Yazar "Kükner, A. Şahap" seçeneğine göre listele
Listeleniyor 1 - 8 / 8
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Administration of high dose intravitreal melatonin degenerates retinal cells in guinea pigs(2004) Yılmaz, Turgut; Naziroǧlu, Mustafa; Çelebi, Serdal; Özercan, Hanifi İbrahim; Kükner, A. ŞahapThe purpose of this study was to investigate the influence of intravitreally injected different doses of melatonin on retinal morphology. The right eyes of 35 male albino guinea pigs were used. The animals were classified randomly into five groups in equal numbers. First group was used as control and received intravitreal injection of placebo. Groups 2, 3, 4 and 5 received intravitreally injections of melatonin at 50, 100, 150 and 200 ?g/body weight (BW) each, respectively. The animals were sacrificed 15 days after the injections. The eyes were enucleated and processed for light microscopic evaluation.Intravitreal injection of melatonin at doses ranging from 50 to 150 ?g did not induce morphological changes, although a higher thickness of the inner plexiform layer (IPL) was found in Group 5 compared to other groups (p < 0.05). The mean retinal ganglion cell (RGC) counts were found to be lower in Group 5 compared to other groups (p < 0.05).Our findings indicate that intravitreal injection of melatonin at doses ranging from 50 to 150 ?g/BW does not induce morphological changes. The dose of 200 ?g/BW produced significant damage including retinal ganglion cell loss and formation of retinal edema. © 2004 Elsevier Ireland Ltd. All rights reserved.Öğe Effects of intraperitoneal vitamin E, melatonin and aprotinin on leptin expression in the guinea pig eye during experimental uveitis(Wiley, 2006) Kükner, Aysel; Çolakoğlu, Nermin; Serin, Didem; Alagöz, Gürsoy; Çelebi, Serdal; Kükner, A. ŞahapPurpose: To observe ultrastructural changes and leptin expression in the guinea pig eye during experimental uveitis (EU) and the effects of vitamin E, melatonin and aprotinin on leptin expression. Methods: Thirty male guinea pigs were randomly classified into five groups. Group 1 was the control group. Groups 2, 3, 4 and 5 received intravitreal injections of bovine serum albumin (BSA) to induce EU. At the same time on the third day, groups 3 (EU + vitamin E), 4 (EU + melatonin) and 5 (EU + aprotinin) received intraperitoneal vitamin E (150 mg/kg), melatonin (10 mg/kg) and aprotinin (20 000 IU/kg), respectively. On the sixth day, histopathological and clinical scoring of inflammation were performed, and leptin expression was investigated in the retina, choroid, sclera, episclera and cornea, and compared. Result: There was a remarkable increase in leptin expression in the retina, choroid, sclera and episclera in the EU group. Leptin expression in the treatment groups was similar to that in the control group. At light and electron microscopic levels, ganglion cells were oedematous and inner plexiform layer thickness had increased in the EU group retinas. Oedema was decreased in the treatment groups. Comparison of the EU and treatment groups revealed significant differences histopathologically and clinically. Conclusion: Experimental uveitis causes an increase in leptin expression in the retina, choroid, sclera and episclera of guinea pigs. Vitamin E, melatonin and aprotinin inhibit this increase. Leptin seems to be closely related to ocular inflammation.Öğe Familial dominant druzenli bir olgu sunumu(2005) Aydemir, Orhan; Yılmaz, Turgut; Çelebi, Serdal; Kükner, A. ŞahapAmaç: Familial dominant druzen (FDD) otozomal dominant genetik geçiş gösteren ve retina pigment epiteli metabolizmasında bozuklukla seyreden bir klinik tablodur. Hastalık, sıklıkla hayatın ikinci ve üçüncü dekadları arasında asemptomatik olarak ortaya çıkmaktadır. Yöntem: Bu çalışmada, FDD tanısı alan bir olgunun klinik bulguları, karakteristik özellikleri ve tanı kriterleri incelendi.Öğe İskemik tip akut santral retina ven tıkanıklığının intravitreal doku plazminojen aktivatörü ile tedavisi(2004) Aydemir, Orhan; Kükner, A. Şahap; Yılmaz, Turgut; Çelebi, Serdal; Ulaş, FatihAmaç: İskemik tip akut santral retina ven tıkanıklığı (SRVT) olgularında intravitreal doku plazminojen aktivatörü (dPA) uygulamasının görme keskinliği üzerindeki etkilerinin araştırılması amaçlanmıştır. Gereç ve Yöntem: İskemik tip akut SRVT tanısı konulan 10 olguya intravitreal 80-100 mg dPA enjeksiyonu yapılarak, hastaların başlangıç, ikinci ve altıncı hafta, üçüncü ve altıncı aylarda görme keskinlikleri, biyomikroskopik muayeneleri ve fundus fluoressein anjiyografileri (FFA) değerlendirildi. Bulgular: 10 hastaya uygulanan intravitreal dPA enjeksiyonu sonrası 4 (%40) hastada görme keskinliği 0,4 ve üzeri seviyelerine ulaştı. 