University of Kentucky

About: University of Kentucky is a education organization based out in Lexington, Kentucky, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 43933 authors who have published 92195 publications receiving 3256087 citations. The organization is also known as: UK.

Evidence that brain-derived neurotrophic factor is required for basal neurogenesis and mediates, in part, the enhancement of neurogenesis by dietary restriction in the hippocampus of adult mice

Abstract: To determine the role of brain-derived neurotrophic factor (BDNF) in the enhancement of hippocampal neurogenesis resulting from dietary restriction (DR), heterozygous BDNF knockout (BDNF +/-) mice and wild-type mice were maintained for 3 months on DR or ad libitum (AL) diets Mice were then injected with bromodeoxyuridine (BrdU) and killed either 1 day or 4 weeks later Levels of BDNF protein in neurons throughout the hippocampus were decreased in BDNF +/- mice, but were increased by DR in wild-type mice and to a lesser amount in BDNF +/- mice One day after BrdU injection the number of BrdU-labeled cells in the dentate gyrus of the hippocampus was significantly decreased in BDNF +/- mice maintained on the AL diet, suggesting that BDNF signaling is important for proliferation of neural stem cells DR had no effect on the proliferation of neural stem cells in wild-type or BDNF +/- mice Four weeks after BrdU injection, numbers of surviving labeled cells were decreased in BDNF +/- mice maintained on either AL or DR diets DR significantly improved survival of newly generated cells in wild-type mice, and also improved their survival in BDNF +/- mice, albeit to a lesser extent The majority of BrdU-labeled cells in the dentate gyrus exhibited a neuronal phenotype at the 4-week time point The reduced neurogenesis in BDNF +/- mice was associated with a significant reduction in the volume of the dentate gyrus These findings suggest that BDNF plays an important role in the regulation of the basal level of neurogenesis in dentate gyrus of adult mice, and that by promoting the survival of newly generated neurons BDNF contributes to the enhancement of neurogenesis induced by DR

Landscapes: The Social Construction of Nature and the Environment

Abstract: A theoretical framework is provided to understand a cultural group's definition of and relationship with nature and the environment. The framework draws on a social constructionist perspective that includes aspects of phenomenology and symbolic interactionism to define “landscape” as the symbolic environment created by a human act of conferring meaning on nature and the environment. This landscape reflects the selfdefinitions of the people within a particular cultural context. Attention is directed to transformation of the physical environment into landscapes that reflect people's definitions of themselves and on how these landscapes are reconstructed in response to people's changing definitions of themselves. Case studies from sociology and anthropology illustrate the social construction of nature and the environment. A discussion of the applied implications of the theoretical framework in social impact assessment and the global implications in the shifting power struggle over competing landscapes concludes the paper.

Sequence- and target-independent angiogenesis suppression by siRNA via TLR3

Abstract: Clinical trials of small interfering RNA (siRNA) targeting vascular endothelial growth factor-A (VEGFA) or its receptor VEGFR1 (also called FLT1), in patients with blinding choroidal neovascularization (CNV) from age-related macular degeneration, are premised on gene silencing by means of intracellular RNA interference (RNAi). We show instead that CNV inhibition is a siRNA-class effect: 21-nucleotide or longer siRNAs targeting non-mammalian genes, non-expressed genes, non-genomic sequences, pro- and anti-angiogenic genes, and RNAi-incompetent siRNAs all suppressed CNV in mice comparably to siRNAs targeting Vegfa or Vegfr1 without off-target RNAi or interferon-α/β activation. Non-targeted (against non-mammalian genes) and targeted (against Vegfa or Vegfr1) siRNA suppressed CNV via cell-surface toll-like receptor 3 (TLR3), its adaptor TRIF, and induction of interferon-γ and interleukin-12. Non-targeted siRNA suppressed dermal neovascularization in mice as effectively as Vegfa siRNA. siRNA-induced inhibition of neovascularization required a minimum length of 21 nucleotides, a bridging necessity in a modelled 2:1 TLR3–RNA complex. Choroidal endothelial cells from people expressing the TLR3 coding variant 412FF were refractory to extracellular siRNA-induced cytotoxicity, facilitating individualized pharmacogenetic therapy. Multiple human endothelial cell types expressed surface TLR3, indicating that generic siRNAs might treat angiogenic disorders that affect 8% of the world’s population, and that siRNAs might induce unanticipated vascular or immune effects.

Electromechanical integration of cardiomyocytes derived from human embryonic stem cells.

Abstract: Cell therapy is emerging as a promising strategy for myocardial repair. This approach is hampered, however, by the lack of sources for human cardiac tissue and by the absence of direct evidence for functional integration of donor cells into host tissues. Here we investigate whether cells derived from human embryonic stem (hES) cells can restore myocardial electromechanical properties. Cardiomyocyte cell grafts were generated from hES cells in vitro using the embryoid body differentiating system. This tissue formed structural and electromechanical connections with cultured rat cardiomyocytes. In vivo integration was shown in a large-animal model of slow heart rate. The transplanted hES cell-derived cardiomyocytes paced the hearts of swine with complete atrioventricular block, as assessed by detailed three-dimensional electrophysiological mapping and histopathological examination. These results demonstrate the potential of hES-cell cardiomyocytes to act as a rate-responsive biological pacemaker and for future myocardial regeneration strategies.

Surviving sepsis campaign: international guidelines for management of sepsis and septic shock 2021.

Abstract: Background Sepsis poses a global threat to millions of lives. The Surviving Sepsis Campaign (SSC) guidelines provide evidence-based recommendations on the recognition and management of sepsis and its complications. Methods We formed a panel of 60 experts from 22 countries and 11 members of the public. The panel prioritized questions that are relevant to the recognition and management of sepsis and septic shock in adults. New questions and sections were addressed, relative to the previous guidelines. These questions were grouped under 6 subgroups (screening and early treatment, infection, hemodynamics, ventilation, additional therapies, and long-term outcomes and goals of care). With input from the panel and methodologists, professional medical librarians performed the search strategy tailored to either specific questions or a group of relevant questions. A dedicated systematic review team performed screening and data abstraction when indicated. For each question, the methodologists, with input from panel members, summarized the evidence assessed and graded the quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. The panel generated recommendations using the evidence-to-decision framework. Recommendations were either strong or weak, or in the form of best practice statements. When evidence was insufficient to support a recommendation, the panel was surveyed to generate “in our practice” statements. Results The SSC panel issued 93 statements: 15 best practice statements, 15 strong recommendations, and 54 weak recommendations and no recommendation was provided for 9 questions. The recommendations address several important clinical areas related to screening tools, acute resuscitation strategies, management of fluids and vasoactive agents, antimicrobials and diagnostic tests and the use of additional therapies, ventilation management, goals of care, and post sepsis care. Conclusion The SSC panel issued evidence-based recommendations to help support key stakeholders caring for adults with sepsis or septic shock and their families.