Biomedical subjects

Ayça Yilmaz

Publications and source records attributed to Ayça Yilmaz.

8 recordsLinked to original sources

PubMed2005

Effects of apolipoprotein E genotypes on the development of exfoliation syndrome.

Apolipoprotein E (apo E) is directly involved in the amyloid deposition and fibril formation and is present in many cerebral and systemic amyloidoses immunologically. It is encoded by a polymorphic gene and it has three common alleles-epsilon2, epsilon3, and epsilon4. Exfoliation syndrome (XFS) is characterized by the deposition throughout the body of focal fibrillogranular aggregates in which there have been some reports of amyloid or amyloid-like features. We evaluated the possible association between apo E polymorphism and the occurrence of XFS. Using High Pure PCR Template Preparation Kits, genomic DNAs were extracted from whole blood and apo E polymorphisms were determined by using Lightcycler-Apo E Mutation Detection Kits in 76 patients with XFS and 74 controls. The E2/E2, E2/E3 and E2/E4 genotypes (OR 29.9, 95% CI 3.1-293.7; OR 56.1, 95% CI 12.5-252.7; OR 43.9, 95% CI 7.4-257.6, respectively) and the in2 allele are found to have an increased risk of developing XFS (p=0.0001); whereas the in3 allele was found to be protective (p=0.0001). Apo E polymorphism and the presence of in2 allele are seem to be significantly associated with the development of XFS.

Aged↗

PubMed2005

Effects of caffeic acid phenethyl ester on endotoxin-induced uveitis in rats.

PURPOSE: Caffeic acid phenethyl ester (CAPE) has antimicrobial, anti-inflammatory, antioxidant, immunomodulatory, and carcinostatic properties. In this study, the efficacy of CAPE in endotoxin-induced uveitis (EIU) in rats is investigated. METHODS: EIU was induced by a footpad injection of lipopolysaccharide (LPS). In the treatment group, 10 micromol/kg CAPE was injected intraperitoneally immediately after LPS injection. At 24 hr after LPS injection, the number of infiltrating cells, protein concentration, and levels of myeloperoxidase (MPO) in aqueous humor; malondialdehyde (MDA), MPO, and total antioxidant levels in serum were determined. Eyes were enucleated for histopathologic evaluation, and, counting inflammatory cells in iris-ciliary body (ICB), the efficacy of treatment was determined. RESULTS: CAPE significantly suppressed LPS-induced increase in the number of inflammatory cells (p = 0.0001), protein concentration (p = 0.0001), and MPO levels (p = 0.0001) in aqueous humor as well as MDA (p = 0.001) and MPO (p = 0.0001) levels in serum. Histopathologic evaluation of ICB showed significant reduction in the inflammatory cell counts in the treatment group (p = 0.0001). CONCLUSIONS: CAPE was found efficient in suppressing inflammation and ocular tissue damage induced by LPS in rats.

Animals↗

PubMed2005

Is GST gene polymorphism a risk factor in developing exfoliation syndrome?

PURPOSE: To evaluate the distribution of GSTM1, GSTP1, and GSTT1 gene polymorphisms in exfoliation syndrome (XFS) and the possible associations between the presence of exfoliation syndrome and glutathione S-transferase (GST) gene polymorphisms. METHODS: Using a real-time polymerase chain reaction, GSTM1, GSTP1, and GSTT1 gene polymorphisms were detected in 60 patients with exfoliation syndrome, among which 71.7% had exfoliative glaucoma (43 patients), 16.7% had XFS with elevated intraocular pressure (IOP) (10 patients), and 11.7% had XFS only (7 cases), and in 65 otherwise healthy control group of similar age. RESULTS: Although the exfoliation syndrome group presented a higher prevalence of the GSTM1 null and GSTP1 Ile/Val genotypes than the control group, this increase was not statistically significant. GSTT1 null and GSTP1 Val/Val polymorphisms were also not different among groups. The risk of exfoliation syndrome was not increased as the number of putative high-risk genotypes increase (p = 0.73). CONCLUSIONS: GSTM1, GSTP1, and GSTT1 gene polymorphisms were not different among exfoliation syndrome patients, with or without glaucoma, and the controls therefore GSTM1, GSTP1, and GSTT1 gene polymorphisms did not seem to be associated with the risk of development of exfoliation syndrome.

Aged↗

PubMed2005

N-acetyltransferase 2 phenotype may be associated with susceptibility to age-related cataract.

Free radicals and oxidative damage play roles in aging and age-related ocular diseases such as cataracts, so defensive mechanisms become important factors for protection. Because N-acetylation is involved in a wide variety of detoxification processes, this study was conducted to examine the relationship between the acetylator phenotypes and genotypes in a group of patients with age-related cataract. Sixty-one cases of age-related cataract and 104 controls were included in this study. Blood was collected in EDTA-containing tubes, and genomic DNA was extracted from the white blood cells by high pure PCR template preparation kit. Genotyping of NAT2 polymorphisms were detected by using a LightCycler-NAT2 mutation detection kit in real-time PCR. There was a significant difference in the distribution of the NAT2*6A acetylator phenotype between cases and the controls. The odds ratio of cataract for the NAT2*6A slow phenotype was 3.8 (95% CI = 1.08 to 13.11, p = 0.032) compared with the fast type. Our results suggest that slow acetylators are at higher risk of developing age-related cataracts than fast acetylators. As NAT2 is an important xenobiotic-metabolizing enzyme and theoretically xenobiotics such as ultraviolet B radiation, smoking, and alcohol use may induce cataract formation, NAT2 gene polymorphisms may be associated with genetic susceptibility of cataract.

