Synthesis and biological evaluation of Esaprazole analogues showing σ1 binding and neuroprotective properties in vitro

Esaprazole, a molecule previously acknowledged to protect against stomach and intestinal ulcers was surprisingly discovered to have neuroprotective activities and σ₁ binding in vitro. A highly diverse set of Esaprazole analogues 2–5 was prepared in order to increase blood–brain barrier penetration. The analogues showed a structure–activity relationship at the σ₁ receptor closely matching already published pharmacophores. Many of the analogues were shown to have neuroprotective properties in two assays using primary cultures of cortical neurons exposed to glutamate and hydrogen peroxide. However, no apparent SAR for these two assays could be developed. Metabolic stability of the analogues were also investigated and the structure of R¹ had a significant bearing on the ADME properties of the compound resulting in two series of compounds. Compounds in which R¹ was a H or acyl group had good metabolic stability in RLM but poor BBB penetration, whereas compounds where R¹ was a cyclo- or bicyclo-alkyl group had poor metabolic stability but good BBB penetration.     

Efficacy of the Inactivation of Bacterial Spores in White Petrolatum and a Hydrophilic Ointment by Gamma Irradiation

To evaluate the possibilities of using gamma irradiation for the sterilization of ointments, the effect of irradiation on spores of Bacillus pumilus and Bacillus sphaericus in dry material and in two different kinds of ointments was studied. The results indicate that for sterilization purposes irradiation was less effective in white petrolatum as compared to irradiation in the dry state. No such protective effect was found in a hydrophilic ointment. Accordingly, the sterilization dose needed for the sterilization of an ointment can be decided upon only after inactivation experiments with suitable test organisms in the actual preparation.     

Synthesis of 2′-Amino-LNA Purine Nucleosides

The first reported synthesis of 2′-amino-LNA purine nucleosides via a transnucleosidation is accomplished enabling the preparation of oligonucleotides incorporating 2′-amino-LNA with all four natural bases.     

Effect of stress pretreatment on survival of probiotic bacteria in gastrointestinal tract simulator

The effect of stress pretreatment on survival of probiotic Lactobacillus acidophilus La-5, Lactobacillus rhamnosus GG, and Lactobacillus fermentum ME-3 cultures was investigated in the single bioreactor gastrointestinal tract simulator (GITS). The cultures were pregrown in pH-auxostat, subjected to temperature, acid, or bile stress treatment, fast frozen in liquid nitrogen (LN₂), and tested for survival in GITS. After LN₂ freezing the colony forming ability of L. rhamnosus GG and L. fermentum ME-3 nonstressed and stressed cells was well retained (average survival of 75.4 ± 18.3% and 88.0 ± 7.2%, respectively). L. acidophilus La-5 strain showed good survival of auxostat nonstressed cells after fast freezing (94.2 ± 15.0), however the survival of stress pretreated cells was considerably lower (30.8 ± 8.5%). All LN₂ frozen auxostat cultures survived well in the acid phase of the GIT simulation (survival 81 ± 21%); however, after the bile phase, the colony formation ability of L. acidophilus La-5, L. rhamnosus GG, and L. fermentum ME-3 decreased by approximately 1.4 ± 0.2, 3.8 ± 0.3, and 3.5 ± 1.2 logarithmic units, respectively. No statistically relevant positive effect of stress pretreatments on survival of LN₂ frozen L. acidophilus La-5, L. rhamnosus GG, and L. fermentum ME-3 in GITS was observed.     

Campylobacter jejuni Motility Is Required for Infection of the Flagellotropic Bacteriophage F341

Previous studies have identified a specific modification of the capsular polysaccharide as receptor for phages that infect Campylobacter jejuni. Using acapsular kpsM mutants of C. jejuni strains NCTC11168 and NCTC12658, we found that bacteriophage F341 infects C. jejuni independently of the capsule. In contrast, phage F341 does not infect C. jejuni NCTC11168 mutants that either lack the flagellar filaments (ΔflaAB) or that have paralyzed, i.e., nonrotating, flagella (ΔmotA and ΔflgP). Complementing flgP confirmed that phage F341 requires rotating flagella for successful infection. Furthermore, adsorption assays demonstrated that phage F341 does not adsorb to these nonmotile C. jejuni NCTC11168 mutants. Taken together, we propose that phage F341 uses the flagellum as a receptor. Phage-host interactions were investigated using fluorescence confocal and transmission electron microscopy. These data demonstrate that F341 binds to the flagellum by perpendicular attachment with visible phage tail fibers interacting directly with the flagellum. Our data are consistent with the movement of the C. jejuni flagellum being required for F341 to travel along the filament to reach the basal body of the bacterium. The initial binding to the flagellum may cause a conformational change of the phage tail that enables DNA injection after binding to a secondary receptor.     

