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金橋先生の論文がJ Anatに受諾

CRL71 mm胎児右側面像

金橋先生の横隔膜形成についての論文がJ. Anat.に受諾されました。

この研究は、胚子期後期から胎児期初期のヒト横隔膜の形態形成および線維構造の質的評価をすることを目的とし、従来使用しているT1強調像に加えて、DTIを用いた高解像度MRI画像を導入して解析しました。

  • 横隔膜はCS20で完全に閉鎖した
  • CRLが46mm以上のサンプルでは、​​胸骨、肋骨、腰部、および食道裂孔を囲む領域が肥厚したが、横隔膜の中心や左右の横隔膜ドーム頂部の厚さは変化しない。
  • 肋骨と腰部のすべての線維は、大静脈開口部と食道裂孔周囲を除いて、左右の半横隔膜ドームに向かって走行した

Kanahashi T, Imai H, Otani H, Yamada S, Yoneyama A, Takakuwa T. Three-dimensional morphogenesis of the human diaphragm during the late embryonic and early fetal period: Analysis using T1-weighted and diffusion tensor imaging. J Anat. 2022, in press, DOI: 10.1111/joa.13760

Abstract

A precise understanding of human diaphragm development is essential in fetal medicine. To our knowledge, no previous study has attempted a three-dimensional (3-D) analysis and evaluation of diaphragmatic morphogenesis and development from the embryonic to the early fetal period. This study aimed to evaluate the morphogenesis and fibrous architecture of the developing human diaphragm during the late embryonic and early fetal periods. Fifty-seven human embryos and fetuses (crown-rump length [CRL] = 8–88 mm) preserved at the Congenital Anomaly Research Center of Kyoto University and Shimane University were analyzed. 3-D morphogenesis and fiber orientation of the diaphragm were assessed using phase-contrast X-ray computed tomography, T1-weighted magnetic resonance imaging (T1W MRI), and diffusion tensor imaging (DTI). T1W MR images and DTI scans were obtained using a 7-T MR system. The diaphragm was completely closed at Carnegie stage (CS) 20 and gradually developed a dome-like shape. The diaphragm was already in contact with the heart and liver ventrally in the earliest CS16 specimen observed, and the adrenal glands dorsally at CS19 or later. In the fetal period, the diaphragm contacted the gastric fundus in samples with a CRL ≥41 mm, and the spleen in samples with a CRL ≥70 mm. The relative position of the diaphragm with reference to the vertebrae changed rapidly from CS16 to CS19. The most cranial point of the diaphragm was located between the 4th and 8th thoracic vertebrae, regardless of fetal growth, in samples with a CRL ≥16 mm. Diaphragmatic thickness was nearly uniform (0.15–0.2 mm) across samples with a CRL of 8 mm to 41 mm. The sternal, costal, lumbar parts, and the area surrounding the esophageal hiatus thickened with growth in samples with a CRL ≥46 mm. The thickness at the center of the diaphragm and the left and right hemidiaphragmatic domes did not increase with growth. Tractography showed that the fiber orientation of the sternal, costal, and lumbar parts became more distinct as growth progressed in CS19 or later. All fibers in the costal and lumbar regions ran toward the left and right hemidiaphragmatic domes, except for those running to the caval opening and esophageal hiatus. The fiber orientation patterns from the right and left crura surrounding the esophageal hiatus were classified into three types. Distinct fiber directions between the costal and sternal, and between the costal and lumbar diaphragmatic parts were observable in samples with a CRL ≥46 mm. Anterior costal and sternal fibers ran toward the center. Fiber tracts around the center and the left and right hemidiaphragmatic domes; between the costal and lumbar orientations; and between the costal and sternal orientations showed a tendency for decreasing fractional anisotropy values with fetal growth, and showed less density than other areas. In conclusion, we used 3-D thickness assessment and DTI tractography to identify qualitative changes in the muscular and tendonous regions of the diaphragm during the embryonic and early fetal periods. This study provides information on normal human diaphragm development for the progression of fetal medicine and furthering the understanding of congenital anomalies.

