Hepatogenic differentiation of human mesenchymal stem cells from adipose tissue :

制度:新 ; 報告番号:乙2169号 ; 学位の種類:博士(理学) ; 授与年月日:2008/6/19 ; 早大学位記番号:新483

Solvability of a Volterra–Stieltjes integral equation in the class of functions having limits at infinity

The paper is devoted to the study of the solvability of a nonlinear Volterra–Stieltjes integral equation in the class of real functions defined, bounded and continuous on the real half-axis $\mathbb{R}_+$ and having finite limits at infinity. The considered class of integral equations contains, as special cases, a few types of nonlinear integral equations. In particular, that class contains the Volterra–Hammerstein integral equation and the Volterra–Wiener–Hopf integral equation, among others. The basic tools applied in our study is the classical Schauder fixed point principle and a suitable criterion for relative compactness in the Banach space of real functions defined, bounded and continuous on $\mathbb{R}_+$. Moreover, we will utilize some facts and results from the theory of functions of bounded variation

The upregulation of thiamine (vitamin B1) biosynthesis in Arabidopsis thaliana seedlings under salt and osmotic stress conditions is mediated by abscisic acid at the early stages of this stress response

<p>Abstract</p> <p>Background</p> <p>Recent reports suggest that vitamin B₁(thiamine) participates in the processes underlying plant adaptations to certain types of abiotic and biotic stress, mainly oxidative stress. Most of the genes coding for enzymes involved in thiamine biosynthesis in <it>Arabidopsis thaliana </it>have been identified. In our present study, we examined the expression of thiamine biosynthetic genes, of genes encoding thiamine diphosphate-dependent enzymes and the levels of thiamine compounds during the early (sensing) and late (adaptation) responses of Arabidopsis seedlings to oxidative, salinity and osmotic stress. The possible roles of plant hormones in the regulation of the thiamine contribution to stress responses were also explored.</p> <p>Results</p> <p>The expression of Arabidopsis genes involved in the thiamine diphosphate biosynthesis pathway, including that of <it>THI1</it>, <it>THIC</it>, <it>TH1 </it>and <it>TPK</it>, was analyzed for 48 h in seedlings subjected to NaCl or sorbitol treatment. These genes were found to be predominantly up-regulated in the early phase (2-6 h) of the stress response. The changes in these gene transcript levels were further found to correlate with increases in thiamine and its diphosphate ester content in seedlings, as well as with the enhancement of gene expression for enzymes which require thiamine diphosphate as a cofactor, mainly α-ketoglutarate dehydrogenase, pyruvate dehydrogenase and transketolase. In the case of the phytohormones including the salicylic, jasmonic and abscisic acids which are known to be involved in plant stress responses, only abscisic acid was found to significantly influence the expression of thiamine biosynthetic genes, the thiamine diphosphate levels, as well as the expression of genes coding for main thiamine diphosphate-dependent enzymes. Using Arabidopsis mutant plants defective in abscisic acid production, we demonstrate that this phytohormone is important in the regulation of <it>THI1 </it>and <it>THIC </it>gene expression during salt stress but that the regulatory mechanisms underlying the osmotic stress response are more complex.</p> <p>Conclusions</p> <p>On the basis of the obtained results and earlier reported data, a general model is proposed for the involvement of the biosynthesis of thiamine compounds and thiamine diphosphate-dependent enzymes in abiotic stress sensing and adaptation processes in plants. A possible regulatory role of abscisic acid in the stress sensing phase is also suggested by these data.</p

Response to commentary “Zinc is decreased in prostate cancer: an established relationship of prostate cancer!”

10.1007/s00775-010-0737-8Journal of Biological Inorganic Chemistry1619-13JJBC

Cytosolic superoxide dismutase activity after photodynamic therapy, intracellular distribution of Photofrin II and hypericin, and P-glycoprotein localization in human colon adenocarcinoma.

In photodynamic therapy (PDT), a tumor-selective photosensitizer is administered and then activated by exposure to a light source of applicable wavelength. Multidrug resistance (MDR) is largely caused by the efflux of therapeutics from the tumor cell by means of P-glycoprotein (P-gp), resulting in reduced efficacy of the anticancer therapy. This study deals with photodynamic therapy with Photofrin II (Ph II) and hypericin (Hyp) on sensitive and doxorubicin-resistant colon cancer cell lines. Changes in cytosolic superoxide dismutase (SOD1) activity after PDT and the intracellular accumulation of photosensitizers in sensitive and resistant colon cancer cell lines were examined. The photosensitizers' distributions indicate that Ph II could be a potential substrate for P-gp, in contrast to Hyp. We observed an increase in SOD1 activity after PDT for both photosensitizing agents. The changes in SOD1 activity show that photodynamic action generates oxidative stress in the treated cells. P-gp appears to play a role in the intracellular accumulation of Ph II. Therefore the efficacy of PDT on multidrug-resistant cells depends on the affinity of P-gp to the photosensitizer used. The weaker accumulation of photosensitizing agents enhances the antioxidant response, and this could influence the efficacy of PDT

