Browsing by Author "Özdemir Ö."

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    Effects of a DNA Demethylating Agent - 5-Azacytidine - on Testicular Morphology during Mouse Embryo Development
    (Okajima Foria Anatomica Yaponika Henshubu, 1999) Bulut H.E.; Özdemir Ö.; Başimoglu-Koca Y.; Korkmaz M.; Atalay A.
    DNA methylation is an epigenetical mechanism that plays crucial roles in cellular differentiation and tissue development in embryogenesis. The aim of the present study was to determine the effects of a demethylating agent, 5-azacytidine, on testicular development during embryonal life in mouse. Ten pregnant mice were administered 5-azacytidine (5-azaC) (i.p 2mg/kg of agent dissolved in 0.1 mg/ml PBS) during 8th (Group 1), 11th (Group 2), 14th (Group 3) and 18th (Group 4) days of pregnancy periods and male siblings of these animals were obtained (experimental groups) whereas the control group animals received no treatment and siblings of this group were also obtained. Testicular tissues from all groups were taken 20 days after birth and examined at the light and electron microscopical levels. All pregnancies were terminated in Group 1 animals, therefore no observations could be done in this group. While Group 2 and 3 siblings showed distinctive kongenital abnormalities such as; anancephaly, growth failure, cleft palate, extremity abnormalities, supernumerary ribs and whirled shaped-tails, no such abnormalities were observed in Group 4 when compared to the control group. Microscopical examination of testicular tissues in groups 2 and 3 demonstrated cellular disintegration of spermatocytes in seminiferous tubules. In addition, cytoplasmic vacuoles and thickening of the basement membrane were also evident in both groups 2 and 3. Apoptotic-like cells were seen especially in group 2 and rarely in group 3. There were no structural alterations in group 4 animals, except a decreased number of spermatocytes in seminiferous tubules when compared to the control group, possibly indicating the completion of embryogenesis in this group. In conclusion, it could be suggested that the demethylating agent 5-azacytidine may trigger an unknown gene reactivation during early embryogenesis possibly affecting the cell and tissue differentiation in developing mammalian embryos.
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    Efficacy of subsequent treatments in patients with hormone-positive advanced breast cancer who had disease progression under CDK 4/6 inhibitor therapy
    (BioMed Central Ltd, 2023) Karacin C.; Oksuzoglu B.; Demirci A.; Keskinkılıç M.; Baytemür N.K.; Yılmaz F.; Selvi O.; Erdem D.; Avşar E.; Paksoy N.; Demir N.; Göksu S.S.; Türker S.; Bayram E.; Çelebi A.; Yılmaz H.; Kuzu Ö.F.; Kahraman S.; Gökmen İ.; Sakin A.; Alkan A.; Nayır E.; Uğraklı M.; Acar Ö.; Ertürk İ.; Demir H.; Aslan F.; Sönmez Ö.; Korkmaz T.; Celayir Ö.M.; Karadağ İ.; Kayıkçıoğlu E.; Şakalar T.; Öktem İ.N.; Eren T.; Urul E.; Mocan E.E.; Kalkan Z.; Yıldırım N.; Ergün Y.; Akagündüz B.; Karakaya S.; Kut E.; Teker F.; Demirel B.Ç.; Karaboyun K.; Almuradova E.; Ünal O.Ü.; Oyman A.; Işık D.; Okutur K.; Öztosun B.; Gülbağcı B.B.; Kalender M.E.; Şahin E.; Seyyar M.; Özdemir Ö.; Selçukbiricik F.; Kanıtez M.; Dede İ.; Gümüş M.; Gökmen E.; Yaren A.; Menekşe S.; Ebinç S.; Aksoy S.; İmamoğlu G.İ.; Altınbaş M.; Çetin B.; Uluç B.O.; Er Ö.; Karadurmuş N.; Erdoğan A.P.; Artaç M.; Tanrıverdi Ö.; Çiçin İ.; Şendur M.A.N.; Oktay E.; Bayoğlu İ.V.; Paydaş S.; Aydıner A.; Salim D.K.; Geredeli Ç.; Yavuzşen T.; Doğan M.; Hacıbekiroğlu İ.
