Synthesis of Silver nanoparticles (AgNPs) with Antibacterial Activity

The synthesis of nanomaterials is currently one of the most active in nanoscience branches; especially those help improve the human quality life. Silver nanoparticles (AgNPs) are an example of this as it is known to have inhibitory and bactericidal effects. In this work, we report the synthesis of silver nanoparticles by chemical reduction method of silver nitrate (AgNO3) from aqueous solution, using a mix of polivinyl pyrrolidone (PVP) - Aloe Vera as reducing agent and for stabilization and control of particle size. Silver nanoparticles obtained were characterized by Scanning Electron Microscopy (SEM), UV-visible spectroscopy and measurements using Zetasizer Nano ZS were applied to size estimation. The existence of surface plasmon resonance peak at λmax ∼ 420 nm is evidence of silver nanoparticles formation. It was possible to standardize an appropriate protocol for the evaluation of bactericidal activity of the nanoparticles, for mesophilic microorganisms. Bactericidal activity above 90% against these kinds of bacteria was demonstrated. © Published under licence by IOP Publishing Ltd

Evaluation of probiotic lactobacillus as adjuvants for nasal immunization with chimeric pneumococcal vaccine

Vaccine protection against photogenic gram-positive bacteria including different species ofstreptococci is an important problem of contemporary molecular biology. Streptococcal infections are mostcommon bacterial infections surpassing by the economic losses all the infections excluding influenza. The gatesof streptococcal infection, oral cavity or vagina, are covered with immune and non-immune mucosal cells thatare the first line of defenses. Subcutaneous immunization not always stimulate the local immunity on mucosalsurfaces. On the other hand, mucosal vaccination can provide an appropriate local immune response togetherwith systemic protection. However, mucosal immunization often requires usage of special and effectiveadjuvants especially in case of vaccines based on recombinant proteins.For protection against Streptococcus pneumoniae infection, two chimeric recombinant proteins (PSPF andPSP) have been tested as vaccines. Recombinant proteins PSPF and PSP carry immunogenic epitopes fromthe respiratory pathogen including PspA, Spr1875 and PsaA. PSPF structure also carries a fraction of flagellin-FliC molecule in comparison with PSP, which does not have this fragment. This portion of PSPF was includedas internal adjuvant intended for the stimulation of Toll-like receptor 5.In this work, the adjuvant capacity of two probiotic strains, Lactobacillus rhamnosus CRL1505 andL. rhamnosus L32 was evaluated. It was demonstrated that both lactic acid bacteria strains were able to provideadjuvant effects by enhancing the mucosal and systemic immune responses after their co-administration withthe recombinant chimeric protein PSPF. The adjuvant effect of both Lactobacillus strains was significantlydecreased after their thermal inactivation. However, the cell walls of bacteria showed a marked adjuvant activity.An improved protection against several S. pneumoniae serotypes after mucosal immunization of infant micewith PSPF vaccine with probiotic strains or their cell walls was also demonstrated here.The recombinant chimeric protein PSPF administered with immunomodulatory probiotic strains or theirbacterial components would be a promising vaccine for immunization of humans against S. pneumoniae,particularly in children.Одной из наиболее актуальных задач медико-биологической науки является создание вакцинных препаратов против патогенных стрептококков – самых распространенных бактериаль-ных возбудителей заболеваний человека, экономический ущерб от которых уступает лишь потерям от гриппозной инфекции. Входными воротами стрептококковой инфекции являются слизистые обо-лочки респираторного и мочеполового тракта. Парентеральный способ введения вакцин не всегда позволяет добиваться одинаково эффектив-ной стимуляции местного иммунитета на слизистых оболочках, а вакцины, вводимые через слизи-стые оболочки, способны эффективно стимулировать иммунную защиту в области введения, а также обеспечить развитие системного иммунного ответа. Введение через слизистые оболочки вакцинных препаратов белковой природы требует исполь-зования специальных эффективных и безопасных адъювантов, поскольку рекомбинантные белки обычно проявляют недостаточную ммуногенность при таком способе введения. В работе в качестве вакцинных адъювантов при мукозальной иммунизации лабораторных животных пневмококковыми химерными рекомбинантными белками PSPF и PSP были апробированы два штамма пробиотиков – Lactobacillus rhamnosus CRL1505 и L32. Рекомбинантные химерные белки PSPF и PSP несут в своей структуре несколько иммуногенных эпитопов PspA, Spr1875, PsaA и предназначены для вакцинации против инфекции Streptococcus pneumoniae. Белки, отличие которых связано с присутствием в струк-туре PSPF участка молекулы флагеллина – FliC, по-разному стимулировали иммунный ответ при совместном введении с двумя штаммами пробиотиков. Установлено, что оба исследованных штам-ма L. rhamnosus были способны оказывать адъювантный эффект при интраназальном введении вак-цинных белков, проявлявшийся в усилении секреторного и гуморального иммунного ответа на со-вместно введенный рекомбинантный химерный белок PSPF. Выраженной стимуляции продукции специфических IgA носовых смывов и IgG сыворотки крови на PSP под влиянием L. rhamnosus L32 не происходило. Адъювантный эффект от вводимых лактобациллярных препаратов существенно сни-жался после температурной инактивации бактерий, однако препарат клеточных стенок L. rhamnosus CRL1505 проявлял выраженную активность. Стимуляция иммунного ответа адъювантами приводила к усилению протективного эффекта вакцины в экспериментах на лабораторных животных, инфици-рованных S. pneumoniae. Установлено, что некоторые штаммы лактобацилл, в частности Lactobacillus rhamnosus CRL1505 и L32, могут быть использованы в качестве адъювантов в составе мукозальных вакцин, однако эта способность зависит от свойств вакцинного препарата и формы введения пробиотиков.Fil: Leontieva, G. F.. Institute of Experimental Medicine; RusiaFil: Kramskaya, T. A.. Institute of Experimental Medicine; RusiaFil: Grabovskaya, K. B.. Institute of Experimental Medicine; Rusia; RusiaFil: Filimonova, V. Yu.. Institute of Experimental Medicine; Rusia; RusiaFil: Laiño, Jonathan Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Villena, Julio Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Alvarez, Gladis Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Danilenko, V. N.. Academy of Sciences. Institute of General Genetics. Head, Division of Fundamental Genetic Studies in Biotechnology; RusiaFil: Suvorov, A. N.. St. Peterburg State University; Rusia. Institute of Experimental Medicine. Head, Division of Molecular Microbiology; Rusi

