46 research outputs found

    Human Very Small Embryonic-Like Cells Generate Skeletal Structures, In Vivo

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    Human very small embryonic-like (hVSEL) cells are a resident population of multipotent stem cells in the bone marrow involved in the turnover and regeneration of tissues. The levels of VSEL cells in blood are greatly increased in response to injury, and they have been shown to repair injured tissues. Adult hVSEL cells, SSEA-4+/CD133+/CXCR4+/Lin?/CD45?, express the pluripotency markers (Oct-4 and Nanog) and may be able to differentiate into cells from all 3 germ lineages. hVSEL cells isolated from blood by apheresis following granulocyte?colony-stimulating factor mobilization were fractionated and enriched by elutriation and fluorescence activated cell sorting. Collagen sponge scaffolds containing 2,000?30,000 hVSEL cells were implanted into cranial defects generated in SCID mice. Analysis by microcomputed tomography showed that a cell population containing VSEL cells produced mineralized tissue within the cranial defects compared with controls at 3 months. Histologic studies showed significant bone formation and cellular organization within the defects compared with cellular or scaffold controls alone. Antibodies to human leukocyte antigens demonstrated that the newly generated tissues were of human origin. Moreover, human osteocalcin was identified circulating in the peripheral blood. There was evidence that some level of hVSEL cells migrated away from the defect site, using quantitative real-time polymerase chain reaction to detect for human-specific Alu sequences. This study demonstrates that hVSEL cells are able to generate human bone tissue in a mouse model of skeletal repair. These studies lay the foundation for future cell-based regenerative therapies for osseous and connective tissue disorders, including trauma and degenerative conditions, such as osteoporosis, fracture repair, and neoplastic repair.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140198/1/scd.2012.0327.pd

    Human and Murine Very Small Embryonic-Like Cells Represent Multipotent Tissue Progenitors, In Vitro and In Vivo

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    The purpose of this study was to determine the lineage progression of human and murine very small embryonic-like (HuVSEL or MuVSEL) cells in vitro and in vivo. In vitro, HuVSEL and MuVSEL cells differentiated into cells of all three embryonic germ layers. HuVSEL cells produced robust mineralized tissue of human origin compared with controls in calvarial defects. Immunohistochemistry demonstrated that the HuVSEL cells gave rise to neurons, adipocytes, chondrocytes, and osteoblasts within the calvarial defects. MuVSEL cells were also able to differentiate into similar lineages. First round serial transplants of MuVSEL cells into irradiated osseous sites demonstrated that ?60% of the cells maintained their VSEL cell phenotype while other cells differentiated into multiple tissues at 3 months. Secondary transplants did not identify donor VSEL cells, suggesting limited self renewal but did demonstrate VSEL cell derivatives in situ for up to 1 year. At no point were teratomas identified. These studies show that VSEL cells produce multiple cellular structures in vivo and in vitro and lay the foundation for future cell-based regenerative therapies for osseous, neural, and connective tissue disorders. Key Points HuVSEL and MuVSEL cells are capable of differentiating into multiple germline derivatives in vitro and in vivo. MuVSEL cells have limited capacity for self-renewal and neither HuVSEL nor MuVSEL cells formed tumors in immunodeficient animals.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140202/1/scd.2013.0362.pd

    Review article: Use of ultrasound in the developing world

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    As portability and durability improve, bedside, clinician-performed ultrasound is seeing increasing use in rural, underdeveloped parts of the world. Physicians, nurses and medical officers have demonstrated the ability to perform and interpret a large variety of ultrasound exams, and a growing body of literature supports the use of point-of-care ultrasound in developing nations. We review, by region, the existing literature in support of ultrasound use in the developing world and training guidelines currently in use, and highlight indications for emergency ultrasound in the developing world. We suggest future directions for bedside ultrasound use and research to improve diagnostic capacity and patient care in the most remote areas of the globe

    Introduction: Special Issue on "Gender, Sexuality and Political Economy"

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    More effective hydraulic fracturing in secondary, in-fill developments, Permian Basin, using bottomhole pressure\ua0and\ua0in‐situ\ua0stress\ua0profiling\ua0techniques

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    Hydraulic fracturing in the secondary recovery units in the Permian Basin of west Texas is often complicated by a number of factors. Generally, there exists a lack of historical data or information required to effectively design the desired treatment. Therefore, treatments in these fields have often been "cook-booked" and given less engineering attention due to their smaller size and scope. Many times the process is further complicated by the iterative nature required in effective treatment modeling (i.e., historical review, candidate selection, pre-job design, pre-job diagnostics, on-site or post-job modeling, and post-job diagnostics). In this paper, we will outline the steps required to improve these processes without expending excessive resources. Then, we will discuss steps where streamlining the process is warranted without compromising the end result, Finally, we will document and present several cases illustrating effective use of these technologies to obtain more accurate stress profiles and improved fracture treatments in secondary, in-fill development projects

