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Biomedical subjects

C Güler

Publications and source records attributed to C Güler.

At least 19 recordsLinked to original sources
PubMed2001

Prevention of posterior capsule opacification by retinoic acid and mitomycin.

BACKGROUND: Our aim was to evaluate the effect of an intraoperative single dose of retinoic acid (RA) or mitomycin C (MMC) in preventing posterior capsule opacification (PCO). METHODS: Twenty-seven rabbits were divided randomly into three groups. RA (250 microg/ml) and MMC (0.04 mg/ml) were given 0.1 ml by hydrosection and 0.9 ml into the capsular bag after phacoemulsification. The third group served as a control group. Three months after intervention PCO was graded clinically. Furthermore, proliferation of lens epithelial cells was evaluated histologically. RESULTS: Two eyes developed corneal edema in the MMC group. On clinical assessment, RA and MMC were significantly effective in preventing PCO compared with controls (P<0.005). On histological analysis, there was significantly reduced proliferative activity on posterior capsules in the treatment groups, in contrast to multilayer cells in the control group. CONCLUSION: Intraoperative single-dose administration of RA and MMC significantly prevented the development of PCO in rabbit eyes. The optimal biocompatible dosage must be carefully determined by further investigation.

Animals↗
PubMed2001

Prevention of posterior capsule opacification by intraoperative single-dose pharmacologic agents.

PURPOSE: To determine whether an intraoperative single dose of dexamethasone, diclofenac, ethylenediaminetetraacetic acid (EDTA), a combination of EDTA and RGD peptide (arginine-glycin-aspartic acid sequence), or mitomycin-C (MMC) is a pharmacological means of preventing or reducing the development of posterior capsule opacification (PCO). SETTING: Department of Ophthalmology, Celal Bayar University, School of Medicine, Manisa, and Department of Pathology, Dokur Eylül University, School of Medicine, Izmir, Turkey. METHODS: Fifty-four rabbits were randomly divided into 6 groups. Dexamethasone (4 mg/cc), diclofenac (2.5 mg/cc), EDTA (8 mg/cc), a combination of EDTA and RGD peptide (2.5 mg/cc), or MMC (0.04 mg/cc) was given, 0.1 cc by hydrodissection and 0.9 cc into the capsular bag after phacoemulsification. The sixth group served as a control group. After 3 months, the PCO was graded clinically and the proliferation of lens epithelial cells (LECs) was evaluated histologically. RESULTS: The drugs were significantly effective in preventing PCO compared with the control (P <.005). Dexamethasone had a weaker effect than the other drugs. In histological analysis, although monolayer LECs in the dexamethasone and diclofenac groups were observed, there was no proliferative activity on the posterior capsules in the EDTA, EDTA+RGD, and MMC groups in contrast to the multilayer cells in the control. CONCLUSIONS: Intraoperative single-dose application of EDTA, EDTA+RGD peptide combination, and MMC significantly prevented the development of PCO in rabbit eyes. Diclofenac was less effective but also reduced PCO. Although dexamethasone did not prevent the proliferation of LECs, it decreased PCO clinically.

Animals↗
PubMed2001

Significance of tissue laminin P(1) elastase and fibronectin levels in transitional cell carcinoma of the bladder.

OBJECTIVE: Elastase is a serine protease which hydrolyses connective tissue components. Laminin and fibronectin also play an important role in progression and invasion of cancer. The purpose of this study is to investigate the relation between tissue elastase, laminin P(1) and fibronectin levels and tumor characteristics, and analyze the potential of these as prognostic factors in transitional cell carcinoma (TCC) of the bladder. METHODS: Thirty-four patients with TCC of the bladder and 11 controls were included in this study. Elastase and fibronectin levels in tissue homogenates were determined using an enzyme immunoassay and laminin P(1) by radioimmunoassay. Mean follow-up was 43 months. RESULTS: The mean elastase level in bladder carcinoma tissue was 120+/-11.42 ng/homogenate protein, while normal tissue level was 12.36+/-2.70 (p<0.01). The carcinoma and normal tissue mean laminin P(1) levels were 7.02+/-0.37 U and 0.65+/-0.10 U/mg homogenate protein, respectively (p<0.01). The mean fibronectin level was 19.97+/-1.45 ng/mg homogenate protein in the carcinoma tissue and 2.16+/-0.40 in normal tissue (p<0.01). There was no correlation between tumor stage, grade, size, multiplicity and elastase, laminin P(1) and fibronectin levels. CONCLUSION: These results provide evidence that tissue elastase, laminin P(1) and fibronectin levels increase in TCC of the human bladder. Further studies including serum and urine levels should be performed in order to analyze their value as tumor markers in a larger group of patients.

