The Effect of Motor Imagery on Spinal Motor Neuron Excitability and Its Clinical Use in Physical Therapy

We investigated the influence of the imagined muscle contraction strengths on spinal motor neuron excitability in healthy volunteers. F‐wave was used for assessing spinal motor excitability. The F‐waves during motor imagery (MI) under 10, 30, 50, 70, and 100% maximal voluntary contractions (MVCs) were compared. Furthermore, we investigated changes of the F‐waves during motor imagery for 5 min. Motor imagery under 10, 30, 50, 70, and 100% maximal voluntary contractions can increase spinal motor neuron excitability. However, the imagined muscle contraction strengths were not involved in changes of spinal motor neuron excitability. Additionally, spinal motor neuron excitability after 5 min from onset of motor imagery returned to the rest level. Thus, in clinical use of motor imagery, slightly imagined muscle contraction strength is enough for facilitating spinal motor neuron excitability. Also, duration of motor imagery needs to be considered

Nephronectin plays critical roles in Sox2 expression and proliferation in dental epithelial stem cells via EGF-like repeat domains

Tooth development is initiated by epithelial-mesenchymal interactions via basement membrane (BM) and growth factors. In the present study, we found that nephronectin (Npnt), a component of the BM, is highly expressed in the developing tooth. Npnt localizes in the BM on the buccal side of the tooth germ and shows an expression pattern opposite that of the dental epithelial stem cell marker Sox2. To identify the roles of Npnt during tooth development, we performed knockdown and overexpression experiments using ex vivo organ and dental epithelial cell cultures. Our findings showed that loss of Npnt induced ectopic Sox2-positive cells and reduced tooth germ size. Over expression of Npnt showed increased proliferation, whereas the number of Sox2-positive cells was decreased in dental epithelial cells. Npnt contains 5 EGF-like repeat domains, as well as an RGD sequence and MAM domain. We found that the EGF-like repeats are critical for Sox2 expression and cell proliferation. Furthermore, Npnt activated the EGF receptor (EGFR) via the EGF-like repeat domains and induced the PI3K-Akt signaling pathway. Our results indicate that Npnt plays a critical scaffold role in dental epithelial stem cell differentiation and proliferation, and regulates Sox2 expression during tooth development

川崎医科大学におけるブース形式診療科別説明会の学内開催

川崎医科大学は,中核市の倉敷市内と政令指定都市の岡山市内に二つの附属病院を有している。両病院の卒後臨床研修プログラムは独立しているが,研修は両方の病院の診療科から選択することが可能である。平成27年7月,初めて川崎医科大学生を対象にした大学附属病院診療科の説明会をブース形式で学内開催した。研修プログラム説明会とは趣を異にし,各診療科の特徴や業務内容を広報することを目的とした。1年生から6年生までの学生が参加し,アンケート調査に回答した52名全員が将来の研修病院の選択に役に立ったと答え,うち27%は非常に役立ったと高い満足度を示した。また,研修医だけで計画した学生向けのミニシンポジウムも同時に開催し,来場した約70%の学生が参加し貴重な情報収集の場となった。次年度以降も改善を加えながら,学生が身近に附属病院スタッフや先輩研修医と交流できるイベントとして育てていきたい。Kawasaki Medical School has one hospital in Kurashiki City, a core city, and another in Okayama City, an ordinance-designated city. These hospitals have independent postgraduate clinical training programs. However, departments of both hospitals can be selected for training. In July 2015, a boothtype meeting regarding Kawasaki Medical School Hospital departments was held for Kawasaki Medical School students for the first time. The intent of the meeting differed from that of other training program meetings, and its goal was to provide information on the characteristics and tasks of each department. First- to sixth-year students participated in the meeting. All 52 students who responded to a questionnaire survey answered that the meeting was useful in helping them select a hospital for their future training, and 27% of them reported that the meeting was very useful and showed high levels of satisfaction. A mini symposium for students planned only by residents was also held at the same time. About 70% of visiting students participated in the symposium and were given a valuable opportunity to gather information. By making improvements, we will cultivate the meeting as an event in which students can have contact with hospital staff and junior residents from the next year

Phylogenetic relationships of three species within the family Heligmonellidae (Nematoda; Heligmosomoidea) from Japanese rodents and a lagomorph based on the sequences of ribosomal DNA internal transcribed spacers, ITS-1 and ITS-2

