Search

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jtcvs.2008.03.052 Byline: Frantisek Bednar (a), Pavel Osmancik (b), Tomas Vanek (a), Heidi Mocikova (c), Martin Jares (a), Zbynek Straka (a), Petr Widimsky (b) Abbreviations: ACT, activated clotting time; CABG, coronary artery bypass grafting; CPB, cardiopulmonary bypass; FITC, fluorescein isothiocyanate; MI, myocardial infarction; PRP, platelet-rich plasma Abstract: Changes in hemostasis after off-pump coronary artery bypass grafting are still being discussed. There is a lack of information about platelet activity and aspirin efficacy after coronary artery bypass grafting. The aim of this study was to assess and compare platelet activity and aspirin efficacy early and late after off-pump and on-pump coronary artery bypass grafting. Author Affiliation: (a) Cardiocenter, Department of Cardiac Surgery, 3rd Medical School, Charles University and University Hospital Kralovske Vinohrady, Prague, Czech Republic (b) Cardiocenter, Department of Cardiology, 3rd Medical School, Charles University and University Hospital Kralovske Vinohrady, Prague, Czech Republic (c) Department of Clinical Hematology, 3rd Medical School, Charles University and University Hospital Kralovske Vinohrady, Prague, Czech Republic Article History: Received 20 October 2007; Revised 13 February 2008; Accepted 7 March 2008 Article Note: (footnote) Supported by research grant no. 8526-3/2005 from the Internal Grant Agency of the Ministry of Health of the Czech Republic.

Environmental contextBioaccumulation of nanoparticles in plants used for food and feed could be a major exposure pathway to nanoparticles, resulting in ecological and health risks. Isotopic labelling of nanoparticles enables their sensitive tracing in the presence of background elements in complex plant matrices. We investigate nine individual cases of plant–NP interactions and show the role of plants in the uptake and translocation of nanoparticles or their dissolution into metals. AbstractUnintended releases of nanoparticles (NPs) into agricultural soil have recently raised concerns regarding NP accumulation in plants. In this study, specially synthesised isotopically labelled 107Ag-NPs, 65Cu-NPs and 70ZnO-NPs were exposed to three representative plants (Arabidopsis thaliana, Solanum lycopersicum (tomato) and Phragmites australis (common reed)) in hydroponic cultivation and, separately, to tomato plants cultivated in soil at concentrations of 2mgL−1. Metal concentrations in all samples were analysed by inductively coupled plasma mass spectrometry following acid digestion. The use of isotopically labelled NPs confirmed that elevated levels of metals were from the NP source used for the experiments. Although the highest concentrations of NPs or metals were detected in roots in both hydroponic and soil cultivations, varied levels of translocation to shoots were observed in different plants under hydroponic cultivation. In soil cultivation, where tomato plants were grown to full maturity, low levels of 107Ag (0.38mgkg−1) with respect to controls were recorded in tomato fruits; 70Zn showed the highest level of translocation to tomato stems (2.72mgkg−1) and leaves (13.93mgkg−1). Furthermore, the amounts of NPs retained in the soil (at different depths) after harvesting tomato plants were also determined; the highest concentrations of respective isotopes (1.25mgkg−1 of 107Ag, 0.79mgkg−1 of 65Cu, 4.06mgkg−1 of 70Zn) were found in the top soil layer (~3cm). Analysis of NPs exposed to plants in hydroponic medium indicated that the presence of plants increases the dissolution of NPs. Scanning electron microscopy analysis enabled determination of the location of 107Ag-NPs in the roots of tomato plants grown in soil; these NPs were found to accumulate mainly in the cortical cells.

