Ampicillin and metronidazole treatment in preterm labour: a multicentre, randomised trial.
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Ampicillin↗
Biomedical subjects
T Collins
Publications and source records attributed to T Collins.
Endothelial interferon regulatory factor 1 cooperates with NF-kappa B as a transcriptional activator of vascular cell adhesion molecule 1.
Transcription of the vascular cell adhesion molecule 1 (VCAM-1) gene in endothelial cells is induced by lipopolysaccharide and the inflammatory cytokines interleukin-1 beta and tumor necrosis factor alpha (TNF-alpha). Previous studies have demonstrated that tandem binding sites for the inducible transcription factor NF-kappa B are necessary but not sufficient for full cytokine-mediated transcriptional activation. Herein, we demonstrate that full cytokine-induced accumulation of VCAM1 transcript requires protein synthesis. We report the definition of a functional regulatory element in the VCAM1 promoter interacting with the transcriptional activator interferon regulatory factor 1 (IRF-1). DNA-protein binding studies with endothelial nuclear extracts revealed that IRF-1 is cytokine inducible and binds specifically to a consensus sequence motif located 3' of the TATA element. We have identified heterodimeric p65 and p50 as the NF-kappa B species binding to the VCAM1 promoter in TNF-alpha-activated endothelial cells. Experiments with recombinant proteins showed that p50/p65 and high-mobility-group I(Y) protein cooperatively facilitated the binding of IRF-1 to the VCAM1 IRF binding site and that IRF-1 physically interacted with p50 and with high-mobility-group I(Y) protein. Transient transfection assay in endothelial cells showed that overexpressed IRF-1 resulted in superinduction of TNF-alpha-stimulated transcription. Site-directed mutations in the IRF binding element decreased TNF-alpha-induced activity and totally abolished superinduction. Cotransfection assays in P19 embryonal carcinoma cells revealed that IRF-1 synergized with p50/p65 NF-kappa B to activate the VCAM1 promoter or heterologous promoter constructs bearing isolated VCAM1 NF-kappa B and IRF binding motifs. Cytokine inducibility of VCAM1 in endothelial cells utilizes the interaction of heterodimeric p50/p65 proteins with IRF-1.
Base Sequence↗
Absence/hypoplasia of tibia, polydactyly, retrocerebellar arachnoid cyst, and other anomalies: an autosomal recessive disorder.
Absence or hypoplasia of the tibia has been reported to occur as an isolated hereditary malformation as well as a feature of several autosomal recessive and autosomal dominant syndromes. We report three sibs with absence or hypoplasia of the tibia in association with other malformations whose parents are first cousins once removed. These infants appear to have a "new" autosomal recessive syndrome.
Abnormalities, Multiple↗
Nuclear factor-kappa B interacts functionally with the platelet-derived growth factor B-chain shear-stress response element in vascular endothelial cells exposed to fluid shear stress.
Hemodynamic forces, such as fluid shear stress, that act on the endothelial lining of the cardiovascular system can modulate the expression of an expanding number of genes crucial for homeostasis and the pathogenesis of vascular disease. A 6-bp core element (5'-GAGACC-3'), defined previously as a shear-stress response element is present in the promoters of many genes, including the PDGF B-chain, whose expression is modulated by shear stress. The identity of the nuclear protein(s) binding to this element has not yet been elucidated. Using electrophoretic mobility shift assays and in vitro DNase I footprinting, we demonstrate that nuclear factor-kappa B p50-p65 heterodimers, which accumulate in the nuclei of cultured vascular endothelial cells exposed to fluid shear stress, bind to the PDGF-B shear-stress response element in a specific manner. Mutation of this binding motif abrogated its interaction with p50-p65 and abolished the ability of the promoter to mediate increased gene expression in endothelial cells exposed to shear stress. Transient cotransfection studies indicate that p50-p65 is able to activate PDGF-B shear-stress response element-dependent reporter gene expression in these cells. These findings thus implicate nuclear factor-kappa B in the transactivation of an endothelial gene responding to a defined fluid mechanical force.
Animals↗
Development and testing of nursing home quality indicators.
