Ossification of Transverse Ligament of Atlas Causing Cervical Myelopathy: A Case Report and Review of the Literature

A case of ossification of transverse ligament of atlas (TLA) is reported. A 76-year-old female suffered from a transverse type myelopathy was successfully treated by posterior decompression. Dynamic lateral plain radiographs showed irreducible atlantoaxial subluxation (AAS). A computed tomogram revealed ossified mass compatible to ossification of TLA. Coalition of the atlantooccipital joints and osteoarthritis of the atlantoaxial joints with degenerated dens was also revealed. Magnetic resonance imaging showed compressed spinal cord at C1 level by the ossification of TLA and AAS. We suggest a mechanism of ossification of TLA as follows: hypertrophied dens and stress to the atlantoaxial joints caused by coalition of atlantooccipital joints could make forward shift of atlas leading to irreducible AAS, and continuous tension given to TLA from irreducible AAS would result in hypertrophied and ossification of TLA

Heritability and Environmental Correlation of Phase Angle with Anthropometric Measurements: A Twin Study

Bioelectrical impedance analysis (BIA)-derived phase angle (PhA) is a valuable parameter to assess physical health. However, the genetic and environmental aspects of PhA are not yet well understood. The present study aimed to estimate the heritability of PhA and investigate the relationships between PhA and anthropometric measurements. PhA and skeletal muscle mass index (SMI) were examined using multi-frequency BIA in 168 Japanese twin volunteers (54 males and 114 females; mean age = 61.0 ± 16.5 years). We estimated the narrow-sense heritability of these parameters and the genetic and environmental relationships between them using a genetic twin modeling. For the PhA, 51% (95% confidence interval: 0.33, 0.64) of the variance was explained by additive genetic effects, and 49% (95% confidence interval: 0.36, 0.67) was explained by unique environmental effects. The heritability of PhA was lower than the height, body weight, and body mass index. PhA shared almost no genetic variation with anthropometric measurements and SMI but shared an environmental variation (14%) with SMI. These findings suggest that the genes affecting PhA are different than those affecting anthropometric measurements and SMI. The correlation between PhA and SMI is caused by common environmental factors

Heritability and Environmental Correlation of Phase Angle with Anthropometric Measurements: A Twin Study

Bioelectrical impedance analysis (BIA)-derived phase angle (PhA) is a valuable parameter to assess physical health. However, the genetic and environmental aspects of PhA are not yet well understood. The present study aimed to estimate the heritability of PhA and investigate the relationships between PhA and anthropometric measurements. PhA and skeletal muscle mass index (SMI) were examined using multi-frequency BIA in 168 Japanese twin volunteers (54 males and 114 females; mean age = 61.0 ± 16.5 years). We estimated the narrow-sense heritability of these parameters and the genetic and environmental relationships between them using a genetic twin modeling. For the PhA, 51% (95% confidence interval: 0.33, 0.64) of the variance was explained by additive genetic effects, and 49% (95% confidence interval: 0.36, 0.67) was explained by unique environmental effects. The heritability of PhA was lower than the height, body weight, and body mass index. PhA shared almost no genetic variation with anthropometric measurements and SMI but shared an environmental variation (14%) with SMI. These findings suggest that the genes affecting PhA are different than those affecting anthropometric measurements and SMI. The correlation between PhA and SMI is caused by common environmental factors

Crucial roles of Robo proteins in midline crossing of cerebellofugal axons and lack of their up-regulation after midline crossing

<p>Abstract</p> <p>Background</p> <p>Robo1, Robo2 and Rig-1 (Robo3), members of the Robo protein family, are candidate receptors for the chemorepellents Slit and are known to play a crucial role in commissural axon guidance in the spinal cord. However, their roles at other axial levels remain unknown. Here we examine expression of Robo proteins by cerebellofugal (CF) commissural axons in the rostral hindbrain and investigate their roles in CF axon pathfinding by analysing Robo knockout mice.</p> <p>Results</p> <p>We analysed the expression of Robo proteins by CF axons originating from deep cerebellar neurons in rodent embryos, focusing on developmental stages of their midline crossing and post-crossing navigation. At the stage of CF axon midline crossing, mRNAs of Robo1 and Robo2 are expressed in the nuclear transitory zone of the cerebellum, where the primordium of the deep cerebellar nuclei are located, supporting the notion that CF axons express Robo1 and Robo2. Indeed, immunohistochemical analysis of CF axons labelled by electroporation to deep cerebellar nuclei neurons indicates that Robo1 protein, and possibly also Robo2 protein, is expressed by CF axons crossing the midline. However, weak or no expression of these proteins is found on the longitudinal portion of CF axons. In <it>Robo1</it>/<it>2 </it>double knockout mice, many CF axons reach the midline but fail to exit it. We find that CF axons express Rig-1 (Robo3) before they reach the midline but not after the longitudinal turn. Consistent with this <it>in vivo </it>observation, axons elicited from a cerebellar explant in co-culture with a floor plate explant express Rig-1. In <it>Rig-1 </it>deficient mouse embryos, CF axons appear to project ipsilaterally without reaching the midline.</p> <p>Conclusion</p> <p>These results indicate that Robo1, Robo2 or both are required for midline exit of CF axons. In contrast, Rig-1 is required for their approach to the midline. However, post-crossing up-regulation of these proteins, which plays an important role in spinal commissural axon guidance, does not appear to be required for the longitudinal navigation of CF axons after midline crossing. Our results illustrate that although common mechanisms operate for midline crossing at different axial levels, significant variation exists in post-crossing navigation.</p

