25 research outputs found

    Novel Autologous Therapy for Long-Gap Peripheral Nerve Injury Using Human Sk-SCs

    Get PDF
    Losses in vital functions of the somatic motor and sensory nervous system are induced by severe long-gap peripheral nerve transection injury. In such cases, autologous nerve grafts are the gold standard treatment, despite the unavoidable sacrifice of other healthy functions, whereas the prognosis is not always favorable. Here, we use human skeletal muscle-derived stem cells (Sk-SCs) to reconstitute the function after long nerve-gap injury. Muscles samples were obtained from the amputated legs from 9 patients following unforeseen accidents. The Sk-SCs were isolated using conditioned collagenase solution, and sorted as CD34+/45- (Sk-34) and CD34-/45-/29+ (Sk-DN/29+) cells. Cells were separately cultured/expanded under optimal conditions for 2 weeks, then injected into the athymic nude mice sciatic nerve long-gap model (7-mm) bridging an acellular conduit. After 8-12 weeks, active cell engraftment was observed only in the Sk-34 cell transplanted group, showing preferential differentiation into Schwann cells and perineurial/endoneurial cells, as well as formation of the myelin sheath and perineurium/endoneurium surrounding regenerated axons, resulted in 87% of numerical recovery. Differentiation into vascular cell lineage (pericyte and endothelial cells) were also observed. A significant tetanic tension recovery (over 90%) of downstream muscles following electrical stimulation of the sciatic nerve (at upper portion of the gap) was also achieved. In contrast, Sk-DN/29+ cells were completely eliminated during the first 4 weeks, but relatively higher numerical (83% vs. 41% in axon) and functional (80% vs. 60% in tetanus) recovery than control were observed. Noteworthy, significant increase in the formation of vascular networks in the conduit during the early stage (first 2 weeks) of recovery was observed in both groups with the expression of key factors (mRNA and protein levels), suggesting the paracrine effects to angiogenesis. These results suggested that the human Sk-SCs may be a practical source for autologous stem cell therapy following severe peripheral nerve injury

    Chemoenzymatic Synthesis and Chemical Recycling of Poly(ester-urethane)s

    Get PDF
    Novel poly(ester-urethane)s were prepared by a synthetic route using a lipase that avoids the use of hazardous diisocyanate. The urethane linkage was formed by the reaction of phenyl carbonate with amino acids and amino alcohols that produced urethane-containing diacids and hydroxy acids, respectively. The urethane diacid underwent polymerization with polyethylene glycol and α,ω-alkanediols and also the urethane-containing hydroxy acid monomer was polymerized by the lipase to produce high-molecular-weight poly(ester-urethane)s. The periodic introduction of ester linkages into the polyurethane chain by the lipase-catalyzed polymerization afforded chemically recyclable points. They were readily depolymerized in the presence of lipase into cyclic oligomers, which were readily repolymerized in the presence of the same enzyme. Due to the symmetrical structure of the polymers, poly(ester-urethane)s synthesized in this study showed higher Tm, Young’s modulus and tensile strength values

    Implementasi manajemen sarana dan prasarana dalam meningkatkan mutu pendidikan pada madrasah tsanawiyah negeri (MTSN) Rantauprapat Kabupaten Labuhanbatu

    Get PDF
    Penelitian ini bertujuan untuk mengetahui perencanaan, pengorganisasian, pelaksanaan, pengawasan manajemen sarana dan prasarana dalam meningkatkan mutu pendidikan pada Madrasah Tsanawiyah Negeri (MTsN) Rantauprapat Kabupaten Labuhanbatu. Penelitian ini dilakukan dengan menggunakan pendekatan kualitatif, Teknik pengumpulan data dalam penelitian ini menggunakan observasi, wawancara dan dokumen. Data yang didapat kemudian dianalisis dengan menggunakan analisis data kualitatif yang terdiri dari: (a).reduksi data, (b).penyajian data, dan (c) penarikan kesimpulan. Temuan penelitian: (1) perencanaan manajemen sarana dan prasarana di Madrasah Tsanawiyah Negeri (MTsN) Rantauprapat Kabupaten Labuhanbatu terlebih dahulu dilakukan analisis kebutuhan riil baik yang menyangkut kebutuhan administrasi maupun pendukung kegiatan proses pembelajaran, seperti ruang kelas, moubilair, dan lain sebagainya. Yang melibatkan: Kepala Madrasah, KTU, bendahara, PKM, dan bahkan utusan dari komite sekolah. (2).Pengorganisasian manajemen sarana dan prasarana pada Madrasah Tsanawiyah Negeri (MTsN) Rantauprapat Kabupaten Labuhanbatu dilakukan berdasarkan rumpun (kelompok) dari setiap jenis sarana itu sendiri, misalnya: bangunan fisik, moubilair, ATK, lingkungan, dan lain sebagainya yang kesemuanya itu di arsiparis berdasarkan ketentuan yang berlaku. (3) Pelaksanaan manajemen sarana dan prasarana di Madrasah Tsanawiyah Negeri (MTsN) Rantauprapat Kabupaten Labuhanbatu berjalan baik dan lancar. Pelaksanaannya masing-masing pihak bekerja sesuai job/pekerjaan masing-masing dan sesuai kepentingannya, sehingga sistem kerja tidak ada tumpang tindih antara satu sama lain. Dan pertanggung jawabannya langsung kepada Kepala madrasah MTsN Rantauprapat walaupun tetap di bawah koordinasi PKM sarana dan prasarana. (4).Pengawasan manajemen sarana dan prasarana pada Madrasah Tsanawiyah Negeri (MTsN) Rantauprapat Kabupaten Labuhanbatu dilakukan dengan cara: a) Pengawasan rutin setiap harinya yang dilakukan oleh PKM sarana jika menyangkut persoalan sarana pendukung pembelajaran, sedangkan yang menyangkut administrasi dilakukan oleh KTU. b) Secara berkala yakni setiap 6 (enam) bulan sekali diadakan rapat evaluasi tentang keadaan sarana dan prasarana. (5) Terkait dengan evaluasi diketahui bahwa sarana dan prasarana di Madrasah Tsanawiyah Negeri (MTsN) Rantauprapat Kabupaten Labuhanbatu sudah terpenuhi dan sesuai dengan standar pendidikan nasional.

