We have identified two compounds that inhibit the expression of endothelial-leukocyte adhesion molecules intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin. These compounds act by inhibiting tumor necrosis factor-␣-induced phosphorylation of IB-␣, resulting in decreased nuclear factor-B and decreased expression of adhesion molecules. The effects on both IB-␣ phosphorylation and surface expression of E-selectin were irreversible and occurred at an IC 50 of approximately 10 M. These agents selectively and irreversibly inhibited the tumor necrosis factor-␣-inducible phosphorylation of IB-␣ without affecting the constitutive IB-␣ phosphorylation. Although these compounds exhibited other activities, including stimulation of the stress-activated protein kinases, p38 and JNK-1, and activation of tyrosine phosphorylation of a 130 -140-kDa protein, these effects are probably distinct from the effects on adhesion molecule expression since they were reversible. One compound was evaluated in vivo and shown to be a potent anti-inflammatory drug in two animal models of inflammation. The compound reduced edema formation in a dose-dependent manner in the rat carrageenan paw edema assay and reduced paw swelling in a rat adjuvant arthritis model. These studies suggest that inhibitors of cytokine-inducible IB␣ phosphorylation exert anti-inflammatory activity in vivo.The adhesion of circulating leukocytes to vascular endothelium is critical to inflammatory responses (reviewed in Refs. 1-3). Interaction of the selectin family of adhesion proteins and lectin counter-receptors is the predominant mechanism mediating initial adhesion between leukocytes and the vessel wall. The expression of endothelial-leukocyte adhesion molecule-1 (E-selectin, CD62E), vascular cell adhesion molecule-1 (VCAM-1, 1 CD106), and intercellular adhesion molecule-1 (ICAM-1, CD54) on the surface of endothelial cells is elevated at sites of inflammation (2, 4). Induction of these molecules by tumor necrosis factor-␣ (TNF␣) and other inflammatory cytokines is regulated at the level of gene transcription and requires binding of the transcription factor nuclear factor-B (NF-B) to the regulatory regions within the promoters of each of these genes (5-12).The NF-B/Rel transcription factor family plays an important role in cytokine-induced gene activation (13-15). The Rel family includes p50 (NFKB1), p52 (NFKB2), p65 (RelA), RelB, v-Rel, and c-Rel. In endothelial cells, the p50⅐p65 heterodimer is the predominant species that binds to B consensus sequences in the VCAM-1, ICAM-1, and E-selectin genes and activates gene transcription. NF-B is located in the cytoplasm of cells in an inactive form in association with the inhibitor IB-␣. In response to TNF␣ stimulation, IB-␣ is phosphorylated on 2 serine residues (Ser-32 and Ser-36), ubiquitinated, and degraded by a proteosome-dependent pathway allowing active NF-B to translocate to the nucleus where it can activate gene expression (16 -23). Many NF-B-dependent genes including the adhesion m...

CBP (CREB-binding protein) and p300 are versatile coactivators that link transcriptional activators to the basal transcriptional apparatus. In the present study, we identify CBP and p300 as coactivators of the nuclear factor-B (NF-B) component p65 (RelA). Consistent with their role as coactivators, both CBP and p300 potentiated p65-activated transcription of E-selectin and VCAM-1-CAT reporter constructs. The N-and C-terminal domains of both CBP͞p300 functionally interact with a region of p65 containing the transcriptional activation domain as demonstrated by mammalian two-hybrid assays. Direct physical interactions of CBP͞p300 with p65 were demonstrated by glutathione Stransferase fusion protein binding, and coimmunoprecipitation͞Western blot studies. The adenovirus E1A 12S protein, which complexes with CBP and p300, inhibited p65-dependent gene expression. Reporter gene expression could be rescued from E1A inhibition by overexpression of CBP or p300. CBP and p300 act as coactivators of p65-driven gene activation and may play an important role in the cytokine-induced expression of various immune and inf lammatory genes.

Understanding the common practices in the management of canine acute intervertebral disc herniation can provide a springboard for future discussions regarding the best practices in diagnosing and treating this disease.

