Browsing by Author "Erdem, Remzi"

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Deneysel sol varikosel sıçan modelinde anjiyogenez inhibitörü olarak spironolaktonun testis ve izole sol vaz deferens dokuları üzerindeki etkileri
(Başkent Üniversitesi Tıp Fakültesi, 2007) Köse, Mustafa Gökhan; Peşkircioğlu, Levent; Erdem, Remzi
Varikoselin erkek üreme sistemi üzerinde morfolojik ve işlevsel bozukluklara neden olduğu gösterilmiştir. Anjiyogenez mevcut damarlardan yeni damar oluşumunu ifade eder. Varikoselin anjiyogenezi uyardığı gösterilmiştir, ancak anjiyogenezin varikoseldeki etkisi net değildir. Bu çalışmada varikoselin sıçan testisindeki histopatolojik ve izole vaz deferens dokusundaki işlevsel etkileri, anjiyogenezin varikoseldeki fonksiyonu ve anjiyogenez inhibitörü olan spironolaktonun bu fonksiyonları ne derecede etkilediği araştırılmıştır. Çalışmada kullanılan 24 adet erişkin Wistar albino sıçan, deneysel sol varikosel (DSV), varikosel ve spironolakton (V+S), sham ve kontrol grupları olmak üzere 4 eşit gruba ayrıldı. Varikosel sol renal venin parsiyel ligasyonuyla oluşturuldu. V+S grubundaki hayvanlara 20 mg/kg/gün dozunda spironolakton, DSV grubuna ise aynı dozda serum fizyolojik orogastrik gavaj yoluyla verildi. Kırk beş gün sonra tüm hayvanlar sakrifiye edildi. Sağ ve sol testislerdeki morfoloji ve germ hücre değişiklikleri hematoksilen - eozin; anjiyogenez CD 31 immünohistokimyasal boyamayla değerlendirildi. İzole organ banyosunda sol vaz deferens dokusundaki kolinerjik, adrenerjik ve serotonerjik kasılma ve gevşeme yanıtları incelendi. Spironolaktonun biyokimyasl etkilerini görmek için bazal ve işlem sonrasındaki serum sodyum, potasyum ve total testosteron değerleri çalışıldı. Sol testiste DSV ve V+S grubunda spermatogenezde bozulma belirgindi (sırasıyla, p< 0.05 ve p< 0.001), sağ testiste ise gruplar arasında fark yoktu. DSV grubunda mikrodamar yoğunluğu ve anjiyogenez diğer gruplara göre daha fazlaydı. Spironolaktonun DSV grubundaki adrenerjik ve özellikle de serotonerjik yanıtları değiştirme eğiliminde olduğu izlendi. Hiçbir grupta asetilkoline anlamlı yanıt oluşmadı. Bazal ve işlem sonrasındaki sodyum ve total testosteron değerleri arasında fark izlenmedi. Bu bulgulara göre, varikoselde artan anjiyogenezin koruyucu etkisi vardır ve spironolakton testiste anjiyogenezi inhibe ederek spermatogenezin daha da bozulmasına neden olmaktadır. Anjiyogenez ve varikosel arasındaki ilişkinin net olarak tanımlanabilmesi için daha kapsamlı çalışmalara ihtiyaç vardır.
