Considerations on determining the castability of dental casting alloys

Castability is, along with biocompatibility, one of the most important characteristics of metallic materials used for dental prosthetic applications. In addition, the characteristics and performance of the employed casting machine are also decisive for the end result of the casting, especially when dealing with titanium or a titanium alloy. Starting from a critical analysis of the existing methods for determining the castability of dental alloys, the current paper presents a new method (and associated pattern) for determining the castability. Also, given the castability’s dependence on the type of casting machine, the paper includes an analysis of suitable casting machines and suggests some possible improvements

Analysis of the evolution of pollution indicators in a crossroads area of Sibiu, Romania

Starting from a new study on carbon monoxide and noise pollution levels in an important crossroads area of the city of Sibiu, Romania, the current paper uses the data to compare with data obtained during past studies carried out on the same area, allowing an assessment of the evolution of the two pollution indicators over time. The recent study, carried out over a two-week period in November 2017 both during the peak morning hours and at midday, combined a video-based vehicle count with measurements of the carbon monoxide and of the noise level, respectively. The data comparison reveals not only a worsening of the pollution levels in the centre of Sibiu over the past few years and should allow the determining of the best methods and means for reducing the level of the pollutants, possibly in correlation with the improvement of the road traffic conditions

Considerations on determining the castability of dental casting alloys

Castability is, along with biocompatibility, one of the most important characteristics of metallic materials used for dental prosthetic applications. In addition, the characteristics and performance of the employed casting machine are also decisive for the end result of the casting, especially when dealing with titanium or a titanium alloy. Starting from a critical analysis of the existing methods for determining the castability of dental alloys, the current paper presents a new method (and associated pattern) for determining the castability. Also, given the castability’s dependence on the type of casting machine, the paper includes an analysis of suitable casting machines and suggests some possible improvements

Combined regimen of photodynamic therapy mediated by Gallium phthalocyanine chloride and Metformin enhances anti-melanoma efficacy.

BACKGROUND:Melanoma therapy is challenging, especially in advanced cases, due to multiple developed tumor defense mechanisms. Photodynamic therapy (PDT) might represent an adjuvant treatment, because of its bimodal action: tumor destruction and immune system awakening. In this study, a combination of PDT mediated by a metal substituted phthalocyanine-Gallium phthalocyanine chloride (GaPc) and Metformin was used against melanoma. The study aimed to: (1) find the anti-melanoma efficacy of GaPc-PDT, (2) assess possible beneficial effects of Metformin addition to PDT, (3) uncover some of the mechanisms underlining cell killing and anti-angiogenic effects. METHODS:Two human lightly pigmented melanoma cell lines: WM35 and M1/15 subjected to previous Metformin exposure were treated by GaPc-PDT. Cell viability, death mechanism, cytoskeleton alterations, oxidative damage, were assessed by means of colorimetry, flowcytometry, confocal microscopy, spectrophotometry, ELISA, Western Blotting. RESULTS:GaPc proved an efficient photosensitizer. Metformin addition enhanced cell killing by mechanisms dependent on the cell line, namely apoptosis in the metastatic M1/15 and necrosis in the radial growth phase, WM35. Cell death mechanism relied on the inhibition of nuclear transcription factor (NF)-κB activation and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) sensitization, leading to TRAIL and TNF-α induced apoptosis. Metformin diminished the anti-angiogenic effect of PDT. CONCLUSIONS:Metformin addition to GaPc-PDT increased tumor cell killing through enhanced oxidative damage and induction of proapoptotic mechanisms, but altered PDT anti-angiogenic effects. GENERAL SIGNIFICANCE:Combination of Metformin and PDT might represent a solution to enhance the efficacy, leading to a potential adjuvant role of PDT in melanoma therapy

Melanogenesis.

<p>Total melanin content (μg/ml) and tyrosinase enzymatic activity (Units/mg protein) measurements in WM35 (upper panels) and M1-15 (lower panels) were done by spectrophotometry. Each bar represents mean ± standard deviation (n = 3). ir = irradiated cells; # = not significant, * = p<5.0E-02, ** = p<1.0E-02, *** = p<1.0E-03.</p

Oxidative stress assessment.

<p>Malondyaldehide (MDA), nitric oxide (NO) levels (nM/mg protein) measurements in WM35 (upper panels) and M1-15 (lower panels) were done by spectrophotometry. Each bar represents mean ± standard deviation (n = 3). ir = irradiated cells; # = not significant, * = p<5.0E-02, ** = p<1.0E-02, *** = p<1.0E-03.</p

Protein expression measured by Western Blot.

<p>Protein expressions of NF-κB, pNF-kB, IκKα, IκKβ, pIκK α/β, HIF1α, tyrosinase and MITF in melanoma cells treated with GaPc-PDT + Metformin, left panel (WM35), right panel (M1-15) were measured by WB. Image analysis of WB bands was done by densitometry, results were normalised to GAPDH.—WB images (upper panels) 1 = control, 2 = irradiated control, 3 = Metformin, 4 = irradiated Metformin, 5 = GaPc, 6 = GaPc-PDT, 7 = GaPc and Metformin, 8 = GaPc-PDT and Metformin; graphical representation of quantitative WB results for WM35 and M1-15 (lower panels); ir = irradiated cells; # = not significant, * = p<5.0E-02, ** = p<1.0E-02, *** = p<1.0E-03. Each bar represents mean ± standard deviation (n = 3).</p

Assessment of inflamatory and angiogenetic markers.

<p>Protein expressions of TNF-α, TRAIL, VEGF (pg/ml) in melanoma cultures exposed to GaPc-PDT + Metformin were determined by ELISA, upper panels (WM35), lower panels (M1-15); Each bar represents mean ± standard deviation (n = 3), ir = irradiated cells; # = not significant, * = p<5.0E-02, ** = p<1.0E-02, *** = p<1.0E-03.</p

Viability testing after GaPc-PDT and Metformin exposure.

<p>WM35 (a, b), M1-15 (c, d) melanoma cell cultures exposed to GaPc-PDT (a, c), respectively GaPc-PDT+ Metformin (b, d). OD 540 graphs were generated using GraphPad Software and show mean values ± standard deviation, n = 3 for each sample. Cell viability of both cell lines was decreased by GaPc-PDT depending on GaPc concentration and irradiation dose; Metformin increased the efficacy of GaPc-PDT especially in WM35 cells. e-images of WM35 (upper panels) and M1-15 (lower panels) cells subjected to GaPc-PDT and Metformin. Cells exposed to GaPc w/o Metformin, showed a normal morphology, compared to controls, while PDT irradiation of treated cells induced loss of cell adhesion, pleiomorphysm with spherical or bipolar shaped cells, signs of treatment induced photo-toxicity.</p

Chemical formula.

<p>Chloro-gallium (III) phthalocyanine (a) and Metformin (b).</p