scholarly journals On the Development of Sesamoid Bones

2018 ◽  
Author(s):  
Shai Eyal ◽  
Sarah Rubin ◽  
Sharon Krief ◽  
Lihi Levin ◽  
Elazar Zelzer
Keyword(s):  
Bone Development ◽  
Developmental Model ◽  
Mechanical Stimuli ◽  
Synovial Joint ◽  
Sesamoid Bone ◽  
Special Group ◽  
Sesamoid Bones ◽  
And Function ◽  
High Degree ◽  
Anatomical Connection

ABSTRACTSesamoid bones are a special group of small auxiliary bones that form in proximity to joints and contribute to their stability and function. Sesamoid bones display high degree of variability in size, location, penetrance and anatomical connection to the main skeleton across vertebrate species. Therefore, providing a comprehensive developmental model or classification system for sesamoid bones is challenging. Here, we examine the developmental mechanisms of three anatomically different sesamoid bones, namely patella, lateral fabella and digit sesamoids. Through a comprehensive comparative analysis at the cellular, molecular and mechanical levels, we demonstrate that all three types of sesamoid bones originated from Sox9+/Scx+ progenitors under the regulation of TGFβ and independent of mechanical stimuli from muscles. We show that BMP4 was necessary specifically for differentiation of patella but not of lateral fabella or digit sesamoids, whereas BMP2 regulated the growth of all examined sesamoids. Next, we show that whereas patella and digit sesamoids initially formed in juxtaposition to long bones, the lateral fabella formed independently at a distance. Finally, we provide evidence suggesting that while patella detached from the femur by formation of a synovial joint, digit sesamoids detached from the phalanx by a fibrocartilage joint. Collectively, these findings highlight both common and divergent molecular and mechanical features of sesamoid bone development, thereby advancing our understanding of their evolutionary plasticity.

scholarly journals Three-dimensional anatomy of the knee joint of ostriches (Struthio camelus)

2014 ◽  
Author(s):  
Kyle P Chadwick ◽  
Sophie Regnault ◽  
Vivian Allen ◽  
John R. Hutchinson
Keyword(s):  
Knee Joint ◽  
Bone Development ◽  
Three Dimensional ◽  
Anatomical Study ◽  
Sesamoid Bone ◽  
Struthio Camelus ◽  
Future Studies ◽  
Biomechanical Loading ◽  
Sesamoid Bones

The three-dimensional anatomy of the ostrich (Struthio camelus) knee (femorotibial, femorofibular, and femoropatellar) joint has scarcely been studied, and could elucidate certain mechanobiological properties of sesamoid bones. The adult ostrich is unique in that it has double patellae, while another similar ratite bird, the emu, has none. Understanding why these patellae form and what purpose they may serve is dually important for future studies on ratites as well as understanding mechanobiological characteristics of sesamoid bone development. For this purpose, we present a three-dimensional anatomical study of the ostrich knee joint, detailing osteology, ligaments and menisci, and myology. We have identified seven muscles which connect to the two patellae and compare our findings to past descriptions. These descriptions can be used to further study the biomechanical loading and implications of the double patella in the ostrich.

scholarly journals Three-dimensional anatomy of the knee joint of ostriches (Struthio camelus)

2014 ◽  
Author(s):  
Kyle P Chadwick ◽  
Sophie Regnault ◽  
Vivian Allen ◽  
John R. Hutchinson
Keyword(s):  
Knee Joint ◽  
Bone Development ◽  
Three Dimensional ◽  
Anatomical Study ◽  
Sesamoid Bone ◽  
Struthio Camelus ◽  
Future Studies ◽  
Biomechanical Loading ◽  
Sesamoid Bones

The three-dimensional anatomy of the ostrich (Struthio camelus) knee (femorotibial, femorofibular, and femoropatellar) joint has scarcely been studied, and could elucidate certain mechanobiological properties of sesamoid bones. The adult ostrich is unique in that it has double patellae, while another similar ratite bird, the emu, has none. Understanding why these patellae form and what purpose they may serve is dually important for future studies on ratites as well as understanding mechanobiological characteristics of sesamoid bone development. For this purpose, we present a three-dimensional anatomical study of the ostrich knee joint, detailing osteology, ligaments and menisci, and myology. We have identified seven muscles which connect to the two patellae and compare our findings to past descriptions. These descriptions can be used to further study the biomechanical loading and implications of the double patella in the ostrich.