Strigolactones are a particular class of plant metabolites with diverse biological functions starting from the stimulation of parasitic seed germination to phytohormonal activity. The expansion of parasitic weeds in the fields of developing countries is threatening the food supply and calls for simple procedures to combat these weeds. Strigolactone analogues represent a promising approach for such control through suicidal germination, i.e., parasitic seed germination without the presence of the host causing parasite death. In the present work, the synthesis of resorcinol-type strigolactone mimics related to debranones is reported. These compounds were highly stable even at alkaline pH levels and able to induce seed germination of parasitic plants Striga hermonthicaand Phelipanche ramosaat low concentrations, EC50≈ 2 × 10–7M (Striga) and EC50≈ 2 × 10–9M (Phelipanche). On the other hand, the mimics had no significant effect on root architecture of Arabidopsisplants, suggesting a selective activity for parasitic seed germination, making them a primary target as suicidal germinators.

Strigolactones are the most recently recognized class of phytohormones, which are also known to establish plant symbiosis with arbuscular mycorhizal fungi or induce germination of parasitic plants. Their relatively complex structures and low stability urgently calls for simple derivatives with maintained biological function. We have prepared a series of triazolide strigolactone mimics and studied their ability to affect root development of Arabidopsis thaliana. The strigolactone mimics significantly induced root elongation and lateral root formation while resembling the effect of the reference compound GR24.

This review covers the chemical reactions, synthesis, and biological activities of tetracyclic diterpenoids including ent-kauranes, ent-beyeranes, ent-atisanes, ingenanes, tyglianes, stemodanes, stemaranes, sordarin, salvileucalin B, harringtonolide and hainanolidol. It comprises of the un-reviewed references from the year 2000.

In this study, ten anthra, nine naphtho, and five benzoquinone compounds of natural origin and five synthetic naphthoquinones were assessed, using an enzymatic in vitro assay, for their potential to inhibit cyclooxygenase-1 and -2 (COX-1 and COX-2), the key enzymes of the arachidonic acid cascade. IC50 values comparable with COX reference inhibitor indomethacin were recorded for several quinones (primin, alkannin, diospyrin, juglone, 7-methyljuglone, and shikonin). For some of the compounds,we suggest the redox potential of quinones as the mechanism responsible for in vitro COX inhibition because of the quantitative correlation with their pro-oxidant effect. Structure-relationship activity studies revealed that the substitutions at positions 2 and 5 play the key roles in the COX inhibitory and pro-oxidant actions of naphthoquinones. In contrast, the redox mechanism alone could not explain the activity of primin, embelin, alkannin, and diospyrin. For these four quinones, molecular modeling suggested similar binding modes as for conventional nonsteroidal anti-inflammatory drugs (NSAIDs). [ABSTRACT FROM AUTHOR]

Sixty-five patients scheduled for coronary surgery were randomized into three groups: A - conventional coronary artery bypass grafting, B - off-pump surgery, C - coronary artery bypass grafting with modified, rheoparin coated cardiopulmonary bypass with the avoidance of re-infusion of cardiotomy blood into the circuit. On the completion of peripheral bypass anastomoses, highly significant inter-group differences were found in the thromboelastographic parameter lysis of set time at 60 min of assessment (P=0.003) and at 150 min of assessment (P<0.001), the mean values of these parameters were significantly lower in group A as compared with both groups B and C, which were statistically indistinguishable. Lysis on set time on the completion of peripheral bypass anastomoses <50% was detected in 12 patients (52.2%) originating from group A. At the other sampling times (preoperatively, 15 min after sternotomy, at the end of the procedures, and 24 h later) thromboelastographic parameters were similar in all groups. In group A no significant correlations between lysis on set time, postoperative blood loss and D-dimer levels were found. Based on our results, thromboelastographic signs of fibrinolysis were clearly detectable during cardiopulmonary bypass in group A, but not at any time in groups B and C.