Adult↗
PubMed2000

Adverse effects of topical antiglaucoma drugs on the ocular surface.

PURPOSE: This study was designed to determine the effect of long-term antiglaucoma topical medication on the ocular surface; measuring basal Schirmer's and tear break-up time tests using conjunctival impression cytology. METHODS: The ocular surfaces of 30 control subjects (group 1), 24 primary open-angle glaucoma patients treated with 0.5% betaxolol hydrochloride (group 2), 27 primary open-angle glaucoma patients treated with 0.5% timolol maleate (group 3) and 26 primary open-angle glaucoma patients treated with 0.5% betaxolol and 1% dipivefrin hydrochloride (group 4) were evaluated. Basal Schirmer's and tear break-up time tests were measured and ocular surface changes were determined by impression cytology. Impression cytology specimens of each group were graded and scored in the range 0-3 according to Nelson's method. RESULTS: Patients in groups 2, 3 and 4 showed statistically significant fewer normal basal Schirmer's tests (wettability) and tear break-up time tests (P < 0.01). Also, the conjunctival impression cytology scores were significantly higher in groups 2, 3 and 4 than in group 1 (P < 0.01). CONCLUSIONS: The conclusion was that it is possible that conjunctival surface and tear film function change after the long-term use of antiglaucoma medication.

Adrenergic beta-Antagonists↗
PubMed2000

Ocular findings in a measles epidemic among young adults.

PURPOSE: To present ocular findings in a measles epidemic outbreak among young adults. METHODS: Ophthalmic lesions in an unselected group of 61 young military personnel with measles were followed. Eighteen of the patients had symmetric keratitis in both eyes. They were treated with diclofenac sodium eyedrops qid in the right eye, while the left eye was observed untreated. The disappearance of the corneal lesions in both eyes was compared. RESULTS: Forty patients (65.6%) had measles conjunctivitis with bulbar and tarsal conjunctival hyperemia. Five (8.2%) had increased mucous secretion. Thirty-five (57.4%) had superficial punctate corneal epithelial and subepithelial lesions which stained with fluorescein. Ten patients had corneal lesions without evident conjunctival pathology. Fourteen patients had subconjunctival hemorrhages, 12 of whom had bilateral lesions mostly in the superonasal quadrant. The time to disappearance of corneal lesions was 4.5+/-3.2 days in the diclophenac-treated right eyes, and 4.1+/-3.8 days in the left eyes. We did not observe a significant difference in the healing time between the two eyes (p = 0.75). CONCLUSION: Measles did not cause major ocular complications in healthy patients. Keratitis was unresponsive to diclophenac sodium eyedrops with respect to healing time and end result.

Adult↗
PubMed2000

Religious fasting and intraocular pressure.

PURPOSE: To determine the effects of Islamic religious fasting on intraocular pressure. METHODS: The authors measured diurnal intraocular pressure values during religious fasting and 1 month later in 38 healthy male volunteers with a mean age of 22.4 +/- 2.7 years. Body weight and urine specific gravity were determined to assess the extent of dehydration caused by fasting. RESULTS: Although each patient had weight loss (0.1-1.4 kg) representing a slight dehydration caused by fasting, intraocular pressure values were not statistically different between fasting and nonfasting periods (P > 0.05). CONCLUSION: Fasting did not alter diurnal intraocular pressure values in healthy people.

Adult↗
PubMed2000

Extracapsular cataract extraction with posterior chamber lens implantation in capsular glaucoma.

