Surface Properties of Resin Composites and CAD/CAM Blocks After Simulated Toothbrushing.

OBJECTIVES: This study aimed to evaluate the surface gloss, surface roughness, and color change of restorative materials after a three-body wear abrasion. METHODS AND MATERIALS: Four resin composites with different filler particle size (Gracefil Flo [GFF, 0.7 µm], Gracefil LoFlo [GFL, 0.25 µm], Gracefil ZeroFlo [GFZ, 0.15 µm], and Gracefil Putty [GFP, 0.3 µm]), two CAD/CAM resin composite blocks with different filler particle size (Cerasmart 300 [CS3, 0.7 µm] and Cerasmart Prime [CSP, 0.3 µm], GC), and one CAD/CAM lithium disilicate glass-ceramic block (Initial LiSi Block [ILS], GC) as a control were evaluated. Twenty slab-shaped specimens were obtained from each material. Ten specimens were subjected to 80,000 toothbrushing strokes and measured for surface gloss (Gloss Unit, GU), surface roughness (Ra, µm), and color (L*, a*, and b* values) before toothbrushing and at every 20,000 strokes. Color differences (ΔL*, Δa*, Δb*, and ΔE00) before and after toothbrushing were calculated. After 80,000 strokes, abraded surfaces were observed using scanning electron microscopy. The other 10 specimens were measured for Vickers microhardness (VHN). RESULTS: After 80,000 toothbrushing strokes, the mean GU ranged from 60.43 to 16.12 (the highest for ILS and lowest for GFL), and the mean Ra ranged from 0.079 to 4.085 (the lowest for ILS and highest for GFL). At all measuring stages, the calculated ΔE00 values ranged from 0.31 to 0.92 for all materials. The mean VHN ranged from 632.34 to 39.08 (the highest for ILS and lowest for GFZ). The resin composite containing the largest filler particle (GFF) showed significantly lower Ra and higher VHN than other resin composites (GFL, GFZ, and GFP). The CAD/CAM resin composite block containing a smaller filler particle (CSP) retained significantly higher GU than that containing a larger filler particle (CS3). A negative correlation between GU and Ra was detected. CONCLUSIONS: Based on the findings, toothbrush abrasion induced a decrease in GU and an increase in Ra for all resin-based materials tested. Resin-based materials with larger filler size tended to show lower Ra, while resin-based materials with smaller filler size tended to show a smaller reduction in GU. These were more pronounced for light-cure resin composites than for resin composite blocks for CAD/CAM.

Clinical and Histological Study on Direct Pulp Capping With CO2 Laser Irradiation in Human Teeth.

The study aimed to histologically evaluate wound healing of exposed human pulp on direct pulp capping using super-pulsed CO2 laser preirradiation. In this single-blind clinical trial, 28 third molar teeth of 17 volunteers were randomly capped with either CO2 laser irradiation (n=14) or Dycal (calcium hydroxide cement; n=14) and restored using resin composite. The laser was operated in super-pulsed mode (pulse duration, 0.2 ms; interval, 5.8 ms; 0.003 J/pulse). The irradiation conditions were a power output of 0.5 W, an irradiation time of 15 seconds, repeat mode (10-ms irradiation and 10-ms intervals, for a total beam exposure time of 7.5 seconds), total applied energy of 3.75 J, and an activated air-cooling system. Each tooth was extracted at six or 12 months posttreatment and prepared for histological evaluation. We evaluated the parameters of pulp tissue disorganization, inflammatory cell infiltration, reparative dentin formation (RDF), and bacterial penetration. There were no significant differences between groups for all parameters at each postoperative period (Mann-Whitney U-test, p>0.05). CO2 laser irradiation completely controlled bleeding and exudate from the exposed pulp. The CO2 laser group had a tendency to delay RDF compared with the Dycal group, but 4 of 7 teeth from the CO2 laser group showed a complete dentin bridge at 12 months posttreatment.

