Browsing by Author "Bozkurt, A"

Now showing 1 - 10 of 10
  • No Thumbnail Available
    Item
    Effects of trauma and inflammation on the availability of ciprofloxacin in the vitreous cavity
    Kortunay, S; Öztürk, F; Kurt, E; Ilker, S; Inan, U; Basçi, NE; Bozkurt, A; Kayaalp, SO
  • No Thumbnail Available
    Item
    Load Forecasting Based on Genetic Algorithm-Artificial Neural Network-Adaptive Neuro-Fuzzy Inference Systems: A Case Study in Iraq
    AL-Qaysi, AMM; Bozkurt, A; Ates, Y
    This study focuses on the important issue of predicting electricity load for efficient energy management. To achieve this goal, different statistical methods were compared, and results over time were analyzed using various ratios and layers for training and testing. This study uses an artificial neural network (ANN) model with advanced prediction techniques such as genetic algorithms (GA) and adaptive neuro-fuzzy inference systems (ANFIS). This article stands out with a comprehensive compilation of many features and methodologies previously presented in other studies. This study uses a long-term pattern in the prediction process and achieves the lowest relative error values by using hourly divided annual data for testing and training. Data samples were applied to different algorithms, and we examined their effects on load predictions to understand the relationship between various factors and electrical load. This study shows that the ANN-GA model has good accuracy and low error rates for load predictions compared to other models, resulting in the best performance for our system.
  • No Thumbnail Available
    Item
    Penetration of topical and oral ofloxacin into the aqueous and vitreous humor of inflamed rabbit eyes
    Öztürk, F; Kurt, E; Inan, ÜÜ; Kortunay, S; Ilker, SS; Basci, NE; Bozkurt, A
    Purpose: This study aimed to investigate the penetration of topical and oral ofloxacin into aqueous humor and vitreous humor in post-traumatic endophthalmitis model in rabbits. Methods: A standardized intraocular infection after penetrating injury was made in the right eyes of 16 rabbits. Intraocular infection was induced by intravitreal injection of a suspension of Staphylococcus aureus. The intact left eyes were maintained as controls. The animals were divided randomly into two groups. (1) In the topical group, two drops of offloxacin 0.3% eyedrops were instilled to both eyes every 30 min for 4 h. (2) In the topical-oral group, two doses of 25 mg/kg of ofloxacin at 12-h intervals were given orally, then the protocol of the first group was applied. Aqueous and vitreous humor samples were taken 30 min after the last drop. Ofloxacin concentrations were measured by using HPLC. Results: Mean aqueous levels of ofloxacin in control eyes were: 3.25 +/- 2.55 mu g/ml in topical group, 4.58 +/- 5.39 mu g/ml in topical-oral group. Mean aqueous levels in inflamed eyes were: 5.21 +/- 4.55 mu g/ml in topical group, 10.34 +/- 8.88 mu g/ml in topical-oral group. Mean vitreous levels of ofloxacin in control eyes were: 0.17 +/- 0.07 mu g/ml in topical group, 1.30 +/- 1.23 mu g/ml in topical-oral group. Mean vitreous levels in inflamed eyes were: 0.35 +/- 0.22 mu g/ml in topical group, 3.48 +/- 2.69 mu g/ml in topical-oral group. There was no significant difference among the groups (P > 0.05), however. Conclusions: The result of this study suggests that oral supplementation of ofloxacin to topical instillation increased the ocular levels of ofloxacin in the post-traumatic endophthalmitis model. Mean drug concentrations in aqueous and vitreous humors were above the 90% minimum inhibitory concentrations (MIC90) for most of the common microorganisms causing endophthalmitis in all eyes, except in the vitreous humors of the intact eyes instilled topically. (C) 2000 Elsevier Science B.V. All rights reserved.
