Effect of a novel type of propolis and its chemical fractions on glucosyltransferases and on growth and adherence of mutans streptococci.

Flavonoids have been considered the main biologically active components in propolis. However, a new variety of flavonoid-free propolis was recently found and chemically classified as type 6. Because it showed activity against oral microorganisms, this study evaluated the effects of the crude ethanolic extract of this propolis and its chemical fractions on the activity of purified glucosyltransferases (GTFs) and on the growth and adherence of mutans streptococci.

1,4-dibenzylpiperazines possess anticocaine activity.

N,N-dibenzylpiperazines have high affinity for sigma receptors, and we aimed to increase their anticocaine activity by introducing substituents known to enhance such activity in other sigma ligands. Ligands with high affinity for sigma-1 receptors resulted, but their activity in attenuating cocaine-induced convulsions did not correlate with sigma-1 binding affinity, and may be more closely related to their sigma-2 binding affinities.

Experimental investigation of criteria for continuous variable entanglement.

We generate a pair of entangled beams from the interference of two amplitude squeezed beams. The entanglement is quantified in terms of EPR paradox and inseparability criteria, with both results clearly beating the standard quantum limit. We experimentally analyze the effect of decoherence on each criterion and demonstrate qualitative differences.

Effects of apigenin and tt-farnesol on glucosyltransferase activity, biofilm viability and caries development in rats.

Propolis, a resinous hive product secreted by Apis mellifera bees, has been shown to reduce the incidence of dental caries in rats. Several compounds, mainly polyphenolics, have been identified in propolis. Apigenin and tt-farnesol demonstrated biological activity against mutans streptococci.

Experimental demonstration of continuous variable polarization entanglement.

We report the experimental transformation of quadrature entanglement between two optical beams into continuous variable polarization entanglement. We extend the inseparability criterion proposed by Duan et al. [Phys.

Recruitment of heterogeneous nuclear ribonucleoprotein A1 in vivo to the LMP/TAP region of the major histocompatibility complex.

Sequences containing the matrix recognition signature were identified adjacent to the LMP/TAP gene cluster in the human and mouse major histocompatibility complex class II region. These sequences were shown to function as nuclear matrix attachment regions (MARs). Three of the five human MARs and the single mouse MAR recruit heterogeneous nuclear ribonucleoprotein A1 (hnRNP-A1) in vivo during transcriptional up-regulation of the major histocompatibility complex class II genes.

Fluorosis: is it really a problem?

Background: Scientists have noted an association between mottled enamel and fluoride exposure since the early 1900s. By the mid-1900s, they also recognized that fluoride intake was related to lower caries incidence. To harness the protective effect of fluoride while limiting the occurrence of fluorosis, dental researchers have recommended that the fluoride level in chinking water be 1 part per million or less.

Hepatocytes undergo phenotypic transformation to biliary epithelium in organoid cultures.

Organoid cultures of hepatocytes in the presence of hepatocyte growth factor (HGF) and epidermal growth factor (EGF) display characteristic histologic organization. Biliary epithelium covers the surface of the tissue exposed to the culture medium. Hepatocytes, stellate cells and endothelial cells compose the underlying structures.

Involvement of sigma receptors in the behavioral effects of cocaine: evidence from novel ligands and antisense oligodeoxynucleotides.

Pharmacological and molecular biological tools were used to validate the involvement of sigma receptors in the actions of cocaine. Radioligand binding studies demonstrated significant levels of sigma receptors in the brain and heart, where cocaine interacts preferentially with the sigma(1) subtype. In behavioral pharmacological studies using mice, nine novel sigma receptor antagonists significantly attenuated cocaine-induced convulsions, while structural analogs with weak interactions with sigma receptors were ineffective.

The measurement of Bacillus mycoides spore adhesion using atomic force microscopy, simple counting methods, and a spinning disk technique.

An atomic force microscope has been used to study the adhesion of Bacillus mycoides spores to a hydrophilic glass surface and a hydrophobic-coated glass surface. AFM images of spores attached to the hydrophobic-coated mica surface allowed the measurement of spore dimensions in an aqueous environment without desiccation. The spore exosporium was observed to be flexible and to promote the adhesion of the spore by increasing the area of spore contact with the surface.

Do we need to be concerned about dental caries in the coming millennium?

Dental caries continues to be a pubic health problem despite claims that 50% of schoolchildren are caries-free. There are widespread variations in the prevalence of caries worldwide. Caries lesions are the clinical manifestation of a pathogenic process that may have been occurring on the tooth surface for months or years.

HnRNP-A1 binds directly to double-stranded DNA in vitro within a 36 bp sequence.

The heterogeneous nuclear ribonucleoprotein A1 (hnRNP-A1) is known as an RNA- and single-stranded DNA-binding protein involved in alternative splicing of mRNA, RNA transport and maintenance of chromosome telomere length. In this study we tested whether this protein could bind directly to double-stranded DNA (dsDNA). Using PCR amplification of target DNA-sequences from human chromosome 11q13 followed by their incubation with hnRNP-A1 and atomic force microscopy (AFM) of the DNA/protein complexes, we found that this protein bound to DNA within a 36 bp sequence.

sigma(2) Receptors regulate changes in sphingolipid levels in breast tumor cells.

sigma(2) Receptors induce apoptosis in various cell types. The sphingolipid, ceramide as well as the sphingoid bases are involved in cell proliferation. Sphingolipids of MCF-7/Adr- and T47D breast tumor cells were metabolically radiolabeled.

