110 research outputs found
In Vitro Multitissue Interface Model Supports Rapid Vasculogenesis and Mechanistic Study of Vascularization across Tissue Compartments
A significant challenge facing tissue engineers is the design and development of complex multitissue systems, including vascularized tissue-tissue interfaces. While conventional in vitro models focus on either vasculogenesis (de novo formation of blood vessels) or angiogenesis (vessels sprouting from existing vessels or endothelial monolayers), successful therapeutic vascularization strategies will likely rely on coordinated integration of both processes. To address this challenge, we developed a novel in vitro multitissue interface model in which human endothelial colony forming cell (ECFC)-encapsulated tissue spheres are embedded within a surrounding tissue microenvironment. This highly reproducible approach exploits biphilic surfaces (nanostructured surfaces with distinct superhydrophobic and hydrophilic regions) to (i) support tissue compartments with user-specified matrix composition and physical properties as well as cell type and density and (ii) introduce boundary conditions that prevent the cell-mediated tissue contraction routinely observed with conventional three-dimensional monodispersion cultures. This multitissue interface model was applied to test the hypothesis that independent control of cell-extracellular matrix (ECM) and cell-cell interactions would affect vascularization within the tissue sphere as well as across the tissue-tissue interface. We found that high-cell-density tissue spheres containing 5 × 10(6) ECFCs/mL exhibit rapid and robust vasculogenesis, forming highly interconnected, stable (as indicated by type IV collagen deposition) vessel networks within only 3 days. Addition of adipose-derived stromal cells (ASCs) in the surrounding tissue further enhanced vasculogenesis within the sphere as well as angiogenic vessel elongation across the tissue-tissue boundary, with both effects being dependent on the ASC density. Overall, results show that the ECFC density and ECFC-ASC crosstalk, in terms of paracrine and mechanophysical signaling, are critical determinants of vascularization within a given tissue compartment and across tissue interfaces. This new in vitro multitissue interface model and the associated mechanistic insights it yields provide guiding principles for the design and optimization of multitissue vascularization strategies for research and clinical applications
Reliability of Striatal [11C]Raclopride Binding in Smokers Wearing Transdermal Nicotine Patches
PURPOSE:
In studies where [(11)C]raclopride (RAC) positron emission tomography (PET) is used to assess changes in striatal dopamine, it is important to control for cognitive states, such as drug craving, that could alter dopamine levels. In cigarette smokers, transdermal nicotine patches (TNP) can control nicotine craving, but the effects of nicotine patches on RAC binding are unknown. Thus, we sought to determine the test-retest reliability of RAC binding in the presence of nicotine patches.
METHODS:
Eleven male smokers were scanned twice with RAC on separate days while wearing TNP.
RESULTS:
Across the striatum, test-retest variability was 7.63 ± 5.88; percent change in binding potential was 1.11 ± 9.83; and the intraclass correlation coefficient was 0.91 (p < 0.0001).
CONCLUSION:
Baseline RAC binding is highly reproducible in smokers wearing nicotine patches. This suggests that TNP are an acceptable method for controlling cigarette craving during studies that utilize RAC to examine changes in dopamine
Impact of family abuse on running away, deviance, and street victimization among homeless rural and urban youth
Problem — Various demographic and familial risk factors have been linked to runaway behavior. To date, there has not been a systematic investigation of the impact of size of community on runaway behavior. This study will compare runaways from smaller cities and rural areas to their urban counterparts.
Methods — A convenience sample of 602 adolescents was interviewed between 1995 and August of 1996 in Missouri, Iowa, Nebraska, and Kansas, USA. Multiple regression was used to examine the association between gender, neglect, sexual abuse, physical abuse, geographic and family structure change, and community size of first runaway to predict age at first runaway, deviant subsistence strategies, and street victimization.
