1.Investigation of flexural strength and cytotoxicity of acrylic resin copolymers by using different polymerization methods.
Onur SAHIN ; Ali Kemal OZDEMIR ; Mehmet TURGUT ; Ali BOZTUG ; Zeynep SUMER
The Journal of Advanced Prosthodontics 2015;7(2):98-107
PURPOSE: The aim of this study was to appraise the some mechanical properties of polymethyl methacrylate based denture base resin polymerized by copolymerization mechanism, and to investigate the cytotoxic effect of these copolymer resins. MATERIALS AND METHODS: 2-hydroxyethyl methacrylate (HEMA) and isobutyl methacrylate (IBMA) were added to monomers of conventional heat polymerized and injection-molded poly methyl methacrylate (PMMA) resin contents of 2%, 3%, and 5% by volume and polymerization was carried out. Three-point bending test was performed to detect flexural strength and the elasticity modulus of the resins. To determine the statistical differences between the study groups, the Kruskall-Wallis test was performed. Then pairwise comparisons were performed between significant groups by Mann-Whitney U test. Agar-overlay test was performed to determine cytotoxic effect of copolymer resins. Chemical analysis was determined by FTIR spectrum. RESULTS: Synthesis of the copolymer was approved by FTIR spectroscopy. Within the conventional heat-polymerized group maximum transverse strength had been seen in the HEMA 2% concentration; however, when the concentration ratio increased, the strength decreased. In the injection-molded group, maximum transverse strength had been seen in the IBMA 2% concentration; also as the concentration ratio increased, the strength decreased. Only IBMA showed no cytotoxic effect at low concentrations when both two polymerization methods applied while HEMA showed cytotoxic effect in the injection-molded resins. CONCLUSION: Within the limitations of this study, it may be concluded that IBMA and HEMA may be used in low concentration and at high temperature to obtain non-cytotoxic and durable copolymer structure.
Denture Bases
;
Elastic Modulus
;
Hot Temperature
;
Polymerization*
;
Polymers*
;
Polymethyl Methacrylate
;
Spectroscopy, Fourier Transform Infrared
;
Spectrum Analysis
2.Letter to the Editor: Investigation of Efficacy of Mitomycin-C, Sodium Hyaluronate and Human Amniotic Fluid in Preventing Epidural Fibrosis and Adhesion Using a Rat Laminectomy Model.
Elif BOLAT ; Erdogan KOCAMAZ ; Zeki KULAHCILAR ; Ali YILMAZ ; Abdullah TOPCU ; Mevci OZDEMIR ; Mehmet Erdal COSKUN
Asian Spine Journal 2014;8(4):540-540
No abstract available.
Amniotic Fluid*
;
Animals
;
Female
;
Fibrosis*
;
Humans
;
Hyaluronic Acid*
;
Laminectomy*
;
Mitomycin*
;
Rats*
3.Letter to the Editor: Investigation of Efficacy of Mitomycin-C, Sodium Hyaluronate and Human Amniotic Fluid in Preventing Epidural Fibrosis and Adhesion Using a Rat Laminectomy Model.
Elif BOLAT ; Erdogan KOCAMAZ ; Zeki KULAHCILAR ; Ali YILMAZ ; Abdullah TOPCU ; Mevci OZDEMIR ; Mehmet Erdal COSKUN
Asian Spine Journal 2014;8(4):540-540
No abstract available.
Amniotic Fluid*
;
Animals
;
Female
;
Fibrosis*
;
Humans
;
Hyaluronic Acid*
;
Laminectomy*
;
Mitomycin*
;
Rats*
4.The Effects of Intravenous Ephedrine During Spinal Anesthesia for Cesarean Delivery: A Randomized Controlled Trial.
Iclal Ozdemir KOL ; Kenan KAYGUSUZ ; Sinan GURSOY ; Ali CETIN ; Zeki KAHRAMANOGLU ; Fikret OZKAN ; Caner MIMAROGLU
Journal of Korean Medical Science 2009;24(5):883-888
We designed a randomized, double-blinded study to determine the efficacy and safety of 0.5 mg/kg intravenous ephedrine for the prevention of hypotension during spinal anesthesia for cesarean delivery. Patients were randomly allocated into two groups: ephedrine group (n=21) and control group (n=21). Intravenous preload of 15 mL/kg lactated Ringer's solution was given. Shortly after the spinal injection, ephedrine 0.5 mg/kg or saline was injected intravenous for 60 sec. The mean of highest and lowest heart rate in the ephedrine group was higher than those of control group (P<0.05). There were significant lower incidences of hypotension and nausea and vomiting in the ephedrine group compared with the control group (8 [38.1%] vs. 18 [85.7%]); (4 [19%] vs. 12 [57.1%], respectively) (P<0.05). The first rescue ephedrine time in the ephedrine group was significantly longer (14.9+/-7.1 min vs. 7.9+/-5.4 min) than that of the control group (P<0.05). Neonatal outcome were similar between the study groups. These findings suggest, the prophylactic bolus dose of 0.5 mg/kg intravenous ephedrine given at the time of intrathecal block after a crystalloid fluid preload, plus rescue boluses reduce the incidence of hypotension.
