Osteopontin (OPN) is a phosphorylated acidic glycoprotein that has been implicated in a number of physiological and pathological events, including maintenance or reconfiguration of tissue integrity during inflammatory processes. As such, it is required for stress-induced bone remodeling and certain types of cell-mediated immunity. It also acts in dystrophic calcification, coronary restenosis, and tumor cell metastasis. An RGD-containing protein, OPN exists both as an immobilized ECM molecule in mineralized tissues and as a cytokine in body fluids; it is not a significant part of typical nonmineralized ECM.OPN can engage a number of receptors, including the integrins α v (β 1 , β 3 , or β 5 ) and (α 4 , α 5 , α 8 , or α 9 )β 1 , and it may also be a ligand for certain variant forms of CD44, specifically v6 and/or v7, but possibly only in conjunction with a β 1 integrin (1). These receptors directly or indirectly activate cellular signaling pathways, allowing OPN to mediate cell-matrix, and possibly cell-cell, interactions. Several studies have demonstrated that OPN delivers a prosurvival, antiapoptotic signal to the cell. Here, we argue that OPN influences cellular functions in a unique manner, by mimicking key aspects of an ECM signal outside the confines of the ECM. We will explore this idea by reviewing recent data concerning OPN signaling and the consequences of OPN deficiency in several settings, notably inflammatory processes involving immune cells and bone cells. Figure 1 illustrates some of the features of the OPN molecule. The presence of a conserved thrombin cleavage site suggests that certain physiological processes employing OPN depend upon its cleavage by thrombin. Some of these adhesive interactions involve the RGD sequence, which is found in various ECM proteins and binds directly to many integrins. Both RGD-dependent and RGD-independent OPN-receptor interactions are modulated by thrombin cleavage of OPN. For instance, thrombin-cleaved OPN, but not intact OPN, can support RGD-dependent migration of melanoma cells (2). Likewise, K562 erythroleukemia cells bind via activated α 5 β 1 to the RGD sequence in thrombin-cleaved OPN. A non-RGD-dependent interaction with α 9 β 1 offers yet another example: only after cleavage by thrombin can human OPN interact with α 9 β 1 via the sequence SVVYGLR, which is located between the RGD sequence and the thrombin cleavage site (3). This binding motif is also responsible for the RGD-independent binding of the J6 T-cell line to activated α 4 β 1 , but in the latter case, cleavage by thrombin is not required for binding of OPN by activated integrin (4). Adhesion of B lymphocytes via α v β 3 also occurs via a cryptic binding site masked in intact OPN, and TPA-activated B lymphocytes attach more effectively to thrombincleaved OPN than to full-length OPN (5). In contrast, Osteopontin as a means to cope with environmental insults: regulation of inflammation, tissue remodeling, and cell survival OPN-integrin interactions: consequences of cleavage by thrombin
Previous quantitative reviews of research on the efficacy of psychotherapy for depression have included only a subset of the available research or limited their focus to a single outcome measure. The present review offers a more comprehensive quantitative integration of this literature. Using studies that compared psychotherapy with either no treatment or another form of treatment, this article assesses (a) the overall effectiveness of psychotherapy for depressed clients, (b) its effectiveness relative to pharmacotherapy, and (c) the clinical significance of treatment outcomes. Findings from the review confirm that depressed clients benefit substantially from psychotherapy, and these gains appear comparable to those observed with pharmacotherapy. Initial analysis suggested some differences in the efficacy of various types of treatment; however, once the influence of investigator allegiance was removed, there remained no evidence for the relative superiority of any 1 approach. In view of these results, the focus of future research should be less on differentiating among psychotherapies for depression than on identifying the factors responsible for improvement. Depression is a prevalent clinical disorder with high economic and emotional costs. Epidemiological research has indicated that 10%-20% of the population experience a major depressive episode at some point in their lifetime (Boyd & Weissman, 1981), with the incidence highest during the adult years when family and career responsibilities may be most adversely affected (Weissman & Myers, 1978). Although the remission rate for depressive disorders is relatively high (Beck, 1967, chap. 3), a substantial portion of those afflicted remain chronically depressed (Weissman & Klerman, 1977), and those who do improve are at an increased risk for further episodes (Belsher & Costello, 1988;Kessler, 1978; Klerman, 1978). Until recently, depression was treated almost exclusively with medication, traditional insight-oriented therapy, or a combination of the two. However, the 1970s witnessed the development of a number of new therapeutic approaches, each of which pos
This review quantitatively assesses the outcomes of psychotherapy with children. Seventy-five studies were examined in which children who received psychotherapy were compared with controls or children receiving another form of treatment. Results demonstrated that therapy with children is similar in effectiveness to therapy with adults; treated children achieved outcomes about two thirds of a standard deviation better than untreated children. Although behavioral treatments appeared to be more effective than nonbehavioral treatments, this apparent superiority was due largely to the types of outcome and target problems included in behavioral studies. No differences in outcome were found to result from other treatment characteristics such as the use of play in therapy or the administration of treatment individually or in groups. The evidence from this review suggests that previous doubts about the overall efficacy of psychotherapy with children can be laid to rest.