  • No Thumbnail Available
    Item
    Penetration of topical and oral ciprofloxacin into the aqueous and vitreous humor in inflamed eyes
    Öztürk, F; Kortunay, S; Kurt, E; Ilker, SS; Basci, NE; Bozkurt, A
    Purpose:To assess the aqueous and vitreous penetration of ciprofloxacin after topical and combined topical and oral administration and investigate the effects of inflammation on drug penetration. Methods: A standardized penetrating injury was made in the right eyes of 16 rabbits. Intraocular inflammation was induced by intravitreal injection of a suspension of Staphylococcus aureus in these eyes. The animals were divided into two groups according to treatment methodology: topical and topical-oral. The intact left eyes of the animals were maintained as controls. In the topical treatment group, two drops of ciprofloxacin 0.3% were instilled to both eyes every 30 minutes for 4 hours. In the topical-oral treatment group, animals were given two oral 40 mg/kg doses of ciprofloxacin at 12-hour intervals. After the last oral dose, the protocol of the topical group was applied to these eyes. Half an hour after the last drop, 100-muL samples were taken from aqueous and vitreous humor of ail eyes. Drug concentrations were measured using high-pressure liquid chromatography. Results: Mean aqueous levels of ciprofloxacin in control eyes were 2.31 mug/mL (range, 1.02-6.27 mug/ml) in the topical group and 5.88 mug/mL (1.52-17.81) in the topical-oral group. Mean aqueous levels in inflamed eyes were 7.36 mug/mL (2.34-17.15) in the topical group and 14.43 mug/mL (2.18-18.66) in the topical-oral group. Mean vitreous levels in control eyes were 0.77 mug/mL (0.09-1.93) in the topical group and 1.01 mug/mL(0.49-1.57) in the topical-oral group. Mean vitreous levels in inflamed eyes were 0.95 mug/mL (0.18-1.27) in the topical group and 1.98 mug/mL (0.51-3.34) in the topical-oral group. There was no significant difference among the groups (P > 0.05). Mean aqueous levels in all eyes and mean vitreous levels in the combined topical and oral group of inflamed eyes were above the 90% minimum inhibitory concentration for most of the common microorganisms causing endophthalmitis. Conclusion: There is an increase in both aqueous and Vitreous humor concentrations with inflammation and with oral and topical administrations, as opposed to topical only, of ciprofloxacin, Using oral as well as topical treatment may be a beneficial method of antibiotic prophylaxis in ocular trauma once a patient has received intravenous or intravitreal therapy.
  • No Thumbnail Available
    Item
    Effects of Herbal Essential Oil Mixture as a Dietary Supplement on Egg Production in Quail
    Çabuk, M; Eratak, S; Alçicek, A; Bozkurt, A
    One hundred and eighty 7-week-old laying quail were fed various diets over a 12-week period. The diets included a control diet (without essential oil mixture (EOM) or antibiotics (ANTs)), a basal diet including EOM (24 mg/kg feed), and a basal diet including an ANT (avilamycin, 10 mg/kg feed). Each treatment comprised 4 replications with 4 cages (15 quail per cage), amounting to 60 quail per treatment group. Diets (in mash form) and water were provided for ad libitum consumption. EOM consisted of 6 different essential oils derived from the following herbs: oregano (Origanum sp.), laurel leaf (Laurus nobilis L.), sage leaf (Salvia triloba L.), myrtle leaf (Myrtus communis), fennel seeds (Foeniculum vulgare), and citrus peel (Citrus sp.). In comparison with the control diet, adding supplements such as EOM and ANTs to the basal diet increased egg production in quail (P < 0.001). However, egg production was similar between EOM and ANT treatment groups. Moreover, there were no differences between the treatment groups with regard to egg weight. Feed intake was not affected by EOM or ANT supplementation, whereas feed conversion ratio was significantly improved by EOM and ANT supplementation. Thus, we concluded that EOM has beneficial effects as a dietary supplement on egg production and feed conversion ratio.
