Hypoxia significantly reduces aminolaevulinic acid-induced protoporphyrin IX synthesis in EMT6 cells

We have studied the effects of hypoxia on aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) synthesis in EMT6 monolayer cultures characterized by different cell densities and proliferation rates. Specifically, after ALA incubation under hypoxic or normoxic conditions, we detected spectrofluorometrically the PpIX content of the following populations: (a) low-density exponentially growing cells; (b) high-density fed-plateau cells; and (c) high-density unfed-plateau cells. These populations were selected either for the purpose of comparison with other in vitro studies (low-density exponentially growing cells) or as representatives of tumour regions adjacent to (high-density fed-plateau cells) and further away from (high-density unfed-plateau cells) capillaries. The amount of PpIX per cell produced by each one of these populations was higher after normoxic ALA incubation. The magnitude of the effect of hypoxia on PpIX synthesis was dependent on cell density and proliferation rate. A 42-fold decrease in PpIX fluorescence was observed for the high-density unfed-plateau cells. PpIX production by the low-density exponential cells was affected the least by ALA incubation under hypoxic conditions (1.4-fold decrease), whereas the effect on the high-density fed-plateau population was intermediate (20-fold decrease). © 1999 Cancer Research Campaig

In vivo tumor cell adhesion in the pulmonary microvasculature is exclusively mediated by tumor cell - endothelial cell interaction

<p>Abstract</p> <p>Background</p> <p>Metastasis formation is the leading cause of death among colon cancer patients. We established a new in-situ model of in vivo microscopy of the lung to analyse initiating events of metastatic tumor cell adhesion within this typical metastatic target of colon cancer.</p> <p>Methods</p> <p>Anaesthetized CD rats were mechanically ventilated and 10⁶human HT-29LMM and T84 colon cancer cells were injected intracardially as single cell suspensions. Quantitative in vivo microscopy of the lung was performed in 10 minute intervals for a total of 40 minutes beginning with the time of injection.</p> <p>Results</p> <p>After vehicle treatment of HT-29LMM controls 15.2 ± 5.3; 14.2 ± 7.5; 11.4 ± 5.5; and 15.4 ± 6.5 cells/20 microscopic fields were found adherent within the pulmonary microvasculature in each 10 minute interval. Similar numbers were found after injection of the lung metastasis derived T84 cell line and after treatment of HT-29LMM with unspecific mouse control-IgG. Subsequently, HT-29LMM cells were treated with function blocking antibodies against β1-, β4-, and αv-integrins wich also did not impair tumor cell adhesion in the lung. In contrast, after hydrolization of sialylated glycoproteins on the cells' surface by neuraminidase, we observed impairment of tumor cell adhesion by more than 50% (p < 0.05). The same degree of impairment was achieved by inhibition of P- and L-selectins via animal treatment with fucoidan (p < 0.05) and also by inhibition of the Thomson-Friedenreich (TF)-antigen (p < 0.05).</p> <p>Conclusions</p> <p>These results demonstrate that the initial colon cancer cell adhesion in the capillaries of the lung is predominantly mediated by tumor cell - endothelial cell interactions, possibly supported by platelets. In contrast to reports of earlier studies that metastatic tumor cell adhesion occurs through integrin mediated binding of extracellular matrix proteins in liver, in the lung, the continuously lined endothelium appears to be specifically targeted by circulating tumor cells.</p

The conceptual design of CLARA, a novel fel test facility for ultra-short pulse generation

CLARA will be a novel FEL test facility focussed on the generation of ultra-short photon pulses with extreme levels of stability and synchronisation. The principal aim is to experimentally demonstrate that sub-cooperation length pulse generation with FELs is viable, and to compare the various schemes being championed. The results will translate directly to existing and future X-ray FELs, enabling them to generate attosecond pulses, thereby extending their science capabilities. This paper gives an overview of the motivation for CLARA, describes the facility design (reported in detail in the recently published Conceptual Design Report [1]) and proposed operating modes and summarises the proposed areas of FEL research

Integrated Design at VIDA Centre Poland

Organised by: Cranfield UniversityThe modern design process forces the tight integration of processes connected with the development of the product. All the steps of the design process are based on geometrical models created in CAD systems. The geometry of the product is used for programming of the virtual environment of the product, its behaviour, manufacturing and so on. It is necessary to remember that the integrated design process needs special skills and knowledge from engineers. The authors of this paper presented a brief description of the VIDA Centre at Poznań University of Technology, its structure and skills in the area of integrated design. Couples of examples of projects realized at VIDA Centre’s environment as integrated design of products are described as well.Mori Seiki – The Machine Tool Compan

Structural intermediates in the assembly of taxoid-induced microtubules and GDP-tubulin double rings: time-resolved X-ray scattering

