Indirect detection of an epitope-specific response to HIV-1 gp120 immunization in human subjects

A specific response of human serum neutralizing antibodies (nAb) to a conformational epitope as a result of vaccination of human subjects with the surface envelope glycoprotein (gp120) of HIV-1 has not previously been documented. Here, we used computational analysis to assess the epitope-specific responses of human subjects, which were immunized with recombinant gp120 immunogens in the VAX003 and VAX004 clinical trials. Our computational methodology--a variation of sieve analysis--compares the occurrence of specific nAb targeted conformational 3D epitopes on viruses from infected individuals who received vaccination to the occurrence of matched epitopes in the viruses infecting placebo subjects. We specifically studied seven crystallographically defined nAb targeted conformational epitopes in the V3 loop, an immunogenic region of gp120. Of the six epitopes present in the immunogens and targeted by known monoclonal neutralizing antibodies, only the one targeted by the anti-V3 nAb 2219 exhibited a significant reduction in occurrence in vaccinated subjects compared to the placebo group. This difference occurred only in the VAX003 Thailand cohort. No difference was seen between vaccinated and placebo groups for the occurrence of an epitope that was not present in the immunogen. Thus, it can be theorized that a specific 2219-like human neutralizing antibody immune response to AIDSVAX immunization occurred in the VAX003 cohort, and that this response protected subjects from a narrow subset of HIV-1 viruses circulating in Thailand in the 1990s and bearing the conformational epitope targeted by the neutralizing antibody 2219.     

Should we abandon Kielland's forceps?

To assess the risks associated with the use of Kielland''s forceps 2708 consecutive deliveries were studied prospectively and the neonatal outcome related to the mode of delivery. Of the 1191 primigravidas, 279 (23.4%) underwent instrumental delivery, of whom 65 (5.5%) were delivered with Kielland''s forceps. There was no difference in early neonatal outcome (as judged by Apgar scores, intubations, and admission to the special care baby unit) between these babies and those delivered normally or by non-rotational forceps, but a higher proportion of the 127 (10.7%) delivered by emergency caesarean section were compromised. Of the 1517 multigravid patients, only 57 (3.8%) underwent instrumental delivery, 15 (1.0%) by Kielland''s forceps. Among these babies, also, the outcome was no worse than for those delivered normally, but the babies delivered by caesarean section showed a greatly increased incidence of low Apgar scores, intubations, and admission to the special care baby unit. There were no stillbirths or neonatal deaths among babies delivered by Kielland''s forceps, nor were there any cases of severe birth trauma or of obvious neonatal morbidity.     

Gibberellin like Substances in Parts of Developing Barley Grain

In husks, the activity of gibberellin-like substances extracted with aqueous methanol (M-“free” GAs) showed a maximum on the 9th day after pollination. In developing embryos, M-“free” GAs showed no biological activity, whereas biological active component(s) were obtained when the embryos were extracted with Tris buffer. The “free” GAs found in the buffer homogenates (B-“free” GAs) of developing embryos showed a maximum of activity on the 33rd day after pollination. Bound GAs recovered from the precipitated protein of the buffer homogenate (“Protein-bound” GAs) were found in embryo and endosperm. Developing endosperm generally contains the major amount of the extractable gibberellin-like substances. In this tissue, the amount of all examined fractions (M-“free” GAs, B-“free” GAs and “protein-bound” GAs) increased after pollination to reach a maximum on the 21st day, before decreasing to a minimum at grain maturity. Moreover, the curves for dry weight increase and gibberellin like substances follow a remarkably similar course, with the latter reaching its maximim slightly earlier than the former one. This result indicates that gibberellines may participate in the regulation of the accumulation process in the endosperm of barley grain.     

Genetic diversity of the rain tree (Albizia saman) in Colombian seasonally dry tropical forest for informing conservation and restoration interventions