A Review of hormone-based therapies to treat adult acne vulgaris in women.

Hormone-based therapies including combined oral contraceptive medications and spironolactone are considered effective therapies to treat adult acne in women. Our objective is to provide a concise and comprehensive overview of the types of hormonal therapy that are available to treat acne and comment on their efficacy and safety profiles for clinical practice. A systematic search using the PubMed Database was conducted to yield 36 relevant studies for inclusion in the review and several conclusions were drawn from the literature. Treatment with oral contraceptive pills leads to significant reductions in lesion counts across all lesion types compared with placebo. There were no consistent differences in efficacy between the different combined oral contraceptive formulations. In terms of risk, oral contraceptive pill users had three-times increased odds of venous thromboembolism versus non-users according to a recent meta-analysis (95% confidence interval 2.46-2.59). Data on oral contraceptive pill use and breast cancer risk are conflicting but individual patient risk factors and histories should be discussed and considered when prescribing these medications. However, use of these medications does confer measurable protection from endometrial and ovarian cancer. Spironolactone was also shown to be an effective alternative treatment with good tolerability. Combined oral contraceptive medications and spironolactone as adjuvant and monotherapies are safe and effective to treat women with adult acne. However, appropriate clinical examinations, screening, and individual risk assessments particularly for venous thromboembolism risk must be conducted prior to initiating therapy.

Association of ethnicity, Fitzpatrick skin type, and hirsutism: A retrospective cross-sectional study of women with polycystic ovarian syndrome.

BACKGROUND: The complex interplay between ethnicity, Fitzpatrick skin type (FST), and hirsutism in patients with polycystic ovarian syndrome (PCOS) is poorly understood. OBJECTIVE: In this cross-sectional, retrospective analysis, we examined the prevalence, severity, and distribution of hirsutism with clinician-rated site-specific and total modified Ferriman-Gallwey (mFG) visual scoring in a diverse cohort of American patients with PCOS. METHODS: Independent analyses were conducted on the basis of patient-reported FST ratings and ethnicity. RESULTS: In this PCOS cohort, a correlation was found between hirsutism and ethnicity and the highest prevalence of hirsutism and total mFG scores was observed in Hispanic, Middle Eastern, African American, and South Asian patients. A positive correlation between hirsutism and FST was also observed with an increasing prevalence of hirsutism in the group of patients with higher FSTs. Significant trends in the anatomic distribution of hirsutism were observed between ethnic groups as well. A higher facial mFG score was found in African American patients but higher mFG scores in the truncal and extremity regions were observed in Middle Eastern patients. Truncal hirsutism was also associated with higher FSTs. CONCLUSIONS: Ethnicity and FST may be important variables in both the quantitative and qualitative presentations of hirsutism in women with PCOS and should be considered in the diagnostic evaluation of any patient who is suspected of having the condition. Previously published studies that examined ethnicity, FST, and hirsutism in homogeneous cohorts limited comparison and generalizability but the strength of this study lies in its detailed analysis within a single large and diverse PCOS cohort. Validated studies are needed to determine whether clinical criteria for hirsutism should be adjusted for ethnicity and FST in the PCOS population and particularly within diverse cohorts and patients of mixed ancestry.

Factor from rat liver with antiinvasive potential on rat ascites hepatoma cells.

