Biomedical subjects

Cem Evereklioglu

Publications and source records attributed to Cem Evereklioglu.

41 records · Page 3Linked to original sources

PubMedDate not supplied

Current concepts in the etiology and treatment of Behçet disease.

Behçet disease is an idiopathic, multisystem, chronic, and recurrent disease characterized by exacerbations alternating with phases of quiescence, episodic panuveitis, and aggressive non-granulomatous occlusive vasculitis of the arteries and veins of any size with explosive ocular inflammatory attacks that primarily affect the retinal and anterior segment vasculature of the eye. The disease is characterized by endothelial dysfunction and may produce a wide variety of symptoms. In mild cases, orogenital ulcers and skin lesions are the only findings during the entire clinical course, whereas ocular lesions that occur in more than half of the cases, frequently bilateral, can eventually lead to blindness. Pulmonary, gastrointestinal, and central nervous system involvements may sometimes be life-threatening. This review examines the epidemiology, frequency, immunology, and immunohistopathology of Behçet disease with recent theories of several agents, including phosphoantigens, superantigens, heat-shock proteins, and adenosine deaminase. Perspectives on the possible roles of new etiopathological molecules, such as nitric oxide, endothelin, and homocysteine, are presented. Ocular and systemic clinical features, diagnostic criteria, classifications, laboratory, fundus fluorescein angiography, and radiologic imaging are discussed. Differential diagnosis, disease in pregnancy and childhood, and prognosis with regard to Behçet-induced systemic and ocular complications are also evaluated. Traditional and current treatments with topical, paraocular and systemic corticosteroids, colchicine, dapsone, cyclosporine, azathioprine, methotrexate, cyclophosphamide and chlorambucil are summarized and recent insights into the pharmacology and effects of thalidomide, tacrolimus (FK-506), interferon-alpha, anti-TNF-alpha blocking monoclonal autoantibody (infliximab) and soluble TNF receptor (etanercept) are reviewed. Key clinical investigations with the status of ongoing clinical trials aimed at addressing the drug's efficacy, surgical care, and studies that have raised the possibility of new therapeutic uses are also presented. The challenges posed by the drug's teratogenicity and adverse effects are also considered, if present.

Behcet Syndrome↗

PubMedDate not supplied

Aqueous humor adrenomedullin levels differ in patients with different types of glaucoma.

PURPOSE: Adrenomedullin is a multifunctional 52 amino acid large peptide. Recent studies have reported that it is expressed in the iris-ciliary body in the eye and that it decreases intraocular pressure (IOP) by increasing outflow facility via specific adrenomedullin receptors, suggesting a role for this peptide in controlling IOP. In the present study, we aimed to explore clinically the possible involvement of adrenomedullin in the pathophysiology of glaucoma. METHODS: Reverse-phase high-performance liquid chromatography was used to determine the aqueous humor adrenomedullin levels in 41 patients (41 eyes) undergoing elective surgery for a variety of ocular diseases in the Research Hospital of Inönü University Medical Faculty between 1999 and 2000. The ocular diseases of the patients included primary open-angle glaucoma (POAG, n = 16), neovascular glaucoma (NG, n = 11), and cataract (n = 14). The study was an open trial with purposive sampling. Aqueous humor samples were taken by paracentesis. Mann-Whitney U-test was used in the statistical analysis and P <.05 was considered as significant. Results were expressed as mean +/- SE. RESULTS: The mean age and sex distribution between groups were comparable. Mean adrenomedullin levels in patients with POAG (22.3 +/- 0.6 pmol/L) were significantly higher than those in patients with NG (5.6 +/- 0.2, pmol/L; P <.001) and cataract (11.9 +/- 0.5, pmol/L; P <.001). On the other hand, the mean aqueous humor adrenomedullin levels in patients with NG were significantly (P <.001) lower than those in cataract patients. CONCLUSIONS: This first clinical in vivo study on aqueous humor adrenomedullin levels showed that this peptide may be involved in the pathophysiology of glaucoma. Increased aqueous humor adrenomedullin levels in patients with POAG may indicate a compensatory defense response against increased IOP to slow the formation and progression of a vicious cycle. On the other hand, there may be deficient production of the peptide in patients with NG, or adrenomedullin-producing cells may be lost because of very high IOP during the course of the disease. The control of adrenomedullin levels in the eye might be a target that could be considered in the therapeutic strategies for glaucoma. Further studies in this respect are needed.

Adrenomedullin↗

PubMedDate not supplied

Determination of nontoxic concentrations of piperacillin/tazobactam for intravitreal application. An electroretinographic, histopathologic and morphometric analysis.