  • No Thumbnail Available
    Item
    Ofloxacin levels after intravitreal injection -: Effects of trauma and inflammation
    Öztürk, F; Kortunay, S; Kurt, E; Inan, ÜÜ; Ilker, SS; Basci, NE; Bozkurt, A; Kayaalp, SO
    Purpose: This study was carried out to get an insight into the ofloxacin elimination after intravitreal injection in rabbits. We also studied the effects of trauma and inflammation on the vitreous ofloxacin levels after intravitreal injection of ofloxacin. Methods: A penetrating eye injury in the right eye was inflicted on 24 rabbits and another 12 animals were used as control. A standardized intraocular inflammation was induced by intravit-real injection of a suspension of Staphylococcus aureus in half of the traumatized eyes. Ofloxacin (200 mu g/0.1 ml) was injected into the midvitreous cavity of both traumatized and control right eyes, and samples were obtained at 2, 8, 24 and 48 h after injection. Drug concentrations were measured using high-pressure liquid chromatography analysis. Results: Vitreous levels of ofloxacin were above the MIC90 at 2 and 8 h in all groups for most of the common microorganisms causing endophthalmitis and also at 24 h in traumatized-infected eyes. At the second hour, the mean vitreous concentrations of ofloxacin both in traumatized and traumatized infected eyes were lower than that in the control eyes (p < 0.05). At 8 h, the mean vitreous concentrations of ofloxacin in the traumatized and in the traumatized-infected eyes were higher than that in the control eyes (p < 0.05). At 24 h, the mean ofloxacin concentration was higher in the traumatized-infected eyes than that in control (p < 0.01) and traumatized eyes (p < 0.05), and also higher in the traumatized eyes than that in the control eyes (p < 0.05). The mean ofloxacin concentrations in the traumatized and traumatized-infected eyes were significantly higher (p < 0.01) than those in the controls at 48 h. The elimination half-life of ofloxacin in the control eyes was 5.65 h and trauma and inflammation prolonged the half-life to 9.47 and 9.72 h, respectively. Conclusion: Clearance of ofloxacin is fast and appears to be reduced by trauma and inflammation. Therapeutic drug levels in traumatized-infected eyes were maintained up to 24 h. This may be an important pharmacokinetic advantage in treating endophthalmitis unless the dose used has local toxicity and allows a longer dose interval when the dose is repeated.
  • No Thumbnail Available
    Item
    The effect of long-term use and inflammation on the ocular penetration of topical ofloxacin
    Öztürk, F; Kortunay, S; Kurt, E; Inan, ÜÜ; Ilker, SS; Basci, N; Bozkurt, A
    Purpose. To study the,penetration of ofloxacin into the aqueous and vitreous humors after long-term topical administration and to investigate the effects of inflammation on drug penetration in rabbits. Methods. A standardized model of intraocular infection after penetrating injury was achieved in the right eyes of 16 rabbits. The animals were randomly and equally-divided into two groups. The intact left eyes of the groups were maintained as the control. Ofloxacin eyedrops (0.3%) were instilled into all eyes at a frequency of 2 drops every hour for 7 hours in the first group and for 14 hours in the second group. Half an hour after the last drop, samples of the aqueous and vitreous humors were taken and ofloxacin concentrations were measured by using HPLC. Results. The mean aqueous humor concentrations of ofloxacin in control eyes after 7:and 14 hours of instillation were: 1.45 +/- 0.93 mu g/ml and 2.48 +/- 0.33 mu g/ml, respectively; those in infected eyes 2.35 +/- 1.84 mu g/ml and 3.49 +/- 1.47 mu g/ml, respectively. However the differences among the groups were not significant (p > 0.05). The vitreous ofloxacin concentrations in the control eyes were similar after 7 and 14 hours of instillation (0.23 +/- 0.14 mu g/ml, 0.27 +/- 0.10 mu g/ml, respectively). In infected eyes, the mean vitreous ofloxacin concentration after 14 hour of instillation was significantly higher than that in control eyes (p < 0.05; 0.4 +/- 0.09 mu g/ml, 0.29 +/- 0.11 mu g/ml, respectively). The mean vitreous ofloxacin concentration in infected eyes after 14 hours instillation was not significantly higher than that after 7 hours instillation. Conclusions. Topical ofloxacin instillation for 7 or 14 hours yields aqueous concentrations above the MIC90 for common ocular pathogens. Prolonged application and the presence of inflammation increased the penetration of ofloxacin into the vitreous humor.