An acid/ethanol extract of normal rat liver, both in vitro and in vivo, inhibited the invasion by a highly invasive subpopulation of rat ascites hepatoma cells, AH 130 (LC-AH cells). The addition of 10-80 micrograms/ml extract inhibited the formation of penetrated colonies of LC-AH cells underneath the cultured mesothelial cell (M-cell) monolayer. The tumor cells pretreated with the extract showed the diminished colony formation. Preincubation of the extract with plasma membranes prepared from LC-AH cells abolished the effect of the extract, suggesting a binding of the inhibitory entity [tentatively termed as "invasion-inhibiting factor" (IIF)] to the tumor cell surface. The extract did not inhibit the growth of LC-AH cells, but suppressed their directed migration underneath the M-cell monolayer. A concomitant i.p. injection of the extract with LC-AH cells into rats prevented the invasion by tumor cells of the peritoneum and formation of tumor nodules in the peritoneum and mediastinum, indicating that IIF inhibited the tumor cell invasion and metastasis in vivo, as well. Upon ultrafiltration and gel fractionation, about 60% of IIF activity was recovered in the fraction corresponding to the molecular weight in the range of Mr 3000-4000. This activity was heat-stable at 100 degrees C at neutral pH but labile at acidic pH and was inactivated by the treatment with pronase. The rest of the activity of IIF was found in the fraction of more than Mr 25,000.

Potentiation of invasive capacity of rat ascites hepatoma cells by adriamycin.

The effect of Adriamycin on the invasive capacity of rat ascites hepatoma cells, W1, was studied. The invasive capacity of W1 cells was estimated in vitro by counting the number of penetrated single tumor cells and tumor cell colonies formed from the penetrated cells underneath a cultured mesothelial cell monolayer (H. Akedo et al., Cancer Res., 46: 2416-2422, 1986). A considerable increment of the invasive capacity was observed when the tumor cells had been treated with 1.0 to 20.0 microM Adriamycin. This augmentation of invasive capacity of tumor cells was partially inhibited by 60 microM N-acetylcysteine, a scavenger of free radicals. On the other hand, 60 microM N-acetylcysteine did not impair the cytotoxicity of Adriamycin for W1 cells measured by an in vitro tetrazolium-based colorimetric assay for cytotoxicity.

Macrophage potentiation of invasive capacity of rat ascites hepatoma cells.

In vitro and in vivo invasive capacities of rat ascites hepatoma cells (AH 130) that had been cultured on the feeder layers of rat macrophages were examined. The in vitro invasive capacity of the tumor cells was measured by their ability to form tumor cell colonies underneath cultured mesothelial cell monolayers; in vivo invasive capacity was examined by the implantation of the tumor cells into the rat peritoneal cavity. When the tumor cells were precultured on a macrophage feeder layer, the in vitro invasive capacity of the tumor cells increased almost 10 times as much as that of uncocultred control cells. The cocultured tumor cells, when implanted in rat peritoneal cavity, infiltrated extensively in the peritoneum and formed many tumor nodules and enlarged metastatic lymph nodes. Implantation of the uncocultured tumor cells did not develop any macroscopically detectable nodules. The effect of macrophages was reversed by subculturing the cocultured tumor cells without macrophages. Treatment of the tumor cells with the medium conditioned by macrophage culture did not result in the increase in invasive capacity. Almost 50% of the macrophage-mediated enhancement of the in vitro invasive capacity was inhibited by the simultaneous addition of superoxide dismutase and catalase at the time of tumor cell-macrophage coculture.

Interaction of rat ascites hepatoma cells with cultured mesothelial cell layers: a model for tumor invasion.

Interactions of rat ascites hepatoma cells with primary cultured layers of rat mesentery-derived cells were studied. The mesentery-derived cells were isolated from rat mesentery and cultured in Eagle's minimum essential medium with a 2-fold concentration of amino acids and vitamins supplemented with 10% calf serum. The primary cultured cells, consisting mainly of mesothelial cells in polygonal shape, forms a "paving stone" sheet. Upon seeding the tumor cells on the mesentery-derived cell layers, three different types of tumor cell growth were observed. Type 1 was the formation of piled-up tumor cell nests on mesothelial cell layers. Type 2 was the formation of flattened tumor cell islands underneath mesothelial cell layers. This island formation was clearly observed under a phase contrast microscope 2 days after the tumor cell seeding. Protrusion of cellular processes of the tumor cells beneath mesothelial cells was occasionally seen. Type 3 was the growth of tumor cells in suspension. These types of tumor cell growth closely resemble those in the peritoneal cavity observed after i.p. implantation of the tumor cells. When the tumor cells recovered from the blood of tumor-bearing rats were seeded, flattened tumor cell islands were formed 15 times more frequently than when the tumor cells isolated from host peritoneal cavity were seeded. Shortly after the appearance of small flattened tumor cell islands, a distinct morphological change of mesothelial cells from polygonal to spindle shape was seen preferentially at the marginal area of the cell layers (a partial retraction of cell edges). The retraction of mesothelial cells was induced not only by seeding the tumor cells but by adding the tumor ascites fluid or the medium conditioned by the tumor cell culture. The morphological change was reversed by changing the culture medium to remove the effectors. These results indicate that the system described in this study can provide a useful model to study tumor cell invasion.

