Sialyl alpha(2-->3) lactose clusters using carbosilane dendrimer core scaffolds as influenza hemagglutinin blockers

An efficient synthesis of a series of carbosilane dendrimers uniformly functionalized with sialyl α(2 → 3) lactose (Neu5Acα(2 → 3)Galβ(1 → 4)Glcβ1→) moieties was accomplished. The results of a preliminary study on biological responses against influenza virus hemagglutinin, using the sialyl lactose clusters showed unique biological activities on the basis of the structure–activity relationship according to the carbosilane scaffolds.     

Disruption of the human pathogenic yeast Candida albicans catalase gene decreases survival in mouse-model infection and elevates susceptibility to higher temperature and to detergents

Catalase-deficient strains of the human pathogenic yeast Candida albicans were constructed using the URA-blaster method. The disruptant was viable and grew normally in an ordinary culture condition, but became extremely sensitive to treatment with hydrogen peroxide. No catalase activity was observed in a catalase (CCT)-gene-disrupted strain, 1F5-4-1, suggesting that there were no other catalase or catalase-like enzymes in this yeast. The disruptant was shown to be sensitive to higher temperature and to low concentrations of SDS, NP-40, or Triton X-100. After a wild-type CCT gene was reintroduced into the disruptant, catalase activity was restored and the strain became moderately sensitive to treatment with hydrogen peroxide. However, neither the temperature sensitivity nor the susceptibility to SDS observed in the disruptant was restored in the CCT-reintroduced strain. A model infection experiment using wild-type and dCCT strains showed that the disruptants disappeared more rapidly than the wild-type strain in mouse liver, lung, and spleen. These results suggest that the catalase plays a significant role in survival in the host immune system and thus leads this organism to establish infection in the host.     

Individual variation in thermal plasticity and its impact on mass-scaling

Physiological processes vary widely across individuals and can influence how individuals respond to environmental change. Repeatability in how metabolic rate changes across temperatures (i.e. metabolic thermal plasticity) can influence mass-scaling exponents in different thermal environments. Moreover, repeatable plastic responses are necessary for reaction norms to respond to selective forces which is important for populations living in fluctuating environments. Nonetheless, only a small number of studies have explicitly quantified repeatability in metabolic plasticity, and fewer have explored how it can impact mass-scaling. We repeatedly measured standard metabolic rate of n = 42 delicate skinks Lampropholis delicata at six temperatures over the course of four months (N_{[observations]} = 4952). Using hierarchical statistical techniques, we accounted for multi-level variation and measurement error in our data in order to obtain more precise estimates of reaction norm repeatability and mass-scaling exponents at different acute temperatures. Our results show that individual differences in metabolic thermal plasticity were somewhat consistent over time (R_slope = 0.25, 95% CI = 2.48 × 10⁻⁸ – 0.67), however estimates were associated with a large degree of error. After accounting for measurement error, which decreased steadily with temperature, we show that among individual variance remained consistent across all temperatures. Congruently, temperature specific repeatability of average metabolic rate was stable across temperatures. Cross-temperature correlations were positive but were not uniform across the reaction norm. After taking into account multiple sources of variation, our estimates for mass-scaling did not change with temperature and were in line with published values for snakes and lizards. This implies that repeatable plastic responses may promote thermal stability of scaling exponents. Our work contributes to understanding how energy expenditure scales with abiotic and biotic factors and the capacity for reaction norms to respond to selection.     

Scanning Strategies Do Not Modulate Face Identification: Eye-Tracking and Near-Infrared Spectroscopy Study

Background

During face identification in humans, facial information is sampled (seeing) and handled (processing) in ways that are influenced by the kind of facial image type, such as a self-image or an image of another face. However, the relationship between seeing and information processing is seldom considered. In this study, we aimed to reveal this relationship using simultaneous eye-tracking measurements and near-infrared spectroscopy (NIRS) in face identification tasks.

Methodology/Principal Findings

22 healthy adult subjects (8 males and 14 females) were shown facial morphing movies in which an initial facial image gradually changed into another facial image (that is, the subject''s own face was changed to a familiar face). The fixation patterns on facial features were recorded, along with changes in oxyhemoglobin (oxyHb) levels in the frontal lobe, while the subjects identified several faces. In the self-face condition (self-face as the initial image), hemodynamic activity around the right inferior frontal gyrus (IFG) was significantly greater than in the familiar-face condition. On the other hand, the scanning strategy was similar in almost all conditions with more fixations on the eyes and nose than on other areas. Fixation time on the eye area did not correlate with changes in oxyHb levels, and none of the scanning strategy indices could estimate the hemodynamic changes.

