1. |
- Namkoong, H, et al.
(author)
-
DOCK2 is involved in the host genetics and biology of severe COVID-19
- 2022
-
In: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 609:7928, s. 754-
-
Journal article (peer-reviewed)abstract
- Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge1–5. Here we conducted a genome-wide association study (GWAS) involving 2,393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3,289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target.
|
|
2. |
- Wang, QBS, et al.
(author)
-
The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force
- 2022
-
In: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1, s. 4830-
-
Journal article (peer-reviewed)abstract
- Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection.
|
|
3. |
|
|
4. |
|
|
5. |
|
|
6. |
- Noguchi, S, et al.
(author)
-
FANTOM5 CAGE profiles of human and mouse samples
- 2017
-
In: Scientific data. - : Springer Science and Business Media LLC. - 2052-4463. ; 4, s. 170112-
-
Journal article (peer-reviewed)abstract
- In the FANTOM5 project, transcription initiation events across the human and mouse genomes were mapped at a single base-pair resolution and their frequencies were monitored by CAGE (Cap Analysis of Gene Expression) coupled with single-molecule sequencing. Approximately three thousands of samples, consisting of a variety of primary cells, tissues, cell lines, and time series samples during cell activation and development, were subjected to a uniform pipeline of CAGE data production. The analysis pipeline started by measuring RNA extracts to assess their quality, and continued to CAGE library production by using a robotic or a manual workflow, single molecule sequencing, and computational processing to generate frequencies of transcription initiation. Resulting data represents the consequence of transcriptional regulation in each analyzed state of mammalian cells. Non-overlapping peaks over the CAGE profiles, approximately 200,000 and 150,000 peaks for the human and mouse genomes, were identified and annotated to provide precise location of known promoters as well as novel ones, and to quantify their activities.
|
|
7. |
- Papadopoulos, N G, et al.
(author)
-
International consensus on (ICON) pediatric asthma.
- 2012
-
In: Allergy. - : Wiley. - 1398-9995 .- 0105-4538. ; 67:8, s. 976-97
-
Journal article (peer-reviewed)abstract
- Asthma is the most common chronic lower respiratory disease in childhood throughout the world. Several guidelines and/or consensus documents are available to support medical decisions on pediatric asthma. Although there is no doubt that the use of common systematic approaches for management can considerably improve outcomes, dissemination and implementation of these are still major challenges. Consequently, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), recently formed by the EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus on (ICON) Pediatric Asthma. The purpose of this document is to highlight the key messages that are common to many of the existing guidelines, while critically reviewing and commenting on any differences, thus providing a concise reference. The principles of pediatric asthma management are generally accepted. Overall, the treatment goal is disease control. To achieve this, patients and their parents should be educated to optimally manage the disease, in collaboration with healthcare professionals. Identification and avoidance of triggers is also of significant importance. Assessment and monitoring should be performed regularly to re-evaluate and fine-tune treatment. Pharmacotherapy is the cornerstone of treatment. The optimal use of medication can, in most cases, help patients control symptoms and reduce the risk for future morbidity. The management of exacerbations is a major consideration, independent of chronic treatment. There is a trend toward considering phenotype-specific treatment choices; however, this goal has not yet been achieved.
|
|
8. |
|
|
9. |
- Pennells, Lisa, et al.
