Green synthesis of anisotropic gold nanoparticles using hordenine and their antibiofilm efficacy against Pseudomonas aeruginosa

Pseudomonas aeruginosa is a notorious pathogen that causes biofilm aided infections in patients with cystic fibrosis and burn wounds, resulting in significant mortality in immunocompromised individuals. This study reports a novel one‐step biosynthesis of gold nanoparticles using phytocompound, hordenine (HD), as a reducing and capping agent. The synthesis of the anisotropic hordenine‐fabricated gold nanoparticles (HD‐AuNPs) with an average particle size of 136.87 nm was achieved within 12 h of incubation at room temperature. Both HD and HD‐AuNPs exhibited significant antibiofilm activity against P. aeruginosa PAO1, although greater biofilm inhibition was observed for the nanoparticles as compared to hordenine alone. In the microtitre plate assay and tube method, the nanoparticles significantly inhibited the biofilm formation by 73.69 and 78.41%, respectively. The exopolysaccharide production by the test pathogen was arrested by 68.46% on treatment with the nanoparticles. Further, the effect of HD and HD‐AuNPs on the biofilm architecture of P. aeruginosa was revealed by light and confocal laser‐scanning microscopy micrographs. The overall results of this study suggested the synergistic antibiofilm effect of AuNPs and HD for the treatment of chronic bacterial infections caused by biofilms forming pathogens.Inspec keywords: molecular biophysics, biochemistry, gold, nanoparticles, nanofabrication, microorganisms, organic compounds, particle size, nanobiotechnologyOther keywords: green synthesis, anisotropic gold nanoparticles, hordenine, antibiofilm efficacy, Pseudomonas aeruginosa, pathogen, cystic fibrosis, burn wounds, one‐step biosynthesis, phytocompound, reducing agent, capping agent, particle size, microtitre plate assay, tube method, confocal laser‐scanning microscopy micrographs, Au     

Larvicidal activity of green synthesized silver nanoparticles using Excoecaria agallocha L. (Euphorbiaceae) leaf extract against Aedes aegypti

Green synthesis of silver nanoparticles (AgNPs) using plant extracts has been achieved by eco‐friendly reducing and capping agents. The present study was conducted to evaluate the larvicidal efficacies of AgNPs synthesized using aqueous leaf extracts of Excoecaria agallocha against dengue vector, Aedes aegypti. The 3^rd and 4^th instar larvae of A. aegypti were exposed to various concentrations of aqueous extracts of E. agallocha, synthesized AgNPs and also crude solvent extracts (methanol and chloroform) for 24 h. The formation of AgNPs using aqueous leaf extracts was observed after 30 min with a characteristic colour change. The results recorded from UV‐Vis spectrum, XRD, FTIR, EDX, SEM and HR‐TEM were used to characterize and confirm the biosynthesis of AgNPs. The highest larvicidal efficacy of synthesized AgNPs was observed against 3^rd instar larvae at LC₅₀ 4.65 mg/L, LC₉₀ 14.17 mg/L and 4^th instar larvae with a concentration of LC₅₀ 6.10 mg/L, LC₉₀ 15.64 mg/L. A significant larvicidal activity was also observed with crude methanolic extracts against 3^rd instar larvae at a concentration LC₅₀ 41.74 mg/L, LC₉₀ 123.61 mg/L and 4^th instar larvae at a concentration of LC₅₀ 52.06 mg/L, LC₉₀ 166.40 mg/L as compared to the chloroform extract.Inspec keywords: silver, nanoparticles, nanofabrication, microorganisms, cellular biophysics, organic compounds, ultraviolet spectra, visible spectra, X‐ray diffraction, Fourier transform infrared spectra, X‐ray chemical analysis, scanning electron microscopy, transmission electron microscopyOther keywords: larvicidal activity, green synthesised silver nanoparticles, Excoecaria agallocha L. leaf extract, Aedes aegypti, plant extracts, capping agents, larvicidal efficacies, aqueous leaf extracts, excoecaria agallocha, dengue vector, Aedes aegypti, aegypti, aqueous extraction, E. agallocha, crude solvent extracts, methanol, chloroform, characteristic colour change, ultraviolet‐visible spectrum, X‐ray diffraction, Fourier‐transform infrared spectroscopy, EDX, scanning electron microscopy, high‐resolution transmission electron microscopy, AgNP biosynthesis, larvicidal efficacy, third instar larvae, instar larvae, crude methanolic extracts, chloroform extraction, time 24 h     

Stenting after optimal lesion debulking (sold) registry. Angiographic and clinical outcome