Putrescine-dependent invasive capacity of rat ascites hepatoma cells.

The effects of inhibitors of polyamine synthesis on the invasive capacity of rat ascites hepatoma (LC-AH) cells were examined by in vitro assay of penetration of the LC-AH cells through a monolayer of calf pulmonary arterial endothelial (CPAE) cells. Pretreatment of LC-AH cells with alpha-difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase, before seeding them onto a CPAE cell monolayer and culturing them for 24 h in the absence of DFMO decreased the number of penetrating tumor cells time and dose dependently (about 35% of the maximal inhibition) without affecting their viability or proliferative activity. DFMO treatment caused a marked decrease in the intracellular level of putrescine but not of spermidine or spermine. The DFMO-induced decreases in invasive capacity and putrescine level were almost completely reversed by the addition of putrescine to the medium during pretreatment with DFMO or invasion assay but were not affected by exogenous spermidine or spermine. No change in the invasive capacity was observed when the CPAE cells were treated with DFMO and the LC-AH cells with methylglyoxal-bis(guanylhydrazone), an inhibitor of S-adenosylmethionine decarboxylase, which depressed the spermidine and spermine levels but increased the putrescine level in the LC-AH cells. These results suggest that intracellular putrescine modulates the in vitro invasive capacity of LC-AH cells.

Tumor invasion-inhibiting factor 2: primary structure and inhibitory effect on invasion in vitro and pulmonary metastasis of tumor cells.

The primary structure of tumor invasion-inhibiting factor 2 (IIF-2) purified from bovine liver (A. Isoai et al., Jpn. J. Cancer Res., 81:909-914, 1990) was determined. A computer homology search of the National Biomedical Research Foundation data bank revealed that IIF-2 is identical to the carboxyl-terminal region, residue number [69-89], of high mobility group 17 which is a DNA-binding non-histone protein. IIF-2 synthesized by an automated peptide synthesizer showed similar invasion-inhibitory activity as compared with the purified factor, when tested with the monolayer invasion assay system using highly invasive rat ascites tumor cells. When examined with the other in vitro assay systems using a modified Boyden chamber, the synthetic IIF-2 suppressed the chemotactic migration of highly metastatic B16 melanoma (B16FE7) cells to fibronectin or laminin and invasion through Matrigel. The IIF-2 inhibited neither the cell proliferation nor the binding of cells to fibronectin or Matrigel and also showed no significant inhibition of Mr 90,000 type IV collagenase (gelatinase) obtained from human schwannoma (YST-3) cells. The formation of lung colonies in mice given injections of B16FE7 and Lewis lung carcinoma cells was significantly reduced by the coinjection of the IIF-2. These results suggest that IIF-2 suppresses tumor invasion by impairing cell motility and inhibits the migration of metastasizing cells through extracellular matrix (extravasation steps) following their arrest in the capillary bed of the lung in vivo.

cis-9,cis-15-octadecadienoic acid: a novel fatty acid found in higher plants.