BACKGROUND: To investigate the highest nontoxic intravitreal dose of piperacillin/tazobactam in rabbits. MATERIAL AND METHODS: Forty New Zealand white albino rabbits were used in this study. The rabbits were divided into four equal groups (10 rabbits in each) and the right eyes were treated with 0.1 ml intravitreal injections of 1,000 microg piperacillin/tazobactam in group 1, 500 microg in group 2, 250 microg in group 3, and 100 microg in group 4. The left eyes served as controls and were injected with 0.1 ml of saline solution. Ganzfeld electroretinogram (ERG) was performed on all eyes before and after 4 weeks of intravitreal injections. Then, the rabbits were killed and the eyes were enucleated for histopathological evaluation of the retina. Retinal sections were evaluated by morphometric analyses on cell counts of ganglion cell layer and thickness of the various retinal layers. RESULTS: Baseline ERGs were similar among the groups (p > 0.05). After 4 weeks of injection, there were a reduction of the b-wave amplitude and extension of the b-wave implicit time in photopic and scotopic ERGs in group 1 and group 2 when compared with controls (for each, p < 0.001). Intravitreal injection of 100 and 250 microg piperacillin/tazobactam did not cause any deterioration of the b-wave of ERGs throughout the follow-up period of 4 weeks (for each, p > 0.05). After morphometric analysis of retinal sections in all groups, there were no statistically significant differences in the mean number of surviving ganglion cells, thickness of the whole retina and the inner plexiform layer compared with controls (p > 0.05). CONCLUSION: 250 microg/0.1 ml piperacillin/tazobactam is the highest nontoxic dose to the normal retinas of adult albino rabbits as intravitreal injection. Piperacillin/tazobactam may be a new, potentially important drug in the treatment of endophthalmitis as it has a broad antimicrobial spectrum.

Animals↗

PubMedDate not supplied

Deep sclerectomy with various implants: an experimental and histopathologic study in a rabbit model.

BACKGROUND AND OBJECTIVE: To investigate the effectiveness of various implants used in experimental deep sclerectomy and to report tissue reactions developed to these implants histopathologically. MATERIALS AND METHODS: Forty eyes of 40 New Zealand white albino rabbits underwent deep sclerectomy with various implants. The rabbits were divided into four groups; each consisted of 10 eyes. Deep sclerectomy was performed using copolymer materials in group 1, silicone materials in group 2 and chromic catgut suture in group 3. No implants were used in the control group (group 4). Clinical and histopathological examinations were performed to investigate the effectiveness of implants. RESULTS: Mean preoperative intraocular pressure (IOP) was 14.4 +/- 1.6 mm Hg in group 1, 14.5 +/- 1.8 mm Hg in group 2, 13.8 +/- 1.5 mm Hg in group 3 and 14.5 +/- 1.2 mm Hg in group 4. The final postoperative IOPs were 10.7 +/- 0.9, 10.6 +/- 0.8, 13.5 +/- 1.0, and 14.5 +/- 1.4 mm Hg, respectively. At 2 months, the decrease in IOPs from baseline and the persistence of the filtering bleb were significantly marked in group 1 and group 2 (p < 0.001). Histopathological evaluation revealed that copolymer and silicone materials formed a smooth and regular intrascleral space. There were no foreign body reaction, tissue destruction or fibrosis in group 1 and group 2, but chromic catgut sutures caused severe fibrosis and inflammatory reaction in group 3. Mean histopathologic score of group 1, group 2, group 3 and group 4 was 0.7 +/- 0.5, 0.8 +/- 0.5, 2.4 +/- 0.6, and 0.1 +/- 0.3, respectively. CONCLUSION: Copolymer or silicone materials may increase the success rate of surgery by maintenance of a large and regular intrascleral space after deep sclerectomy and prevention of collapse of the flap.

Animals↗

PubMedDate not supplied

Decreased central corneal thickness in children with Down syndrome.

PURPOSE: A cross-sectional, masked, case-control study was undertaken to investigate whether central corneal thickness is affected in children with Down syndrome and to focus on its clinical significance. PARTICIPANTS AND METHODS: Twenty-eight children with Down syndrome (15 boys and 13 girls) aged 5 to 15 years and 20 age-matched and gender-matched healthy control subjects (11 boys and 9 girls) from a similar ethnic background were enrolled in the study. Central corneal thickness was measured by ultrasound pachymetry. Only the right eye of each child in each group was included in the statistical analysis. The Mann-Whitney U test was used and a P value of less than .05 was considered significant. RESULTS: The mean ages of the children with Down syndrome (9.28 +/- 3.47 years) and the healthy control subjects (8.75 +/- 3.30 years) were comparable (P > .05). Central corneal thickness values were below 500 microm in 19 (67.8%) of the 28 children with Down syndrome, 4 of which were less than 450 microm. However, all central corneal thickness measurements in the control eyes were more than 500 microm. The mean central corneal thickness in the children with Down syndrome was significantly (P < .001) less (488.39 +/- 39.87 microm) than that in the healthy control subjects (536.25 +/- 20.70 microm). Mean keratometric values were significantly (P < .001) higher in the eyes of the children with Down syndrome (46.35 +/- 1.28 D) than in the eyes of the control subjects (43.32 +/- 1.15 D). CONCLUSIONS: Children with Down syndrome had a decreased central corneal thickness compared with healthy control subjects. Decreased central corneal thickness may give an artificially low intraocular pressure measurement by applanation tonometry. Central corneal thickness must be considered when developing approaches for keratorefractive treatment of patients with Down syndrome.

Adolescent↗