No Fixed Limit for Storing Simple Visual Features: Realistic Objects Provide an Efficient Scaffold for Holding Features in Mind.

Prominent theories of visual working memory postulate that the capacity to maintain a particular visual feature is fixed. In contrast to these theories, recent studies have demonstrated that meaningful objects are better remembered than simple, nonmeaningful stimuli. Here, we tested whether this is solely because meaningful stimuli can recruit additional features-and thus more storage capacity-or whether simple visual features that are not themselves meaningful can also benefit from being part of a meaningful object. Across five experiments (30 young adults each), we demonstrated that visual working memory capacity for color is greater when colors are part of recognizable real-world objects compared with unrecognizable objects. Our results indicate that meaningful stimuli provide a potent scaffold to help maintain simple visual feature information, possibly because they effectively increase the objects' distinctiveness from each other and reduce interference.

Sequential encoding aids working memory for meaningful objects' identities but not for their colors.

Previous studies have found that real-world objects' identities are better remembered than simple features like colored circles, and this effect is particularly pronounced when these stimuli are encoded one by one in a serial, item-based way. Recent work has also demonstrated that memory for simple features like color is improved if these colors are part of real-world objects, suggesting that meaningful objects can serve as a robust memory scaffold for their associated low-level features. However, it is unclear whether the improved color memory that arises from the colors appearing on real-world objects is affected by encoding format, in particular whether items are encoded sequentially or simultaneously. We test this using randomly colored silhouettes of recognizable versus unrecognizable scrambled objects that offer a uniquely controlled set of stimuli to test color working memory of meaningful versus non-meaningful objects. Participants were presented with four stimuli (silhouettes of objects or scrambled shapes) simultaneously or sequentially. After a short delay, they reported either which colors or which shapes they saw in a two-alternative forced-choice task. We replicated previous findings that meaningful stimuli boost working memory performance for colors (Exp. 1). We found that when participants remembered the colors (Exp. 2) there was no difference in performance across the two encoding formats. However, when participants remembered the shapes and thus identity of the objects (Exp. 3), sequential presentation resulted in better performance than simultaneous presentation. Overall, these results show that different encoding formats can flexibly impact visual working memory depending on what the memory-relevant feature is.

Trichomonas vaginalis induces IL-1ß production in a human prostate epithelial cell line by activating the NLRP3 inflammasome via reactive oxygen species and potassium ion efflux.

BACKGROUND: Trichomonas vaginalis is a sexually transmitted protozoan parasite that causes vaginitis in women, and urethritis and prostatitis in men. IL-1ß is synthesized as immature pro-IL-1ß, which is cleaved by activated caspase-1. Caspase-1 is, in turn, activated by a multi-protein complex known as an inflammasome. In this study, we investigated the inflammatory response of a prostate epithelial cell line (RWPE-1) to T. vaginalis and, specifically, the capacity of T. vaginalis to activate the NLRP3 inflammasome. METHODS: RWPE-1 cells were stimulated by live T. vaginalis, and subsequent expression of pro-IL-1ß, IL-1ß, NLRP3, ASC and caspase-1 was determined by real-time PCR and Western blotting. IL-1ß and caspase-1 production was also measured by ELISA. To evaluate the effects of NLRP3 and caspase-1 on IL-1ß production, the activated RWPE-1 cells were transfected with small interfering RNAs to silence the NLRP3 and caspase-1 genes. Activation of the NLRP3 inflammasome was observed by fluorescence microscopy. Intracellular reactive oxygen species (ROS) were evaluated by spectrofluorometry. RESULTS: When RWPE-1 cells were stimulated with live T. vaginalis, the mRNA and protein expression of IL-1ß, NLRP3, ASC, and caspase-1 increased. Moreover, silencing of NLRP3 and caspase-1 attenuated T. vaginalis-induced IL-1ß secretion. The NADPH oxidase inhibitor DPI and high extracellular potassium ion suppressed the production of IL-1ß, caspase-1, and the expression of NLRP3 and ASC proteins. The specific NF-κB inhibitor, Bay 11-7082, inhibited IL-1ß production, and also inhibited the production of caspase-1, ASC and NLRP3 proteins. CONCLUSIONS: T. vaginalis induces the formation of the NLRP3 inflammasome in human prostate epithelial cells via ROS and potassium ion efflux, and this results in IL-1ß production. This is the first evidence for activation of the NLRP3 inflammasome in the inflammatory response by prostate epithelial cells infected with T. vaginalis. Prostate 76:885-896, 2016. © 2016 Wiley Periodicals, Inc.

Antioxidative Activity of Platinum Nanocolloid and Its Protective Effect Against Chemical-Induced Hepatic Cellular Damage.