Adult
;
*Anesthesia, Spinal/adverse effects
;
Blood Pressure/drug effects
;
*Cesarean Section
;
Ephedrine/administration & dosage/*therapeutic use
;
Female
;
Heart Rate/drug effects
;
Humans
;
Hypotension/chemically induced/prevention & control
;
Injections, Intravenous
;
Postoperative Nausea and Vomiting/prevention & control
;
Pregnancy
;
Vasoconstrictor Agents/administration & dosage/*therapeutic use
5.Investigation of Efficacy of Mitomycin-C, Sodium Hyaluronate and Human Amniotic Fluid in Preventing Epidural Fibrosis and Adhesion Using a Rat Laminectomy Model.
Elif BOLAT ; Erdogan KOCAMAZ ; Zeki KULAHCILAR ; Ali YILMAZ ; Abdullah TOPCU ; Mevci OZDEMIR ; Mehmet Erdal COSKUN
Asian Spine Journal 2013;7(4):253-259
STUDY DESIGN: A retrospective study. PURPOSE: The aim of this study was to evalute the effects of mitomycin-C, sodium hyaluronate and human amniotic fluid on preventing spinal epidural fibrosis. OVERVIEW OF LITERATURE: The role of scar tissue in pain formation is not exactly known, but it is reported that scar tissue causes adhesions between anatomic structures. Intensive fibrotic tissue compresses on anatomic structures and increases the sensitivity of the nerve root for recurrent herniation and lateral spinal stenosis via limiting movements of the root. Also, neuronal atrophy and axonal degeneration occur under scar tissue. METHODS: The study design included 4 groups of rats: group 1 was the control group, groups 2, 3, and 4 receieved antifibrotic agents, mitomycin-C (group 2), sodium hyaluronate (group 3), and human amniotic fluid (group 4). Midline incision for all animals were done on L5 for total laminectomy. Four weeks after the surgery, the rats were sacrificed and specimens were stained with hematoxylin-eosin and photos of the slides were taken for quantitive assesment of the scar tissue. RESULTS: There was no significant scar tissue in the experimental animals of groups 2, 3, and 4. It was found that there was no significant difference between drug groups, but there was a statistically significant difference between the drug groups and the control group. CONCLUSIONS: This experimental study shows that implantation of mitomycin-C, sodium hyaluronate and human amniotic fluid reduces epidural fibrosis and adhesions after spinal laminectomy in rat models. Further studies in humans are needed to determine the complications of the agents researched.
Amniotic Fluid*
;
Animals
;
Atrophy
;
Axons
;
Cicatrix
;
Equidae
;
Female
;
Fibrosis*
;
Humans*
;
Hyaluronic Acid*
;
Laminectomy*
;
Mitomycin*
;
Models, Animal
;
Neurons
;
Rats*
;
Retrospective Studies
;
Sodium*
;
Spinal Stenosis
6.Pretreatment Photopenia on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Scans Predicts Poor Prognosis in Nasopharyngeal Cancer Patients Undergoing Concurrent Chemoradiotherapy
Erkan TOPKAN ; Ugur SELEK ; Hüseyin MERTSOYLU ; Yurday OZDEMIR ; Ahmet KUCUK ; Nese TORUN ; Ali Ayberk BESEN
Clinical and Experimental Otorhinolaryngology 2020;13(4):407-414
Objectives:
. To investigate the influence of pretreatment primary tumor or nodal photopenia (PP) on 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT), an indicator of tumor ischemia, on survival results of nasopharyngeal cancers (NPCs) treated with concurrent chemoradiotherapy (C-CRT).
Methods:
. The pre-C-CRT FDG PET-CT scans of 104 patients with NPC (cT1-4 N0-3 M0) were retrospectively examined to determine the presence of PP (PP+). Our primary endpoint was the influence of PP+ on overall survival (OS), while the progression-free survival (PFS) and locoregional PFS (LRPFS) constituted the secondary endpoints.
