Evaluation of fracture strength and translucency of 3D printing resin crown for carious primary anterior tooth / 대한구강보건학회지

Objectives@#The purpose of this study was to compare the fracture strength and traslucency of 3D printing resin crowns according to different thicknesses. @*Methods@#Resin crowns were designed with CAD software and a 3D scanner, using scanned data of the #61 tooth model. Resin Crowns with different thicknesses were printed using a 3D printer, and subsequently divided into four groups according to thickness (0.3, 0.5, 0.7, and 1.0 mm). Fracture strength was compared among groups with a resin strip crown of 1.0 mm thickness. Compressive force was applied using a universal testing machine at 30° along the lingual surface at 1 mm/min cross head speed. For translucency evaluation, thin square specimens were printed of thicknesses 0.3, 0.5, 0.7, and 1.0 mm, and translucency was measured using a spectrophotometer. @*Results@#As a result of fracture strength measurement, fracture strength increased as thickness increased, and a significant difference was observed solely between thicknesses of 0.3 and 0.5 mm, and the thicknesses of 0.3 and 0.5 mm (P<0.05). Translucency decreased as thickness increased, and similarly, a significant difference was observed only between thicknesses of 0.3 and 0.5 mm and the thicknesses of 0.7 and 1.0 mm (P<0.05). @*Conclusions@#A 3D printing resin crown can be used as a clinical option for restoring a primary anterior tooth affected by caries.

Studies on inhibition of gingival fibroblast proliferation by nicotine concentration / 대한구강보건학회지

Objectives@#To investigate the effect of nicotine on the healing of an oral cavity wound, high and low concentrations of nicotine were administered on human gingival fibroblasts. @*Methods@#Nicotine at concentrations of 0.1, 1, 5, and 10 mM were administered to gingival fibroblasts to evaluate the survival capability of the cells. Nicotine at 0.1 mM, a nonapoptotic concentration, was administered to evaluate apoptosis using Annexin V-FITC/Propidium Iodide cell staining.Nicotine at 1, 10, and 100 mM were administered to measure the expression of inflammatory cytokines, which was measured by RT-PCR and ELISA. FGF was treated with an additional 1, 10, or 100 mM of nicotine to evaluate cell proliferation and wound healing. @*Results@#As the concentration of nicotine increased (0.1, 1, 5, and 10 mM), the survival capability of the cells reduced. When cells were exposed to low nicotine concentration (0.1 mM) for 24 h, apoptosis occurred. Moreover, if the cell was exposed for 48 h, cell apoptosis occurred with necrosis. As the concentration of nicotine increased (1, 10, and 100 mM), more inflammatory cytokines were expressed. When EC LPS and TF LPS were combined with a low concentration of nicotine (1 and 10 mM), the expression of inflammatory cytokines was suppressed. The FGF level decreased as the nicotine concentration increased (1, 10, and 100 mM). @*Conclusions@#Nicotine interferes with the wound healing process of gingival fibroblasts. To maintain the wound healing process after a surgery or dental procedure, cessation of smoking is recommended.

Studies on inhibition of gingival fibroblast proliferation by nicotine concentration / 대한구강보건학회지

Objectives@#To investigate the effect of nicotine on the healing of an oral cavity wound, high and low concentrations of nicotine were administered on human gingival fibroblasts. @*Methods@#Nicotine at concentrations of 0.1, 1, 5, and 10 mM were administered to gingival fibroblasts to evaluate the survival capability of the cells. Nicotine at 0.1 mM, a nonapoptotic concentration, was administered to evaluate apoptosis using Annexin V-FITC/Propidium Iodide cell staining.Nicotine at 1, 10, and 100 mM were administered to measure the expression of inflammatory cytokines, which was measured by RT-PCR and ELISA. FGF was treated with an additional 1, 10, or 100 mM of nicotine to evaluate cell proliferation and wound healing. @*Results@#As the concentration of nicotine increased (0.1, 1, 5, and 10 mM), the survival capability of the cells reduced. When cells were exposed to low nicotine concentration (0.1 mM) for 24 h, apoptosis occurred. Moreover, if the cell was exposed for 48 h, cell apoptosis occurred with necrosis. As the concentration of nicotine increased (1, 10, and 100 mM), more inflammatory cytokines were expressed. When EC LPS and TF LPS were combined with a low concentration of nicotine (1 and 10 mM), the expression of inflammatory cytokines was suppressed. The FGF level decreased as the nicotine concentration increased (1, 10, and 100 mM). @*Conclusions@#Nicotine interferes with the wound healing process of gingival fibroblasts. To maintain the wound healing process after a surgery or dental procedure, cessation of smoking is recommended.