BACKGROUND: Coronary stenting has reduced restenosis in focal de novo lesions, but its impact has been less pronounced in complex lesion subsets. Preliminary data suggest a role for plaque burden in promoting intimal hyperplasia after stent implantation. The aim of this study was to test the hypothesis that plaque removal with directional atherectomy before stent implantation may lower the intensity of late neointimal hyperplasia, reducing the incidence of in-stent restenosis. METHODS AND RESULTS: Seventy-one patients with 90 lesions underwent directional atherectomy before coronary stenting. Intravascular ultrasound-guided stenting was performed in 73 lesions (81%). Clinical success was achieved in 96% of patients. Procedural complications were as follows: emergency bypass surgery in 1 patient (1.4%), who died 2 weeks later; Q-wave myocardial infarction in 2 patients (2.8%); and non-Q-wave myocardial infarction in 8 patients (11.3%). None of the patients had stent thrombosis at follow-up. Angiographic follow-up was performed in 89% of eligible patients at 5.7+/-1.7 months. Loss index was 0.33 (95% CI, 0.26 to 0.40), and angiographic restenosis was 11% (95% CI, 5% to 20%). Clinical follow-up was performed in all patients at 18+/-3 months. Target lesion revascularization was 7% (95% CI, 3% to 14%). CONCLUSIONS: Directional atherectomy followed by coronary stenting could be performed with good clinical success rate. Also, these data point to a possible reduction in angiographic restenosis and a significant reduction in the need for repeated coronary interventions. Therefore, a randomized clinical trial seems appropriate to test the validity of this approach.     

In situ ATR/FTIR studies of protein adsorption on polymeric materials: effectiveness of surface heparinization

The adsorption of two proteins from human plasma (human serum albumin (HSA) and human fibrinogen (HFG) onto six different polymeric surfaces (two of which are heparinized), has been studied byin situ ATR/FTIR spectroscopy. The different surface characteristics are reflected by different interfacial behaviours of the two proteins, but while both proteins unfold upon adsorption on all the different non-heparinized materials, they maintain the native conformation once adsorbed on the heparinized surfaces. These findings emphasize the effectiveness of surface heparinization.     

Efficient Stochastic Simulation of Biological Systems with Multiple Variable Volumes

The application of concurrent calculi to the formalisation of biological systems constitutes a promising approach to the analysis in silico of biological phenomena. The Gillespie algorithm is one of the main models exploited for their stochastic simulation. While the original algorithm considers only one fixed-volume compartment, the simulation of biological systems often requires multi-compartment semantics. In this paper we present an enhanced formulation of an extended version of the algorithm which handles multiple compartments with varying volumes. The presented algorithm is used as basis for the implementation of an extension of the stochastic π-Calculus, called Sπ@, which allows an intuitive and concise formalisation of such systems. The algorithm is also efficient in presence of a high number of compartments and reactions, therefore Sπ@ represents the starting point for the development of an effective tool for the simulation of biological systems with dynamical structure even in presence of computationally expensive phenomena like diffusion.     

The determination of amanitines in the serum of patients poisoned by amanita phalloides (author's transl)

The serum of patients suffering from Amanita phalloides poisoning was analysed in order to determine whether amanitines, which are the principal toxins of this fungus, were still present in the blood at the time of hospitalisation. In addition, the authors measured the concentrations of amanitines in the blood of dogs at different intervals after the ingestion of a fatal dose of Amanita phalloides. Amanitines were detected in the serum of 9 patients out of 16. This discovery, together with the finding that, in the dog, very low concentrations of amanitines in the blood are associated with fatal cellular lesions, suggests the need for very prompt action in order to eliminate these toxins from the blood as soon as the diagnosis of poisoning is suspected.     

Spine and spinal cord war injuries during the war in Croatia

OBJECTIVE: The present report summarizes the experience of an evacuation hospital in southern Croatia in treating 96 patients with spine and spinal cord war injuries. METHODS: A retrospective review was done for 96 wounded persons (86 soldiers, 10 civilians) with spinal cord injuries from August 1991 through December 1995. The ages ranged from 15 to 59 years (mean, 28.3 years for soldiers, 38.5 years for civilians). Diagnostic procedures were plain radiography, computed tomography, and computed tomographic myelography. However, in most cases a more conservative surgical approach was used. RESULTS: The highest rates of admittance were recorded in 1992 (N = 38) and 1993 (N = 47). The lumbar spine was injured in 55% of the patients, the cervical and thoracic spines in 17.7%. All injuries were caused by projectiles from automatic rifles and sniper fire (51%) and from fragments of explosive devices (49%). Blast injury of the spinal cord was found in 10 patients. The most frequent complications caused by the fragments were wound infection, urinary tract infection, decubitus, and pneumonia. Four patients (4.2%) died in the hospital, and 43.0% of patients survived but were severely handicapped. CONCLUSION: Careful clinical examination combined with modern diagnostic imaging and use of broad-spectrum antibiotics reduced the need for surgical intervention in patients with spinal cord injuries.     

On the Expressiveness of Movement in Pure Mobile Ambients

Pure Mobile Ambients (i.e., Mobile Ambients without communication) provides three mobility primitives: in and out for ambient movement, and open to dissolve ambient boundaries. In this paper we consider the expressiveness of the primitives in and out for ambient movement; more precisely, we concentrate on the interplay between ambient movement and the ability to create new names (exploiting the restriction operator). To this aim, we consider a version of Pure Mobile Ambients (with explicit recursive definitions instead of replication) and we concentrate on the three fragments of the calculus that can be obtained removing either one or both between movement and the ability to create new names. The unique mobility primitive that we retain in all of the considered calculi is open. Te three fragments are denoted as follows: MA^−mv without ambient movement, MA_−v without restriction, and MA^−mv_−v without both movement and restriction. We prove that both the fragments MA^−mv and MA_−v are Turing-complete, while this is not the case for MA^−mv_−v. Indeed, we prove that in this latter calculus the existence of an infinite computation turns to be a decidable property.