Past and future range shifts and loss of diversity in dwarf willow (Salix herbacea L.) inferred from genetics, fossils and modelling

Aim Climate change may cause loss of genetic diversity. Here we explore how a multidisciplinary approach can be used to infer effects of past climate change on species distribution and genetic diversity and also to predict loss of diversity due to future climate change. We use the arctic‐alpine plant Salix herbacea L. as a model. Location Europe, Greenland and eastern North America. Methods We analysed 399 samples from 41 populations for amplified fragment length polymorphism (AFLP) to identify current patterns of genetic structure and diversity and likely historical dispersal routes. Macrofossil records were compiled to infer past distribution, and species distribution models were used to predict the Last Glacial Maximum (LGM) and future distribution of climatically suitable areas. Results We found strong genetic differentiation between the populations from Europe/East Greenland and those from Canada/West Greenland, indicating a split probably predating the LGM. Much less differentiation was observed among the four genetic groups identified in Europe, and diversity was high in the Scandinavian as well as in southern alpine populations. Continuous distribution in Central Europe during the last glaciation was inferred based on the fossil records and distribution modelling. A 46–57% reduction in suitable areas was predicted in 2080 compared to present. However, mainly southern alpine populations may go extinct, causing a loss of about 5% of the genetic diversity in the species. Main conclusions From a continuous range in Central Europe during the last glaciation, northward colonization probably occurred as a broad front maintaining diversity as the climate warmed. This explains why potential extinction of southern populations by 2080 will cause a comparatively low loss of the genetic diversity in S. herbacea. For other species with different glacial histories, however, the expected climate‐change induced regional extinction may cause a more severe loss of genetic diversity. We conclude that our multidisciplinary approach may be a useful tool for assessing impact of climate change on loss of genetic diversity.     

Facial Displays in Cebus apella

Tufted capuchins are diurnal New World primates whose social interactions involve vocal and visual communication. We aimed to describe their facial displays and assessed the use (in relation to rank and age/sex classes of the sender or the receiver or both) and the social function of the most frequent ones. More specifically, we analyzed the temporal relationship between each facial display and specific classes of behaviors, e.g., play, aggression, performed by the sender and by the receiver (Pre-Post-Event Histogram [PPEH]). We observed 20 captives, belonging to 2 groups, for a total of 320 h. The capuchins displayed relaxed open-mouth, silent bared-teeth, open-mouth threat, lip-smacking, open-mouth silent bared-teeth, scalp lifting, and, rarely, protruded lips. The repertoire and the meanings of the different facial expressions are similar to those described for Catarrhini. In some cases, such as for the silent bared-teeth display, the meaning depends on the age of the sender. Silent bared-teeth is associated with play in juveniles and with submissiveness of the sender to the receiver and affiliative interactions in adults. The finding, and the fact that silent bared-teeth display is used during courtship (Carosi and Visalberghi, 2002), support Preuschoft and van Hooff’s (1995, 1997) power asymmetry hypothesis of motivational emancipation, according to which there is convergence between affiliative and submissive behaviors in species with a high degree of social tolerance.     

Evidence for a pre-latent form of the serpin plasminogen activator inhibitor-1 with a detached beta-strand 1C

Latency transition of plasminogen activator inhibitor-1 (PAI-1) occurs spontaneously in the absence of proteases and results in stabilization of the molecule through insertion of its reactive center loop (RCL) as a strand in beta-sheet A and detachment of beta-strand 1C (s1C) at the C-terminal hinge of the RCL. This is one of the largest structural rearrangements known for a folded protein domain without a concomitant change in covalent structure. Yet, the sequence of conformational changes during latency transition remains largely unknown. We have now mapped the epitope for the monoclonal antibody H4B3 to the cleft revealed upon s1C detachment and shown that H4B3 inactivates recombinant PAI-1 in a time-dependent manner. With fluorescence spectroscopy, we show that insertion of the RCL is accelerated in the presence of H4B3, demonstrating that the loss of activity is the result of latency transition. Considering that the epitope for H4B3 appears to be occluded by s1C in active PAI-1, this finding suggests the existence of a pre-latent conformation on the path from active to latent PAI-1 characterized by at least partial detachment of s1C. Functional characterization of mutated PAI-1 variants suggests that a salt-bridge between Arg273 and Asp224 may stabilize the pre-latent conformation. The binding of H4B3 and of a peptide targeting the cleft revealed upon s1C detachment was hindered by the glycans attached to Asn267. Conclusively, we have provided evidence for the existence of an equilibrium between active PAI-1 and a pre-latent form, characterized by reversible detachment of s1C and formation of a glycan-shielded cleft in the molecule.