1,246 research outputs found

    Luminescence and fluorescence of essential oils. Fluorescence imaging in vivo of wild chamomile oil

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    Essential oils are currently of great importance to pharmaceutical companies, cosmetics producers and manufacturers of veterinary products. They are found in perfumes, creams, bath products, and household cleaning substances, and are used for flavouring food and drinks. It is well known that some of them act on the respiratory apparatus. The increasing interest in optical imaging techniques and the development of related technologies have made possible the investigation of the optical properties of several compounds. Luminescent properties of essential oils have not been extensively investigated. We evaluated the luminescent and fluorescent emissions of several essential oils, in order to detect them in living organisms by exploiting their optical properties. Some fluorescent emission data were high enough to be detected in dermal treatments. Consequently, we demonstrated how the fluorescent signal can be monitored for at least three hours on the skin of living mice treated with wild chamomile oil. The results encourage development of this technique to investigate the properties of drugs and cosmetics containing essential oils

    Evidence That Ultraviolet Radiation May Depress Short-Term Photosynthetic Rates of Intertidal Ulva lactuca and Consumption by a Generalist Feeder (Clibanarius vittatus)

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    This article considers the impact of ultraviolet radiation (UVR) on the photosynthesis and consumption of intertidal Ulva lactuca, an important producer and food resource in many coastal ecosystems. Algal fragments were exposed in the laboratory to either UVR and PAR (photosynthetically active radiation) simultaneously or PAR alone. The rates of photosynthesis and consumption by a generalist feeder, the stripped hermit crab (Clibanarius vittatus), were then compared between the two treatments. In both experiments, the biological weighted values for UVR in the laboratory indicate that the experimental set-up provided a level of UVR exposure that would occur in the field. The results show that UVR exposure depresses the photosynthetic rates of U. lactuca at light intensities between 1118 and 2206 μmol m-2 s-1. UVR also reduced the grazing intensity of C. vittatus on U. lactuca with non-UVR-exposed algal pieces supporting about five times more consumption than exposed pieces. The relevance and implications of this study, however, are limited because the results have been obtained with short-term, simple experiments. Studies encompassing a longer time scale and the community of consumers (e.g. exposing both the algae and main consumers simultaneously to experimental UVR levels) are needed to elucidate whether the algae can offset UVR-deleterious effects through the induction of protective compounds and how these compounds and UVR exposure affects the activity of consumers

    Biomimetic engineered muscle with capacity for vascular integration and functional maturation in vivo.

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    Tissue-engineered skeletal muscle can serve as a physiological model of natural muscle and a potential therapeutic vehicle for rapid repair of severe muscle loss and injury. Here, we describe a platform for engineering and testing highly functional biomimetic muscle tissues with a resident satellite cell niche and capacity for robust myogenesis and self-regeneration in vitro. Using a mouse dorsal window implantation model and transduction with fluorescent intracellular calcium indicator, GCaMP3, we nondestructively monitored, in real time, vascular integration and the functional state of engineered muscle in vivo. During a 2-wk period, implanted engineered muscle exhibited a steady ingrowth of blood-perfused microvasculature along with an increase in amplitude of calcium transients and force of contraction. We also demonstrated superior structural organization, vascularization, and contractile function of fully differentiated vs. undifferentiated engineered muscle implants. The described in vitro and in vivo models of biomimetic engineered muscle represent enabling technology for novel studies of skeletal muscle function and regeneration

    Z-scores of fetal bladder distention for the antenatal differential diagnosis of posterior urethral valves and urethral atresia

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    Objective: To construct reference values for fetal urinary bladder distension in pregnancy and use Z-scores as a diagnostic tool to differentiate posterior urethral valves (PUV) from urethral atresia (UA). Methods: This was a prospective cross-sectional study in healthy singleton pregnancies aimed at constructing nomograms of fetal urinary bladder diameter and volume between 15 and 35 weeks' gestation. Z-scores of longitudinal bladder diameter (LBD) were calculated and validated in a cohort of fetuses with megacystis with ascertained postnatal or postmortem diagnosis, collected from a retrospective, multicenter study. Correlations between anatomopathological findings, based on medical examination of the infant or postmortem examination, and fetal megacystis were established. The accuracy of the Z-scores was evaluated by receiver-operating-characteristics (ROC)-curve analysis. Results: Nomograms of fetal urinary bladder diameter and volume were produced from three-dimensional ultrasound volumes in 225 pregnant women between 15 and 35 weeks of gestation. A total of 1238 urinary bladder measurements were obtained. Z-scores, derived from the fetal nomograms, were calculated in 106 cases with suspected lower urinary tract obstruction (LUTO), including 76 (72%) cases with PUV, 22 (21%) cases with UA, four (4%) cases with urethral stenosis and four (4%) cases with megacystis-microcolon-intestinal hypoperistalsis syndrome. Fetuses with PUV showed a significantly lower LBD Z-score compared to those with UA (3.95 vs 8.83, P < 0.01). On ROC-curve analysis, we identified 5.2 as the optimal Z-score cut-off to differentiate fetuses with PUV from the rest of the study population (area under the curve, 0.84 (95% CI, 0.748–0.936); P < 0.01; sensitivity, 74%; specificity, 86%). Conclusions: Z-scores of LBD can distinguish reliably fetuses with LUTO caused by PUV from those with other subtypes of LUTO, with an optimal cut-off of 5.2. This information should be useful for prenatal counseling and management of LUTO

    Stem-like and highly invasive prostate cancer cells expressing CD44v8-10 marker originate from CD44-negative cells

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    In human prostate cancer (PCa), the neuroendocrine cells, expressing the prostate cancer stem cell (CSC) marker CD44, may be resistant to androgen ablation and promote tumor recurrence. During the study of heterogeneity of the highly aggressive neuroendocrine PCa cell lines PC3 and DU-145, we isolated and expanded in vitro a minor subpopulation of very small cells lacking CD44 (CD44neg). Unexpectedly, these sorted CD44neg cells rapidly and spontaneously converted to a stable CD44high phenotype specifically expressing the CD44v8-10 isoform which the sorted CD44high subpopulation failed to express. Surprisingly and potentially interesting, in these cells expression of CD44v8-10 was found to be induced in stem cell medium. CD44 variant isoforms are known to be more expressed in CSC and metastatic cells than CD44 standard isoform. In agreement, functional analysis of the two sorted and cultured subpopulations has shown that the CD44v8-10pos PC3 cells, resulting from the conversion of the CD44neg subpopulation, were more invasive in vitro and had a higher clonogenic potential than the sorted CD44high cells, in that they produced mainly holoclones, known to be enriched in stem-like cells. Of interest, the CD44v8-10 is more expressed in human PCa biopsies than in normal gland. The discovery of CD44v8-10pos cells with stem-like and invasive features, derived from a minoritarian CD44neg cell population in PCa, alerts on the high plasticity of stem-like markers and urges for prudency on the approaches to targeting the putative CSC

    Early stages of divergence: phylogeography, climate modeling, and morphological differentiation in the South American lizard Liolaemus petrophilus (Squamata: Liolaemidae)

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    This study examines the phylogeographic structure within the Patagonian lizard Liolaemus petrophilus and tests for patterns of between-clade morphological divergence and sexual dimorphism as well as demographic and niche changes associated with Pleistocene climate changes. We inferred intra-specific relationships, tested hypotheses for historical patterns of  population expansion, and incorporated ecological niche modeling (ENM) with standard  morphological and geometric morphometric analyses to examine between-clade divergence as indirect evidence for adaptation to different niches. The two inferred haploclades diverged during the early Pleistocene with the Southern clade depicting the genetic signature of a recent population increase associated with expanding niche envelope, whereas the Northern clade shows stable populations in a shrinking niche envelope. The combination of molecular evidence for post-isolation demographic change and ENM, suggest that the two haploclades have responded differently to Pleistocene climatic events.Fil: Fontanella, Frank M.. Morehead State University; Estados UnidosFil: Feltrin, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Avila, Luciano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Sites, Jack W.. University Brigham Young; Estados UnidosFil: Morando, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

    Performance of the FMF First-Trimester Preeclampsia-Screening Algorithm in a High-Risk Population in The Netherlands

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    OBJECTIVE: The aim of the study was to evaluate the performance of the first-trimester Fetal Medicine Foundation (FMF) screening algorithm, including maternal characteristics and medical history, blood pressure, pregnancy-associated plasma protein A and placenta growth factor, crown rump length, and uterine artery pulsatility index, for the prediction of preeclampsia in a high-risk population in the Netherlands. METHODS: This is a prospective cohort including nulliparous women and women with preeclampsia or intrauterine growth restriction in previous pregnancy. We screened patients at 11-14 weeks of gestation to calculate the risk for preeclampsia. The primary outcome was preeclampsia and gestational age at delivery. Performance of the model was evaluated by area under the receiver operating characteristic (ROC) curves (AUCs) and calibration graphs; based on the ROC curves, optimal predicted risk cutoff values for our study population were defined. RESULTS: We analyzed 362 women, of whom 22 (6%) developed preeclampsia. The algorithm showed fair discriminative performance for preeclampsia <34 weeks (AUC 0.81; 95% CI 0.65-0.96) and moderate discriminative performance for both preeclampsia <37 weeks (AUC 0.71; 95% CI 0.51-0.90) and <42 weeks (AUC 0.71; 95% CI 0.61-0.81). Optimal cutoffs based on our study population for preeclampsia <34, <37, and <42 weeks were 1:250, 1:64, and 1:22, respectively. Calibration was poor. CONCLUSIONS: Performance of the FMF preeclampsia algorithm was satisfactory to predict early and preterm preeclampsia and less satisfactory for term preeclampsia in a high-risk population. However, by addressing some of the limitations of the present study, the performance can potentially improve. This is essential before implementation is considered

    Modelling Hospital Medical Wards to Address Patient Complexity: A Case-Based Simulation-Optimization Approach

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    In this paper we focus on patient flows inside Internal Medicine Departments, with the aim of supporting new organizational models taking into account the patient relevant characteristics such as complexity and frailty. The main contribution of this paper is to develop a Discrete Event Simulation model to describe in detail the pathways of complex patients through medical hospital wards. The model has been applied to reproduce a case study of an Italian middle size hospital. The objective is quantifying the impact on resource use and outcome of introducing a new organizational model for medical departments. The re-organization is mainly focused on changing the available beds assignment among the wards to better address the complexity of care of patients with comorbidities. Following a patient-centered approach, patients are segmented considering the clinical characteristics (i.e. the pathology, proxy of Diagnoses Related Groups classification) and sub-grouped considering other characteristics, such as comorbidities and ward of admission. Then, an optimization component embedded into the model chooses the best pooling strategy to reorganize medical wards, determining the corresponding number of beds able to improve process indicators, such as length of stay. The simulation model is presented, and preliminary results are analyzed and discussed
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