128 research outputs found

    Mechanical loading of stem cells for improvement of transplantation outcome in a model of acute myocardial infarction: The role of loading history

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    Stem cell therapy for tissue repair is a rapidly evolving field and the factors that dictate the physiological responsiveness of stem cells remain under intense investigation. In this study we hypothesized that the mechanical loading history of muscle-derived stem cells (MDSCs) would significantly impact MDSC survival, host tissue angiogenesis, and myocardial function after MDSC transplantation into acutely infarcted myocardium. Mice with acute myocardial infarction by permanent left coronary artery ligation were injected with either nonstimulated (NS) or mechanically stimulated (MS) MDSCs. Mechanical stimulation consisted of stretching the cells with equibiaxial stretch with a magnitude of 10% and frequency of 0.5Hz. MS cell-transplanted hearts showed improved cardiac contractility, increased numbers of host CD31+ cells, and decreased fibrosis, in the peri-infarct region, compared to the hearts treated with NS MDSCs. MS MDSCs displayed higher vascular endothelial growth factor expression than NS cells in vitro. These findings highlight an important role for cyclic mechanical loading preconditioning of donor MDSCs in optimizing MDSC transplantation for myocardial repair. © 2012, Mary Ann Liebert, Inc

    Social Wasps in Exotic Forest Planting and Atlantic Rainforest in the Neotropical Region

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    Social wasps play an important role in communities, whether in natural or agricultural ecosystems, performing pollination and/or predation on other organisms, especially caterpillars, which reveals their potential for biological control. We register species of predatory wasps found in a eucalypt reforested area compared with a native rainforest. Five species of social wasps were found: Agelaia myrmecophila (Ducke), Mischocyttarus punctatus (Ducke), Polistes carnifex (Fabricius), Polybia liliacea (Fabricius), and Polybia striata (Fabricius), with higher numbers in the eucalypt monoculture than in the Atlantic rainforest, suggesting no negative impact of the monoculture on the population of that natural enemies

    Aging Skin: Nourishing from Out-In. Lessons from Wound Healing

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    Skin lesion therapy, peculiarly in the elderly, cannot be isolated from understanding that the skin is an important organ consisting of different tissues. Furthermore, dermis health is fundamental for epidermis integrity, and so adequate nourishment is mandatory in maintaining skin integrity. The dermis nourishes the epidermis, and a healthy epidermis protects the dermis from the environment, so nourishing the dermis through the epidermal barrier is a technical problem yet to be resolved. This is also a consequence of the laws and regulations restricting cosmetics, which cannot have properties that pass the epidermal layer. There is higher investment in cosmetics than in the pharmaceutical industry dealing with skin therapies, because the costs of drug registration are enormous and the field is unprofitable. Still, wound healing may be seen as an opportunity to “feed” the dermis directly. It could also verify whether providing substrates could promote efficient healing and test optimal skin integrity maintenance, if not skin rejuvenation, in an ever aging population

    Breaking barriers: female and Hispanic undergraduate students experience gains in self-confidence and tolerance for obstacles during a sustainability-centered internship program in the USA

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    Previous research has shown that female and Hispanic students who are underrepresented in science, technology, engineering and mathematics (STEM) face more educational barriers than their non-Hispanic, male peers. However, little research has been conducted on the effects of intersectional identities in the STEM space. In an effort to bridge the gap in underrepresented students\u27 experience, the PSEG Institute for Sustainability Studies organizes a paid, interdisciplinary, team-based, experiential learning and internship program called the Green Teams that occurs during 10 weeks of the summer. The Green Teams Program strives to provide undergraduate students from all backgrounds–academically, economically, and demographically–an opportunity to develop their abilities in STEM fields and prepare them to enter the professional world. Based upon a survey given post-internship, self-reported learning gains for all students were analyzed to determine if the program had a significantly greater impact on students who are from groups traditionally underrepresented in STEM in their STEM-related learning gains and their confidence in STEM disciplines. Through t-tests, a Principal Component Analysis (PCA), and a 2-way factorial Analysis of Variance (ANOVA), Hispanic and female participants were found to report significantly higher learning gains than their counterparts in multiple STEM areas from increased tolerance for obstacles to gains in self confidence. The results of the study suggest Hispanic and female students benefit from paid work experiences in STEM with diverse peers and intentional, supportive mentoring. This research on the Green Teams Program provides insight into how this approach positively impacts STEM education of individuals from traditionally underrepresented groups in STEM. The findings may help to further guide the development of the Green Teams Program and the adoption of paid, interdisciplinary, team-based, experiential learning and internship experiences in additional academic STEM settings