Results — Findings indicate that adolescents exposed to neglect (β = −.20) and sexual abuse (β = −.16) ran away sooner and were more likely to be victimized on the street. Rural adolescents who experienced higher levels of physical abuse relied more heavily on deviant subsistence strategies (β = .15) and remained in abusive homes longer (β = .15) than their similarly situated urban counterparts.
Conclusions — Rural youth who have been subjected to elevated levels of familial abuse are at greater risk of deviant subsistence strategies, which increase the likelihood of street victimization
A Dimensional Model of Psychopathology Among Homeless Adolescents: Suicidality, Internalizing, and Externalizing Disorders
The present study examined associations among dimensions of suicidality and psychopathology in a sample of 428 homeless adolescents (56.3% female). Confirmatory factor analysis results provided support for a three-factor model in which suicidality (measured with lifetime suicidal ideation and suicide attempts), internalizing disorders (assessed with lifetime diagnoses of major depressive episode and post-traumatic stress disorder), and externalizing disorders (indicated by lifetime diagnoses of conduct disorder, alcohol abuse, and drug abuse) were positively intercorrelated. The findings illustrate the utility of a dimensional approach that integrates suicidality and psychopathology into one model
Mechanistic insight into proton-coupled mixed valency
Stabilisation of the mixed-valence state in [Mo2(TiPB)3(HDOP)]2+ (HTiPB = 2,4,6-triisopropylbenzoic acid, H2DOP = 3,6-dihydroxypyridazine) by electron transfer (ET) is related to the proton coordinate of the bridging ligands. Spectroelectrochemical studies suggest that ET is slower than 109 s−1. The mechanism has been probed using DFT calculations, which show that proton transfer induces a larger dipole in the molecule resulting in ET
Mobile Technology Intervention for Weight Loss in Rural Men: Protocol for a Pilot Pragmatic Randomised Controlled Trial
INTRODUCTION: Men who are overweight or obese in the rural Midwestern USA are an unrepresented, at-risk group exhibiting rising rates of cardiovascular disease, poor access to preventive care and poor lifestyle behaviours that contribute to sedentary lifestyle and unhealthy diet. Self-monitoring of eating and activity has demonstrated efficacy for weight loss. Use of mobile technologies for self-monitoring eating and activity may address rural men\u27s access disparities to preventive health resources and support weight loss. Our pilot trial will assess the feasibility and acceptability of two mobile applications for weight loss in rural men to inform a future, full-scale trial.
METHODS AND ANALYSIS: A 6-month randomised controlled trial with contextual evaluation will randomise 80 men using a 1:1 ratio to either a Mobile Technology Plus (MT+) intervention or a basic Mobile Technology (MT) intervention in rural, midlife men (aged 40-69 years). The MT+ intervention consists of a smartphone self-monitoring application enhanced with discussion group (Lose-It premium), short message service text-based support and Wi-Fi scale. The MT group will receive only a self-monitoring application (Lose-It basic). Feasibility and acceptability will be evaluated using number of men recruited and retained, and evaluative focus group feedback. We seek to determine point estimates and variability of outcome measures of weight loss (kg and % body weight) and improved dietary and physical activity behaviours (Behavioral Risk Factor Surveillance System (BRFSS) physical activity and fruit and vegetable consumption surveys, data from Lose-It! application (kcal/day, steps/day)). Community capacity will be assessed using standard best practice methods. Descriptive content analysis will evaluate intervention acceptability and contextual sensitivity.
ETHICS AND DISSEMINATION: This protocol was approved by the University of Nebraska Medical Center Institutional Review Board (IRB# 594-17-EP). Dissemination of findings will occur through ClinicalTrials.gov and publish pilot data to inform the design of a larger clinical trial.