PURPOSE: To evaluate intraocular pressure (IOP) control after extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens (PCIOL) implantation in patients with capsular glaucoma (CG) and coexisting cataract. METHODS: This prospective study included 20 patients (20 eyes) having CG and cataract whose IOPs were under 22 mm Hg and controlled with antiglaucoma medication. All patients had ECCE with PCIOL implantation and the follow-up period was at least 18 months. IOP was measured postoperatively at 3, 6, 9, 12 and 18 months and compared with preoperative IOP. RESULTS: Following the cataract extraction, PCIOL implantation produced a statistically significant reduction in IOP at all time points compared with the preoperative IOP during the study period (p < 0. 001). The mean preoperative IOP was 18.25 +/- 1.83 mm Hg; postoperatively at 1 month, it was 13.45 +/- 2.06 mm Hg; at 3 months 14.80 +/- 2.50 mm Hg; at 6 months 15.35 +/- 1.27 mm Hg, at 12 months 14.85 +/- 1.87 mm Hg and at 18 months 15.15 +/- 1.42 mm Hg (p < 0. 0008). The mean reduction in IOP was 16.98% from baseline at 18 months postoperatively. The mean number of antiglaucoma medication was reduced from 1.35/eye preoperatively to 0.60/eye postoperatively at 18 months (p < 0.0007). CONCLUSION: The result of our study revealed that ECCE with PCIOL implantation may be a reliable choice in controlling IOP in patients with CG.

Aged↗
PubMed1999

Electrocardiographic changes during subconjunctival injections.

Electrocardiographic changes were investigated in 53 patients during subconjunctival drug injections. Decrease in heart-rate of more than 10% or arrhythmia was observed in 25 (47.2%) of the patients, who were considered to have a positive oculocardiac reflex. In the control group of 35 patients, only 3 (8.6%) were found to have a significant decrease in heart rate during blood sampling from antecubital vein (p = 0.000). Young age was a significant risk factor for oculocardiac reflex during injections (p = 0.01). Patient gender, verbal pain score, satiety, experience of periocular injections, injected drug type were not found to be risk factors. All patients with oculocardiac reflex were asymptomatic; however, it is still wise to have emergency supplies ready for any circulatory derangement during subconjunctival injections.

Adolescent↗
PubMed1999

In vitro potency and stability of fortified ophthalmic antibiotics.

PURPOSE: This study evaluates the in vitro potency, stability and contamination of the fortified ophthalmic antibiotic preparations of cefazolin, vancomycin, gentamicin and tobramycin stored for 4 weeks. The effects of the different solvents and storage temperatures on the antimicrobial potency and stability were also examined. METHODS: The fortified stock solution of cefazolin and vancomycin were prepared by reconstituting with 0.9% sodium chloride and with artificial tears. Gentamicin and tobramycin were prepared by adding parenteral forms into their commercial ophthalmic solutions. The antimicrobial potency was measured by the minimum bactericidal concentration for cefazolin (33.3 mg/mL) and vancomycin (31 mg/mL) against Staphylococcus aureus, and for tobramycin (13.5 mg/mL) and gentamicin (13.5 mg/mL) against Pseudomonas aeruginosa. The stability of solution was evaluated by measuring absorbance spectra and pH. During the study period the levels of contamination of the stock solutions were examined by culturing on blood and on Sabouraud-dextrose media. RESULTS: There were no differences in the antimicrobial potency of the cefazolin, vancomycin and tobramycin within the 4-week period; however, the potency of gentamicin was decreased at both temperatures after 21 days. It was found that different solvents or storage temperatures had no effect on the potency. Throughout the 4-week period, no change was found in the absorbance spectra of gentamicin and tobramycin, whereas the absorbance spectra of cefazolin and vancomycin stored at 24 degrees C increased in both of the solvents used (P<0.05). In all of the antibiotics, pH changed at 24 degrees C after 7-10 days; however, at 4 degrees C, only the pH of tobramycin exhibited changes after 14 days (P<0.05). No contamination was detected in the stock solutions during the study period. CONCLUSION: Topical fortified antibiotic solutions used for longer than 7 days should be stored at < or =4 degrees C, those stored at 24 degrees C should be discarded after 7 days.

Anti-Bacterial Agents↗
PubMed1999

Effect of conjunctival structure and inflammatory cell counts on intraocular pressure after trabeculectomy.

