136 research outputs found

    Photophysics of the electronic states S0 and S1 for the coplanar molecular structures of the α,ω-diphenylpolyenes DPH and DPO

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    Spectroscopy of the monoclinic and orthorhombic crystalline forms of all-trans-diphenylhexatriene (DPH) and all-trans-diphenyloctatetraene (DPO) show absorption and emission bands that do not generate the widely known Stokes shift of the polyene compounds, discovered by Hausser et al. in 1953 and repeatedly studied over the last 60 years. It can be concluded from our study that the crystallization system, whether in a monoclinic or orthorhombic system, does not significantly influence the photophysics of DPH and DPO in the crystal phas

    Clara cell adhesion and migration to extracellular matrix

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    <p>Abstract</p> <p>Background</p> <p>Clara cells are the epithelial progenitor cell of the small airways, a location known to be important in many lung disorders. Although migration of alveolar type II and bronchiolar ciliated epithelial cells has been examined, the migratory response of Clara cells has received little attention.</p> <p>Methods</p> <p>Using a modification of existing procedures for Clara cell isolation, we examined mouse Clara cells and a mouse Clara-like cell line (C22) for adhesion to and migration toward matrix substrate gradients, to establish the nature and integrin dependence of migration in Clara cells.</p> <p>Results</p> <p>We observed that Clara cells adhere preferentially to fibronectin (Fn) and type I collagen (Col I) similar to previous reports. Migration of Clara cells can be directed by a fixed gradient of matrix substrates (haptotaxis). Migration of the C22 cell line was similar to the Clara cells so integrin dependence of migration was evaluated with this cell line. As determined by competition with an RGD containing-peptide, migration of C22 cells toward Fn and laminin (Lm) 511 (formerly laminin 10) was significantly RGD integrin dependent, but migration toward Col I was RGD integrin independent, suggesting that Clara cells utilize different receptors for these different matrices.</p> <p>Conclusion</p> <p>Thus, Clara cells resemble alveolar type II and bronchiolar ciliated epithelial cells by showing integrin mediated pro-migratory changes to extracellular matrix components that are present in tissues after injury.</p

    Human Epididymis Secretory Protein 4 (HE4) Compromises Cytotoxic Mononuclear Cells via Inducing Dual Specificity Phosphatase 6

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    While selective overexpression of serum clinical biomarker Human epididymis secretory protein 4 (HE4) is indicative of ovarian cancer tumorigenesis, much is still known about the mechanistic role of the HE4 gene or gene product. Here, we examine the role of the secretory glycoprotein HE4 in ovarian cancer immune evasion. Through modified subtractive hybridization analyses of human peripheral blood mononuclear cells (PBMCs), we have characterized gene targets of HE4 and established a preliminary mechanism of HE4-mediated immune failure in ovarian tumors. Dual specificity phosphatase 6 (DUSP6) emerged as the most upregulated gene in PBMCs upon in vitro exposure to HE4. DUSP6 was found to be upregulated in CD8+ cells and CD56+ cells. HE4 exposure reduced Erk1/2 phosphorylation specifically in these cell populations and the effect was erased by co-incubation with a DUSP6 inhibitor, (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one (BCI). In co-culture with PBMCs, HE4-silenced SKOV3 human ovarian cancer cells exhibited enhanced proliferation upon exposure to external HE4, while this effect was partially attenuated by adding BCI to the culture. Additionally, the reversal effects of BCI were erased in the co-culture with CD8+ / CD56+ cell deprived PBMCs. Taken together, these findings show that HE4 enhances tumorigenesis of ovarian cancer by compromising cytotoxic CD8+ and CD56+ cells through upregulation of self-produced DUSP6

    Nothing New in the (North) East? Interpreting the Rhetoric and Reality of Japanese Corporate Governance

