Tel, Banu Cahide; Zirh, Elham Bahador; Yazgı, Hare; Akyel, Hilal; Zirh, Selim

Aim: Amyloid beta fibrils have been shown to play a role in plaque formation and aggregation in Alzheimer’s disease. Obtaining these fibrils using two main methods and applying them to Alzheimer’s modelling is crucial in understanding the pathology of the disease at the molecular level and identify in therapeutic targets. The aim of our study is to determine the optimum sonication parameters using probe and ultrasonic bath sonication laboratory methods and to demonstrate Alzheimer’s disease modelling at the cellular level. Methods: Lyophilized human peptide amyloid beta 1-42 fibrils (fAβ 1- 42) were subjected to probe sonication for 1 minute with 1, 3 and 5 second on/off pulse applications at varying ambient temperatures (room temperature, ice and ice surrounded by dry ice [ISDI]) for 20, 40 and 60 cycles, respectively. Then, ultrasonic bath sonication was performed in 10 °C water for 1 hour. The length of the fragmented fibrils was quantified by transmission electron microscopy (TEM). fAβ1- 42 at different concentrations was applied to SH-SY5Y cell line. The non-toxic dose and time of fAβ 1-42 application were analysed using the WST-1 assay. Intracellular and extracellular fibrils were visualized with immunofluorescence (IF) labelling. Results: Although, fragmentation was observed under all conditions, it was observed that fibrillar lengths decreased as the on/off pulse times increased, regardless of the number of cycles with ice and dry ice. Additionally, decreasing the temperature increased fibrillar fragmentation. Conclusion: We anticipate that our study will contribute to the literature by developing an effective and economical sonication method for fibrillar fragmentation with two main laboratory methods and obtaining fAβ1-42 that can be used in cells at optimum concentration.

Balbay, Ege Gulec; Cangur, Sengul; Admış, Özlem; Şahin, İbrahim Ethem

Objective: Obstructive Sleep Apnea (OSA) is characterized by recurrent episodes of complete or partial upper airway obstruction during sleep. The role of locally increased inflammation in the upper respiratory tract is known in the pathogenesis of OSA. This study aimed to examine the role of some inflammatory markers in OSA. Materials and Methods: Adult patients who underwent diagnostic polysomnography (PSG) for the first time, were evaluated in this prospective study. Serum levels of neopterin, human cartilage glycoprotein 39 (YKL-40), interleukin-6 (IL-6), and tumor necrosis factor- alpha (TNF-α) were examined in the study group. Results:The study included 165 adult patients. Individuals of 56 who were did not have OSA were taken as the control group. Patients diagnosed with OSA (n=109) were included in the study and divided into two groups mild-moderate and severe based on the OSA apnea-hypopnea index (AHI). The study groups were divided into 3 cathegories: AHI <5 (control) Group 1, AHI 5-15 (mild), and AHI 15-30 (moderate) Group 2, AHI>30 (severe) Group 3. Individuals of 165 who completed the study [Group 1 (n=56), Group 2 (n=69), Group 3 (n=40)] were included in the statistical evaluation. There was a significant difference between the groups in terms of neopterin, YKL-40, and IL-6 values (p<0.05). The median value of IL-6 and neopterin measured in the severe group was significantly higher than the value measured in the control and mild- moderate groups (p<0.001). The mean value of YKL-40 measured in the severe group was significantly higher than the value measured in the control group (p=0.012). No significant difference was observed in TNF-α serum levels of groups. Conclusion: Serum levels of neopterin, YKL-40, and IL-6 were found to be elevated in OSA patients (especially in the severe group).

Yılmaz, Mustafa; Kumbasar, Ulaş; Doğan, Rıza; Taydas, Onur; Dikmen, Erkan; Ariyurek, Orhan Macit; Uysal, Serkan; Demircin, Metin

Objective: The anterior mediastinal masses are composed of neoplasms from many different groups, thymic epithelial tumors being the most common type. Histologic subtype, tumor stage and completeness of resection are considered to be the most important prognostic factors in thymic malignancies. The aim of this study is to evaluate the association between the preoperative Computed Tomography characteristics and the histological types, mostly focusing on thymic neoplasms. Materials and Methods: Preoperative Computed Tomography features and pathologic data of 40 patients who underwent surgery due to an anterior mediastinal mass were retrospectively analyzed. Patients are grouped as thymomas, thymic carcinomas and others. Results: Computed Tomography characteristics such as shape, contour, necrosis, lymph node enlargement, surrounding organization, pathologic invasion pattern, internal density, presence of cystic component, pleural/pericardial effusion and calcification were compared with histologic subtypes. Among these parameters solely pathologic invasion and surrounding organization were statistically different between the groups (p<0.001 and p=0.001, respectively). Correlation between the Computed Tomography and pathologic tumor sizes among histologic subtypes was also analyzed and no statistically significant difference between Computed Tomography and pathologic tumor sizes was detected (p>0,05). Conclusion: According to the results of our study, Computed Tomography imaging has a limited role in predicting stage and malignant potential particularly for thymic neoplasms and anterior mediastinal masses.