Emotion Dysregulation and Externalizing Spectrum Disorders

2019 ◽  
pp. 236-247
Author(s):  
Tiffany M. Shader ◽  
Theodore P. Beauchaine
Keyword(s):  
Emotion Dysregulation ◽  
Externalizing Disorders ◽  
Developmental Model ◽  
Peer Influences ◽  
Neighborhood Violence ◽  
Number Of Children ◽  
Hyperactivity Disorder ◽  
Oppositional Defiant ◽  
Trait Impulsivity ◽  
And Function

As described in the literature for many years, a sizable number of children with hyperactive-impulsive and combined subtypes/presentations of attention-deficit/hyperactivity disorder (ADHD)—especially males—progress to more serious externalizing syndromes across development. Such outcomes include oppositional defiant disorder, conduct problems, delinquency, substance use disorders, and in some cases antisocial personality disorder, incarceration, and recidivism. This chapter summarizes a developmental model that emphasizes different contributions of trait impulsivity, a highly heritable, subcortically mediated vulnerability, versus emotion dysregulation, a highly socialized, cortically mediated vulnerability, to externalizing progression. According to this perspective, trait impulsivity confers vulnerability to all externalizing disorders, but this vulnerability is unlikely to progress beyond ADHD in protective environments. In contrast, for children who are reared under conditions of adversity—including poverty, family violence, deviant peer influences, and neighborhood violence/criminality—neurodevelopment of prefrontal cortex structure and function is compromised, resulting in failures to achieve age-expected gains in emotion regulation and other forms of executive control. For these children, subcortical vulnerabilities to trait impulsivity are amplified by deficient cortical modulation, which facilitates progression along the externalizing spectrum.

scholarly journals The enigmatic ribosomal stalk

2018 ◽  
Vol 51 ◽  
Author(s):  
Anders Liljas ◽  
Suparna Sanyal
Keyword(s):  
Early Phase ◽  
Ribosomal Subunit ◽  
Structure And Function ◽  
Large Ribosomal Subunit ◽  
Translation Factors ◽  
Ribosomal Stalk ◽  
And Function ◽  
High Degree

Abstract The large ribosomal subunit has a distinct feature, the stalk, extending outside the ribosome. In bacteria it is called the L12 stalk. The base of the stalk is protein uL10 to which two or three dimers of proteins bL12 bind. In archea and eukarya P1 and P2 proteins constitute the stalk. All these extending proteins, that have a high degree of flexibility due to a hinge between their N- and C-terminal parts, are essential for proper functionalization of some of the translation factors. The role of the stalk proteins has remained enigmatic for decades but is gradually approaching an understanding. In this review we summarise the knowhow about the structure and function of the ribosomal stalk till date starting from the early phase of ribosome research.

Herbaceous monocot plant form and function along a tropical rain-forest light gradient: a reversal of dicot strategy

2009 ◽  
Vol 25 (1) ◽  
pp. 103-106 ◽  
Author(s):  
Nathan G. Swenson
Keyword(s):  
Tropical Forests ◽  
Environmental Gradients ◽  
Plant Performance ◽  
Seed Plants ◽  
Form And Function ◽  
Light Gradient ◽  
Whole Plant ◽  
Plant Form ◽  
And Function ◽  
High Degree

