Application of Several Special Staining Methods for Paraffin Sections on Epon-Embedded Semithin Sections

Aim: This study aimed to compare several specific staining protocols recommended for paraffin sections and toluidine blue and light green double staining combination to be tried for the first time with routine toluidine blue staining on semithin epon sections. Material and Methods: Samples of 1x1x1 mm were taken from the liver, skin, and aorta tissues of Wistar albino adult rats. Tissue samples were fixed with 5% glutaraldehyde at +4º C overnight, postfixed with 1% osmium tetroxide for one hour, and then, blocked with Epon 812 after processing. Semithin sections of 1 μm thickness were obtained from the epon blocks. Sections were stained with Altmann’s method (for mitochondria), Verhoeff’s method (for elastic fibers), Gordon&Sweets’ silver impregnation method (for type III collagen), toluidine blue and light green double staining combination (for type I collagen) and routine toluidine blue method. Results: In liver sections, mitochondria in hepatocytes were differentiated by the Altmann method, and stromal type III collagen fibers were distinguished with Gordon&Sweets’ method. Elastic lamellar structures were easily observed in black in the aortic sections stained with the Verhoeff method. Successful results were obtained in the staining of dermal type I collagen with toluidine blue and light green double staining in skin sections. Conclusion: Since the specific staining tried for the first time gave positive results in epon sections, it was concluded that these methods can be used to determine the localization of cellular and intercellular components that are aimed to be examined at the ultrastructural level

Comparison of Biomethane Yields of Two Different Methanogenic Bacteria Cultures at Different Temperature

The Research Question of the study is “How does the biogas production and biomethane content that are produced by the Methanosarcina thermophila and Methanobrevibacter ruminantium change at 37℃ (mesophilic temperature conditions); 55℃ (thermophilic temperature conditions) by using the same amount of 100.0 mL stock solutions of each methanogenic bacteria cultures by feeding with %8 dry matter content substrate every 16 hours until reaching twentieth day at constant conditions.’ In this study, I aimed to compare the biomethane yields of two different methanogenic bacteria in thermophilic (55℃) and mesophilic (37℃) temperature conditions using pasteurized cow manure as substrate. Pasteurization via autoclaving was necessary to avoid contamination by native bacteria that is abundant in the digestive tract of the animal. The experiment was conducted with biodigesters with a working volumes of 1 liters, with stock cultures of bacteria kindly provided by the institution that this experiment took place. The substrate solution which were given every sixteen hours until reaching twentieth day and recorded the volume of biogas in liters. Then by the help of the results (volume of biogas) that were taken every sixteen hours, the cumulative biogas production was calculated of each different types of bacteria Methanosarcina thermophila and Methanobrevibacter ruminantium, were compared statistically and the hypothesis was supported. The result of the experiment showed that, improvement of biogas production and biomethane content at thermophilic conditions, Methanosarcina thermophila produced the highest amount of biogas in liters. At mesophilic conditions, Methanobrevibacter ruminantium produced the highest amount of biogas in liters. Overall biomethane content per given volume of biogas did not changed significantly according to T-test by considering the results of experiment. The p value for Mesophilic Conditions (37℃) is 7.04239×10-15. p value of the investigation were calculated as 2.46299×10-8 for Thermophilic Condition. As a result of the P value those two bacteria Methanosarcina thermophila and Methanobrevibacter ruminantium are able to produce highest volume of biogas at their optimum conditions

Analysis of the DOK1 gene in breast cancer

Breast cancer, which is the most common type of cancer among women, is a heterogenous disease. It results from progressive accumulation of genetic and epigenetic alterations in different genes. The Dok1 protein has been identified as the major substrate of protein tyrosine kinases in hematopoietic cells. It is considered as a tumor suppressor due to the reports which describe its inhibitory effect on major oncogenic signaling pathways such as Mek/Erk/PI3k/Akt and Wnt/beta-catenin. In this study, we investigated the mutation frequency of the DOK1 gene in 118 breast tumors using Sanger sequencing and DOK1 mRNA expression level in 63 breast cancer samples using qRT-PCR methods. Although the mutation frequency was low DOK1 mRNA expression levels were significantly reduced (63.5%) in the tumors compared to adjacent non-cancerous tissue. We also correlated expression changes with clinicopathological characteristics. Low mRNA levels correlated with age (p = 0.01) and c-erbB-2 (p = 0.05). In most of the previous reports, down-regulation of DOK1 mRNA expression has been associated with promoter methylation. We identified four different coding sequence alterations in 5.1% (6/118) of the tumor samples. However, all of these alterations were located in the functional domains of the protein. Therefore, these mutations may affect the function and/or cellular localization of the protein and contribute to cancer progression by this way. In conclusion our data indicate that DOK1 acts as a tumor suppressor in breast cancer and association of Dok1 with the c-erbB-2 mediated mechanism of action in breast cancer needs to be investigated

Dr. Lütfi Doğan'ın biyografisi

Ankara : İhsan Doğramacı Bilkent Üniversitesi İktisadi, İdari ve Sosyal Bilimler Fakültesi, Tarih Bölümü, 2014.This work is a student project of the The Department of History, Faculty of Economics, Administrative and Social Sciences, İhsan Doğramacı Bilkent University.by Özer, Abdürrahim

1990-2000 Yılları Arasında İstanbul’da Yüksek Doz Uyuşturucu Ölümleri

Toprak S, Akgül E, Gunaydin U, Ersoy G, Sirin G, Sam B. 1990-2000 Yılları Arasında İstanbul’da Yüksek Doz Uyuşturucu Ölümleri. Türkiye Klinikleri Adli Tıp ve Adli Bilimler Dergisi. 2007, 4:95-10