Acetylation↗

PubMed2005

Cranial optic nerve involvements in patients with severe COPD.

OBJECTIVE: The relationship between neuropathy and increased morbidity in patients with COPD is clear, but few studies have assessed cranial neuropathies, especially optic nerve involvement, in COPD patients. We evaluated peripheral involvement of the optic nerve and determined factors influencing this condition in patients with severe COPD. METHODOLOGY: Twenty-eight patients, mean age 59.4 +/- 9.4 years, diagnosed with severe stable COPD according to the GOLD criteria, and 20 age- and gender-matched healthy individuals, mean age 55.6 +/- 8.5 years, were included in the study. All subjects underwent visual evoked potential (VEP) assessment together with detailed clinical and laboratory examination to exclude concurrent risk factors for neuropathy. RESULTS: VEP assessment showed significant abnormalities in COPD patients (82.1%) (commonly amplitude abnormalities) when compared with healthy controls. CONCLUSIONS: The optic nerve is often involved in patients with severe COPD, possibly as part of a polyneuropathy, and this is related to acidosis, hypercarbia and airway obstruction, independent of disease duration, smoking and age. These results should be taken into consideration when determining management strategies for these patients.

Case-Control Studies↗

PubMed2004

May glutathione S-transferase M1 positive genotype afford protection against primary open-angle glaucoma?

PURPOSE: To find out whether the polymorphism at GSTM1, GSTT1 and GSTP1 loci is associated with increased susceptibility to glaucoma. METHODS: We genotyped 153 primary open angle patients and 159 healthy controls. Genomic DNA from peripheral blood was examined using polymerase chain reaction and defined for the genetic polymorphisms of glutathione S-transferase. RESULTS: The frequency of the GSTM1 null genotype individuals among the glaucoma patients was significanlty higher than in controls (54.9 vs 40.9%) with odds ratio of 1.64 (95% CI: 1.10-2.59). The frequency of the GSTT1 and GSTP1 in both groups were not statistically different. CONCLUSION: The present study suggests that the GSTM1 null genotype may be a genetic risk factor for development of primary open angle glaucoma. Further associations studies in other polymorphic genes for xenobiotic-metabolizing enzymes are needed to elucidate the environmental-genetic interaction in the underlying cause of primary open angle glaucoma.

Adult↗

PubMed2003

Traumatic subconjunctival crystalline lens dislocation.

PURPOSE: To evaluate the clinical features and visual outcomes in patients with traumatic subconjunctival crystalline lens dislocation. SETTING: Izmir Atatürk Education and Research Hospital, Department of Ophthalmology, Izmir, Turkey. METHODS: The clinical records of 5 patients with subconjunctival crystalline lens dislocation secondary to blunt trauma were reviewed. RESULTS: The median age of 3 women and 2 men was 63 years (range 62 to 73 years). The lenses were dislocated to the superior (n = 1), temporal (n = 1), superotemporal (n = 1), and superonasal (n = 2) quadrants. All patients had various degrees of hyphema and vitreous hemorrhage. One patient had traumatic optic neuropathy. Visual acuity improved in all patients after lens removal and scleral rupture repair. CONCLUSION: With timely intervention, the visual outcome was reasonably good in patients with subconjunctival dislocation of the crystalline lens.

Aged↗

PubMedDate not supplied

Effect of caffeic acid phenethyl ester on treatment of experimentally induced methicillin-resistant Staphylococcus epidermidis endophthalmitis in a rabbit model.

This study investigated the anti-inflammatory effects of caffeic acid phenethyl ester (CAPE), a natural bee-produced compound, and compared it with corticosteroids in the treatment of experimentally induced methicillin-resistant Staphylococcus epidermidis (MRSE) endophthalmitis in addition to intravitreal antibiotics. An experimental endophthalmitis model was produced in 24 New Zealand albino rabbits by unilateral intravitreal injection of 0.1 ml of 4.7 x 10(4) colony-forming units (CFU) methicillin-resistant S. epidermidis. The animals were then divided randomly into three treatment groups and a control group, group 1 (six rabbits), received only intravitreal vancomycin (1.0 mg/0.1 ml); group 2 (six rabbits), received both intravitreal vancomycin (1.0 mg/0.1 ml) and intravitreal dexamethasone (400 microg/0.1 ml) and group 3 (six rabbits), received both intravitreal vancomycin (1.0 mg/0.1 ml) and subtenon CAPE (10 mg/0.3 ml) after 24 h post-infection. No treatment was given to the control group. Treatment efficacy was assessed by clinical examination, vitreous culture and histopathology. There were no statististically significant differences between clinical scores of all groups in examinations at 24 and 48 h post-infection (p = 0.915 and p = 0.067 respectively), but in examinations at 72 h post-infection and after 7 days post-infection, although the clinical scores of treatment groups were not significantly different from each other, they were significantly lower than the control group (p < 0.05). The culture results of all groups were sterile. As a result, CAPE was found to be as effective as dexamethasone in reducing inflammation in the treatment of experimental MRSE endophthalmitis when used with antibiotics. More studies are needed to determine the optimal administration route and effective dosage of this compound.

Analysis of Variance↗