(author)
-
Equalization of four cardiovascular risk algorithms after systematic recalibration : individual-participant meta-analysis of 86 prospective studies
- 2019
-
In: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 40:7, s. 621-
-
Journal article (peer-reviewed)abstract
- Aims: There is debate about the optimum algorithm for cardiovascular disease (CVD) risk estimation. We conducted head-to-head comparisons of four algorithms recommended by primary prevention guidelines, before and after ‘recalibration’, a method that adapts risk algorithms to take account of differences in the risk characteristics of the populations being studied.Methods and results: Using individual-participant data on 360 737 participants without CVD at baseline in 86 prospective studies from 22 countries, we compared the Framingham risk score (FRS), Systematic COronary Risk Evaluation (SCORE), pooled cohort equations (PCE), and Reynolds risk score (RRS). We calculated measures of risk discrimination and calibration, and modelled clinical implications of initiating statin therapy in people judged to be at ‘high’ 10 year CVD risk. Original risk algorithms were recalibrated using the risk factor profile and CVD incidence of target populations. The four algorithms had similar risk discrimination. Before recalibration, FRS, SCORE, and PCE over-predicted CVD risk on average by 10%, 52%, and 41%, respectively, whereas RRS under-predicted by 10%. Original versions of algorithms classified 29–39% of individuals aged ≥40 years as high risk. By contrast, recalibration reduced this proportion to 22–24% for every algorithm. We estimated that to prevent one CVD event, it would be necessary to initiate statin therapy in 44–51 such individuals using original algorithms, in contrast to 37–39 individuals with recalibrated algorithms.Conclusion: Before recalibration, the clinical performance of four widely used CVD risk algorithms varied substantially. By contrast, simple recalibration nearly equalized their performance and improved modelled targeting of preventive action to clinical need.
|
|
10. |
- Gono, Y., et al.
(author)
-
Systematics of high-spin isomers in N=83 isotones and a high-spin isomer beam
- 2002
-
In: European Physical Journal A. - 1434-6001 .- 1434-601X. ; 13:02-jan, s. 5-8
-
Journal article (peer-reviewed)abstract
- Isomers in N = 83 isotones of Z = 60 66 were studied systematically. Their spins and parities arc,49/2(+) and 27(+) for odd and odd-odd nuclei, respectively. Nearly constant excitation energies of these isomers indicated a decrease of a Z = 64 shell gap energy as Z decreases from 64 to 60 within the framework of a deformed independent-particle model (DIPM). Their configurations are [v(f(tau/2)h(9/2)i(13/2)), pi(h(11/2))(2)](49/2+) and [v(f(7/2)h(9/2)i(13/2)), pi(h(11/2))(2)(d(5/2))(-1)](27+) for odd and odd-odd nuclei, respectively. The shape of the yrast status changes suddenly at spin 49/2(odd) and 27(odd-odd) from a near spherical to an oblate shape. Transitions from isomers are highly hindered because of the shape changes. They may be categorized to be shape isomers. The development of a secondary beam produced by using these high-spin isomers is also described.
|
|
11. |
- Kishida, T., et al.
(author)
-
High-spin isomeric beam line
- 2002
-
In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 484:03-jan, s. 45-55
-
Journal article (peer-reviewed)abstract
- A high-spin isomeric beam line has been constructed at RIKEN based on the inverse kinematics of fusion-evaporation reactions. The beam line provides high-spin isomers as secondary beams, whose intensity is more than 10(5) sec(-1). The characteristics and the present status of the beam line are described.
|
|
12. |
|
|
13. |
- Morikawa, H, et al.
(author)
-
Differential roles of epigenetic changes and Foxp3 expression in regulatory T cell-specific transcriptional regulation
- 2014
-
In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490. ; 111:14, s. 5289-5294
-
Journal article (peer-reviewed)abstract
- Naturally occurring regulatory T (Treg) cells, which specifically express the transcription factor forkhead box P3 (Foxp3), are engaged in the maintenance of immunological self-tolerance and homeostasis. By transcriptional start site cluster analysis, we assessed here how genome-wide patterns of DNA methylation or Foxp3 binding sites were associated with Treg-specific gene expression. We found that Treg-specific DNA hypomethylated regions were closely associated with Treg up-regulated transcriptional start site clusters, whereas Foxp3 binding regions had no significant correlation with either up- or down-regulated clusters in nonactivated Treg cells. However, in activated Treg cells, Foxp3 binding regions showed a strong correlation with down-regulated clusters. In accordance with these findings, the above two features of activation-dependent gene regulation in Treg cells tend to occur at different locations in the genome. The results collectively indicate that Treg-specific DNA hypomethylation is instrumental in gene up-regulation in steady state Treg cells, whereas Foxp3 down-regulates the expression of its target genes in activated Treg cells. Thus, the two events seem to play distinct but complementary roles in Treg-specific gene expression.
|
|
14. |
|
|
15. |
|
|
16. |
- Wang, S. Y., et al.
