The effect of expertise on memory conformity: a test of informational influence.

Conforming to erroneous memory reports of co-witnesses can have serious impacts on subsequent forensic investigation and court reports. One theoretical explanation proposed is that memory conformity arises due to informational influence; the co-witness desires to give accurate information and reports the co-witness's version because they perceive the co-witness as being more credible. We tested the idea that perceptions of credibility drive memory conformity. We manipulated credibility through expertise; specifically, by telling participants that the (confederate) co-witness had previously worked as either a policeman (high expertise) or an electrician (low expertise). After a discussion with the co-witness, we assessed cued-recall memory and perceptions of credibility about the co-witness and the self. We found that higher expertise led to greater memory conformity. Although higher expertise also led to higher credibility assessments of the co-witness, this was only for perceptions of the credibility as an eye-witness and memory confidence, neither of which predicted memory conformity. By contrast, memory accuracy of the co-witness relative to self-memory accuracy predicted memory conformity, but this was not affected by expertise. These results show support for an informational influence explanation but suggest that expertise perceptions operate differently from our explanation.

Effectiveness of telephone counseling in managing psychological outcomes after spinal cord injury: a preliminary study.

OBJECTIVE: To determine whether an individualized counseling intervention delivered by telephone-telecounseling-feasibly improves the emotional adjustment of adults with a newly acquired spinal cord injury (SCI). DESIGN: Randomized controlled trial. SETTING: Spinal injuries unit of a rehabilitation center. PARTICIPANTS: Adults (N=40) aged 18 or older, who were recently discharged home from inpatient spinal rehabilitation, were randomly assigned to a telecounseling treatment or standard-care control group. All participants had recently received psychological treatment as inpatients in order to help assist them in adjusting to their disability. Referral to the inpatient psychology service was therefore a key indicator of participants' baseline distress levels and, consequently, their need for counseling support postdischarge. INTERVENTION: Seven telecounseling sessions were delivered over a 12-week period by a single psychologist (D.D.). Pre- and postintervention data, plus a 3-month follow-up assessment, were compared with that of an SCI control group who received standard care. MAIN OUTCOME MEASURES: Psychosocial outcome was measured using the following: Depression Anxiety Stress Scale-21; Mini International Neuropsychiatric Interview; Spinal Cord Lesion Emotional Wellbeing and Coping Strategies Questionnaires; and the Multidimensional Measure of Social Support. Cost-effectiveness and clinical feasibility were also evaluated. RESULTS: Telecounseling participants reported clinical improvements in depression and anxiety and aspects of SCI coping immediately postintervention. However, these treatment gains were not statistically significant. Additionally, treatment effects were minimal at 3-month follow-up. Delivery related outcomes, including participation rate and cost analyses, were all positive. CONCLUSIONS: The results suggest that continued psychological services for individuals reporting distress during their inpatient rehabilitation is important and that such services can be delivered by telephone cost-effectively and efficiently. However, the long-term benefits of telecounseling, once ceased, were not demonstrated.

Up-regulation of complement factor B in retinal pigment epithelial cells is accompanied by complement activation in the aged retina.

Complement activation is involved in the pathogenesis of age-related macular degeneration. How complement is activated in the retina is not known. Previously we have shown that complement factor H (CFH) is constitutively expressed by retinal pigment epithelial (RPE) cells and the production of CFH is negatively regulated by inflammatory cytokines and oxidative insults. Here we investigated the production and regulation of complement factor B (CFB) in RPE cells. Immunohistochemistry showed that CFB is expressed at low levels on the apical portion of the RPE cells in normal physiological conditions. With age, CFB expression increases and extends to the basal part of RPE cells. Confocal microscopy and real-time PCR of RPE cultures indicated that the production of CFB by RPE cells is positively regulated by TNF-alpha, IFN-gamma and long-term (30 days) photoreceptor outer segments treatments. Increased CFB expression in RPE cells in vivo is accompanied by the accumulation of complement C3 and C3a deposition at the Bruch's membrane and the basal layer of RPE cells. Our results suggest that RPE cells play important roles in regulating complement activation in the retina. Increased complement activation in the aged retina may be important for retinal homeostasis in the context of accumulating photoreceptor waste products.

Characterization of a spontaneous mouse retinal pigment epithelial cell line B6-RPE07.

PURPOSE: A spontaneously arising retinal pigment epithelial (RPE) cell line (B6-RPE07) was cloned from a primary culture of mouse RPE cells and maintained in culture for more than 18 months. Morphologic and functional properties of this cell line have been characterized. METHODS: The morphology of the B6-RPE07 cells was examined by phase-contrast light microscopy, electron microscopy, and confocal microscopy. Barrier properties were measured by the flux of fluorescence from the apical to the basolateral compartment of culture chambers. The abilities of the cells to bind/phagocytose photoreceptor outer segments (POS) were determined by confocal microscopy, electron microscopy, and flow cytometry. Cytokine/chemokine secretion was measured by cytometric bead array. The expression of visual cycle proteins was determined by RT-PCR and Western blotting. RESULTS: In standard culture conditions, B6-RPE07 cells display cobblestone morphology. When cultured on three-dimensional (3D) collagen gel-coated membranes, B6-RPE07 cells exhibit a monolayer epithelial polarization with apical surface microvilli. Immunohistochemistry of B6-RPE07 cultures revealed a high expression of pan-cytokeratin. B6-RPE07 cells also expressed the retinal pigment epithelium-specific marker CRALBP, but not RPE65. Cell junction proteins ZO-1 and beta-catenin, but not claudin-1/3 or occludin-1, were observed in B6-RPE07 cells. B6-RPE07 cells are able to bind, phagocytose, and digest POS. Finally, B6-RPE07 cells produce high levels of IL-6 and CCL2. CONCLUSIONS: This is the first report of a mouse RPE cell line with morphology, phenotype, and function similar to those of in vivo mouse RPE cells. This cell line will be a valuable resource for future RPE studies, in particular for in vivo gene modification and transplantation studies.