Whole plant form and function vary spectacularly across the seed plants. In recent years, plant evolutionary ecologists have begun to document this diversity on large geographic scales by analysing ‘functional traits’ that are indicative of whole plant performance across environmental gradients (Swenson & Enquist 2007, Wright et al. 2004). Despite the high degree of functional diversity in tropical forests, convergence in function does occur locally along successional or light gradients (Bazzaz & Pickett 1980, Swaine & Whitmore 1988).

scholarly journals Histological and morphometric study of the uterus of the lowland bison

2017 ◽  
Vol 73 (10) ◽  
pp. 661-665
Author(s):  
Katarzyna Olbrych ◽  
Karolina Barszcz ◽  
Bartłomiej Bartyzel ◽  
Tomasz Szara ◽  
Marta Kupczyńska
Keyword(s):  
Morphometric Study ◽  
European Bison ◽  
Histological Structure ◽  
Group I ◽  
Epithelium Thickness ◽  
Polish Law ◽  
And Function ◽  
High Degree ◽  
Sexually Mature ◽  
Degree Of Similarity

Summary The European bison belongs to endangered species. Its restitution requires a complete knowledge of the structure and function of its genital organs. The aim of this study was a histological and morphometric examination of the uterus of immature and adult females. Material for the study came from 55 females living in the Białowieża Forest. According to the Polish law, the post mortem use of tissues does not require an approval from an ethics committee. The animals were divided into 2 groups: group I included 36 prepubertal females aged from 2 months to 1.5 years, while group II consisted of 19 sexually mature females aged 2 to 20 years. The samples were stained with haematoxylin and eosin (H&E). Histological and morphometric examinations included measurements of the height of the epithelium, thickness of the endometrium, thickness of the myometrium, thickness of the inner and outer muscular layers, and thickness of the perimetrium. The results were analyzed using the STATISTICA 12.0™ software. Statistically significant differences were found between the two groups in all morphometric parameters examined. The results revealed a high degree of similarity of the histological structure of the uterus between European bison and domestic cattle.

scholarly journals Mechanosensitive Ion Channel Piezo1 Regulates Myocyte Fusion during Skeletal Myogenesis

2020 ◽  
Author(s):  
Huascar Pedro Ortuste Quiroga ◽  
Shingo Yokoyama ◽  
Massimo Ganassi ◽  
Kodai Nakamura ◽  
Tomohiro Yamashita ◽  
...  
Keyword(s):  
Ion Channel ◽  
Molecular Mechanisms ◽  
Myoblast Fusion ◽  
Mechanical Stimuli ◽  
Muscle Satellite Cell ◽  
Myotube Formation ◽  
Mechanosensitive Ion Channel ◽  
And Function ◽  
Sirna Knockdown

AbstractMechanical stimuli such as stretch and resistance training are essential to regulate growth and function of skeletal muscle. However, the molecular mechanisms involved in sensing mechanical stress remain unclear. Here, the purpose of this study was to investigate the role of the mechanosensitive ion channel Piezo1 during myogenic progression. Muscle satellite cell-derived myoblasts and myotubes were modified with stretch, siRNA knockdown and agonist-induced activation of Piezo1. Direct manipulation of Piezo1 modulates terminal myogenic progression. Piezo1 knockdown suppressed myoblast fusion during myotube formation and maturation. This was accompanied by downregulation of the fusogenic protein Myomaker. Piezo1 knockdown also lowered Ca2+ influx in response to stretch. Conversely Piezo1 activation stimulated fusion and increased Ca2+ influx in response to stretch. These evidences indicate that Piezo1 is essential for myotube formation and maturation, which may have implications for msucular dystrophy prevention through its role as a mechanosensitive Ca2+ channel.