PURPOSE: To evaluate the conjunctival structure and inflammatory cell counts and to determine the predictive value of these histological parameters for postoperative intraocular pressure (IOP) levels after trabeculectomy. METHODS: A clinical and histological study was performed on consecutive patients. Postoperative (mean 32. 8 +/- 18.4 months; range 6-60 months) conjunctival biopsies of 36 eyes of 28 primary open-angle glaucoma patients who had trabeculectomy between 1992 and 1995 were included in the study. According to postoperative pressure control, patients with < or = 16 mm Hg and those with >16 mm Hg were taken as groups 1 and 2, respectively. The control group (group 3) consisted of 15 age-matched patients without glaucoma, who had received no topical therapy. We compared the conjunctival structure and cell counts within these groups. Goblet cells, acute inflammatory cells, chronic inflammatory cells, fibroblasts, epithelial thickness, vascular density, mucopolysaccharides and collagen compositions were determined in groups 1, 2 and 3. RESULTS: The number of goblet cells was significantly higher in group 1 (6.74 +/- 7.23) than group 2 (3. 09 +/- 2.77; p = 0.017). No statistical difference was observed in the number of acute inflammatory cells, chronic inflammatory cells, fibroblasts, epithelial thickness, vascular density, mucopolysaccharide or collagen compositions between groups 1 and 2 (p > 0.05). In addition, when groups 1 and 2 were compared with the control group, there was a significant decrease in goblet cells (p < 0.001), an increase in acute inflammatory cells, chronic inflammatory cells, fibroblasts, epithelial thickness and vascular density (p < 0.001), but there was no significant difference in mucopolysaccharide and collagen compositions (p > 0.05). CONCLUSIONS: This study suggests that at the time of surgery a high number of goblet cells may be a predictor of lowered IOP (< or = 16 mm Hg) following trabeculectomy without antimetabolite.

Aged↗
PubMed1998

Volume-weighted mean nuclear volume in renal cell carcinoma.

OBJECTIVES: Tumor grade and stage are the most important prognostic parameters for renal cell carcinoma (RCC). The value of histologic nuclear grading, however, is impaired by the inconsistency of pathologists' observations. Estimate of volume-weighted mean nuclear volume (MNV), based on a stereologic method, is correlated with prognosis of bladder, prostate, and endometrial cancer. In this study, we investigated the prognostic value of stereologic estimation of nuclear volume in RCC. METHODS: This study included 62 patients with RCC who underwent radical nephrectomy between 1989 and 1996. Patients were evaluated in two groups: patients with locally advanced and/or metastatic disease were part of the poor prognosis group and patients with localized disease were part of the good prognosis group. Unbiased estimates of MNV were compared with histologic grade, tumor stage, and growth pattern according to Thoenes classification. Group means were compared using the nonparametric Kruskal-Wallis one-way analysis of variance. Univariate analysis of the data was performed for MNV and time to death, metastasis, local recurrence, and disease-free survival by paired sample t test. For categorical variables, Pearson's correlation test was used for statistical analysis. RESULTS: There was no correlation between MNV and patient sex, age, tumor stage, and growth pattern. MNV showed a trend to be higher in sarcomatoid and chromophilic cell types than in chromophobe and clear cell types (P < 0.05). MNV values were significantly higher with increasing grades but no MNV cutoff levels could be defined. The MNV values were not different between localized and locally advanced and/or metastatic disease. CONCLUSIONS: Our results indicate that estimates of MNV are not useful for predicting disease outcome. Further studies are needed to set up reproducible intervals of tumor dedifferentiation that could be carried out in routine practice for predicting progression.

Adult↗
PubMed1998

Additive effect of latanoprost and dorzolamide in patients with elevated intraocular pressure.

