Promoter regions involved in density-dependent regulation of basic fibroblast growth factor gene expression in human astrocytic cells.

Expression of mitogenic basic fibroblast growth factor (bFGF) in the central nervous system is inhibited by direct cell contact and is implicated in reactive and neoplastic transformation of astrocytes. The molecular mechanisms controlling expression of bFGF were examined in cultures of human astrocytes. Cell-density-dependent depletion of bFGF mRNA levels parallels changes in bFGF gene protein. Regulation of transcription of a bFGF luciferase reporter gene containing an upstream region (bp -1800 to +314) of the bFGF gene promoter mimicks the density-dependent regulation of the endogenous bFGF gene in transfected astrocytes. Deletion analysis has identified a fragment (bp -650 to -513) and sequences further downstream (bp -274 to +314) as the regions required for the regulation of bFGF gene activity by cell density. Unlike in astrocytes, changing the cell density of glioma cell cultures does not affect the levels of bFGF protein and mRNA. bFGF luciferase constructs were expressed at the same level in high- or low-density cultures of glioma cells, indicating altered regulation of the bFGF gene promoter. Electrophoretic mobility shift assays showed binding of nuclear proteins to a fragment of bFGF gene promoter from bp -650 to -453. This binding was abolished by a deletion of the upstream cell-density-responsive region (bp -650 to -512). Binding was observed with nuclear extracts from subconfluent astrocytes but was reduced in extracts from confluent astrocytes. Our results indicate that induction of bFGF in astrocytes upon reduction of cell density is mediated transcriptionally by positive trans-acting factors interacting with bFGF promoter. In contrast, nuclear proteins from glioma cells bind to the promoter region from bp -650 to -453 independent of cell density. Thus, the constitutive binding of trans-acting factor(s) to the region of the bFGF promoter from bp -650 to -453 may be responsible for the continuous expression of bFGF that leads to the uncontrolled growth of glioma cells.

Preferential self-association of basic fibroblast growth factor is stabilized by heparin during receptor dimerization and activation.

Central to signaling by fibroblast growth factors (FGFs) is the oligomeric interaction of the growth factor and its high-affinity cell surface receptor, which is mediated by heparin-like polysaccharides. It has been proposed that the binding of heparin-like polysaccharides to FGF induces a conformational change in FGF, resulting in the formation of FGF dimers or oligomers, and this biologically active form is 'presented' to the FGF receptor for signal transduction. In this study, we show that monomeric basic FGF (FGF-2) preferentially self-associates and forms FGF-2 dimers and higher-order oligomers. As a consequence, FGF-2 monomers are oriented for binding to heparin-like polysaccharides. We also show that heparin-like polysaccharides can readily bind to self-associated FGF-2 without causing a conformational change in FGF-2 or disrupting the FGF-2 self-association, but that the bound polysaccharides only additionally stabilize the FGF-2 self-association. The preferential self-association corresponds to FGF-2 translations along two of the unit cell axes of the FGF-2 crystal structures. These two axes represent the two possible heparin binding directions, whereas the receptor binding sites are oriented along the third axis. Thus, we propose that preferential FGF-2 self-association, further stabilized by heparin, like "beads on a string," mediates FGF-2-induced receptor dimerization and activation. The observed FGF-2 self-association, modulated by heparin, not only provides a mechanism of growth factor activation but also represents a regulatory mechanism governing FGF-2 biological activity.

Exit from G0 and entry into the cell cycle of cells expressing p21Sdi1 antisense RNA.

p21Sdi1 (also known as Cip1 and Waf1), an inhibitor of DNA synthesis cloned from senescent human fibroblasts, is an inhibitor of G1 cyclin-dependent kinases (Cdks) in vitro and is transcriptionally regulated by wild-type p53. In addition, p21Sdi1 has been found to inhibit DNA replication by direct interaction with proliferating cell nuclear antigen. In this study we analyzed normal human fibroblast cells arrested in G0 and determined that an excess of p21Sdi1 was present after immunodepletion of various cyclins and Cdks, in contrast to mitogen-stimulated cells in early S phase. Expression of antisense p21Sdi1 RNA in G0-arrested cells resulted in induction of DNA synthesis as well as entry into mitosis. These results suggest that p21Sdi1 functions in G0 and early G1 and that decreased expression of the gene is necessary for cell cycle progression.

