829 resultados para Isopahkala-Bouret, Ulpukka: Joy and struggle for renewal
Resumo:
BACKGROUND: Stem cells with the ability to form clonal floating colonies (spheres) were recently isolated from the neonatal murine spiral ganglion. To further examine the features of inner ear-derived neural stem cells and their derivatives, we investigated the effects of leukemia inhibitory factor (LIF), a neurokine that has been shown to promote self-renewal of other neural stem cells and to affect neural and glial cell differentiation. RESULTS: LIF-treatment led to a dose-dependent increase of the number of neurons and glial cells in cultures of sphere-derived cells. Based on the detection of developmental and progenitor cell markers that are maintained in LIF-treated cultures and the increase of cycling nestin-positive progenitors, we propose that LIF maintains a pool of neural progenitor cells. We further provide evidence that LIF increases the number of nestin-positive progenitor cells directly in a cell cycle-independent fashion, which we interpret as an acceleration of neurogenesis in sphere-derived progenitors. This effect is further enhanced by an anti-apoptotic action of LIF. Finally, LIF and the neurotrophins BDNF and NT3 additively promote survival of stem cell-derived neurons. CONCLUSION: Our results implicate LIF as a powerful tool to control neural differentiation and maintenance of stem cell-derived murine spiral ganglion neuron precursors. This finding could be relevant in cell replacement studies with animal models featuring spiral ganglion neuron degeneration. The additive effect of the combination of LIF and BDNF/NT3 on stem cell-derived neuronal survival is similar to their effect on primary spiral ganglion neurons, which puts forward spiral ganglion-derived neurospheres as an in vitro model system to study aspects of auditory neuron development.
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Potential treatment strategies of neurodegenerative and other diseases with stem cells derived from nonembryonic tissues are much less subjected to ethical criticism than embryonic stem cell-based approaches. Here we report the isolation of inner ear stem cells, which may be useful in cell replacement therapies for hearing loss, after protracted postmortem intervals. We found that neonatal murine inner ear tissues, including vestibular and cochlear sensory epithelia, display remarkably robust cellular survival, even 10 days postmortem. Similarly, isolation of sphere-forming stem cells was possible up to 10 days postmortem. We detected no difference in the proliferation and differentiation potential between stem cells isolated directly after death and up to 5 days postmortem. At longer postmortem intervals, we observed that the potency of sphere-derived cells to spontaneously differentiate into mature cell types diminishes prior to the cells losing their potential for self-renewal. Three-week-old mice also displayed sphere-forming stem cells in all inner ear tissues investigated up to 5 days postmortem. In summary, our results demonstrate that postmortem murine inner ear tissue is suited for isolation of stem cells.
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At the dawn of the 20th century, the burgeoning influence of the Finnish immigrant socialist-unionist movement collided with the authoritative, conservative nature of the Suomi Synod. While the Synod, headquartered in Hancock, Michigan, was attempting to recreate the Finnish state church in America, the quickly radicalizing immigrant socialist-unionist movement was attempting to convert the masses to a materialist message of class struggle manifested by then current conditions in Michigan’s Copper Country and industrial America. The most persuasive voice of class struggle for immigrant Finns at this time was the Finnish-language newspaper Työmies (The Workingman) published in Hancock. Caustic editorials on religion, critical examinations of Christian orthodoxy in translations of Marx and Kropotkin, and ribald cartoons lampooning members of the Synod clergy and laity all demonstrated the overwrought interactions between Työmies and the Synod. This paper will highlight these tense interactions through analysis of doctrine, ideology, and imagery by delving into the primary historical record to reveal the vast gulf between two of the major institutions in early 20th century Finnish immigrant social life.
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A considerable portion of public lands in the United States is at risk of uncharacteristically severe wildfires due to a history of fire suppression. Wildfires already have detrimental impacts on the landscape and on communities in the wildland-urban interface (WUI) due to unnatural and overstocked forests. Strategies to mitigate wildfire risk include mechanical thinning and prescribed burning in areas with high wildfire risk. The material removed is often of little or no economic value. Woody biomass utilization (WBU) could offset the costs of hazardous fuel treatments if removed material could be used for wood products, heat, or electricity production. However, barriers due to transportation costs, removal costs, and physical constraints (such as steep slopes) hinder woody biomass utilization. Various federal and state policies attempt to overcome these barriers. WBU has the potential to aid in wildfire mitigation and meet growing state mandates for renewable energy. This research utilizes interview data from individuals involved with on-the-ground woody biomass removal and utilization to determine how federal and state policies influence woody biomass utilization. Results suggest that there is not one over-arching policy that hinders or promotes woody biomass utilization, but rather woody biomass utilization is hindered by organizational constraints related to time, cost, and quality of land management agencies’ actions. However, the use of stewardship contracting (a hybrid timber sale and service contract) shows promise for increased WBU, especially in states with favorable tax policies and renewable energy mandates. Policy recommendations to promote WBU include renewal of stewardship contracting legislations and a re-evaluation of land cover types suited for WBU. Potential future policies to consider include the indirect role of carbon dioxide emission reduction activities to promote wood energy and future impacts of air quality regulations.
