Study of oxidation by chemiluminescence. IV. Detection of low levels of lipid hydroperoxides by chemiluminescence

Sodium hypochlorite (NaOCl) induced decomposition of organic hydroperoxides gave strong chemiluminescence. Chemiluminescence intensity reached its maximum a few seconds after the addition of sodium hypochlorite and decreased to the background level in three min. Good linear relationships were observed between total chemiluminescence counts in three min and the amounts of hydroperoxides. This chemiluminescence method can be applied to the detection of low levels of lipid hydroperoxides.     

Overproduction and purification of the regulatory subunit of Escherichia coli aspartate transcarbamoylase

An Escherichia coli strain/plasmid system has been developedfor the overexpression of the regulatory subunit of E.coli aspartatetranscarbamoylase (ATCase). Production of large quantities ofregulatory subunit, by the method described here, should facilitatefuture experiments, such as X-ray crystallography, NMR and hybridizationexperiments, aimed at understanding the heterotropic mechanismthat regulates the activity of ATCase. The plasmid used forthe over-expression carries the gene for the regulatory subunit,pyrI, downstream from the strong pyrB promoter. The host strain,EK1104 [Nowlan, S.F. and Kantrowitz, E.R. (1985) J. Biol. Chem.,260, 14712–14716] carries a deletion in the pyrBI regionof the chromosome, as well as a leaky pyrF allele. When thisstrain/plasmid system is grown under limiting pyrimidine levels,large quantities of the regulatory subunit of ATCase are producedwithout any trace of catalytic subunit or holo-enzyme. A procedurefor the purification of the regulatory subunit from cell extractshas also been developed yielding {small tilde}50 mg of purifiedregulatory subunit per liter of initial culture. The regulatorysubunit produced in this fashion is fully competent in reassociationexperiments with the native catalytic subunit. Furthermore,the reassociated holoenzyme exhibits kinetic properties identicalto those of the wild type enzyme. In addition, we report theconstruction of a pUC119 based plasmid which carries a uniqueNdeI site at the fMet of the pyrB gene of ATCase. This plasmid,which was used in the construction of the system for the overexpressionof the regulatory subunit of ATCase, has been shown to be ofgeneral use for the expression of foreign proteins in E.coli.     

Activation of Notch3 in Renal Tubular Cells Leads to Progressive Cystic Kidney Disease

Background: Polycystic kidney disease (PKD) is a genetic disorder affecting millions of people worldwide that is characterized by fluid-filled cysts and leads to end-stage renal disease (ESRD). The hallmarks of PKD are proliferation and dedifferentiation of tubular epithelial cells, cellular processes known to be regulated by Notch signaling. Methods: We found increased Notch3 expression in human PKD and renal cell carcinoma biopsies. To obtain insight into the underlying mechanisms and the functional consequences of this abnormal expression, we developed a transgenic mouse model with conditional overexpression of the intracellular Notch3 (ICN3) domain specifically in renal tubules. We evaluated the alterations in renal function (creatininemia, BUN) and structure (cysts, fibrosis, inflammation) and measured the expression of several genes involved in Notch signaling and the mechanisms of inflammation, proliferation, dedifferentiation, fibrosis, injury, apoptosis and regeneration. Results: After one month of ICN3 overexpression, kidneys were larger with tubules grossly enlarged in diameter, with cell hypertrophy and hyperplasia, exclusively in the outer stripe of the outer medulla. After three months, mice developed numerous cysts in proximal and distal tubules. The cysts had variable sizes and were lined with a single- or multilayered, flattened, cuboid or columnar epithelium. This resulted in epithelial hyperplasia, which was observed as protrusions into the cystic lumen in some of the renal cysts. The pre-cystic and cystic epithelium showed increased expression of cytoskeletal filaments and markers of epithelial injury and dedifferentiation. Additionally, the epithelium showed increased proliferation with an aberrant orientation of the mitotic spindle. These phenotypic tubular alterations led to progressive interstitial inflammation and fibrosis. Conclusions: In summary, Notch3 signaling promoted tubular cell proliferation, the alignment of cell division, dedifferentiation and hyperplasia, leading to cystic kidney diseases and pre-neoplastic lesions.     

Vascular endothelial growth factor: An important molecular target of curcumin

The discovery of Vascular Endothelial Growth Factor (VEGF), the key modulator of angiogenesis, has triggered intensive research on anti-angiogenic therapeutic modalities. Although several clinical studies have validated anti-VEGF therapeutics, with few of them approved by the U.S. Food and Drug Administration (FDA), anti-angiogenic therapy is still in its infancy. Phytochemicals are compounds that have several metabolic and health benefits. Curcumin, the yellow pigment derived from turmeric (Curcuma longa L.) rhizomes, has a wide range of pharmaceutical properties. It has also been shown to inhibit VEGF by several studies. In this review, we elaborate the effect of curcumin on VEGF and angiogenesis and its therapeutic application.     

