25 research outputs found
In Vitro Evaluation of the Antiviral Potential of Guettarda angelica Against Animal Herpesviruses
Background: The number of antiviral studies using plant extracts has increased in the last decades, and the results have shown that plants are potential sources of compounds that are able to inhibit and/or decrease viral infections. The selection of these plants by ethnopharmacological criteria increases the probability of finding new substances with significant pharmacological and biological activities. Hence, Brazil has an advantage in this area due to its extensive biodiversity and ethnological diversity. Guettarda angelica is a plant from the Brazilian Caatinga region the roots of which are popularly used for various therapeutic purposes, including veterinary use. The aim of this work was to investigate the in vitro antiviral activity of extracts of plant parts from G. angelica against three animal herpesviruses: bovine (BoHV-1), suid (SuHV-1) and equine (EHV-1) herpesviruses type 1. Materials, Methods & Results: The extracts of roots, leaves and seeds of G. angelica were initially screened for in vitro antiviral activity against these herpesviruses using the virus yield reduction assay. The MDBK cells were used in assays with BoHV-1 and SuHV-1, and the Vero cells with EHV-1. For these assays, the cells previously treated with the extracts in non-cytotoxic concentrations were inoculated with logarithmic dilutions of each virus, The viral inhibitory activity of extracts was calculated by difference of virus titer between treated infected cells and non-treated infected cells. Only the aqueous extract from seeds (AEs) showed a significant antiviral activity (P < 0.01, ANOVA followed by Tukey test) against all herpesviruses leading continuous studies, Thus, the selectivity index (SI) of this extract was determined by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] colorimetric assay by calculating the ratio CC(50)over IC50. The 50% cytotoxic concentration (CC50) was defined as the extract concentration that reduced the cell viability by 50% when compared to untreated controls; the 50% inhibitory concentration (IC50) was defined as the concentration of the extract that inhibited 50% of viral replication when compared to the virus control. The CC50 and IC50 obtained from nonlinear regression analysis of concentration-effect curves by the GraphPad Prism 5 Demo program and represented the means +/- standard deviation of three independent experiments. The CC5(0) for Vero cells was 400.60 +/- 0.20 mu g/mL, while the CC50 for MDBK cells was 920.50 +/- 0.19 mu g/mL. The IC50 values of the AEs on the BoHV-1, SuHV-1 and EHV-1 were 22.79 mu g/mL, 91.30 mu g/mL and 19.95 mu g/mL, respectively. The SI values of this extract for each virus obtained from these data were 40.39, 10.08 and 20.08 for BoHV-1, SuHV-1, and EHV-1, respectively. Discussion: To ensure the antiviral activity of a plant extract and consequently its future use as antiviral agent is crucial the obtainment of its selectivity index or safety index. It is guarantee of a true antiviral effect and not the result of cytotoxicity of the extract on cells, and that could be confused with an antiviral activity. Other important point are the extract IC50 values less than 100 mu g/mL. The results of the AEs of G. angelica are in accordance with these considerations indicating that the Go angelica seeds may be a potential source of antiviral compounds insurance and encouraging further investigation of them.40
Understanding acute ankle ligamentous sprain injury in sports
This paper summarizes the current understanding on acute ankle sprain injury, which is the most common acute sport trauma, accounting for about 14% of all sport-related injuries. Among, 80% are ligamentous sprains caused by explosive inversion or supination. The injury motion often happens at the subtalar joint and tears the anterior talofibular ligament (ATFL) which possesses the lowest ultimate load among the lateral ligaments at the ankle. For extrinsic risk factors to ankle sprain injury, prescribing orthosis decreases the risk while increased exercise intensity in soccer raises the risk. For intrinsic factors, a foot size with increased width, an increased ankle eversion to inversion strength, plantarflexion strength and ratio between dorsiflexion and plantarflexion strength, and limb dominance could increase the ankle sprain injury risk. Players with a previous sprain history, players wearing shoes with air cells, players who do not stretch before exercising, players with inferior single leg balance, and overweight players are 4.9, 4.3, 2.6, 2.4 and 3.9 times more likely to sustain an ankle sprain injury. The aetiology of most ankle sprain injuries is incorrect foot positioning at landing – a medially-deviated vertical ground reaction force causes an explosive supination or inversion moment at the subtalar joint in a short time (about 50 ms). Another aetiology is the delayed reaction time of the peroneal muscles at the lateral aspect of the ankle (60–90 ms). The failure supination or inversion torque is about 41–45 Nm to cause ligamentous rupture in simulated spraining tests on cadaver. A previous case report revealed that the ankle joint reached 48 degrees inversion and 10 degrees internal rotation during an accidental grade I ankle ligamentous sprain injury during a dynamic cutting trial in laboratory. Diagnosis techniques and grading systems vary, but the management of ankle ligamentous sprain injury is mainly conservative. Immobilization should not be used as it results in joint stiffness, muscle atrophy and loss of proprioception. Traditional Chinese medicine such as herbs, massage and acupuncture were well applied in China in managing sports injuries, and was reported to be effective in relieving pain, reducing swelling and edema, and restoring normal ankle function. Finally, the best practice of sports medicine would be to prevent the injury. Different previous approaches, including designing prophylactice devices, introducing functional interventions, as well as change of games rules were highlighted. This paper allows the readers to catch up with the previous researches on ankle sprain injury, and facilitate the future research idea on sport-related ankle sprain injury
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Molecular Characterization of Brazilian Infectious Bursal Disease Virus Isolated from 1997 to 2005
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This retrospective study concerned 41 infectious bursal disease virus (IBDV) isolates obtained from Brazilian broiler and layers flocks by reverse transcription-polymerase chain reaction. Twenty-five of them were identified as very virulent (vv) by restriction enzyme analysis and by further nucleotide and phylogenetic analysis. All of them had the typical amino acid residues, and all clustered in a phylogenetic tree with the vvIBDV strains. Four amino acid substitutions, at positions D213N, G254D, S317R, and D323E, were common to 3 vv isolates, Br/03/DB, Br/03/CK, and Br/04/CR, and differed from other vv isolates and strains. These isolates came from the same locale, but were collected in different years, indicating that the vvIBDVs circulating on Brazilian farms are undergoing slight but continuous exchanges.533449454Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [02/10110-3
Routing of Highly Anisotropic Spatial Solitons and Modulational Instability in liquid crystals
In certain materials, the spontaneous spreading of a laser beam ( owing to diffraction) can be compensated for by the interplay of optical intensity and material nonlinearity. The resulting nondiffracting beams are called 'spatial solitons' (refs 1 - 3), and they have been observed in various bulk media(4-6). In nematic liquid crystals(7-9), solitons can be produced at milliwatt power levels(10-12) and have been investigated for both practical applications(13) and as a means of exploring fundamental aspects of light interactions with soft matter(14,15). Spatial solitons effectively operate as waveguides, and so can be considered as a means of channelling optical information along the self-sustaining filament. But actual steering of these solitons within the medium has proved more problematic, being limited to tilts of just a fraction of a degree(16-20). Here we report the results of an experimental and theoretical investigation of voltage-controlled 'walk-off' and steering of self-localized light in nematic liquid crystals. We find not only that the propagation direction of individual spatial solitons can be tuned by several degrees, but also that an array of direction-tunable solitons can be generated by modulation instability(21-25). Such control capabilities might find application in reconfigurable optical interconnects, optical tweezers and optical surgical techniques