Browsing by Author "Bulduk, Erkut Baha"

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Citation Count: 0
Alzheimer hastalığında Kallikrein-6, 7 ve potasyum kanal proteinlerinin olası rolü
(2021) Bulduk, Erkut; Yıldırım, Filiz; Yıldırım, Zuhal; Surgical Sciences
Amaç: Alzheimer hastalığının (AH) oluşum mekanizması kesin olarak bilinmemekle birlikte AH’dan sorumlu başlıca iki protein, senile plakların yapısındaki beta amiloid ve nörofibriler yumakların yapısındaki tau proteinidir. Hastalığa yol açan en önemli etmenlerden biri çözünür olmayan amiloid çökeltilerin oluşumu, diğeri ise artmış tau fosforillenmesidir. Kallikreinler, nöronal hasar ve işlev kaybı ile belirgin AH’nın etiyolojisinde rol oynayan, serin proteazların bir alt familyasıdır. Kallikrein (KLK)-6 ve KLK-7’nin merkezi sinir sisteminde (MSS) yüksek seviyelerde bulunan yaşa bağlı proteaz olduğu bilinmektedir. Daha once AH’ı gibi nörodejeneratif hastalıklarda yer alan hücre dışı proteinlerin proteolizine karıştığı gösterilmiştir. Bu çalışmada KLK-6 ve KLK-7’nin AH patogenezindeki olası rolünü ve potasyum kanal proteinleri arasındaki ilişkiyi araştırmayı amaçladık. Yöntem: Çalışmaya Polatlı Duatepe Devlet Hastanesinde takip edilen yaşları 65’in üzerinde olan 35 AH ve rutin tarama amacıyla nöroloji polikliniğine başvuran kognitif durumu normal olarak değerlendirilen 35 sağlıklı birey (control grubu) dahil edildi. 12 saat açlığı takiben antekübital venden alınan kan örnekleri 4°C’de 2500xg’de 10 dakika santrifüj edilerek, serum örneklerinde KLK-6 ve KLK-7 ile içeri doğru düzeltici potasyum kanalı (KCNJ3) ve iki gözenekli potasyum kanalı (KCNK9) protein düzeyleri enzim-bağımlı immunosorbent assay (ELISA) ile ölçüldü. Gruplar arasındaki fark T-test ile incelendi. p<0.05 istatistiksel olarak anlamlı kabul edildi. Bulgular: Gruplar arasında yaş ve cinsiyet açısından bir fark saptanmadı (p>0.05). Alzheimer grubu control grubu ile karşılaştırıldığında serum KLK-6 ve KLK-7 düzeyleri anlamlı olarak artarken (p<0.05), KCNJ3 ve KCNK9 protein düzeylerinde bir fark saptanmadı (p>0.05). Sonuç: Beyinde anormal protein katlanmasının ve birikmesinin önüne geçilememesinin AH’ye yol açtığı düşünülmektedir. Bu araştırmanın bulgularına göre KLK- 6 ve KLK-7 düzeyleri ile AH’nın patolojisi arasında bir ilişki saptandı.
Citation Count: 0
Does the Dominant Hand Factor Have an Effect on Postoperative Improvement in the Surgical Treatment of Ulnar Nerve Entrapment?
(2020) Bulduk, Erkut; Ataizi, Zeki Serdar; Surgical Sciences
Objectives: Ulnar nerve entrapment is the most frequently encountered entrapment neuropathy after the carpal tünelsyndrome. Surgical treatment is usually suggested to patients who do not benefit from conservative treatment. In thisstudy, we aimed to examine the effect of the dominant hand on the clinical results of ulnar nerve decompression surgery.Methods: 48 (25 D, 23 N-D) patients were included in the study. The Edinburgh Handedness Inventory was used toidentify the dominant hand of patients included in the study. Visual analogue scale (VAS) values were evaluated preand postoperatively.Results: 25 patients underwent surgery on the dominant hand and 23 patients had surgery to their non-dominanthand. The VAS values of patients who underwent non-dominant hand surgery were lower than those who underwentsurgery on the dominant hand.Conclusion: In our study, the recovery time of patients operated on the dominant side due to ulnar nerve compressionwas longer than the patients operated on the non-dominant side. In our opinion, exercise and protection programs fordominant hands in the postoperative period of ulnar nerve entrapment surgery, in addition to a good surgical technique, positively affects the results of surgical treatment.
