Antioxidant Effects of Quercetin and Catechin Encapsulated into PLGA Nanoparticles

Polymeric nanoparticles (PLGA) have been developed for the encapsulation and controlled release of quercetin and catechin. Nanoparticles were fabricated using a solvent displacement method. Physicochemical properties were measured by light scattering, scanning electron microscopy and ζ-potential, X-ray diffraction, infrared spectroscopy and differential scanning calorimetry. Encapsulation efficiency and in vitro release profiles were obtained from differential pulse voltammetry experiments. Antioxidant properties of free and encapsulated flavonoids were determined by TBARS, fluorescence spectroscopy and standard chelating activity methods. Relatively small (d≈ 400 nm) polymeric nanoparticles were obtained containing quercetin or catechin in a non-crystalline form (EE ≈ 79%) and the main interactions between the polymer and each flavonoid were found to consist of hydrogen bonds. In vitro release profiles were pH-dependant, the more acidic pH, the faster release of each flavonoid from the polymeric nanoparticles. The inhibition of the action of free radicals and chelating properties, were also enhanced when quercetin and catechin were encapsulated within PLGA nanoparticles. The information obtained from this study will facilitate the design and fabrication of polymeric nanoparticles as possible oral delivery systems for encapsulation, protection and controlled release of flavonoids aimed to prevent oxidative stress in human body or food products

Antitumor and immunostimulatory activities of a genotype V recombinantattenuated veterinary Newcastle disease virus vaccine

"Antitumor conventional treatments including chemo/radiotherapy result in several side effects and non-specificity. Therapies including the use of oncolytic viruses, particularly the Newcastle disease virus (NDV), have emerged as an attractive alternative due to their capacity to kill cancer cells directly or through stimulation of the immune system. In the present study, a commercial vaccine composed of a recombinant attenuated NDV strain P05 (rNDV-P05) was assessed for antitumor and immunostimulatory activity. Firstly, hemagglutination activity was evaluated at different pH and temperature conditions. Then, cancer cell lines and peripheral blood mononuclear cells (PBMC) were co-cultured with or without rNDV-P05 and cytoplasmic nucleosomes were measured by enzyme-linked immunosorbent assay (ELISA) as an apoptosis indicator. Antitumor cytokines produced by PBMC in response to the virus were analyzed by ELISA and reverse transcription quantitative polymerase chain reaction. Characterization ofrNDV-P05 indicates that the virus is slightly sensible to acid and basic pH, and stable at temperatures no greater than 42 degrees C. The majority of cell lines developed apoptosis in co-culture with rNDV-P05 in a dose-time dependent manner. The highest level of HeLa, HCC1954 and HepG2 cell apoptosis was at 48 h/50 hemagglutination units (HU), and HL-60 was 24 h/50 HU.A549 cell line and PBMC did not show sensitivity to apoptosis by the virus. PBMC from healthy donors stimulated with the rNDV-P05 increased significantly the levels of interferon (IFN)-alpha, IFN-gamma, tumor necrosis factor (TNF)-alpha and soluble TNF-related apoptosis-inducing I igand in culture supernatants, as well as their mRNA expression. These results demonstrate that the pro-apoptotic effect ofrNDV-P05 and its magnitude is specific to particular tumor cell lines and is not induced on PBMC; and the virusstimulates the expression of several key antitumor cytokines. This study promotes the use of rNDV-P05 in an alternate application of different viral strains during virotherapy with NDV.

Source characteristics of a 5.5 magnitude earthquake that occurred in the transform fault system

Abstract Portable and permanent broadband seismic stations in the neighborhood of the Gulf of California recorded a moment magnitude M w 5.5 event on 26 November 1997. This is the first time that a moderate event located in the Gulf of California extensional province was well recorded by local broadband seismic stations. The event was located at 29.754Њ N and 113.708Њ W and at a focal depth of 5.0 km in the southeastern end of the transform fault that connects the lower and upper Delfin basins. The hypocentral location and the results of the wave modeling indicate that this is a complex event that originated in the pull-apart Delfin basin. The focal mechanism estimated from first motions ( ‫ס‬ 310Њ, d ‫ס‬ 83Њ, k ‫ס‬ 97Њ) and body-wave modeling of P waves in the frequency band 0.05-0.5 Hz suggests that the rupture started with dip-slip (reverse faulting) motion and ended releasing the bulk of energy through strike-slip motion. Synthetics of surface waves in the frequency band 0.05-0.1 Hz were also calculated using a triangular source-time function of 3 sec. The best match between the synthetics and observed surface waves recorded at 90 km from the epicenter was obtained using a fault geometry defined by a strike of 330Њ ‫ע‬ 15, dip 85Њ ‫ע‬ 5, and slip of 165Њ ‫ע‬ 15. The spectral analysis of the Lg phase recorded at stations in the Peninsular Ranges gives a seismic moment of 1.28 ‫ן‬ 10 17 N m (1.28 ‫ן‬ 10 24 dyne cm), a source radius of 6.3 km and a stress drop of 0.22 MPa (2.2 bar). The source parameters inferred with S-wave spectra and the same mode