    Domesticação das paisagens amazônicas

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    RESUMO Na imaginação popular a Amazônia é um bioma natural, o que nega a existência e agência dos Povos Indígenas que chegaram há pelo menos 13 mil anos. Este ensaio demonstra que a Amazônia é uma teia de interações socioecológicas, como resultado da domesticação de paisagens e de populações de espécies. As práticas envolvidas na domesticação de paisagens são simples, embora baseadas em conhecimento profundo, e respeitam não humanos. Os Povos Indígenas combinam horticultura e domesticação de paisagens, bem como sedentarismo e mobilidade. Os Mebêngôkre (Kayapó) e Baniwa praticam mais horticultura, enquanto os Nukak e Zo’é são mais móveis, e a domesticação de suas paisagens reflete essas diferenças. Florestas domesticadas produzem alimentos tanto quanto roças e capoeiras, todas levam a manutenção ou regeneração da floresta. Essas práticas sugerem que as sociedades nacional e global podem aprender a produzir alimentos com a floresta em pé, o que contribuiria a mitigar os efeitos do Antropoceno

    Locally delivered antistaphylococcal lysin exebacase or CF-296 is active in methicillin-resistant <i>Staphylococcus aureus</i> implant-associated osteomyelitis

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    Introduction: Staphylococcus aureus is the most common cause of orthopedic infections and can be challenging to treat, especially in the presence of a foreign body. The antistaphylococcal lysins exebacase and CF-296 have rapid bactericidal activity, a low propensity for resistance development, and synergize with some antibiotics. Methods: Rabbit implant-associated osteomyelitis was induced by drilling into the medial tibia followed by locally delivering exebacase, CF-296, or lysin carrier. A titanium screw colonized with methicillin-resistant S. aureus (MRSA) IDRL-6169 was inserted. Intravenous daptomycin or saline was administered and continued daily for 4 d. On day 5, rabbits were euthanized, and the tibiae and implants were collected for culture. Results were reported as log10 colony forming units (cfu) per gram of bone or log10 cfu per implant, and comparisons among the six groups were performed using the Wilcoxon rank sum test. Results: Based on implant and bone cultures, all treatments resulted in significantly lower bacterial counts than those of controls (P≤0.0025). Exebacase alone or with daptomycin as well as CF-296 with daptomycin were more active than daptomycin alone (P≤0.0098) or CF-296 alone (P≤0.0154) based on implant cultures. CF-296 with daptomycin was more active than either CF-296 alone (P=0.0040) or daptomycin alone (P=0.0098) based on bone cultures. Conclusion: Local delivery of either exebacase or CF-296 offers a promising complement to conventional antibiotics in implant-associated infections.</p

    Mechanical loading of stem cells for improvement of transplantation outcome in a model of acute myocardial infarction: the role of loading history

    Get PDF
    Stem cell therapy for tissue repair is a rapidly evolving field and the factors that dictate the physiological responsiveness of stem cells remain under intense investigation. In this study we hypothesized that the mechanical loading history of muscle-derived stem cells (MDSCs) would significantly impact MDSC survival, host tissue angiogenesis, and myocardial function after MDSC transplantation into acutely infarcted myocardium. Mice with acute myocardial infarction by permanent left coronary artery ligation were injected with either nonstimulated (NS) or mechanically stimulated (MS) MDSCs. Mechanical stimulation consisted of stretching the cells with equibiaxial stretch with a magnitude of 10% and frequency of 0.5 Hz. MS cell-transplanted hearts showed improved cardiac contractility, increased numbers of host CD31 + cells, and decreased fibrosis, in the peri-infarct region, compared to the hearts treated with NS MDSCs. MS MDSCs displayed higher vascular endothelial growth factor expression than NS cells in vitro. These findings highlight an important role for cyclic mechanical loading preconditioning of donor MDSCs in optimizing MDSC transplantation for myocardial repair
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