Identification of Loci Controlling Restriction of Parasite Growth in Experimental Taenia crassiceps Cysticercosis

Human neurocysticercosis (NC) caused by Taenia solium is a parasitic disease of the central nervous system that is endemic in many developing countries. In this study, a genetic approach using the murine intraperitoneal cysticercosis caused by the related cestode Taenia crassiceps was employed to identify host factors that regulate the establishment and proliferation of the parasite. A/J mice are permissive to T. crassiceps infection while C57BL/6J mice (B6) are comparatively restrictive, with a 10-fold difference in numbers of peritoneal cysticerci recovered 30 days after infection. The genetic basis of this inter-strain difference was explored using 34 AcB/BcA recombinant congenic strains derived from A/J and B6 progenitors, that were phenotyped for T. crassiceps replication. In agreement with their genetic background, most AcB strains (A/J-derived) were found to be permissive to infection while most BcA strains (B6-derived) were restrictive with the exception of a few discordant strains, together suggesting a possible simple genetic control. Initial haplotype association mapping using >1200 informative SNPs pointed to linkages on chromosomes 2 (proximal) and 6 as controlling parasite replication in the AcB/BcA panel. Additional linkage analysis by genome scan in informative [AcB55xDBA/2]F1 and F2 mice (derived from the discordant AcB55 strain), confirmed the effect of chromosome 2 on parasite replication, and further delineated a major locus (LOD = 4.76, p<0.01; peak marker D2Mit295, 29.7 Mb) that we designate Tccr1 (T. crassiceps cysticercosis restrictive locus 1). Resistance alleles at Tccr1 are derived from AcB55 and are inherited in a dominant fashion. Scrutiny of the minimal genetic interval reveals overlap of Tccr1 with other host resistance loci mapped to this region, most notably the defective Hc/C5 allele which segregates both in the AcB/BcA set and in the AcB55xDBA/2 cross. These results strongly suggest that the complement component 5 (C5) plays a critical role in early protective inflammatory response to infection with T. crassiceps

Molecular Tools for Monitoring the Ecological Sustainability of a Stone Bio-Consolidation Treatment at the Royal Chapel, Granada