Crude methanol extracts from callus cultures of Nigella arvensis, N. damascena, N. hispanica, N. integrifolia, and N. sativa were investigated for their anti-microbial activity. Growth inhibition was determined in Gram-positive and Gram-negative bacterial strains as well as in yeast by using a broth-microdilution method. The results showed that the extracts of all calli tested exhibited significant anti-microbial activity, especially against Bacillus cereus, Staphylococcus aureus and Staphylococcus epidermidis. Compared with other Nigella species, a callus culture of N. hispanica was the most effective against the microorganisms used in this study.

Arabidopsis thaliana was transformed with a gene encoding a nitroreductase (NTR, E.C. 1.6.99.7) with activity against a wide range of nitroaromatic compounds. The gene was transferred from Escherichia coli by an Agrobacterium-mediated in planta method. The ob­tained seeds were sowed to produce T1 plants, and they were assayed for the integration of the transgene in the plant genome. Transgenic plants that were positive with the PCR analysis were self-pollinated to produce T2 generation plants. Seven lines obtained were assayed for the NTR activity. While the noil-transformed wild-type plants showed no detectable NTR activity, the enzyme activity of the transgenic plant lines was approx. 20 times higher. Using the line with the highest NTR activity, the phytoremediation characteristics of plants against 2,4,6-trinitrotoluene (TNT) was investigated. While the wild-type plants did not grow in the presence of 0.1 m? TNT, the transgenic plants grew almost normally in this condition. The uptake of TNT by seedlings of transgenic plants increased by 7 to 8 times when they were floated on TNT solution. HPLC analysis showed that the peak due to TNT taken up into plant body was much smaller in the transgenic plants as compared with that of the wild type, and that a number of peaks attributable to the degradation products of TNT, including 4-amino-2,6-dinitrotoluene, were detected in the extract from the transgenic plants. This indi­cates that the expression of bacterial NTR improved the capability of plants to degrade TNT.

Background: Increasing awareness in the last decade concerning environmental quality had prompted research into ‘green solutions’ for soil and water remediation, progressing from laboratoryin vitroexperiments to pot and field trials. Objective: This paper is a joint effort of a group of scientists in COST action 837. It represents experimental work and an overview on plant response to environmental stress fromin vitrotissue culture to whole plant experiments in soil. Results: Results obtained fromin vitroplant tissue cultures and whole plant hydroponic experiments indicate the phytoremediation potential of different plant species and the biochemical mechanisms involved in plant tolerance. In pot experiments, several selected desert plant species, which accumulated heavy metal in hydroponic systems, succeeded in accumulating the heavy metal in soil conditions as well. Conclusions and Recommendations: In vitroplant tissue cultures provide a useful experimental system for the study of the mechanisms involved in the detoxification of organic and heavy metal pollutants. However, whole plant experimental systems, as well as hydroponics followed by pot and field trials, are essential when determining plant potential to remediate polluted sites. Multidisciplinary research teams can therefore increase our knowledge and promote a practical application of phytoremediation.

Sulfonated aromatic compounds are released into the environment in large amounts: the main sources of these recalcitrant pollutants are anionic detergents, dyestuffs, and their byproducts, such as sulfonated anthraquinones. Different derivatives of anthraquinones occur naturally in several plant species such as rhubarb. Therefore, this plant could possess enzymes able to accept sulfonated anthraquinones as substrates. Previously, it has been shown that cultured cells isolated from Rheum palmatum are able to efficiently accumulate and transform different mono- and disulfonated anthraquinones. Because rhubarb is a hardy plant species, it may prove a promising candidate in developing new biological processes to decontaminate effluents containing recalcitrant xenobiotics. The ability of rhubarb cells to accumulate and transform other sulfonoaromatics was investigated in this study. Results obtained show that cultured rhubarb cells were able to efficiently accumulate 2-chloro-5-nitro-benzene sulfonate, both 2-hydroxy-4-sulfo- and 2-hydroxy-4-sulfo-6-nitro-naphthalene-diazonium, as well as 1,3-naphthalene disulfonates, containing either an amino or a nitro group in position 7. Rhubarb cells were also able to biotransform four of these compounds without releasing the metabolites formed.