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This dissertation explores the viability of invitational rhetoric as a mode of advocacy for sustainable energy use in the residential built environment. The theoretical foundations for this study join ecofeminist concepts and commitments with the conditions and resources of invitational rhetoric, developing in particular the rhetorical potency of the concepts of re-sourcement and enfoldment. The methodological approach is autoethnography using narrative reflection and journaling, both adapted to and developed within the autoethnographic project. Through narrative reflection, the author explores her lived experiences in advocating for energy-responsible residential construction in the Keweenaw Peninsula of Michigan. The analysis reveals the opportunities for cooperative, collaborative advocacy and the struggle against traditional conventions of persuasive advocacy, particularly the centrality of the rhetor. The author also conducted two field trips to India, primarily the state of Kerala. Drawing on autoethnographic journaling, the analysis highlights the importance of sensory relations in lived advocacy and the resonance of everyday Indian culture to invitational principles. Based on field research, the dissertation proposes autoethnography as a critical development in encouraging invitational rhetoric as an alternative mode of effecting change. The invitational force of autoethnography is evidenced in portraying the material advocacy of the built environment itself, specifically the sensual experience of material arrangements and ambience, as well as revealing the corporeality of advocacy, that is, the body as the site of invitational engagement, emotional encounter, and sensory experience. This study concludes that vulnerability of self in autoethnographic work and the vulnerability of rhetoric as invitational constitute the basis for transformation. The dissertation confirms the potential of an ecofeminist invitational advocacy conveyed autoethnographically for transforming perceptions and use of energy in a smaller-scale residential environment appropriate for culture, climate, and ultimately part of the challenge of sustaining life on this planet.
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Small-scale farmers in the Chipata District of Zambia rely on their farm fields to grow maize and groundnuts for food security. Cotton production and surplus food security crops are used to generate income to provide for their families. With increasing population pressure, available land has decreased and farmers struggle to provide the necessary food requirements and income to meet their family’s needs. The purpose of the study was to determine how a farmer can best allocate his land to produce maize, groundnuts and cotton when constrained by labor and capital resources to generate the highest potential for food security and financial gains. Data from the 2008-2009 growing season was compiled and analyzed using a linear programming model. The study determined that farmers make the most profit by allocating all additional land and resources to cotton after meeting their minimum food security requirements. The study suggests growing cotton is a beneficial practice for small-scale subsistence farmers to generate income when restricted by limited resources.
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The expression pattern of angiotensin AT2 receptors with predominance during fetal life and upregulation under pathological conditions during tissue injury/repair process suggests that AT2 receptors may exert an important action in injury/repair adaptive mechanisms. Less is known about AT2 receptors in acute ischemia-induced cardiac injury. We aimed here to elucidate the role of AT2 receptors after acute myocardial infarction. Double immunofluorescence staining showed that cardiac AT2 receptors were mainly detected in clusters of small c-kit+ cells accumulating in peri-infarct zone and c-kit+AT2+ cells increased in response to acute cardiac injury. Further, we isolated cardiac c-kit+AT2+ cell population by modified magnetic activated cell sorting and fluorescence activated cell sorting. These cardiac c-kit+AT2+ cells, represented approximately 0.19% of total cardiac cells in infarcted heart, were characterized by upregulated transcription factors implicated in cardiogenic differentiation (Gata-4, Notch-2, Nkx-2.5) and genes required for self-renewal (Tbx-3, c-Myc, Akt). When adult cardiomyocytes and cardiac c-kit+AT2+ cells isolated from infarcted rat hearts were cocultured, AT2 receptor stimulation in vitro inhibited apoptosis of these cocultured cardiomyocytes. Moreover, in vivo AT2 receptor stimulation led to an increased c-kit+AT2+ cell population in the infarcted myocardium and reduced apoptosis of cardiomyocytes in rats with acute myocardial infarction. These data suggest that cardiac c-kit+AT2+ cell population exists and increases after acute ischemic injury. AT2 receptor activation supports performance of cardiomyocytes, thus contributing to cardioprotection via cardiac c-kit+AT2+ cell population.
