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 第17回日本臨床検査学教育学会学術大会 (2023.8.23-24, 天理）で発表しました。 八田桃佳、金橋徹、今井宏彦、山田重人、高桑 徹也、拡散テンソル画像を用いた水晶体線維細胞の配向性の検討 ＊八田さんが 優秀発表賞（大学院）を受賞しました。おめでとうございます!! 中井尚一、松林潤、金橋徹、今井宏彦、山田重人、大谷浩、高桑徹也、ヒト胎児期初期から中期の血管径変化より紐解く循環動態の検討 金橋 徹、伊吹謙太郎、山田 稔、榛葉旭恒、高桑徹也、寄生虫顕微鏡スライド標本のデジタル化に向けた取り組み  比較解剖学的研究で哺乳類の気管支樹の基本モデルとして提案されている左右の気管支の対称性が、ヒトの胎児の気管支樹に当てはまるかどうかを検討しました。 ヒト成人の気管支分岐構造の原型が胎児期に形成され、維持されることを実証しました。 すべての肺葉気管支、B6、B8、B9、および B10 の亜分節気管支の形態および分岐位置は、遺伝的に決定される可能性があります。 一方、B10 の亜分節気管支以降の末梢枝では個々の胚間に共通の構造は見つからず、この領域での枝形成は遺伝的要因よりも環境的要因により影響されることが示唆されました。 Fujii S, Muranaka T, Matsubayashi J, Yamada S, Yoneyama A, Takakuwa T. Bronchial tree of the human embryo: Examination based on a mammalian model. J Anatomy 2023, in press http://doi.org/10.1111/joa.13946 . The symmetry of right and left bronchi, proposed in a previous comparative anatomical study as the basic model of the mammalian bronchial tree, was examined to determine if it applied to the embryonic human bronchial tree. Imaging data of 41 human embryo specimens at Carnegie stage (CS) 16–23 (equivalent to 6–8 weeks after fertilization) belonging to the Kyoto collection were obtained using phase-contrast X-ray computed tomography. Three-dimensional bronchial trees were then reconstructed from these images. Bronchi branching from both main bronchi were labeled as dorsal, ventral, medial, or lateral systems based on the branching position with numbering starting cranially. The length from the tracheal bifurcation to the branching point of the labeled bronchus was measured, and the right-to-left ratio of the same labeled bronchus in both lungs was calculated. In both lungs, the human embryonic bronchial tree showed symmetry with an alternating pattern of dorsal and lateral systems up to segmental bronchus B9 as the basic shape, with a more peripheral variation. This pattern is similar to that described in adult human lungs. Bronchial length increased with the CS in all labeled bronchi, whereas the right-to-left ratio was constant at approximately 1.0. The data demonstrated that the prototype of the human adult bronchial branching structure is formed and maintained in the embryonic stage. The morphology and branching position of all lobar bronchi and B6, B8, B9, and the subsegmental bronchus of B10 may be genetically determined. On the other hand, no common structures between individual embryos were found in the peripheral branches after the subsegmental bronchus of B10, suggesting that branch formation in this region is influenced more by environmental factors than genetic factors.  第63回日本先天異常学会で発表しました (2023.7.28-30、つくば） 石田七彩、植田優生、松林潤、金橋徹、今井宏彦、山田重人、高桑徹也、生理的臍帯ヘルニア期のヒト中腸ループと腸間膜の経時的構造変化 岩佐結生、金橋徹、松林潤、今井宏彦、大谷 浩、高桑徹也、腹直筋の腱画形成過程  福井さんの修士論文がJ Anatomyに受諾されました。ヒト胎児期初期の左房の形成を肺静脈のとりこみと左心耳の形成を中心に解析しました。 Fukui N, Toru KanahashiT, MatsubayashiJ, ImaiH, YoneyamaA, OtaniH, YamadaS, Takakuwa T. Morphogenesis of the pulmonary vein and left atrial appendage in human embryos and early fetuses. J Anatomy 2023, in press, https://doi.org/10.1111/joa.13941 Abstract The left atrium wall has several origins, including the body, appendage, septum, atrial–ventricular canal, posterior wall, and venous component. Here, we describe the morphogenesis of left atrium based on high-resolution imaging (phase-contrast X-ray computed tomography and magnetic resonance imaging). Twenty-three human embryos and 19 fetuses were selected for this study. Three-dimensional cardiac images were reconstructed, and the pulmonary veins and left atrium, including the left atrial appendage, were evaluated morphologically and quantitatively. The positions of the pericardial reflections were used as landmarks for the border of the pericardial cavity. The common pulmonary vein was observed in three specimens at Carnegie stage 17–18. The pericardium was detected at the four pulmonary veins (left superior, left inferior, right superior, and right inferior pulmonary veins) at one specimen at Carnegie stage 18 and all larger specimens, except the four samples. Our results suggest that the position of the pericardial reflections was determined at two pulmonary veins (right and left pulmonary vein) and four pulmonary veins almost simultaneously when the dorsal mesocardial connection between the embryo and heart regressed. The magnetic resonance images and reconstructed heart cavity images confirmed that the left atrium folds were present at the junction between the body and venous component. Three-dimensional reconstruction showed that the four pulmonary veins entered the dorsal left atrium tangentially from the lateral to the medial direction. More specifically, the right pulmonary veins entered at a greater angle than the left pulmonary veins. The distance between the superior and inferior pulmonary veins was shorter than that between the left and right pulmonary veins. Three-dimensional reconstruction showed that the venous component increased proportionally with growth. No noticeable differences to discriminate between the right and left parts of the venous component emerged, while the junction between the venous component and body gradually became inconspicuous but was still recognizable by the end of the observed early fetal period. The left superior pulmonary vein had the smallest cross-sectional area and most flattened shape, whereas the other three were similar in area and shape. The left atrial appendage had a large volume in the center and extended to the periphery as a lobe-like structure. The left atrial appendage orifice increased in the area and tended to become flatter with growth. The whole left atrium volume^(1/3) increased almost proportionally with growth, parallel to the whole heart volume. This study provided a three-dimensional and quantitative description of the developmental process of left atrium, comprising the venous component and left atrial appendage formation, from the late embryonic to the early fetal stages.  胚子期の股関節の肢位についての論文がPLoS Oneに掲載されました。熊野くんが卒業研究で行ったデータに、胚子期の標本のデータを追加し解析しました。大腿骨（股関節）の肢位を正確に測定し、下肢の発達の時間軸を確立することを目的とした論文です。