  • No Thumbnail Available
    Item
    Effects of trauma and infection on ciprofloxacin levels in the vitreous cavity
    Öztürk, F; Kortunay, S; Kurt, E; Ilker, SS; Inan, ÜÜ; Basci, NE; Bozkurt, A; Kayaalp, SO
    Objective: This study was designed to determine the effects of trauma and infection on vitreous ciprofloxacin levels after intravitreal injection of ciprofloxacin in rabbits. Methods: A penetrating injury was made in the right eyes of 24 rabbits, in the eyes of half of the traumatized animals, a standardized intraocular infection was induced by intravitreal injection of a suspension of Staphylococcus aureus. The intact left eyes of the traumatized group were maintained as controls. Ciprofloxacin (200 mug/0.1 mL) was injected into the midvitreous cavity of both eyes in all animals and samples were obtained at 2, 8, 24, and 48 hours after injection. Drug concentrations were measured using high-pressure liquid chromatography analysis. Results: At the second hour, the mean Vitreous concentration of ciprofloxacin in the traumatized eyes was lower than that in control eyes (P < 0.05). The mean ciprofloxacin concentrations were significantly higher (P < 0.05) in the traumatized-infected eyes than were those in control or traumatized eyes at 24 and 48 hours. The elimination half-life of ciprofloxacin in control and traumatized eyes was 6.02 hours and 5.02 hours, respectively, and infection prolonged the half-life to 15.06 hours. Vitreous levels of ciprofloxacin were above the minimum inhibitory concentration (MIC90) for most of the common microorganisms causing endophthalmitis in all groups at 2 and 8 hours, but also at 24 and 48 hours in traumatized-infected eyes. Conclusion: Infection appears to decrease the clearance of ciprofloxacin. Therapeutic drug levels in traumatized-infected eyes were maintained up to 48 hours. Assuming that the animal model used may have a predictive Value for the drug elimination in traumatized-infected human eyes, we suggest that local administration of ciprofloxacin every 2 days may be relevant from the therapeutic perspective.
  • No Thumbnail Available
    Item
    The effects of prolonged acute use and inflammation on the ocular penetration of topical ciprofloxacin
    Öztürk, F; Kurt, E; Inan, ÜÜ; Kortunay, S; Ilker, SS; Basci, NE; Bozkurt, A
    Purpose: To study the aqueous and vitreous penetration of ciprofloxacin after prolonged acute topical administration and to investigate the effects of inflammation on drug penetration. Methods: A standardized model of intraocular infection after penetrating injury was made in the right eyes of eight rabbits. The intact left eyes were maintained as the control. Two drops of ciprofloxacin 0.3% eyedrops were instilled topically every 1 h for 7 h to all eyes of the rabbits. Aqueous and vitreous samples (100 mu l) were obtained half an hour after the last drop. Instillation was continued for 7 h more and samples were obtained as before. Drug concentrations were measured using HPLC. Results: The mean aqueous humor levels of ciprofloxacin were: in control eyes 1.31 +/- 0.78 mu g/ml after 7 h and 1.85 +/- 1.69 mu g/ml after 14 h of instillation; in inflamed eyes 2.18 +/- 1.02 mu g/ml after 7 h and 2.91 +/- 2.12 mu g/ml after 14 h. The mean vitreous humor levels were: in control eyes 0.65 +/- 0.44 mu g/ml after 7 h and 0.72 +/- 0.8 mu g/ml after 14 h of instillation; in inflamed eyes 0.67 +/- 0.77 mu g/ml after 7 h and 1.01 +/- 0.43 mu g/ml after 14 h. However, the differences among the groups were not significant (P > 0.05). Conclusions: Ciprofloxacin penetration into aqueous humor was higher in 14-h topical application than that for 7 h. Inflammation increased the penetration of topical ciprofloxacin into aqueous while administered for 7 h and into both aqueous and vitreous humor while administered for 14 h. (C) 2000 Elsevier Science B.V. All rights reserved.
  • No Thumbnail Available
    Item
    Treatment of manic patients during hospitalisation - a retrospective chart review in 2004-2008: what has changed?
    Yazici, O; Aydemir, O; Guloksuz, S; Akdeniz, F; Yenilmez, C; Akkaya, C; Cetinay, P; Ozpoyraz, N; Bozkurt, A; Oguzhanoglu, NK