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Öğe Analysis of Tears in Patients with Atopic Keratoconjunctivitis, Using Flow Cytometry(KARGER, 1998) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Tekelioğlu, YavuzAtopic keratoconjunctivitis (AKC) is a chronic allergic eye disease, Although the pathogenesis is not fully understood, some impairment in cell-mediated immunity was suggested by histopathological findings in conjunctival specimens obtained from affected individuals. T-cell infiltration and an enhanced T-helper/T-suppressor cell ratio in conjunctival biopsy specimens were observed previously by immunofluorescence procedures, We analyzed the cells in tears of patients with AKC using flow cytometry (FCM) and compared the results to those of normal subjects to identify the role of T lymphocytes in the pathogenesis of the disease, The tear samples of the patients and normal subjects were collected with capillary tubes, and the surface receptors of cells were detected with FCM. Statistical analyses were performed with Student's t test, The percentages of T cells, activated B cells, and T-helper/T-suppressor cell ratios were found to be higher in the tears of patients with AKC than in controls, We propose that a decreased T-suppressor cell concentration in tears may enhance immunoglobulin-E production of B cells, and the signs and symptoms are provoked by inflammatory mediators liberated from mast cell degranulation.Öğe CD4+ T Cell/CD8+ T Cell Ratio in the Anterior Chamber of the Eye After Penetrating Injury and Its Comparison with Normal Aqueous Samples(ELSEVIER SCIENCE INC, 1998) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Tekelioğlu, Yavuz; Kapıcıoğlu, ZerrinWe have recently reported that significantly more CD8(+) T-cell activity is present in the aqueous humor compared to peripheral blood. The aim of the current study is to investigate the effect of the ocular trauma on the number of the T lymphocyte subsets in the aqueous humor. CD4(+)/CD8(+) T-cell ratios in the aqueous and blood samples of 12 patients who suffered from traumatic iridocyclitis because of a corneal perforation were compared to those of patients with senile cataracts. We found a relatively higher CD4(+)/CD8(+) cell ratio in the aqueous samples of traumatized patients than cataractous patients. Meanwhile, no difference was present between the aqueous and blood samples of the traumatized patients with respect to the above-mentioned ratio. We suggest that one of the most important factors in maintaining a lower CD4(+)/CD8(+) cell ratio in normal aqueous humor compared to peripheral blood is an intact blood-aqueous barrier. Blood-aqueous barrier may play a participating role in the pathogenesis of immunosuppressive properties of the anterior chamber of the eye by establishing higher CD8(+) T-cell activity in the aqueous humor relative to the peripheral blood.Öğe Characterization of T Lymphocyte Subtypes in Endotoxin-İnduced Uveitis and Effect of Pentoxifylline Treatment(Swets Zeitlinger Publishers, 2002) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Öztekin, Esma; Baltacı, Abdulkerim KasımPurpose. The aims of the study were twofold: 1) to investigate the role of T lymphocyte subtypes in the pathogenesis of endotoxin-induced uveitis (EIU) and 2) to study the possible beneficial effect of pentoxifylline, an inhibitor of neutrophil motility, and Tumor Necrosis Factora-alpha on this disease. Methods. Forty-two inbred male Lewis rats were divided into seven equal groups. 200 m g of Escherichia coli 055: B55 lipopolysaccharide (LPS) was injected in one hind footpad of the Group 2, 3, 4, 5, 6, and 7 rats. Group 5, 6, and 7 rats also received concomitant intraperitoneal pentoxifylline (PTX) during food pad injection of LPS. Group 1 rats were used as controls with intra-peritoneal normal saline injection. Eight, 24, and 48 hours after treatment, the rats were euthanized. Neutrophil leukocyte, mononuclear cells, and CD4+, CD8+, and CD45RA+ cell infiltration in the anterior uveal tissue were determined either by hematoxylin-eosin or monoclonal antibody staining. Tumor Necrosis Factor-alpha (TNF-alpha) levels were also measured in the aqueous and blood samples. We compared the numbers of infiltrating cells in the different groups. Results. We found that peak infiltration of lymphocyte, neutrophils, and CD4+ cells occurred at 24 hours. However, CD8+ and CD45RA+ cell number reached their highest levels at 48 hours. There was no inflammatory cell infiltration in the control rats. Concomitant pentoxifylline treatment did not affect any of these parameters, although it effectively reduced TNF-alpha concentrations in the anterior chamber and the serum. Conclusion. We conclude that, 1) T lymphocytes might be involved in the pathogenesis of endotoxin-induced uveitis. 