In this article, the authors report on the development and testing of a set of indicators of quality of care in nursing homes, using resident-level assessment data. These quality indicators (QIs) have been developed to provide a foundation for both external and internal quality-assurance (QA) and quality-improvement activities. The authors describe the development of the QIs, discuss their nature and characteristics, address the development of a QI-based quality-monitoring system (QMS), report on a pilot test of the QIs and the system, comment on methodological and current QI validation efforts, and conclude by raising further research and development issues.
Accidental Falls↗
Transcriptional regulation of endothelial cell adhesion molecules: NF-kappa B and cytokine-inducible enhancers.
Transcription of endothelial-leukocyte adhesion molecule-1 (E-selectin or ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) is induced by the inflammatory cytokines interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF alpha). The positive regulatory domains required for maximal levels of cytokine induction have been defined in the promoters of all three genes. DNA binding studies reveal a requirement for nuclear factor-kappa B (NF-kappa B) and a small group of other transcriptional activators. The organization of the cytokine-inducible element in the E-selectin promoter is remarkably similar to that of the virus-inducible promoter of the human interferon-beta gene in that both promoters require NF-kappa B, activating transcription factor-2 (ATF-2), and high mobility group protein I(Y) for induction. Based on this structural similarity, a model has been proposed for the cytokine-induced E-selectin enhancer that is similar to the stereospecific complex proposed for the interferon-beta gene promoter. In these models, multiple DNA bending proteins facilitate the assembly of higher order complexes of transcriptional activators that interact as a unit with the basal transcriptional machinery. The assembly of unique enhancer complexes from similar sets of transcriptional factors may provide the specificity required to regulate complex patterns of gene expression and correlate with the distinct patterns of expression of the leukocyte adhesion molecules.
Base Sequence↗
Novel cis-acting elements in the human platelet-derived growth factor B-chain core promoter that mediate gene expression in cultured vascular endothelial cells.
Platelet-derived growth factor (PDGF) is a potent mitogen and chemoattractant constitutively expressed by a variety of normal and transformed cells. Transient transfection and deletion analysis of the human c-sis proto-oncogene in cultured vascular endothelial cells revealed a minimal core promoter region extending 82 base pairs upstream from the TATA box. Two novel and functional cis-acting elements were identified within the core that share considerable sequence homology with consensus binding elements for transacting factors of the ETS class and those involved in AP-1 complexes. Deletion or mutation of either the ETS-like site or the AP-1-like site resulted in significant attenuation in the ability of the core to drive transcription. Electrophoretic mobility shift assays revealed that proteins from bovine aortic and human umbilical vein endothelial nuclear extracts bound to these elements in a specific manner and that both sites were essential for protein binding. Ferguson analysis predicted a combined molecular mass of 153 kDa for these proteins. In addition, transient transfection, gel shift, and DNase I footprint analysis were used to identify a functional Sp1 binding site downstream of these elements in the core promoter. By localizing the functional cis-acting elements in the PDGF-B promoter, it may be possible to elucidate the normal transcriptional control of the gene, as well as the mechanisms that activate it in pathologic settings.
Animals↗
cAMP and tumor necrosis factor competitively regulate transcriptional activation through and nuclear factor binding to the cAMP-responsive element/activating transcription factor element of the endothelial leukocyte adhesion molecule-1 (E-selectin) promoter.
The cAMP-responsive element/activating transcription factor (CRE/ATF) element (also known as NF-ELAM1) of the endothelial leukocyte adhesion molecule-1 (ELAM-1) promoter is necessary for full cytokine responsiveness. It differs from a consensus cAMP-responsive element (CRE) by 1 nucleotide (G-->A conversion) and does not mediate transcriptional activation in response to cAMP. We reported previously that cAMP actually decreases ELAM-1 synthesis induced by tumor necrosis factor (TNF). We now show that cAMP decreases the ELAM-1 promoter response to TNF in transient transfection assays in bovine aortic endothelial cells and that cAMP-mediated inhibition maps to the CRE/ATF element. Electrophoretic mobility shift assays using the ELAM-1 CRE/ATF DNA sequence reveal three complexes. Antibody supershift assays suggest the slowest migrating form (complex 1) contains ATF2, the middle form (complex 2) contains ATF2 and c-Jun, and the fastest migrating form (complex 3) contains a CRE-binding protein. TNF increases c-Jun-containing complex 2 while diminishing complex 1, whereas cAMP decreases complex 2 and increases complex 1. Complex 3 is unchanged by either treatment, and the CRE-binding protein is not phosphorylated. Our data suggest that a change in the composition of the proteins binding to the CRE/ATF promoter element contributes to the competing effects of TNF and cAMP on ELAM-1 gene expression.
