Browsing by Author "Verim, Burcu"

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Citation - WoS: 25
Citation - Scopus: 29
Alterations in Levels of 8-Oxo '-deoxyguanosine and 8-Oxoguanine Dna Glycosylase 1 During a Current Episode and After Remission in Unipolar and Bipolar Depression
(Pergamon-Elsevier Science Ltd, 2020) Ceylan, Deniz; Yilmaz, Selda; Tuna, Gamze; Kant, Melis; Er, Ayse; Ildiz, Aysegul; Verim, Burcu
Introduction: Previous studies showed significant increases in DNA base damage markers and significant alterations in base excision repair enzymes in patients with unipolar and bipolar depression. We aimed to investigate changes in urine 8-Oxo-2'-deoxyguanosine (8-oxo-dG) and gene expression levels of 8-Oxoguanine DNA glycosylase 1 (OGG1) during a current depressive episode and after remission in bipolar and unipolar disorders. Methods: Twenty-four acutely depressed bipolar (BD), 33 unipolar depression (UD) patients and 61 healthy controls were included in the study. Clinical evaluations, blood and urine sampling were completed at baseline and at remission after eight weeks. The urine 8-oxo-dG levels were assessed by liquid chromatography tandem mass spectrometry and adjusted for urine creatinine levels. The gene expression levels of OGG1 were determined from cDNA extracted from blood samples, using real time-polymerase chain reaction. Results: At baseline, patients presented significantly higher levels of 8-oxo-dG (p = 0.008), and lower gene expression of OGG1 (p = 0.024) compared to controls. Levels of either 8-oxo-dG or OGG1 expression did not differ between BD and UD. In patients who remitted by the 8th week (n = 30), 8-oxo-dG decreased significantly (p = 0.001), and gene expression levels of OGG1 increased by 2.95 times compared to baseline levels (p = 0.001). All comparisons were adjusted for age, sex, smoking status and body mass index. Conclusion: Our results suggest that patients with bipolar and unipolar mood disorders present increased 8-oxo-dG and decreased gene expression levels of OGG1 in current depressive episodes, and that these changes might be reversed by the resolution of depressive symptoms. The causal relationship between DNA damage and repair requires further exploration.
Cortical Thickness, Neurocognition and Social Cognition in Euthymic Individuals With Bipolar Disorder and Their Healthy Siblings
(Elsevier Science Inc, 2020) Verim, Burcu; Erdeniz, Burak; Bora, Emre; Ceylan, Deniz; Ildiz, Aysegul; Ozerdem, Aysegul
[Abstract Not Available]
Oxidation Induced Dna Damage and Base Excision Repair During a Current Episode and After Remission in Bipolar and Unipolar Depression
(Wiley, 2020) Ceylan, Deniz; Yilmaz, Selda; Tuna, Gamze; Kant, Melis; Er, Ayse; Ildiz, Aysegul; Verim, Burcu
[Abstract Not Available]
Transdiagnostic Investigation of White Matter Integrity and Cortical Thickness in Cognitive Subgroups Within the Schizophrenia-Bipolar Spectrum
(Elsevier Ireland Ltd, 2026) Verim, Burcu; Demirlek, Cemal; Zorlu, Nabi; Erdeniz, Burak; Akgul, Ozge; Ceylan, Deniz; Bora, Emre
Background: Cognitive deficits are cardinal features of schizophrenia-spectrum disorders (SSD) and bipolar disorder (BD). However, their heterogeneous and overlapping characteristics require a dimensional approach to better understand the neurobiological basis of cognition in the psychosis spectrum. To date, only a few studies have examined the neuroanatomical features of cognitive subgroups in transdiagnostic samples, and white matter microstructural characteristics of these subgroups have not been elucidated. This study aimed to investigate white matter and cortical thickness alterations in cognitive subgroups in the schizophrenia-bipolar spectrum. Methods: Globally Impaired (n = 31) and Near-Normal (n = 28) cognitive subgroups, comprising individuals diagnosed with schizophrenia (SZ), schizoaffective disorder (SAD) or BD, and healthy controls (HCs, n = 29), underwent 3T T1-weighted structural magnetic resonance imaging and diffusion tensor imaging scanning. Fractional anisotropy and cortical thickness measures were compared between the cognitive subgroups and healthy controls. Results: Abnormalities in white matter microstructure were only observed in patients with global cognitive impairment compared to HCs. The Near-Normal subgroup did not differ from HCs in white matter integrity. A bilateral reduction in cortical thickness was observed in both the Globally Impaired and Near-Normal subgroups when compared to HCs. Cortical thickness measures did not differentiate between the cognitive subgroups. Conclusions: While reductions in cortical thickness in frontal and temporal regions appear to be a common feature of SZ and BD, abnormalities in white matter microstructure are associated with global cognitive impairment in the schizophrenia-bipolar spectrum. These original findings may be important in identifying more biologically valid clinical syndromes within the schizophrenia-bipolar spectrum.