Transcriptional repressor proteins play essential roles in controlling the correct temporal and spatial patterns of gene expression in Drosophila melanogaster embryogenesis. Repressors such as Knirps, Krüppel, and Snail mediate short-range repression and interact with the dCtBP corepressor. The mechanism by which short-range repressors block transcription is not well understood; therefore, we have undertaken a detailed structure-function analysis of the Knirps protein. To provide a physiological setting for measurement of repression, the activities of endogenous or chimeric Knirps repressor proteins were assayed on integrated reporter genes in transgenic embryos. Two distinct repression functions were identified in Knirps. One repression activity depends on dCtBP binding, and this function maps to a C-terminal region of Knirps that contains a dCtBP binding motif. In addition, an N-terminal region was identified that represses in a CtBP mutant background and does not bind to the dCtBP protein in vitro. Although the dCtBP protein is important for Knirps activity on some genes, one endogenous target of the Knirps protein, the even-skipped stripe 3 enhancer, is not derepressed in a CtBP mutant. These results indicate that Knirps can utilize two different pathways to mediate transcriptional repression and suggest that the phenomenon of short-range repression may be a combination of independent activities.Transcriptional repression is a critical component of genetic regulation during development, and the Drosophila melanogaster embryo has served as an important model for elucidation of basic repression mechanisms (7,19). Differential gene expression in the early embryo is controlled in large part by the activity of repressor proteins encoded by gap, pair-rule, and other genes (42, 45). Repression of transcription can involve reactions occuring off the DNA, such as the formation of inactive heteromeric complexes. Another mechanism involves competition between activators and repressors for binding sites on DNA. DNA-binding repressors that function by mechanisms other than competitive binding have been termed active repressors (24).An active repressor can repress basal promoters or enhancer elements over a short range (Ͻ100 bp) or, alternatively, over long ranges (Ͼ1,000 bp) (7,17). One model of repression in the embryo suggests that the short-range-long-range distinction results from the recruitment of distinct classes of cofactors (36, 55). Short-range repressors may interact with dCtBP, while long-range repressors interact with Groucho.Long-range repressors are typified by the Hairy protein, a transcription factor that binds the Groucho cofactor (5, 27, 40). Long-range repression complexes regulating the dpp, tld, and zen genes also recruit Groucho (7, 27), as do Engrailed, Runt, and dTCF, Drosophila repressors whose range of action has not yet been determined (3, 9, 50).Short-range repressors present in the early Drosophila em-

Intervertebral disc extrusion (IVDE) is one of the most common neurologic problems encountered in veterinary clinical practice. The purpose of this manuscript is to provide an overview of the literature related to treatment of acute canine thoracolumbar IVDE to help construct a framework for standard care of acute canine thoracolumbar IVDE where sufficient evidence exists and to highlight opportunities for future prospective veterinary clinical research useful to strengthen care recommendations in areas where evidence is low or non-existent. While there exist a number of gaps in the veterinary literature with respect to standards of care for dogs with acute thoracolumbar IVDE, recommendations for standard care can be made in some areas, particularly with respect to surgical decompression where the currently available evidence supports that surgery should be recommended for dogs with nonambulatory paraparesis or worse. While additional information is needed about the influence on timing of decompression on outcome in dogs that are deep pain negative for longer than 48 h duration, there is no evidence to support treatment of the 48 h time point as a cut off beyond which it becomes impossible for dogs to achieve locomotor recovery. Surgical decompression is best accomplished by either hemilaminectomy or mini-hemilaminectomy and fenestration of, at a minimum, the acutely ruptured disc. Adjacent discs easily accessed by way of the same approach should be considered for fenestration given the evidence that this substantially reduces future herniation at fenestrated sites. Currently available neuroprotective strategies such as high does MPSS and PEG are not recommended due to lack of demonstrated treatment effect in randomized controlled trials, although the role of anti-inflammatory steroids as a protective strategy against progressive myelomalacia and the question of whether anti-inflammatory steroids or NSAIDs provide superior medical therapy require further evaluation.