Animals↗
NF-kappa B and I kappa B alpha: an inducible regulatory system in endothelial activation.
Structural analysis of the promoters of several endothelial genes induced at sites of inflammatory or immune responses reveals binding sites for the transcription factor nuclear factor kappa B (NF-kappa B). Endothelial cells express transcripts encoding the p50/p105 and p65 components of NF-kappa B and the rel-related proto-oncogene c-rel; steady state levels of these transcripts are transiently increased by tumor necrosis factor alpha (TNF-alpha). Western blotting revealed that stimulation of endothelial cells with TNF-alpha resulted in nuclear accumulation of the p50 and p65 components of NF-kappa B. Ultraviolet crosslinking and immunoprecipitation demonstrated binding of the p50 and p65 components of NF-kappa B to the E-selectin kappa B site. Endothelial cells express an inhibitor of NF-kappa B activation, I kappa B-alpha (MAD-3). Protein levels of this inhibitor fall rapidly after TNF-alpha stimulation. In parallel, p50 and p65 accumulate in the nucleus and RNA transcript levels for I kappa B-alpha are dramatically upregulated. Recombinant p65 stimulates expression of E-selectin promoter-reporter constructs. I kappa B-alpha inhibits p65 or TNF-alpha-stimulated E-selectin promoter-reporter gene expression in transfected endothelial cells. The NF-kappa B and I kappa B-alpha system may be an inducible regulatory mechanism in endothelial activation.
Animals↗
Intratracheal administration of endotoxin and cytokines: VIII. LPS induces E-selectin expression; anti-E-selectin and soluble E-selectin inhibit acute inflammation.
E-selectin is an inducible endothelial adhesion molecule that binds neutrophils. E-selectin mRNA is not constitutively detectable in the lungs of rats. Intratracheal injection of LPS induces pulmonary E-selectin mRNA expression at 2-4 h. Intratracheal injection of LPS followed at 2 and 4 h by intravenous injection of mouse F(ab')2 or F(ab') anti-E-selectin monoclonal antibody inhibits the emigration of neutrophils into the bronchoalveolar space at 6 h by 50-70%. TNF and IL-6 bioactivity are not decreased in bronchoalveolar lavage fluid after treatment with anti-E-selectin antibody as compared to controls, suggesting that the anti-E-selectin does not affect the magnitude of the LPS-initiated cytokine cascade. Intratracheal injection of LPS followed at 2 and 4 h by intravenous injection of soluble E-selectin inhibits neutrophilic emigration at 6 h by 64%, suggesting that endogenous soluble E-selectin shed from activated endothelium may play a role in the endogenous down-regulation of acute inflammation. E-selectin-mediated adhesion of neutrophils to endothelium appears crucial to the full development of the acute inflammation response.
Acute Disease↗
A striking similarity in the organization of the E-selectin and beta interferon gene promoters.
Transcription of the endothelial leukocyte adhesion molecule 1 (E-selectin or ELAM-1) gene is induced by the inflammatory cytokines interleukin-1 beta and tumor necrosis factor alpha (TNF-alpha). In this report, we identify four positive regulatory domains (PDI to PDIV) in the E-selectin promoter that are required for maximal levels of TNF-alpha induction in endothelial cells. In vitro DNA binding studies reveal that two of the domains contain novel adjacent binding sites for the transcription factor NF-kappa B (PDIII and PDIV), a third corresponds to a recently described CRE/ATF site (PDII), and a fourth is a consensus NF-kappa B site (PDI). Mutations that decrease the binding of NF-kappa B to any one of the NF-kappa B binding sites in vitro abolished cytokine-induced E-selectin gene expression in vivo. Previous studies demonstrated a similar correlation between ATF binding to PDII and E-selectin gene expression. Here we show that the high-mobility-group protein I(Y) [HMG I(Y)] also binds specifically to the E-selectin promoter and thereby enhances the binding of both ATF-2 and NF-kappa B to the E-selectin promoter in vitro. Moreover, mutations that interfere with HMG I(Y) binding decrease the level of cytokine-induced E-selectin expression. The organization of the TNF-alpha-inducible element of the E-selectin promoter is remarkably similar to that of the virus-inducible promoter of the human beta interferon gene in that both promoters require NF-kappa B, ATF-2, and HMG I(Y). We propose that HMG I(Y) functions as a key architectural component in the assembly of inducible transcription activation complexes on both promoters.