(author)
-
Band structures in I-123
- 2006
-
In: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 32:3, s. 283-294
-
Journal article (peer-reviewed)abstract
- Excited states of I-123 were populated via the Cd-116(N-14, alpha 3n) reaction at 65 MeV. The resultant gamma-rays were detected using standard gamma-ray spectroscopic techniques with the NORDBALL detector array. Two previously known positive-parity Delta I = 2 sequences have been extended up to 31/2(+) and 41/2(+). In addition, a number of Delta I = 1 transitions linking the two Delta I = 2 sequences have been observed. It is suggested that both Delta I = 2 sequences are based on a common configuration. This Delta I = 1 band is proposed to be built predominantly on the 97/2[404]7/2(+) oblate configuration, based on the energylevel spectra, B(MI)/B(E2) ratios and the theoretical predictions from the particle-rotor model. The previously identified Delta I = 1 rotational band built on the prolate g(9/2)[404]9/2(+) orbital has also been extended to higher spins. Another previously identified but weakly populated Delta I = 1 band is confirmed and is proposed to be built on the d(5/2)[413]5/2' configuration with the ground state of I-123 as the bandhead.
|
|
17. |
- Wang, S. Y., et al.
(author)
-
High-spin level scheme of Cs-126
- 2004
-
In: Gaoneng wuli yu he wuli. - 0254-3052. ; 28:5, s. 491-494
-
Journal article (peer-reviewed)abstract
- High-spin states of Cs-126 have been populated via the Cd-116(N-14, 4n) Cs-126 reaction. The experiment was performed at Niels Bohr Institute in Denmark in 1991. After careful data analysis, most of the previously-known bands have been pushed up to much higher spins and 3 new rotational sequences have been identified. Spin, parity and configuration assignments are tentatively proposed for all of the observed bands.
|
|
18. |
- Wang, S. Y., et al.
(author)
-
Structure of the pi g(7/2) 404 7/2(+) band in odd proton nucleus I-123
- 2004
-
In: Chinese Physics Letters. - 0256-307X .- 1741-3540. ; 21:6, s. 1024-1026
-
Journal article (peer-reviewed)abstract
- High spin states of the odd proton nucleus I-123 have been populated in the reaction Cd-116(N-14, 5n2p) at a beam energy of 65 MeV. Two previously known positive-parity DeltaI = 2 sequences have been extended up to 31/2(+) and 41/2(+). In addition, a number of DeltaI = 1 transitions linking the two DeltaI = 2 sequences have been observed. It is suggested that both the DeltaI = 2 sequences are built upon the oblate pi(g) (7/2)[404]7/2(+) Nilsson configuration.
|
|
19. |
- Arakawa, H, et al.
(author)
-
Airway responses following intradermal sensitization to different types of allergens: ovalbumin, trimellitic anhydride and Dermatophagoides farinae
- 1995
-
In: International Archives of Allergy and Immunology. - 1423-0097. ; 108:3, s. 274-280
-
Journal article (peer-reviewed)abstract
- Sensitization of guinea pigs by intradermal injections of the occupational allergen trimellitic anhydride (TMA) in oily vehicle has been shown to be very reproducible. We studied the effect of intradermal sensitization with ovalbumin (OA) in oily vehicle on immune and airway responses in guinea pigs. We also compared airway responses to trimellitic anhydride or Dermatophagoides farinae (DF; mite) with those to OA in guinea pigs intradermally sensitized to respective allergens. Three to four weeks after sensitization, the animals were challenged with intratracheal instillation of these allergens. Intradermal injections with OA developed dose-dependently specific IgG1 antibodies to OA demonstrated by ELISA. In animals sensitized with different doses of OA in corn oil vehicle, a challenge with OA induced a reversely dose-dependent airflow obstruction and airway plasma exudation. In contrast, animals sensitized with OA in saline vehicle had dose-dependent airway responses to OA. Challenge with OA caused an immediate peak and subsequently persistent airflow obstruction, whereas this response to either TMA guinea pig serum albumin or Df was slowly progressive in animals sensitized to respective allergens. The animals sensitized to TMA or Df may show a different profile of airway responses following the challenge compared to OA. Intradermal sensitization may be a valuable method of sensitization for the development of an animal model of airway allergy to different types of allergens, including chemicals or mites.