60. Takakuwa T, Saizonou MA, Fujii S, Kumano Y, Ishikawa A, Aoyama T, Imai H, Yamada S, Kanahashi T. Femoral posture during embryonic and early fetal development: An analysis using landmarks on the cartilaginous skeletons of ex vivo human specimens. PLOS one, 2023, 18(5): e0285190. https://doi.org/10.1371/journal.pone.0285190.  AbstractThe pre-axial border medially moves between the fetal and early postnatal periods, and the foot sole can be placed on the ground. Nonetheless, the precise timeline when this posture is achieved remains poorly understood. The hip joint is the most freely movable joint in the lower limbs and largely determines the lower-limb posture. The present study aimed to establish a timeline of lower-limb development using a precise measurement of femoral posture. Magnetic resonance images of 157 human embryonic samples (Carnegie stages [CS] 19–23) and 18 fetal samples (crown rump length: 37.2–225 mm) from the Kyoto Collection were obtained. Three-dimensional coordinates of eight selected landmarks in the lower limbs and pelvis were used to calculate the femoral posture. Hip flexion was approximately 14° at CS19 and gradually increased to approximately 65° at CS23; the flexion angle ranged from 90° to 120° during the fetal period. Hip joint abduction was approximately 78° at CS19 and gradually decreased to approximately 27° at CS23; the average angle was approximately 13° during the fetal period. Lateral rotation was greater than 90° at CS19 and CS21 and decreased to approximately 65° at CS23; the average angle was approximately 43° during the fetal period. During the embryonic period, three posture parameters (namely, flexion, abduction, and lateral rotation of the hip) were linearly correlated with each other, suggesting that the femoral posture at each stage was three-dimensionally constant and exhibited gradual and smooth change according to growth. During the fetal period, these parameters varied among individuals, with no obvious trend. Our study has merits in that lengths and angles were measured on anatomical landmarks of the skeletal system. Our obtained data may contribute to understanding development from anatomical aspects and provide valuable insights for clinical application.  第128回解剖学会で発表します (2023.3.18-20, 仙台, 現地開催)。 金橋先生の演題が、2022年度 第16回肉眼解剖トラベルアワード（献体協会賞）受賞しました!! 石田さんの演題が、学部学生優秀発表賞を受賞しました。!! 昨年度の岩佐さんに続いて2年連続の受賞です。 
 松成さんの卒業研究がAnat Recに掲載されました。 硬膜のような袋状の構造物は、組織形態学的手法では立体的な形状がとらえにくかったのですが、MRI等の立体情報の活用により可能になりました。
59. Matsunari C, Kanahashi T, Otani H, Imai H, Yamada S, Okada T, Takakuwa T. Tentorium cerebelli formation during human embryonic and early fetal development. Anat Rec (Hoboken) 2023, 306(3), 515-526 AbstractThe morphologies of the fetal tentorium cerebelli (TC) and brain influence each other during development. This study aimed to analyze and more comprehensively understand the three-dimensional morphogenesis of the TC and fetal brain. We examined magnetic resonance imaging from 64 embryonic and fetal specimens (crown-rump length range, 9.2–225 mm). During the embryonic period, the lateral folds of the TC elongated to traverse the middle part of the midbrain. The TC and falx cerebri appeared separated, and no invaginations at the parieto-occipital region were observed. In the early fetal period, the cerebrum covered approximately half of the midbrain. The separation of the dural limiting layer at the parieto-occipital region widened from the posterior cerebrum to the cranial cerebellum. The lateral folds of the TC were spread between its tip, continuous with the falx cerebri, and its base plane, located between the midbrain and rostral hindbrain. Differences in the TC components’ growth directions gradually diminished as the cerebrum covered the midbrain. We observed rotation of the TC at its median section according to its growth, which ceased in the middle fetal period. The brainstem and cerebellum extended inferiorly via differential growth, with the cerebrum covering them superiorly. The morphology of the TC curved to conform to the cerebellar and cerebral surfaces. Our present study suggests that factors affecting TC morphology differ between the early and middle fetal periods. Present data provided a more comprehensive view of TC formation according to developmental stage.  2022年度修士論文発表会が行われました (2/2-3, 第８講義室） 今年は、感染対策に留意しながら対面で行われました。聴衆を増え、日常を取り戻しつつあります。 Three-dimensional analysis of the umbilical vein and the ductus venosus at the human embryonic and early fetal stagesヒト胚子期・胎児期初期における臍帯静脈と静脈管の3次元的解析 磯谷 菜穂子 Morphogenesis of the pulmonary vein and the left atrial appendage in human embryos and early fetusesヒト胚子・胎児期初期における肺静脈・左心耳の形態形成 福井 成美   |
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