Browsing by Author "Yilmaz, Engin"

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A cross-sectional overview of SARS-CoV-2 genome variations in Turkey
(WALTER DE GRUYTER GMBH, 2021-01-01) Ergunay, Koray; Kaya, Mucahit; Serdar, Muhittin; Akyon, Yakut; Yilmaz, Engin
Objectives: We assessed SARS-CoV-2 genome diversity and probable impact on epidemiology, immune response and clinical disease in Turkey. Materials and methods: Complete genomes and partial Spike (S) sequences were accessed from the Global Initiative on Sharing Avian Influenza Data (GISAID) database. The genomes were analysed for variations and recombinations using appropriate softwares. Results: Four hundred ten complete genomes and 206 S region sequences were included. Overall, 1,200 distinct nucleotide variations were noted. Mean variation count was 14.2 per genome and increased significantly during the course of the pandemic. The most frequent variations were identified as A23403G (D614G
Analysis of Mitochondrial DNA Control Region D-Loop in Gliomas: Result of 52 Patients
(TURKISH NEUROSURGICAL SOC, 2021-01-01) Yuksel, Sirin Kilicturgay; Ozduman, Koray; Yilmaz, Engin; Pamir, M. Necmettin; Akyerli, Cemaliye B.
AIM: To investigate the effect of mitochondrial DNA (mtDNA) variants mainly in D-loop on glioma biology. MATERIAL and METHODS: Sanger sequencing of D-loop (15971-16451 bp) for 52 glioma patients was performed and the variations were statistically analyzed for gender, WHO classification, morphological grade, IDH/TERT status. RESULTS: Total of 122 variations (51 unique) were identified in 52 patients. C16223T, T16189C, T16311C and T16126C variants were frequently detected. The total variation number was statistically non-significant among the analyzed categories. When individual variants were considered, T16311C and T16224C were statistically significant for WHO classification (p=0.033), morphological grade (p=0.036) and gender (p=0.039), respectively. CONCLUSION: Total variation number in D-loop was not found to be related with clinical variables. Our data suggests that individual variants may play a critical role in glioma biology.
Effects of Regular Kefir Consumption on Gut Microbiota in Patients with Metabolic Syndrome: A Parallel-Group, Randomized, Controlled Study
(MDPI, 2019-01-01) Bellikci-Koyu, Ezgi; Sarer-Yurekli, Banu Pinar; Akyon, Yakut; Aydin-Kose, Fadime; Karagozlu, Cem; Ozgen, Ahmet Gokhan; Brinkmann, Annika; Nitsche, Andreas; Ergunay, Koray; Yilmaz, Engin; Buyuktuncer, Zehra
Several health-promoting effects of kefir have been suggested, however, there is limited evidence for its potential effect on gut microbiota in metabolic syndrome This study aimed to investigate the effects of regular kefir consumption on gut microbiota composition, and their relation with the components of metabolic syndrome. In a parallel-group, randomized, controlled clinical trial setting, patients with metabolic syndrome were randomized to receive 180 mL/day kefir (n = 12) or unfermented milk (n = 10) for 12 weeks. Anthropometrical measurements, blood samples, blood pressure measurements, and fecal samples were taken at the beginning and end of the study. Fasting insulin, HOMA-IR, TNF-alpha, IFN-gamma, and systolic and diastolic blood pressure showed a significant decrease by the intervention of kefir (p <= 0.05, for each). However, no significant difference was obtained between the kefir and unfermented milk groups (p > 0.05 for each). Gut microbiota analysis showed that regular kefir consumption resulted in a significant increase only in the relative abundance of Actinobacteria (p = 0.023). No significant change in the relative abundance of Bacteroidetes, Proteobacteria or Verrucomicrobia by kefir consumption was obtained. Furthermore, the changes in the relative abundance of sub-phylum bacterial populations did not differ significantly between the groups (p > 0.05, for each). Kefir supplementation had favorable effects on some of the metabolic syndrome parameters, however, further investigation is needed to understand its effect on gut microbiota composition.