Osteopontin (Opn) is a secreted adhesive, glycosylated phosphoprotein that contains the arginine-glycine-aspartic acid (RGD) cell-binding sequence that is found in many extracellular matrix (ECM) proteins (for a review of Opn see References Denhardt & Guo 1993; Patarca et al. 1993; Rittling & Denhardt 1999). Since its initial description in 1979 as a secreted protein associated with malignant transformation, Opn has been independently discovered by investigators from diverse scientific disciplines, and has been associated with a remarkable range of pathologic responses. Opn is an important bone matrix protein, where it is thought to mediate adhesion of osteoclasts to resorbing bone. However, studies from the past decade have identified an alternative role for Opn as a key cytokine regulating tissue repair and inflammation. Recent work by our laboratory and that of others has underlined the importance of Opn as a pivotal cytokine in the cellular immune response. Despite this Opn is not well known to the immunologist. In this review we will focus on studies that pertain to the role of Opn in cell-mediated and granulomatous inflammation.
We examined 17 meta‐analyses of comparisons of active treatments with each other, in contrast to the more usual comparisons of active treatments with controls. These meta‐analyses yielded a mean uncorrected absolute effect size for Cohen's d of .20, which is small and non‐significant (an equivalent Pearson's r would be. 10). The smallness of this effect size confirms Rosenzweig's supposition in 1936 about the likely results of such comparisons. In the present sample, when such differences were corrected for the therapeutic allegiance of the researchers involved in comparing the different psychotherapies, these differences tend to become even further reduced in size and significance, as shown previously by Luborsky, Diguer, Seligman, et al. (1999).
This report examines a possible distortion in the results of comparative treatment studies due to the association of the researcher's treatment allegiances with outcomes of those treatments. In eight past reviews a trend appeared for significant associations between the researcher's allegiance and outcomes of treatments compared. In a new review of 29 studies of treatment comparisons, a similar trend appeared. Allegiance ratings were based not only on the usual reprint method, but also on two new methods: ratings by colleagues who knew the researcher well, and self‐ratings by the researchers themselves. The two new allegiance methods Interco related only moderately, but each allegiance measure correlated significantly with outcomes of the treatments compared, and when combined, the three measures explained 69% of the variance in outcomes Such an association can distort comparative treatment results. Our report concludes with how the researcher's allegiance may become associated with treatment outcomes and how studies should deal with these associations.
Chronic inflammation and granuloma formation are associated with mononuclear cell infiltrates and are characteristic pathologic responses in tuberculosis. To identify host cell genes involved in tuberculous pathology, we screened macrophage cDNA libraries for genes induced by mycobacterial infection. One gene isolated in this screen, osteopontin (also known as early T lymphocyte activation protein 1 or Eta-1), was of particular interest because it is a cytokine and macrophage chemoattractant. Further study revealed that Mycobacterium tuberculosis infection of primary human alveolar macrophages causes a substantial increase in osteopontin gene expression. Osteopontin protein was identified by immunohistochemistry in macrophages, lymphocytes, and the extracellular matrix of pathologic tissue sections of patients with tuberculosis. Increased osteopontin expression also was found to be associated with silicosis, another granulomatous disease. The association of osteopontin with granulomatous pathology, together with the known properties of the protein, suggest that osteopontin may participate in granuloma formation. The strategy of identifying host genes whose expression is altered by infection thus can provide valuable clues to disease mechanisms and will be increasingly valuable as additional human genome sequences become available.Mycobacterial infections are among the most numerous in the world, with Mycobacterium tuberculosis believed to have infected one-third of the world's population (1). Aggravating the worldwide pandemic have been the emergence of resistant organisms and the concurrent HIV epidemic. These events have renewed interest in understanding the fundamental biology of the interactions between pathogenic mycobacteria and their host.Exposure to M. tuberculosis can lead to a pulmonary infection characterized by macrophage recruitment to the site of infection, followed in many cases by granuloma formation (2-4). M. tuberculosis is a facultative intracellular pathogen whose cellular habitat is the macrophage (5-9). Thus, the M. tuberculosis-macrophage relationship is of considerable interest. Previous investigations have revealed that interleukin 1, tumor necrosis factor-␣, interleukin 6, transforming growth factor-, and interleukin 8 production by macrophages is increased by exposure to mycobacteria (10)(11)(12)(13)(14). Negative effects of mycobacteria on macrophage antigen presentation (15) and responsiveness to cytokines (16, 17) also have been documented. However, little is known about the molecular mechanisms involved in granuloma formation.To gain insight into the host response to tuberculosis, we used differential screening of cDNA libraries to compare mRNAs of infected and uninfected macrophages. We reasoned that the identification of macrophage genes whose expression is altered after phagocytosis of M. tuberculosis might provide clues to pathogenesis. Using a model system that used a macrophage cell line (18, 19), we surveyed the population of macrophage mRNAs for those altered by my...
The efficacy of cognitive behavior therapies was assessed in a quantitative review. Analysis based on 48 studies indicated that cognitive behavior therapies were superior to no treatment; however, there was no firm evidence that these therapies were superior to other psychotherapies. Our analyses failed to find cognitive behavior therapies emphasizing behavioral techniques to be more effective than primarily cognitive approaches. Also, the efficacy of cognitive behavior therapies appeared relatively uniform across diagnostic categories and equally effective when administered in a group or individual format. Additional evidence would be necessary to justify the contention that cognitive behavior therapies are either better than other psychotherapies or the treatment of choice for particular disorders.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.