|
|
20. |
|
|
21. |
- Fernandes, SJ, et al.
(author)
-
Non-parametric combination analysis of multiple data types enables detection of novel regulatory mechanisms in T cells of multiple sclerosis patients
- 2019
-
In: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1, s. 11996-
-
Journal article (peer-reviewed)abstract
- Multiple Sclerosis (MS) is an autoimmune disease of the central nervous system with prominent neurodegenerative components. The triggering and progression of MS is associated with transcriptional and epigenetic alterations in several tissues, including peripheral blood. The combined influence of transcriptional and epigenetic changes associated with MS has not been assessed in the same individuals. Here we generated paired transcriptomic (RNA-seq) and DNA methylation (Illumina 450 K array) profiles of CD4+ and CD8+ T cells (CD4, CD8), using clinically accessible blood from healthy donors and MS patients in the initial relapsing-remitting and subsequent secondary-progressive stage. By integrating the output of a differential expression test with a permutation-based non-parametric combination methodology, we identified 149 differentially expressed (DE) genes in both CD4 and CD8 cells collected from MS patients. Moreover, by leveraging the methylation-dependent regulation of gene expression, we identified the gene SH3YL1, which displayed significant correlated expression and methylation changes in MS patients. Importantly, silencing of SH3YL1 in primary human CD4 cells demonstrated its influence on T cell activation. Collectively, our strategy based on paired sampling of several cell-types provides a novel approach to increase sensitivity for identifying shared mechanisms altered in CD4 and CD8 cells of relevance in MS in small sized clinical materials.
|
|
22. |
|
|
23. |
- Hosaka, K, et al.
(author)
-
Therapeutic paradigm of dual targeting VEGF and PDGF for effectively treating FGF-2 off-target tumors
- 2020
-
In: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11:1, s. 3704-
-
Journal article (peer-reviewed)abstract
- FGF-2 displays multifarious functions in regulation of angiogenesis and vascular remodeling. However, effective drugs for treating FGF-2+ tumors are unavailable. Here we show that FGF-2 modulates tumor vessels by recruiting NG2+ pricytes onto tumor microvessels through a PDGFRβ-dependent mechanism. FGF-2+ tumors are intrinsically resistant to clinically available drugs targeting VEGF and PDGF. Surprisingly, dual targeting the VEGF and PDGF signaling produces a superior antitumor effect in FGF-2+ breast cancer and fibrosarcoma models. Mechanistically, inhibition of PDGFRβ ablates FGF-2-recruited perivascular coverage, exposing anti-VEGF agents to inhibit vascular sprouting. These findings show that the off-target FGF-2 is a resistant biomarker for anti-VEGF and anti-PDGF monotherapy, but a highly beneficial marker for combination therapy. Our data shed light on mechanistic interactions between various angiogenic and remodeling factors in tumor neovascularization. Optimization of antiangiogenic drugs with different principles could produce therapeutic benefits for treating their resistant off-target cancers.
|
|
24. |
- Konishi, T, et al.
