Molecular modeling studies demonstrate key mutations that could affect the ligand recognition by influenza AH1N1 neuraminidase

Journal of Molecular Modeling - There is a wide variety of ion channel types with various types of blockers, making research in this field very complicated. To reduce this complexity, it is...     

IFN-γ Production to Leishmania Antigen Supplements the Leishmania Skin Test in Identifying Exposure to L. braziliensis Infection

Background

Cutaneous leishmaniasis due to L. braziliensis (CL) is characterized by a positive delayed type hypersensitivity test (DTH) leishmania skin test (LST) and high IFN-γ production to soluble leishmania antigen (SLA). The LST is used for diagnosis of CL and for identification of individuals exposed to leishmania infection but without disease. The main aim of the present study was to identify markers of exposure to L. braziliensis infection.

Methodolgy/Principal Findings

This cohort study enrolled 308 household contacts (HC) of 76 CL index cases. HC had no active or past history of leishmaniasis. For the present cross-sectional study cytokines and chemokines were determined in supernatants of whole blood culture stimulated with SLA. Of the 308 HC, 36 (11.7%) had a positive LST but in these IFN-γ was only detected in 22 (61.1%). Moreover of the 40 HC with evidence of IFN-γ production only 22 (55%) had a positive LST. A total of 54 (17.5%) of 308 HC had specific immune response to SLA. Only a moderate agreement (Kappa = 0.52; 95% CI: 0.36–0.66) was found between LST and IFN-γ production. Moreover while enhancement of CXCL10 in cultures stimulated with SLA was observed in HC with DTH+ and IFN-γ+ and in patients with IFN-γ⁺ and DTH⁻, no enhancement of this chemokine was observed in supernatants of cells of HC with DTH⁺ and IFN-γ⁻.

Conclusions/Significance

This study shows that in addition of LST, the evaluation of antigen specific IFN-γ production should be performed to determine evidence of exposure to leishmania infection. Moreover it suggests that in some HC production of IFN-γ and CXCL10 are performed by cells not involved with DTH reaction.     

<Emphasis Type="Italic">Zostera marina</Emphasis> meadows from the Gulf of California: conservation status

Eelgrass (Zostera marina) population estimates show a decreasing trend worldwide in the second half of the twentieth century. Mexico lacks long-term time series to determine trends for major eelgrass populations and has made no conservation efforts. Therefore, we present the first report on the historic presence of this annual coastal ecosystem in two wetlands of the Gulf of California (GC), the Infiernillo Channel (CIF, largest Z. marina population inside GC) and Concepcion Bay (BCP, the only eelgrass population along GC’s west coast), combining field surveys (1999–2010), aerial photography (2000–2010), satellite imagery (1972–2005), and published reports (1994–2007). Three parameters were used as indicators of conservation status: shoot density, seed banks, and aerial coverage. Average shoot density in the CIF (741 shoots m^?2) was 3.8 times higher than in BCP (194 shoots m^?2), and average seed bank density was similar in both wetlands (17,442 seeds m^?2 vs. 17,000 seeds m^?2). Opportunistic seagrass Ruppia maritima was observed in both wetlands, with higher abundance in summer when Z. marina disappears due to high water temperatures. Eelgrass coverage was three orders of magnitude greater in the CIF (9725 ha) than in BCP (3 ha). The striking difference between these wetlands is the lack of environmental protection for BCP and the protection of the CIF by the Seri indigenous community, which increases human pressure in the former, putting it at high risk of disappearing. Conservation of eelgrass meadows is not only necessary to preserve their ecosystem services but to insure the survival of migratory populations (Pacific brant goose, Branta bernicla), endangered species (Black turtle, Chelonia mydas), and fisheries-related species.     

Cryopreserved CD90+ cells obtained from mobilized peripheral blood in sheep: a new source of mesenchymal stem cells for preclinical applications

Mobilized peripheral blood (MPB) bone marrow cells possess the potential to differentiate into a variety of mesenchymal tissue types and offer a source of easy access for obtaining stem cells for the development of experimental models with applications in tissue engineering. In the present work, we aimed to isolate by magnetic activated cell sorting CD90+ cells from MPB by means of the administration of Granulocyte-Colony Stimulating Factor and to evaluate cell proliferation capacity, after thawing of the in vitro culture of this population of mesenchymal stem cells (MSCs) in sheep. We obtained a median of 8.2 ± 0.6 million of CD90+ cells from the 20-mL MPB sample. After thawing, at day 15 under in vitro culture, the mean CD90+ cells determined by flow cytometry was 92.92 ± 1.29 % and cell duplication time determined by crystal violet staining was 47.59 h. This study describes for the first time the isolation, characterization, and post-in vitro culture thawing of CD90+ MSCs from mobilized peripheral blood in sheep. This population can be considered as a source of MSCs for experimental models in tissue engineering research.     