Silicon-based photonic crystals fabricated using proton beam writing combined with electrochemical etching method

A method for fabrication of three-dimensional (3D) silicon nanostructures based on selective formation of porous silicon using ion beam irradiation of bulk p-type silicon followed by electrochemical etching is shown. It opens a route towards the fabrication of two-dimensional (2D) and 3D silicon-based photonic crystals with high flexibility and industrial compatibility. In this work, we present the fabrication of 2D photonic lattice and photonic slab structures and propose a process for the fabrication of 3D woodpile photonic crystals based on this approach. Simulated results of photonic band structures for the fabricated 2D photonic crystals show the presence of TE or TM gap in mid-infrared rang

Risk factors for major leg amputation in patients treated endovascularly due to critical limb ischaemia

Introduction. Critical limb ischaemia (CLI) is an advanced phase of chronic lower extremity ischaemia linked to increased mortality, decreased quality of life, and the risk of leg amputation. The aim of this study was to determine factors affecting the risk of leg amputation among patients with CLI treated endovascularly as a first approach. Material and methods. Of 118 patients treated endovascularly, 32 (27%) had a leg amputated. Their clinical data were analysed retrospectively. Results. Patients who had a leg amputated initially had a higher Rutherford class, were older, and had a greater prevalence of comorbidities. In multivariate analysis, amputation-free survival was shortened by a history of dyslipidaemia, female gender, blood creatinine concentration, the need for target lesion revascularization, smoking habit, Rutherford class, and leukocyte blood count. Whereas, the factors which decreased the risk of leg amputation were: use of statins, the number of previous interventions, and blood LDL cholesterol concentration. Angiographic classification of lesion severity did not affect endovascular procedure outcome. Conclusions. The risk of major amputation following endovascular treatment in patients with CLI was associated with a number of characteristics, mainly: atherosclerosis risk factors and necrosis advancement, and the number of reinterventions. To avoid endangering patients and the unnecessary utilization of resources, it would seem to be worth performing large studies to determine a risk stratification scoring system for patients with CLI, which could enable the qualification of risk-adjusted patients for endovascular or surgical revascularization or for primary leg amputation.

The importance and direction of current and future plant-UV research : break-out session discussions at the UV4Plants Network Meeting in Bled (April 15th -18th , 2018)

During the 2nd Network Meeting of UV4Plants at Bled (14th–18th April, 2018) the delegates engaged in a group discussion of prescient questions concerning the future of in plant-UV research. The discussion group was tasked to identify the most valuable directions for plant UV research to take, and to create a coherent framework for how to move the field forward. Here, the outcome of these discussions is summarised in sections that follow the composition of discussion groups as ideas taken from a molecular, biochemical and physiological perspective followed by those from an ecological and plant production perspective. In each case, first basic research questions are considered and then applications and methodological considerations are put forward. Finally, some common ground bringing the two perspectives together is discussed, with the aim of solving scaling problems and ways in which the UV4Plants network might be put to good use.Peer reviewe

A perspective on ecologically relevant plant-UV research and its practical application

Plants perceive ultraviolet-B (UV-B) radiation through the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8), and initiate regulatory responses via associated signalling networks, gene expression and metabolic pathways. Various regulatory adaptations to UV-B radiation enable plants to harvest information about fluctuations in UV-B irradiance and spectral composition in natural environments, and to defend themselves against UV-B exposure. Given that UVR8 is present across plant organs and tissues, knowledge of the systemic signalling involved in its activation and function throughout the plant is important for understanding the context of specific responses. Fine-scale understanding of both UV-B irradiance and perception within tissues and cells requires improved application of knowledge about UV-attenuation in leaves and canopies, warranting greater consideration when designing experiments. In this context, reciprocal crosstalk among photoreceptor-induced pathways also needs to be considered, as this appears to produce particularly complex patterns of physiological and morphological response. Through crosstalk, plant responses to UV-B radiation go beyond simply UV-protection or amelioration of damage, but may give cross-protection over a suite of environmental stressors. Overall, there is emerging knowledge showing how information captured by UVR8 is used to regulate molecular and physiological processes, although understanding of upscaling to higher levels of organisation, i.e. organisms, canopies and communities remains poor. Achieving this will require further studies using model plant species beyond Arabidopsis, and that represent a broad range of functional types. More attention should also be given to plants in natural environments in all their complexity, as such studies are needed to acquire an improved understanding of the impact of climate change in the context of plant-UV responses. Furthermore, broadening the scope of experiments into the regulation of plant-UV responses will facilitate the application of UV radiation in commercial plant production. By considering the progress made in plant-UV research, this perspective highlights prescient topics in plant-UV photobiology where future research efforts can profitably be focussed. This perspective also emphasises burgeoning interdisciplinary links that will assist in understanding of UV-B effects across organisational scales and gaps in knowledge that need to be filled so as to achieve an integrated vision of plant responses to UV-radiation.Peer reviewe