Proteome analyses of human macrophages exposed to low cytotoxic IC90 copper (2+) ions.

Dental noble alloys often contain copper (Cu). Eluted metal ions sometimes irritate oral tissues. The most eluted ions are Cu ions.

High-cell density-induced VCAM1 expression inhibits the migratory ability of mesenchymal stem cells.

MSCs (mesenchymal stem cells) migrate into damaged tissue and then proliferate and differentiate into various cell lineages to regenerate bone, cartilage, fat and muscle. Cell-cell adhesion of MSCs is essential for the MSC-dependent tissue regeneration after their homing into a damaged tissue. However, it remains to be elucidated what kinds of adhesion molecules play important roles in the cell-cell communication between MSCs.

Relationship between oral status and prevalence of periodontopathic bacteria on the tongues of elderly individuals.

Colonization of periodontopathic bacteria is associated with increased risk of systemic diseases. However, few studies have investigated the relationships between oral status factors and health-related quality of life (HR-QOL) and the prevalence of such bacteria in elderly individuals. This study investigated the prevalence of Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola and Tannerella forsythia in 165 community-dwelling functionally independent 85-year-old Japanese individuals (93 dentate, 72 edentulous) and the relationship to oral status, including oral malodour and HR-QOL.

Viscoelastic behavior of commercially available tissue conditioners under compression.

Three commercially available tissue conditioners -Tissue conditioner II (STII), Tissue conditioner (GTC), and Tissue Care (TTC)- were tested using a rheometer to evaluate their viscoelasticity under compression at a constant distortion (10%). Immediately after fabrication, STII showed the highest hardness and compressive modulus of elasticity, followed by TTC and GTC. TTC showed the highest relaxation rate, followed by GTC and STII.

Production of indole from L-tryptophan and effects of these compounds on biofilm formation by Fusobacterium nucleatum ATCC 25586.

The l-tryptophan degradation product indole is a purported extracellular signaling molecule that influences biofilm formation in various bacteria. Here we analyzed the mechanisms of indole production in Fusobacterium nucleatum and the effects of tryptophan and indole on F. nucleatum planktonic and biofilm cells.

Production of hydrogen sulfide by two enzymes associated with biosynthesis of homocysteine and lanthionine in Fusobacterium nucleatum subsp. nucleatum ATCC 25586.

Fusobacterium nucleatum produces a large amount of the toxic metabolite hydrogen sulfide in the oral cavity. Here, we report the molecular basis of F. nucleatum H(2)S production, which is associated with two different enzymes: the previously reported Cdl (Fn1220) and the newly identified Lcd (Fn0625).

Viscoelastic adlayers of collagen and lysozyme studied using quartz crystal microbalance with dissipation monitoring.

In this study the effects of molecular structure of proteins on their adsorption behaviour and viscoelasticity are investigated using a QCM-D method. The adsorption measurements show that spherical lysozyme is rapidly adsorbed on the gold surface as a stiff monolayer, as indicated by a sharp drop in the oscillation frequency (Deltaf) of the sensor, and by a very small increase in the energy dissipation of the adlayer (DeltaD). Fibrous calfskin collagen (CSC) is, however, adsorbed on the same surface rather slowly in two steps to form a thick and soft multilayer (large Deltaf and DeltaD) at pH 3 in salt-free conditions.

Use of a novel assay to evaluate enzymes that produce hydrogen sulfide in Fusobacterium nucleatum.

To evaluate enzymes that produce hydrogen sulfide (H(2)S) in species of Fusobacterium nucleatum, we developed an assay based on SDS-polyacrylamide gel electrophoresis with renaturation followed by active staining. This assay provided precise insight into the enzymes that produce H(2)S in terms of their number and molecular weights.

Microscopic observations and inflammatory cytokine productions of human macrophage phagocytising submicron titanium particles.