Gut Microbiota and Oral Contraceptive Use in Overweight and Obese Patients with Polycystic Ovary Syndrome
(ENDOCRINE SOC, 2020-01-01) Eyupoglu, Nesrin Damla; Ergunay, Koray; Acikgoz, Aylin; Akyon, Yakut; Yilmaz, Engin; Yildiz, Bulent Okan
Context: Polycystic ovary syndrome (PCOS) is a common and complex endocrine disorder. Emerging animal and human data point to various changes in microbiota that could be linked with the syndrome. However, the effects of therapeutic approaches on gut microbial composition in women with PCOS remain unknown. Objective: We aimed to assess whether gut microbial composition is altered in PCOS and to determine the potential impact of oral contraceptive (OC) use on gut microbiota. Design: Prospective observational study. Setting: Tertiary referral hospital. Patients and Other Participants: The study included 17 overweight/obese patients with PCOS and 15 age- and body mass index-matched healthy control women. Main Outcome Measures: At baseline, clinical, hormonal, and metabolic evaluations and gut microbial composition assessment by 16S rRNA gene amplicon sequencing were performed for both groups. All measurements were repeated in patients after receiving an OC along with general lifestyle advice for 3 months. Results: Alpha and beta diversity did not show a difference between patients with PCOS and healthy controls at baseline and remained unaltered after 3 months of OC use in the PCOS group. Relative abundance of Ruminococcaceae was higher in PCOS (P= 0.006) and did not show a significant change after treatment. Conclusion: Women with PCOS have an increased abundance of Ruminococcaceae, whereas short-term OC use does not alter compositional features of gut microbiota in the syndrome.
Probable alterations in fecal bacterial microbiota by somatostatin receptor analogs in acromegaly
(WALTER DE GRUYTER GMBH, 2020-01-01) Sendur, Suleyman Nahit; Ergunay, Koray; Akyon, Yakut; Brinkmann, Annika; Serdar, Muhittin; Dagdelen, Selcuk; Erbas, Tomris; Nitsche, Andreas; Yilmaz, Engin
Objective: Data on bacterial diversity and microbiota alterations in acromegaly are currently lacking. The effects of somatostatin receptor analogs on gut microbiota remain unknown. The objective of this study was to determine microbiota alterations in patients with acromegaly and to assess the effects of somatostatin receptor analogs on gut microbiota. Methods: The study was designed as a cross-sectional case-control research and three cohorts, comprising individuals with acromegaly without medical therapy (n=5), acromegaly receiving octreotide acetate (OCT) (n=8) and healthy controls (n=5), were evaluated. Results: No statistically-supported changes in Bacteroidetes, Firmicutes, Proteobacteria and Actinobacteria abundance were observed. Bacteroidaceae, Odoribacteraceae, Porphyromonadaceae, Prevotellaceae and Alistipes families of Bacteroidetes and Bifidobacterium genus of the Actinobacteria phyla were detected, without overt differences. Variations in Clostridia, Erysipelotrichaceae and Veillonellaceae were not significant, while Lactobacillales were increased in individuals receiving OCT. Moreover, Akkermansia mucinophila was present in patients under OCT treatment. Conclusion: Our preliminary results suggest that the bacterial community profile under OCT treatment may facilitate a colonic microenvironment for improved glucose metabolism. Alterations in the gut microbiota may be a factor affecting diabetes development during somatostatin analog treatment in acromegalic patients.
The molecular footprints of COVID-19
(WALTER DE GRUYTER GMBH, 2020-01-01) Yilmaz, Engin; Akyon, Yakut; Serdar, Muhittin
COVID-19 is the third spread of animal coronavirus over the past two decades, resulting in a major epidemic in humans after SARS and MERS. COVID-19 is responsible of the biggest biological earthquake in the world. In the global fight against COVID-19 some serious mistakes have been done like, the countries' misguided attempts to protect their economies, lack of international co-operation. These mistakes that the people had done in previous deadly outbreaks. The result has been a greater economic devastation and the collapse of national and international trust for all. In this constantly changing environment, if we have a better understanding of the hostvirus interactions than we can be more prepared to the future deadly outbreaks. When encountered with a disease which the causative is unknown, the reaction time and the precautions that should be taken matters a great deal. In this review we aimed to reveal the molecular footprints of COVID-19 scientifically and to get an understanding of the pandemia. This review might be a highlight to the possible outbreaks.