4.Evaluation of bonding efficiency between facial silicone and acrylic resin using different bonding agents and surface alterations.
Uttam Sadashiv SHETTY ; Satyabodh Shesharaj GUTTAL
The Journal of Advanced Prosthodontics 2012;4(3):121-126
PURPOSE: The aim of the study was to evaluate the effect of 3 silicone primers and 3 surface characterization of acrylic resin surface on bond strength between silicone elastomer and acrylic resin. MATERIALS AND METHODS: 96 Cosmesil silicones bonded to heat-curing acrylic resin were fabricated with the dimension of 75 x 10 x 3 mm. The 3 primers used in this study were G611 platinum primer, A-330 Gold platinum primer, and cyanoacrylates resin. Specimens without primer were used as control. The 3 types of surface characterization done were retentive holes with 1.5 mm in diameter and 0.5 mm deep, retentive beads of 0.6 mm diameter and the third type which was plain without any characterization. The specimens were then checked for bond strength by subjecting them to 180degrees peel test on a universal testing machine. The obtained results were then subjected to statistical analysis using 2-way ANOVA and Scheffe multiple post hoc procedures. The statistical significance was set at 5% level of significance. RESULTS: The maximum bond strength was seen for samples in which A-330G primer was used followed by G611 primer. The control group showed the minimum bond strength. Surface characterization of retentive holes increased the bond strength considerably as compared to retentive beads and samples without any surface characterization. CONCLUSION: Within the limitations of the study, A-330G primer was more compatible with Cosmesil M511 silicone and has better bonding of Cosmesil to acrylic resin. Retentive holes made on acrylic surface increased the bond strength considerably than those without any surface characterization.
Collodion
;
Cyanoacrylates
;
Platinum
;
Silicone Elastomers
5.A Case of Localized Scleroderma-like Lesion Following Extravasation of Oxaliplatin.
Eun Jung KIM ; Mi Yeon KIM ; Hoon KANG ; Young Min PARK ; Hyung Ok KIM
Korean Journal of Dermatology 2007;45(6):577-580
While extravasation from intravenous lines is common and usually benign, leakage of certain cytotoxic drugs can cause severe tissue injury varying from irritation to necrosis. The severity of tissue injury is dependent on the type and concentration of the chemotherapeutic agent and the quantity injected. Oxaliplatin is a novel class of platinum chemotherapeutic agent used in refractory adenocarcinoma. With increased use of oxaliplatin as a potent anticancer drug, there has been increasing numbers of irreversible local tissue reactions at venous administration sites. This report describes a case of the rapid onset of scleroderma-like lesion following a single episode of oxaliplatin extravasation from an implanted chemo-port in a 72-year-old patient with metastatic gastric cancer.
Adenocarcinoma
;
Aged
;
Humans
;
Necrosis
;
Platinum
;
Stomach Neoplasms
6.In vitro cytotoxicity of a novel platinum(II) coordination complex containing diaminocyclohexane and dichloropropane.
Young Soo RHO ; Sung Goo CHANG ; Woo Tae LEE ; Jee Chang JUNG
The Korean Journal of Physiology and Pharmacology 2001;5(4):359-366
We have synthesized a novel platinum(II) coordination complex containing cis-1,2-diaminocyclohexane (DACH) as a carrier ligand and 1,3-dichloropropane (DCP) as a leaving group. A new series of (Pt(cis-DACH)(DCP))(PC) was evaluated for its cytotoxic: activity on MKN-45 human gastric adenocarcinoma cells and normal primary cultured kidney cells. The new platinum complex has demonstrated high efficacy in the cytotoxicity against MKN-45/P, MKN-45/ADM and MKN-45/CDDP cell-lines. The cytotoxicity of PC against rabbit proximal renal tubular cells, human renal cortical cells and human renal cortical tissues, determined by MTT assay, the (3H)-thymidine uptake and glucose consumption tests, was found to be quite less than those of cisplatin. Based on these results, this novel platinum(II) coordination complex appears to be better for improving antitumor activities with low nephrotoxicity and is a valuable lead in the development of new, clinically available anticancer chemotherapeutic agents.
Adenocarcinoma
;
Cisplatin
;
Glucose
;
Humans
;
Kidney
;
Platinum
7.Lethal Effects of Radiation and Platinum Analogues on Multicellular Spheroids of HeLa Cells.
Journal of the Korean Society for Therapeutic Radiology 1989;7(2):149-156
Multicellul ar tumor spheroids of HeLa cells have been grown in a static culture system. Samples of spheroids were exposed for 2 h to graded concentration of sis-platinum and its analogue, carboplatin, and then response assayed by survival of clonogenic cells. The purpose of present experiment is to clarify the effectiveness of these platinum compounds and to evaluate intrinsic radiosensitivity of cells using spheroids of HeLa cells as an experimental in vitro model. Variations of the drug sensitivity of monolayers as well as spheroids were also evaluated in cell-survival curves. In cia-platinum concentration-survival cutie, there was a large shoulder extending as far as Cq=3.4 mM, after which there was exponential decrease in survival curve having a Co Value of 1.2 mu in spheroids. While the Co for the spheroids was essentially no significant change, but Cq value was larger than that of monolayers. This suggest that the effect of cis-platinum is greater in the monolayer with actively proliferaing cells than hypoxic one. In the carboplatin concentration-survival curves, the Co value of spheroids was 15.0 mM and the ratio with the Co from monolayer cell (32.5 mM) was 0.46, thus indicating that the spheroids had a greater sensitivity to carboplatin than monolayers. Therefore, the effect of carboplatin is mainly on the deeper layers of spheroids acting as hypoxic cell sensitizer. The enhanced effect was obtained for monolayer cells using combined X-ray and carboplatin treatment 2 hours before irradiation. The result shown in isobologram analysis for the level of surviving fraction at 0.01 indicated that the effect of two agents was truely supra-additive. From this experimental data, carboplatin has excited much recept interest as one of the most promising, since it is almost without nephrotoxicity and causes less gastrointestinal toxicity than cia-platinum. Interaction between carboplatin and radiation might play an important role for more effective local tumor control.