This study was performed to microscopically observe and measure inflammatory cytokine production by human macrophages phagocytosing submicron titanium (Ti) particles. Observations with secondary electron microscopy (SEM), SEM/electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) indicated that macrophages [phorbol-12-myristate-13-acetate (PMA)-differentiated THP-1 cells] at 24 h in culture actively phagocytosed and accumulated submicron Ti particles in intracellular phagosomes, in which refinement of Ti particles occurred. The macrophages were also cultured for 24 h in four media with and without submicron Ti particles and lipopolysaccharide (LPS; components of bacteria).

Gene expression analyses of human macrophage phagocytizing sub-micro titanium particles by allergy DNA chip (Genopal).

The purpose of this study was to examine gene expressions of macrophage phagocytizing sub-micro Ti particles by a DNA chip. Human monocytic cell line THP-1 was differentiated into macrophages by culturing for two days in medium supplemented with 200 nM phorbol ester (PMA). The macrophages were then cultured in four media: medium without PMA (control); medium with suspended sub-micro Ti particles (0.

Identification and molecular characterization of tryptophanase encoded by tnaA in Porphyromonas gingivalis.

Indole produced via the beta-elimination reaction of l-tryptophan by pyridoxal 5'-phosphate-dependent tryptophanase (EC 4.1.99.

Preparation and in vivo evaluation of apatite/collagen packed composite by alternate immersion method and Newton press.

Further development of bio-compatible, bio-absorbable, and osteo-conductive bio-materials is desired for bone grafts in dental and medical clinics. One candidate material might be a high-density apatite/collagen composite, which cures relatively large bone defects. To produce such a composite, we freeze-dried type I collagen solution, cross-linked the formed sponge by 2 wt % glutaraldehyde, immersed the insoluble sponge in CaCl(2) and Na(2)HPO(4) solutions alternately five times, and compacted the sponge by Newton press at 5000 kgf.

Identification and molecular analysis of betaC-S lyase producing hydrogen sulfide in Streptococcus intermedius.

Hydrogen sulfide (H(2)S) is a toxic gas that induces the modification and release of haemoglobin in erythrocytes; however, it also functions in methionine biosynthesis in bacteria. betaC-S lyase, encoded by the lcd gene, is responsible for bacterial H(2)S production through the cleavage of l-cysteine. In this study, 26 of 29 crude extracts from reference and clinical strains of Streptococcus intermedius produced H(2)S from l-cysteine.

Effect of pH and addition of salt on the adsorption behavior of lysozyme on gold, silica, and titania surfaces observed by quartz crystal microbalance with dissipation monitoring.

The adsorption behaviors of lysozyme on dentally related Au, SiO2, and TiO2 surfaces were investigated by a quartz crystal microbalance with dissipation monitoring (QCM-D) method. Frequency shifts indicated that while lysozyme (pI 11) was fairly adsorbed on the SiO2 (pI 1.9) surface at both pH 3 and 7, it was adsorbed on TiO2 (pI 6.

Occurrence of staphylococci in the oral cavities of healthy adults and nasal oral trafficking of the bacteria.

To investigate a possible peroral route of infective endocarditis (IE), the occurrence of staphylococci in the oral cavity was examined using saliva and supragingival plaque specimens from 56 systemically and periodontally healthy adults aged 22-43 years old (27.1+/-5.3).

Dose-dependent effects of Ni (II) ions on production of three inflammatory cytokines (TNF-alpha, IL-1beta and IL-6), superoxide dismutase (SOD) and free radical NO by murine macrophage-like RAW264 cells with or without LPS-stimulation.

The effect of Ni (II) ions on macrophages is not well understood. The purpose of this study was to examine the dose-dependent effects of Ni (II) ions up to 1,000 micromol/L on production of three inflammatory cytokines (TNF-alpha, IL-1beta and IL-6), superoxide dismutase (SOD) and nitric oxide (NO) by murine macrophage-like RAW264 cells with (+) or without (-) lipopolysaccharide (LPS) -stimulation. Ni (II) ions caused LPS (-) RAW264 cells to slightly increase production of TNF-alpha and IL-6, proportionally to the Ni (II) ion concentration while IL-1beta was not produced, and to slightly increase production of SOD and NO.