8 olguda (%80) görme keskinliği başlangıç görme keskinliğine göre daha iyi bir seviyedeyken, 2 olguda (%20) görme keskinliği aynı düzeyde kaldı. Retina iskemisinde artış gözlenen 4 (%40) olguya PRFK uygulandı. Komplikasyon olarak sadece 1(%10) hastada kendiliğinden düzelen vitreus hemorajisi izlendi. Sonuç: Akut iskemik SRVT tedavisinde intravitreal dPA enjeksiyonu basit ve güvenilir görünmekle beraber daha geniş hasta gruplarında uzun dönem takip sonuçları ile desteklenmesi gerektiğini düşünmekteyiz.Öğe Leptin in corneas from keratoconus and infectious keratitis patients(Mary Ann Liebert, Inc, 2005) Aydemir, Orhan; Nazıroğlu, Mustafa; Çolakoğlu, Neriman; Yılmaz, Turgut; Kükner, Aysel; Kükner, A. ŞahapPurpose: Leptin is produced primarily by adipose tissue. More recent studies have shown extra sites of leptin production in physiologic and ill human tissues. However, whether leptin originates from human corneas in infectious keratitis and keratoconus is not known. The aim of this study was to demonstrate and quantitate leptin expression in corneas with infectious keratitis and keratoconus and make comparisons to control corneas. Methods: We examined the immunohistochemical staining of leptin in nine corneas surgically excised from patients with infectious keratitis (3 patients), keratoconus (3 patients), and donor corneas (3 patients). Results: The results were analyzed using a semi quantitative scoring system of mild, moderate, and strong. Cells of the infectious keratitis group had the strongest leptin staining intensity, the control group had moderate, and the keratoconus group had mild staining intensity. The more vascular corneas in the infectious keratitis group were also associated with the greatest leptin staining. Conclusions: Our findings indicate that leptin expression was present in all three sources of corneas (infectious keratitis, keratoconus, and normal control). Quantitative scoring would imply it may play a role in infectious keratitis, although further experiments are necessary to establish any causal relationship.Öğe Moderate exercise combined with dietary vitamins C and E counteracts oxidative stress in the kidney and lens of streptozotocin-induced diabetic rat(Verlag Hans Huber, 2005) Kutlu, Mehmet; Nazıroğlu, Mustafa; Şimşek, Halil; Yılmaz, Turgut; Kükner, A. ŞahapOxidative stress has a key role in the pathogenesis of diabetes-induced cataract formation and nephropathy. Daily moderate exercise and vitamins C and E (VCE) supplementation can be beneficial to diabetes due to reducing blood glucose and free radical production. The aim of this study was to analyze the effect of moderate exercise with vitamin VCE on lipid peroxidation (LP) and antioxidative systems in the kidneys and lens of streptozotocin-induced diabetic rats. Forty female Wistar rats were used. They were randomly divided into four groups. The first and second groups were used as control and diabetic groups. The third group was the diabetic-exercise group. VCE-supplemented feed was given to diabetic-exercise rats constituting the fourth group. Animals in the exercised groups were moderately exercised daily on a treadmill for three weeks (five days a week). Diabetes was induced on day zero of exercise. Body weights in the four groups were recorded weekly. Lens and kidney samples were taken from all animals on day 20. Glutathione peroxidase (GSH-Px), reduced glutathion (GSH), vitamin E, and beta-carotene levels in kidney and lens, albumin in plasma, and body weight were significantly lower in the diabetic group than in the control groupo, whereas there was a significant increase in LP of kidney and lens as well as plasma glucose, urea, and creatinine levels in the diabetic group. The decrease in antioxidant enzymes, vitamins, and albumin and the increase in LP and glucose levels in diabetic rats were significantly improved with exercise and VCE