86 research outputs found
Lmtk3-KO Mice Display a Range of Behavioral Abnormalities and Have an Impairment in GluA1 Trafficking
Accumulating evidence suggests that glutamatergic signaling and synaptic plasticity underlie one of a number of ways psychiatric disorders appear. The present study reveals a possible mechanism by which this occurs, through highlighting the importance of LMTK3, in the brain. Behavioral analysis of Lmtk3-KO mice revealed a number of abnormalities that have been linked to psychiatric disease such as hyper-sociability, PPI deficits and cognitive dysfunction. Treatment with clozapine suppressed these behavioral changes in Lmtk3-KO mice. As synaptic dysfunction is implicated in human psychiatric disease, we analyzed the LTP of Lmtk3-KO mice and found that induction is severely impaired. Further investigation revealed abnormalities in GluA1 trafficking after AMPA stimulation in Lmtk3-KO neurons, along with a reduction in GluA1 expression in the post-synaptic density. Therefore, we hypothesize that LMTK3 is an important factor involved in the trafficking of GluA1 during LTP, and that disruption of this pathway contributes to the appearance of behavior associated with human psychiatric disease in mice
Potency of Fish Collagen as a Scaffold for Regenerative Medicine
Cells, growth factors, and scaffold are the crucial factors for tissue engineering. Recently, scaffolds consisting of natural polymers, such as collagen and gelatin, bioabsorbable synthetic polymers, such as polylactic acid and polyglycolic acid, and inorganic materials, such as hydroxyapatite, as well as composite materials have been rapidly developed. In particular, collagen is the most promising material for tissue engineering due to its biocompatibility and biodegradability. Collagen contains specific cell adhesion domains, including the arginine-glycine-aspartic acid (RGD) motif. After the integrin receptor on the cell surface binds to the RGD motif on the collagen molecule, cell adhesion is actively induced. This interaction contributes to the promotion of cell growth and differentiation and the regulation of various cell functions. However, it is difficult to use a pure collagen scaffold as a tissue engineering material due to its low mechanical strength. In order to make up for this disadvantage, collagen scaffolds are often modified using a cross-linker, such as gamma irradiation and carbodiimide. Taking into account the possibility of zoonosis, a variety of recent reports have been documented using fish collagen scaffolds. We herein review the potency of fish collagen scaffolds as well as associated problems to be addressed for use in regenerative medicine
Ceramide structures involved in the recognition of Siglec-7
To analyze the binding specificity of a sialic acid–recognizing lectin, sialic acid-binding Ig-like lectin 7 (SIGLEC7), to disialyl gangliosides (GD3s), here we established GD3-expressing cells by introducing GD3 synthase (GD3S or ST8SIA1) cDNA into a colon cancer cell line, DLD-1, that expresses no ligands for the recombinant protein SIGLEC7-Fc. SIGLEC7-Fc did not recognize newly-expressed GD3 on DLD-1 cells, even though GD3 was highly expressed, as detected by an anti-GD3 antibody. Because milk-derived GD3 could be recognized by this fusion protein when incorporated onto the surface of DLD-1 cells, we compared the ceramides in DLD-1–generated and milk-derived GD3s to identify the SIGLEC7-specific GD3 structures on the cell membrane, revealing that SIGLEC7 recognizes only GD3-containing regular ceramides but not phytoceramides. This was confirmed by knockdown/knockout of the sphingolipid delta(4)-desaturase/C4-monooxygenase (DES2) gene, involved in phytoceramide synthesis, disclosing that DES2 inhibition confers SIGLEC7 binding. Furthermore, knocking out fatty acid 2-hydroxylase also resulted in the emergence of SIGLEC7 binding to the cell surface. To analyze the effects of binding between SIGLEC7 and various GD3 species on natural killer function, we investigated cytotoxicity of peripheral blood mononuclear cells from healthy donors toward GD3S-transfected DLD-1 (DLD-1–GD3S) cells and DLD-1–GD3S cells with modified ceramides. We found that cytotoxicity is suppressed in DLD-1–GD3S cells with dehydroxylated GD3s. These results indicate that the ceramide structures in glycosphingolipids affect SIGLEC7 binding and distribution on the cell surface and influence cell sensitivity to killing by SIGLEC7-expressing effector cells