An unusual fatty acid, cis-9,cis-15-octadecadienoic acid, has been identified in the pulp lipids of mango (Mangifera indica L.) grown in the Philippines. To our knowledge, the occurrence of cis-9,cis-15-octadecadienoic acid in higher plant lipids has not been previously reported. The structure confirmation was based on the results of chromatographic (capillary GC, argentation thin-layer) and spectrometric (GC-MS, infrared, ultraviolet) analysis and chemical treatment. This butylene-interrupted dienoic fatty acid is concentrated in the pulp part of mango fruit and occupies 5.4% of total acyl groups in the pulp lipids; whereas a common octadecadienoic acid, linoleic acid, is a minor component (1.1%) in the same lipids. If a trivial name is desired, it is suggested that cis-9,cis-15-octadecadienoic acid be called "mangiferic" acid.

Cooperation of fibronectin with lysophosphatidic acid induces motility and transcellular migration of rat ascites hepatoma cells.

We have previously shown that the transcellular migration of rat ascites hepatoma (AH130-MM1) cells through a cultured mesothelial cell monolayer (MCL) is triggered with lysophosphatidic acid (LPA) that stimulates actin polymerization and myosin light chain phosphorylation through the activation of Rho-ROCK (Rho-kinase) cascade. When, however, the motility of MM1 cells on a glass surface was tested by phagokinetic track motility assay, LPA failed to induce the motility. Nevertheless, when the glass had been coated with fibronectin (FN), LPA could induce phagokinetic motility which was accompanied by transformation of MM1 cells to fusiform-shape and assembly of focal adhesion. beta1 integrin, the counter receptor of FN, was expressed on MM1 cells. Anti-FN antibody, anti-beta1 integrin antibody and cyclo-GRGDSPA remarkably suppressed LPA-induced phagokinetic motility. These antibodies suppressed LPA-induced transcellular migration through MCL, as well. These results indicate that actin polymerization and phosphorylation of myosin light chain through Rho activation are insufficient for inducing motility but the cooperative FN/beta1 integrin-mediated adhesion is necessary for both the phagokinetic motility and transcellular migration of MM1 cells.

Correlation of alkaline phosphatase activity with cell population density in tissue culture cells originated from rat liver.

Alkaline phosphatase (ALP) activity of cultured Li-10 cells obtained from rat liver was found to be a function of cell population density. After the cells grew to confluence, the enzyme activity per cell increased about 100 times that at a low population density. The increase of activity was inhibited by the addition of actinomycin D or cycloheximide to the culture medium. When the cells that had gained high ALP activity after confluency were subcultured, ALP activity decreased to a low basal level after about 48 h. Under cytochemical examination using an electron microscope, the induced ALP activity was seen exclusively at the apical surface region of the cells but scarcely at cell-cell and cell-substratum contact regions.

Participation of rhop21 in serum-dependent invasion by rat ascites hepatoma cells.

Rat ascites hepatoma cells (MM1 cells) penetrate through a cultured mesothelial cell monolayer (MCL) in the presence of fetal calf serum (FCS), but scarcely do so in its absence. Inactivation of rhop21 of MM1 cells by ADP-ribosyltransferase C3 resulted in the suppression of this serum effect on the penetration, suggesting that the serum effect was mediated by rhop21. To ascertain this assumption MM1 cells were transfected with an activated (Val14) human rhoA cDNA (Neo/RhoA 1-7). The transfectants penetrated MCL extensively even in the absence of FCS and became largely independent of serum for the penetration. These results suggest that serum-induced invasion by MM1 cells is mainly mediated by rhop21.

Involvement of small GTPases Rho and Rac in the invasion of rat ascites hepatoma cells.