supplementation. In the diabetic animals, the decreased beta-carotene and vitamins A levels in kidney did not improve through exercise only, although their levels were increased by exercise plus VCE supplementation. In conclusion, these data demonstrate that lipid peroxidation increases in the lens and kidney of diabetic animals and this could be due to decreases in antioxidant vitamins and enzymes. However, dietary VCE with moderate exercise may strengthen the antioxidant defense system through the reduction of ROS and blood glucose levels. The VCE supplementations with exercise may play a role in preventing the development of diabetic nephropathy and cataract formation in diabetic animals.Öğe Oküler albinizmi ve kanama diyatezi olan Hermansky-Pudlak sendromlu bir olgu(2006) Çelebi, Harika; Çelebi, Serdal; Elkıran, Tamer; Kükner, A. Şahap; Köhle, ÜlküHermansky-Pudlak Sendromu (HPS), tirozinaz-pozitif okülokütanöz albinizm, trombosit disfonksiyonuna bağlı kanama diyatezi ve çeşitli dokularda seroid benzeri madde birikimi ile karakterize otozomal resesif geçişli genetik bir hastalıktır. Kanama diyatezi nedeniyle hematoloji servisine başvuran, bu amaçla trombosit süspansiyonu verilen ve bu esnada bilateral görme kaybı gelişen bir hasta konsülte edildiğinde HPS tanısı konuldu. Amacımız, albinizmli bazı hastalarda akla getirilmediğinde kolayca gözden kaçabilen HPS’nın karakteristik özelliklerini literatür ışığında gözden geçirmektir.Öğe Protective effects of intraperitoneal vitamin c, aprotinin and melatonin administration on retinal edema during experimental uveitis in the guinea pig(Wiley, 2004) Kükner, A. Şahap; Kükner, Aysel; Nazıroğlu, Mustafa; Çolakoğlu, Neriman; Çelebi, Serdal; Yılmaz, Turgut; Aydemir, OrhanA considerable amount of clinical and experimental evidence exists suggesting the involvement of reactive oxygen substances (ROS) in the actiology of uveitis. The activated phagocytic system of polymorphonuclear leucocytes in uveitis is involved in the generation of ROS. In addition to their direct free radical scavenging action, aprotinin, melatonin and vitamin C are known to protect against oedema formation and can preserve plasma membrane fluidity and free radical production. Histological changes in the retina that occur during uveitis are not well explained. The purpose of this study was to determine whether vitamin C, aprotinin and melatonin can protect the retina from damage accompanying experimental uveitis (EU). Thirty adult male guinea pigs were divided into five groups of six animals each. The first group was used as control. The right eyes of groups 2, 3, 4 and 5 received an intravitreal injection of bovine serum albumin for induction of experimental uveitis. At the same time and also on the consecutive third day, groups 3, 4 and 5 received intraperitoneal injections of vitamin C (ascorbic acid, 100 mg kg(-1) body wt), aprotinin (20 000 mg kg(-1) body wt) and melatonin (10 mg kg(-1) body wt), respectively. The animals were killed on the sixth day. The average thickness of the retina and inner plexiform layer for each eye was measured in sagittal section near the optic nerve and expressed in microns. The thickness of the retina and inner plexiform layer in the control group was significantly (p < 0.01) lower than in the group EU as compared with the group EU plus vitamin C, group EU plus aprotinin, group EU plus melatonin (p < 0.05). The thicknesses of the retina and inner plexiform layer in group EU plus vitamin C, group EU plus aprotinin and group EU plus melatonin were significantly (p < 0 01) lower than that in the group EU. The difference in thickness of the retina and inner plexiform layer among the groups 3, 4 and 5 was not significant (p > 0.05). In conclusion, this study demonstrated that oedematous effects of EU on the retina were reduced by the administration of intraperitoneal vitamin C, aprotinin and melatonin, i.e. these antioxidants had significant protective effects on the retina of guinea pigs against oedematous damage in EU. However, the reductive effect of vitamin C on EU was greater than that of aprotinin and melatonin. The intraperitoneal vitamin C, aprotinin and melatonin supplementations may strengthen the antioxidant defence system because of decreased ROS, and these agents may play a role in treating uveitis.