Prostate response to prolactin in sexually active male rats

BACKGROUND: The prostate is a key gland in the sexual physiology of male mammals. Its sensitivity to steroid hormones is widely known, but its response to prolactin is still poorly known. Previous studies have shown a correlation between sexual behaviour, prolactin release and prostate physiology. Thus, here we used the sexual behaviour of male rats as a model for studying this correlation. Hence, we developed experimental paradigms to determine the influence of prolactin on sexual behaviour and prostate organization of male rats. METHODS: In addition to sexual behaviour recordings, we developed the ELISA procedure to quantify the serum level of prolactin, and the hematoxilin-eosin technique for analysis of the histological organization of the prostate. Also, different experimental manipulations were carried out; they included pituitary grafts, and haloperidol and ovine prolactin treatments. Data were analyzed with a One way ANOVA followed by post hoc Dunnet test if required. RESULTS: Data showed that male prolactin has a basal level with two peaks at the light-dark-light transitions. Consecutive ejaculations increased serum prolactin after the first ejaculation, which reached the highest level after the second, and started to decrease after the third ejaculation. These normal levels of prolactin did not induce any change at the prostate tissue. However, treatments for constant elevations of serum prolactin decreased sexual potency and increased the weight of the gland, the alveoli area and the epithelial cell height. Treatments for transient elevation of serum prolactin did not affect the sexual behaviour of males, but triggered these significant effects mainly at the ventral prostate. CONCLUSION: The prostate is a sexual gland that responds to prolactin. Mating-induced prolactin release is required during sexual encounters to activate the epithelial cells in the gland. Here we saw a precise mechanism controlling the release of prolactin during ejaculations that avoid the detrimental effects produced by constant levels. However, we showed that minor elevations of prolactin which do not affect the sexual behaviour of males, produced significant changes at the prostate epithelium that could account for triggering the development of hyperplasia or cancer. Thus, it is suggested that minute elevations of serum prolactin in healthy subjects are at the etiology of prostate abnormal growth

Pixel-Wise Classification in Hippocampus Histological Images

This paper presents a method for pixel-wise classification applied for the first time on hippocampus histological images. The goal is achieved by representing pixels in a 14-D vector, composed of grey-level information and moment invariants. Then, several popular machine learning models are used to categorize them, and multiple metrics are computed to evaluate the performance of the different models. The multilayer perceptron, random forest, support vector machine, and radial basis function networks were compared, achieving the multilayer perceptron model the highest result on accuracy metric, AUC, and F1 score with highly satisfactory results for substituting a manual classification task, due to an expert opinion in the hippocampus histological images

Leuprolide acetate induces structural and functional recovery of injured spinal cord in rats

Gonadotropin-releasing hormone (GnRH) and its synthetic analog leuprolide acetate, a GnRH agonist, have neurotrophic properties. This study was designed to determine whether administration of leuprolide acetate can improve locomotor behavior, gait, micturition reflex, spinal cord morphology and the amount of microglia in the lesion epicenter after spinal cord injury in rats. Rats with spinal cord compression injury were administered leuprolide acetate or saline solution for 5 weeks. At the 5 th week, leuprolide acetate-treated rats showed locomotor activity recovery by 38%, had improvement in kinematic gait and exhibited voiding reflex recovery by 60%, as compared with the 1 st week. By contrast, saline solution-treated rats showed locomotor activity recovery only by 7%, but voiding reflex did not recover. More importantly, leuprolide acetate treatment reduced microglial immunological reaction and induced a trend towards greater area of white and gray matter in the spinal cord. Therefore, leuprolide acetate has great potential to repair spinal cord injury