Measuring kinetic dissociation/association constants between Lactococcus lactis bacteria and mucins using living cell probes

In this work we focused on quantifying adhesion between Lactococcus lactis, the model for lactic acid bacteria (LAB) and mucins. Interactions between two strains of L. lactis (IBB477 and MG1820 as control) and pig gastric mucin–based coating were measured and compared with the use of atomic force microscopy. Analysis of retraction force-distance curves shed light on the differential contributions of nonspecific and specific forces. An increased proportion of specific adhesive events was obtained for IBB477 (20% vs. 5% for the control). Blocking assays with free pig gastric mucin and its O-glycan moiety showed that oligosaccharides play a major (but not exclusive) role in L. lactis-mucins interactions. Specific interactions were analyzed in terms of kinetic constants. An increase in the loading rate of atomic force microscope tip led to a higher force between interacting biological entities, which was directly linked to the kinetic dissociation constant (K_off). Enhancing the contact time between the tip and the sample allowed an increase in the interaction probability, which can be related to the kinetic association constant (K_on). Variations in the loading rate and contact time enabled us to determine K_on (3.3 × 10² M⁻¹·s⁻¹) and K_off (0.46 s⁻¹), and the latter was consistent with values given in the literature for sugar-protein interactions.     

Extrapair paternity in golden-cheeked gibbons (Nomascus gabriellae) in the secondary lowland forest of Cat Tien National Park, Vietnam

We observed 18 groups of golden-cheeked gibbons (Nomascus gabriellae) in the secondary lowland forest in Cat Tien National Park from January 2004 to December 2005 to obtain information about the social organization of this little-studied species, in an area where the population is recovering through increased protection and forest regeneration. DNA from faecal samples of 10 infants and juveniles identified 1 case of extrapair paternity. DNA from faecal samples of 18 adults from three communities revealed the majority of adults sampled of both sexes to be related to adults in neighbouring territories. Overall, the indications are that in this empty habitat, gibbons appear to be able to establish territories adjacent to those of their kin.     

Key role of regulated upon activation normal T-cell expressed and secreted, nonstructural protein1 and myeloperoxidase in cytokine storm induced by influenza virus PR-8 (A/H1N1) infection in A549 bronchial epithelial cells

Influenza virus infection causes severe respiratory disease such as that due to avian influenza (H5N1). Influenza A viruses proliferate in human epithelial cells, which produce inflammatory cytokines/chemokines as a "cytokine storm" attenuated with the viral nonstructural protein 1 (NS1). Cytokine/chemokine production in A549 epithelial cells infected with influenza A/H1N1 virus (PR-8) or nonstructural protein 1 (NS1) plasmid was examined in vitro. Because tumor necrosis factor-α (TNF-α) and regulated upon activation normal T-cell expressed and secreted (RANTES) are predominantly produced from cells infected with PR-8 virus, the effects of mRNA knockdown of these cytokines were investigated. Small interfering (si)TNF-α down-regulated RANTES expression and secretion of RANTES, interleukin (IL)-8, and monocyte chemotactic protein-1 (MCP-1). In addition, siRANTES suppressed interferon (IFN)-γ expression and secretion of RANTES, IL-8, and MCP-1, suggesting that TNF-α stimulates production of RANTES, IL-8, MCP-1, and IFN-γ, and RANTES also increased IL-8, MCP-1, and IFN-γ. Furthermore, administration of TNF-α promoted increased secretion of RANTES, IL-8, and MCP-1. Administration of RANTES enhanced IL-6, IL-8, and MCP-1 production without PR-8 infection. These results strongly suggest that, as an initial step, TNF-α regulates RANTES production, followed by increase of IL-6, IL-8, and MCP-1 and IFNs concentrations. At a later stage, cells transfected with viral NS1 plasmid showed production of a large amount of IL-8 and MCP-1 in the presence of the H(2)O(2)-myeloperoxidse (MPO) system, suggesting that NS1 of PR-8 may induce a "cytokine storm" from epithelial cells in the presence of an H(2)O(2)-MPO system.     

