Protection against copper-induced cytotoxicity by inclusion of gold.

Background: We previously reported that contact with copper (Cu) induced immediate cell death via an oxidation-involved mechanism, and the Cu-induced oxidation and cell death were effectively alleviated under hypoxic conditions. In order to explore alternative strategies for the protection from the Cu-induced cytotoxicity, we investigated whether the inclusion of gold (Au) in the Cu plate, as alloy,has a protective effect.

Materials And Methods: Human gingival fibroblast (HGF) cells, established from periodontal tissues, were inoculated on Au/Cu alloy of different Au ratios.

Changes in amino acid metabolism during activation of mouse macrophage-like cell lines.

Background: recent reports have suggested the applicability of salivary amino acids as markers for various diseases. In order to understand the role of macrophages in the age-related changes of salivary amino acid composition, we compared the amino acid production and consumption between control and activated macrophages.

Materials And Methods: mouse macrophage-like cells (RAW264.

Changes in salivary amino acid composition during aging.

Background: it has been suggested that the features of saliva reflect the physiological and psychological state of primates as well as subprimates, however, studies revealing the relationship between aging and the concentrations of salivary amino acids are limited. In order to better understand their physiological role, age-related changes of salivary amino acids were investigated.

Materials And Methods: forty-five participants including 5 children [6.

Diurnal changes in salivary amino acid concentrations.

It has been suggested that the features of saliva (e.g. fluidity, secretion and amino acid concentration) reflect physiological and psychological state of primates as well as subprimates, however, studies which revealed the relationship between the circadian rhythm and the concentrations of salivary amino acids have been limited.

Quantification of enhanced osteoblastic adhesion to ultraviolet-treated titanium plate.

Although the advantage of ultraviolet (UV) irradiation of titanium plates for the attachment of osteoblast is known, the details of the experimental conditions have not been described in previous literature. We established optimal conditions of UV irradiation of titanium plate for the adhesion of mouse osteoblast MC3T3-E1 cells. The viable cell number was determined by MTT method.

Effect of contact with titanium alloys on the proliferation of mouse osteoblastic cells in culture.

This study was aimed at studying the effect of contact with titanium alloy plates of different surface textures on the proliferative capability of mouse osteoblastic MC3T3-E1 cells. First, the proliferation characteristics of MC3T3-E1 cells were investigated. MC3T3-E1 cells showed a high capacity for proliferation and survived for a long period even under nutritionally starved conditions.

Non-apoptotic cell death induced by nutritional starvation in J774.1 mouse macrophage-like cell line.

The growth and amino acid utilization of a mouse macrophage-like cell line J774.1 was investigated in two different culture media supplemented with 10% fetal bovine serum (FBS). The J774.

Effect of Sasa senanensis Rehder extract on NO and PGE2 production by activated mouse macrophage-like RAW264.7 cells.

Alkaline extract of Sasa senanensis Rehder (SE) has shown diverse biological activity. As an extension, whether SE affects the function of activated macrophages was investigated. SE inhibited the nitric oxide (NO) production by lipopolysaccharide (LPS)-activated mouse macrophage-like RAW264.

Cell death induced by nutritional starvation in mouse macrophage-like RAW264.7 cells.

Amino acid utilization of mouse macrophage-like RAW264.7 cells was investigated. During the logarithmic growth stage, RAW264.

Disruption of amino acid metabolism in human myelogenous leukemic cell lines destined to die after contact with metal plates.

Changes in amino acid metabolism during cell death of human myelogenous leukemic cell lines (HL-1, ML-1, KG-1) induced by contact with gold (Au), silver (Ag) or palladium (Pd) were investigated. All three leukemic cell lines consumed glutamine and serine at the highest rate (amounting to 50%-58% and 12%-16% of the total amino acid consumption, respectively). HL-60 cell growth was slightly stimulated by contact with any metal plate.

Rapid changes in amino acid and polyamine metabolism during copper-induced cell death of human gingival fibroblast.

There are very few studies on the interaction between dental alloys and oral tissues. The effect of direct contact with copper (Cu) on the cellular function of human gingival fibroblast (HGF) derived from the periodontal tissues was investigated. When HGF cells were inoculated onto a Cu plate, the viability of HGF cells immediately declined.

Effect of saliva, epigallocatechin gallate and hypoxia on Cu-induced oxidation and cytotoxicity.

We have previously reported that contact with copper (Cu) induced immediate cell death via an oxidation-involved mechanism in human promyelocytic leukemic HL-60 cells, whereas contact with other metals (Au, Ag, Pd) produced no discernible effect. In the present study, we investigated the conditions under which Cu-induced oxidative stress can be reduced. Contact with a Cu plate in the absence of cells enhanced the rate of consumption of cystine to the greatest extent, followed by that of methionine and histidine.

Biological impact of contact with metals on cells.

