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Biomedical subjects

B Sener

Publications and source records attributed to B Sener.

At least 37 records · Page 2Linked to original sources
PubMed2001

Penetration of topical fluconazole into human aqueous humor.

The purpose of this study was to determine the aqueous levels and pharmacokinetics of topical fluconazole 0.2% upon single and multiple drop applications. Forty-nine patients undergoing cataract surgery were given topical fluconazole 0.2%. They either received single drop or a loading dose of 1 drop per 5 min for 20 min. Aqueous samples were obtained during surgery 5, 15, 30, 45 and 60 min after the last drop. The samples were analysed by high-pressure liquid chromatography to determine aqueous concentrations. After single and loading dose applications peak aqueous levels were achieved at 15 min (3.35 +/- 0.64 and 7.13 +/- 0.79 microg ml(-1), respectively). Both had a steady decrease in concentration at 30, 45 and 60 min down to 4.06 +/- 0.37 microg ml(-1)with loading dose and undetectable levels with single dose application. Comparing the concentrations with the minimum inhibitory concentrations (MIC) of yeasts determined by the National Committee for Clinical Laboratory Standards showed that concentrations achieved with single dose applications were higher than MICs of Candida albicans and Candida parapsilosis and concentrations achieved after loading dose applications were higher than MICs of C. parapsilosis, C. albicans and Candida tropicalis. We concluded that topical fluconazole 0.2% penetrates into the aqueous humor in concentrations that satisfy MICs of most of the Candida strains. It can be a good alternative to Amphotericin B for treatment of Candida keratitis.

Administration, Topical↗
PubMed2001

Epidemiology of chronic Pseudomonas aeruginosa infections in cystic fibrosis.

Chronic lung infection with Pseudomonas aeruginosa is primarily responsible for pulmonary deterioration of cystic fibrosis patients. The purpose of this study was to type the P. aeruginosa isolates collected sequentially from cystic fibrosis patients, chronically colonized with P. aeruginosa, by random amplified polymorphic DNA fingerprinting-PCR (RAPD-PCR). Sequential P. aeruginosa isolates (n: 130) that had been collected from 20 CF patients over at least 9 years were investigated. The isolates were analyzed by RAPD-PCR using two arbitrary primers. Antimicrobial susceptibility testing of all isolates was performed by the disc diffusion method. RAPD-PCR typing demonstrated that strains dissimilar in colony morphotype and of different antibiotic susceptibility patterns could be of the same genotype. Some CF patients were colonized with a rather constant P. aeruginosa flora, with strains of different phenotypes but of one genotype. However, some patients may be colonized with more than one genotype. The results also demonstrated that there might be a risk of cross-colonization between CF patients followed-up at the same center.

Adolescent↗
PubMed2001

Antibacterial activity of fifth-generation dentin bonding systems.

Past concepts that the pulp does not become infected until an actual carious exposure takes place have been challenged. The antibacterial effects of the dentin bonding systems Single Bond, Prime&Bond NT, and Excite were evaluated using the bacteria Streptococcus mutans ATCC 25175, Streptococcus intermedius, Lactobacillus acidophilus, Prevotella oris, Prevotella bivia, Prevotella denticola, Porphyromonas gingivalis, Porphyromonas endodontalis, and Clostridium ramosum with a disk diffusion method. Chlorhexidine (0.2%) was used as a positive control. After incubation zones of inhibited bacterial growth were measured. Prime&Bond NT showed growth inhibition for all bacterial strains. Lactobacillus acidophilus and Streptococcus mutans were remarkably resistant to Single Bond, whereas EX produced no inhibitory effect on Porphyromonas endodontalis, although the adhesive produced the maximum halo inhibition to Streptococcus mutans (15+/-1 mm), showing an antibacterial effect closest to chlorhexidine. The variety of results obtained in this study suggest that antibacterial properties of current dentin adhesives may depend on components that are originally incorporated to promote adhesion.

Anti-Infective Agents, Local↗
PubMed2001

Toxicity of dietary Heliotropium dolosum seed to mice.

