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We study the processes and mechanisms of electron-beam melting (EBM) used in the production of high-purity metals. We formulate the requirements that should be imposed on the EBM parameters for the production of high-quality materials and proposed some optimal modes. [ABSTRACT FROM AUTHOR]

The phytohormone auxin plays a vital role in almost every aspect of plant growth and development. Expression of auxin-responsive genes is controlled by a family of Auxin Response Factor (ARF) transcription factor family. This study examined the function and expression pattern of a gene encoding Auxin Response Factor B3 from Medicago truncatula (MtARF-B3) after its heterologous expression in the model plant Arabidopsis thaliana. Stable transgenic plants with ARF-B3 overexpres-sion, downregulation and transcriptional reporters were constructed. Transcriptional and histochemical assays revealed a stable MtARF-B3 expression in various stages of somatic embryogenesis and during the postembryonic development of A. thaliana. Morphological analysis and morphometric measurements confirmed the important role of MtARF-B3 in general plant growth and development, root growth and seed production. [ABSTRACT FROM AUTHOR]

Phenotypic evaluation of epigenetic mutants is mainly based on the analysis of plant growth and morphological features. However, there are cellular level changes that are not visible to the naked eye and require analysis with higher resolution techniques. In this study, we carried out a phenotypic characterisation of several Arabidopsis thaliana hypomethylation mutants by quantitative image analysis combined with flow cytometry. This phenotyping approach permitted identification of abnormalities at the cellular level in mutants with wild-type morphology at the organ level. Morphometry of adaxial leaf epidermis revealed variations in the size and number of pavement cells, and the density and distribution of stomata in the analysed second rosette leaves from the mutants studied. A direct correlation between DNA ploidy status and leaf pavement cell size in wild type and mutant leaves was observed. Recognition of hidden phenotypic variations could facilitate the identification of key genetic loci underlying the phenotypes caused by modifications of DNA methylation. Thus, this study outlines an easy and fast phenotyping strategy that can be used as a reliable tool for characterisation of epigenetic mutants at the cellular level. [ABSTRACT FROM AUTHOR]

Replacing 'happiness' with 'inflammation' in Thomas Merton's quotation holds true for the processes that govern our immune response and health. The balance between pro- and anti-inflammatory signals regulates inflammatory responses, leading to either restoration of health or the development and progression of disease, depending on whether it creates equilibrium or dysfunction. This issue of Clinical Pharmacology & Therapeutics highlights emerging research and concepts related to inflammation and its underlying role in chronic disease and variable drug response. [ABSTRACT FROM AUTHOR]

An amended quasi-stationary model of heat transfer in a metallic ingot hardening in a water-cooled crucible after electron-beam melting and refining of the metal is suggested. The processes of heat transfer and heat flows through different interfaces are considered for aluminum and tantalum under the assumption of three mechanisms of heat transfer. The model allows for the temperature dependences of the thermal conductivity and specific heat capacity. Experimental results are used for estimating the distribution of energy in beam heating of the metal and the losses of heat to radiation and evaporation from the upper surface of the ingot. Data on the shape of the hardening front, on the geometry of the molten zone, on the heat flow at various treatment parameters (electron beam power, casting rate, etc.) are obtained and discussed. [ABSTRACT FROM AUTHOR]

Plants experience a number of limiting factors, as drought and heat, which are often coinciding stress factors in natural environment. This study evaluated the changes in mesophyll cell ultrastructure in the leaves of two varieties of winter wheat (Triticum aestivum L.), differing in their drought tolerance, under individual or combined drought and heat treatment. Although the individual stress factors affected leaf ultrastructure, the damaging effect of the combined drought and heat was more pronounced and manifested certain differences between genotypes. Chloroplasts and mitochondria were affected in a variety-specific manner under all adverse treatments. The organelles of the drought-tolerant Katya were better preserved than those in the sensitive variety Sadovo. Leaf ultrastructure can be considered as one of the important characteristics in the evaluation of the drought susceptibility of different wheat varieties. [ABSTRACT FROM AUTHOR]