The author reports tests at CVUT, the Czech Technical University, which verified the feasibility of strengthening existing concrete beams suffering bending stress. Steel strip and plate may be used as reinforcement, glued to the bottom or side surface of the beam by epoxy-based resins, sometimes with drilled dowels to provide a kind of extra strut frame. The promise of this technique for modernising old factories has led to further studies into its use for increasing flexural and shear strength.

Qu'elles soient appliquees dans le cadre d'une operation generale de remise en etat ou pour remedier a un defaut de la construction d'origine, les techniques de renforcement in situ des constructions en beton arme ont ete considerablement developpees en Tchecoslovaquie. Un maitre de conference de la faculte de la construction a l'Universite Technique tcheque de Prague resume les resultats des essais effectues sur les vieilles dalles de planchers qui ont ete renforcees par l'addition d'une nouvelle couche de beton.

In our March-April issue last year, the author described work at the Czech Technical University in Prague on the use of epoxy resins to apply new flat reinforcement to old concrete beams in order to enhance or prolong their service life. Here, some further test results and general conclusions are presented on the application of this technique to shear strengthening. The author is Associate Professor of Civil Engineering at the University.

We present a case of a 62-year-old male patient (coronary heart disease, and stenosis of aortic valve) with severe left ventricular dysfunction (left ventricular ejection fraction 20%, left ventricular end-diastolic diameter 80 mm, end-diastolic volume 329 ml) who developed giant electrical storm (on the whole 115 episodes of pulseless ventricular tachycardia treated by antiarrhythmics and electrical discharges) with low-elevation of cardiac biomarkers. The patient was referred to emergent cardiac surgery (double coronary bypass grafting, aortic valve replacement, and implantation of left ventricular epicardial electrode). Levosimendan and intraaortic balloon counterpulsation were used for successful weaning from the cardiopulmonary bypass; no other arrhythmia appeared in the post-bypass period. Postoperatively no arrhythmic events were detected, and repeated echocardiographic examinations of the patient in good general condition showed gradual improvement of left ventricular ejection fraction (30-35%), likewise in other parameters (left ventricular end-diastolic diameter 72 mm, end-diastolic volume 285 ml).

Quinones are compounds frequently contained in medicinal plants used for the treatment of inflammatory diseases. Therefore, the impact of plant-derived quinones on the arachidonic acid metabolic pathway is worthy of investigation. In this study, twenty-three quinone compounds of plant origin were tested in vitrofor their potential to inhibit leukotriene B4 (LTB4) biosynthesis in activated human neutrophil granulocytes with 5-lipoxygenase (5-LOX) activity. The benzoquinones primin (3) and thymohydroquinone (4) (IC50 = 4.0 and 4.1 μM, respectively) showed activity comparable with the reference inhibitor zileuton (IC50 = 4.1 μM). Moderate activity was observed for the benzoquinone thymoquinone (2) (IC50 = 18.2 μM) and the naphthoquinone shikonin (1) (IC50 = 24.3 μM). The anthraquinone emodin and the naphthoquinone plumbagin (5) displayed only weak activities (IC50 > 50 μM). The binding modes of the active compounds were further evaluated in silicoby molecular docking to the human 5-LOX crystal structure. This process supports the biological data and suggested that, although the redox potential is responsible for the quinone's activity on multiple targets, in the case of 5-LOX the molecular structure plays a vital role in the inhibition. The obtained results suggest primin as a promising compound for the development of dual COX-2/5-LOX inhibitors.

Whether done as part of general restoration work or to remedy a defect in the original construction, techniques for in situ strengthening of existing reinforced concrete structures have been considerably developed in Czechoslovakia. Here a senior lecturer in the building faculty of the Czech Technical University in Prague summarises the results of tests on old floor slabs which have been strengthened by the addition of a new concrete layer.