In vitro antimicrobial activity of Romanian medicinal plants hydroalcoholic extracts on planktonic and adhered cells

The aim of this study was to assess the antibacterial and antifungal potential of some Romanian medicinal plants, arnica--Arnica montana, wormwood--Artemisia absinthium and nettle--Urtica dioica. In order to perform this antimicrobial screening, we obtained the vegetal extracts and we tested them on a series of Gram-positive and Gram-negative bacteria, and also against two fungal strains. The vegetal extracts showed antimicrobial activity preferentially directed against the planktonic fungal and bacterial growth, while the effect against biofilm formation and development was demonstrated only against S. aureus and C. albicans. Our in vitro assays indicate that the studied plant extracts are a significant source of natural alternatives to antimicrobial therapy, thus avoiding antibiotic therapy, the use of which has become excessive in recent years.     

Hepatitis B, C and D coinfection in HIV-infected patients: prevalence and progress

The HAART therapy has improved life expectancy enabling long latency conditions caused by the hepatitis viruses that became the leading cause of death in HIV infected patients. In this study a group of 300 patients aged from 18 to 63 years were selected in order to assess the prevalence and consequences of HIV and the hepatitis B (HBV), C (HCV) and D (HDV) viruses coinfections. Study groups were designed for each coinfection. These groups were in turn divided in case groups formed of coinfected participants and control groups consisting of mono-infected participants. This classification was obtained by testing the participants for the presence of specific infection markers using the ELISA technique. As a result, in regard to the HIV/HBV coinfection the study group consisted of 16 coinfected participants and 114 HBV-infected participants resulting in a prevalence of the coinfection of 14%. In the case of the HIV/HDV coinfection the study group consisted of 5 coinfected participants and 45 HDV-infected participants. The prevalence of the HIV/HCV coinfection was 25% out of the 170 HCV-infected participants. The effect of the coinfections on the expression and levels of the infection markers was analyzed in constrast to those encountered in the case of the mono-infection. The observed changes in the expression of the specific hepatitis markers indicate the impact of the coinfection with HIV on the progression of the hepatitis infections. In addition, the inadequate immune response towards the hepatitis viruses in the case of the coinfected participants leads to the development of cirrhosis and end stage liver disease.     

Bacterial extract cantastim activates macrophages via TLR-2

CANTASTIM is a second generation bacterial immunomodulator. The aim of this study was to examine the mechanism by which bacterial immunomodulator CANTASTIM induces production of inflammatory cytokines in monocytes/macrophages. Proinflammatory cytokines were induced in PMA-differentiated THP-1 cells by stimulation with TLR agonists and CANTASTIM in the presence or absence of anti-TLR blocking antibodies or isotype matched control antibodies. Also, RNA interference was used to knockdown TLR2 or TLR4 expression in PMA-differentiated THP-1 cells before stimulation. As expected, induction of TNF-alpha and IL-6 by TLR4 agonist LPS was inhibited in a significant manner by anti-TLR4 but not by anti-TLR2 antibody. Unexpectedly, treatment with anti-LR2 blocking antibody inhibited only IL-6 production induced by Pam3CSK4 while the level of TNF-alpha was unchanged. When cells were stimulated by TLR2 agonist heat-killed Listeria monocytogenes the release of TNF-alpha was significantly attenuated by anti-TLR2 antibodies. Silencing of TLR2 led to a statistically significant inhibition of TNF-alpha secretion induced by TLR2 agonist while siRNA silencing of TLR4 did not affect the response to TLR2 agonist. Cells exposed to CANTASTIM produced significant levels of pro-inflammatory cytokines but the levels were lower than LPS-stimulated cells. Production of both cytokines was inhibited by treatment with anti-TLR2 blocking antibody and not by anti-TLR4 antibody. Silencing of TLR2 led to a statistically significant inhibition of TNF-a secretion induced by CANTASTIM while silencing of TLR4 had no effect on the response to CANTASTIM. These results support the hypothesis that CANTASTIM may exert its immunomodulatory and adjuvant activities through interaction of its bacterial components with TLR2.     

The ribonucleotide reductase R1 subunits of herpes simplex virus types 1 and 2 protect cells against TNFα- and FasL-induced apoptosis by interacting with caspase-8