Albizia saman is a multipurpose tree species of seasonally dry tropical forests (SDTFs) of Mesoamerica and northern South America typically cultivated in silvopastoral and other agroforestry systems around the world, a trend that is bound to increase in light of multimillion hectare commitments for forest and landscape restoration. The effective conservation and sustainable use of A. saman requires detailed knowledge of its genetic diversity across its native distribution range of which surprisingly little is known to date. We assessed the genetic diversity and structure of A.saman across twelve representative locations of SDTF in Colombia, and how they may have been shaped by past climatic changes and human influence. We found four different genetic groups which may be the result of differentiation due to isolation of populations in preglacial times. The current distribution and mixture of genetic groups across STDF fragments we observed might be the result of range expansion of SDTFs during the last glacial period followed by range contraction during the Holocene and human‐influenced movement of germplasm associated with cattle ranching. Despite the fragmented state of the presumed natural A. saman stands we sampled, we did not find any signs of inbreeding, suggesting that gene flow is not jeopardized in humanized landscapes. However, further research is needed to assess potential deleterious effects of fragmentation on progeny. Climate change is not expected to seriously threaten the in situ persistence of A. saman populations and might present opportunities for future range expansion. However, the sourcing of germplasm for tree planting activities needs to be aligned with the genetic affinity of reference populations across the distribution of Colombian SDTFs. We identify priority source populations for in situ conservation based on their high genetic diversity, lack or limited signs of admixture, and/or genetic uniqueness.     

Redescription and molecular identification of Isospora feroxis Berto,Luz, Flausino,Ferreira & Lopes, 2009 (Eimeriidae) from tyrant-flycatchers (Tyrannoidea) in South America

Systematic Parasitology - In the present study Isospora feroxis Berto, Luz, Flausino, Ferreira & Lopes, 2009 is redescribed from the photosyntypes and from new samples from a short-crested...     

Identification and analysis of PH domain-containing targets of phosphatidylinositol 3-kinase using a novel in vivo assay in yeast.

Phosphatidylinositol 3-kinase (PI3K) mediates a variety of cellular responses by generating PtdIns(3,4)P2 and PtdIns(3,4,5)P3. These 3-phosphoinositides then function directly as second messengers to activate downstream signaling molecules by binding pleckstrin homology (PH) domains in these signaling molecules. We have established a novel assay in the yeast Saccharomyces cerevisiae to identify proteins that bind PtdIns(3,4)P2 and PtdIns(3,4,5)P3 in vivo which we have called TOPIS (Targets of PI3K Identification System). The assay uses a plasma membrane-targeted Ras to complement a temperature-sensitive CDC25 Ras exchange factor in yeast. Coexpression of PI3K and a fusion protein of activated Ras joined to a PH domain known to bind PtdIns(3,4)P2 (AKT) or PtdIns(3,4,5)P3 (BTK) rescues yeast growth at the non-permissive temperature of 37 degreesC. Using this assay, we have identified several amino acids in the beta1-beta2 region of PH domains that are critical for high affinity binding to PtdIns(3,4)P2 and/or PtdIns(3,4,5)P3, and we have proposed a structural model for how these PH domains might bind PI3K products with high affinity. From these data, we derived a consensus sequence which predicts high-affinity binding to PtdIns(3, 4)P2 and/or PtdIns(3,4,5)P3, and we have identified several new PH domain-containing proteins that bind PI3K products, including Gab1, Dos, myosinX, and Sbf1. Use of this assay to screen for novel cDNAs which rescue yeast at the non-permissive temperature should provide a powerful approach for uncovering additional targets of PI3K.     

Effect of Chronic Treatment with Conventional and Organic Purple Grape Juices (Vitis labrusca) on Rats Fed with High-Fat Diet

Serra Gaucha is described as the most important wine region of Brazil. Regarding cultivars widespread in the Serra Gaucha, about 90 % of the area is occupied by vines of Vitis labrusca that is the most important specie used in grape juice production. The objective of this study was to investigate the antioxidant and neuroprotective effect of chronic intake of purple grape juice (organic and conventional) from Bordo variety (V. labrusca) on oxidative stress in different brain regions of rats supplemented with high-fat diet (HFD) for 3 months. A total of 40 male rats were randomly divided into 4 groups. Group 1 received a standard diet and water, group 2 HFD and water, group 3 HFD and conventional grape juice (CGJ), and group 4 HFD and organic grape juice (OGJ). All groups had free access to food and drink and after 3 months of treatment the rats were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum isolated and homogenized on ice for oxidative stress analysis. We observed that the consumption of calories in HFD and control groups, were higher than the groups supplemented with HFD and grape juices and that HFD diet group gain more weight than the other animals. Our results also demonstrated that HDF enhanced lipid peroxidation (TBARS) and protein damage (carbonyl) in cerebral cortex and hippocampus, reduced the non-enzymatic antioxidants defenses (sulfhydryl) in cerebral cortex and cerebellum, reduced catalase and superoxide dismutase activities in all brain tissues and enhanced nitric oxide production in all cerebral tissues. CGJ and OGJ were able to ameliorate these oxidative alterations, being OGJ more effective in this protection. Therefore, grape juices could be useful in the treatment of some neurodegenerative diseases associated with oxidative damage.