PURPOSE: To evaluate the additive ocular hypotensive effect of latanoprost and dorzolamide in combination, on intraocular pressure reduction in patients with elevated intraocular pressure (IOP). METHODS: Thirty patients with ocular hypertension or early capsular or primary open-angle glaucoma and elevated IOP were randomly assigned to two parallel treatment groups. The treatment period was twenty days. Fifteen patients (Group 1) received latanoprost once daily during the first ten days and, in addition, dorzolamide three times daily during the second ten days. Fifteen patients (Group 2) received dorzolamide three times daily during the first ten days and, in addition latanoprost, once daily during the second ten days. IOP was measured and conjunctival hyperemia was evaluated. RESULTS: In Group 1, the mean IOP on day 0 was 26.8 mm Hg; on day 10, 18.7 mm Hg; and on day 20, 15.9 mm Hg. In Group 2, the mean IOP on day 0 was 26.3 mm Hg; on day 10, 21.2 mm Hg; and on day 20, 16.1 mm Hg. Both groups had clinically significant IOP-lowering effect on day 10 as compared with baseline day (30.2% and 19.4% respectively) (p<0.01). When dorzolamide was added to latanoprost, the additional IOP reduction was 2.8 mm Hg (15%) (p<0.01) compared with 5.1 mm Hg (24.1%) (p<0.01) when latanoprost was added to dorzolamide. No local serious adverse reactions were observed. A mild but statistically significant increase in conjunctival hyperemia was seen in latanoprost applied patients. CONCLUSIONS: The results showed that latanoprost and dorzolamide can be combined successfully to reduce IOP with their additive effects.

Adult↗
PubMed1998

Renal effects of carbon dioxide insufflation in rabbit pneumoretroperitoneum model.

To determine the effects of carbon dioxide insufflation on renal function in a pneumoretroperitoneum model, 24 adult New Zealand rabbits were divided into four groups, six rabbits in each. The first group underwent a 2-hour CO2 insufflation at a pressure of 10 mm Hg in the retroperitoneal space after balloon dissection. In another group, the same procedure was maintained for 4 hours. In the sham-treated groups, the procedure was similarly carried out but without CO2 insufflation. In all four groups, serum and urine creatinine concentrations and renal artery and renal vein blood flow rates were determined separately at the beginning and at the end of the procedure and at 24 hours. Urine output was also recorded at the end of the procedure and at 24 hours. The serum creatinine in the 2- and 4-hour study groups had increased significantly at the end of the procedure, accompanied by a significant decrease in the urine creatinine value. Renal artery and renal vein blood flow rates and urine output were reduced in both groups during the study. All changes in the serum and urine creatinine, renal artery and vein flow rates, and urine output was more pronounced in the 4-hour group. All measures returned to their prestudy values by 24 hours. Pneumoretroperitoneum causes reversible renal dysfunction, which becomes more pronounced with prolonged insufflation. Further research is needed to show the impact of our findings in high-risk patients undergoing retroperitoneoscopic surgery.

Animals↗
PubMed1997

Contractility changes of the deep dorsal penile vein due to serotonin.

PURPOSE: Penile erection is a complex neurovascular phenomenon that takes place with the active contribution of arterial and sinusoidal structures. However, some authors claim that larger veins including the deep dorsal veins that produce contractions, might be involved in the physiology of erection. This study was designed to clarify the contractile properties of deep dorsal penile veins (DDPV). MATERIALS AND METHODS: The effect of serotonin (5-HT), noradrenaline (NA), adenosine triphosphate (ATP) and acethylcholine (Ach) on the isolated DDPVs of 16 impotent men, 9 with veno-occlusive dysfunction and 7 without venous leakage, and 5 potent men (controls) who underwent radical prostatectomy, were examined in vitro. RESULTS: Although NA, ATP and Ach had no effect, 5-HT produced concentration-dependent contractions. Emax and pEC50 of 5-HT were 411 +/- 10 mg., 5.92 +/- 0.25; 1020 +/- 260 mg., 5.83 +/- 0.24 and 160 +/- 40 mg., 6.4 +/- 0.22 in controls and patients who had venous leakage and no venous leakage, respectively. Samples of controls were contracted only with 5-HT2 agonist, DOI (pEC50 = 5.63 +/- 0.02), and these contractions were antagonized with 5-HT2 antagonist ketanserin. On the other hand, both DOI (pEC50 = 6.30 +/- 0.77) and 5-HT1 agonist, 5-CT (pEC50 = 6.23 +/- 0.21) produced venoconstriction in patients with veno-occlusive dysfunction. CONCLUSIONS: The present findings suggest that 5-HT receptor functions in the DDPVs are of 5-HT2 subtype in potent men and the altered response to 5-HT in patients with veno-occlusive disease may play a role in the pathophysiology of impotence.