Results:
. The PP+ was detected in 29 (27.9%): nine (8.7%), seven (6.7%), and 13 (12.5%) in the primary tumor alone, primary tumor plus neck nodes, and neck nodes alone, respectively. Because the PP+ cases were small by count per location, all comparative analyses were performed according to overall PP+/ PP– status instead of per detected site. At a median follow-up of 67.8 months (range, 9 to 130 months), the median survival times were not reached (NR) for the entire population, while 5-year OS, LRPFS, and PFS rates were 73.3%, 68.2%, and 63.4%, respectively. Comparatively the PP+ patients exhibited significantly poorer median OS (49.8 months vs. NR, P<0.001), LRPFS (40.7 months vs. NR, P=0.001), and PFS (31.8 months vs. NR, P=0.002) durations than their PP– counterparts. Furthermore, the PP+ retained its independent prognostic significance in multivariate analysis (P<0.001).
Conclusion
. Present results uncovered the pre-C-CRT PP as an independent predictor of poor prognosis for NPC patients, which underscore the requirement for the fortification of the local and systemic treatments in hypoxic NPCs.
7.Endocan and Non-Dipping Circadian Pattern in Newly Diagnosed Essential Hypertension.
Tolga CIMEN ; Murat BILGIN ; Ahmet AKYEL ; Mehmet Ali FELEKOĞLU ; Ali NALLBANI ; Seyda OZDEMIR ; Gönül ERDEN ; Alpaslan OZTÜRK ; Mehmet DOĞAN ; Ekrem YETER
Korean Circulation Journal 2016;46(6):827-833
BACKGROUND AND OBJECTIVES: Non-dipper hypertension is frequently accompanied by endothelial dysfunction and activation. Previous studies suggested that endocan may be a novel endothelial dysfunction marker. This study aims to investigate the association between circadian blood pressure (BP) pattern and plasma endocan levels together with high-sensitivity C-reactive protein (hsCRP) in patients with newly diagnosed untreated hypertension. SUBJECTS AND METHODS: Twenty-four hour ambulatory blood pressure monitoring was recorded in 35 dipper, 35 non-dipper hypertensives and 35 healthy controls. Endocan levels were measured by enzyme-linked immunosorbent assay. Serum levels of hsCRP were also recorded. RESULTS: Despite similar daytime and 24-hour average BP values between dippers and non-dippers, statistically significant high nocturnal BP was accompanied by a non-dipping pattern (Systolic BP: 132±9 vs. 147±11 mmHg; Distolic BP: 80±7 vs. 91±9 mmHg, respectively, p<0.001 for both). Non-dipper patients demonstrated higher endocan levels compared to dippers and normotensives (367 (193-844) pg/mL, 254 (182-512) pg/mL and 237 (141-314) pg/ml, respectively, p<0.001). HsCRP levels were significantly higher in non-dippers than the other groups (p=0.013). In a multivariate logistic regression analysis, endocan (p=0.021) and hsCRP (p=0.044) were independently associated with a non-dipping pattern. CONCLUSION: Elevated endocan levels were found in non-dipper groups. Endocan and hsCRP were found to be independently associated with a non-dipping pattern. We suggest that elevated levels of endocan in non-dipper hypertensive patients might be associated with a longer duration of exposure to high BP. These results point to the possible future role of endocan in selection of hypertensive patients at higher risk or target organ damage.
Blood Pressure
;
Blood Pressure Monitoring, Ambulatory
;
C-Reactive Protein
;
Enzyme-Linked Immunosorbent Assay
;
Humans
;
Hypertension*
;
Logistic Models
;
Plasma
8.The Effect of Hepatitis C Virus Infection on Insulin Resistance in Chronic Haemodialysis Patients.