Comparative Study of Esophageal Self-expandable Metallic Stent Insertion and Gastrostomy Feeding for Dysphagia Caused by Lung Cancer / 대한소화기학회지

BACKGROUND/AIMS: Dysphagia is encountered in a large proportion of patients with lung cancer and is associated with malnutrition and a poor quality of life. This study compared the clinical outcomes of self-expandable metallic stent (SEMS) insertion and percutaneous gastrostomy (PG) feeding for patients with lung cancer and dysphagia. METHODS: A total of 261 patients with lung cancer, who underwent either SEMS insertion (stent group) or PG (gastrostomy group) as an initial treatment procedure for dysphagia between July 1997 and July 2015 at the Samsung Medical Center, were reviewed retrospectively, and 84 patients with esophageal obstruction were identified. The clinical outcomes, including the overall survival, additional intervention, complications, and post-procedural nutritional status in the two groups, were compared. RESULTS: Among the 84 patients finally analyzed, 68 patients received SEMS insertion and 16 had PG. The stent group had less cervical obstruction and more mid-esophageal obstruction than the gastrostomy group. The Kaplan-Meier curves revealed similar overall survival in the two groups. Multivariate analysis showed that the two modalities had similar survival rates (PG compared with SEMS insertion, hazard ratio 0.682, p=0.219). Fifteen patients (22.1%) in the stent group received additional intervention, whereas there was no case in the gastrostomy group (p=0.063). The decrease in the serum albumin level after the procedure was lower in the gastrostomy group than in the stent group (-0.20±0.54 g/dL vs. -0.65±0.57 g/dL, p=0.013) CONCLUSIONS: SEMS insertion and PG feeding for relieving dysphagia by lung cancer had a comparable survival outcome. On the other hand, PG was associated with a better nutritional status.

Resveratrol Inhibits Hypoxia-Induced Vascular Endothelial Growth Factor Expression and Pathological Neovascularization

PURPOSE: To investigate the effects of resveratrol on the expression of hypoxia-inducible factor 1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) in human adult retinal pigment epithelial (ARPE-19) cells, and on experimental choroidal neovascularization (CNV) in mice. MATERIALS AND METHODS: ARPE-19 cells were treated with different concentrations of resveratrol and then incubated under hypoxic conditions with subsequent evaluation of cell viability, expression of HIF-1alpha, and expression of VEGF. The effects of resveratrol on the synthesis and degradation of hypoxia-induced HIF-1alpha were evaluated using inhibitors of the PI3K/Akt/mTOR and the ubiquitin proteasome pathways. In animal studies, CNV lesions were induced in C57BL/6 mice by laser photocoagulation. After 7 days of oral administration of resveratrol or vehicle, which began one day after CNV induction, image analysis was used to measure CNV areas on choroidal flat mounts stained with isolectin IB4. RESULTS: In ARPE-19 cells, resveratrol significantly inhibited HIF-1alpha and VEGF in a dose-dependent manner, by blocking the PI3K/Akt/mTOR signaling pathway and by promoting proteasomal HIF-1alpha degradation. In mice experiments, orally administered resveratrol significantly inhibited CNV growth in a dose-dependent manner. CONCLUSION: Resveratrol may have therapeutic value in the management of diseases involving pathological neovascularization.

Effect of Amiloride to Retinal Toxicity Induced by Tissue Plasminogen Activator

PURPOSE: The effects of amiloride on cellular toxicity caused by tissue plasminogen activator (tPA) in mouse primary retinal cells were investigated. METHODS: Primary retinal cell cultures were maintained using glial conditioned medium. Commercial tPA and L-arginine were added, and the level of cyclic guanosine monophosphate (cyclic-GMP) in the culture supernatant was assessed using an ELISA assay. We measured the cell viability of cultured retinal cells pretreated with three different concentrations of amiloride (1, 10, and 100 microm) in addition to commercial tPA or L-arginine treatment. RESULTS: After exposing the cultured mouse retinal cells to tPA plus L-arginine or L-arginine alone, cyclic-GMP concentrations were 61.9 +/- 5.1 pmole/mL and 63.1 +/- 6.1 pmole/mL, respectively. However, the control group had a significantly lower concentration of cyclic-GMP (37.2 +/- 3.4 pmole/mL, p < 0.01). The cyclic GMP-dissolved solution did not cause retinal cell death. In the control group and the group treated with 1 microm amiloride and tPA containing L-arginine, the cell viability was 43.7% and 44.5%, respectively. However, cell viability increased to 70.6% with 10 microm amiloride and 78.4% with 100 microm amiloride (p = 0.015). CONCLUSIONS: L-arginine increases intracellular cyclic-GMP and may give rise to retinal cells through this mechanism. In addition, amiloride in concentrations greater than 10 microm protects against L-arginine-induced retinal cell death.