Nematodes of the family Heligmonellidae (Heligmosomoidea; Trichostrongylina) reside in the digestive tracts of rodents and lagomorphs. Although this family contains large numbers of genera and species, genetic information on the Heligmonellidae is very limited. We collected and isolated adult worms of three species in Japan that belong to the family Heligmonellidae, namely Heligmonoides speciosus (Konno, 1963) Durette-Desset, 1970 (Hs) from Apodemus argenteus, Orientostrongylus ezoensis Tada, 1975 (Oe) from Rattus norvegicus and Lagostrongylus leporis (Schulz, 1931) (Ll) from Pentalagus furnessi, and sequenced the entire internal transcribed spacer regions, ITS-1 and ITS-2 of ribosomal DNA. ITS-1 of Hs, Oe and Ll was 426, 468 and 449 bp in length, and had a G＋C content of about 41, 41 and 37 %, respectively. ITS-2 of Hs, Oe and Ll was 297, 319 and 276 bp in length and had a G＋C content of about 38, 40 and 28%, respectively. The data of Hs, Oe and Ll were compared with those of two other known species within the family Heligmonellidae, Calorinensis minutus (Dujardin, 1845) (Cm) and Nippostrogylus brasiliensis (Travassos, 1914) (Nb), and with those of two species of Heligmosomidae (Heligmosomoidea), Heligmosomoides polygyrus bakeri and Ohbayashinema erbaevae. Phylogenetic analysis placed Hs, Oe and Ll in the same clade with Cm and Nb, forming a Heligmonellidae branch in both ITS-1 and ITS-2, separate from the Heligmosomoidea branch. These results demonstrated that the ITS-1 and ITS-2 sequences are useful for differentiating the Heligmonellidae nematode species. This study is the first to describe the ITS-1 and ITS-2 sequences of Hs, Oe and Ll

Plakophilin-1, a Novel Wnt Signaling Regulator, Is Critical for Tooth Development and Ameloblast Differentiation

<div><p>Tooth morphogenesis is initiated by reciprocal interactions between the ectoderm and neural crest-derived mesenchyme, and the Wnt signaling pathway is involved in this process. We found that Plakophilin (PKP)1, which is associated with diseases such as ectodermal dysplasia/skin fragility syndrome, was highly expressed in teeth and skin, and was upregulated during tooth development. We hypothesized that PKP1 regulates Wnt signaling via its armadillo repeat domain in a manner similar to β-catenin. To determine its role in tooth development, we performed <i>Pkp1</i> knockdown experiments using ex vivo organ cultures and cell cultures. Loss of <i>Pkp1</i> reduced the size of tooth germs and inhibited dental epithelial cell proliferation, which was stimulated by Wnt3a. Furthermore, transfected PKP1-emerald green fluorescent protein was translocated from the plasma membrane to the nucleus upon stimulation with Wnt3a and LiCl, which required the PKP1 N terminus (amino acids 161 to 270). Localization of PKP1, which is known as an adhesion-related desmosome component, shifted to the plasma membrane during ameloblast differentiation. In addition, <i>Pkp1</i> knockdown disrupted the localization of Zona occludens 1 in tight junctions and inhibited ameloblast differentiation; the two proteins were shown to directly interact by immunoprecipitation. These results implicate the participation of PKP1 in early tooth morphogenesis as an effector of canonical Wnt signaling that controls ameloblast differentiation via regulation of the cell adhesion complex.</p></div

Wnt signaling induces translocation of PKP1 from membrane to nucleus.

<p>A, CLDE cells were transfected with PKP1-EmGFP, then treated with or without Wnt3a for 24 h. Nuclear translocation was detected by confocal microscopy. Nuclei were stained with DAPI. B, Enlarged image of PKP1-EmGFP nuclear translocation following stimulation with Wnt3a. C, Nuclear translocation ratio of CLDE cells treated with Wnt3a (*P <0.01). Error bars represent the mean ± S.D. D, CLDE cells were transfected with PKP1-EmGFP, then treated with 40 mM LiCl. Nuclear translocation was detected by confocal microscopy. E, Nuclear translocation ratios with different doses of LiCl in CLDE cells.</p

N terminus of PKP1 is required for nuclear translocation.

<p>A, Schematic representation of p120-catenin and PKP1-EmGFP constructs. PKP1-FL, full-length PKP1; PKP1-delN1, with deletion of N-terminal a.a. 1–160; PKP1-delN2, with deletion of N-terminal a.a. 1–270. All constructs contained the armadillo repeat domain. B, Nuclear translocation of PKP1-FL, -delN1, and -delN2 expressed in CLDE cells with or without LiCl treatment, as detected by confocal microscopy. C, Nuclear translocation ratios of CLDE cells transfected with PKP1-FL, -delN1, and -delN2 with or without LiCl treatment. D, Cell proliferation was determined after 72 h of culture by counting relative numbers of CLDE cells transfected with PKP1-FL and -delN2 with or without Wnt3a (*P <0.01). Error bars represent the mean ± S.D.</p

Pkp1 knockdown inhibits tooth germ growth and dental epithelial cell proliferation.

<p>A, CLDE cell proliferation 3 days after treatment with control or <i>Pkp1</i> siRNA, as determined by CCK-8 assay. B, BrdU incorporation by CLDE cells with or without <i>Pkp1</i> knockdown. The ratio was calculated as BrdU-positive cell number/DAPI-stained nuclei. C, Seven-day organ cultures of E13 tooth germs transfected with control or <i>Pkp1</i> siRNA. D, Relative tooth size plot (n = 12), with the average tooth germ size in the control siRNA group set at 1.0. E, qRT-PCR analysis of <i>Pkp1</i> expression in cultured tooth germ after normalization to <i>Gapdh</i> mRNA expression. F, CLDE cell proliferation in the presence of Wnt3a was evaluated using a CCK-8 assay after transfection with control or <i>Pkp1</i> siRNA. G, TCF/LEF promoter activity after stimulation with Wnt3a was examined using a luciferase assay after transfection with control or <i>Pkp1</i> siRNA. *P <0.01, Error bars represent the mean ± S.D.</p