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Neurogenesis in the adult mouse brain occurs within the subventricular zone (SVZ) of the lateral ventricle. In the SVZ, neural stem cells (NSC) reside in a specialized microenvironment, or vascular niche, consisting of blood vessels and their basement membranes. Most NSCs in the SVZ differentiate into progenitor cells, which further differentiate to generate neuroblasts, which then migrate from the SVZ to the olfactory bulbs (OB) along the rostral migratory stream (RMS). ECM-mediated adhesion and signaling within the vascular niche likely contribute to proper NSC self-renewal, survival, differentiation and neuroblast motility. The mechanisms that control these events are poorly understood. Previous studies from our group and others have shown that loss of the ECM receptor, αvβ8 integrin, in NSCs in the embryonic mouse brain leads to severe developmental vascular defects and premature death. Here, the functions of αvβ8 integrin in the adult brain have been examined using mice that have been genetically manipulated to lack a functional β8 integrin gene. This study reveals that loss of β8 integrin leads to widespread defects in homeostasis of the neurovascular unit, including increased intracerebral blood vessels with enhanced perivascular astrogliosis. Additionally, β8 integrin dependent defects in NSC proliferation, survival, and differentiation, as well as neuroblast migration in the RMS were observed both in vivo and in vitro. The defects correlated, in part, with diminished integrin-mediated activation of TGFβ, an ECM ligand of β8 integrin. Collectively, these data identify important adhesion and signaling functions for β8 integrin in the regulation of neural stem and progenitor cells in the SVZ as well as in neuroblast migration along the RMS in the adult brain.
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BACKGROUND: Alcohol dependence is extremely common in patients with bipolar disorder and is associated with unfavorable outcomes including treatment nonadherence, violence, increased hospitalization, and decreased quality of life. While naltrexone is a standard treatment for alcohol dependence, no controlled trials have examined its use in patients with co-morbid bipolar disorder and alcohol dependence. In this pilot study, the efficacy of naltrexone in reducing alcohol use and on mood symptoms was assessed in bipolar disorder and alcohol dependence. METHODS: Fifty adult outpatients with bipolar I or II disorders and current alcohol dependence with active alcohol use were randomized to 12 weeks of naltrexone (50 mg/d) add-on therapy or placebo. Both groups received manual-driven cognitive behavioral therapy designed for patients with bipolar disorder and substance-use disorders. Drinking days and heavy drinking days, alcohol craving, liver enzymes, and manic and depressed mood symptoms were assessed. RESULTS: The 2 groups were similar in baseline and demographic characteristics. Naltrexone showed trends (p < 0.10) toward a greater decrease in drinking days (binary outcome), alcohol craving, and some liver enzyme levels than placebo. Side effects were similar in the 2 groups. Response to naltrexone was significantly related to medication adherence. CONCLUSIONS: Results suggest the potential value and acceptable tolerability of naltrexone for alcohol dependence in bipolar disorder patients. A larger trial is needed to establish efficacy.
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Much of the craniofacial skeleton, such as the skull vault, mandible and midface, develops through direct, intramembranous ossification of the cranial neural crest (CNC) derived progenitor cells. Bmp-signaling plays critical roles in normal craniofacial development, and Bmp4 deficiency results in craniofacial abnormalities, such as cleft lip and palate. We performed an in depth analysis of Bmp4, a critical regulator of development, disease, and evolution, in the CNC. Conditional Bmp4 overexpression, using a tetracycline regulated Bmp4 gain of function allele, resulted in facial form changes that were most dramatic after an E10.5 Bmp4 induction. Expression profiling uncovered a signature of Bmp4 induced genes (BIG) composed predominantly of transcriptional regulators controlling self-renewal, osteoblast differentiation, and negative Bmp autoregulation. The complimentary experiment, CNC inactivation of Bmp2, Bmp4, and Bmp7, resulted in complete or partial loss of multiple CNC derived skeletal elements revealing a critical requirement for Bmp-signaling in membranous bone and cartilage development. Importantly, the BIG signature was reduced in Bmp loss of function mutants indicating similar Bmp-regulated target genes underlying facial form modulation and normal skeletal morphogenesis. Chromatin immunoprecipitation (ChIP) revealed a subset of the BIG signature, including Satb2, Smad6, Hand1, Gadd45g and Gata3 that was bound by Smad1/5 in the developing mandible revealing direct, Smad-mediated regulation. These data indicate that Bmp-signaling regulates craniofacial skeletal development and facial form by balancing self-renewal and differentiation pathways in CNC progenitors.