New index for the stability of a type I collagen affected by hydrophobic environment.

Effects of hydrophobic environment adjusted by various alcohols on the structural stability of calfskin collagen (CSC) were studied to elucidate the nature of collagen-monomer interaction in adhesion. The stability of CSC in aqueous alcohol solutions was represented by its denaturation temperature, Td, measured by DSC. The hydrophobicity of the alcohol solutions was quantified with their specific dielectric constants, epsilon(r), calculated from their concentrations.

Accumulation of element Ti in macrophage-like RAW264 cells cultured in medium with 1 ppm Ti and effects on cell viability, SOD production and TNF-alpha secretion.

The adverse effect of Ti on body-defense macrophage is not well understood. The aims of this study were twofold: (1) to examine the intracellular accumulation of Ti element; and (2) to measure the cell viability, superoxide dismutase (SOD) production, and TNF-alpha secretion of macrophage-like RAW264 cells cultured for two days in medium with 1 ppm Ti prepared from acidic ICP Ti standard solution. PIXE analysis showed that element Ti was accumulated up to 7.

Sulfuration resistance of five experimental Ag-Pd-Au-Cu alloys with low Pd content of 10 or 12%.

Commercial Ag-based alloy (46Ag-20Pd-12Au-20Cu alloy) is widely used in Japan as a casting alloy. As opposed to the commercial composition, we prepared five experimental Ag-based alloys with reduced Pd content of 10 or 12%, increased Au content of 20 to 30%, and reduced Cu content of 12 to 20%. We then evaluated their sulfuration resistance by analyzing cast specimen surfaces dipped in 0.

Immunohistochemical reactions of receptors to met-enkephalin, VIP, substance P, and CGRP located on Merkel cells in the rat sinus hair follicle.

The role of Merkel cells in type I cutaneous mechanoreceptors remains enigmatic though mechanical transduction or neuromodulation function has been proposed. It has been shown that mammalian Merkel cells express immunohistochemical reactions of met-enkephalin, VIP, substance P, and CGRP, though the reactivity differs between species. If any one of these peptides acts as a transmitter or modulator for Merkel nerve terminals, these structures must have a specific receptor for the substance.

Regeneration of the epidermis and mucosal epithelium on the basement membranes.

The processes of degeneration and regeneration of the lip epidermis and mucosal epithelium after cryo treatment were observed by transmission electron microscopy. Epidermal and mucosal epithelial cells degenerated due to the formation of ice crystals and detached from the basement membranes, leaving a small amount of cell debris. Regenerating cells migrated over the cell debris, which was gradually phagocitized, and formed new hemidesmosomes with the preexisting lamina densa.

Streptococcus anginosus infection in oral cancer and its infection route.

Objective: To elucidate a possible involvement of Streptococcus anginosus in oral cancer, we assessed the frequency of S. anginosus infection in oral cancer tissues, and investigated its infection route.

Materials And Method: The tissue specimens were obtained from 46 oral cancer and three precancerous leukoplakia subjects.

Bio-sorption of acidic gelatine hydro-gels implanted in the back tissues of Fisher's rats.

Recent advance in tissue engineering therapy requires new scaffold materials. Acidic gelatine powders (10 wt%) were, thus, dissolved in water, were or were not cross-linked, and freeze-dried. After sterilization, prepared small sponges were implanted in 7-week-old Fisher's rats' subcutaneous tissues for up to 2 weeks.

Receptors and transporter for serotonin in Merkel cell-nerve endings in the rat sinus hair follicle. An immunohistochemical study.

Serotonin (5-HT) has been a candidate for neurotransmitters in cutaneous type I mechanoreceptors (i.e., Merkel cell-nerve endings).