Lactoperoxidase inhibits glucosyltransferases from Streptococcus mutans in vitro.

This study examines the possible effect of the antimicrobial peroxidase system on the activity of streptococcal glucosyltransferases B, C and D (GtfB, GtfC and GtfD), either in solution (GtfB and GtfC) or when adsorbed to hydroxyapatite (GtfC and GtfD) at pH 6.5. The lactoperoxidase (LP) system (LP, H(2)O(2), SCN(-)) had no effect on the activity of dissolved GtfC, but the activity of dissolved GtfB was enhanced.

Influence of antibody on the structure of glucans.

Glucosyltransferase (GTF) plays an essential role in the formation of the biofilm known as dental plaque and in the pathogenesis of dental caries. Mutans streptococci produce at least three distinct GTFs (GtfB, C and D), each of which forms a glucan polymer from sucrose. Glucan is a major constituent of plaque biofilm.

Effects of compounds found in propolis on Streptococcus mutans growth and on glucosyltransferase activity.

Propolis, a resinous bee product, has been shown to inhibit the growth of oral microorganisms and the activity of bacterium-derived glucosyltransferases (GTFs). Several compounds, mainly polyphenolics, have been identified in this natural product. The present study evaluated the effects of distinct chemical groups found in propolis on the activity of GTF enzymes in solution and on the surface of saliva-coated hydroxyapatite (sHA) beads.

Hepatocyte growth factor induces Wnt-independent nuclear translocation of beta-catenin after Met-beta-catenin dissociation in hepatocytes.

Hepatocyte growth factor (HGF) and Wnt signaling pathways have been shown to be important in embryogenesis and carcinogenesis. The aim of this study was to elucidate the mechanism of functional similarities observed in the two pathways. We used normal rat liver, primary hepatocyte cultures and a dominant-negative Met expression system to study the effect of HGF on Wnt pathway components.

Polarization squeezing of continuous variable stokes parameters.

We report the first direct experimental characterization of continuous variable quantum Stokes parameters. We generate a continuous wave light beam with more than 3 dB of simultaneous squeezing in three of the four Stokes parameters. The polarization squeezed beam is produced by mixing two quadrature squeezed beams on a polarizing beam splitter.

Comparison of rRNA cleavage by complementary 1,10-phenanthroline-Cu(II)- and EDTA-Fe(II)-derivatized oligonucleotides.

The chemical nucleases 1,10-phenanthroline-Cu(II) and EDTA-Fe(II), have proven to be valuable tools for structural analysis of nucleic acids. Both have found applications in footprinting and directed proximity studies of DNA and RNA. Derivatives of each that provide for tethering to nucleic acid or protein are commercially available, allowing their widespread use for structural analysis of macromolecules.

N-arylalkylpiperidines as high-affinity sigma-1 and sigma-2 receptor ligands: phenylpropylamines as potential leads for selective sigma-2 agents.

To delineate the differences between the structural requirements necessary for recognition at sigma-1 and sigma-2 receptors, a range of phenethyl- and phenylpropylpiperidines were evaluated in binding assays. Phenethylpiperidines were found to favor sigma-1 receptors, whereas phenylpropylpiperidines tend to favor sigma-2 receptors. It appears that phenylpropylamine is a potential pharmacophore for selective sigma-2 ligands.

Sigma-2 receptor agonists activate a novel apoptotic pathway and potentiate antineoplastic drugs in breast tumor cell lines.

We have reported previously that sigma-2 receptors are expressed in high densities in a variety of tumor cell types (B. J. Vilner et al.

Caries inhibition efficacy of an antiplaque/antigingivitis dentifrice.

Purpose: To evaluate the efficacy of a fluoride dentifrice containing a fixed combination of essential oils (Thymol, Menthol, Eucalyptol, and Methyl Salicylate) in preventing caries in Sprague Dawley rats.

Materials And Methods: The dentifrice contains 0.76% sodium monofluorophosphate (SMFP) as the fluoride source and a silica abrasive system.

An analytical review of environmental justice research: what do we really know?

This article presents a review of major empirical research on environmental justice. Forty-two empirical research studies spanning three decades were evaluated and categorized on the basis of how well they meet reasonable scientific standards. Twelve of those studies are described and critiqued in detail, and an overview of trends in the literature is presented.

In vivo detection of postictal perturbations of cerebral metabolism by use of proton MR spectroscopy: preliminary results in a canine model of prolonged generalized seizures.

Background And Purpose: Biochemical studies of seizures in patients and laboratory animals have monitored postictal perturbations in cerebral metabolism with either invasive techniques or with such noninvasive techniques as nuclear medicine, MR imaging, in vivo phosphorus MR spectroscopy (MRS), and in vivo proton MRS at field strengths of 1.5 T or above. We investigated postictal metabolic changes in a generalized seizure model with in vivo proton MRS at 0.