Oxidative stress, a major cause of cellular injuries, is closely associated with a variety of chronic diseases such as cancer, liver diseases, degenerative brain disease and aging. In this study, we investigated antioxidant properties of platinum nanocolloid (PNC) against various oxidative stress conditions in vitro/in vivo by treating PNC on liver cell or tissue. Antioxidant activities of the PNC were determined by measuring quenching capacity on reactive oxygen species and its protective action against hydrogen peroxide or CCl4-induced oxidative cellular damage in HepG2 cell or liver tissue of mice. In vitro study, PNC markedly suppressed the production H2O2, ·OH, α,α-diphenyl-ß-picrylhydrazyl radical and nitric oxide in a dose-dependent manner. PNC also inhibited hydrogen peroxide-induced oxidative cellular damage in HepG2 hepatocytes. In vivo study with mice, PNC reduced hepatic lipid peroxidation and CCl4 induced toxicity. Our results support that platinum nanocolloid has antioxidant activities and protects hepatic cellular oxidative damage. Thus platinum nanocolloid may have a potential to be used as an antioxidant supplement.

Inflammatory response of prostate epithelial cells to stimulation by Trichomonas vaginalis.

BACKGROUND: Trichomonas vaginalis is known as the most common cause of sexually transmitted infection. However, its prevalence may have been underestimated. Trichomonads are detected in prostatic tissue in benign prostatic hyperplasia, prostatitis, and prostate cancer. Our objective was to investigate whether T. vaginalis could induce an inflammatory response in prostate epithelium. METHODS: The cytokine production by human prostate epithelial cell (RWPE-1) activated with T. vaginalis was determined by ELISA and real-time PCR. Intracellular ROS was evaluated by flow cytometry or spectrofluorometry. The protein levels of MAP kinase, NF-κB were analyzed by Western blot. The migration of neutrophil and monocyte were performed in 24-well microplates with filter insert. RESULTS: Incubation of cells of a human prostate epithelial cell line with a live T. vaginalis T016 isolate increased expression of the inflammatory mediators IL-1ß, CCL2, and CXCL8. In addition, ROS, MAPK, and NF-κB activities increased, while inhibitors of ROS, ERK, and NF-κB reduced IL-1ß production. Medium conditioned by incubation of RWPE-1 cells with T. vaginalis contained IL-1ß and stimulated the migration of human neutrophils and monocytes (THP-1 cell line). CONCLUSIONS: We conclude that T. vaginalis may increase IL-1ß expression in human prostate epithelium through activation of ROS, ERK, and NF-κB, and this in turn may induce the migration of neutrophils and monocytes and lead to an inflammatory response. This research is the first attempt to confirm inflammatory reaction caused by T. vaginalis in prostate epithelial cell.

Conceptual information of meaningful objects is stored incidentally.

Prior research has shown that visual working memory capacity is enhanced for meaningful stimuli (i.e., real-world objects) compared to abstract shapes (i.e., colored circles). Here, we hypothesized that the shape of meaningful objects would be better remembered incidentally than the shape of nonmeaningful objects in a color memory task where the shape of the objects is task-irrelevant. We used a surprise-trial paradigm in which participants performed a color memory task for several trials before being probed with a surprise trial that asked them about the shape of the last object they saw. Across three experiments, we found a memory advantage for recognizable shapes relative to scrambled versions of these shapes (Experiment 1) that was robust across different encoding times (Experiment 2), and the addition of a verbal suppression task (Experiment 3). Interestingly, this advantage disappeared when all objects were from the same category (Experiment 4), suggesting that people are incidentally encoding broad conceptual information about object identities, but not visual details. Finally, when we asked about the location of objects in a surprise trial, we did not observe any difference between the two stimulus types (Experiment 5). Overall, these results show that conceptual information about the categories of meaningful objects is incidentally encoded into working memory even when task-irrelevant. This privilege for meaningful information does not exhibit a trade-off with location memory, suggesting that meaningful features influence representations of visual working memory in higher-level visual regions without altering the use of spatial reference frames at the lower level. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Unveiling the time course of visual stabilization through human electrophysiology.

Object positions are coded relative to their surroundings, presumably providing visual stability during eye movements. But when does this perceived stability arise? Here we used a visual illusion, the frame-induced position shift, and measured electrophysiological activity elicited by an object whose perceived position was either shifted because of a surrounding frame or not, thus dissociating perceived and physical locations. We found that visually evoked responses were sensitive to only physical location earlier in time (∼70 ms), but both physical and illusory location information was present at a later time point (∼140 ms). Furthermore, location information could be reliably decoded across physical and illusory locations during the later time interval but not during the earlier time interval, demonstrating that neural activity patterns are shared between the two processes at a later stage. These results suggest that visual stability of objects emerges relatively late and is thus dependent on recurrent feedback from higher processing stages.