Lysophosphatidic acid (LPA) triggers the invasion of a mesothelial cell monolayer by rat ascites hepatoma (MM1) cells. LPA also induces rapid morphological changes of MM1 cells, cell surface blebbing and pseudopodia formation. Pseudopodia formation is tightly correlated with cellular invasiveness. Clostridium Botulinum C3 exoenzyme and genistein abrogated the formation of blebs and pseudopodia together with the inhibition of invasion, indicating that GTPase Rho and certain tyrosine kinases are involved in both processes. MM1 cells expressing constitutively active Rho exhibited the invasion and the formation of blebs and pseudopodia in the absence of LPA. In contrast, MM1 cells expressing constitutively active Rac were not invasive in the absence of LPA, but were invasive in the presence of LPA. Their morphological response to LPA was almost the same as that of parental MM1 cells. Expression of dominant negative Rac suppressed the invasiveness to approximately 3% of that of parental MM1 cells, together with the inhibition of pseudopodia formation. Thus, Rho and Rac are cooperatively involved in both the invasion and the related morphological changes of MM1 cells. Rho activation is sufficient both for the induction of invasion and the morphological changes leading to the invasion, whereas Rac activation is necessary but not sufficient by itself. We propose that Rho activation is not mediated by Rac but the cooperation of both GTPases is essential to trigger the invasive behavior of MM1 cells.

Inhibition by ginsenoside Rg3 of bombesin-enhanced peritoneal metastasis of intestinal adenocarcinomas induced by azoxymethane in Wistar rats.

The effects of concomitant use of bombesin and ginsenoside Rg3 on the incidence of peritoneal metastasis of intestinal adenocarcinomas induced by azoxymethane were investigated in male inbred Wistar rats. From the start of the experiment, rats were given weekly s.c. injections of azoxymethane (7.4 mg/kg body weight) for 10 weeks and s.c. injection of bombesin (40 microg/kg body weight) every other day, and from week 20, s.c. injections of ginsenoside Rg3 (2.5 or 5.0 mg/kg body weight) every other day until the end of the experiment in week 45. Bombesin significantly increased the incidence of intestinal tumors and cancer metastasis to the peritoneum in week 45. It also significantly increased the labeling index of intestinal cancers. Although administration of a higher dose of ginsenoside Rg3 with bombesin had little or no effect on the enhancement of intestinal carcinogenesis by bombesin, the location, histologic type, depth of involvement, infiltrating growth pattern, labeling and apoptotic indices and tumor vascularity of intestinal cancers, it significantly decreased the incidence of cancer metastasis. These findings indicate that ginsenoside Rg3 inhibits cancer metastasis through activities that do not affect the growth or vascularity of intestinal cancers.

Down-regulation of focal adhesion kinase, pp125FAK, in endothelial cell retraction during tumor cell invasion.

Although endothelial cell retraction is required before tumor cell invasion, its molecular mechanism still remains obscure. We previously demonstrated that conditioned medium (CM) derived from a human pancreatic cancer cell line, PSN-1, induced endothelial cell retraction and facilitated tumor cell invasion. To investigate the molecular change of events in the transduction of extracellular signals during endothelial cell retraction, we examined the effect of the CM derived from PSN-1 cells on the tyrosine phosphorylation in endothelial cells. Immunoblot analyses revealed that the PSN-1 CM decreased tyrosine phosphorylation of a 120-130 kD protein, and induced the concomitant down-regulation of focal adhesion kinase, pp125FAK, during endothelial cell retraction in time- and dose-dependent fashions. These changes preceded endothelial cell retraction and were reversible after removal of the CM. Further quantitative densitometric analyses demonstrated that the extent of decrease in tyrosine phosphorylated 120-130 kD protein during the endothelial cell retraction was likely to be proportional to that of the down-regulation of pp125FAK. A tyrosine phosphorylated 120-130 kD protein immunoprecipitated by anti-phosphotyrosine antibody immunoreacted with anti-pp125FAK antibody. These results suggested that decreased amount of a tyrosine phosphorylated 120-130 kD protein probably due to the down-regulation of pp125FAK might be associated with the signal transduction pathway in the endothelial cells during their retraction. Furthermore, these findings were also observed in the CM from another four human cancer cell lines, suggesting the down-regulation of pp125FAK in endothelial cells during tumor cell invasion.