(author)
-
Electronic structure of the strongly hybridized ferromagnet CeFe2
- 2000
-
In: PHYSICAL REVIEW B. - : AMERICAN PHYSICAL SOC. - 0163-1829. ; 62:21, s. 14304-14312
-
Journal article (peer-reviewed)abstract
- We report on results from high-energy spectroscopic measurements on CeFe2, a system of particular interest due to its anomalous ferromagnetism with an unusually low Curie temperature and small magnetization compared to the other rare-earth iron Laves phas
|
|
25. |
- Konishi, T, et al.
(author)
-
Photoemission and inverse-photoemission study of ferromagnetic valence fluctuating system CeFe2
- 1998
-
In: JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA. - : ELSEVIER SCIENCE BV. - 0368-2048. ; 88, s. 303-307
-
Journal article (other academic/artistic)abstract
- Various electron-spectroscopic results including core-level X-ray photoemission, X-ray absorption, Ce 3d-4f and 4d-4f resonant photoemission, and inverse-photoemission spectroscopy on the valence fluctuating ferromagnet CeFe2 are presented and analyzed wi
|
|
26. |
|
|
27. |
- Pour, SR, et al.
(author)
-
Exhaustion of CD4+ T-cells mediated by the Kynurenine Pathway in Melanoma
- 2019
-
In: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1, s. 12150-
-
Journal article (peer-reviewed)abstract
- Kynurenine pathway (KP) activation by the enzymatic activity of indoleamine 2,3-dioxygenase1 (IDO1) and kynurenine (KYN) production represents an attractive target for reducing tumour progression and improving anti-tumour immunity in multiple cancers. However, immunomodulatory properties of other KP metabolites such as 3-hydroxy kynurenine (3-HK) and kynurenic acid (KYNA) are poorly understood. The association of the kynurenine metabolic pathway with T-cell status in the tumour microenvironment were characterized, using gene expression data of 368 cutaneous skin melanoma (SKCM) patients from the TCGA cohort. Based on the identified correlations, we characterized the production of KYN, 3-HK, and KYNA in vitro using melanoma-derived cell lines and primary CD4+ CD25− T-cells. Activation of the CD4+ T-cells produced IFNγ, which yielded increased levels of KYN and KYNA. Concurrently, kynurenine 3-monooxygenase (KMO) expression and proliferation of CD4+ T-cells were reduced, whereas exhaustion markers such as PD-L1, AHR, FOXP3, and CTLA4 were increased. Additionally, an analysis of the correlation network reconstructed using TCGA-SKCM emphasized KMO and KYNU with high variability among BRAF wild-type compared with V600E, which underscored their role in distinct CD4+ T-cell behavior in tumour immunity. Our results suggest that, in addition to IDO1, there is an alternative immune regulatory mechanism associated with the lower KMO expression and the higher KYNA production, which contributes to dysfunctional effector CD4+ T-cell response.
|
|
28. |
- Richter, Anne, et al.
(author)
-
EGFL7 Mediates BMP9-Induced Sprouting Angiogenesis of Endothelial Cells Derived from Human Embryonic Stem Cells
- 2019
-
In: Stem Cell Reports. - : Elsevier BV. - 2213-6711. ; 12:6, s. 1250-1259
-
Journal article (peer-reviewed)abstract
- Human embryonic stem cells (hESCs) are instrumental in characterizing the molecular mechanisms of human vascular development and disease. Bone morphogenetic proteins (BMPs) play a pivotal role in cardiovascular development in mice, but their importance for vascular cells derived from hESCs has not yet been fully explored. Here, we demonstrate that BMP9 promotes, via its receptor ALK1 and SMAD1/5 activation, sprouting angiogenesis of hESC-derived endothelial cells. We show that the secreted angiogenic factor epidermal growth factor-like domain 7 (EGFL7) is a downstream target of BMP9-SMAD1/5-mediated signaling, and that EGFL7 promotes expansion of endothelium via interference with NOTCH signaling, activation of ERK, and remodeling of the extracellular matrix. CRISPR/Cas9-mediated deletion of EGFL7 highlights the critical role of EGFL7 in BMP9-induced endothelial sprouting and the promotion of angiogenesis. Our study illustrates the complex role of the BMP family in orchestrating hESC vascular development and endothelial sprouting.
|
|
29. |
- Ruhrmann, S, et al.