EFFECT OF NEW BASKENT UNIVERSITY ORGAN-PRESERVATION SOLUTION ON THE ACTIN CYTOSKELETON REARRANGEMENT AND APOPTOSIS OF RENAL TUBULAR CELLS: COMPARISON WITH OTHER PRESERVATION SOLUTIONS
(2019) Haberal, Mehmet; Ozdemir, B. Handan; Kirnap, Mahir; Erdem, Remzi; Lux, K. Michael; Bacanli, Didem; AAH-9198-2019
The Effect of Pycnogenol (R) on Spatial Learning and Memory in Rats with Experimental Closed Head Injury
(2017) Kayipmaz, Afsin Emre; Erdem, Remzi; Yilmaz, Cem; Deniz, Emine Ebru; Kavalci, Cemil; Ozdemir, Alperen; Guler, Irem; Caferoglu, Eda; Kalyoncu, Fatma Serra; Guven, Ozgur; 0000-0002-2353-8044; AAK-2948-2021; AAC-2597-2020
Aim: Trauma is a leading cause of emergency admissions. In this study, we investigated the effect of Pycnogenol (R) on spatial learning and memory (SLM) function in rats subjected to closed head injury. Methods: The study was a randomized, experimental study of four groups, each containing six rats. Pycnogenol (R) was administered to rats in two groups (group three and four) daily for five days starting on day one. A Barnes maze was used to test SLM in the rats in all four groups. Group 1: These rats did not have a closed head injury and were not administered Pycnogenol (R). Group 2: On the day three, closed head trauma was inflicted. Group 3: Pycnogenol (R) was administered to the rats. On day three, closed head trauma was inflicted. Group 4: Only Pycnogenol (R) was administered. At the end of day five, the brain tissue of the 24 rats was removed. Results: There were no significant differences between the groups in mean SLM durations on days one through five. No significant differences were detected in the pathological examination between of the four groups. Conclusion: Future studies that employ biochemical markers and free radical levels in the brain are needed.
EVALUATION OF NEW BASKENT UNIVERSITY PRESERVATION SOLUTION FOR LIVER, KIDNEY AND INTESTINE GRAFT DURING COLD ISCHEMIA: PRELIMINARY EXPERIMENTAL ANIMAL STUDY
(2019) Haberal, Mehmet; Kirnap, Mahir; Erdem, Remzi; Ozdemir, B. Handan; Lux, K. Michael; Bacanli, Didem; AAH-9198-2019
Investigation of the Possible Protective Effects of Ketamine and Dantrolene on the Hippocampal Apoptosis and Spatial Learning in Rats Exposed to Repeated Electroconvulsive Seizures as a Model of Status Epilepticus
(2020) Gursoy, Ibrahim Devrim; Barun, Sureyya; Erdem, Remzi; Keskin, Ulya; Kiziltas, Murat; Atilla, Pergin; Muftuoglu, Sevda; Yuce, Deniz; Narin, Firat; Ertunc, Mert; Sara, Yildirim; Canpinar, Hande; 0000-0002-7537-2170; 32705669
AIM: To evaluate the possible neuroprotective effects of ketamine and dantrolene on the hippocampal apoptosis and spatial learning in rats exposed to repeated electroconvulsive seizures (ECS) as a model of status epilepticus (SE). MATERIAL and METHODS: Twenty-four rats were assigned to 4 groups. 1st Group was Sham. 2nd Group was ECS: ECS was induced by ear electrodes via electrical stimulation. The same ECS protocol was applied to the 3th and 4th Groups which received ketamine (40 mg/kg s.c.) or dantrolene (5 mg/kg i.p.) 1 h before each ECS, respectively. Following 30 days of recovery, the cognitive status of the animals was evaluated via Morris Water Maze (MWM). The same experimental protocol was repeated 14 days afterward to evaluate the retention of the memory. Hippocampal apoptosis was examined in corresponding experimental groups. RESULTS: All the animals in four groups learned the task with no significant difference between groups in MWM. The ECS+ketamine group showed memory impairment 14 days afterward. ECS+dantrolene group was not different from controls. ECS caused long term apoptotic processes in dentate gyrus (DG) and non-apoptotic neuronal injury in CA1 and CA2. CONCLUSION: Dantrolene and ketamine inhibited apoptosis and showed neuroprotective effects. Although ketamine and dantrolene inhibited ECS-induced apoptosis and non-apoptotic injury, they did not produce similar effects on memory retention. It will be warranted to evaluate cognitive dysfunction by taking into consideration the other factors in addition to apoptosis and neurodegenerative changes.
