33 research outputs found

    Assessment of Humeral Retroversion Angle in Baseball Players: A Chronological Study

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    The objective of this study was to compare the humeral retroversion angles (HRA) between baseball players, including children, and those without a history of playing baseball, clarify the characteristics of the HRA in baseball players, and to determine whether or not chronological changes of the HRA are affected by a throwing motion. We studied 32 young baseball players (Group A), 10 elementary and junior high school students who had never played competitive overhead throwing sports (Group B), 65 adult baseball players who had been playing baseball since childhood in a little league or boy\u27s baseball team (Group C), and 11 adults who had never played competitive overhead throwing sports such as baseball or handball (Group D). Computed tomography of both humeri in these subjects was taken with a 5mm slice thickness. For the measurement of HRA, slices from the center of the humeral head and slices from the humeral epicondyle were examined. In baseball players, the mean HRA on the throwing side was larger than that on the non-throwing side, regardless of age and carrier. The HRAs of the elementary and junior high school baseball players as well as those of adult baseball players were larger on the throwing side. The HRA of the throwing side was significantly greater than that of the non-throwing side in both groups of baseball players. Furthermore, the mean HRA on the throwing side of young baseball players was significantly larger than that of adult baseball players, suggesting that the adaptive bony change of the humerus was caused by throwing stress and might occur in the early formative years of a player\u27s career

    Ruptured basilar artery aneurysm causing isolated bilateral abducens nerve palsy

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    症例は54歳,女性。頭痛を伴わない回転性めまいで発症し,診察時には両側外転神経麻痺症状のみ認められた。CT でくも膜下出血,特にprepontine cistern に厚い血腫が認められ,MRA では脳底動脈瘤が認められた。破裂脳動脈瘤に対して,コイル塞栓術を施行した。術後,新たな神経学的異常所見は認められなかった。両側神経麻痺は発症から4か月後に完全回復が得られた。外転神経麻痺には幾つかの機序が挙げられている。動脈瘤の直接的な圧迫,脳浮腫や脳内出血による頭蓋内圧の亢進,外転神経核への栄養血管の攣縮などである。本症例ではprepontine cistern に限局した血腫による圧迫が影響して両側外転神経麻痺のみで発症したと考えられたA 54-year-old woman presented withdsudden vertigo without headache. Upon admission, neurological examination revealed isolated bilateral abducens nerve palsn. Computed tomography revealed subarachnoid haemorrhage, particularly aythick haematoma, in the prepontine cistern. Magnetic resonanceAangiography)showed a ruptured basilar artery aneurysm. Endovascular coil embolization was performed for this ruptured aneurysm. Postoperatively, no new neurological deficits were observed. Bilateral abducens nerve palsy recovered and disappeared 4 months after onset.sSeveral possible mechanisms can explain the occurrence of abducens nerve palsy, including the following: a direct mass effect of the aneurysmton the abducens nerve, increased intracranial pressure induced by brain swelling or parenchymal haemorrhage, and a vasospasm of thc pontine branch of the basilar artery supplying the abducens nuclei. In this case, we speculated that the isolated bilateral abducens nerve palsy was caused by compression of the local haematoma in the prepontine cistern secondary to a ruptured basilar artery aneurysm

    Observation of nuclear-spin Seebeck effect

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    Thermoelectric effects have been applied to power generators and temperature sensors that convert waste heat into electricity. The effects, however, have been limited to electrons to occur, and inevitably disappear at low temperatures due to electronic entropy quenching. Here, we report thermoelectric generation caused by nuclear spins in a solid: nuclear-spin Seebeck effect. The sample is a magnetically ordered material MnCO3 having a large nuclear spin (I = 5/2) of 55Mn nuclei and strong hyperfine coupling, with a Pt contact. In the system, we observe low-temperature thermoelectric signals down to 100 mK due to nuclear-spin excitation. Our theoretical calculation in which interfacial Korringa process is taken into consideration quantitatively reproduces the results. The nuclear thermoelectric effect demonstrated here offers a way for exploring thermoelectric science and technologies at ultralow temperaturesThis work was supported by JST ERATO “Spin Quantum Rectification Project” (JPMJER1402), JST CREST (JPMJCR20C1 and JPMJCR20T2), JSPS KAKENHI (JP19H05600, JP19K21031, JP20H02599, JP20K22476, and JP20K15160), MEXT [Innovative Area “Nano Spin Conversion Science” (JP26103005)], and Daikin Industries, Ltd. The work at UCLA was supported by the US Department of Energy, Office of Basic Energy Sciences under Award number DE-SC0012190. K.O. acknowledges support from GP-Spin at Tohoku University. R.R. acknowledges support from the European Commission through the project 734187-SPICOLOST (H2020-MSCA-RISE-2016), the European Union’s Horizon 2020 research and innovation program through the Marie Sklodowska-Curie Actions grant agreement SPEC number 894006 and the Spanish Ministry of Science (RYC 2019-026915-I)S

