Search

Background: Angiogenesis and haemostasis are closely linked within tumours with many haemostatic proteins regulating tumour angiogenesis. Indeed we previously identified a fragment of human fibrinogen, fibrinogen E-fragment (FgnE) with potent anti-angiogenic properties in vitro and cytotoxic effects on tumour vessels in vivo. We therefore investigated which region of FgnE was mediating vessel cytotoxicity.Methods: Human dermal microvascular endothelial cells (ECs) were used to test the efficacy of peptides derived from FgnE on proliferation, migration, differentiation, apoptosis and adhesion before testing the efficacy of an active peptide on tumour vasculature in vivo.Results: We identified a 20-amino-acid peptide derived from the beta chain of FgnE, beta43-63, which had no effect on EC proliferation or migration but markedly inhibited the ability of activated ECs to form tubules or to adhere to various constituents of the extracellular matrix - collagen IV, fibronectin and vitronectin. Furthermore, our data show that beta43-63 interacts with ECs, in part, by binding to alpha(v)beta(3), so soluble alpha(v)beta(3) abrogated beta43-63 inhibition of tubule formation by activated ECs. Finally, when injected into mice bearing tumour xenografts, beta43-63 inhibited tumour vascularisation and induced formation of significant tumour necrosis.Conclusions: Taken together, these data suggest that beta43-63 is a novel anti-tumour peptide whose anti-angiogenic effects are mediated by alpha(v)beta(3). [ABSTRACT FROM AUTHOR]

1. A subcellular amino acid incorporating system has been obtained from the psychrophilic bacterium Pseudomonas sp. 412. The system is active from near 0° to 45°, i. e. about 15° above the maximal growth temperature of the organism. The Mg2+ requirement of the system increases from 7mM at 2° to 14-18mM at 45°. 2. The sedimentation properties and optical density melting profiles of ribosomes from Pseudomonas sp. 412 have been found similar to those of Escherichia coli ribosomes. 3. The poly U-induced leucine incorporation is negligible in this system as compared to the E. coli and Bacillus stearothermophilus systems. 4. The ribosomes and supernatant fractions of Pseudomonas sp. 412 and E. coli are interchangeable at 30-45° in the poly U-promoted phenylalanine incorporation. At 2-9° only Pseudomonas sp. 412 ribosomes are active with both supernatant fractions. The ability to perform protein synthesis near 0° is related to ribosomal specificity. The E. coli soluble enzymes are active near 0° if combined with the ribosomes from the psychrophilic strain. [ABSTRACT FROM AUTHOR]

Erythrocyte membrane fluidity, membrane potential and acetylcholinesterase activity were estimated after in vitro combined treatment of human erythrocytes with perindoprilat and low-power red light irradiation. Membrane fluidity was determined using fluorescent labels spectroscopy; membrane potential was evaluated by means of potential-sensitive fluorescent dyes; and acetylcholinesterase activity was estimated using the Ellman method. Both perindoprilat and laser irradiation, when used separately, increase microviscosity in the polar region and hyperpolarize the membranes in comparison with control erythrocytes. The combined action of these agents does not cause any further change in these parameters. Perindoprilat has an additional inhibitory effect on the activity of acetylcholinesterase, whereas laser irradiation causes an increase in the activity of the enzyme. Their combined action restores the initial activity of the enzyme independently of the sequence of treatment with both agents. [ABSTRACT FROM AUTHOR]

The effects of perindoprilat on the morphology and dynamic properties of human erythrocytes were studied by light microscopy, electron spin resonance spectroscopy and spectrophotometric methods. Erythrocytes were exposed to perindoprilat at 37°C for 30 and 120 min. It was shown that the drug at a concentration of 0.75 μg/ml did not cause significant changes in the structure of erythrocyte membranes. Higher doses of the drug (7.5 and 75 mg/ml) induced changes in membrane fluidity in the hydrophobic core of the lipid bilayer, the conformation of membrane proteins, the number of SH groups and the activity of membrane-bound acetylcholinesterase (AChE). These modifications were accompanied by changes in the shape of erythrocytes and did not depend on time of incubation. Therefore, it is proposed that perindoprilat perturbs the lipid bilayer and disturbs the organization of the protein-lipid environment. [ABSTRACT FROM AUTHOR]

Urazy i uszkodzenia implantów piersi są jednymi z możliwych powikłań operacji estetycznych i rekonstrukcyjnych w obrębie piersi. Uszkodzenia protez mogą być zarówno objawowe, jak i niewykrywalne w podstawowym badaniu fizykalnym. Celem pracy był przegląd literatury naukowej w celu określenia sposobu postępowania w poszczególnych rodzajach uszkodzenia protez piersi wraz z opisem przypadków klinicznych. Wnioski Operacje w obrębie gruczołów piersiowych są jednymi z najczęściej przeprowadzanych przez chirurgów plastycznych. Najprawdopodobniej implanty piersi najczęściej ulegają uszkodzeniu jatrogennie, a odsetek uszkodzeń potwierdzonych w badaniu rezonansu magnetycznego sięga 16% po 8 latach obserwacji od wszczepienia protezy piersi. W przypadku uszkodzenia protezy postępowanie zależy od stopnia uszkodzenia (tzw. krwawienia implantu, wycieku w obrębie torebki lub wycieku poza torebkę) oraz od aktualnej sytuacji klinicznej. Pomimo braku dedykowanego systemu nadzoru nad pacjentami po tego typu zabiegach, konieczna jest systematyczna kontrola pod kątem uszkodzenia implantów piersi. [ABSTRACT FROM AUTHOR]