Differential regulation of monocyte matrix metalloproteinase and TIMP-1 production by TNF-alpha, granulocyte-macrophage CSF, and IL-1 beta through prostaglandin-dependent and -independent mechanisms.

Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) produced by monocytes are believed to be involved in the migration of these cells through the basement membrane and the ensuing destruction of connective tissue in chronic inflammatory lesions. Because monocytes encounter a variety of cytokines at these sites, we examined the effect of cytokines either alone or in combination on the production of monocyte MMPs and TIMP-1. TNF-alpha, granulocyte-macrophage-CSF (GM-CSF), or IL-1 beta when added individually enhanced the endogenous levels of 92-kDa gelatinase (MMP-9) and TIMP-1 but failed to induce interstitial collagenase (MMP-1).

Expression, characterization, processing and immunogenicity of an insulin-dependent diabetes mellitus autoantigen, IA-2, in Sf-9 cells.

Autoantibodies to a 64-kD protein and a 40-kD tryptic fragment from pancreatic islets have been detected at high frequency in the sera of patients with insulin-dependent diabetes mellitus (IDDM). IA-2, a newly isolated transmembrane protein tyrosine phosphatase, is a major islet cell autoantigen in IDDM and the precursor of a 40-kD tryptic fragment. To express large quantities of recombinant IA-2 protein and analyse post-translational modifications we expressed full-length human IA-2 in baculovirus-infected Sf-9 cells.

Molecular and topological characterization of the rat parotid Na+-K+-2Cl- cotransporter1.

Na+-K+-2Cl- cotransporters play a central role in driving salt and water movements across secretory and absorptive epithelia. We report the cloning of the rat parotid secretory Na+-K+-2Cl- cotransporter, rtNKCC1. The predicted amino acid sequence of this protein is highly homologous to a previously cloned NKCC1 from the shark rectal gland and to mammalian NKCC1s cloned from several cultured cell lines, confirming the presence of the NKCC1 isoform in a naturally occurring mammalian secretory epithelium.

Targeted disruption of the biglycan gene leads to an osteoporosis-like phenotype in mice.

The resilience and strength of bone is due to the orderly mineralization of a specialized extracellular matrix (ECM) composed of type I collagen (90%) and a host of non-collagenous proteins that are, in general, also found in other tissues. Biglycan (encoded by the gene Bgn) is an ECM proteoglycan that is enriched in bone and other non-skeletal connective tissues. In vitro studies indicate that Bgn may function in connective tissue metabolism by binding to collagen fibrils and TGF-beta (refs 5,6), and may promote neuronal survival.

A conservative amino acid mutation in the chromosome-encoded dihydrofolate reductase confers trimethoprim resistance in Streptococcus pneumoniae.

Multidrug-resistant Streptococcus pneumoniae strains have emerged over the past decade at an alarming rate. The molecular mechanism of trimethoprim resistance was investigated in 5 pneumococcal strains isolated in the Washington, DC, area from patients with invasive infections. Cloning and sequencing of the trimethoprim resistance determinant from these pneumococci indicated that an altered chromosome-encoded dihydrofolate reductase (DHFR) was responsible for the observed resistance.

cDNA encoding a single-chain antibody to HIV p17 with cytoplasmic or nuclear retention signals inhibits HIV-1 replication.

HIV-1 gag p17 protein is an attractive target for molecular intervention, because it is involved in the viral replication cycle at both the pre- and postintegration levels. In the present experiments, we targeted p17 by intracellularly expressing a cDNA encoding an Ab to p17. cDNA from a hybridoma-secreting Ab to p17 was cloned, sequenced, reconstructed as a single-chain Ab fragment (scFv), and expressed in the cytoplasm or nucleus with appropriate retention signals.

Crevicular fluid level of beta-glucuronidase in relation to clinical periodontal parameters and putative periodontal pathogens in early-onset periodontitis.

Analysis of beta-glucuronidase (betaG) in the gingival crevicular fluid (GCF) provides an indication of neutrophil influx into the crevicular environment. The aim of this study was to test the hypotheses that: (1) betaG is significantly elevated in individuals with early-onset periodontitis (EOP) and that betaG activity correlates with disease severity; and (2) betaG level may reflect the local bacterial challenge in the gingival crevice. The study subjects consisted of a sub-sample of individuals examined in the National Survey of Oral Health of United States Children, which was undertaken during the 1986/87 school year.