TRIAL REGISTRATION NUMBER: NCT03329079; preresults. Protocol V.10, study completion date 31 August 2020. Roles and responsibilities funder: NIH/NINR Health Disparities Section 1R15NR017522-01
Functional Morphology of Secretion by the Large Wax Glands (Sensilla Sagittiformia) Involved in Tick Defense
Assessment of Corticosteroid Therapy and Death or Disability According to Pretreatment Risk of Death or Bronchopulmonary Dysplasia in Extremely Preterm Infants
IMPORTANCE: Meta-analyses suggest that corticosteroids may be associated with increased survival without cerebral palsy in infants at high risk of bronchopulmonary dysplasia (BPD) but are associated with adverse neurologic outcomes in low-risk infants. Whether this association exists in contemporary practice is uncertain because most randomized clinical trials administered corticosteroids earlier and at higher doses than currently recommended.
OBJECTIVE: To evaluate whether the pretreatment risk of death or grade 2 or 3 BPD at 36 weeks\u27 postmenstrual age modified the association between postnatal corticosteroid therapy and death or disability at 2 years\u27 corrected age in extremely preterm infants.
DESIGN, SETTING, AND PARTICIPANTS: This cohort study analyzed data on 482 matched pairs of infants from 45 participating US hospitals in the National Institute of Child Health and Human Development Neonatal Research Network Generic Database (GDB). Infants were included in the cohort if they were born at less than 27 weeks\u27 gestation between April 1, 2011, and March 31, 2017; survived the first 7 postnatal days; and had 2-year death or developmental follow-up data collected between January 2013 and December 2019. Corticosteroid-treated infants were propensity score matched with untreated controls. Data were analyzed from September 1, 2019, to November 30, 2022.
EXPOSURE: Systemic corticosteroid therapy to prevent BPD that was initiated between day 8 and day 42 after birth.
MAIN OUTCOMES AND MEASURES: The primary outcome was death or moderate to severe neurodevelopmental impairment at 2 years\u27 corrected age. The secondary outcome was death or moderate to severe cerebral palsy at 2 years\u27 corrected age.
RESULTS: A total of 482 matched pairs of infants (mean [SD] gestational age, 24.1 [1.1] weeks]; 270 males [56.0%]) were included from 656 corticosteroid-treated infants and 2796 potential controls. Most treated infants (363 [75.3%]) received dexamethasone. The risk of death or disability associated with corticosteroid therapy was inversely associated with the estimated pretreatment probability of death or grade 2 or 3 BPD. The risk difference for death or neurodevelopmental impairment associated with corticosteroids decreased by 2.7% (95% CI, 1.9%-3.5%) for each 10% increase in the pretreatment risk of death or grade 2 or 3 BPD. This risk transitioned from estimated net harm to benefit when the pretreatment risk of death or grade 2 or 3 BPD exceeded 53% (95% CI, 44%-61%). For death or cerebral palsy, the risk difference decreased by 3.6% (95% CI, 2.9%-4.4%) for each 10% increase in the risk of death or grade 2 or 3 BPD and transitioned from estimated net harm to benefit at a pretreatment risk of 40% (95% CI, 33%-46%).
CONCLUSIONS AND RELEVANCE: Results of this study suggested that corticosteroids were associated with a reduced risk of death or disability in infants at moderate to high pretreatment risk of death or grade 2 or 3 BPD but with possible harm in infants at lower risk
The Grizzly, September 4, 2003
A Space to Call Your Own • Pay for Print Solution • Bumpy Ride • Spotlight on Politics: The California Recall • Feeling Disconnected: Internet and Virus Woes • A Plan for Every Future: Career Services Fall 2003 • Opinions: Campus Rooms: Is Space Running Out?; Network Gripes Getting you Down? Elections in California: Business as Usual or Free for All? • Activities, Activities, Activities • Calling all Thespians! • Ursinus in 1893: What was it Like? • New Arts Center • Local Heritage Day Celebration • Bears Versatility Makes the Season Look Promising • UC Field Hockey Team: Ready to Rumble • Promising Season Abound for the Men and Women\u27s Soccer Teams • Ursinus Cross Country Kicks-off • Ursinus Volleyball Team Off to Rough Start • X-Country Team Scoreshttps://digitalcommons.ursinus.edu/grizzlynews/1539/thumbnail.jp
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