    Differential remodelling of peroxisome function underpins the environmental and metabolic adaptability of diplonemids and kinetoplastids

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    The remodelling of organelle function is increasingly appreciated as a central driver of eukaryotic biodiversity and evolution. Kinetoplastids including Trypanosoma and Leishmania have evolved specialized peroxisomes, called glycosomes. Glycosomes uniquely contain a glycolytic pathway as well as other enzymes, which underpin the physiological flexibility of these major human pathogens. The sister group of kinetoplastids are the diplonemids, which are among the most abundant eukaryotes in marine plankton. Here we demonstrate the compartmentalization of gluconeogenesis, or glycolysis in reverse, in the peroxisomes of the free-living marine diplonemid, Diplonema papillatum. Our results suggest that peroxisome modification was already under way in the common ancestor of kinetoplastids and diplonemids, and raise the possibility that the central importance of gluconeogenesis to carbon metabolism in the heterotrophic free-living ancestor may have been an important selective driver. Our data indicate that peroxisome modification is not confined to the kinetoplastid lineage, but has also been a factor in the success of their free-living euglenozoan relatives

    SUMOylation of Paraflagellar Rod Protein, PFR1, and Its Stage-Specific Localization in Trypanosoma cruzi

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    BACKGROUND: The flagellate protozoan parasite, Trypanosoma cruzi, is a causative agent of Chagas disease that is transmitted by reduviid bugs to humans. The parasite exists in multiple morphological forms in both vector and host, and cell differentiation in T. cruzi is tightly associated with stage-specific protein synthesis and degradation. However, the specific molecular mechanisms responsible for this coordinated cell differentiation are unclear. METHODOLOGY/PRINCIPAL FINDINGS: The SUMO conjugation system plays an important role in specific protein expression. In T. cruzi, a subset of SUMOlylated protein candidates and the nuclear localization of SUMO have been shown. Here, we examined the biological roles of SUMO in T. cruzi. Site-directed mutagenesis analysis of SUMO consensus motifs within T. cruzi SUMO using a bacterial SUMOylation system revealed that T. cruzi SUMO can polymerize. Indirect fluorescence analysis using T. cruzi SUMO-specific antibody showed the extra-nuclear localization of SUMO on the flagellum of epimastigote and metacyclic and bloodstream trypomastigote stages. In the short-flagellate intracellular amastigote, an extra-nuclear distribution of SUMO is associated with basement of the flagellum and becomes distributed along the flagellum as amastigote transforms into trypomastigote. We examined the flagellar target protein of SUMO and show that a paraflagellar rod protein, PFR1, is SUMOylated. CONCLUSIONS: These findings indicate that SUMOylation is associated with flagellar homeostasis throughout the parasite life cycle, which may play an important role in differentiation of T. cruzi

    Sulfate Activation in Mitosomes Plays an Important Role in the Proliferation of Entamoeba histolytica

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    Mitochondrion-related organelles, mitosomes and hydrogenosomes, are found in a phylogenetically broad range of organisms. Their components and functions are highly diverse. We have previously shown that mitosomes of the anaerobic/microaerophilic intestinal protozoan parasite Entamoeba histolytica have uniquely evolved and compartmentalized a sulfate activation pathway. Although this confined metabolic pathway is the major function in E. histolytica mitosomes, their physiological role remains unknown. In this study, we examined the phenotypes of the parasites in which genes involved in the mitosome functions were suppressed by gene silencing, and showed that sulfate activation in mitosomes is important for sulfolipid synthesis and cell proliferation. We also demonstrated that both Cpn60 and unusual mitochondrial ADP/ATP transporter (mitochondria carrier family, MCF) are important for the mitosome functions. Immunoelectron microscopy demonstrated that the enzymes involved in sulfate activation, Cpn60, and mitochondrial carrier family were differentially distributed within the electron dense, double membrane-bounded organelles. The importance and topology of the components in E. histolytica mitosomes reinforce the notion that they are not “rudimentary” or “residual” mitochondria, but represent a uniquely evolved crucial organelle in E. histolytica