Cellular Proliferative Effect of Dexamethasone in Immortalized Trabecular Meshwork Cell (TM5) Line

Dexamethasone (DEX), one of the corticosteroid hormones, is one of the most common therapeutic strategies in ophthalmological treatment. Despite its widespread use and clinical efficiency, little is known regarding the specific effects of DEX on cell growth, differentiation and cell death in human trabecular meshwork cells. The presence of the glucocorticoid receptor (GR, dexamethasone receptor) in TM-5 cell line, which was derived from the primary human trabecular meshwork cells, was verified by RT-PCR and western blot analysis. The effects of DEX on the cellular proliferation of TM5 cells were measured by a BrdU incorporation assay. Western blot analysis were used to examine the effects of DEX on the Ras/MEK/ERK signaling pathway. The total Ras, MEK1/2 and ERK1/2 protein levels as well as the levels of activated (phosphorylated) form were both significantly increased by the DEX treatment for 5 days. Both MEK1/2 and ERK1/2 were significantly activated by phosphorylation after 10 minutes. The dependence of this increased cell proliferation on GR activation by DEX and the sustained activation of ERK was examined using RU486 (a GR inhibitor) and U0126 (a MEK inhibitor). Both RU486 and U0126 prevented the induction of cell proliferation by the DEX treatment in the TM5 cells. In conclusion this study demonstrated that GR is expressed in TM5 cells. Secondly, DEX treatment for 5 days stimulates cell proliferation in TM5 cells, and that this increased proliferation effect is mediated by the Ras/MEK/ERK pathway.

A Case of Idiopathic Megacolon Presented by Constipation / 대한소화관운동학회지

The condition of an idiopathically dilated colon appears to be clinically heterogenous, very uncommon, and subsequently often poorly managed. Recently, one case of idiopathic megacolon presented by constipation was investigated. The patient was abruptly constipated 6 months prior to the hospital visit. The results of a barium enema and colonoscopy were nonspecific. On plain abdominal radiographs, the ascending and transverse colon were markedly dilated, and the descending colon was not visible. During the conservative management, which included laxative and prokinetic medication, the clinical symptoms and the colonic dilatations on plain radiographs were reduced, and discharged. After that however, repetitive admissions due to abdominal distension and constipation ensued, and therefore a total colectomy was performed in order to improve the patient's quality of life.

A Case of Idiopathic Megacolon Presented by Constipation / 대한소화관운동학회지

The condition of an idiopathically dilated colon appears to be clinically heterogenous, very uncommon, and subsequently often poorly managed. Recently, one case of idiopathic megacolon presented by constipation was investigated. The patient was abruptly constipated 6 months prior to the hospital visit. The results of a barium enema and colonoscopy were nonspecific. On plain abdominal radiographs, the ascending and transverse colon were markedly dilated, and the descending colon was not visible. During the conservative management, which included laxative and prokinetic medication, the clinical symptoms and the colonic dilatations on plain radiographs were reduced, and discharged. After that however, repetitive admissions due to abdominal distension and constipation ensued, and therefore a total colectomy was performed in order to improve the patient's quality of life.

Effect of Iron and Its Chelators on Vibrio vulnificus Septicemia Experimentally Induced in Mice / 대한피부과학회지

Infection with V. vulnificus resulting in septicemia accompanied with skin gangrene and high mortality of 50% or more freqently occurs in people with liver disenses. And it has also been demonstrated that serum iron, essential to the growth of microorganisms, has been elevated in liver damaged animals. In spite of many efforts to reveal the pathogenesis of this fatal disease, there is no clear conclusion so far. Significant increase or decrease in LD of V. vulnificus (CDC C7184) was observed when mice were treated with ferric arnmonium citrate (FAC) and a specific iron chelator, desferal(Df), originated from Streptomyces pilosus and a broad spectrurn cation chelator, calciurn disodium ethylenediaminetetraacetate (CaEDTA) widly used in heavy metal poisoning treated alone or in combination. The results were obtained as follows. FAC and Df lowered LD to approximately 1.96x 10(3) colony forming unit (CFU) and 9.77x10(2) CFU respectively from 4.46 x 10(5) CFU, LDso of the control group. However, CaEDTA elevated the I D to 4.97 X 10(7) CFU. The LD of the group administered FAC and Df simultaneously was about 9.28x10(1) CFU. Whereas, the LD of the group administered FAC and CaEDTA simultaneously was approximately 7.88 x 10(5), similar to that of the control group. This study demonstrates that there is a close association of the iron with V. vulnificus septicemia and Df lowers LD of the rnice. CaED7A, however, elevated the LD. The author hereby proposes carefully iron chelators such as CaEDTA as an agent for a new adjuvant therapy of the V. vulnificus septicernia.