Conclusions/Significance

We conclude that hemodynamic activity, i.e., the means of processing facial information, is not always modulated by the face-scanning strategy, i.e., the way of seeing, and that the right IFG plays important roles in both self-other facial discrimination and self-evaluation.     

Purification and initial characterization of the proteasome from the higher plant Spinacia oleracea.

The proteasome (multicatalytic protease complex), a high molecular weight protein complex, has been purified from spinach leaves by successive chromatography on DEAE-cellulose, Bio-Gel A-1.5m, DEAE-TOYOPEARL 650C, and DEAE-5PW. The molecular mass was estimated to be 850 kDa by gel filtration. Polyacrylamide gel electrophoresis of the proteasome gave a single protein band under nondenaturing conditions and at least 10 bands in the range of 21-32 kDa in the presence of sodium dodecyl sulfate. By electron microscopy after negative staining with uranyl acetate, the proteasome from spinach appeared as symmetrical ring-shaped particles. The substrate specificity of proteasomes indicates that they contain at least three types of activity, namely, chymotrypsin-like, Staphylococcus aureus V8 protease-like, and trypsin-like activities. The former two activities were enhanced by poly-L-lysine or sodium dodecyl sulfate. Moreover, we examined the immunological reactivities of proteasomes from various eukaryotes. As a result, cross-immunoreactivities of some subunits were observed. These properties of the proteasome are similar to those of proteasomes isolated from various other eukaryotic sources.     

Genistein Up-Regulates Tumor Suppressor MicroRNA-574-3p in Prostate Cancer

Genistein has been shown to inhibit cancers both in vitro and in vivo, by altering the expression of several microRNAs (miRNAs). In this study, we focused on tumor suppressor miRNAs regulated by genistein and investigated their function in prostate cancer (PCa) and target pathways. Using miRNA microarray analysis and real-time RT-PCR we observed that miR-574-3p was significantly up-regulated in PCa cells treated with genistein compared with vehicle control. The expression of miR-574-3p was significantly lower in PCa cell lines and clinical PCa tissues compared with normal prostate cells (RWPE-1) and adjacent normal tissues. Low expression level of miR-574-3p was correlated with advanced tumor stage and higher Gleason score in PCa specimens. Re-expression of miR-574-3p in PCa cells significantly inhibited cell proliferation, migration and invasion in vitro and in vivo. miR-574-3p restoration induced apoptosis through reducing Bcl-xL and activating caspase-9 and caspase-3. Using GeneCodis software analysis, several pathways affected by miR-574-3p were identified, such as ‘Pathways in cancer’, ‘Jak-STAT signaling pathway’, and ‘Wnt signaling pathway’. Luciferase reporter assays demonstrated that miR-574-3p directly binds to the 3′ UTR of several target genes (such as RAC1, EGFR and EP300) that are components of ‘Pathways in cancer’. Quantitative real-time PCR and Western analysis showed that the mRNA and protein expression levels of the three target genes in PCa cells were markedly down-regulated with miR-574-3p. Loss-of-function studies demonstrated that the three target genes significantly affect cell proliferation, migration and invasion in PCa cell lines. Our results show that genistein up-regulates tumor suppressor miR-574-3p expression targeting several cell signaling pathways. These findings enhance understanding of how genistein regulates with miRNA in PCa.     

Mitochondrial K<Subscript>ATP</Subscript> channels-derived reactive oxygen species activate pro-survival pathway in pravastatin-induced cardioprotection

Reactive oxygen species (ROS) are important intracellular signaling molecules and are implicated in cardioprotective pathways including ischemic preconditioning. Statins have been shown to have cardioprotective effects against ischemia/reperfusion injury, however, the precise mechanisms remain to be elucidated. We hypothesized that ROS-mediated signaling cascade may be involved in pravastatin-induced cardioprotection. Cultured rat cardiomyocytes were exposed to H₂O₂ for 30 min to induce cell injury. Pravastatin significantly suppressed H₂O₂-induced cell death evaluated by propidium iodide staining and the MTT assay. Incubation with pravastatin activated catalase, and prevented a ROS burst induced by H₂O₂, which preserved mitochondrial membrane potential. Protective effects were induced very rapidly within 10 min, which was concordant with the up-regulation of phosphorylated ERK1/2. L-NAME, 5HD, N-acetylcysteine (NAC) and staurosporine inhibited ERK1/2 phosphorylation and also reduced pravastatin-induced cardioprotection, suggesting NO, mitochondrial K_ATP (mitoK_ATP) channels, ROS and PKC should be involved in the cardioprotective signaling. We also demonstrated that pravastatin moderately up-regulated ROS generation in a 5HD-inhibitable manner. In isolated perfused rat heart experiments, pravastatin administered 10 min prior to no-flow global ischemia significantly improved left ventricular functional recovery, and also reduced infarct size, which were attenuated by the treatment with NAC, 5HD, L-NAME or staurosporine. Administration of pravastatin from the beginning of reperfusion also conferred cardioprotection. Pravastatin protected the cardiomyocytes against oxidative stress by preventing the ROS burst and preserving mitochondrial function. Moderately up-regulated ROS production by mitoK_ATP channels opening is involved in the pro-survival signaling cascade activated by pravastatin.     

