Myocardial injury after orbital atherectomy and its association with coronary lesion length.

BACKGROUND: Limited data are available regarding myocardial injury and its risk factors in percutaneous coronary interventions (PCI) of severe calcified lesions using orbital atherectomy (OA). METHODS: Patients who underwent OA at our institution were retrospectively enrolled into the present registry. High-sensitive Troponin I (hsTroponin I), EKG and echocardiography were used to assess myocardial injury after the procedure. RESULTS: A total of 27 patients between who underwent OA between January 2022 and June 2023 were included. Myocardial injury (elevation of hsTroponin I above the 99th percentile upper reference limit) occurred in all patients. Median hsTroponin I on the first day after the procedure was 1093 (557-4037) ng/l with a minimum of 86 ng/l and a maximum of 25,756 ng/l. Myocardial infarction occurred in two patients (7 %), who had severe coronary dissection after OA. Lesions were longer (47 [38-52] mm vs. 20 [14-47] mm; p = 0.009) in patients with hsTroponin I levels above the median compared to those with levels below. Furthermore, a moderate correlation between hsTroponin I and lesion length was detected (r = 0.54; p = 0.004). CONCLUSIONS: In the present study myocardial injury occurred in all patients after OA without loss of viable myocardium in the majority of patients. Lesions length was found to be a significant factor associated with markedly increased hsTroponin I after the OA procedure.

NAC ameliorates dental composite-induced DNA double-strand breaks and chromatin condensation.

Released (co)monomers from dental composite components can induce DNA damage of which DNA double-strand breaks (DSBs) threaten genome integrity. Here, we tested whether the administration of the antioxidant N-acetylcysteine (NAC) is able to reduce the dental composite-induced DSBs in primary human gingiva fibroblasts. The dental composites Bis-GMA (bisphenol-A-glycerolate dimethacrylate), GMA (glycidyl methacrylate), HEMA (2-hydroxyethyl methacrylate) and TEGDMA (triethyleneglycol dimethacrylate) were found to induce co-localizing microscopic nuclear foci numbers of the DSB markers γ-H2AX and 53BP1 per cell in the order: GMA>Bis-GMA>TEGDMA>HEMA. Supplementation of (co)monomer-containing culture medium with NAC led to a significant reduction of resin-induced DSBs as well as to an amelioration of dental monomer-induced nuclear chromatin condensation in gingival fibroblasts. Thus, antioxidant treatment can reduce radical-induced chromatin and DNA damage and open avenues to mitigate genotoxic effects of dental composite compounds.

Effect of layer thickness on the elution of bulk-fill composite components.

OBJECTIVE: An increment layering technique in a thickness of 2mm or less has been the standard to sufficiently convert (co)monomers. Bulk fill resin composites were developed to accelerate the restoration process by enabling up to 4mm thick increments to be cured in a single step. The aim of the present study is to investigate the effect of layer thickness on the elution of components from bulk fill composites. METHODS: The composites ELS Bulk fill, SDR Bulk fill and Venus Bulkfill were polymerized according to the instruction of the manufacturers. For each composite three groups with four samples each (n=4) were prepared: (1) samples with a layer thickness of 2mm; (2) samples with a layer thickness of 4mm and (3) samples with a layer thickness of 6mm. The samples were eluted in methanol and water for 24h and 7 d. The eluates were analyzed by gas chromatography/mass spectrometry (GC/MS). RESULTS: A total of 11 different elutable substances have been identified from the investigated composites. Following methacrylates showed an increase of elution at a higher layer thickness: TEGDMA (SDR Bulk fill, Venus Bulk fill), EGDMA (Venus Bulk fill). There was no significant difference in the elution of HEMA regarding the layer thickness. The highest concentration of TEGDMA was 146µg/mL for SDR Bulk fill at a layer thickness of 6mm after 7 d in water. The highest HEMA concentration measured at 108µg/mL was detected in the methanol eluate of Venus Bulk fill after 7 d with a layer thickness of 6mm. SIGNIFICANCE: A layer thickness of 4mm or more can lead to an increased elution of some bulk fill components, compared to the elution at a layer thickness of 2mm.

A case report of the new Polyzene™-F COBRA PzF™ Nanocoated Coronary Stent System (NCS): Addressing an unmet clinical need.