’22 オープンキャンパス

22オープンキャンパスが行われました(外部リンク)。今年も、残念ながら大部分がOn lineでした。

IFAA2022で発表しました

The 20th Congress of International Federation of Associations of Anatomists (IFAA2022) 2022,8/5-7, Istanbul,Turkey/Onlineで発表しました。

Ishikawa A, Nagai-Tanima M, Ishida K, Imai H, Aoyama T, Takakuwa T. Three-dimensional analysis of knee joint development during the human fetal period.

野原さんの修士論文がJ Anatに受諾されました

野原さんの修論がJ Anatomyに受諾されました。

胚子期末の2次口蓋形成時の舌、口蓋だな、下顎(メッケル軟骨)、鼻腔の動きを主成分分析等を用いて解析し、口蓋だな上昇、融合前の数日間の下顎(メッケル軟骨)、舌が極度に前後に圧縮される時期を”approach period”として見出しました。

  • 口蓋棚の上昇・癒合はCS23中におきる。
  • 「アプローチ期間」の間、下顎骨 (メッケル軟骨と舌) と上顎骨 (口蓋と鼻腔) の構造は位置を変えなかったが、構造の両方のグループが前後に圧縮されていた。
  • 口蓋棚上昇前後では、上顎と下顎の構造、特に舌の上の棚の配置、および舌と下顎骨の突出の間に有意な変化を示した。
  • これらの結果は、メッケル軟骨の成長が舌を再配置して棚の上昇を促進する上で積極的な役割を果たしていることを示唆している。

ヒトの二次口蓋閉鎖の 3 つの異なるPhaseを表す現在のデータは、口蓋棚の水平配置の前後に発生する形態学的成長変化と、ヒトの二次口蓋をうまく閉じるためのそれらの融合の理解を進めることができます。

 Nohara A, Owaki N, Matsubayashi J, Katsube M, Imai H, Yoneyama A, Yamada S, Kanahashi T, Takakuwa T. Morphometric analysis of secondary palate development in human embryos. J Anatomy, 2022, in press, DOI:10.1111/joa.13745

Abstract

Rapid shelf elevation and contact of the secondary palate and fusion reportedly occur due to a growth-related equilibrium change in the structures within the oro-nasal cavity. This study aimed to quantitatively evaluate complex three-dimensional morphological changes and their effects on rapid movements, such as shelf elevation and contact, and fusion. Morphological changes during secondary palate formation were analyzed using high-resolution digitalized imaging data (phase-contrast X-ray computed tomography and magnetic resonance images) obtained from 22 human embryonic and fetal samples. The three-dimensional images of the oro-nasal structures, including the maxilla, palate, pterygoid hamulus, tongue, Meckel’s cartilage, nasal cavity, pharyngeal cavity, and nasal septum, were reconstructed manually.

palatal shelves were not elevated in all the samples at Carnegie stage (CS)21 and CS22 and in three samples at CS23. In contrast, the palatal shelves were elevated but not in contact in one sample at CS23. Further, the palatal shelves were elevated and fused in the remaining four samples at CS23 and all three samples from the early fetal period. For each sample, 70 landmarks were subjected to Procrustes and principal component (PC) analysis. PC-1 accounted for 67.4% of the extracted gross changes before and after shelf elevations. Notably, the PC-1 values of the negative and positive value groups differed significantly. The PC-2 value changed during the phases in which the change in the PC-1 value was unnaturally slow and stopped at CS22 and the first half of CS23. This period, defined as the “approach period”, corresponds to the time before dynamic changes occur as the palatal shelves elevate, the tongue and mandibular tip change their position and shape, and secondary palatal shelves contact and fuse. During the “approach period”, measurements of PC-2 changes showed that structures on the mandible (Meckel’s cartilage and tongue) and maxilla (palate and nasal cavity) did not change positions, albeit both groups of structures appeared to be compressed anterior-posteriorly. However, during and after shelf elevation, measurements of PC-1 changes showed significant changes between maxillary and mandibular structures, particularly positioning of the shelves above the tongue and protrusion of the tongue and mandible. These results suggest an active role for Meckel’s cartilage growth in repositioning the tongue to facilitate shelf elevation. The present data representing three distinct phases of secondary palate closure in humans can advance the understanding of morphological growth changes occurring before and after the horizontal positioning of palatal shelves and their fusion to close the secondary palate in humans successfully.