Citation Count: 0
Effects of Total and Subtotal Glial Tumor Resection on Survival
(2020) Ercan, Serdar; Ataizi, Zeki S; Ataizi, Fulya; Bulduk, Erkut Baha; Surgical Sciences
Objectives: Glial tumors are treated with a multidisciplinary team approach including specialists in brain surgery, radiology, pathology, radiation oncology and medical oncology. Surgery is one of the main treatment options. However,the effect of resection volume on prognosis is still uncertain. The aim of this study is to investigate the relationshipbetween the residual tumor volume and survival of the patients who were operated with the diagnosis of intracranialglial tumor in the last 5 years.Methods: Of 49 patients, 30 underwent total resection and 19 underwent subtotal resection.Results: The average surveys of total resection were 13.6 (6-32 months) months. 4 of 6 patients with anaplastic astrocytoma survived and the mean survey was 26.5 (4-45) months. The survey of subtotal resection group was significantlyshorter than the other TR group.Conclusion: As a result, recovery was inversely increased with residual tumor volume
Citation Count: 0
Efficacy of Gamma-Knife Radiosurgery in Grade 2 and Grade 3Meningioma: A Single-Center, Long-Term Follow-Up Study
(2021) Bulduk, Erkut Baha; Demirci, Harun; Karaaslan, Burak; Demirtaş, Oğuz Kağan; Emmez, Ömer Hakan; Kurt, Gökhan; Surgical Sciences
Objectives: Gamma-Knife Radiosurgery (GKR) is a safe and effective treatment option in patients who have a high riskof complications in skull base and eloquent area-based tumors, in those to whom total surgery cannot be applied. Thepurpose was to analyze the results of radiosurgery in patients who underwent GKR for the residues or recurrent tumorsin high grade meningiomas. Methods: A retrospective screening was performed on patients who underwent GKR at Gazi University between 2004and 2018. The gender, mean age, location, volume, complications, size changes after GKR were noted. Results: A total of 35 (79.5%) patients were treated with Grade 2, and 9 (20.5%) were treated with Grade 3 meningio mas. The mean follow-up period was 48 months (3-108). The mean volume was noted as 9339 mm3 . The tumor controlrates after GKR were determined as 94% in Grade 2 and 55% in Grade 3 meningiomas. Conclusion: GKR can be applied as a safe and effective method for postoperative tumor control in high grade meningiomas.
Citation Count: 1
Kafa Travmasında Rehabilitasyon
(2020) Bulduk, Erkut; Ercan, Serdar; Surgical Sciences
Travmatik beyin hasarı (TBH), 21. yüzyılda dünya genelinde önemini devam ettiren global bir sağlık sorunudur. Hastanın ve ailesininyaşamını ciddi bir şekilde etkileyen, birden fazla tıbbi, bilişsel, davranışsal, ekonomik ve sosyal sonuçlara yol açan TBH’da ilkhedef hasarın önlenmesidir. Hasar geliştikten sonra etkisini sınırlandırmak, fonksiyonel iyileşmeyi hızlandırmak ve artırmak içinmultidisipliner nörorehabilitasyon çok önemlidir. Kafa travması ile ilişkili çok sayıda tıbbi, bilişsel ve davranışsal sorunlar dikkatledeğerlendirilmeli ve topluma yeniden entegrasyon olasılığını artırmak için her bireye özel tedavi planlanması çok önemlidir. Sonuçolarak nörorehabilitasyon sürekli olarak gelişen bir alandır. Beynin iyileşme yeteneği hakkında daha fazla bilgi edindikçe, yeniterapötik müdahaleler ve rehabilitasyon teorileri ortaya çıkacaktır.