Multidrug Resistance 1 (MDR1) 3435C/T Genotyping in Childhood Drug-Resistant Epilepsy
(2014) Saygi, Semra; Alehan, Fusun; Atac, Fatma Belgin; Erol, Ilknur; Verdi, Hasibe; Erdem, Remzi; https://orcid.org/0000-0002-8522-5078; https://orcid.org/0000-0001-6868-2165; https://orcid.org/0000-0002-3530-0463; https://orcid.org/0000-0003-0591-009X; https://orcid.org/0000-0002-7537-2170; 23465586; AAB-1203-2021; ABG-9966-2020; AAK-4825-2021; ABG-9940-2020
Introduction: A mutation at nucleotide position 3435 in exon 26 of the multidrug resistance 1 (MDR1) gene is the most frequently studied polymorphism in relation to multidrug resistance. However, there are conflicting data as to whether the CC or TT genotype of the 3435C>T polymorphism is associated with drug resistance. Methods and results: We investigated the association between this polymorphism in drug-resistant childhood epilepsy by comparison with drug-responsive patients. In total, 59 patients with drug-resistant epilepsy, defined as having four or more seizures within a 12-month period while using three or more AEDs, 60 children with drug-responsive epilepsy who had remained seizure-free for 12 months on their current AED regimen and 76 healthy children were involved in this study. Genotype frequencies in drug-resistant patients were as follows: 32.2% CC, 44.1% CT, 23.7% TT; in the drug-responsive group: 20.0% CC, 50.0% CT, 30.0% TT; in the control group: 24.3% CC, 50.0% CT, 25.7% TT. Comparison of drug-resistant and drug-responsive patients revealed no significant difference in genotype frequency. The findings of the epilepsy patients were not significantly different from those of the healthy control subjects. Conclusions: Our study does not support any significant association between the MDR1 polymorphism and drug-resistant childhood epilepsy. (C) 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
Sıçan izole vajen ve mesane dokularında rho-kinaz inhibisyonuna yaşlılık ve cerrahi menopozun etkileri
(Başkent Üniversitesi Tıp Fakültesi, 2009) Akay, Alaaddin; Peşkircioğlu, Levent; Erdem, Remzi
Menopoz sonrası genitoüriner sistemde en sık karsılasılan sorunlar iritatif üriner yakınmalar ve kadın cinsel fonksiyon bozukluklarıdır. Bu yakınmaların olusmasında düzeyleri değisen seks steroidlerinin mesane ve vajen düz kaslarında meydana getirdikleri fizyolojik değisimler oldukça önemlidir. Düz kas kasılmasında kalsiyum-bağımlı yolaktan baska son zamanlarda kalsiyumdan bağımsız bir yolak olan Rho-kinaz yolağı önem kazanmıstır. Bu çalısmada Rho-kinaz yolağının sıçan izole mesane ve vajen düz kasındaki fizyolojik etkisini ve seks steroidlerindeki değisimin bu yolakla olan iliskisinin arastırılması hedeflendi. Bu amaçla östrojen düzeyinin düstüğü fizyolojik menopoz (yaslılık) ve hem östrojen hem de testosteron düzeyinin azaldığı cerrahi menopoz (ooferektomi) grupları kontrol gruplarıyla karsılastırıldı. Çalısmaya, 18’i genç eriskin (7-9 aylık), 6’sı yaslı (18 ay ve üzeri) olmak üzere 24 adet eriskin disi Wistar albino sıçan dahil edildi. Sıçanlar dört gruba ayrıldı. Bunlar; 1. Kontrol grubu (7-9 ay), 2. Kontrol cerrahi (sham) grubu, 3. Cerrahi menapoz (bilateral ooferektomi) grubu ve 4. Đleri yas (18 ay ve üzeri) grubu, olarak belirlendi. Cerrahi menopoz grubundaki sıçanlara bilateral ooferektomi yapılırken, kontrol cerrahi grubunda ise overler gözlendi ancak herhangi bir girisim yapılmaksızın batın tekrar kapatıldı. Cerrahi menopoz ve sham gruplarının 4 haftalık takibinden sonra tüm sıçanlar sakrifiye edildi. Vajen ve mesane dokularından izole edilen düz kas preparatlarında, Rho-kinaz antagonisti Y-27632 ve çesitli farmakolojik ajanların etkileri izole organ banyosu sisteminde incelendi. Vajen seritlerine, mesane seritlerinden farklı olarak elektriksel alan uyarımı uygulanarak sinirsel aracılı uyarımının fizyolojik yanıtları arastırıldı. Prekontrakte vajen ve mesane düz kaslarında Y-27632 ile konsantrasyon-bağımlı gevseme