Experimental pyrrolizidine alkaloid intoxication was produced in inbred Swiss mice. Animals were fed diets containing 0, 1, 3, 5, or 10% Heliotropium dolosum seed for 24 w. The seeds contained 0.13% total alkaloid concentration composed of 4 specific components: lasiocarpine (78.79%), heliosupine (11.96%), echimidine (5.43%), and heliotrine (3.82%). Deaths occurred in all dosed groups and increased with dietary seed concentration. Massive to submassive liver necrosis together with sinusoidal congestion, and hemorrhage or multifocal hepatocytic necrosis was limited to animals which survived < 5 w and were fed on 10% seed. Moderate to severe hepatomegalocytosis, scattered single cell necrosis, and mild subcapsuler fibrosis were seen in all test group animals that survived > 5 w. Intranuclear eosinophilic inclusions in hepatocytes and bile duct and ductular cell hyperplasia were the most noticeable lesions in the 1, 3, and 5% groups. There was mild to moderate renal tubular megalocytosis in the 3, 5, and 10% groups. It seems likely that H dolosum seed, at least to a limited extent, constitutes a health hazard for certain animal species.

Animals↗
PubMed2000

Anti-ulcerogenic effect of Momordica charantia L. fruits on various ulcer models in rats.

The mature fruits of Momordica charantia L. (Cucurbitaceae) are used externally for the rapid healing of wounds and internally for the treatment of peptic ulcers in Turkish folk medicine. For the evaluation of the latter activity, ethanol-induced ulcerogenesis model in rats was employed. The olive oil extract of the material as well as dried-powdered fruits in filtered honey showed significant and dose-dependent anti-ulcerogenic activity against this model. A potent and dose-dependent inhibitory activity was also observed by the administration of ethanol extract of the fruits. For the bioassay-guided fractionation, the material was first extracted with hexane and then by ethanol and both extracts were found active against the same ulcer model. Furthermore, ethanol extract of the fruits showed significant activity against HCl-EtOH induced ulcerogenesis in indomethacin-pretreated rats and diethyldithiocarbamate-induced ulcer models.

Animals↗
PubMed2000

Apical nodular subepithelial corneal scar after retreatment in hyperopic photorefractive keratectomy.

PURPOSE: To report a complication, apical nodular subepithelial corneal scar, that can occur after hyperopic photorefractive keratectomy (PRK) retreatment. SETTING: Istanbul University Eye Research Center, Istanbul, Turkey. METHODS: Twelve eyes of 6 patients with apical nodular subepithelial corneal scar were retrospectively studied. Mean age of the 5 men and 1 woman was 30.2 years +/- 5.4 (SD). All eyes had hyperopic PRK retreatment for regression 9.5 +/- 1.44 months after primary hyperopic PRK. Mean spherical equivalent refraction of the residual hyperopia before retreatment was +4.67 +/- 0.81 diopters (D). All patients had a corneal haze grade of less than 1+. Hyperopic PRK retreatment was performed with a 193 nm excimer laser (Chiron Technolas Keracor 116). RESULTS: Apical nodular subepithelial corneal scars developed within the first month of hyperopic PRK retreatment and progressed until the third month in 12 eyes of 6 patients. The lesion was round and symmetrical in both eyes, smaller than 2.0 mm, and centrally located. During the mean 40.66 +/- 2.46 month follow-up, the lesion did not change in size or density. Mean spherical equivalent refraction after retreatment was 2.88 +/- 0.88 D (range +1.50 to +4.00 D) at 1 month and +4.36 +/- 1.83 D at last follow-up. Refraction was unmeasurable in 3 eyes. Five eyes lost 1 line of best spectacle-corrected visual acuity and 7 eyes, 2 or more lines. The surface regularity indexes were higher than 2.00 in all the eyes. CONCLUSION: Hyperopic PRK retreatment may cause the sight-threatening complication of apical nodular subepithelial corneal scar. This complication behaves unlike corneal haze and does not resolve spontaneously over time.

Adult↗
PubMed2000

Triterpenoid saponins from Bongardia chrysogonum.

Two new triterpenoid saponins, 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-alph a-L-arabinopyranosyl]-hederagenin (1) and 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-alph a-L-arabinopyranosyl]-hederagenin 28-O-[beta-L-glucopyranosyl-(1-->6)-beta-L-glucopyranosyl] ester (2), together with five known saponins, were isolated from an ethanolic extract of the tubers of Bongardia chrysogonum. The structures of 1 and 2 were determined on the basis of spectroscopic studies.