Citation Count: 1
Neuroprotective effects of adrenomedullin in experimental traumatic brain injury model in rats
(Turkish Assoc Trauma Emergency Surgery, 2022) Emmez, Gokcen; Bulduk, Erkut Baha; Yildirim, Zuhal; Surgical Sciences
BACKGROUND: Traumatic brain injuries cause damages in the brain in several ways, which include cell death because of edema, disruption of the blood-brain barrier, shear stress, and ischemia. In this study, we investigated the effects of adrenomedullin (AM) on oxidative stress and inflammation after head traumas in a rat model. METHODS: Eighteen male adult Wistar albino rats were randomized into three groups (n=6). No traumas were applied to the control (C) group. Traumas were applied in line with Marmarau trauma model in the trauma group. The rats in the AM treatment group were treated with post-traumatic 12 mu g/kg i.p. AM in addition to the trauma group. The rats were followed for 7 days in all groups and were then sacrificed. Brain tissues and blood samples were taken. RESULTS: In the trauma group, both tissue and serum MDA, TNF-alpha, and IL-6 levels were significantly increased compared to the control group (p<0.05). In the AM-treated group, serum TNF-alpha levels were significantly decreased compared to the trauma group (p<0.05). In the trauma group, both tissue and serum GSH levels were significantly decreased compared to the control group (p<0.05). In the trauma group, serum Vitamin D3 levels were significantly decreased compared to the control group (p<0.05). In the AM-treated group, both tissue and serum GSH levels were significantly increased compared to the trauma group (p<0.05). CONCLUSION: These results indicate that AM has neuroprotective effects on traumatic brain injury in a rat model.
Citation Count: 0
The Possible Role of Kallikrein-6, 7, and Potassium Channel Proteins in Alzheimer’s Disease
(Refik Saydam National Public Health Agency (RSNPHA), 2021) Bulduk,E.B.; Yildirim,F.; Yildirim,Z.; Surgical Sciences
Objective: Although the formation mechanism of Alzheimer’s Disease (AD) is not known with certainty, two major proteins, beta amyloid of senile plaques and tau protein of neurofibrillary tangels are responsible for AD. One of the major factors in the development of the disease is the formation of in soluble amyloid deposits, and the other one is the increased tau phosphorylation. Kallikreins (KLK’s) are a sub-family of serine proteases that play a role in the etiology of AD which is characterized by neuronal damage and loss of function.Kallikrein (KLK)-6 and KLK-7 are known to be age-related protease and are found at high levels in the central nervous system (CNS). It was previously shown to be involved in proteolysis of extracellular proteins implicated in neurodegenerative diseases such as AD. In this study, we aimed to investigate the possible role of KLK-6 and KLK-7 in the pathogenesis of AD and the relationship between potassium channel proteins. Methods: A total of 35 Alzheimer’s patients over the age 65 years, followed-up by Polatlı Duatepe Government Hospital and 35 healthy individuals (control group) admitted to the neurology clinic for routine screening with cognitive status considered normal were included in this study. After a 12-hour hunger, KLK-6 and KLK-7 were measured with inwardly rectifying potassium channel protein (KCNJ3), and two-pore potassium channel protein (KCNK9) levels were measured by the Enzyme-Linked Immuno Sorbent Assay (ELISA) in the serum of the blood samples which were taken from the antecubital vein after centrifuging for 10 minutes at 2500xg. The differences between the two groups were tested by T- test. A value of p<0.05 was considered statistically significant. Results: All the groups were matched for age and gender, but not statistically significant difference was observed (p>0.05). According to our findings, serum KLK- 6 and KLK-7 levels of Alzheimer’s group were significantly increased (p<0.05). A significant difference was not detected when the levels of serum KCNJ3 and KCNK9 of the Alzheimer’s group compared with the control group (p>0.05). Conclusion: It is thought that the failure in preventing the abnormal protein folding and accumulation leads to AD in the brain. According to the findings of the present study, a positive correlation was detected between the levels of KLK-6 and KLK-7 and AD’s pathology. © 2021. All Rights Reserved.