Spinal kappa1 and kappa2 opioid binding sites in rats, guinea pigs, monkeys and humans.

Several lines of work demonstrate that there are two subtypes of kappa opioid receptors. Intrathecally administered agonists for the kappa1 subtype are not effective in treating pain, whereas agonists for the kappa2 receptor are anti-hyperalgesic and anti-allodynic. The question addressed here was whether the ratio of spinal kappa1 to kappa2 receptors was conserved across species.

Specific interaction of conformational polypeptides derived from HIV gp120 with human T lymphocyte CD4 receptor.

Specifically cross-linked peptides (peptomers) have been prepared from the repeating sequences of the C4 domains of glycoproteins 120 present in different isolates of human immunodeficiency virus (HIV). In order to investigate if the HIV C4 peptomers could function as gp120 protein, we have used a novel protein-binding assay to examine if and which components of the peptomers could interact with CD4 receptor in vitro. Here, we demonstrate that all the polymeric components of the HIV-1 C4 peptomer could bind to recombinant soluble CD4 protein.

Lipopolysaccharide induction of monocyte matrix metalloproteinases is regulated by the tyrosine phosphorylation of cytosolic phospholipase A2.

Activation of human monocytes with lipopolysaccharide (LPS) results in the production of matrix metalloproteinases (MMPs) through a prostaglandin E2 (PGE2)-cAMP-dependent pathway. In this study, the early signaling events involved in this signal transduction pathway were evaluated. Pretreatment of human peripheral blood monocytes with herbimycin A, a tyrosine kinase inhibitor, or arachidonyl trifluoromethyl ketone (AACOCF3), a specific inhibitor of cytosolic phospholipase A2 (cPLA2) inhibited the induction of PGE2 by LPS.

Green fluorescent protein labeling of cytoskeletal structures--novel targeting approach based on leucine zippers.

Green fluorescent protein (GFP) is a valuable marker for intracellular protein localization. However the fusion of GFP with structural proteins can alter their properties, resulting in a loss of fusion protein localization, decreased GFP fluorescence or both. We describe a novel targeting approach based on noncovalent heterodimerization of GFP and cytoplasmic structural proteins.

Contribution of regulation by the bvg locus to respiratory infection of mice by Bordetella pertussis.

Whooping cough is an acute respiratory disease caused by the small, gram-negative bacterium Bordetella pertussis. B. pertussis expresses several factors that contribute to its ability to cause disease.

The solution structure of ribosomal protein S4 delta41 reveals two subdomains and a positively charged surface that may interact with RNA.

S4 is one of the first proteins to bind to 16S RNA during assembly of the prokaryotic ribosome. Residues 43-200 of S4 from Bacillus stearothermophilus (S4 Delta41) bind specifically to both 16S rRNA and to a pseudoknot within the alpha operon mRNA. As a first step toward understanding how S4 recognizes and organizes RNA, we have solved the structure of S4 Delta41 in solution by multidimensional heteronuclear nuclear magnetic resonance spectroscopy.

The effect of fluoride on the size and morphology of apatite crystals grown from physiologic solutions.

In adult human bone, fluoride uptake is accompanied by an increase in apatite crystal size. This increase, however, is not isotropic but is restricted primarily to growth in width and/or thickness, with no measurable change in length. In the present study, seeded growth experiments were conducted in vitro to determine whether this anisotropic effect is physicochemical in origin, i.

p21(WAF1/Cip1) retards the growth of human squamous cell carcinomas in vivo.

The excessive proliferation exhibited by cancer cells is frequently a result of their failure to adequately regulate cell cycle progression. In the present study, we developed a xenograft model of oral cancer in athymic mice, using squamous carcinoma cell lines and examined the ability of the cyclin-dependent kinase inhibitor p21 (WAF1/Cip1) to retard tumour growth in vivo, using a retroviral delivery system. Human p21 cDNA was cloned by polymerase chain reaction, expressed, and the encoded protein shown to have biological activity in in vitro kinase assays.

Regulation of KCa current by store-operated Ca2+ influx depends on internal Ca2+ release in HSG cells.