Distribution and function of the lethal of scute gene product during early neurogenesis in Drosophila

Development ◽  
1991 ◽  
Vol 113 (2) ◽  
pp. 445-454 ◽  
Author(s):  
M.D. Martin-Bermudo ◽  
C. Martinez ◽  
A. Rodriguez ◽  
F. Jimenez
Keyword(s):  
Central Nervous System ◽  
Drosophila Embryo ◽  
Fushi Tarazu ◽  
Phenotypic Analysis ◽  
Neuronal Identity ◽  
The Central Nervous System ◽  
Early Neurogenesis ◽  
And Function ◽  
High Degree ◽  
Peripheral Sensory

Genes of the achaete-scute complex (ASC) participate in the formation of the central nervous system in the Drosophila embryo. Previous genetic analyses have indicated that lethal of scute (l'sc) is the most important gene of the complex in that process. We have obtained antibodies against the l'sc protein to study the expression of the gene during early neurogenesis. The protein is found in groups of embryonic neuroectodermal cells, analogous to the proneural clusters that precede the appearance of precursors of peripheral sensory organs in imaginal epithelia. The groups appear in different regions of the neuroectoderm, accompanying the three successive waves of neuroblast segregation. Most neuroblasts delaminate from these clusters and express position-specific levels of l'sc protein. No significant differences have been found between the distribution of l'sc RNA and protein. Phenotypic analysis of a l'sc deficiency has shown that the gene is required for neuroblast commitment, although this requirement is less widespread than the domain of l'sc expression, suggesting a high degree of redundancy in the function of genes that participate in the process of neuroblast segregation. The ASC genes have been postulated to play a role in the control of NB identity, revealed by the generation of a defined lineage of identifiable neurons. However, our study in l'sc mutants of the expression of fushi tarazu, engrailed, and even-skipped, used as markers of neuronal identity, has not provided evidence to support this hypothesis.

Subunit δ of Chloroplast F0F1 ATPase and OSCP of Mitochondrial F0F1 ATPase: a Comparison by CD-Spectroscopy

1991 ◽  
Vol 46 (9-10) ◽  
pp. 759-764 ◽  
Author(s):  
Siegfried Engelbrecht ◽  
Jennifer Reed ◽  
François Penin ◽  
Danièle C. Gautheron ◽  
Wolfgang Junge
Keyword(s):  
Primary Structure ◽  
Tertiary Structure ◽  
Atp Synthesis ◽  
Structural Similarity ◽  
Cd Spectroscopy ◽  
Α Helix ◽  
And Function ◽  
High Degree ◽  
Very High ◽  
Secondary And Tertiary Structure

Abstract CD spectra have been recorded with subunit δ from chloroplast CF0CF1 and with OSCP from mitochondrial MF0MF1. These subunits are supposed to act similarly at the interface between proton transport through the F0-portion and ATP-synthesis in the F1-portion of their respective F0F1-ATPase. Evaluation of the data for both proteins revealed a very high α-helix content of -85% and practically no β-sheets. Despite their low homology on the primary structure level (23% identity) and their different electrostatic properties (pl-values differ by 3 units), spinach δ and porcine OSCP are indistinguishable with respect to their secondary structure as measured by CD. Prediction and analysis of consensual a-helices even in poorly conserved regions indicate α high degree of structural similarity between chloroplast δ and OSCP. In view of the topology and function of δ and OSCP in intact F0F1 these findings are interpreted to indicate the dominance of secondary and tertiary structure over the primary structure in their supposed function between proton flow and ATP-synthesis.

The Rare Lesser Metatarsal Bipartite Sesamoid

2017 ◽  
Vol 107 (6) ◽  
pp. 548-550
Author(s):  
Christopher R. Hood ◽  
Jason R. Miller ◽  
Stephanie Eldridge ◽  
Matthew Tran
Keyword(s):  
Incidental Findings ◽  
Rare Case ◽  
Previous Literature ◽  
Sesamoid Bone ◽  
Accessory Ossicles ◽  
Sesamoid Bones

Sesamoid bones and accessory ossicles are common incidental findings on radiographs. These can occasionally become symptomatic, usually after a precipitating event such as an injury or overuse, or they can be incidental findings unrelated to the presenting pathology. The aim of this study was to highlight a rare case of a bipartite fifth metatarsal sesamoid bone and to review previous literature regarding sesamoid bones and accessory ossicles.

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