Because of anticipated antiplatelet medication risks, patients who are not DES candidates or who are at particularly high risk for bleeding events have been targeted initially for treatment with the COBRA PzF Coronary Stent System. We report the case of a successful experience with a new, Polyzene™-F COBRA PzF™ Coronary Stent System, designed to impart thrombo-resistance and reduce inflammation, to achieve shorter dual antiplatelet therapy duration while reducing restenosis incidence in a high risk patient with atrial fibrillation.

Dental composite components induce DNA-damage and altered nuclear morphology in gingiva fibroblasts.

OBJECTIVE: Released dental composite components can damage human gingival fibroblasts (HGFs) and their DNA. The cytotoxicity, chromatin condensation and the induction of DNA double strand breaks (DSBs) by different compounds of dental composites was investigated using an improved γ-H2AX focus assay. METHODS: HGFs were incubated with the monomers: bisphenol-A-ethoxylate-dimethacrylate (Bis-DMA), bisphenol-A-glycerolate-dimethacrylate (BisGMA), ethyltriethylen glycol methacrylate (ETEGMA), glycidyl methacrylate (GMA), 1,6-hexandiol-dimethycrylate (HDDMA), trimethylolpropane ethoxylate triacrylate (TMPTA), and acrylamide (ACR). DSBs were determined by enumerating γ-H2AX and 53BP1 foci colocalized at DSBs. RESULTS: A concentration-dependent induction of DSBs was found in the order: GMA>BisGMA>ACR>Bis-DMA>HDDMA>TMPTA>ETEGMA. HGFs exposure to GMA (0.3mM) and to BisGMA (0.09mM) induced the highest rate of DSB foci, i.e. 12-fold and 8-fold, respectively, relative to control (0.33 DSB foci/cell). At the highest concentrations (EC50) prominent changes in the chromatin morphology of HGF cell nuclei, i.e. compaction of nuclear chromatin and reduction of the area covered by the ovoid fibroblast nuclei, were observed. Nuclear condensation was significantly induced by GMA (1.7-fold at 0.3mM) and BisGMA (1.6-fold at 0.09mM), which correlated with the highest numbers of induced DSB foci (GMA, BisGMA, 3.9 and 2.6 foci/cell, respectively). SIGNIFICANCE: The improved γ-H2AX/53BP1 focus assay revealed a concentration-dependent increase in DSBs for all tested substances. Furthermore, concentration-dependent changes in HGF cell nucleus morphology was noted, demonstrating genotoxic effects of the substances tested.

Cytotoxicity and induction of DNA double-strand breaks by components leached from dental composites in primary human gingival fibroblasts.

INTRODUCTION: The public interest steadily increases in the biological adverse effects caused by components released from resin-based dental restorations. OBJECTIVE: In this study, the cytotoxicity and the genotoxicity were investigated of following released components from dental resin restorations in human gingival fibroblasts (HGF): tetraethyleneglycol dimethacrylate (TEEGDMA), neopentylglycol dimethacrylate (Neopen), diphenyliodoniumchloride (DPIC), triphenyl-stibane (TPSB) and triphenylphosphane (TPP). METHODS: XTT based cell viability assay was used for cytotoxicity screening of substances. γ-H2AX assay was used for genotoxicity screening. In the γ-H2AX assay, HGFs were exposed to the substances for 6h. Induced foci represent double DNA strand breaks (DSBs), which can induce ATM-dependent phosphorylation of the histone H2AX. Cell death effects (apoptosis and necrosis), induced by the substances were visually tested by the same investigator using the fluorescent microscope. RESULTS: All tested substances induced a dose-dependent loss of viability in HGFs. Following toxicity ranking among the substances at EC50-concentration were found in the XTT assay (mM, mean±SEM; n=5): DPIC>Neopen>TPSB>TPP>TEEGDMA. DSB-foci per HGF-cell were obtained, when HGFs were exposed to the EC50-concentration of each substance in the following order (mean±SEM; n=3): DPIC>Neopen>TPSB>TPP>TEEGDMA. Multi-foci cells (cells that contain more than 40 foci each) in 80 HGF-cells at EC50-concentration of each substance were found as follow (mean±SEM; n=3): DPIC>Neopen>TPP>TPSB>TEEGDMA. Cell apoptosis contained in each substance at EC50-concentration in the following order (mean±SEM; n=3): DPIC>Neopen>TPSB>TPP >TEEGDMA. Cell necrosis contained in each substance at EC50-concentration in the following order (mean±SEM; n=3): DPIC>Neopen>TPSB>TPP>TEEGDMA. CONCLUSION: Leached components from dental resin restorations can induce DNA DSBs and cell death effects in HGFs.