Tight junction regulates epidermal calcium ion gradient and differentiation

It is well known that calcium ions (Ca²⁺) induce keratinocyte differentiation. Ca²⁺ distributes to form a vertical gradient that peaks at the stratum granulosum. It is thought that the stratum corneum (SC) forms the Ca²⁺ gradient since it is considered the only permeability barrier in the skin. However, the epidermal tight junction (TJ) in the granulosum has recently been suggested to restrict molecular movement to assist the SC as a secondary barrier. The objective of this study was to clarify the contribution of the TJ to Ca²⁺ gradient and epidermal differentiation in reconstructed human epidermis. When the epidermal TJ barrier was disrupted by sodium caprate treatment, Ca²⁺ flux increased and the gradient changed in ion-capture cytochemistry images. Alterations of ultrastructures and proliferation/differentiation markers revealed that both hyperproliferation and precocious differentiation occurred regionally in the epidermis. These results suggest that the TJ plays a crucial role in maintaining epidermal homeostasis by controlling the Ca²⁺ gradient.     

The relationship between consumption of antimicrobial agents and the prevalence of primary Helicobacter pylori resistance

Background. Primary and acquired resistance to the antimicrobial agents is a primary reason for the failure of Helicobacter pylori eradication therapies. We assessed the primary antibiotic resistance rates of H. pylori to three different antibiotics and its relationship due to the annual antibiotic consumption in Japan during the period prior to approval of anti‐H. pylori therapy in Japan. Materials and Methods. Antibiotic susceptibility was tested using the agar dilution method for clarithromycin, amoxicillin and metronidazole. Isolates were considered resistant when the MIC value was > 8 mg/l for metronidazole, > 1 mg/l for clarithromycin and < 0.5 mg/l for amoxicillin. Results. Helicobacter pylori isolates were obtained from 593 Japanese patients from 1995 to 2000. Primary resistance of H. pylori to clarithromycin, metronidazole and amoxicillin was found in 11%, 9% and 0.3% strains, respectively. The proportion with clarithromycin resistance significantly increased from 7% in 1997–98 to 15.2% in 1999–2000 (p = .003). During the same period the metronidazole resistance rate also increased from 6.6% in 1997–98 to 12% in 1999–2000 (p = .02). The prevalence of clarithromycin and metronidazole was related to the annual consumption of these antimicrobial agents. Conclusion. Resistance rates for both clarithromycin and metronidazole appear to reflect the annual consumption of these agents. The high rate of clarithromycin resistance in Japan suggests that the effectiveness of clarithromycin‐based therapies may be compromised in the near future.     

Ontogenetic changes of habitat selection and thyroid hormone levels in black rockfish (Sebastes schlegelii) reared in captivity

This study examined the ontogenetic change in vertical distribution associated with algae and the thyroid hormone profiles of black rockfish (Sebastes schlegelii) under rearing conditions. Experimental observations on distribution were carried on black rockfish from the newly born larval stage to juveniles 75 days after birth (DAB). Position was categorized by vertical location [upper layer, mid layer and lower layer (LL)] and by association with artificial algae (floating algae, bottom algae and no association). Position of fish was observed four times a day, at 0400 (dawn), 1200 (noon), 1800 (dusk) and 2400 (midnight) hours. The majority of fish (>80%) reached transforming larval stage [17.8 ± 0.7 mm total length (TL)] at 25 DAB and juvenile stage (24.3 ± 0.6 mm TL) at 35 DAB. Newly born larvae were mainly distributed at surface and middle layers, the shift of vertical distribution to the LL occurred between 10 and 25 DAB, and over 98% of the individuals were distributed near the bottom after 35 DAB. Association behavior with algae was first observed from 20 to 30 DAB depending on the time of day. Percentage of fish associated with bottom algae increased from 25 to 40 DAB and reached 50–70% thereafter. Thyroid hormone (T₄) showed two surges at 30 and 50 DAB. The first surge corresponded to the transforming larval stage and the occurrence of association behavior with algae. The results indicate that pelagic larvae settle to the bottom layer before metamorphosis, and association behavior with algae appears at the transforming larval stage. A high T₄ concentration at 30 DAB indicates a close relationship with these morphological and behavioral developments.