Carboplatin
;
Cisplatin
;
HeLa Cells*
;
Humans
;
Platinum Compounds
;
Platinum*
;
Radiation Tolerance
;
Shoulder
;
Spheroids, Cellular*
8.Selective Cytotoxicity of Novel Platinum (II) Coordination Complexes on Human Bladder Cancer Cell-Lines and Normal Kidney Cells.
Jung Tae KIM ; Young Soo RHO ; Jee Chang JUNG
The Korean Journal of Physiology and Pharmacology 2003;7(2):111-117
Cisplatin is often effective in cancer treatment, but its clinical use is limited because of its nephrotoxicity. We have synthesized new platinum (II) coordination complexes (PC-1 & PC-2) containing trans-l and cis-1, 2-diaminocyclohexane (DACH) as carrier ligands and L-3 -phenyllactic acid (PLA) as a leaving group with the aim of reducing nephrotoxicity but maintaining its anticancer activity. In this study, new platinum (II) complex compounds were evaluated for selective cytotoxicity on cancer cell-lines and normal kidney cells. The new platinum complexes have demonstrated high efficacy in the cytotoxicity against human bladder carcinoma cell-lines (T-24/HT-1376). The cytotoxicity of these compounds against rabbit proximal renal tubular cells and human renal cortical tissues, was determined by MTT assay, the [3H]-thymidine uptake and glucose consumption test, and found to be quite less than those of cisplatin. Based on our results, these novel platinum compounds appear to be valuable lead compounds with high efficacy and low nephrotoxicity.
Cisplatin
;
Coordination Complexes*
;
Glucose
;
Humans*
;
Kidney*
;
Ligands
;
Platinum Compounds
;
Platinum*
;
Urinary Bladder Neoplasms*
;
Urinary Bladder*
9.Liposomes as Acitivators of Lipophilic Platinum (2 ) Complexes.
Journal of the Korean Cancer Association 1999;31(1):180-187
PURPOSE: The goal of this study is to understand the activation processes that take place within the liposomal formulation of lipophilic diaminocyclohexane platinum (DACH-Pt) complexes, to identify the activated species of this class of compounds, and to use that information to develop a reproducible liposomal formulation of DACH-Pt complexes. MATERIALS AND METHODS: Liposomal DACH-Pt complexes were prepared by lyophilization-rehydration method using PC, PG and PA. Their intraliposomal stability and biological activity were determined by HPLC and in vitro/in vivo experiments. RESULTS: DACH-Pt complexes in a liposomal formulation have shown significant promise in preclinical studies and clinical phase I, II trials. Interestingly, they are prodrugs which converts into one or more undetennined activated platinum species within the liposomes ex vivo. Our studies have shown that the stability of liposomal DACH-Pt complexes is inversely related with the antitumor activity of those complexes. The configuratian of leaving group in the complexes and pH of the liposome suspension affect significantly the degradation/activation process that takes place within the liposomes. DACH-Pt complexes with linear (L10) leaving groups are more stable than complexes with branched ones (B10 and NDDP), but also significantly less potent. The presence of PG and PA in the liposome is a prerequisite for the degradation/activation process of DACH-Pt complexes. As PG and PA formulation gave more dramatic changes of the original complexes than PC alone due to lower pH, the cytotoxicity and antitumor activity at those fonnulations increased against PC alone. DACH-Pt complexes are very stable in liposomes containing PC alone but inactive in vitro/in vivo experiments. CONCLUSION: These results also support that the active species produced within the liposomal DACH-Pt complexes is DACH-Pt-Cl2.
Chromatography, High Pressure Liquid
;
Hydrogen-Ion Concentration
;
Liposomes*
;
Platinum*
;
Prodrugs
10.Treatment for unresectable gastric cancer.
Tae Yong KIM ; Do Youn OH ; Yung Jue BANG
Journal of the Korean Medical Association 2015;58(3):209-215
Systemic chemotherapy is the cornerstone of treatment for patients with advanced gastric cancer. The combination of fluoropyrimidine and platinum is the most widely used first-line treatment worldwide. In patients with HER2-positive gastric cancer, the combination of trastuzumab (an anti-HER2 monoclonal antibody) and chemotherapy is the standard-of-care. Second-line chemotherapy can also prolong patients' survival after progression; treatment options include cytotoxic chemotherapy (paclitaxel, docetaxel or irinotecan) and/or ramucirumab (an anti-VEGFR2 monoclonal antibody). A number of new targeted-agents are currently being studied, and more personalized approaches will be realized in the near future.
Drug Therapy
;
Humans
;
Neoplasm Metastasis
;
Platinum
;
Stomach Neoplasms*
;
Trastuzumab