The Characterization of Fish (Tilapia) Collagen Sponge as a Biomaterial
For scaffold manufacturing, the utility of bioactive natural organic materials derived from marine products is useful and indispensable as an alternative to bovine collagen. The weakest feature of fish collagen for scaffold application is its low degeneration temperature (Td), indicating poor stability of fish collagen in mammals in vivo. We have focused on the tropical fish tilapia as a candidate for generating a clinical scaffold. The aim of this study was to confirm the Td of tilapia type I atelocollagen (TAC) for biomedical application. Furthermore, the physical and structural properties were investigated and evaluated as a scaffold on a sponge form. Different concentrations {0.5%, 1.0%, and 2.0% (v/v)} of TAC solution were analyzed. Differential scanning calorimetry showed that the Td of TAC was 35-36°C. The scanning electron microscopy results indicated that the pore size (90-160 m) of TAC sponges is acceptable for cell proliferation. The tensile strength of porous sponges was in the range of 0.01-0.07 MPa. These findings indicate that the TAC sponge prepared from tilapia is one of candidates as a scaffold. The 1.0% (v/v) concentration of TAC solution is especially recommended to be advantageous for preparing and handling the solution and for sponge formation
Fabrication and Characteristics of Chitosan Sponge as a Tissue Engineering Scaffold
Cells, growth factors, and scaffolds are the three main factors required to create a tissue-engineered construct. After the appearance of bovine spongiform encephalopathy (BSE), considerable attention has therefore been focused on nonbovine materials. In this study, we examined the properties of a chitosan porous scaffold. A porous chitosan sponge was prepared by the controlled freezing and lyophilization of different concentrations of chitosan solutions. The materials were examined by scanning electron microscopy, and the porosity, tensile strength, and basic fibroblast growth factor (bFGF) release profiles from chitosan sponge were examined in vitro. The morphology of the chitosan scaffolds presented a typical microporous structure, with the pore size ranging from 50 to 200 m. The porosity of chitosan scaffolds with different concentrations was approximately 75-85%. A decreasing tendency for porosity was observed as the concentration of the chitosan increased. The relationship between the tensile properties and chitosan concentration indicated that the ultimate tensile strength for the sponge increased with a higher concentration. The in vitro bFGF release study showed that the higher the concentration of chitosan solution became, the longer the releasing time of the bFGF from the chitosan sponge was
Biological Safety of Fish (Tilapia) Collagen
Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing site-specific cellular regulation. This study was conducted to confirm the safety of fish (tilapia) atelocollagen for use in clinical application. We performed in vitro and in vivo biological studies of medical materials to investigate the safety of fish collagen. The extract of fish collagen gel was examined to clarify its sterility. All present sterility tests concerning bacteria and viruses (including endotoxin) yielded negative results, and all evaluations of cell toxicity, sensitization, chromosomal aberrations, intracutaneous reactions, acute systemic toxicity, pyrogenic reactions, and hemolysis were negative according to the criteria of the ISO and the Ministry of Health, Labour and Welfare of Japan. The present study demonstrated that atelocollagen prepared from tilapia is a promising biomaterial for use as a scaffold in regenerative medicine
Organized and Sustainable Education Program for Drug Abuse Prevention by Yogo-teachers
学校における喫煙・飲酒・薬物乱用防止教育の充実には,問題行動が顕在化する中学校期だけでなく小学校期
における指導の推進が重要であり,系統的な指導計画を立て,指導者や時間の確保,教材作成などに組織的に取
組み,継続可能なプログラム開発を行う必要がある。そこで,地区内12 校の養護教諭が協働して,発達段階に応
じた系統的・組織的かつ継続可能な地区共通の指導計画を開発し,各校の教育課程・年間計画に位置付けた実践
研究を行った。その結果,指導計画の実施状況は,小学校11 校中,学級活動10 校,ミニ保健指導10 校,長期
休業前指導6 校,広報活動9 校となり,特別支援学校1 校では広報活動のみを行うことができた。小学校におけ
る喫煙・飲酒・薬物乱用防止教育の推進には,学校保健活動の中核的役割を担う養護教諭が専門性を活かし協働
して,系統的な指導計画を各校の教育課程に位置付け組織的で継続可能なプログラムとする取組が有効であった
Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension
OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo
Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab
The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension
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