Acetylcholine↗
PubMed1994

Open stone surgery: is it still a preferable procedure in the management of staghorn calculi?

We reviewed 43 patients with staghorn calculi to determine the effectiveness of various treatment modalities such as extracorporeal shock wave lithotripsy (ESWL) monotherapy, ESWL and percutaneous nephrolithotomy (PCNL) combined therapy, and open stone surgery. While ESWL monotherapy and ESWL+PCNL were performed in 25 and 8 patients, respectively, 10 patients underwent open stone surgery. Of the 25 patients treated with ESWL, 8 were stone-free, whereas 4 out of 8 patients treated with ESWL+PCNL and 8 out of 10 patients treated with open surgery were stone-free. The complications of ESWL monotherapy consisted of pyelonephritis in one patient, and stone street formation in three. In the group of ESWL+PCNL, one patient developed pyonephrosis, and another perinephritic abscess. No serious complication was noted in patients who underwent open surgery, but an average of 525 ml of blood transfusion was required. We conclude that open stone surgery, although invasive, is still beneficial in the treatment of staghorn calculi.

Adolescent↗
PubMed1993

Are obstructing ureteral stones more difficult to treat with extracorporeal electromagnetic shock wave lithotripsy?

In situ extracorporeal shock wave lithotripsy (ESL) has increasingly become accepted for the treatment of ureteral stones. However, treatment success is negatively affected by stone impaction or associated urinary obstruction. In order to assess the impact of obstruction on the outcome of in situ ESL, we reviewed the results in 503 patients treated in this way. The presence and severity of urinary obstruction was defined prior to ESL, being classified as no or mild obstruction (Group I) and moderate or severe obstruction (Group II). The stone-free rate in the nonobstructed group was 90%, whereas it was 85% in the obstructed group (P > 0.005). While all of our patients were treated on an outpatient basis, two patients in Group I and four patients in Group II required hospitalization with the diagnosis of pyelonephritis. All six patients were treated successfully with appropriate measures. No other serious complication occurred that required hospitalization. We conclude that urinary obstruction does not affect stone disintegration or passage and suggest that in situ ESL should be the treatment of choice in ureteral stones.

Adult↗
PubMed1992

Apraclonidine and clonidine: a comparison of efficacy and side effects in normal and ocular hypertensive volunteers.

We performed a prospective, randomized double blind study comparing the cardiovascular and intraocular pressure (IOP) effects of unilateral therapy with clonidine 0.125% and apraclonidine hydrochloride 1.0% in 15 normal and 15 ocular hypertensive volunteers. Baseline values were obtained prior to instillation. One drop of test medication (clonidine, apraclonidine or placebo) was instilled unilaterally, and the post-instillation measurements were taken at 1, 2, 4, 6 and 8 hours. Apraclonidine 1% produced a maximum 31.4% +/- 6.9% (4.83 +/- 1.17 mmHg) decrease in mean IOP in ocular normotensive volunteers and 33.9% +/- 6.9% (10.10 +/- 2.45 mmHg) in ocular hypertensive patients (p < 0.001). These values were 22.1% +/- 6.9% (2.90 +/- 1.94 mmHg) and 22.7% +/- 6.9 (6.80 +/- 2.31 mmHg), respectively in clonidine group (p < 0.001). In apraclonidine group, there were no changes in contralateral IOP, blood pressure or pulse rate. Clonidine produced a significant decrease in contralateral IOP, but this reduction was not statistically significantly different than that of placebo. In clonidine group, there was no change in pulse rate, but a significant decrease in blood pressure. Eyelid retraction, conjunctival blanching and mydriasis were noted in eyes treated with apraclonidine. However there were no statistically and clinically significant changes in pupil size or interpalpebral fissure width with clonidine. This study suggests that apraclonidine appears to be safer and more effective ocular hypotensive agent than clonidine in treatment of glaucoma.

Adrenergic beta-Agonists↗