New therapeutic approaches are necessary to control strongyloidiasis due to the side effects of, and resistance to, currently available drugs thiabendazole, albendazole, and ivermectin. This study examined the anthelmintic properties of extracts and isolated compounds from Siparuna guianensis against Strongyloides venezuelensis eggs and larvae, using the egg hatching test (EHT) and larval motility test (LMT). Albendazole (0.025 mg/ml) and ivermectin (0.316 mg/ml) were used as the positive controls for the EHT and LMT assays, respectively. Strongyloides venezuelensis eggs or larvae (±50 specimens) were treated with ethanol extract (0.05–1.0 mg/ml), ethyl acetate and aqueous fractions (0.05–0.8 mg/ml), essential oil (0.2–1.0 mg/ml) and α-bisabolol (0.2–1.0 mg/ml) from S. guianensis, and analysed by optical microscopy after 48 h (EHT), or after 24, 48 and 72 h (LMT). All the tested compounds exhibited ovicidal activity equivalent to the positive control and changed the morphology of the eggs. The S. guianensis ethanol extract and aqueous fraction were as effective as the positive control. Phytochemical analysis of the ethanol extract and fractions revealed the presence of phenolic compounds, tannins and flavonoids. Therefore, S. guianensis is effective against S. venezuelensis eggs and larvae in vitro, and can be considered as a potential alternative treatment for strongyloidiasis.
Non-biological ornamentation is found in the nests and burrows of different kinds of animals. We evaluated here whether sand hoods constructed by male fiddler crabs (Uca leptodactyla) are one of the signals used by males to attract females during courtship. We observed females when they were walking among the males, and we quantified the proportion of females that visited male burrows with and without ornamentation and the choice to stay in a male's burrow. Females visited more burrows with hoods than burrows without hoods, and they chose significantly more builder males. Male investment in ornamentation nevertheless decreased when the proportion of females increased in the area. Male investment was not correlated with the proportion of non-builder males nearby, but was positively correlated with overall density. The density sex ratio, however, was more male-biased in high-density than in low-density areas suggesting that even if building attracts females, the function could be related to male competition for mates.
In this study we evaluated the types of algae chosen for decorating by the spider crabAcanthonyx scutiformis(Dana, 1851) and determined whether decorating is more common in juvenile or adult crabs and in females or males (adult). In field observations we found that spider crabs in each age group or sex have an equal probability of being decorated. There were no differences in this behaviour between sexes in the laboratory. However, juvenile spider crabs engaged more in decoration behaviour than adult crabs in laboratory observations and decorated with the same algae that they used for decorating in nature. Thus, in conditions that represent an increased risk of predation, juvenile crabs have an increased need to attach algal fragments onto their carapaces, whereas the body size of adult spider crabs renders them less vulnerable to predators, thus reducing their need for decoration.
In 25 patients with cysticercosis of central nervous system, classified in two clinical forms, benign and malign, evoked potentials were obtained. Normal exam was found in 9 cases with the benign form. From 4 patients with malign clinical presentations, 2 had multiple abnormalities of the evoked potentials, and F wave alterations (mixed pattern). The authors suggest that this mixed pattern may be indicative of severe prognosis.
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