Recurrent drought periods of varying duration often cause extensive crop damage and affect wheat production in Southern Europe. This study compares biochemical and ultrastructural responses of four wheat ( Triticum aestivum L.) cultivars to long-term field drought, and their contribution to final grain yield. Gel electrophoresis and immunoblotting analyses combined with transmission electron microscopy and grain yield evaluation were employed to assess drought susceptibility of the wheat cultivars. Two of them behaved as drought-tolerant, the other two presented as drought sensitive. Enhanced degradation of Rubisco large subunit (RLS), Rubisco small subunit (RSS) and Rubisco activase (RA) accompanied by an increased protease activity and reduced levels of heat shock proteins (HSP70) and dehydrins (DHNs) were associated with drought sensitivity. Drought tolerance coincided with relatively stable or increased HSP70 and DHN contents, and unchanged/higher levels of RLS, RSS and RA. Sensitive cultivars were more vulnerable to ultrastructural damages, showing obvious degradation of chloroplast membrane systems and depletion of leaf starch reserves. These drought responses affected yield potential, as tolerant cultivars gave higher yield under intense drought. Thus, our results provide additional insights into the complexity of plant drought responses, identifying multiple interacting traits that may serve as indirect selection criteria for wheat drought tolerance. [ABSTRACT FROM AUTHOR]

The author reflects on inflammation and discusses if it is beneficial or harmful to human body. Inflammation occurs in response to cell or tissue damage by pathogens and plays fundamental role in the integrity of cell. He highlights inflammation as a crucial factor in the development and course of chronic diseases and current therapeutics for it and variable response of humans. He also provides the historical perspective about it, the new drugs and the clinical implications for drug disposition.

We evaluated the pre-clinical efficacy of a novel intraperitoneal (i.p.) sustained-release paclitaxel formulation (PTX(ePC)) using bioluminescent imaging (BLI) in the treatment of ovarian cancer. Human ovarian carcinoma cells stably expressing the firefly luciferase gene (SKOV3(Luc)) were injected i.p. into SCID mice. Tumour growth was evaluated during sustained or intermittent courses of i.p. treatment with paclitaxel (PTX). In vitro bioluminescence strongly correlated with cell survival and cytotoxicity. Bioluminescent imaging detected tumours before their macroscopic appearance and strongly correlated with tumour weight and survival. As compared with intermittent therapy with Taxol, sustained PTX(ePC) therapy resulted in significant reduction of tumour proliferation, weight and BLI signal intensity, enhanced apoptosis and increased survival times. Our results demonstrate that BLI is a useful tool in the pre-clinical evaluation of therapeutic interventions for ovarian cancer. Moreover, these results provide evidence of enhanced therapeutic efficacy with the sustained PTX(ePC) implant system, which could potentially translate into successful clinical outcomes. [ABSTRACT FROM AUTHOR]

Two important enzyme in organic acid metabolism, phosphoenolpyruvate carboxylase (PEPC) and NADP-malic enzyme (NADP-ME), show marked diurnal rhythms in their activities during the establishment of the soybean - B. japonicum symbiosis. The pH of the nutrient solution changes in parallel with NADP-ME activity, being maximal during the night periods, whereas activity of PEPC was highest during the day periods. The results from the experiments with stem girdled plants indicated that the activity of root PEPC is modulated to a great extent by the supply of photosynthates from the shoots. It was also established that succinate application in the nutrient solution during inoculation altered significantly the pattern of assayed enzyme activities. Although our experiments did not reveal the precise mechanism of the involvement of root PEPC and NADP-ME in soybean response to inoculation with B. japonicum, they indicated the pattern of their activity during the first 72 h postinoculation which are critical for establishment and functioning of the symbiosis. [ABSTRACT FROM AUTHOR]