We have studied the self-association reactions of purified GDP-liganded tubulin into double rings and taxoid-induced microtubules, employing synchrotron time-resolved x-ray solution scattering. The experimental scattering profiles have been interpreted by reference to the known scattering profiles to 3 nm resolution and to the low-resolution structures of the tubulin dimer, tubulin double rings, and microtubules, and by comparison with oligomer models and model mixtures. The time courses of the scattering bands corresponding to the different structural features were monitored during the assembly reactions under varying biochemical conditions. GDP-tubulin essentially stays as a dimer at low Mg(2+) ion activity, in either the absence or presence of taxoid. Upon addition of the divalent cations, it associates into either double-ring aggregates or taxoid-induced microtubules by different pathways. Both processes have the formation of small linear (short protofilament-like) tubulin oligomers in common. Tubulin double-ring aggregate formation, which is shown by x-ray scattering to be favored in the GDP- versus the GTP-liganded protein, can actually block microtubule assembly. The tubulin self-association leading to double rings, as determined by sedimentation velocity, is endothermic. The formation of the double-ring aggregates from oligomers, which involves additional intermolecular contacts, is exothermic, as shown by x-ray and light scattering. Microtubule assembly can be initiated from GDP-tubulin dimers or oligomers. Under fast polymerization conditions, after a short lag time, open taxoid-induced microtubular sheets have been clearly detected (monitored by the central scattering and the maximum corresponding to the J(n) Bessel function), which slowly close into microtubules (monitored by the appearance of their characteristic J(0), J(3), and J (n) - (3) Bessel function maxima). This provides direct evidence for the bidimensional assembly of taxoid-induced microtubule polymers in solution and argues against helical growth. The rate of microtubule formation was increased by the same factors known to enhance taxoid-induced microtubule stability. The results suggest that taxoids induce the accretion of the existing Mg(2+)-induced GDP-tubulin oligomers, thus forming small bidimensional polymers that are necessary to nucleate the microtubular sheets, possibly by binding to or modifying the lateral interaction sites between tubulin dimers

Power and energy kneading of rye and wheat dough

Przeprowadzono badania sprawdzające w skałi przemysłowej opracowanej technołogii przygotowania nasion buraka ćwikłowego do siewu i przetestowano wykonane urządzenia. Nasiona przed siewem poddaje się obróbce połegająccj na skaryfikacji mechanicznej, ługowaniu wodą, suszeniu i kalibracji. Technologię obróbki nasion zastosowano dla wysiewu nasion ekologicznych.A technology for red beetroot seeds presowing treatment was elabora- ted and tested in a commercial scalę in specially designed for this technotogy machines and apparatus. The seeds underwent mechanica] po-lishing, water ieaching, drying and calibrating operations. Seeds used for the test were of organie type. It was found that the treatment resul-ted in the improvement in their germination parameters

Possibility of activation of mechanical interaction in the CIP washing process

Praca ma charakter analityczno-koncepcyjny. Na podstawie przeglądu literatury, badań własnych oraz obserwacji procesów przemysłowych przeanalizowano warunki mycia instalacji przemysłowych metodą CIP. Celem pracy była identyfikacja ograniczeń tej metody mycia, skutków energetycznych i środowiskowych oraz możliwości uaktywnienia mycia metodą CIP poprzez zastosowanie metod hybrydowych takich jak: oddziaływanie kawitacji ultradźwiękowej, barbotażu, piany oraz wkładek-korków przepływowych.This work presents an analytically-conceptual character. On the basis of literature survey, our own research and industrial process observation, CIP cleaning conditions of industrial lines were analyzed. The aim of this study was to identify limitations of this washing method, energy and environmental effects and the possibility of activating CIP washing using hybrid methods such as ultrasonic cavitation, bubbling, foam and inserts-flow caps

Impact analysis for individual factors in the process of system and equipment washing

W trakcie mycia instalacji i urządzeń powszechnie obecnie stosowaną metodą CIP (Cleaning In Place) występują specyficzne warunki usuwania zanieczyszczeń i utrzymania czystości powierzchni. Czynniki mechaniczne ograniczone są do oddziaływania cieczy w przepływie lub uderzania strugi cieczy. Dąży się do minimalizacji zużycia czynników chemicznych, ponieważ zbyt wysokie ich stężenie nie jest obojętne dla środowiska. W artykule przeanalizowano oddziaływanie czynników mechanicznych, ich skuteczność, zagrożenia i koniecznych badań. Celem jest analiza warunków i parametrów oddziaływania mechanicznego, aby uzyskać zadawalający efekt - czystość i sterylność mytych obiektów.Specific conditions for elimination of fouling and for maintaining surface cleanness occur during the installation and equipment washing using the CIP (Cleaning In Place) method, which is universally applied today. Mechanical factors are limited to the influence of liquid during flow, or liquid stream impact. The goal is to minimise the consumption of chemical agents, because their too high concentration is not indifferent to environment. The article contains analysis of the impact of mechanical factors, their efficiency, hazards, and necessary tests. The purpose is to analyse mechanical impact conditions and parameters in order to obtain satisfying effect - the cleanness and sterility of washed objects