This study examines the Ca2+ influx-dependent regulation of the Ca2+-activated K+ channel (KCa) in human submandibular gland (HSG) cells. Carbachol (CCh) induced sustained increases in the KCa current and cytosolic Ca2+ concentration ([Ca2+]i), which were prevented by loading cells with 1,2-bis(2-aminophenoxy)ethane-N,N,N', N'-tetraacetic acid (BAPTA). Removal of extracellular Ca2+ and addition of La3+ or Gd3+, but not Zn2+, inhibited the increases in KCa current and [Ca2+]i.

Dental fear and anxiety as a barrier to accessing oral health care among patients with special health care needs.

Persons with special health care needs due to physical and cognitive impairment can be at increased risk for dental disease which can be attributed to, as well as exacerbate, existing medical conditions. This study assessed the nature of perceived barriers to obtaining oral health care among a special-needs population and the influence of these factors (in particular, fear and anxiety) on utilization of dental services. A total of 27.

Laminin-alpha1-chain sequence Leu-Gln-Val-Gln-Leu-Ser-Ile-Arg (LQVQLSIR) enhances murine melanoma cell metastases.

We earlier screened overlapping synthetic peptides from the globular domain of the laminin alpha1 chain to identify active sites for cell attachment. We report here that one of the active cell-adhesion peptides, AG-73 (Arg-Lys-Arg-Leu-Gln-Val-Gln-Leu-Ser-Ile-Arg-Thr; RKRLQVQLSIRT) causes B16F10 murine melanoma cells to metastasize to the liver, a site not normally colonized by these cells. Increases in liver metastases and in lung colonization are observed in immune-deficient beige/nude/xid and in C57Bl/6 mice with this peptide.

Response to Weinstein: public health issues in early childhood caries.

Dr Weinstein's thoughtful overview of public health issues in early childhood caries (ECC) provides an excellent basis for further exploration. For public health to focus on a given problem several factors must be addressed: the disease must be widespread; the etiology or the prevention of the disease or condition must be known; this knowledge is not being applied; and resources for interventions must be available. Currently, appropriate data are not available for ECC and the problem is exacerbated because there is no case definition for the disease.

DNA sequence motifs are associated with aberrant homologous recombination in the mouse macrophage migration inhibitory factor (Mif) locus.

Homologous recombination is a precise genetic event that can introduce specific alteration in the genome. A planned targeted disruption by homologous recombination of the macrophage migration inhibitory factor (Mif) locus in mouse embryonic stem (ES) cells yielded the targeted clones, some of which had genomic rearrangements inconsistent with the expected homologous recombination event. A detailed characterization of the recombination breakpoints in two of these clones revealed several sequence motifs with possible roles in recombination.

Enhanced analgesia and suppression of plasma beta-endorphin by the S(+)-isomer of ibuprofen.

Background: Peripheral nociceptive barrage after tissue injury results in acute pain and a variety of physiologic responses, including pituitary secretion of beta-endorphin. This study evaluated whether administration of the pharmacologically active S(+)-isomer of ibuprofen suppresses acute pain and plasma beta-endorphin levels in the oral surgery model of acute pain.

Methods: Subjects in a single-dose, double-blind, parallel-group study received either 200 mg S(+)-ibuprofen, 400 mg S(+)-ibuprofen, 400 mg racemic ibuprofen, or placebo.

Cellular factors may enable squamous carcinoma cells to overcome TGF beta-mediated repression of CDK2 activity.

Cell lines developed from head and neck squamous cell carcinomas exhibit variable responses to the negative regulatory effects of transforming growth factor beta (TGF beta) on cell growth. To analyse the effects of TGF beta on regulators of cell cycle progression, we characterised cell lines derived from head and neck squamous cell carcinoma (HNSCC) for their biological sensitivities to TGF beta, growth inhibition, then examined the effects of TGF beta treatment on the expression and activity of cyclin dependent kinases (CDKs) and inhibitors of these kinases. Western blot analysis of cell lysates from untreated or TGF beta-treated cultures showed no alterations in expression of CDK2, CDK4, CDK6 or cyclin E in cell lines which were either sensitive (HaCaT, HN6) or refractory (HN12, HN30) to the growth-inhibitory effects of TGF beta.

To tame the pain?

Pain is still one of the most common reasons given by patients for avoiding dental care. Dental pain was identified as one of the most common pain complaints a national survey of pain in the US population. Although pain associated with dentistry encompasses intraoperative pain and pathologic pain as a result of dental neglect, it is likely that some of the aversion toward dentistry is a result of pain that occurs in the postoperative period.