PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11727/4810
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Item Prognostic factors associated with cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy in recurrent ovarian cancer(2020) Ayhan, Ali; Akilli, Huseyin; 33020918; AAX-3230-2020; AAJ-5802-2021Objective To identify factors affecting survival for women undergoing cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (HIPEC). Methods A retrospective study at Baskent University School of Medicine, Ankara, Turkey. Data were evaluated for 71 women with recurrent ovarian cancer who underwent cytoreductive surgery with R0 resection plus HIPEC between 2016 and 2019. Potential factors affecting survival (platinum sensitivity, bevacizumab administration before HIPEC, albumin and CA125 levels, presence of ascites, age, number of chemotherapy lines, and time interval between last chemotherapy and HIPEC) were evaluated. Complications of HIPEC were documented. Results The median age was 58 years, and the median follow-up was 12 months. In univariate analyses, platinum sensitivity, albumin level, and time since last chemotherapy cycle affected overall survival. In multivariate Cox regression analysis, use of bevacizumab before HIPEC (hazard ratio [HR], 6.7; 95% confidence interval [CI], 1.39-32.3; P=0.018) and presence of ascites (HR, 5.3; 95% CI, 1.65-17.5; P=0.005) were independent negative prognostic factors. Seven (8.9%) women experienced grade III-IV complications. Conclusion In recurrent ovarian cancer, HIPEC is a promising treatment with mild-to-moderate toxicity. However, the presence of ascites and progression under bevacizumab treatment before HIPEC seem to be negative prognostic factors; these findings will be important for patient selection.Item Transscleral Delivery of Bevacizumab-Loaded Chitosan Nanoparticles(2019) Ugurlu, Nagihan; Asik, Mehmet Dogan; Cakmak, Hasan Basri; Tuncer, Sema; Turk, Mustafa; Cagil, Nurullah; Denkbas, Emir Baki; 30841975Purpose: The aim of this study was to synthesize bevacizumab-loaded nanoparticles and evaluate their effects on the treatment of posterior segment diseases via subtenon injections. Methods: Bevacizumab-loaded chitosan nanoparticles (BLCNs) were synthesized by the ionic gelation method, and their physicochemical characteristics and in vitro release profile were studied. The BLCNs were characterized using atomic force microscopy (AFM), FTIR spectroscopy, dynamic light scattering, and scanning electron microscopy. The BLCNs were delivered into rabbits' eyes via posterior subtenon injections. An immunohistochemical evaluation of the ocular tissues was performed, and the vitreous humor and serum bevacizumab levels were measured by ELISA. Results: Bevacizumab-loaded chitosan nanoparticles with a diameter of 80 to 380 nm were prepared and characterized. In vitro studies showed that after the first 5 days of the experiment, a significant increase in the drug release maintained the desired drug dosage for 3 weeks. Immunohistochemical in vivo studies revealed that there were BLCNs penetrating through the sclera. Furthermore, the intravitreal bevacizumab concentration reached a maximum concentration of 18 mu g/ml, and it decreased to 6 mu g/ml after only a week. Conclusion: The results revealed that subtenon injection of BLCNs is a promising alternative to intravitreal injections. In addition to the ELISA studies, immunohistochemical experiments confirmed that BLCNs enable transscleral bevacizumab penetration, and BLCN usage may provide the required bevacizumab levels for the treatment of posterior segment diseases.Item Can serial monitoring of serum Vascular Endothelial Growth Factor (VEGF), Nitric Oxide (NO), and Angiotensin II (ANGII) levels have predictive role during Bevacizumab treatment?(2014) Sumbul, Ahmet Taner; Disel, Umut; Sezgin, Nurzen; Sezer, Ahmet; Kose, Fatih; Besen, Ali Ayberk; Sumbul, Zehra; Abali, Huseyin; Ozyilkan, OzgurBackground: Standard treatment of colorectal cancer includes both cytostatic chemotherapy and targeted therapies. Bevacizumab, targeting the VEGF receptor, is one of the primary targeted therapies that achieve better response rate and survival rate as compared to combination chemotherapy. To the best of our knowledge, there is no established single marker that can be used as a predictive marker in bevacizumab therapy. Material/Methods: We enrolled 24 patients with the diagnosis of metastatic colorectal cancer in our study. During the study, 2 blood samples were drawn from patients before the first cycle and after the sixth cycle of bevacizumab therapy. Serum levels of VEGF, ANG II, and NO were recorded. Results: While the change across VEGF levels was found to be a statistically significant decreasing trend (p=0.009), this decrease was not found to be correlated with treatment response and hypertension development. Additionally, no statistically significant difference was found in terms of NO and ANG II levels. Conclusions: This study showed a significant decrease in serum VEGF, but failed to show a significant change in NO and ANG II levels during bevacizumab treatment. Although no significant correlation was found between the presence of hypertension and markers, most patients (83%) had an increase in their blood pressure. Our results suggest that dynamic monitoring of NO and ANG II, along with VEGF, may not be useful as predictive markers for bevacizumab treatment in colorectal cancer.Item Comparison of the inhibitory effect of different doses of subconjunctival bevacizumab application in an experimental model of corneal neovascularization(2018) Ulas, Burak; Altan-Yaycioglu, Rana; Bal, Nebil; 30046522; AAG-3306-2019; AAL-4440-2020AIM: To evaluate the inhibitory effect of subconjunctival bevacizumab as single- and multiple-dose application, and compare their effects on corneal neovascularization in a rat model. METHODS: Thirty adult Sprague-Dawley rats were used in this experimental study. The central cornea of the rats was cauterized chemically. The rats were randomly enrolled into three groups. All groups received subconjunctival injections. In Group 1 (control group, n=10), 0.05 mL 0.9% NaCl solution was injected on the first day. In Group 2 (single-dose group, n=10), 0.05 mL bevacizumab (1.25 mg) was injected on the first day. In Group 3 (multiple-dose group, n=10), four doses of 0.05 mL bevacizumab (1.25 mg) were injected on the first, third, fifth and seventh day. Slit-lamp examination of all rats was performed at the third and ninth day. Digital images of the corneas were taken and analyzed using image analysis software to calculate corneal neovascularization area. All rats were sacrificed on the tenth day. In corneal sections, the number of blood vessels, state of inflammation and collagen formation was evaluated histopathologically. RESULTS: In Group 3, corneal edema grades were significantly lower than Group 1 and Group 2 (P=0.02, and P=0.035, respectively). The mean percentage of neovascularized corneal area in Group 3 was significantly lower than Group 2 (P=0.005). On histopathological examination, Group 2 and Group 3 showed significantly less number of blood vessels than Group 1 (P=0.005, and P=0.001, respectively). Additionally, Group 3 showed significantly less number of blood vessels compared to Group 2 (P=0.019). Inflammation and edema grades were significantly lower in Group 3 compared to Group 1 (P=0.001). CONCLUSION: Subconjunctival bevacizumab injection is effective in inhibition of newly formed corneal neovascularization. The multiple-dose bevacizumab treatment seems to be more effective compared to single-dose treatment.