(author)
-
Hypermethylation of MIR21 in CD4+ T cells from patients with relapsing-remitting multiple sclerosis associates with lower miRNA-21 levels and concomitant up-regulation of its target genes
- 2018
-
In: Multiple sclerosis (Houndmills, Basingstoke, England). - : SAGE Publications. - 1477-0970 .- 1352-4585. ; 24:10, s. 1288-1300
-
Journal article (peer-reviewed)abstract
- Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system caused by genetic and environmental factors. DNA methylation, an epigenetic mechanism that controls genome activity, may provide a link between genetic and environmental risk factors. Objective: We sought to identify DNA methylation changes in CD4+ T cells in patients with relapsing-remitting (RR-MS) and secondary-progressive (SP-MS) disease and healthy controls (HC). Methods: We performed DNA methylation analysis in CD4+ T cells from RR-MS, SP-MS, and HC and associated identified changes with the nearby risk allele, smoking, age, and gene expression. Results: We observed significant methylation differences in the VMP1/MIR21 locus, with RR-MS displaying higher methylation compared to SP-MS and HC. VMP1/MIR21 methylation did not correlate with a known MS risk variant in VMP1 or smoking but displayed a significant negative correlation with age and the levels of mature miR-21 in CD4+ T cells. Accordingly, RR-MS displayed lower levels of miR-21 compared to SP-MS, which might reflect differences in age between the groups, and healthy individuals and a significant enrichment of up-regulated miR-21 target genes. Conclusion: Disease-related changes in epigenetic marking of MIR21 in RR-MS lead to differences in miR-21 expression with a consequence on miR-21 target genes.
|
|
30. |
|
|
31. |
- SUGAWARA, M, et al.
(author)
-
HIGH-SPIN STATES IN RB-79
- 1995
-
In: JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN. - : PHYSICAL SOCIETY JAPAN KIKAI-SHINKO BUILDING. ; 64:1
-
Other publication (other academic/artistic)
|
|
32. |
|
|
33. |
- Tamagawa, T., et al.
(author)
-
Correlation between musculoskeletal structure of the hand and primate locomotion: Morphometric and mechanical analysis in prehension using the cross- and triple-ratios
- 2020
-
In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 15:5
-
Journal article (peer-reviewed)abstract
- Biometric ratios of the relative length of the rays in the hand have been analyzed between primate species in the light of their hand function or phylogeny. However, how relative lengths among phalanges are mechanically linked to the grasping function of primates with different locomotor behaviors remains unclear. To clarify this, we calculated cross and triple-ratios, which are related to the torque distribution, and the torque generation mode at different joint angles using the lengths of the phalanges and metacarpal bones in 52 primates belonging to 25 species. The torque exerted on the finger joint and traction force of the flexor tendons necessary for a cylindrical grip and a suspensory hand posture were calculated using the moment arm of flexor tendons measured on magnetic resonance images, and were compared among Hylobates spp., Ateles sp., and Papio hamadryas. Finally, the torques calculated from the model were validated by a mechanical study detecting the force exerted on the phalanx by pulling the digital flexor muscles during suspension in these three species. Canonical discriminant analysis of cross and triple-ratios classified primates almost in accordance with their current classification based on locomotor behavior. The traction force was markedly reduced with flexion of the MCP joint parallel to the torque in brachiating primates; this was notably lower in the terrestrial quadrupedal primates than in the arboreal primates at mild flexion. Our mechanical study supported these features in the torque and traction force generation efficiencies. Our results suggest that suspensory or terrestrial quadrupedal primates have hand structures that can exert more torque at a suspensory posture, or palmigrade and digitigrade locomotion, respectively. Furthermore, our study suggests availability of the cross and triple-ratios as one of the indicators to estimate the hand function from the skeletal structure.
|
|