2) The potential role of pentoxifylline in the treatment of human uveitis is questionable. However, these are initial findings and need confirmation by additional studies.Öğe The Comparison of Efficacies of Topical Corticosteroids and Nonsteroidal Anti-inflammatory Drops on Dry Eye Patients: a Clinical and Immunocytochemical Study(Elsevier Science Inc, 2003) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Varnell, E. D.; Kaufman, H. E.PURPOSE: To investigate whether conjunctival inflammation represents a primary event in the pathogenesis of keratoconjunctivitis sicca or whether it is a secondary inflammatory reaction caused by enhanced mechanical irritation as a result of surface dryness and whether anti-inflammatory drops (corticosteroids and nonsteroidal anti-inflammatory) have therapeutic effects and are similar. DESIGN: Single-masked, randomized, prospective clinical trial. METHODS: Thirty-two keratoconjuctivitis patients with or without Sjogren syndrome were included in the study. The patients were randomized to three groups. Group I patients received a topical artificial tear substitute (ATS); group 2 received ATS plus nonsteroidal anti-inflammatory drops (NSAID); and group 3 received ATS plus topical corticosteroidal drops. The eye symptom severity scores, Schirmer test values, rose bengal and fluorescein staining scores were evaluated before treatment and 15 and 30 days after start of treatment. Impression cytology specimens were stained using immunohistochemical methods to detect the percentages of human leukocyte antigen II (HLA-DR) positive, Apo 2.7 positive, and periodic acid-Schiff positive cells. Statistical analyses were performed within and between groups. RESULTS: Group 3 patients had significantly lower symptom severity scores, fluorescein and rose bengal staining, and HLA-DR positive cells on days 15 and 30 compared with patients in other groups. They also had a significantly higher number of periodic acid-Schiff positive (goblet) cells in their impression cytology specimens on days 15 and 30 compared with the other patients. On day 30, group 3 patients had significant differences compared with their baseline measurements in terms of above,mentioned parameters. However, we did not detect a significant effect of any treatment schedule on the Shirmer test value and the numbers of Apo 2.7 cells in impression cytology specimens. CONCLUSIONS: Topical corticosteroids had a clearly beneficial effect both on the subjective and objective clinical parameters of moderate-to,severe dry eye patients. These effects were associated with the reduction of inflammation markers of conjunctival epithelial cells. (C) 2003 by Elsevier Inc. All rights reserved.Öğe Cyclosporine Effects on Clinical Findings and Impression Cytology Specimens in Severe Vernal Keratoconjunctivitis(KARGER, 2001) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Erdöl, Hidayet; Kapıcıoğlu, Zerrin; Akyol, NurettinPurpose: To investigate the possible effects of topical cyclosporine eye drops 2% (CsA) on conjunctival immune cells obtained by impression cytology technique and to determine the clinical relevance of this effect if present. Methods: Ten consecutive patients with severe, resistant, and active vernal keratoconjunctivitis (VKC) were included in this study. All of them were treated with 2% of topical CsA drops. Symptom and clinical scores and conjunctival impression cytology specimens were obtained both before and following treatment. Impression cytology specimens were stained with anti-CD8+, CD4+, CD45RA+, and CD23+ antibodies and the percentages of positive cells were counted. The results were compared and correlation analyses were performed between clinical and laboratory data. Results: Significant reductions were observed with respect to the percentages of CD4+ and CD23+ cells in the conjunctival impression cytology specimens and clinical and symptom scores following treatment with topical CsA, while no change occurred in the percentages of CD8+ and CD45RA+ cells. The percentages of CD4+ and CD23+ cells showed good correlations with symptom and clinical scores. Conclusion: Topical CsA treatment is a very effective alternative in severe VKC cases in clinical ground and clinical efficacy of topical CsA treatment in severe, resistant VKC cases can be (at least partly) related to reduction of the CD23+ and CD4+ cell populations on the conjunctival surface.