Citation Count: 2
Stereotactic Radiosurgery after Subtotal Resection of Critically-Located Grade I Meningioma: A Single-Center Experience and Review of Literature
(Turkish Neurosurgical Soc, 2021) Karaaslan, Burak; Celtikci, Emrah; Bulduk, Erkut Baha; Borcek, Alp Ozgun; Kurt, Gokhan; Kaymaz, Memduh; Emmez, Hakan; Surgical Sciences
AIM: To analyze the results of stereotactic radiosurgery in 295 patients with residual Grade I meningiomas located at parasellar region, petroclival region, cerebellopontine angle and parasagittal region. MATERIAL and METHODS: A total of 295 patients with Grade 1 residual Meningiomas (197 women, 98 men), who were treated by adjuvant radiosurgery in Gazi University Gamma Knife Center between 2004-2015 were analyzed. WHO Grade 2 and 3 meningiomas were not included in our study. Minimum radiological follow-up was 24 months. The median follow-up was 54 months. The tumor volume, location, treatment dose, morbidity, progression free survival and tumor control rate were analyzed. RESULTS: The median tumor volume was 5.2 cm(3) (0.04-39.7), median age was 50 (20-80), median dose was 14 Gy and tumor control rate was 94.5% (stationary in 85.0%, volume reduction in 9.5%). Increase in tumor volume was seen in 16 patients (5.5%) and re-operation was performed in 5 of them (1.6%). Stereotactic radiosurgery was performed again for 8 patients (2.7%).The location of the tumors was as follows: 39.3% parasellar region, 20% cerebellopontine angle, 13.6% petroclival and 27.1% was parasagittal, falcine or convexity. Major morbidities were detected in 6 (2%) patients. Minor morbidities were detected in 18 (6.1%) patients. CONCLUSION: Stereotactic radiosurgery is an effective and safe treatment modality for residual Grade I meningiomas.
Citation Count: 2
Thioredoxin System and miR-21, miR-23a/b and let-7a as Potential Biomarkers for Brain Tumor Progression: Preliminary Case Data
(Elsevier Science inc, 2022) Kilic, Nedret; Boyacioglu, Ozge; Saltoglu, Gamze Turna; Bulduk, Erkut Baha; Kurt, Gokhan; Korkusuz, Petek; Basic Sciences; Surgical Sciences
BACKGROUND: The thioredoxin system and microRNAs (miRNAs) are potential targets for both cancer progression and treatment. However, the role of miRNAs and their relation with the expression profile of thioredoxin system in brain tumor progression remains unclear. METHODS: In this study, we aimed to determine the expression profiles of redox components Trx-1, TrxR-1 and PRDX-1, and oncogenic miR-21, miR-23a/b and let-7a and oncosuppressor miR-125 in different brain tumor tissues and their association with increasing tumor grade. We studied Trx-1, TrxR-1, and PRDX-1 messenger RNA expression levels by quantitative real-time polymerase chain reaction and protein levels by Western blot and miR-23a, miR-23b, miR-125a, miR-21, and let-7a miRNA expression levels by quantitative real-time polymerase chain reaction in 16 glioma, 15 meningioma, 5 metastatic, and 2 benign tumor samples. We also examined Trx-1, TrxR-1, and PRDX-1 protein levels in serum samples of 36 patients with brain tumor and 37 healthy volunteers by enzyme-linked immunosorbent assay. RESULTS: We found that Trx-1, TrxR-1, and PRDX-1 presented high messenger RNA expression but low protein expression in low-grade brain tumor tissues, whereas they showed higher protein expression in sera of patients with low-grade brain tumors. miR-23b, miR-21, miR-23a, and let-7a were highly expressed in low-grade brain tumor tissues and positively correlated with the increase in thioredoxin system activity. CONCLUSIONS: Our findings showed that Trx-1, TrxR-1, miR-21, miR-23a/b, and let-7a might be used for brain tumor diagnosis in the clinic. Further prospective studies including molecular pathway analyses are required to validate the miRNA/Trx system regulatory axis in brain tumor progression.