 등지느러미 줄기수 15~17개, 뒷지느러미 줄기수 16~17개, 가슴지느러미 줄기수 12~13개, 배지느러미 줄기수 6개, 꼬리지느러미 줄기수 11~12+12=23~24개로 각 지느러미 줄기 수가 정수에 달하여 치어기로 이행하였다.

• 한국수산과학회지
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• 제29권4호
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• pp.497-502
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• 1996

1990년 3월, 경상북도 영덕군 강구면에 위치한 오십천과 경상남도 밀양시 밀양강에서 채집하여 인공수정한 난을 실험실로 운반하여 난발생과정과 부화자어의 성장에 따른 형태변화를 관찰한 결과는 다음과 같다. 1. 빙어의 수정난은 구형의 침성부착난으로 무색 투명하며, 난경은 $0.85\~1.05mm$ (평균 0.97mm, n=50)이다. 2. 부화에 소요된 시간은 평균 $16.5^{\circ}C$에서 약 170시간만에 부화한다. 3. 부화직후의 자어는 전장 $3.85\~4.25mm$ (평균 4.05 mm, n=10)로, 아직 입과 항문이 열려 있지 않고, 눈에 색소포가 착색되어 있으며, 근절수는 $52\~54$개이다. 4. 부화 $4\~5$일째의 자어는 전장이 $5.20\~5.65mm$ (평균 5.37mm, n=10)로 난황은 거의 흡수되고, 눈의 색소는 더욱 짙어진다. 5. 부화 20일째의 후기자어는 전장이 $8.20\~8.55\;mm$(평균 8.38mm, n=10)로 척색말단이 $45^{\circ}$ 각도로 위로 굽어진다. 6. 부화 25일째의 후기자어는 전장이 $9.15\~9.75mm$ (평균 9.63mm, n=10)로 등지느러미와 뒷지느러미에 각각 융기하기 시작하여 원기가 나타난다.