    Comparison of hemolytic activity of the intermediate subunit of Entamoeba histolytica and Entamoeba dispar lectins

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    Galactose and N-acetyl-D-galactosamine-inhibitable lectin of Entamoeba histolytica has roles in pathogenicity and induction of protective immunity in rodent models of amoebiasis. Recently, the intermediate subunit of the lectin, Igl1, of E. histolytica has been shown to have hemolytic activity. However, the corresponding lectin is also expressed in a non-virulent species, Entamoeba dispar, and another subunit, Igl2, is expressed in the protozoa. Therefore, in this study, we compared the activities of Igl1 and Igl2 subunits from E. histolytica and E. dispar using various regions of recombinant Igl proteins expressed in Escherichia coli. The recombinant E. dispar Igl proteins had comparable hemolytic activities with those of E. histolytica Igl proteins. Furthermore, Igl1 gene-silenced E. histolytica trophozoites showed less hemolytic activity compared with vector-transfected trophozoites, indicating that the expression level of Igl1 protein influences the activity. These results suggest that the lower hemolytic activity in E. dispar compared with E. histolytica reflects the lower expression level of Igl1 in the E. dispar parasite

    Hetero-oligomer of dynamin-related proteins participates in the fission of highly divergent mitochondria from Entamoeba histolytica

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    Abstract Entamoeba histolytica is an anaerobic parasitic protist and possesses mitosomes, one of the most highly divergent mitochondrion-related organelles (MROs). Although unique metabolism and protein/metabolite transport machinery have been demonstrated in Entamoeba mitosomes, the mechanism of mitosomal fusion and fission remains to be elucidated. In this study, we demonstrate that two dynamin-related proteins (DRPs) are cooperatively involved in the fission of Entamoeba mitosomes. Expression of a dominant negative form of EhDrpA and EhDrpB, and alternatively, repression of gene expression of EhDrpA and EhDrpB genes, caused elongation of mitosomes, reflecting inhibition of mitosomal fission. Moreover, EhDrpA and EhDrpB formed an unprecedented hetero-oligomeric complex with an approximate 1:2 to 1:3 ratio, suggesting that the observed elongation of mitosomes is likely caused by the disruption and instability of the complex caused by an imbalance in the two DRPs. Altogether, this is the first report of a hetero-oligomeric DRP complex which participates in the fission of mitochondria and MROs

    Whole genome sequencing of Entamoeba nuttalli reveals mammalian host-related molecular signatures and a novel octapeptide-repeat surface protein.

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    The enteric protozoa Entamoeba histolytica is the causative agent of amebiasis, which is one of the most common parasitic diseases in developed and developing countries. Entamoeba nuttalli is the genetically closest species to E. histolytica in current phylogenetic analyses of Entamoeba species, and is prevalent in wild macaques. Therefore, E. nuttalli may be a key organism in which to investigate molecules required for infection of human or non-human primates. To explore the molecular signatures of host-parasite interactions, we conducted de novo assembly of the E. nuttalli genome, utilizing self-correction of PacBio long reads and polishing corrected reads using Illumina short reads, followed by comparative genomic analysis with two other mammalian and a reptilian Entamoeba species. The final draft assembly of E. nuttalli included 395 contigs with a total length of approximately 23 Mb, and 9,647 predicted genes, of which 6,940 were conserved with E. histolytica. In addition, we found an E. histolytica-specific repeat known as ERE2 in the E. nuttalli genome. GO-term enrichment analysis of mammalian host-related molecules indicated diversification of transmembrane proteins, including AIG1 family and BspA-like proteins that may be involved in the host-parasite interaction. Furthermore, we identified an E. nuttalli-specific protein that contained 42 repeats of an octapeptide ([G,E]KPTDTPS). This protein was shown to be localized on the cell surface using immunofluorescence. Since many repeat-containing proteins in parasites play important roles in interactions with host cells, this unique octapeptide repeat-containing protein may be involved in colonization of E. nuttalli in the intestine of macaques. Overall, our draft assembly provides a valuable resource for studying Entamoeba evolution and host-parasite selection
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