FTY720 in corneal concordant xenotransplantation.

BACKGROUND: : Currently, there are no effective treatments for the control of corneal xenograft rejection. We evaluated the efficacy and mode of action of a novel immunosuppressant, FTY720, in a model of corneal xenograft transplantation. METHODS: : Rat-to-mouse corneal xenografts were performed and the effects of treatment with daily intraperitoneal injections of FTY720 (0.5 or 3.0 mg/kg/day) or saline from 2 days pretransplantation were assessed clinically. Immunohistochemical studies of the grafts and flow cytometry of the draining lymph node subpopulations were performed at the time of clinical rejection. RESULTS: : Treatment with FTY720 delayed the onset of corneal rejection, from 8 days postgraft in saline-treated mice to 12.0 +/- 0.89 days for low-dose FTY720 treatment and 15.6 +/- 3.1 days for high-dose FTY720 treatment (both P<0.001). Histologically, FTY-treated animals had a markedly reduced inflammatory response in the anterior chamber and cornea after replacement of the xenograft epithelium with normal healthy host epithelium. In contrast, saline-treated xenografts had persisting corneal epithelial defects and ulceration. In the draining lymph nodes, FTY720 not only inhibited the increase in the cell number observed in saline-treated recipients of xenografts, but also reduced the expression of activation markers on B cells (MHC class II and CD86). CONCLUSIONS: : FTY720 treatment significantly delayed rejection and decreased its severity in a dose-dependent manner in a rat-to-mouse model of corneal xenotransplantation. Since corneal xenograft rejection is mediated not by natural antibodies or CD8+ T cells directly, but by CD4+ T cells, the data from these experiments imply that FTY720 mediated its effect via CD4+ T cells.

Antigen-specific inhibition of experimental autoimmune uveoretinitis by bone marrow-derived immature dendritic cells.

PURPOSE: To investigate the effect of maturation status of bone marrow-derived dendritic cells (BMDCs) on the in vivo immune response to interphotoreceptor retinoid-binding protein (IRBP) 161-180 peptide in experimental autoimmune uveoretinitis (EAU). METHODS: Immature and mature BMDCs were generated without or with the stimulation by lipopolysaccharide (LPS), and their mRNA cytokine profile and phenotype were analyzed by RNase protection assay and flow cytometry. The effect of immature and mature DCs in inducing antigen-specific T-cell proliferation and cytokine profile was further investigated in an IRBP peptide-induced model of EAU. RESULTS: BMDCs generated in granulocyte-macrophage-colony-stimulating factor (GM-CSF) were relatively immature (i)DCs, as determined by flow cytometry and cytokine profile. However, stimulation with LPS induced these cells to become mature (m)DCs with higher levels of surface major histocompatibility complex (MHC)-II and costimulatory molecules and higher mRNA expression of IL-1alpha, -1beta, -6, and -12. Subcutaneous administration of iDCs induced a state of relative tolerance to the peptide induced-EAU, and the effect was lost after the DCs underwent maturation induced by in vitro exposure to LPS. In vitro, both iDCs and mDCs induced typical peptide-specific T-cell proliferation, but IFN-gamma production by uveitogenic T cells was markedly inhibited by iDCs. In vivo, peptide-loaded iDCs induced draining lymph node (DLN) cells to secrete a distinct pattern of cytokine: namely, increased IL-10 and IL-5 and decreased IFN-gamma and IL-2, indicating an altered immune responses to a low T-helper (Th) cell type 1 profile and a high Th2 profile after uveitogenic challenge. CONCLUSIONS: The data suggest that induction of tolerance to an autoantigen by peptide-loaded DCs requires presentation of antigen by iDCs and involves the generation of a high-level IL-10 and IL-5 immune response in DLN cells.

Secretion of interleukin-10 or interleukin-12 by LPS-activated dendritic cells is critically dependent on time of stimulus relative to initiation of purified DC culture.

Dendritic cells (DC) are key regulators of adaptive immunity with the potential to induce T cell activation/immunity or T cell suppression/tolerance. DC are themselves induced by "maturation" signals such as bacterial lipopolysaccharide (LPS). We demonstrate here that LPS can stimulate DC to display similar maturation phenotypes but to differentiate toward an interleukin (IL)-10(high)- or IL-12(high)-secretor profile depending on the timing of maturation signal induction. Immediate/early administration of LPS induced purified bone marrow-derived DC (BMDC) to differentiate as IL-10(high)IL-12(low)-secreting cells, termed early DC (eDC). Conversely, delayed administration of LPS altered the DC cytokine profile to IL-10(low)IL-12(high), termed later DC (lDC). The presence of IL-4 enhanced the yield and maturation of BMDC but inhibited LPS-induced IL-10 production by eDC. In contrast, interferon-gamma reduced the yield of DC but promoted the level of LPS-induced IL-10 production by lDC. Our data provide new evidence that ex vivo manipulation and the cytokine environment regulate DC maturation status and cytokine-secretor phenotype with implications for the control of T cell differentiation and function via DC-based immunotherapeutic strategies.