In order to investigate the in vivo effect of metals used in dentistry, we investigated the effect of direct contact with metal plates (20 x 20 x 0.5 mm3) made of gold (Au), silver (Ag), copper (Cu) or palladium (Pd) on human promyelocytic leukemic HL-60 cells grown in RPMI1640 medium supplemented with 10% fetal bovine serum. When 0.

Quantitative structure-cytotoxicity relationship analysis of coumarin and its derivatives by semiempirical molecular orbital method.

A semiempirical molecular orbital method (CAChe) was applied to delineate the relationship between cytotoxicity against the human squamous cell carcinoma line HSC-2 (evaluated by 50% cytotoxic concentration, CC50) of 20 coumarin (2H-pyran-2-one) derivatives and twelve physical parameters (descriptors) calculated by the CONFLEX/PM3 method. There was a highly significant correlation between the CC50 and ionization potential, highest occupied molecular orbital (HOMO) energy, difference between electron energy of HOMO and electron energy of lowest unoccupied molecular orbital (LUMO), or absolute hardness (r2=0.756 - 0.

Interfacial behavior of fatty-acylated sericin prepared by lipase-catalyzed solid-phase synthesis.

Fatty-acylated sericin {1:0.7 molar ratio of sericin (Mr 18,700) to oleic acid} was prepared by lipase-catalyzed solid-phase synthesis in n-hexane containing oleic acid to endow sericin with interfacial properties. Acylation with oleic acid was confirmed by 1H-NMR.

Thermal behavior of fowl feather keratin.

Differential scanning calorimetry (DSC) was applied to elucidate the thermal behavior of fowl feather keratins (barbs, rachis, and calamus) with different morphological features. The DSC curves exhibited a clear and relatively large endothermic peak at about 110-160 degrees C in the wet condition. A considerable decrease in transition temperature with urea and its helical structure content estimated by Fourier transform infrared spectroscopy (FT-IR), and the disappearance of one of the diffraction peaks with heating at 160 degrees C for 30 min, indicated that DSC could be used to evaluate the thermal behavior of keratin.

Effect of endodontic agents on cytotoxicity induction by sodium fluoride.

We investigated six endodontic agents for their ability to induce apoptosis and modify the cytotoxic activity of NaF against human squamous cell carcinoma (HSC-2) and human promyelocytic leukemia (HL-60) cell lines. Four Group I agents (Form Cresol, Cam Phenic, Eucaly Soft, GC Fuji Varnish), but not two Group II agents (Caviton, Canals-N), induced internucleosomal DNA fragmentation and activated caspases 3, 8 and 9 in HL-60 cells. Only Cam Phenic among these agents additively enhanced the cytotoxic activity of NaF in HSC-2 and HL-60 cells.

Effect of antioxidants, oxidants, metals and saliva on cytotoxicity induction by sodium fluoride.

We have recently found that millimolar concentrations of sodium fluoride (NaF) induced apoptotic cell death, characterized by caspase activation and DNA fragmentation, in tumor cell lines. This finding paved the way to investigating the interaction between NaF and the oral environment. As an initial step, we investigated redox compounds, metals and saliva, which may modify the cytotoxic activity of NaF against a human oral squamous cell carcinoma cell line (HSC-2).

Effect of poly-herbal formula on NO production by LPS-stimulated mouse macrophage-like cells.

Pretreatment of mice with lyophilized hot water extracts of five poly-herbal formula protected them from lethal infection by E. coli. ESR spectroscopy shows that these extracts produced radicals under alkaline condition, and scavenged radicals such as superoxide anion, hydroxyl radical and nitric oxide (NO) radical.

Effect of lignins and their precursors on nitric oxide, citrulline and asparagine production by mouse macrophage-like Raw 264.7 cells.

Lignins, tannins and flavonoids are commonly found polyphenols. Among these polyphenols, lignins, polymers of phenylpropenoids complexed with polysaccharides, were the least cytotoxic and most potently stimulated the production of nitric oxide (NO), citrulline and asparagine by mouse macrophage-like Raw 264.7 cells.

Effects of isoflavones from Sophora species on the growth and activation of a mouse macrophage-like cell line.

We investigated the effect of eleven isoflavones on the growth and activation of mouse macrophage-like Raw 264.7 cells. The study of structure-activity relationship suggests that both hydrophilic (hydroxyl) and hydrophobic (prenyl) groups within isoflavone molecules are the determinants for the induction of cytotoxic activity.

Effects of prenylflavanones from Sophora species on growth and activation of mouse macrophage-like cell line.

We investigated the effect of 2 flavanones and 8 chemically-defined prenylflavanones on the growth and activation of mouse macrophage-like Raw 264.7 cells. Amino acid analysis in the culture medium demonstrated the rapid consumption of serine and glutamine by Raw264.

Stimulation of arginine consumption and asparagine production in LPS-activated macrophages.

Changes in amino acid utilization during lipopolysaccharide (LPS)-induced activation of mouse macrophage-like cells Raw264.7 were investigated. Amino acids in the medium and cell fractions were extracted by 5% trichloroacetic acid and quantitated by amino acid analyzer.