Effect of the lectin of Bauhinia variegata and its recombinant isoform on surgically induced skin wounds in a murine model

Lectins are a structurally heterogeneous group of highly specific carbohydrate-binding proteins. Due to their great biotechnological potential, lectins are widely used in biomedical research. The purpose of the present study was to evaluate the healing potential of the lectin of Bauhinia variegata (nBVL) and its recombinant isoform (rBVL-1). Following surgical creation of dorsal skin wounds, seven groups of mice were submitted to topical treatment for 12 days with lectin, D-galactose, BSA and saline. The animals were anesthetized and euthanized on POD 2, 7 and 12 in order to evaluate the healing potential of each treatment. The parameters considered included wound size, contraction rate, epithelialization rate and histopathological findings. Wound closure was fastest in animals treated with rBVL-1 (POD 7). nBVL was more effective than the controls. All skin layers were reconstructed and keratin deposition increased. Our findings indicate that the lectin of Bauhinia variegata possesses pro-healing properties and may be employed in the treatment of acute skin wounds.     

Electronic properties of Fibonacci and random Si-Ge chains

In this paper we address a theoretical calculation of the electronic spectra of an Si-Ge atomic chain that is arranged in a Fibonacci quasi-periodic sequence, by using a semi-empirical quantum method based on the Hückel extended model. We apply the Fibonacci substitutional sequences in the atomic building blocks A(Si) and B(Ge) through the inflation rule or a recursion relation. In our ab initio calculations we use only a single point, which is sufficient for considering all the orbitals and charge distribution across the entire system. Although the calculations presented here are more complete than the models adopted in the literature which take into account the electronic interaction only up to the second and third neighbors, an interesting property remains in their electronic spectra: the fractality (which is the main signature of this kind of system). We discuss this fractality of the spectra and we compare them with the random arrangement of the Si-Ge atomic chain, and with previous results based on the tight-binding approximation of the Schr?dinger equation considering up to the nearest neighbor.     

Development and single laboratory validation of an optical biosensor assay for tetrodotoxin detection as a tool to combat emerging risks in European seafood

Tetrodotoxin (TTX) is a potent neurotoxin emerging in European waters due to increasing ocean temperatures. Its detection in seafood is currently performed as a consequence of using the Association of Analytical Communities (AOAC) mouse bioassay (MBA) for paralytic shellfish poisoning (PSP) toxins, but TTX is not monitored routinely in Europe. Due to ethical and performance-related issues associated with this bioassay, the European Commission has recently published directives extending procedures that may be used for official PSP control. An AOAC-accredited high-performance liquid chromatography (HPLC) method has now been accepted by the European Union as a first action screening method for PSP toxins to replace the MBA. However, this AOAC HPLC method is not capable of detecting TTX, so this potent toxin would be undetected; thereby, a separate method of analysis is required. Surface plasmon resonance (SPR) optical biosensor technology has been proven as a potential alternative screening method to detect PSP toxins in seafood. The addition of a similar SPR inhibition assay for TTX would complement the PSP assay in removing the MBA. The present report describes the development and single laboratory validation in accordance with AOAC and IUPAC guidelines of an SPR method to be used as a rapid screening tool to detect TTX in the sea snail Charonia lampas lampas, a species which has been implicated in 2008 in the first case of human TTX poisoning in Europe. As no current regulatory limits are set for TTX in Europe, single laboratory validation was undertaken using those for PSP toxins at 800 μg/kg. The decision limit (CCα) was 100 μg/kg, with the detection capability (CCβ) found to be ≤200 μg/kg. Repeatability and reproducibility were assessed at 200, 400, and 800 μg/kg and showed relative standard deviations of 8.3, 3.8, and 5.4 % and 7.8, 8.3, and 3.7 % for both parameters at each level, respectively. At these three respective levels, the recovery of the assay was 112, 98, and 99 %.     

Diffusive-Ballistic Transition in Random Polymers with Drift and Repulsive Long-Range Interactions

In this note phase transition issues are addressed for random polymers on \(\mathbb {Z}^2\) with long-range self-repulsive interactions. It is shown that, in the absence of drift and with power law interactions, the polymer exhibits transition from diffusive to a ballistic behavior. When non-null drifts are added and positive translation invariant interactions are considered, the polymer presents a ballistic behavior. Our results complement some previous studies on the matter and we also derive a Central Limit Theorem for the model.     

A Study of the Effects of Aeration and Agitation on the Properties and Production of Xanthan Gum from Crude Glycerin Derived from Biodiesel Using the Response Surface Methodology

The effects of aeration and agitation on the properties and production of xanthan gum from crude glycerin biodiesel (CGB) by Xanthomonas campestris mangiferaeindicae 2103 were investigated and optimized using a response surface methodology. The xanthan gum was produced from CGB in a bioreactor at 28 °C for 120 h. Optimization procedures indicated that 0.97 vvm at 497.76 rpm resulted in a xanthan gum production of 5.59 g L^?1 and 1.05 vvm at 484.75 rpm maximized the biomass to 3.26 g L^?1. Moreover, the combination of 1.05 vvm at 499.40 rpm maximized the viscosity of xanthan at 0.5 % (m/v), 25 °C, and 25 s^?1 (255.40 mPa s). The other responses did not generate predictive models. Low agitation contributed to the increase of xanthan gum production, biomass, viscosity, molecular mass, and the pyruvic acid concentration. Increases in the agitation contributed to the formation of xanthan gum with high mannose concentration. Decreases in the aeration contributed to the xanthan gum production and the formation of biopolymer with high mannose and glucose concentrations. Increases in aeration contributed to increased biomass, viscosity, and formation of xanthan gum with greater resistance to thermal degradation. Overall, aeration and agitation of CGB fermentation significantly influenced the production of xanthan gum and its properties.     