Ali OZDEMIR ; Berrin YALINBAS ; Umut SELAMET ; Meltem ERES ; Funda TURKMEN ; Fatma KUMBASAR ; Berna MURAT ; A Tayfun KESKIN ; Yildiz BARUT
Yonsei Medical Journal 2007;48(2):274-280
PURPOSE: To investigate the contribution of HCV infection to insulin resistance in chronic haemodialysis patients. MATERIALS AND METHODS: The study was performed with 55 patients who were on regular haemodialysis therapy three times per week. Of the 55 patients, 34 (20 females and 14 males with an average age of 40.9 years) were anti-HCV (+) and were defined as the HCV (+) group. The remaining 21 patients (8 females and 11 males with an average age of 50 years) were negative for HCV and other viral markers and were defined as the HCV (-) group. BMI of all patients were below 27. Insulin resistance (IR) was calculated according to the HOMA formula and patients were called HOMA-IR (+) if their HOMA scores were higher than 2.5. All of the HOMA-IR (+) patients in both groups were called the HOMA-IR (+) subgroup. None of the patients had a history of drug use or any diseases that were related to insulin resistance except uremia. In both groups and the healthy control group, insulin and glucose levels were studied at three different venous serum samples taken at 5- minute intervals after 12 hours of fasting. Other individual variables were studied at venous serum samples taken after 12 hours of fasting. RESULTS: HOMA scores were (3)2.5 in 22 of 34 HCV (+) patients (64.7%) and 7 of 21HCV (-) patients (33.33%) (p=0.024). Insulin levels of HCV (+) group (13.32 +/- 9.44mIU/mL) were significantly higher than HCV (-) (9.07 +/- 7.39mIU/mL) and the control groups (6.40 +/- 4.94mIU/ mL) (p=0.039 and p=0.021 respectively). HCV (+) patients were younger (40.94 +/- 17.06 and 52.62 +/- 20.64 years, respectively) and had longer dialysis duration (7.18 +/- 3.61 and 2.91 +/- 2.69 years, respectively). Significant positive correlations of HOMA score with insulin (r=0.934, p=0.000) and fasting glucose levels (r=0.379, p=0.043) were found in the HOMA- IR (+) subgroup. Also, a significant positive correlation was found between ALT and insulin levels in the HOMA IR (+) subgroup. C-peptide levels of both HCV (+) and (-) groups were significantly higher than the control group (p < 0.001). There were not any significant correlations between HOMA score and some of the other individual variables including levels of triglyceride, ferritin, ALT, iPTH and Mg in any of the groups. CONCLUSION: In chronic haemodialysis patients; HCV infection is related to a high prevalence of insulin resistance, higher insulin and glucose levels.
*Renal Dialysis
;
Middle Aged
;
Male
;
Kidney Failure, Chronic/*complications
;
*Insulin Resistance
;
Insulin/blood
;
Hyperinsulinism/epidemiology
;
Humans
;
Hepatitis C/*epidemiology
;
Female
;
C-Peptide/blood
;
Adult
9.Prognostic Significance of Retroperitoneal Lymphadenectomy, Preoperative Neutrophil Lymphocyte Ratio and Platelet Lymphocyte Ratio in Primary Fallopian Tube Carcinoma: A Multicenter Study.
Kemal GUNGORDUK ; Ibrahim E ERTAS ; Aykut OZDEMIR ; Emrah AKKAYA ; Elcin TELLI ; Salih TASKIN ; Mehmet GOKCU ; Ahmet Baris GUZEL ; Tufan OGE ; Levent AKMAN ; Tayfun TOPTAS ; Ulas SOLMAZ ; Askin DOGAN ; Mustafa Cosan TEREK ; Muzaffer SANCI ; Aydin OZSARAN ; Tayyup SIMSEK ; Mehmet Ali VARDAR ; Omer Tarik YALCIN ; Sinan OZALP ; Yusuf YILDIRIM ; Firat ORTAC
Cancer Research and Treatment 2015;47(3):480-488
PURPOSE: The purpose of this study is to evaluate the prognostic role of preoperative neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) and the need for para-aortic lymphadectomy in patients with primary fallopian tube carcinoma (PFTC). MATERIALS AND METHODS: Ninety-one patients with a diagnosis of PFTC were identified through the gynecologic oncology service database of six academic centers. Clinicopathological, surgical, and complete blood count data were collected. RESULTS: In univariate analysis, advanced stage, suboptimal surgery, and NLR > 2.7 were significant prognostic factors for progression-free survival, whereas in multivariate analysis, only advanced stage and suboptimal surgery were significant. In addition, in univariate analysis, cancer antigen 125 > or = 35 U/mL, ascites, advanced stage, suboptimal surgery, NLR > 2.7, PLR > 233.3, platelet count > or =400,000 cells/mm3, staging type, and histological subtype were significant prognostic factors for overall survival (OS); however, in multivariate analysis, only advanced stage, suboptimal surgery, NLR > 2.7, and staging type were significant. Inclusion of pelvic and para-aortic lymphadenectomy in surgery showed significant association with longer OS, with a mean and median OS of 42.0 months and 35.5 months (range, 22 to 78 months), respectively, vs. 33.5 months and 27.5 months (range, 14 to 76 months), respectively, for patients who underwent surgery without para-aortic lymphadenectomy (hazard ratio, 3.1; 95% confidence interval, 1.4 to 5.7; p=0.002). CONCLUSION: NLR (in both univariate and multivariate analysis) and PLR (only in univariate analysis) were prognostic factors in PFTC. NLR and PLR are inexpensive and easy tests to perform. In addition, patients with PFTC who underwent bilateral pelvic and para-aortic lymphadenectomy had longer OS.
Ascites
;
Blood Cell Count
;
Blood Platelets*
;
Diagnosis
;
Disease-Free Survival
;
Fallopian Tubes*
;
Female
;
Humans
;
Lymph Node Excision*
;
Lymphocytes*
;
Multivariate Analysis
;
Neutrophils*
;
Platelet Count