Activating Transcription Factor 2↗
Platelet-derived growth factor B chain promoter contains a cis-acting fluid shear-stress-responsive element.
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Animals↗
Platelet-derived growth factor B chain promoter contains a cis-acting fluid shear-stress-responsive element.
The endothelial lining of blood vessels is constantly exposed to fluid mechanical forces generated by flowing blood. In vitro application of fluid shear stresses to cultured endothelial cells influences the expression of multiple genes, as reflected by changes in their steady-state mRNA levels. We have utilized the B chain of platelet-derived growth factor (PDGF-B) as a model to investigate the mechanisms of shear-stress-induced gene regulation in cultured bovine aortic endothelial cells (BAECs). Northern blot analysis revealed elevated endogenous PDGF-B transcript levels in BAECs, after exposure to a physiological level of laminar shear stress (10 dynes/cm2; 1 dyne = 100 mN) for 4 h. A transfected reporter gene, consisting of a 1.3-kb fragment of the human PDGF-B promoter coupled to chloramphenicol acetyltransferase (CAT), indicated a direct effect on transcriptional activity. Transfection of a series of PDGF-B-CAT deletion mutants led to the characterization of a cis-acting component within the PDGF-B promoter that was necessary for shear-stress responsiveness. In gel-shift assays, overlapping oligonucleotide probes of this region formed several protein-DNA complexes with nuclear extracts prepared from both static and shear-stressed BAECs. A 12-bp component (CTCTCAGAGACC) was identified that formed a distinct pattern of complexes with nuclear proteins extracted from shear-stressed BAECs. This shear-stress-responsive element does not encode binding sites for any known transcription factor but does contain a core binding sequence (GAGACC), as defined by deletion mutation in gel-shift assays. Interestingly, this putative transcription factor binding site is also present in the promoters of certain other endothelial genes, including tissue plasminogen activator, intercellular adhesion molecule 1, and transforming growth factor beta 1, that also are induced by shear stress. Thus, the expression of PDGF-B and other pathophysiologically relevant genes in vascular endothelium appears to be regulated, in part, by shear-stress-induced transcription factors interacting with a common promoter element.
Animals↗
Structure of the murine VCAM1 gene.
The architecture of the murine VCAM1 gene, encoding vascular cell adhesion molecule-1, was determined. its 10 exons span approximately 20 kb. Exon 1 encodes the 5' untranslated region and the signal peptide; exons 2-4 and 6-9, the C2 or H-type immunoglobulin domains; and exon 10, the transmembrane and cytoplasmic domains followed by the entire 3' untranslated region. All immunoglobulin-like domains are encoded by separate exons, and exon splice junctions occur after the first nucleotide of amino acid codons (type 1). Exon 5 encodes a novel domain unique to murine VCAM-1 and inclusion of this exon by alternative splicing results in a truncated three-immunoglobulin-like domain form, which is bound to the cell membrane by a phosphatidylinositol linkage at its carboxy terminus (encoded by exon 5). The murine VCAM1 core promoter contains a high degree of homology to the human, including conserved consensus binding sites for NF-kappa B, the Ets class, and the GATA family of transcription factors, suggesting that the murine and human VCAM1 genes may be under similar transcriptional control.
Amino Acid Sequence↗
Detection of latent cytomegalovirus DNA in diverse organs of mice.
Latency is essential to the pathogenesis of cytomegalovirus (CMV) infection and disease. A survey of mouse organs that might contain latent murine CMV (MCMV) DNA was conducted using nested enzymatic amplification of a 200-bp region of exon 4 of the major immediate early gene 1. MCMV DNA was detected in diverse organs including the heart, kidney, liver, lung, spleen, brain, and salivary glands. The total number of organs in which latent MCMV DNA was detected was significantly greater in mice infected at 4 weeks of age (64/70) than in mice infected at 7 weeks of age (40/69). This phenomenon was associated with greater viral replication in the same organs during acute infection. These results indicate that latent MCMV infection is distributed much more widely than previously suspected and is directly correlated with the extent of viral replication during acute infection.