Application of SPME to the determination of alkylphenols and bisphenol A in cyanobacteria culture media

In order to survey the influence of estrogenic compounds on cyanobacteria, solid-phase microextraction (SPME) with a carbowax-divinylbenzene fibre was used for the determination of tert-octylphenol (tert-OP), n-nonylphenol (n-NP), technical nonylphenol (tech-NP) and bisphenol A (BPA) in cyanobacteria culture media by gas chromatography with flame ionization detection. Determinations were carried out without derivatization in deionized water and filtered culture media. A comparison between f2 and Fraquil culture media was performed, which showed that only f2 allowed quantitative recoveries. Headspace SPME with salting out, requiring only 10 mL of sample, was suitable for tert-OP, n-NP, and tech-NP determination with limits of detection (LOD) of <0.05 μg L⁻¹. For BPA, direct immersion SPME could provide a LOD of 1 μg L⁻¹. Automated sampling allowed reproducible extraction. No exudate substances overlapped with the studied compounds during the chromatographic separation and no matrix effects were observed. Ecotoxicity tests can be performed by single spiking of tert-OP and tech-NP and multiple spiking of n-NP due to its lower stability.     

Effects of low-level laser irradiation in ultrastructural morphology, and immunoexpression of VEGF and VEGFR-2 of rat masseter muscle

The present study evaluates by ultrastructural and immunohistochemical methods, the possible changes on muscular tissue affected by LLLI during a treatment, for example, in cases of temporomandibular joint disorders. Sixty male Wistar rats divided into 6 groups (n=10) received ten laser irradiations, with different energy densities (groups I-0; II-0.5; III-1.0; IV-2.5; V-5.0; and VI-20 J/cm(2)). Muscles were removed and processed for transmission electron microscopic and immunohistochemical (VEGF and VEGFR-2) analyses. Captured photomicrographs of immunohistochemistry and transmission electron microscopy were evaluated. It was observed in the irradiated muscles, mitochondria of different shapes and sizes, with increased plasticity evidenced by organelles in fusion, division and the presence of elongated structures with characteristics of mitochondria, proximity with the dilated sarcoplasmatic reticulum, suggesting organelles with large amounts of energy, and the presence of cytoplasmic protrusions in the capillaries with high dosages. All studied groups showed immunostainings for both markers (VEGF and VEGFR-2), but in general those who received higher doses also showed the markings more pronounced, suggesting dose-dependent biomodulation. It was concluded that the LLLI was able to modify the ultrastructural characteristics and immunohistochemical pattern of VEGF and VEGFR-2 in the masseter muscle of rats.     

Phenolic Compounds’ Occurrence in Opuntia Species and Their Role in the Inflammatory Process: A Review

Within the Cactaceae family, Opuntia comprises the most widespread species, with a recognized importance in human life, including feeding, domestic use as home natural barriers, and as a traditional remedy for diverse diseases and conditions such asthma, edema, and burns. Indeed, scientific reports have stated that these health benefits may be due to various active compounds, particularly polyphenols, which are ubiquitously found in plants and have proven their pharmacological efficiency by displaying antimicrobial, anti-cancer, and anti-inflammatory activities, among others. Opuntia species contain different classes of phenolic compounds that are recognized for their anti-inflammatory potential. Among them, quercetin, isorhamnetin, and kaempferol derivates were reported to greatly contribute to modulate cells’ infiltration and secretion of soluble inflammatory mediators, with key implications in the inflammatory process. In this review, we make a summary of the different classes of phenolic compounds reported in Opuntia species so far and explore their implications in the inflammatory process, reported by in vitro and in vivo bioassays, supporting the use of cactus in folk medicine and valorizing them from the socio-economic point of view.     

Use of Piranha Solution as An Alternative Route to Promote Bioactivation of PEEK Surface with Low Functionalization Times

This study aimed to achieve bioactivity on the PEEK surface using piranha solution through a lower functionalization time. For this purpose, the functionalization occurred with piranha solution and 98% sulfuric acid in the proportions of 1:2, 1:1, and 2:1 at periods of 30, 60, and 90 s. The samples treated for longer times at higher concentrations registered the characteristic spectroscopy band associated with sulfonation. Additionally, both chemical treatments allowed the opening of the aromatic ring, increasing the number of functional groups available and making the surface more hydrophilic. The piranha solution treatments with higher concentrations and longer times promoted greater heterogeneity in the surface pores, which affected the roughness of untreated PEEK. Furthermore, the treatments induced calcium deposition on the surface during immersion in SBF fluid. In conclusion, the proposed chemical modifications using sulfuric acid SPEEK 90 and, especially, the piranha solution PEEK-PS 2:1-90, were demonstrated to be promising in promoting the rapid bioactivation of PEEK-based implants.