Öğe Effect of melatonin and zinc on the immune response in experimental toxoplasma retinochoroiditis(KARGER, 2007) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Baltaci, Abduelkerim Kasim; Mogulkoc, RasimObjectives: To investigate the possible effect of melatonin (MEL) and zinc on the immune response to Toxoplasma gondii retinochoroiditis in the rat model of infection and to establish the possible value of artificial MEL and/or zinc supplementation as adjunctive therapeutic agents in the treatment of T. gondii retinochoroiditis. Methods: Eighty-four Sprague-Dawley male rats were divided into 12 equal groups. All groups, except controls were infected with T. gondii parasite by intraperitoneal injection. Combinations of zinc-deficient diet, pinealectomy (Px), and artificial zinc and MEL were supplied during a 1-month period. At the end of the experiment, retinal and choroidal total lymphocytes, CD3+, CD4+, and CD8+ cell numbers were counted in histological sections. Results: The highest amount of cellular infiltration (lymphocytes, CD3+, CD4+, CD8+ cells) in the choroid and retina was detected in infected + MEL + zinc-treated rats, and the least amount of cellular infiltration was observed in Px + zinc-deficient diet-treated rats. Although single zinc or MEL supplementation had no significant impact on the cellular infiltration in the retina and choroid in Px rats, combined therapy significantly improved these responses. Conclusion: Artificial supplementation of MEL and zinc should be considered as an adjunctive therapy to classic treatment of Toxoplasma retinochoroiditis especially in immunosuppressed and elderly patients if our data are confirmed in a clinical setting.Öğe A Flow Cytometric Study About the Immunopathology of Vernal Keratoconjunctivitis(MOSBY-ELSEVIER, 1998) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Dayanır, Volkan; Tekelioğlu, Yavuz; Dayıoğlu, Yavuz SelimBackground: Vernal keratoconjunctivitis (VKC) is a bilateral seasonal conjunctival inflammation. Exact pathogenesis of the disease is unknown, but some evidences suggest T-H lymphocyte-mediated immune reactions. Objective: The aim of this study was to investigate the role of the T lymphocyte and its subsets in the pathogenesis of VKC. Methods: We obtained tear samples from patients with VKC and normal volunteers during active (spring) and quiescent (winter) periods, The patients' records were also obtained for assessment of symptom scores, The percentages of CD4/29+, CD4/45RA+, CD4+, and CD8+ in tear samples were established by using Bow cytometry, and the results of all three groups were compared with each other by using the Wilcoxon matched-pair signed-rank test and the Mann-Whitney U test. Results: The percentages of CD4/29+ and CD-If cells in tears of patients with VKC increased significantly in the active period and decreased to normal levels in the quiescent stage. In contrast, the percentages of CD4/45RA+ and CD8+ cells in tears of patients with VKC did not show any significant change between spring and winter, The patients' symptoms were significantly lower in the quiescent period (winter) compared with the active stage (spring). Conclusion: We propose that increased numbers of CD-IC and CD4/29+ cells in tears may be exacerbating the disease during the spring season.Öğe Further Studies on the Immunopathology of Atopic Keratoconjunctivitis Using Flow Cytometry(ACADEMIC PRESS LTD, 1997) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Dayanır, Volkan; Tekelioğlu, YavuzAtopic keratoconjunctivitis (AKC) is an ocular manifestation of systemic hypersensitivity. Although the pathogenesis of AKC is not fully understood, some previous data suggest that a decrease in numbers of suppressor T lymphocyte (Ts) and increase of Th, especially Th2 (the second subgroup of helper T lymphocyte), at the ocular surface may play an important role in the occurrence of the disease. In this study, the percentages of naive-Th (CD4/45RA +) and memory-Th (CD4/29 +) cells, and the Th/Ts and memory-Th cells/naive-Th cells ratios