Age Factors↗
Differential regulation of vascular cell adhesion molecule 1 gene expression by specific NF-kappa B subunits in endothelial and epithelial cells.
Vascular cell adhesion molecule 1 (VCAM-1) is expressed in both endothelial and epithelial cell types, where it contributes to lymphocyte migration to sites of inflammation. Its expression is regulated by cytokines, in part through two kappa B-like regulatory elements. Because NF-kappa B can be composed of multiple alternative subunits with differential effects on gene expression, the role of different specific NF-kappa B family members subunits in VCAM-1 regulation is unknown. In this report, we define the contribution of different NF-kappa B family members to VCAM-1 gene regulation. We show that both kappa B sites in the VCAM-1 enhancer are required to optimally stimulate gene expression, but the enhancer is differentially regulated by specific combinations of NF-kappa B subunits. At low concentrations, RelA(p65) acted in concert with the approximately 50-kDa product of p105 NF-kappa B, NF-kappa B1(p50), to stimulate transcription, and at high concentrations, RelA(p65) alone stimulated the VCAM-1 promoter. In contrast, NF-kappa B2 inhibited functional activation of the VCAM reporter by p65. Consistent with this finding, an additional binding complex was detected by using recombinant NF-kappa B2(p49)/RelA(p65) with radiolabeled VCAM kappa B site probes. Interestingly, the human immunodeficiency virus enhancer responded differently to stimulation by NF-kappa B subunits, with optimal response to p49(100)/p65. Analysis of NF-kappa B mRNA in human umbilical vein endothelial cells revealed that nfkb1, nfkb2, and relA NF-kappa B but not c-rel were induced by tumor necrosis factor alpha and lipopolysaccharide, which also induce VCAM-1. These data suggest that specific subunits of NF-kappa B regulate VCAM-1 and differentially activate other genes in these cells.
Animals↗
Nd:YAG laser as a therapeutic option in the management of gastrointestinal cancer.
We report the use of ELT utilizing an Nd:YAG laser in a group of patients with cancer who represented a significant surgical risk. Effective palliation was achieved, with minimal morbidity, and the quality of life of most of our patients was preserved or enhanced, at a minimal physiologic cost. In carefully selected patients, ELT has proved to be a safe and highly effective procedure for the management of gastrointestinal cancers. It should be considered a valuable addition to the treatment armamentarium of the practicing clinician dealing with patients with advanced cancers or patients with significant medical conditions precluding surgical resection.
Aged↗
Expression of VCAM-1 and E-selectin in an in vivo model of endothelial activation.
Vascular cell adhesion molecule 1 (VCAM-1) and E-selectin (or endothelial-leukocyte adhesion molecule 1) are inducible endothelial cell adhesion molecules that play a role in the recruitment of leukocytes into sites of inflammation. Information about the spatial and temporal pattern of induced expression of these leukocyte adhesion molecules in vivo is limited. This study reports the expression profile of VCAM-1 and E-selectin in various mouse tissues after lipopolysaccharide administration. Using rat complementary DNA probes for VCAM-1 and E-selectin, Northern blot analysis showed a marked increase in transcript levels for both adhesion molecules in lung, heart, and kidney. Maximal transcript levels for both VCAM-1 and E-selectin were observed at 3-6 hours and declined to low, constitutive levels of expression at 48 hours. Consistent with the Northern blot results, immunoperoxidase analysis revealed focal endothelial cell expression of VCAM-1 in control animals. Following lipopolysaccharide administration, VCAM-1 expression increased dramatically in all vascular beds examined, although the response was heterogeneous. Widespread induced expression of VCAM-1 on cells other than vascular endothelium was not seen. Neither basal nor induced expression correlated with leukocyte adhesion. Signals other than the expression of endothelial leukocyte adhesion molecules are required in vivo for leukocyte infiltration in this murine model of systemic endothelial activation.
Amino Acid Sequence↗