小川・森永・佐藤編著『北海道の企業』合評会 : 備忘録

札幌大学経営学部で展開してきた「現代企業研究会」は,北海道で活躍する企業,北海道でビジネスモデルとして取り上げるべき経営がなされている企業を選び,ケース・スタディを重ねてきた。2005年12月に上梓された『北海道の企業』(北海道大学出版会)はそれら研究会の成果を,大学の講義でも取り上げることができるように産業の概要を前段において「札幌大学経営学部産業経営研究所企業研究シリーズI」としてまとめたものである。2006年3月7日,札幌大学において5名の評者による本書の合評会が催された。1～12章を担当した編著者にはいささか高踏的とも,無い物ねだりともとられる評が加えられたが,多様な批判と本書に対するポジティブな評価とが折り合わさって有意義な合評会であった。そこで,当日の合評会における議論を少しでも多くの方に知っていただき,北海道企業を対象にしたビジネスのケース・スタディとしての本書の意義を分かち合いたい,予定されているシリーズIIの編集・執筆に些かなりともお役に立てるのではないか,また本書を講義で用いる際の参考にもなるのではないか,と愚考し備忘録として活字化することとした。以下,各人のレジュメなどから批評を文章化した。活字化するにあたり収録できなかったケースや逆に重複するところもあるが,当日の雰囲気を味わっていただくために整理は最小限として掲載することとした。その方が批評者の着眼点,個性もわかることと思う。ご寛恕願いたい

The spread of rice to Japan: insights from Bayesian analysis of direct radiocarbon dates and population dynamics in East Asia

The shift from foraging to agriculture as an economic way of life can be influenced by multiple ecological and cultural factors. The introduction of rice cultivation in Japan appears to have facilitated a dietary and cultural transition from the Jomon to the Yayoi cultural repertoire (10th/4th century BCE). Here we examine how rice spread across the Yayoi cultural arena (Kyushu, Shikoku, and Honshu regions) using Bayesian modelling applied to a set of radiocarbon (14C) dates obtained from carbonized rice grains. The combined results of radiocarbon analysis and archaeological data suggest that rice could have appeared in the Central Highlands already in the 11th century BCE when the region was occupied by people of the Final Jomon culture group and was mainly used for ritual purposes. It then appeared in western Japan (northern Kyushu) in the 9th century BCE and continued to disperse discontinuously across eastern Japan. This dispersal pattern likely results from the fusion of Jomon hunter–fisher–gatherer groups in eastern Japan with cultural traits introduced from the Eurasian mainland. The main driving factors for the immigration of early rice farmers into Japan (starting around 1000 BCE) appears to have been sociopolitical. Transformations in China led to the dissemination of rice farmers into the Korean Peninsula about 500 years earlier. The main drivers likely comprised: (i) the eastward expansion of the Shang dynasty (ca. 1600–1400 BCE); (ii) the eastward expansion of the Zhou kingdom, accompanied by the establishment of satellite states, such as Lu (Shandong Province) and Yan (Beijing), following the defeat of the Shang in 1045 BCE; and (iii) the strengthening of local states during the early 8th century BCE after the weakening of the Zhou, due to conflicts with agropastoralists from the Asian steppes. In addition, it is likely that the gradual middle–late Holocene decrease in summer monsoon precipitation negatively affected agricultural yields in the regions located closer to the summer monsoon boundary, such as the middle Yellow River, and thus further fostered the observed population dynamics including the spread of rice farmers to the Korean Peninsula and Japan