Background: Biomineralization processes have recently been applied in situ to protect and consolidate decayed ornamental stone of the Royal Chapel in Granada (Spain). While this promising method has demonstrated its efficacy regarding strengthening of the stone, little is known about its ecological sustainability.Methodology/Principal Findings: Here, we report molecular monitoring of the stone-autochthonous microbiota before and at 5, 12 and 30 months after the bio-consolidation treatment (medium/long-term monitoring), employing the well-known molecular strategy of DGGE analyses. Before the bio-consolidation treatment, the bacterial diversity showed the exclusive dominance of Actinobacteria (100%), which decreased in the community (44.2%) after 5 months, and Gamma-proteobacteria (30.24%) and Chloroflexi (25.56%) appeared. After 12 months, Gamma-proteobacteria vanished from the community and Cyanobacteria (22.1%) appeared and remained dominant after thirty months, when the microbiota consisted of Actinobacteria (42.2%) and Cyanobacteria (57.8%) only. Fungal diversity showed that the Ascomycota phylum was dominant before treatment (100%), while, after five months, Basidiomycota (6.38%) appeared on the stone, and vanished again after twelve months. Thirty months after the treatment, the fungal population started to stabilize and Ascomycota dominated on the stone (83.33%) once again. Members of green algae (Chlorophyta, Viridiplantae) appeared on the stone at 5, 12 and 30 months after the treatment and accounted for 4.25%, 84.77% and 16.77%, respectively.Conclusions: The results clearly show that, although a temporary shift in the bacterial and fungal diversity was observed during the first five months, most probably promoted by the application of the bio-consolidation treatment, the microbiota tends to regain its initial stability in a few months. Thus, the treatment does not seem to have any negative side effects on the stone-autochthonous microbiota over that time. The molecular strategy employed here is suggested as an efficient monitoring tool to assess the impact on the stone-autochthonous microbiota of the application of biomineralization processes as a restoration/conservation procedure.This work was supported by the European Regional Development Fund (ERDF), Junta de Andalucía (Spain) and the “Fortalecimiento de la I+D+i” program from the University of Granada, co-financed by grant RNM-3493 and Research Group BIO-103 from Junta de Andalucía, as well as by the Spanish Government through “José Castillejo” program from the “Ministerio de Educación, Cultura y Deporte” (I+D+i 2008-2011), and by the Austrian Science Fund (FWF) under Grant “Elise-Richter V194-B20”

Effects of the mu-opioid receptor antagonist GSK1521498 on hedonic and consummatory eating behaviour: a proof of mechanism study in binge-eating obese subjects.

The opioid system is implicated in the hedonic and motivational processing of food, and in binge eating, a behaviour strongly linked to obesity. The aim of this study was to evaluate the effects of 4 weeks of treatment with the mu-opioid receptor antagonist GSK1521498 on eating behaviour in binge-eating obese subjects. Adults with body mass index ⩾30 kg m−2 and binge eating scale scores ⩾19 received 1-week single-blind placebo run-in, and were then randomized to 28 days with either 2 mg day−1 GSK1521498, 5 mg day−1 GSK1521498 or placebo (N=21 per arm) in a double-blind parallel group design. The outcome measures were body weight, fat mass, hedonic and consummatory eating behaviour during inpatient food challenges, safety and pharmacokinetics. The primary analysis was the comparison of change scores in the higher-dose treatment group versus placebo using analysis of covariance at each relevant time point. GSK1521498 (2 mg and 5 mg) was not different from placebo in its effects on weight, fat mass and binge eating scores. However, compared with placebo, GSK1521498 5 mg day−1 caused a significant reduction in hedonic responses to sweetened dairy products and reduced calorific intake, particularly of high-fat foods during ad libitum buffet meals, with some of these effects correlating with systemic exposure of GSK1521498. There were no significant effects of GSK1521498 2 mg day−1 on eating behaviour, indicating dose dependency of pharmacodynamics. GSK1521498 was generally well tolerated and no previously unidentified safety signals were detected. The potential for these findings to translate into clinically significant effects in the context of binge eating and weight regain prevention requires further investigation

Otimismo comparativo e percepções de controle face à saúde na adolescência: existirão diferenças etárias?

O Otimismo Comparativo (OC), a tendência da maioria das pessoas para ver o seu futuro como mais positivo que o futuro dos outros, e a sua relação com a Percepção de Controle estão pouco estudados na adolescência. Os objetivos deste estudo prenderam-se com a análise das diferenças etárias na adolescência: (1) no OC e Percepções Comparativas de Controle (PCC) face a riscos para a saúde e (2) na forma como as Percepções Absolutas e Comparativas de Controle predizem o OC. Noventa e um pré-adolescentes (M = 11,92 anos) e 97 adolescentes (M = 16,86 anos) saudáveis efectuaram julgamentos de risco e controle (Próprio vs. Alvo) para 8 enfermidades. Os participantes mostraram-se comparativamente otimistas, julgando ter maior controle sobre algumas doenças que o alvo. Não existiram diferenças etárias no OC ou nas PCCs. Estas foram o principal preditor do OC, mediando a relação entre este e as Percepções Absolutas de Controle apenas na sub-amostra dos adolescentes.Comparative Optimism (CO) is the tendency for most people to perceive their future as rosier than the future of others. Such optimistic bias and its relationship with Perceived Control have seldom been studied among adolescents. Hence, this study aimed at exploring age differences throughout adolescence in: 1) CO and Comparative Perceived Control (CPC) over health hazards; 2) the way Absolute and Comparative Perceived Control account for CO. Ninety-one pre-adolescents (M = 11.92 years) and 97 adolescents (M = 16.86 years), all considered healthy, were asked for risk and control judgements (Self vs. Target) regarding 8 health hazards. Generally, participants were comparatively optimistic and saw themselves as having more personal control over some hazards than the target. No age differences were found in CO or CPC. The latter was the best predictor of CO for both cohorts. It mediated the relationship between Absolute Perceived Control and CO in the older participants' sample