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    Japan finally seems to be pulling itself out of its lost decade (and a half) of economic stagnation. Some grudgingly or triumphantly attribute this to micro-economic reforms, freeing up arthritic markets, although there is also evidence that macro-economic policy failures have been a major cause of poor performance since the 1990s. Many point to overlapping transformations in corporate governance, broadly defined to cover relationships among managers and employees as well as between firms and outside shareholders, creditors, and other stakeholders. These relationships are in flux, with moves arguably favouring shareholders and more market-driven control mechanisms. It has certainly been a found decade for law reform in Japan, particularly in corporate law, with a plethora of legislative amendments commencing around 1993 and culminating in the enactment of a consolidated Company Law in 2005. This modernisation project, particularly since 2001, is reportedly aimed at (i) securing better corporate governance, (ii) bringing the law into line with a highly-developed information society, (iii) liberalising fundraising measures, (iv) bringing corporate law into line with the internationalization of corporate activity, and (v) modernizing terms and consolidating corporate law. Because the suite of revisions has moved away from strict mandatory rules set out originally in Japan\u27s Commercial Code of 1899, modeled primarily on German law, another growing perception is that Japanese corporate law and practice is or will soon be converging significantly on US models. However, assessments remain divided as to whether these moves in corporate governance and capitalism more generally in Japan amount to a new paradigm or regime shift . Focusing primarily on quite influential commentary in English, Part I of this paper outlines two pairs of views. It concludes that the most plausible assessment is of significant but gradual transformation towards a more market-driven approach, evident also in other advanced political economies. Drawing more generally from these often virulently divided views, Part II sets out five ways forward through the proliferating literature and source material on corporate governance in Japan. Particular care must be taken in: (i) selecting the temporal timeframe, (ii) selecting countries to compare, (iii) balancing black-letter law and broader socio-economic context, (iv) reflecting on and disclosing normative preferences, and (v) giving weight to processes as well as outcomes, when assessing change in Japan - and any other country\u27s governance system. Part III ends with a call for further research particularly on law- and policy-producing processes, rather than mainly outcomes. It also outlines the usefulness of this analytical framework for analysing the broader field of Corporate Social Responsibility, now emerging as the next major area of debate and transformation in Japan - as elsewhere

    Nothing New in the (North) East? Interpreting the Rhetoric and Reality of Japanese Corporate Governance

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    Evidence for the presence of an endogenous inhibitor of prolyl hydroxylase

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    Prolyl hydroxylase [EC 1.14.11.2] was shown to be inhibited by an ultrafiltrate (less than 30,000 molecular weight) fraction isolated from skin and blood of neonatal and adult rabbits. This fraction also inhibited two other α-ketoglutarate requiring mixed function oxidases, lysyl hydroxylase [EC 1.14.11.4] and α-butyrobetaine hydroxylase [EC 1.14.11.1] but not the amine oxidase, lysyl oxidase. Purification of the skin ultrafiltrate on Sephadex G-25 demonstrated a peak of prolyl hydroxylase inhibitory activity which chromatographed at a molecular weight corresponding to approximately 3,000. Chromatography of a blood ultrafiltrate separated a similar peak of material which was inhibitory for prolyl hydroxylase

    Metabolism and nutritional significance of carotenoids.

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    PHOTODYNAMIC RESPONSES IN RHODOTORULA GLUTINIS IN THE ABSENCE OF ADDED SENSITIZERS

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    Abstract— –The lethal effect of a continuous spectrum of light at wavelengths longer than 300 nm has been examined for the yeast Rhodotorula glutinis. A survival curve consisting of a shoulder, an exponential phase of death, and a “tailing off” phase was shown to occur when cells were irradiated in the absence of a sensitizing dye. An action spectrum showed that the portion of the light used for irradiation which is lethal to the cells lies between 310 and 430 nm. It was found that carotenoid pigments were not able to provide any protection against this endogenously photosensitized oxidation. Exponentially growing cells were the most sensitive to killing and, as cells approached and entered into the stationary phase of growth, they became more resistant until a constant level of sensitivity was reached. A primary temperature effect on the length of the shoulder prior to the death of the cell has been observed. The sensitivity was greatest at low temperatures with an optimum resistance occurring at 22.5°C and an increasing sensitivity occurring at higher temperatures. Various sites have been examined for cellular damage which might lead to the death of the cell. Damage was found to impair the function of the plasma‐lemma, the glycolytic and respiratory system, the nucleus, and to be observable cytologically. Copyright © 1971, Wiley Blackwell. All rights reserve
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