A red/far-red light-responsive bi-stable toggle switch to control gene expression in mammalian cells

Growth and differentiation of multicellular systems is orchestrated by spatially restricted gene expression programs in specialized subpopulations. The targeted manipulation of such processes by synthetic tools with high-spatiotemporal resolution could, therefore, enable a deepened understanding of developmental processes and open new opportunities in tissue engineering. Here, we describe the first red/far-red light-triggered gene switch for mammalian cells for achieving gene expression control in time and space. We show that the system can reversibly be toggled between stable on- and off-states using short light pulses at 660 or 740 nm. Red light-induced gene expression was shown to correlate with the applied photon number and was compatible with different mammalian cell lines, including human primary cells. The light-induced expression kinetics were quantitatively analyzed by a mathematical model. We apply the system for the spatially controlled engineering of angiogenesis in chicken embryos. The system's performance combined with cell- and tissue-compatible regulating red light will enable unprecedented spatiotemporally controlled molecular interventions in mammalian cells, tissues and organism

Beta defensin-2 is reduced in central but not in distal airways of smoker COPD patients

Background: Altered pulmonary defenses in chronic obstructive pulmonary disease (COPD) may promote distal airways bacterial colonization. The expression/activation of Toll Like receptors (TLR) and beta 2 defensin (HBD2) release by epithelial cells crucially affect pulmonary defence mechanisms. Methods: The epithelial expression of TLR4 and of HBD2 was assessed in surgical specimens from current smokers COPD (s-COPD; n = 17), ex-smokers COPD (ex-s-COPD; n = 8), smokers without COPD (S; n = 12), and from non-smoker non-COPD subjects (C; n = 13). Results: In distal airways, s-COPD highly expressed TLR4 and HBD2. In central airways, S and s-COPD showed increased TLR4 expression. Lower HBD2 expression was observed in central airways of s-COPD when compared to S and to ex-s-COPD. s-COPD had a reduced HBD2 gene expression as demonstrated by real-time PCR on micro-dissected bronchial epithelial cells. Furthermore, HBD2 expression positively correlated with FEV1/FVC ratio and inversely correlated with the cigarette smoke exposure. In a bronchial epithelial cell line (16 HBE) IL-1β significantly induced the HBD2 mRNA expression and cigarette smoke extracts significantly counteracted this IL-1 mediated effect reducing both the activation of NFkB pathway and the interaction between NFkB and HBD2 promoter. Conclusions: This study provides new insights on the possible mechanisms involved in the alteration of innate immunity mechanisms in COPD. © 2012 Pace et al

Growth Rate Responses of Missouri and Lower Yellowstone River Fishes to a Latitudinal Gradient

Notropis atherinoides, freshwater drums Aplodinotus grunniens, river carpsuckers Carpiodes carpio and saugers Stizostedion canadense collected in 1996-1998 from nine river sections of the Missouri and lower Yellowstone rivers at two life-stages (young-of-the-year and age 1+ years) were significantly different among sections. However, they showed no river-wide latitudinal trend except for age 1+ years emerald shiners that did show a weak negative relation between growth and both latitude and length of growing season. The results suggest growth rates of fishes along the Missouri River system are complex and could be of significance in the management and conservation of fish communities in this altered system

Winter Ecology of Kokanee: Implications for Salmon Management

We sampled various limnological parameters and measured growth and diet of age-0 kokanee Oncorhynchus nerka (lacustrine sockeye salmon) during two winters in a high-mountain lake of the Sawtooth Valley, Idaho. Although winter has been recognized as an important period for many warmwater fishes and for stream-dwelling salmonids, winter limitations have only recently been studied for coolwater and coldwater species. Ice and snow cover in winter limited light penetration. As a result, chlorophyll-a and zooplankton density were lower in ice-covered periods than during ice-free periods. The weight of stomach contents was often below a maintenance ration, yet the incidence of empty stomachs was extremely low (1 of 63) and the weight of stomach contents increased as energy reserves declined, indicating that kokanee were actively foraging during winter. Kokanee length and weight remained constant during the winter of 1993–1994 but increased from November through May in 1994–1995. Condition factors, however, declined significantly over the winter in both years, and lipid content approached levels associated with mortality. Differences in growth patterns may have been caused by a combination of changes in zooplankton density and kokanee abundance and in kokanee behavior to defend energy reserves or avoid predation. Results demonstrated the ambiguity of some growth measurements and the importance of choosing the correct metric for measuring growth in fishes. Because juvenile kokanee and sockeye salmon are ecologically similar, management efforts to restore the endangered Snake River sockeye salmon to the Sawtooth Valley lakes should recognize that winter conditions might be a bottleneck for this species

Clinical, physiologic, and radiographic factors contributing to development of hypoxemia in moderate to severe COPD:a cohort study

Background: Hypoxemia is a major complication of COPD and is a strong predictor of mortality. We previously identified independent risk factors for the presence of resting hypoxemia in the COPDGene cohort. However, little is known about characteristics that predict onset of resting hypoxemia in patients who are normoxic at baseline. We hypothesized that a combination of clinical, physiologic, and radiographic characteristics would predict development of resting hypoxemia after 5-years of follow-up in participants with moderate to severe COPD Methods: We analyzed 678 participants with moderate-to-severe COPD recruited into the COPDGene cohort who completed baseline and 5-year follow-up visits and who were normoxic by pulse oximetry at baseline. Development of resting hypoxemia was defined as an oxygen saturation ≤88% on ambient air at rest during follow-up. Demographic and clinical characteristics, lung function, and radiographic indices were analyzed with logistic regression models to identify predictors of the development of hypoxemia. Results: Forty-six participants (7%) developed resting hypoxemia at follow-up. Enrollment at Denver (OR 8.30, 95%CI 3.05–22.6), lower baseline oxygen saturation (OR 0.70, 95%CI 0.58–0.85), self-reported heart failure (OR 6.92, 95%CI 1.56–30.6), pulmonary artery (PA) enlargement on computed tomography (OR 2.81, 95%CI 1.17–6.74), and prior severe COPD exacerbation (OR 3.31, 95%CI 1.38–7.90) were independently associated with development of resting hypoxemia. Participants who developed hypoxemia had greater decline in 6-min walk distance and greater 5-year decline in quality of life compared to those who remained normoxic at follow-up. Conclusions: Development of clinically significant hypoxemia over a 5-year span is associated with comorbid heart failure, PA enlargement and severe COPD exacerbation. Further studies are needed to determine if treatments targeting these factors can prevent new onset hypoxemia. Trial registration COPDGene is registered at ClinicalTrials.gov: NCT00608764 (Registration Date: January 28, 2008) Electronic supplementary material The online version of this article (doi:10.1186/s12890-016-0331-0) contains supplementary material, which is available to authorized users

Energies a la mesure des villages: l'instauration d'energies renouvables das les villages africains

Bibliothek Weltwirtschaft Kiel C 142673 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman