Bioresorbable scaffolds: a new paradigm in percutaneous coronary intervention

Numerous advances and innovative therapies have been introduced in interventional cardiology over the recent years, since the first introduction of balloon angioplasty, but bioresorbable scaffold is certainly one of the most exciting and attracting one. Despite the fact that the metallic drug-eluting stents have significantly diminished the re-stenosis ratio, they have considerable limitations including the hypersensitivity reaction to the polymer that can cause local inflammation, the risk of neo-atherosclerotic lesion formation which can lead to late stent failure as well as the fact that they may preclude surgical revascularization and distort vessel physiology. Bioresorbable scaffolds overcome these limitations as they have the ability to dissolve after providing temporary scaffolding which safeguards vessel patency. In this article we review the recent developments in the field and provide an overview of the devices and the evidence that support their efficacy in the treatment of CAD. Currently 3 devices are CE marked and in clinical use. Additional 24 companies are developing these kind of coronary devices. Most frequently used material is PLLA followed by magnesium

Purification, characterization and application of laccase from Trametes versicolor for colour and phenolic removal of olive mill wastewater in the presence of 1- hydroxybenzotriazole

Laccase forms (L1 and L2) from Trametes versicolor CCT 4521 showed a molecular mass of 66 kDa and optimum temperature around 40oC. The optimum pH (4.0 and 5.0) and Km (28.6 and 5 ìM) values usingsyringaldazine as substrate were found for L1 and L2, respectively. The enzymes were able to oxidize several compounds and were strongly inhibited by sodium azide, L-cysteine and dithiothreitol. The 75%of the N-terminal sequences were identical in both forms and similarities around 40 - 60% of laccases from wood-degrading fungi were observed. The use of 1-hydroxybenzotriazole as a mediator increased the compounds oxidized by laccases in olive mill wastewater

Justification for the use of Ocimum gratissimum L in herbal medicine and its interaction with disc antibiotics

<p>Abstract</p> <p>Background</p> <p>The ethanolic extract of the leaves of <it>Ocimium gratisimum </it>L. (Lamiaceae), used in traditional medicine for the treatment of several ailments such as urinary tract, wound, skin and gastrointestinal infections, was evaluated for its antibacterial properties against four clinical bacteria isolates namely: <it>Escherichia coli, Proteus mirabilis, Staphylococcus aureus and Pseudomonas aeruginosa </it>and the antifungal properties using a clinical isolate of <it>Candida albicans</it>. A typed bacterium of <it>Escherichia coli </it>ATCC 11775 and another typed fungal strain of <it>Candida albicans </it>(ATCC 90028) were also included. The study also intended to verify if the concomitant administration of conventional antibiotics with <it>Ocimium gratisimum </it>which is normally taken as food (spice) will negatively affect its activity.</p> <p>Methods</p> <p>The agar diffusion method was used to test the in vitro activity of the plant extract. The interaction of the plant extract with some disc antibiotics namely: ciprofloxacin, septrin, streptomycin, ampicillin, nystatin and ketoconazole was tested using the agar overlay inoculum susceptibility disc method. Phytochemical analysis of the extract was performed following established methods.</p> <p>Results</p> <p>The extract showed good but varying <it>in vitro </it>activities against all the isolates tested. While ampicillin showed synergistic interaction with the plant extract against clinical isolates of <it>E. coli </it>and <it>P. mirabilis</it>, septrin was synergistic against the clinical isolate of <it>E. coli </it>only. Similarly, the activity of the extract against <it>C. albicans </it>isolate was synergistic with ketoconazole and nystatin.</p> <p>Conclusion</p> <p>The study has validated the folkloric use of <it>O. gratissimum </it>in traditional medicinal practice and goes further to show that the use of this plant material as food spice may not really threaten the efficacy of some conventional antibiotics that may have been taken concomitantly with it as is the popular belief in the practice of herbal medicine in local/rural communities of many countries in the world.</p

Prevalence of scarred and dysfunctional myocardium in patients with heart failure of ischaemic origin: a cardiovascular magnetic resonance study

BACKGROUND: Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) can provide unique data on the transmural extent of scar/viability. We assessed the prevalence of dysfunctional myocardium, including partial thickness scar, which could contribute to left ventricular contractile dysfunction in patients with heart failure and ischaemic heart disease who denied angina symptoms. METHODS: We invited patients with ischaemic heart disease and a left ventricular ejection fraction < 50% by echocardiography to have LGE CMR. Myocardial contractility and transmural extent of scar were assessed using a 17-segment model. RESULTS: The median age of the 193 patients enrolled was 70 (interquartile range: 63-76) years and 167 (87%) were men. Of 3281 myocardial segments assessed, 1759 (54%) were dysfunctional, of which 581 (33%) showed no scar, 623 (35%) had scar affecting ≤50% of wall thickness and 555 (32%) had scar affecting > 50% of wall thickness. Of 1522 segments with normal contractile function, only 98 (6%) had evidence of scar on CMR. Overall, 182 (94%) patients had ≥1 and 107 (55%) patients had ≥5 segments with contractile dysfunction that had no scar or ≤50% transmural scar suggesting viability. CONCLUSIONS: In this cohort of patients with left ventricular systolic dysfunction and ischaemic heart disease, about half of all segments had contractile dysfunction but only one third of these had > 50% of the wall thickness affected by scar, suggesting that most dysfunctional segments could improve in response to an appropriate intervention

Using of essential oils in the treatment of mice infected with Trypanosoma evansi

Objective. This study aimed to test the effectiveness of copaiba, andiroba and aroeira essential oils for controlling trypanosomosis by Trypanosoma evansi with mice as experimental model. Materials and methods. Sixty-six mice were divided into eleven groups (A to L) with six animals each. Group A was the unique composed by healthy and uninfected animals (negative control). Animals in groups B to L were inoculated with 0.1 mL of blood containing 2.7 x 106 trypanosomes. Group B was used as a positive control without treatment. In experiment were tested copaiba (C, D and E), andiroba (F, G and H) and aroeira (I, J and L) oils at doses of 0.6, 0.8 and 1.0 mL kg-1 to infected mice (T. evansi). Results. These protocols did not provide curative efficacy; however, the mice treated with highest dose of copaiba showed a significant increase in the longevity when compared others groups. Conclusions. Previously in our studies, these essential oils have shown trypanocidal activity in vitro, but when they were tested in vivo in mice infected with T. evansi, this trypanocidal activity, or the curative effect was not found, being only able to prolong the lifespan of the animals treated with copaiba oil

Characterization of two heparan sulphate-binding sites in the mycobacterial adhesin Hlp

<p>Abstract</p> <p>Background</p> <p>The histone-like Hlp protein is emerging as a key component in mycobacterial pathogenesis, being involved in the initial events of host colonization by interacting with laminin and glycosaminoglycans (GAGs). In the present study, nuclear magnetic resonance (NMR) was used to map the binding site(s) of Hlp to heparan sulfate and identify the nature of the amino acid residues directly involved in this interaction.</p> <p>Results</p> <p>The capacity of a panel of 30 mer synthetic peptides covering the full length of Hlp to bind to heparin/heparan sulfate was analyzed by solid phase assays, NMR, and affinity chromatography. An additional active region between the residues Gly46 and Ala60 was defined at the N-terminal domain of Hlp, expanding the previously defined heparin-binding site between Thr31 and Phe50. Additionally, the C-terminus, rich in Lys residues, was confirmed as another heparan sulfate binding region. The amino acids in Hlp identified as mediators in the interaction with heparan sulfate were Arg, Val, Ile, Lys, Phe, and Thr.</p> <p>Conclusion</p> <p>Our data indicate that Hlp interacts with heparan sulfate through two distinct regions of the protein. Both heparan sulfate-binding regions here defined are preserved in all mycobacterial Hlp homologues that have been sequenced, suggesting important but possibly divergent roles for this surface-exposed protein in both pathogenic and saprophic species.</p

Bridging Time Scales in Cellular Decision Making with a Stochastic Bistable Switch

Cellular transformations which involve a significant phenotypical change of the cell's state use bistable biochemical switches as underlying decision systems. In this work, we aim at linking cellular decisions taking place on a time scale of years to decades with the biochemical dynamics in signal transduction and gene regulation, occuring on a time scale of minutes to hours. We show that a stochastic bistable switch forms a viable biochemical mechanism to implement decision processes on long time scales. As a case study, the mechanism is applied to model the initiation of follicle growth in mammalian ovaries, where the physiological time scale of follicle pool depletion is on the order of the organism's lifespan. We construct a simple mathematical model for this process based on experimental evidence for the involved genetic mechanisms. Despite the underlying stochasticity, the proposed mechanism turns out to yield reliable behavior in large populations of cells subject to the considered decision process. Our model explains how the physiological time constant may emerge from the intrinsic stochasticity of the underlying gene regulatory network. Apart from ovarian follicles, the proposed mechanism may also be of relevance for other physiological systems where cells take binary decisions over a long time scale.Comment: 14 pages, 4 figure