Seed reproductive biology of the rare aquatic carnivorous plant Aldrovanda vesiculosa (Droseraceae)

Despite the unprecedented global decline in extant populations of Aldrovanda vesiculosa in the last century, little is known about the reproductive biology of this iconic aquatic carnivorous plant. This study aimed to investigate the role of seed‐based reproduction in the ecology of A. vesiculosa, with particular focus on the interplay between the regulation of seed dormancy by temperature cues and the efficacy of exogenous ethylene gas to act as a germination stimulant, the desiccation capacity and long‐term storage potential of seeds for conservation purposes. Sexual reproduction appears to be extremely limited in both natural and naturalized populations across three continents, with high variability in the success of flowering and seed set between sites and between seasons. Overall, flowering yielded few fertile fruit (6–19% of flowers producing fertile fruit) and seed viability was variable but generally low (29–88%). Fecundity appears to be influenced by seasonal climatic conditions and microhabitat characteristics. Aldrovanda vesiculosa possesses physiologically dormant seeds, with germination stimulated by exposure to ethylene gas (>90% germination) at 25 °C. Seeds appear sensitive to desiccation and sub‐zero temperature storage, with no germination and markedly reduced embryo growth after storage of seeds for >1 month at 15 °C and 15% relative humidity or after short‐term (24 h) storage at ?18 °C. In the absence of significant conservation and restoration initiatives, the continuing decline of dystrophic freshwater wetland habitats globally leaves A. vesiculosa facing extinction. As the successful long‐term storage of seeds appears unfeasible based on the approaches described in this study, other alternatives for germplasm conservation such as cryostorage of vegetative tissues or zygotic embryos must be considered for establishing long‐term ex situ collections of critical germplasm.     

Individualized Homeopathic Treatment and Fluoxetine for Moderate to Severe Depression in Peri- and Postmenopausal Women (HOMDEP-MENOP Study): A Randomized,Double-Dummy,Double-Blind,Placebo-Controlled Trial

Background

Perimenopausal period refers to the interval when women''s menstrual cycles become irregular and is characterized by an increased risk of depression. Use of homeopathy to treat depression is widespread but there is a lack of clinical trials about its efficacy in depression in peri- and postmenopausal women. The aim of this study was to assess efficacy and safety of individualized homeopathic treatment versus placebo and fluoxetine versus placebo in peri- and postmenopausal women with moderate to severe depression.

Methods/Design

A randomized, placebo-controlled, double-blind, double-dummy, superiority, three-arm trial with a 6 week follow-up study was conducted. The study was performed in a public research hospital in Mexico City in the outpatient service of homeopathy. One hundred thirty-three peri- and postmenopausal women diagnosed with major depression according to DSM-IV (moderate to severe intensity) were included. The outcomes were: change in the mean total score among groups on the 17-item Hamilton Rating Scale for Depression, Beck Depression Inventory and Greene Scale, after 6 weeks of treatment, response and remission rates, and safety. Efficacy data were analyzed in the intention-to-treat population (ANOVA with Bonferroni post-hoc test).

Results

After a 6-week treatment, homeopathic group was more effective than placebo by 5 points in Hamilton Scale. Response rate was 54.5% and remission rate, 15.9%. There was a significant difference among groups in response rate definition only, but not in remission rate. Fluoxetine-placebo difference was 3.2 points. No differences were observed among groups in the Beck Depression Inventory. Homeopathic group was superior to placebo in Greene Climacteric Scale (8.6 points). Fluoxetine was not different from placebo in Greene Climacteric Scale.

Conclusion

Homeopathy and fluoxetine are effective and safe antidepressants for climacteric women. Homeopathy and fluoxetine were significantly different from placebo in response definition only. Homeopathy, but not fluoxetine, improves menopausal symptoms scored by Greene Climacteric Scale.

Trial Registration

ClinicalTrials.gov NCT01635218

Protocol Publication

http://www.trialsjournal.com/content/14/1/105.     

Infectious Bursal Disease Virus VP5 Polypeptide: A Phosphoinositide-Binding Protein Required for Efficient Cell-to-Cell Virus Dissemination

Infectious bursal disease virus (IBDV), a member of the Birnaviridae family, is a major avian pathogen responsible for an immunosuppressive disease affecting juvenile chickens. The IBDV genome is formed by two dsRNA segments. The largest one harbors two partially overlapping open reading frames encoding a non-structural polypeptide, known as VP5, and a large polyprotein, respectively. VP5 is non-essential for virus replication. However, it plays a major role in IBDV pathogenesis. VP5 accumulates at the plasma membrane (PM) of IBDV-infected cells. We have analyzed the mechanism underlying the VP5 PM targeting. Updated topological prediction algorithm servers fail to identify a transmembrane domain within the VP5 sequence. However, the VP5 polycationic C-terminal region, harboring three closely spaced patches formed by two or three consecutive basic amino acid residues (lysine or arginine), might account for its PM tropism. We have found that mutations, either C-terminal VP5 deletions or replacement of basic amino acids by alanine residues, that reduce the electropositive charge of the VP5 C-terminus abolish PM targeting. Lipid overlay assays performed with an affinity-purified Flag-tagged VP5 (FVP5) protein version show that this polypeptide binds several phosphoinositides (PIP), exhibiting a clear preference for monophosphate species. Experiments performed with FVP5 mutant proteins lacking the polycationic domain demonstrate that this region is essential for PIP binding. Data gathered with IBDV mutants expressing C-terminal deleted VP5 polypeptides generated by reverse genetics demonstrate that the VP5-PIP binding domain is required both for its PM targeting in infected cells, and for efficient virus dissemination. Data presented here lead us to hypothesize that IBDV might use a non-lytic VP5-dependent cell-to-cell spreading mechanism.