The role of motion in visual working memory for dynamic stimuli: More lagged but more precise representations of moving objects.

While most visual working memory studies use static stimuli with unchanging features, objects in the real world are often dynamic, introducing significant differences in the surface feature information hitting the retina from the same object over time (e.g., changes in orientation, lighting, shadows). Previous research on dynamic stimuli has shown that change detection is improved if objects obey rules of physical motion, but it is unclear how memory for visual features interacts with object motion. In the current study, we investigated whether object motion facilitates greater temporal integration of continuously changing surface feature information. In a series of experiments, participants were asked to report the final color of continuously changing colored dots that were either moving or stationary on the screen. We found that the reported colors "lagged behind" the physical states of the dots when they were in motion. We also observed that the precision of memory responses was significantly higher for stimuli in the moving condition compared to the stationary condition. Together, these findings suggest that memory representation is improved - but lagged - for moving objects, consistent with the idea that object motion may facilitate integration of object information over longer intervals.

Two different forms of human CTLA-4 proteins following peripheral T cell activation.

To study expression of human CTLA-4 in peripheral T cells, we developed a new anti-peptide (anti-CTLA4pB) antibody. Both denatured and native forms of CTLA-4 can be recognized by anti-CTLA4pB antibody. After peripheral T cell activation, we observed that most of CTLA-4 is localized primarily to intracellular compartment rather than to the cell surface. Biochemical study using anti-CTLA4pB antibody was revealed two forms of CTLA-4 on activated peripheral T cells. The majority of CTLA-4 was detected as a 34 kDa moiety in cytosolic fraction under reducing conditions. The presence of a 30 kDa CTLA-4 moiety was observed simultaneously in membrane fraction under reducing condition. The post-induction ratio of cytosolic:membrane-bound forms of CTLA-4 was approximately 50:1. Further analysis was indicated that the 34 kDa moiety in cytosolic fraction is part of a 250 kDa multi-protein complex. Antibodies raised against this complex recognized 54 and 75 kDa proteins together with a 34 kDa form of CTLA-4. In contrast, membrane-bound forms of CTLA-4 were 60 and 120 kDa under non-reducing condition. The molar ratio of 60 and 120 kDa oligomers was approximately 1:1. These results may provide evidence for post-translational modification of human CTLA-4 after T cell activation.

Simultaneous expression of allogenic class II MHC and B7.1 (CD80) molecules in A20 B-lymphoma cell line enhances tumor immunogenicity.

We expressed the allogenic class II MHC antigen and B7.1 (CD80) co-stimulatory molecule in A20 beta-lymphoma cells in order to test their efficacy as immuno-stimulating adjuvant agents in inducing tumor-specific immunity. The transduction of the allogenic I-Ab alpha and beta chain genes into A20 cell resulted in a surface expression of the allogenic class II MHC molecules. The expression of the allogenic class II MHC antigen (I-Ab) in A20 cells enhanced the proliferation of T cells in a mixed lymphocyte tumor culture and in vitro cytotoxic T lymphocyte (CTL) generation against parental cells. The B7.1 gene, which is known to be a potent co-stimulatory molecule, was also transduced and expressed in A20 cells, either alone or in combination with I-Ab. The B7.1 transduction alone leads to a similar in vitro immune enhancing effect as I-Ab. When both the I-Ab and B7.1 genes were transduced, the in vitro immunostimulating capacity was further enhanced. Finally, we also tested the A20 cells that were transduced with I-Ab and/or B7.1 for their efficacy as preventive tumor vaccines in vivo. The results indicate that the A20 cells that express both the I-Ab and B7.1 have more potent vaccinating potential, compared to the cells that express only one of the molecules.

Two cases of methemoglobinemia induced by the exposure to nitrobenzene and aniline.

OBJECTIVE: To report two cases of methemoglobinemia induced by inhaled nitrobenzene and dermally absorbed aniline. METHODS: We have evaluated a 37-year-old male worker exposed to nitrobenzene by inhalation while conducting maintenance job of mononitrobenzene pump and a 25-year-old male worker exposed dermally to aniline while unloading. RESULTS: The first case is a 37-year-old male exposed to nitrobenzene. His blood methemoglobin concentration level was initially 19.8%, and chest X-ray was normal. After oxygen therapy, the blood methemoglobin concentration level decreased to 2.1%, and the symptoms were alleviated. The second case is a 25-year-old male exposed dermally to aniline. His chest X-ray was normal, but blood methemoglobin concentration level reached maximally 46.8%. He was treated with methylene blue due to relatively high blood methemoglobin level. Gradually after the treatment, his methemoglobin concentration level was normalized to 0.8% and simultaneously symptoms were resolved. CONCLUSIONS: After the thorough exposure investigations and medical evaluations, we have concluded that these cases were methemoglobinemia induced by occupational exposure to nitrobenzene and aniline. We suggest that businesses which handle methemoglobinemia-causing substances control the engineering process strictly, implement periodic screening, and establish emergency patient management system.