yanıtları gözlendi. Her iki dokuda da genç, sham ve yaslı gruplar arasında gevseme yanıtlarında anlamlı fark görülmezken, cerrahi menopoz grubu ile genç grubu arasında yüksek konsantrasyonlarda daha belirgin olmak üzere anlamlı fark gözlendi. Sempatik, parasempatik ve nitrerjik yolakların blokajı sonrası Y-27632 ile olusturulan gevseme yanıtları genç, sham ve yaslı gruplarda vajende bir miktar artarken mesanede azaldı. Her iki dokuda ooferektomi grubunda değisiklik gözlenmedi. Vajen dokusunda elektriksel alan uyarımı(EAU) yanıtlarını trifazik olarak gözlemlendi. Öncesinde gevseme, ardından bir kasılma ve “off” yanıtı gözlendi. Vajen dokusunda EAU genç grupta yaslı ve cerrahi menopoz gruplarına göre daha fazla gevseme olusturdu. Fakat tüm gruplarda benzer kasılma yanıtlarına neden oldu. Bu bulgular vajen ve mesane dokusunda Ca2+’dan bağımsız kasılmaya yol açan Rho-kinaz aktivitesinin varlığını düsündürmektedir. Bu çalısmada elde edilen ve Rho-kinaz aktivitesinin fizyolojik menepoz durumunda değismediğini, oysa cerrahi menopoz durumunda arttığını isaret eden bulgular, testosteronun Rho-kinaz üzerinde baskılayıcı yönde tonik bir etkisinin olabileceğini düsündürdü. Seks steroidlerinin yanı sıra mesanede nitrik oksit (NO) düzeyinin azalması da Rho-kinaz aktivitesinin artısına yol açarken, vajende NO Rho-kinaz yolakları arasında böyle bir etkilesim görülmemistir. Bu çalısmadan elde edilen bulguların ileri deneysel ve klinik çalısmalarda desteklenmesi halinde spesifik Rho-kinaz inhibitörü Y-27632 kullanılarak veya testosteron düzeyi düsük hastalarda testosteron replasmanı yapılıp, Rho-kinaz aktivitesi azaltılarak, iritatif üriner semptomlarda ve cinsel disfonksiyonda düzelme olabileceği söylenebilir. Irritative urinary complaints and female sexual dysfunction are the most common genitourinary problems in the postmenopausal period. Physiological changes in the bladder and vaginal smooth muscles which occur due to alterations in the levels of sex steroids are very important causative factors for these complaints. In recent years, beside the calciumdependent pathway, a calcium-independent pathway named as “Rho-kinase pathway”- gained importance in smooth muscle contraction. In this study, the aim was to investigate the physiological effect of Rho-kinase pathway in isolated bladder and vaginal smooth muscles of rat and to show the relationship between this pathway and alterations of the the levels of sex-steroids. For this purpose, physiological menopause (elderly) group in which estrogen levels decrease and surgical menopause (ooferectomy) groups in which both estrogen and testosterone levels decrease are compared with control groups. In this study 24 adult female Wistar albino rats were involved. Eighteen of them were young adults (7-9 months of age) and 6 of them were elderly (18 months of age and older). Rats were divided into four groups; as: 1. Control group (7-9 months), 2. Control surgery (sham) groups, 3. Surgical menopause (bilateral ooferectomy), 4. Advanced age group (18 months and older). Bilateral ooferectomy was performed to surgical menopause group and only ovaries were exposed without any intervention and then abdomen was closed in the control surgery group. All rats were sacrificed after a follow-up of 4 weeks in the sham and surgical menopause groups. The effects of Y-27632 which is a Rho-kinase antagonist and other pharmacological agents on smooth muscle slides isolated from vagina and bladder tissues were investigated in isolated organ bath. Physiological responses of neuronal mediated stimulation were also studies by electrical field stimulation application in vaginal bands, but not in bladder bands. Concentration-dependent relaxation responses to Y-27632 was observed in pre-contracted vaginal and bladder smooth muscles. There was statistically no significant difference in relaxation responses between young, sham and elderly groups in both tissues; where