Complete Demonstration of the Valence Electronic Structure Inside a Practical Organic Solar Cell Probed by Low Energy Photoemission

The complete electronic structure inside a practical organic photovoltaic (OPV) device consisting of a trilayer structure of copper‐phthalocyanine (CuPc), fullerene (C₆₀), and bathocuproine (BCP) is demonstrated using low‐energy ultraviolet photoelectron spectroscopy (LE‐UPS) and photoelectron yield spectroscopy (PYS). The molecular orbital energy alignment and electrostatic potential distribution throughout the entire device is illustrated based on the LE‐UPS results. A favorable potential gradient to carry the photogenerated holes and electrons is manifested to be built spontaneously in the CuPc and BCP layers, respectively. Furthermore, the ultrahigh sensitivity measurements of LE‐UPS clearly unveil the distributions of faint density‐of‐states in the energy‐gap region in the organic films. Substantially barrierless contacts to both electrodes are fulfilled by the existence of these gap states. The electronic structure under simulated sunlight illumination is examined for the purpose of elucidating the electronic structures inside the working devices in the open‐circuit condition. These results indicate experimentally the electronic functionalities of each organic material, in particular of the BCP buffer layer, on the cell efficiency.     

Analysis of Pesticides in Soil Using Dispersive Solid Phase Extraction Coupled to GC-MS

A multi-residue method using dispersive solid phase extraction and gas chromatography with mass spectrometric detection has been developed for determination of trace levels of 103 pesticides, including organophosphate, organochlorine, carbamate, and pyrethroid compounds in agricultural soil. Dispersive solid phase extraction using 10 mL of acetonitrile for 3 min of extraction time showed satisfactory extraction efficiency. Recoveries of pesticides from fortified agricultural soil samples ranged from 65% to 117% for three different fortified levels of 50, 100, and 500 μg/kg and relative standard deviations of the recoveries are below 19%. Detection and quantification limits ranged from 1 to 13 μg/kg and from 3 to 38 μg/kg, respectively. The proposed method was less time-consuming, safer, and easy to use for routine analysis.     

Lifecourse Adversity and Physical Performance across Countries among Men and Women Aged 65-74

Background

This study examines the associations between lifecourse adversity and physical performance in old age in different societies of North and South America and Europe.

Methods

We used data from the baseline survey of the International Study of Mobility in Aging, conducted in: Kingston (Canada), Saint-Hyacinthe (Canada), Natal (Brazil), Manizales (Colombia) and Tirana (Albania). The study population was composed of community dwelling people between 65 and 74 years of age, recruiting 200 men and 200 women at each site. Physical Performance was assessed with the Short Physical Performance Battery (SPPB). Economic and social adversity was estimated from childhood adverse events, low education, semi-skilled occupations during adulthood and living alone and insufficient income in old age.

Results

A total of 1995 people were assessed. Low physical performance was associated with childhood social and economic adversity, semi-skilled occupations, living alone and insufficient income. Physical performance was lower in participants living in Colombia, Brazil and Albania than in Canada counterparts, despite adjustment for lifecourse adversity, age and sex.

Conclusions

We show evidence of the early origins of social and economic inequalities in physical performance during old age in distinct populations and for the independent and cumulative disadvantage of low socioeconomic status during adulthood and poverty and living alone in later life.     

Suprafenacine,an Indazole-Hydrazide Agent,Targets Cancer Cells Through Microtubule Destabilization

Microtubules are a highly validated target in cancer therapy. However, the clinical development of tubulin binding agents (TBA) has been hampered by toxicity and chemoresistance issues and has necessitated the search for new TBAs. Here, we report the identification of a novel cell permeable, tubulin-destabilizing molecule - 4,5,6,7-tetrahydro-1H-indazole-3-carboxylic acid [1p-tolyl-meth-(E)-ylidene]-hydrazide (termed as Suprafenacine, SRF). SRF, identified by in silico screening of annotated chemical libraries, was shown to bind microtubules at the colchicine-binding site and inhibit polymerization. This led to G₂/M cell cycle arrest and cell death via a mitochondria-mediated apoptotic pathway. Cell death was preceded by loss of mitochondrial membrane potential, JNK - mediated phosphorylation of Bcl-2 and Bad, and activation of caspase-3. Intriguingly, SRF was found to selectively inhibit cancer cell proliferation and was effective against drug-resistant cancer cells by virtue of its ability to bypass the multidrug resistance transporter P-glycoprotein. Taken together, our results suggest that SRF has potential as a chemotherapeutic agent for cancer treatment and provides an alternate scaffold for the development of improved anti-cancer agents.