Construction, and in vitro and in vivo analyses of tetravalent immunoadhesins.

Previous observations demonstrated that various immunosuppressive agents and their combination therapies can increase allograft survival rates. However, these treatments may have serious side effects and cannot substantially improve or prolong graft survival in acute graft-versus-host disease (GVHD). To improve the therapeutic potency of divalent immunoadhesins, we have constructed and produced several tetravalent forms of immunoadhesins comprising each of cytotoxic T-lymphocyte-associated antigen-4 (CTLA4), CD2, and lymphocyte activation gene-3 (LAG3). Flow cytometric and T cell proliferation analyses displayed that tetravalent immunoadhesins have a higher binding affinity and more potent efficacy than divalent immunoadhesins. Although all tetravalent immunoadhesins possess better efficacies, tetravalent forms of CTLA4-Ig and LAG3-Ig revealed higher inhibitory effects on T cell proliferation than tetravalent forms of TNFR2-Ig and CD2-Ig. In vitro mixed lymphocytes reaction (MLR) showed that combined treatment with tetravalent CTLA4-Ig and tetravalent LAG3-Ig was highly effective for inhibiting T cell proliferation in both human and murine allogeneic stimulation. In addition, both single tetravalent-form and combination treatments can prevent the lethality of murine acute GVHD. The results of this study demonstrated that co-blockade of the major histocompatibility complex class (MHC)II:T cell receptor (TCR) and CD28:B7 pathways by using tetravalent human LAG3-Ig and CTLA4-Ig synergistically prevented murine acute GVHD.

The effect of disodium cromoglycate, budesonide, and cyclosporin A on interleukin-4, interleukin-5, and interleukin-13 secretions in Der p I-stimulated T cells from house dust mite-sensitive atopic and nonatopic individuals.

Disodium cromoglycate (DSCG), budesonide, and cyclosporin A (CsA) were the well-known immunomodulators for the allergic and immunologic diseases clinically. In this study, we evaluated the characteristics of inhibition on cytokine synthesis of Der p I-stimulated T cells by the same inhibiting concentrations of DSCG, budesonide, and CsA in house-dust mite antigen (Der p I)-specific atopic and nonatopic healthy individuals. Seven house dust mite allergen specific patients were recruited for this study. Seven healthy volunteers were included on the basis of negative allergic manifestations and low serum immunoglobulin E values. Peripheral blood mononuclear cells (PBMCs) were cultured in the presence of recombinant interleukin (rIL)-2 with or without budesonide, DSCG, CsA, and Der p I for 48 hours. Cells were stained with anti-CD4 fluorescein isothiocyanate-conjugated monoclonal antibody, and then anti-human IL-4 phycoerythrin, IL-5, or IL-13 monoclonal antibody, respectively, was added to both blocked and stained samples. Incubation of PBMC from atopics with each immunomodulator and Der p I resulted in the reduction of IL-4 secretion compared with Der p I alone stimulation. However, IL-4 secretion in PBMC from nonatopics was not reduced with DSCG and Der p I stimulation. IL-4, IL-5, and IL-13 secretions of PBMC from atopics were significantly decreased after incubation with each immunomodulator and Der p I, compared with after incubation with Der p I alone. These results might be considered to show either that DSCG has a selective inhibiting effect on cytokine production in T cells from atopics or is a weak inhibitor of cytokine secretions compared with budesonide and CsA at even strength for the inhibition of lymphocyte proliferation in normal, healthy individuals.

The effect of soluble LAG-3 (CD223) treatment in fetal thymic organ culture.

Lymphocyte activation gene-3 (LAG-3; CD223) is structurally similar to CD4 and binds to MHC class II with a 100-fold higher affinity than that of CD4. Soluble LAG-3 (sLAG-3Ig) might be useful for immunotherapy by inducing MHC class II-mediated cell activation. A new form of sLAG-3Ig was constructed containing a critical binding site (D1 and D2 region) to MHC class II, combined with a Fc portion of an immunoglobulin gamma1. After treatment of sLAG-3Ig in fetal thymic organ culture from DO11.10 transgenic mouse, CD4(+) T cell precursors were increased in the positive selection but not affected in the negative selection. Further analysis by treating sLAG-3Ig on thymic epithelial cells revealed that CD40 and MHC class II were up-regulated. These results may demonstrate that the treatment of sLAG-3Ig increases the precursor frequency of CD4(+) T cells by activation of thymic epithelial cells.