We previously reported that HSV-2 R1, the R1 subunit (ICP10; UL39) of herpes simplex virus type-2 ribonucleotide reductase, protects cells against apoptosis induced by the death receptor (DR) ligands tumor necrosis factor-alpha- (TNFα) and Fas ligand (FasL) by interrupting DR-mediated signaling at, or upstream of, caspase-8 activation. Further investigation of the molecular mechanism underlying HSV-2 R1 protection showed that extracellular-regulated kinase 1/2 (ERK1/2), phosphatidylinositol 3-kinase (PI3-K)/Akt, NF-κB and JNK survival pathways do not play a major role in this antiapoptotic function. Interaction studies revealed that HSV-2 R1 interacted constitutively with caspase-8. The HSV-2 R1 deletion mutant R1(1-834)-GFP and Epstein–Barr virus (EBV) R1, which did not protect against apoptosis induced by DR ligands, did not interact with caspase-8, indicating that interaction is required for protection. HSV-2 R1 impaired caspase-8 activation induced by caspase-8 over-expression, suggesting that interaction between the two proteins prevents caspase-8 dimerization/activation. HSV-2 R1 bound to caspase-8 directly through its prodomain but did not interact with either its caspase domain or Fas-associated death domain protein (FADD). Interaction between HSV-2 R1 and caspase-8 disrupted FADD-caspase-8 binding. We further demonstrated that individually expressed HSV-1 R1 (ICP6) shares, with HSV-2 R1, the ability to bind caspase-8 and to protect cells against DR-induced apoptosis. Finally, as the long-lived Fas protein remained stable during the early period of infection, experiments with the HSV-1 UL39 deletion mutant ICP6∆ showed that HSV-1 R1 could be essential for the protection of HSV-1-infected cells against FasL.     

Joint segmentation, calling, and normalization of multiple CGH profiles

The statistical analysis of array comparative genomic hybridization (CGH) data has now shifted to the joint assessment of copy number variations at the cohort level. Considering multiple profiles gives the opportunity to correct for systematic biases observed on single profiles, such as probe GC content or the so-called "wave effect." In this article, we extend the segmentation model developed in the univariate case to the joint analysis of multiple CGH profiles. Our contribution is multiple: we propose an integrated model to perform joint segmentation, normalization, and calling for multiple array CGH profiles. This model shows great flexibility, especially in the modeling of the wave effect that gives a likelihood framework to approaches proposed by others. We propose a new dynamic programming algorithm for break point positioning, as well as a model selection criterion based on a modified bayesian information criterion proposed in the univariate case. The performance of our method is assessed using simulated and real data sets. Our method is implemented in the R package cghseg.     

How to choose a biodiversity indicator – Redundancy and complementarity of biodiversity metrics in a freshwater ecosystem

A range of biodiversity metrics are available to assess the ecological integrity of aquatic ecosystems. However, performance varies considerably among different types of metrics and provides different information regarding ecosystem conditions, thus making difficult the selection of appropriate metrics for biomonitoring. The present study evaluated the robustness of six biodiversity metrics to assess environmental change and determine their utility as relevant indicators of ecosystem biodiversity and functionality. Traditional metrics such as species richness and Shannon diversity were considered along with alternative metrics such as functional diversity, size diversity and taxonomic distinctness. To that end, invertebrate assemblages in a river floodplain were used as a case study to evaluate the performance of metrics using Generalized Additive Models (GAM). GAM explained between eight and 49% of the variability in biodiversity. The regression models exhibited differences in the response of biodiversity indicators to environmental factors, suggesting that intermediate levels of turbidity and low salinity are conditions favouring increased biodiversity in the study area. Based on correlations among metrics and responses to primary environmental factors, it is concluded that Shannon and functional diversity, and rarefied species richness generated similar information regarding ecosystem conditions (i.e., the metrics were redundant); while size diversity and distinctness provided useful additional data characterizing ecosystem quality (i.e., the metrics were complementary). Functional diversity indicated not only number and dominance of species, but also each species functional role in the community, and was therefore the most informative biodiversity metric. Nevertheless, the use of a combination of metrics, for example functional and size diversity, and variation in taxonomic distinctness, provides complementary data that will serve to achieve a more thorough understanding of ecosystem structure and function, and response to primary environmental influences.     

A decade of molecular cell biology: achievements and challenges

Nature Reviews Molecular Cell Biology celebrated its 10-year anniversary during this past year with a series of specially commissioned articles. To complement this, here we have asked researchers from across the field for their insights into how molecular cell biology research has evolved during this past decade, the key concepts that have emerged and the most promising interfaces that have developed. Their comments highlight the broad impact that particular advances have had, some of the basic understanding that we still require, and the collaborative approaches that will be essential for driving the field forward.     

Variations of the candidate SEZ6L2 gene on Chromosome 16p11.2 in patients with autism spectrum disorders and in human populations

Background

Autism spectrum disorders (ASD) are a group of severe childhood neurodevelopmental disorders with still unknown etiology. One of the most frequently reported associations is the presence of recurrent de novo or inherited microdeletions and microduplications on chromosome 16p11.2. The analysis of rare variations of 8 candidate genes among the 27 genes located in this region suggested SEZ6L2 as a compelling candidate.

Methodology/Principal Findings

We further explored the role of SEZ6L2 variations by screening its coding part in a group of 452 individuals, including 170 patients with ASD and 282 individuals from different ethnic backgrounds of the Human Genome Diversity Panel (HGDP), complementing the previously reported screening. We detected 7 previously unidentified non-synonymous variations of SEZ6L2 in ASD patients. We also identified 6 non-synonymous variations present only in HGDP. When we merged our results with the previously published, no enrichment of non-synonymous variation in SEZ6L2 was observed in the ASD group compared with controls.

Conclusions/Significance

Our results provide an extensive ascertainment of the genetic variability of SEZ6L2 in human populations and do not support a major role for SEZ6L2 sequence variations in the susceptibility to ASD.