were measured in the blood and tear samples of patients with AKC, atopic patients without ocular involvement and normal volunteers, using flow cytometry. Groups were compared using the Mann-Whitney U test. We found that patients with AKC had significantly higher memory-Th cell concentration, and Th/Ts and memory-Th cells/naive-Th cell ratios both in the tear and blood samples compared to normal subjects. While no significant difference existed between the tear samples of the atopic patients without ocular involvement and normal volunteers with respect to the above values, atopic patients had higher percentages of memory-Th cells and higher Th/Ts and memory-TH cells/naive-Th ratios in their blood than normal subjects. The percentages of memory-Th cells, and the Th/Ts and memory-Th cells/naive-Th cell ratios in the tear samples of AKC patients were also found to be higher than that of the atopic patients without ocular involvement, but no significant difference was present between the blood samples of these groups. The percentages of naive-Th cells did not show any significant difference between groups either in tear or blood samples. Since the mean memory-Th cells/naive-Th1 cells ratio in the tear samples of the patients with AKC was higher than in their blood samples, we propose that the localized accumulation of memory-Th2 cells, in addition to the increase of Th/Ts ratios in the external eye may cause AKC in atopic individuals.Öğe Immunohistochemical analysis of orbital connective tissue specimens of patients with active graves ophthalmopathy(TAYLOR & FRANCIS INC, 2005) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Pazarlı, Halit; Oğuz, Velittin; Varnell, Emily D.; Kaufman, Herbert E.; Aksoy, FigenPurpose: To explore the immune mechanism of Graves ophthalmopathy (GO) by analyzing infiltrating cells in orbital connective tissue (OCT) specimens of patients with active GO using immunohistochemical methods. Methods: Five OCT specimens obtained from patients with active GO and five control specimens obtained from forensic cadavers who died from nonmedical reasons were stained with anti-CD3, CD4, CD8, CD45RO, HLA-Dr, CD25, and TNF-alpha monoclonal antibodies. Positively stained cells were counted and results were interpreted as cell counts/mm(2). Four of five GO patients had never been treated with any immunomodulating therapy. Only one had received oral prednisolone prior to tissue sampling, but this treatment had ceased 5 months before surgery. Results: The retro-orbital tissue specimens obtained from forensic cadavers did not show any significant positive staining for any monoclonal antibody tested. However, the specimens from GO patients showed positively stained means of 36.66 +/- 4.61 HLA- Dr(+), 12.8 +/- 3.42 CD8(+), 11.8 +/- 1.78 CD4(+), 16.6 +/- 1.81 CD3(+), 21.2 +/- 3.12 CD45RO(+), 10.4 +/- 2.07 TNF-alpha(+), 7.2 +/- 1.48 CD25(+), 3.2 +/- 1.09 CD4(+) CD8(+), 4.6 +/- 1.67 CD4(+) CD45RO(+), 2.8 +/- 0.83 CD8(+) CD45RO(+), 1.6 +/- 0.89 CD4(+) CD25(+), and 1.8 +/- 1 0.83 CD8(+) CD25(+) cells/ mm(2). Conclusions: Our study supports that most of the infiltrating lymphocytic cells in the active stage of GO are T cells, and a significant proportion of them are CD45RO+ cells. Infiltration of OCT by HLA- Dr+, CD25+, and TNF-alpha cells suggests that Th1-type immune reaction with the interference of proinflammatory cytokine(s) (TNF-alpha) may be important in the pathogenesis of disease. Further studies are needed to understand the disease pathogenesis and may provide a scientific basis for future treatment alternatives for the disease (e. g., anticytokine treatment).Öğe Mechanisms and Comparison of Anti-allergic Efficacy of Topical Lodoxamide and Cromolyn Sodium Treatment in Vernal Keratoconjunctivitis(Elsevier Science Inc, 2000) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Kapıcıoğlu, Zerrin; Akyol, Nurettin; Tavlı, LemaPurpose: To explore the mechanism of action of topical lodoxamide and cromolyn sodium treatment in vernal keratoconjunctivitis (VKC) and to compare the efficacy of these drugs to each other. Design: Single-investigator, masked, randomized, clinical trial. Participants: Twenty male and 10 female patients between the ages of 6 and 19 years, who were diagnosed as having active VKC, were enrolled in this study. Interventions: The patients were randomly divided into two equal groups (groups A and B). Group A patients received topical