    Variation in invertebrate-bryophyte community structure at different spatial scales along altitudinal gradients

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    Aim: This study assessed changes in diversity and assemblage composition in bryophytes and their associated invertebrates along altitudinal gradients in Australia and New Zealand. The importance of altitude in shaping these communities and for the diversity of both invertebrates and bryophytes was examined at different spatial scales, including local, altitudinal, regional and biogeographical. Location: Samples were taken from four Australasian mountain ranges between 42° and 43°S: Mt Field and Mt Rufus, Tasmania, Australia, and Otira Valley and Seaward Kaikoura Mountains, South Island, New Zealand. Methods: On both Tasmanian mountains, five altitudes were assessed (250, 500, 750, 1000 and 1250 m). At each location (mountain/altitude combination) two sites were chosen and six samples were taken. Six altitudes were assessed on New Zealand mountains (Otira: 250, 500,750, 1000, 1250 and 1500 m; Kaikoura: 1130, 1225, 1325, 1425, 1525 and 2000 m). Bryophyte substrate was collected, and all samples were stored in 70% ethanol. Invertebrates were extracted from bryophytes using kerosene-phase separation and all invertebrates were identified to family. At each location in Tasmania, all bryophyte species within six 25-cm2 grids per site were collected and identified to species. Bryophytes from New Zealand were identified to species from the invertebrate sample substrate because of sampling constraints. Results: Altitude did have a significant effect on diversity, however, no general trend was found along the altitudinal gradient on the four mountains. There were distinct differences in diversity between biogeographical regions, mountains, altitudes and sites. In Tasmania, Mt Field had the highest diversity in invertebrates and bryophytes at 750 m. In contrast, Mt Rufus had consistent low invertebrate and bryophyte diversity along the entire altitudinal gradient. There were also distinctive differences between locations in the composition of invertebrate and bryophyte communities in Tasmania. Along the two altitudinal gradients in New Zealand, Otira had highest diversity for both invertebrates and bryophytes at low altitudes, whereas Kaikoura had highest invertebrate and lowest bryophyte diversity at the highest altitude. Main conclusions: There was an effect of altitude, however, there were no consistent changes in diversity or composition on the four different mountains. There was considerable local and regional variation, and, despite a strong sampling design, no underlying altitudinal trends were detectable. This study demonstrates the importance of examining a range of spatial scales if patterns in community structure along altitudinal gradients are to be studied. The implications of this study are discussed with reference to survey design, taxonomic resolution, climate change and conservation of habitat.16 page(s

    Variation in invertebrate-bryophyte community structure at different spatial scales along altitudinal gradients

    No full text
    Aim: This study assessed changes in diversity and assemblage composition in bryophytes and their associated invertebrates along altitudinal gradients in Australia and New Zealand. The importance of altitude in shaping these communities and for the diversity of both invertebrates and bryophytes was examined at different spatial scales, including local, altitudinal, regional and biogeographical. Location: Samples were taken from four Australasian mountain ranges between 42°and 46°S: Mt Field and Mt Rufus, Tasmania, Australia, and Otira Valley and Seaward Kaikoura Mountains, South Island, New Zealand. Methods: On both Tasmanian mountains, five altitudes were assessed (250, 500, 750,1000 and 1250 m). At each location (mountain/altitude combination) two sites were chosen and six samples were taken. Six altitudes were assessed on New Zealand mountains (Otira: 250, 500, 750, 1000, 1250 and 1500 m; Kaikoura: 1130, 1225, 1325,1425, 1525 and 2000 m). Bryophyte substrate was collected, and all samples were stored in 70% ethanol. Invertebrates were extracted from bryophytes using kerosene-phase separation and all invertebrates were identified to family. At each location in Tasmania, all bryophyte species within six 25-cmÂČ grids per site were collected and identified to species. Bryophytes from New Zealand were identified to species from the invertebrate sample substrate because of sampling constraints. Results: Altitude did have a significant effect on diversity, however, no general trend was found along the altitudinal gradient on the four mountains. There were distinct differences in diversity between biogeographical regions, mountains, altitudes and sites. In Tasmania, Mt Field had the highest diversity in invertebrates and bryophytes at750 m. In contrast, Mt Rufus had consistent low invertebrate and bryophyte diversity along the entire altitudinal gradient. There were also distinctive differences between locations in the composition of invertebrate and bryophyte communities in Tasmania. Along the two altitudinal gradients in New Zealand, Otira had highest diversity for both invertebrates and bryophytes at low altitudes, whereas Kaikoura had highest invertebrate and lowest bryophyte diversity at the highest altitude. Main conclusions: There was an effect of altitude, however, there were no consistent changes in diversity or composition on the four different mountains. There was considerable local and regional variation, and, despite a strong sampling design, no underlying altitudinal trends were detectable. This study demonstrates the importance of examining a range of spatial scales if patterns in community structure along altitudinal gradients are to be studied. The implications of this study are discussed with reference to survey design, taxonomic resolution, climate change and conservation of habitat
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