    Background: There is no standard treatment recommended at category 1 level in international guidelines for subsequent therapy after cyclin-dependent kinase 4/6 inhibitor (CDK4/6) based therapy. We aimed to evaluate which subsequent treatment oncologists prefer in patients with disease progression under CDKi. In addition, we aimed to show the effectiveness of systemic treatments after CDKi and whether there is a survival difference between hormonal treatments (monotherapy vs. mTOR-based). Methods: A total of 609 patients from 53 centers were included in the study. Progression-free-survivals (PFS) of subsequent treatments (chemotherapy (CT, n:434) or endocrine therapy (ET, n:175)) after CDKi were calculated. Patients were evaluated in three groups as those who received CDKi in first-line (group A, n:202), second-line (group B, n: 153) and ≥ 3rd-line (group C, n: 254). PFS was compared according to the use of ET and CT. In addition, ET was compared as monotherapy versus everolimus-based combination therapy. Results: The median duration of CDKi in the ET arms of Group A, B, and C was 17.0, 11.0, and 8.5 months in respectively; it was 9.0, 7.0, and 5.0 months in the CT arm. Median PFS after CDKi was 9.5 (5.0–14.0) months in the ET arm of group A, and 5.3 (3.9–6.8) months in the CT arm (p = 0.073). It was 6.7 (5.8–7.7) months in the ET arm of group B, and 5.7 (4.6–6.7) months in the CT arm (p = 0.311). It was 5.3 (2.5–8.0) months in the ET arm of group C and 4.0 (3.5–4.6) months in the CT arm (p = 0.434). Patients who received ET after CDKi were compared as those who received everolimus-based combination therapy versus those who received monotherapy ET: the median PFS in group A, B, and C was 11.0 vs. 5.9 (p = 0.047), 6.7 vs. 5.0 (p = 0.164), 6.7 vs. 3.9 (p = 0.763) months. Conclusion: Physicians preferred CT rather than ET in patients with early progression under CDKi. It has been shown that subsequent ET after CDKi can be as effective as CT. It was also observed that better PFS could be achieved with the subsequent everolimus-based treatments after first-line CDKi compared to monotherapy ET. © 2023, The Author(s).
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    Correction: Efficacy of subsequent treatments in patients with hormone-positive advanced breast cancer who had disease progression under CDK 4/6 inhibitor therapy (BMC Cancer, (2023), 23, 1, (136), 10.1186/s12885-023-10609-8)
    (BioMed Central Ltd, 2023) Karacin C.; Oksuzoglu B.; Demirci A.; Keskinkılıç M.; Baytemür N.K.; Yılmaz F.; Selvi O.; Erdem D.; Avşar E.; Paksoy N.; Demir N.; Göksu S.S.; Türker S.; Bayram E.; Çelebi A.; Yılmaz H.; Kuzu Ö.F.; Kahraman S.; Gökmen İ.; Sakin A.; Alkan A.; Nayır E.; Uğraklı M.; Acar Ö.; Ertürk İ.; Demir H.; Aslan F.; Sönmez Ö.; Korkmaz T.; Celayir Ö.M.; Karadağ İ.; Kayıkçıoğlu E.; Şakalar T.; Öktem İ.N.; Eren T.; Erul E.; Mocan E.E.; Kalkan Z.; Yıldırım N.; Ergün Y.; Akagündüz B.; Karakaya S.; Kut E.; Teker F.; Demirel B.Ç.; Karaboyun K.; Almuradova E.; Ünal O.Ü.; Oyman A.; Işık D.; Okutur K.; Öztosun B.; Gülbağcı B.B.; Kalender M.E.; Şahin E.; Seyyar M.; Özdemir Ö.; Selçukbiricik F.; Kanıtez M.; Dede İ.; Gümüş M.; Gökmen E.; Yaren A.; Menekşe S.; Ebinç S.; Aksoy S.; İmamoğlu G.İ.; Altınbaş M.; Çetin B.; Uluç B.O.; Er Ö.; Karadurmuş N.; Erdoğan A.P.; Artaç M.; Tanrıverdi Ö.; Çiçin İ.; Şendur M.A.N.; Oktay E.; Bayoğlu İ.V.; Paydaş S.; Aydıner A.; Salim D.K.; Geredeli Ç.; Yavuzşen T.; Doğan M.; Hacıbekiroğlu İ.
    Following publication of the original article [1], the authors reported an error in the author name of Enes Erul. Incorrect: Enes Urul Correct: Enes Erul, The original article [1] has been corrected. © 2023, The Author(s).