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Starting with the premise that extended family members often have great influence on family functioning, this article describes social work practice techniques for helping families utilize resources available in the extended family network. Two key concepts are presented: "parenting pioneers," who, while attempting newly learned parenting skills, may struggle with resistance from extended family members; and "parenting teams," in which the focal family is giving to or receiving from extended family members substantial family support. The article presents these practice techniques in the context of family support services, which are characterized as voluntary, preventive, developmental, and based in the concept of empowerment and the ecological perspective.
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America’s low-income families struggle to protect their children from multiple threats to their health and growth. Many research and advocacy groups explore the health and educational effects of food insecurity, but less is known about these effects on very young children. Children’s HealthWatch, a group of pediatric clinicians and public health researchers, has continuously collected data on the effects of food insecurity alone and in conjunction with other household hardships since 1998. The group’s peer reviewed research has shown that a number of economic risks at the household level, including food, housing and energy insecurity, tend to be correlated. These insecurities alone or in conjunction increase the risk that a young child will suffer various negative health consequences, including increases in lifetime hospitalizations, parental report of fair or poor health,1 or risk for developmental delays.2 Child food insecurity is an incremental risk indicator above and beyond the risk imposed by household-level food insecurity. The Children’sHealthwatch research also suggests public benefits programs modify some of these effects for families experiencing hardships. This empirical evidence is presented in a variety of public venues outside the usual scientific settings, such as congressional hearings, to support the needs of America’s most vulnerable population through policy change. Children’s HealthWatch research supports legislative solutions to food insecurity, including sustained funding for public programs and re-evaluation of the use of the Thrifty Food Plan as the basis of SNAP benefits calculations. Children’s HealthWatch is one of many models to support the American Academy of Pediatrics’ call to “stand up, speak up, and step up for children.”3 No isolated group or single intervention will solve child poverty or multiple hardships. However, working collaboratively each group has a role to play in supporting the health and well-being of young children and their families. 1. Cook JT, Frank DA, Berkowitz C, et al. Food insecurity is associated with adverse health outcomes among human infants and toddlers. J Nutr. 2004;134:1432-1438. 2. Rose-Jacobs R, Black MM, Casey PH, et al. Household food insecurity: associations with at-risk infant and toddler development. Pediatrics. 2008;121:65-72. 3. AAP leader says to stand up, speak up, and step up for child health [news release]. Boston, MA: American Academy of Pediatrics; October 11, 2008. http://www2.aap.org/pressroom/nce/nce08childhealth.htm. Accessed January 1, 2012.
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The sustainability of regional development can be usefully explored through several different lenses. In situations in which uncertainties and change are key features of the ecological landscape and social organization, critical factors for sustainability are resilience, the capacity to cope and adapt, and the conservation of sources of innovation and renewal. However, interventions in social-ecological systems with the aim of altering resilience immediately confront issues of governance. Who decides what should be made resilient to what? For whom is resilience to be managed, and for what purpose? In this paper we draw on the insights from a diverse set of case studies from around the world in which members of the Resilience Alliance have observed or engaged with sustainability problems at regional scales. Our central question is: How do certain attributes of governance function in society to enhance the capacity to manage resilience? Three specific propositions were explored: ( 1) participation builds trust, and deliberation leads to the shared understanding needed to mobilize and self-organize; ( 2) polycentric and multilayered institutions improve the fit between knowledge, action, and social-ecological contexts in ways that allow societies to respond more adaptively at appropriate levels; and ( 3) accountable authorities that also pursue just distributions of benefits and involuntary risks enhance the adaptive capacity of vulnerable groups and society as a whole. Some support was found for parts of all three propositions. In exploring the sustainability of regional social-ecological systems, we are usually faced with a set of ecosystem goods and services that interact with a collection of users with different technologies, interests, and levels of power. In this situation in our roles as analysts, facilitators, change agents, or stakeholders, we not only need to ask: The resilience of what, to what? We must also ask: For whom?