A community of practice view of intervention programmes: the case of women returning to IT

The study presents an intervention programme for women returning to the information technology (IT) industry following a career break. This is interpreted through the lens of the community of practice perspective. The longitudinal nature of the case study offered opportunities for in‐depth investigation of participants' experience and development during the process. Using this datum, a mid‐level analytical approach is adopted. It is found that learning about the path to return to IT emerged regardless of the degree of participation in the intervention programme, and this was supported by the diversity and integration embedded in this programme. The implications of the findings for our understanding of intervention programmes are discussed.     

Large grain Cu(In,Ga)Se2 thin film growth using a Se-radical beam source

Cu(In,Ga)Se₂ (CIGS) thin films were grown by the three-stage process using a rf-plasma cracked Se-radical beam source. CuGaSe₂ (CGS) films grown at a maximum substrate temperature of 550 °C and CuInSe₂ (CIS) and CIGS films grown at the lower temperature of 400 °C exhibited highly dense surfaces and large grain size compared with films grown using a conventional Se-evaporative source. This result is attributed to the modification of the growth kinetics due to the presence of active Se-radical species and enhanced surface migration during growth. The effect on CIGS film properties and solar cell performance has been investigated. Enhancements in the cell efficiencies of 400 °C-grown CIS and CIGS solar cells have been demonstrated using a Se-radical source.     

Sustainable energy planning by using multi-criteria analysis application in the island of Crete

The sustainable energy planning includes a variety of objectives, as the decision-making is directly related to the processes of analysis and management of different types of information (technological, environmental, economic and social). Very often, the traditional evaluation methods, such as the cost-benefit analysis and macro-economic indicators, are not sufficient to integrate all the elements included in an environmentally thorough energy plan. On the contrary the multiple criteria methods provide a tool, which is more appropriate to assemble and to handle a wide range of variables that is evaluated in different ways and thus offer valid decision support.     

Isolation of heterothallic haploid and auxotrophic mutants of Schizosaccharomyces japonicus

The fission yeast Schizosaccharomyces japonicus var. japonicus belong to the genus Schizosaccharomyces, together with Schizosaccharomyces pombe, which has been well studied as a model organism. In contrast, Sz. japonicus is poorly characterized and genetic tools were yet to be developed. We here report the isolation of the heterothallic haploids NIG2017, NIG2025 and NIG2028, which were derivatives of a Sz. japonicus homothallic strain (NIG2008). Based on the genomic sequence of Sz. japonicus, released by the Broad Institute, we found that Sz. japonicus also possesses orthologues of the mating‐type genes of Sz. pombe; two mat‐M (?) and two mat‐P (+) genes. As expected, heterothallic strains were defective in one of the Sz. japonicus mat genes (mat^sj). We confirmed that NIG2017 and NIG2025 strains only expressed mRNA from the mat^sj‐P genes, while homothallic strains expressed both mat^sj‐M and mat^sj‐P. Although the NIG2028 strain expressed both gene products, mat^sj‐P was found mutated, which may have conferred the heterothallic phenotype of the mutant. Thus, we concluded that these were stable heterothallic strains. We designated NIG2017 and NIG2025 as h⁺ and NIG 2028 as h^?, respectively. We also found additional h^? strains (NIG5872 and NIG5873) that arose from the cross between NIG2017 and NIG2028 derivatives. In addition to that, we have constructed a ura4^sj‐deleted strain and an ade6^sj‐mutated strain. We used these heterothallic strains and the auxotroph strains to perform spore dissection analysis to determine the genetic distances between several loci, and found that the mating type loci and ade6^sj locus were linked to centromeres. Copyright © 2009 John Wiley & Sons, Ltd.     

Theoretical study of van der Waals dispersion force between macroscopic bodies with a periodic material distribution

A method has been developed for calculating the van der Waals dispersion force between a macroscopic body consisting of a uniform material and a macroscopic body with a spatially periodic material distribution. The periodic material distribution is one dimensional in the x-direction. The periodically distributed material property function is expanded as a Fourier series. The van der Waals forces for a distribution of two materials were then calculated as a typical example of a periodic material distribution. The effects of parameters such as the duty ratio of the material distribution, the refractive index ratio of the two materials, and the length of the uniform body on the van der Waals force were shown.