SUMMARYWe have developed a solid-phase enzyme-linked immunosorbent assay (ELISA) to study the vaccination responses to Vi capsular polysaccharide of Salmonella typhi ( S. typhi Vi ) vaccine. Purified S. typhi Vi polysaccharide was biotinylated and bound to streptavidin coated microtitre plates. Reproducibility was determined across a range of IgG antibody levels: mean interassay coefficients of variation (CVs) were < 11·9% for non-vaccinated sera with low levels and < 11·1% for sera with very high levels of anti-S. typhi Vi IgG. Specificity was assessed by inhibition studies using salmonella antigen. We have developed the ELISA based on normal adult serum responses to test immunization with S. typhi Vi vaccine. We also report here anti-S. typhi Vi IgG levels in a group of healthy preschool children. In nonvaccinated adult sera ( n = 104), the median value of anti -S. typhi Vi IgG, expressed in S. typhi Vi arbitrary units (AU/ml), was 5·3 AU/ml and in non-vaccinated sera from children ( n = 44) the median value was 1·4 AU/ml. The data from immunization of healthy volunteers ( n = 23) show that geometric mean levels of anti-S. typhi Vi IgG were significantly higher ( P < 0·0001) for post-vaccination subjects (39·2 AU/ml) compared to paired prevaccination (3·9 AU/ml) values. A total of 21/23 vaccine recipients had < 8 AU/ml S. typhi Vi IgG in their sera prior to vaccination and of these 20/21 (95%) exhibited threefold increases and 14/21 (67%) fourfold increases in their S. typhi Vi IgG following vaccination. Based on the data in this study, we propose a threefold increase in anti-S. typhi Vi IgG post-vaccination to be considered a positive vaccination response. The ability to demonstrate clearly an antibody rise in response to immunization with S. typhi Vi capsular polysaccharide vaccine suggests that this is likely to be a useful vaccine for the assessment of B cell function in patients with suspected immune deficiency.
The marine brown alga Dictyota pfaffii from Atol das Rocas, in Northeast Brazil is a rich source of dolabellane diterpene, which has the potential to be used in future antiviral drugs by inhibiting reverse transcriptase (RT) of HIV-1. Reexamination of the minor diterpene constituents yielded three new dolabellane diterpenes, (1R*,2E,4R*,7S,10S*,11S*,12R*)10,18-diacetoxy-7-hydroxy-2,8(17)-dolabelladiene (1), (1R*,2E,4R*,7R*,10S*,11S*,12R*)10,18-diacetoxy-7-hydroxy-2,8(17)-dolabelladiene (2), (1R*,2E,4R*,8E,10S*,11S,12R*)10,18-diacetoxy-7-hydroxy-2,8-dolabelladiene (3), termed dolabelladienols A–C (1–3) respectively, in addition to the known dolabellane diterpenes (4–6). The elucidation of the compounds 1–3 was assigned by 1D and 2D NMR, MS, optical rotation and molecular modeling, along with the relative configuration of compound 4 and the absolute configuration of 5 by X-ray diffraction. The potent anti-HIV-1 activities displayed by compounds 1 and 2 (IC50 = 2.9 and 4.1 μM), which were more active than even the known dolabelladienetriol 4, and the low cytotoxic activity against MT-2 lymphocyte tumor cells indicated that these compounds are promising anti-HIV-1 agents.
Since human beings have sought in nature, components that can obtain help in therapeutics or even in the cure of diseases. The progress made in the area of science promoted the development of recognized and effective herbal medicines, as well as the search for the population, for less aggressive treatments. The evaluation of the antioxidant activity of plants has been an important issue taking into account its importance on human health, since the natural antioxidants present a reduced health risk, when compared to the synthetic ones that present toxic effect. From the Asteraceae family, of which the plant species Taraxacum officinale, popularly known as dandelion, stands out among the 71 species on the list of the Ministry of Health (RENISUS), scientifically affirmed, to treat liver disorders, inflammations, potential in the anti-bacterial, cytotoxic, antiviral, antiparasitic, antifungal activity, besides studies to verify its anticancer action and of carcinogenic prevention. The acute toxicity of Taraxacum officinale appears to be low, with LD50 values estimated at 36.8g / kg and 28.8g / kg, for the whole plant. The adverse or complex toxic effects for T. officinale have not yet been reported. This review of the literature was elaborated through studies of articles contained in the Scielo, Google Scholar and Pub Med platforms. Through this review the importance of phytotherapy studies for pharmacological purposes was verified, aiming to improve the therapeutics.
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