as, the difference was significant between surgical menopause and young groups, more prominent in higher concentrations. After the blockage of sympathetic, parasympathetic and nitrergic pathways, relaxation responses induced by Y-27632 while increasing in vagina a bit, decreased in bladder in young, sham and elderly groups. There was no difference in ooferectomy group in both tissues. We observed the electrical field stimulation (EFS) responses in vaginal tissue as triphasic. Relaxation at the beginning, followed by a contraction and an “off response” were observed. In vaginal tissue, EFS produced more relaxation in young group compared to elderly and surgical menopause groups. But it caused similar contraction responses in all groups. These findings give rise to the thought of presence of Rho-kinase activity, causing Ca2+- independent contraction in vaginal and bladder tissues. The results of this study implying that Rho-kinase activity does not change in physiological menopause, where as increases in surgical menopause pointed a suppressive tonic effect of testosterone on Rho-kinase. Beside sex steroids, decrease in nitric-oxide (NO) levels improved Rho-kinase activity in bladder, but such an interaction couldn’t be determined between NO and Rho-kinase pathways in vagina. If the findings of this study are supported by further experimental and clinical studies, improvement in irritative urinary symptoms and sexual dysfunction could be achieved by using the specific Rho-kinase inhibitor Y-27632 or by testosterone replacement in patients with low testosterone levels.
Technique of Ileobladder and Kidney Transplant in Rats and Pigs
(2018) Haberal, Mehmet; Kirnap, Mahir; Gokce, Oruc N.; Bacanli, Didem; Ersoy, Zeynep; Bayzakov, Mirbek; Torgay, Adnan; Ozdemir, Handan; Erdem, Remzi; 0000-0003-0767-1088; 0000-0002-9678-7818; 0000-0002-7528-3557; 0000-0002-6829-3300; 0000-0002-3462-7632; 0000-0002-7537-2170; 29409436; AAF-3066-2021; AAH-9198-2019; AAQ-8259-2021; X-8540-2019; AAJ-5221-2021; AAJ-8097-2021
Objectives: Kidney transplant is the best choice for treatment of patients with advanced chronic renal disease. However, small, poorly compliant, and unstable bladders can result in major problems for patients. Here, we aimed to develop and evaluate a new ileobladder model. Materials and Methods: Fifteen rats (250-300 g) and 5 pigs (similar to 100 kg) were cared for according to institutional and published guidelines. After general anesthesia, laparotomy was done through midline incision. Ileal loops were prepared for ileobladder. After cystectomy (0.5 cm above the trigone in rats, 1 cm above the trigone in pigs), anastomoses were done between antimesenteric sides of ileal loops and bladder remnant with 6/0 Prolene suture. Three other pigs received simultaneous renal transplant. Results: One rat died on day 1 postsurgery from multiorgan hemorrhage. Two rats survived for 5 days, 3 rats for 7 days, and 3 rats for 11 days; 6 rats were killed for pathologic evaluation after 3 months. One pig survived for 22 days and 1 for 9 days. Of the 3 pigs that received a simultaneous renal transplant, 2 pigs were alive and doing well 80 and 72 days after surgery with normal urinary discharge (1 pig was killed for pathologic evaluation after 3 days). When ileobladder was opened, complete recovery of the anastomosis line was observed. Pathologic examination of the anastomosis sites reported a normal healing process with moderate inflammation and the muscular wall of the intestine showed hypertrophia that nearly reached the size of the bladder muscularis propria. Conclusions: Although we had some complications because no draining procedure was used, in terms of technique, our new ileobladder model is promising for providing functional bladder volume. A larger scale series in the clinical setting is planned. This technique can be useful for small bladders and bladder physiology disorders.