lodoxamide ophthalmic solution 0.1% (LOS); topical cromolyn sodium ophthalmic solution 4% (CSO) was prescribed to group B patients in a dose of two drops four times daily. Main Outcome Measures: The eye symptom severity scores and clinical signs of the patients were evaluated both in the pre- and post-treatment periods. In addition to the clinical data, conjunctival impression cytologic specimens were obtained from patients both before and after treatment. Impression cytologic specimens were stained using immunohistochemical methods to detect the percentages of CD4(+), CD8(+), CD45RA(+), and CD23(+) cells. Statistical analyses were performed within and between groups. Results: The percentages of CD4(+) and CD23(+) cells in tear samples of patients in groups A and B were significantly higher in the pretreatment stage than post-treatment stage. In the post-treatment stage, group A patients had significantly lower CD4(+) and CD23(+) cell values compared with group B patients. Patient symptom scores and clinical signs were at a significantly lower level after treatment with either LOS or CSO in both groups A and B compared with their pretreatment values. Moreover, group A patients had significantly lower symptom scores and clinical signs than group B patients in the post-treatment stage. Conclusions: Clinical superiority of LOS over CSO may be linked to its greater effect on the CD4(+) cells, because CD4(+) cells plays a pivotal role in the pathogenesis of VKC.Öğe Pharmacological Mechanism of Topical Lodoxamide Treatment in Vernal Keratoconjunctivitis: a Flow-Cytometric Study(KARGER, 1998) Avunduk, Avni Murat; Avunduk, Mustafa Cihat; Dayanır, Volkan; Tekelioğlu, Yavuz; Dayıoğlu, Yavuz SelimThe aim of this study was to investigate the possible effect of lodoxamide 0.1% ophthalmic solution (LOS) on tear T lymphocytes, especially Th2 (T helper 2 subgroup of helper T lymphocytes), in the tear specimens of patients with vernal keratoconjunctivitis (VKC) and to explore the mechanism of the anti-allergic effect of this drug. Twenty-eight active VKC patients were randomly divided into two groups each containing 14 patients. We obtained tear samples from all patients at the beginning of the study. LOS was prescribed to the study group (group A), but the controls (group B) received placebo over the course of 6 weeks. Tear samples were also collected from all patients following a 6-week course of treatment with either LOS or placebo. The percentages of Th1, Th2 and Th cells in the tear samples were measured by using a flow-cytometric technique and the results were compared to each other by using Wilcoxon matched-pairs signed-rank and Mann-Whitney U tests. We found that LOS treatment decreased the percentages of Th2 and Th cells in the tears of group A patients, while placebo had no effect on these values, Th1 cell count in the tears of both groups of patients did not show any significant change between the pre-and posttreatment stages, Our data suggest that LOS exerts, at least, some part of its anti-allergic effect via decreasing the Th2 cell number in the tears of VKC patients.Öğe A Possible Mechanism of X-Ray-İnduced Injury in Rat Lens(Springer Tokyo, 2000) Avunduk, Avni Murat; Yardımcı, Serdar; Avunduk, Mustafa Cihat; Kurnaz, Levent; Cengiz, MustafaPurpose: X-ray and other radiation can cause cataract, but the pathogenic mechanism is largely unknown. The aim of this study was to investigate the accumulation of iron in the x-ray-exposed rat lens and its relationship to lens injury. Methods: Fifty male Wistar rats were divided randomly into five groups of 10. Groups 2 and 4 rats were sham-exposed, groups 3 and 5 were x-ray-treated, and group 1 served as control. X-ray radiation and sham exposure were performed in a similar manner. After 10 and 30 days of exposure, a lens from each rat in groups 2 and 3, and 3 and 5, respectively, were analyzed by flame atomic absorption technique for the assessment of metal content. Results: Significantly decreased zinc and increased iron and calcium concentrations were detected in the lens samples of groups 3 and 5 compared with groups 2 and 4 and controls. Similar results were obtained comparing groups 5 and 3. Conclusions: We propose that x-ray exposure may cause toxic cell injury of the rat lens via Fenton metals catalyzed damage. initial lens membrane damage in the radiolytic phase may permit the access of iron resulting in lens damage.