Interferons alpha and beta down-regulate the expression of basic fibroblast growth factor in human carcinomas.

We investigated the influence of interferons alpha, beta, and gamma (IFN-alpha, -beta, and -gamma) on the production of basic fibroblast growth factor (bFGF) by human renal carcinoma cells. The human renal carcinoma cell metastatic line SN12PM6 was established in culture from a lung metastasis and SN12PM6-resistant cells were selected in vitro for resistance to the antiproliferative effects of IFN-alpha or IFN-beta. IFN-alpha and IFN-beta, but not IFN-gamma, down-regulated the expression of bFGF at the mRNA and protein levels by a mechanism independent of their antiproliferative effects. Down-regulation of bFGF required a long exposure (> 4 days) of cells to low concentrations (> 10 units/ml) of IFN-alpha or IFN-beta. The withdrawal of IFN-alpha or IFN-beta from the medium permitted SN12PM6-resistant cells to resume production of bFGF. The incubation of human bladder, prostate, colon, and breast carcinoma cells with noncytostatic concentrations of IFN-alpha or IFN-beta also produced down-regulation of bFGF production.

The Trail of No Tears: Traditional Masculinity Ideologies and The Cycle of Dismissing-Avoidant Attachment

Raising boys in accordance with traditional masculinity ideologies is creating a mental health crisis among men. Socialization in accordance with traditional male gender roles causes boys to develop dismissing-avoidant attachments with their primary caregivers. Approaching subsequent relationships with a dismissing-attachment style creates disconnection between men and male peers, female partners, and their children. Many researchers advocate clinical interventions that perpetuate men's traditional fears of intimacy, however attachment theory provides an alternative lens through which clinicians may approach therapy with men. By engaging men in therapeutic attachment relationships, clinicians can inspire implicit and explicit learning of new attachment patterns. This experience by nature challenges traditional definitions of masculinity, and men may develop more congruent, adaptive, and healthy definitions of masculinity.

Sex, sin and salvation : a case study of the narrative pictorial cycle of Saint Mary the Egyptian at Bourges Cathedral

This paper studies the narrative stained glass cycle of the Life of Saint Mary the Egyptian at Bourges Cathedral within the context of prevailing—and often conflicting--civil and ecclesiastical attitudes toward sex, sexual sin, and prostitution in early thirteenth century France. Although the Church maintained that sexual sin was mortal sin, civil records suggest the public was skeptical. Through the example of a penitent harlot, this window, both structurally and in thematic content, attempts to map a doctrinally appropriate path from sexual sin to purity of spirit—and salvation—through complete submission to the Church and its clergy.

Effects of Dialogic Reading in the Improvement of Reading Comprehension in Students of Primary Education

Reading is an essential factor for success at school that requires certain skills and strategies of great complexity rarely taught in schools. Verbalization of comprehension strategies can be considered an effective measure in learning to read. The purpose of this study was to analyze the effect of a program of teaching reading strategies implemented through interactive dialogic reading groups in the learning of reading comprehension. A quasi-experimental comparison with pretest and posttest design between groups was used. A sample of 355 participants aged between 8 and 9 years aged was used. The results weigh the potential value of the program and support the development of teaching models that integrate dialogic reading practices as they facilitate learning of reading comprehension.

Records of the Society for the Promotion of Theological Education at Harvard University, 1788-1853 (inclusive), 1816-1853 (bulk)

Includes minutes and other records, 1816-1829, of the trustees of the Society and other correspondence relating to the founding of the Society; treasurer's reports, 1843-1844, of J.G. Palfrey; lists of beneficiaries, 1824- 1830; and subscription receipts, 1819-1823. Also records regarding subscriptions for a professorship, 1828, an extract from the will of J.D. Williams, and legal matters. For more detailed information about records, see Harvard Archives LOCATION below.