    Fuel Regression Characteristics of Axial-Injection End-Burning Hybrid Rocket Using Nitrous Oxide

    Get PDF
    This is an investigation of fuel regression characteristics in an axial-injection end-burning hybrid rocket using nitrous oxide. Experiments were conducted using 38 mm cylindrical fuel grains with an array of 0.8 mm ports made from curable resin. Previous studies of end-burning hybrid rockets used gaseous oxygen as oxidizer. Nitrous oxide may be more suitable than gaseous oxygen for use in space-based missions because of the weight savings associated with the oxidizer storage vessels, supply system, and motor mass. In this study, two types of nozzle closures were employed to increase the initial chamber pressure and promote the formation of stabilized combustion in multiport fuels. The results of 12 firing tests showed that the regression rates when using nitrous oxide as the oxidizer were as high as that from previous research (0.61–4.5 mm/s at 0.25–0.75 MPa) using gaseous oxygen as the oxidizer. These high regression rates were nearly five times higher than that of experiments using single-port fuels. It is clear from a visualization experiment that fuel flakes break off and travel downstream in solid form during firing, which could cause the fuel regression rate of multiport fuels to be higher than that of single-port fuels

    Voluntary Exercise Positively Affects the Recovery of Long-Nerve Gap Injury Following Tube-Bridging with Human Skeletal Muscle-Derived Stem Cell Transplantation

    No full text
    The therapeutic effects of voluntary exercise on the recovery of long-gap nerve injury following the bridging of an acellular conduit filled with human skeletal muscle-derived stem cells (Sk-SCs) have been described. Human Sk-SCs were sorted as CD34+/45− (Sk-34) cells, then cultured/expanded under optimal conditions for 2 weeks. Surgery to generate a long-gap sciatic nerve injury was performed in athymic nude mice, after which the mice were divided into exercise (E) and non-exercise (NE) groups. The mice were housed in standard individual cages, and voluntary exercise wheels were introduced to the cages of the E group one week after surgery. After 8 weeks, the human Sk-34 cells were actively engrafted, and showed differentiation into Schwann cells and perineurial cells, in both groups. The recovery in the number of axons and myelin in the conduit and downstream tibial nerve branches, and the lower hindlimb muscle mass and their tension output, was consistently higher by 15–25% in the E group. Moreover, a significantly higher innervation ratio of muscle spindles, reduced pathological muscle fiber area, and acceleration of blood vessel formation in the conduit were each observed in the E group. These results showed that the combined therapy of tube-bridging, Sk-34 cell transplantation, and voluntary exercise is a potentially practical approach for recovery following long-gap nerve injury

    A Long-Gap Peripheral Nerve Injury Therapy Using Human Skeletal Muscle-Derived Stem Cells (Sk-SCs): An Achievement of Significant Morphological, Numerical and Functional Recovery.

    No full text
    Losses in vital functions of the somatic motor and sensory nervous system are induced by severe long-gap peripheral nerve transection injury. In such cases, autologous nerve grafts are the gold standard treatment, despite the unavoidable sacrifice of other healthy functions, whereas the prognosis is not always favorable. Here, we use human skeletal muscle-derived stem cells (Sk-SCs) to reconstitute the function after long nerve-gap injury. Muscles samples were obtained from the amputated legs from 9 patients following unforeseen accidents. The Sk-SCs were isolated using conditioned collagenase solution, and sorted as CD34+/45- (Sk-34) and CD34-/45-/29+ (Sk-DN/29+) cells. Cells were separately cultured/expanded under optimal conditions for 2 weeks, then injected into the athymic nude mice sciatic nerve long-gap model (7-mm) bridging an acellular conduit. After 8-12 weeks, active cell engraftment was observed only in the Sk-34 cell transplanted group, showing preferential differentiation into Schwann cells and perineurial/endoneurial cells, as well as formation of the myelin sheath and perineurium/endoneurium surrounding regenerated axons, resulted in 87% of numerical recovery. Differentiation into vascular cell lineage (pericyte and endothelial cells) were also observed. A significant tetanic tension recovery (over 90%) of downstream muscles following electrical stimulation of the sciatic nerve (at upper portion of the gap) was also achieved. In contrast, Sk-DN/29+ cells were completely eliminated during the first 4 weeks, but relatively higher numerical (83% vs. 41% in axon) and functional (80% vs. 60% in tetanus) recovery than control were observed. Noteworthy, significant increase in the formation of vascular networks in the conduit during the early stage (first 2 weeks) of recovery was observed in both groups with the expression of key factors (mRNA and protein levels), suggesting the paracrine effects to angiogenesis. These results suggested that the human Sk-SCs may be a practical source for autologous stem cell therapy following severe peripheral nerve injury
    corecore