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Mutagenesis provoked by exposure to increased concentration of antibiotics of five indigenous Rhizobium galegae strains resulted in the generation of several antibiotic-resistant mutants. The mutants differed from the wild type and one from another in respect to the nodulation capacity, the nitrogenase activity, the nodule ultrastructure, and the plant growth response. Galega plants inoculated with mutants resistant to streptomycin and rifampicin formed nodules with higher nitrogenase activity and accumulated more shoot dry biomass than plants inoculated with the parent strains. Resistance to kanamycin and nalidixic acid was associated with significant decrease of nitrogenase activity. A correlation between nitrogen-fixing efficiency and nodule infected cell ultrastructure was found. When the bacteroids occupied about 10 times higher area in infected cells of nodule than peribacteroid spaces and host cytosol had electron dense and homogenous structure, the nitrogenase activity was the highest. [ABSTRACT FROM AUTHOR]

An abstract of the conference paper "Cutaneous polyarteriitis nodosa with Grave's disease and cholestatic liver disease," by V. Vassileva and B. Varbanova is presented.

Background: While ovarian tumors initially appear responsive to chemotherapy, most patients relapse with drug resistant disease. We hypothesized that sustained, local delivery of paclitaxel (PTX) could impact chemo-responsiveness of ovarian tumors by controlling the expression of P-glycoprotein (Pgp)/MDR1.Methods: Sustained and intermittent administration of PTX using free-PTX or a novel sustained PTX implant system was examined in vitro in SKOV-3 cells and in vivo in an intraperitoneal human ovarian xenograft murine model implanted ip with the sustained release formulation. MDR1/Pgp expression was examined by RT-PCR, flow cytometry and immunohistochemistry.Results: Equivalent dosing of free-PTX by either sustained or intermittent treatments (5-250 ng/ml) induced MDR1 mRNA levels by 3-4 fold in SKOV-3 cells (P<0.05) without altering Pgp protein levels. On the other hand, similar treatments with PTX-implants did not induce MDR1 or Pgp expression in vitro. Likewise, we did not detect significant changes in the in vivo expression of MDR1/Pgp in xenografts obtained from mice treated for 14 days with sustained PTX-implants which delivered doses of 2.4-240 mg/kg/day of PTX. Basal MDR1/Pgp levels were seen in the highest treatment group.Conclusions: Overall, localized and sustained administration of PTX does not aggravate MDR1 development thereby demonstrating potential as a novel treatment strategy for ovarian cancer.Clinical Pharmacology & Therapeutics (2005) 79, P11–P11; doi: 10.1016/j.clpt.2005.12.039 [ABSTRACT FROM AUTHOR]

Plants of goat's rue (Galega orientalis) inoculated with Rhizobium galegae strain HAMBI 540 were grown in the presence of putrescine (Put), spermidine (Spd) or spermine (Spm), and several symbiotic characteristics were investigated to delineate the influence of polyamines (PA) on this nitrogen-fixing system. All three PA exerted a concentration-dependent effect on the nodule parameters tested. The increment ofnodulation ability and nodule biomass accumulation was extreme (from2.4- to 4.0-fold) when plants were subjected to 10 and 50 muM of various PA. However, at 100 muM a negative effect was observed. The acetylene-reduction activity of nodulated roots was increased also in response to treatment with the lower PA concentrations. The level of nitrogenase activity supported by succinate was significantly higher in bacteroids isolated from PA-treated nodules than in bacteroids from control nodules. The symbiotic parameters were also dependent on the type of PA used; the most effective being the diamine Put, while Spm showed a smaller physiological effect with respect to the others. Polyamines altered the ultrastructure of Galega nodule infected cells. After treatment with these substances, pronounced changes in the relative volume of the main components of infected cells and their compartments were observed. The significance of the structural observations and morphometric analyses, their relationship to differences in nitrogen fixation and possible modes of action are discussed. [ABSTRACT FROM AUTHOR]