Chromatography, High Pressure Liquid↗
PubMed1999

Secondary laser in situ keratomileusis 1 year after primary LASIK for high myopia.

PURPOSE: To report the results of the laser in situ keratomileusis (LASIK) using a second-cut hinged corneal flap to treat regression 1 year after primary LASIK for high myopia. SETTING: Istanbul University, Eye Research Center, Istanbul, Turkey. METHODS: Six eyes of 4 patients who had a mean myopic regression of -6.20 diopters (D) +/- 1.10 (SD) 1 year after primary LASIK were retreated with secondary LASIK performed using the Automated Corneal Shaper (Chiron Vision) and a 193 nm excimer laser (Chiron Technolas, Keracor 116). Fluence was 130 mJ/cm2 and the repetition rate, 10 Hz. RESULTS: Mean follow-up was 12.16 +/- 0.75 months. At the last follow-up, the mean spherical equivalent was -0.18 +/- 0.77 D (range +0.12 to -1.25 D). Two eyes (33.3%) remained within +/- 0.50 D of emmetropia; 5 eyes (83.3%) were within +/- 1.00 D of emmetropia. No patient lost best spectacle-corrected visual acuity. No complications occurred such as detachment of the former corneal flap and rolling, irregularity, or tearing of the new corneal flap. CONCLUSION: Secondary LASIK was an effective, safe method to treat regression after primary LASIK for high myopia.

Adult↗
PubMed1999

New steroidal alkaloids from the roots of buxus sempervirens

Phytochemical studies on an EtOH-soluble extract of the roots of Buxus sempervirens of Turkish origin have resulted in the isolation of three new steroidal alkaloids, (+)-semperviraminol (1), (+)-buxamine F (2), and (+)-17-oxocycloprotobuxine (3), along with two known steroidal alkaloids, (+)-buxoxybenzamine (4) and (+)-buxapapillinine (5). The structures of 1-3 were elucidated with the aid of spectroscopic studies. Compounds 4 and 5 exhibited phytotoxic activity against Lemna minor.

Journal Article↗
PubMed1999

Neutrophil chemotaxis in acutely infected and clinically stable cystic fibrosis patients.

PURPOSE: The aim of the present study was to evaluate the role of neutrophil chemotaxis in cystic fibrosis (CF) and to also determine whether an acute bacterial infection and the nutritional status of a child can affect neutrophil chemotaxis. METHODS: Twelve acutely infected and 12 clinically stable CF patients and 10 healthy age-matched controls were studied. Neutrophil chemotaxis and random migration were investigated in vitro in the peripheral blood of subjects by the Boyden chamber method and the results were expressed as chemotactic index (CI). The nutritional status of the cases was evaluated as body mass index (BMI). RESULTS: The CI values in the acutely infected group were found to be significantly lower than the clinically stable and healthy control groups (P < 0.05 and P < 0.005, respectively). There was no significant difference between the clinically stable CF group and the healthy control group (P > 0.1). No significant correlation was detected between the CI and BMI of the two groups of CF patients (P > 0.05). CONCLUSIONS: The present study confirms that neutrophil chemotaxis and random migration are normal in clinically stable CF patients. The decreased CI in the acutely infected patients indicates the possible role of infection itself on neutrophil chemotaxis.

Acute Disease↗
PubMed1999

Corneal iron ring after hyperopic laser-assisted in situ keratomileusis.

PURPOSE: To report a new corneal iron ring after hyperopic laser-assisted in situ keratomileusis (LASIK). METHODS: Three patients underwent hyperopic LASIK for the correction of hyperopia in both eyes. Spherical equivalent refraction of the patients ranged from +3.37 to +6.50 diopters. LASIK procedure was performed using automated corneal shaper and 193-nm argon fluoride excimer laser. RESULTS: Both eyes of the patients were noted to have a corneal iron ring located at the paracentral area at 6-7 months after surgery. The localization of iron ring corresponded with outside border of central steep zone. Twelve-month examination showed there was no change in color, shape, and density of corneal iron ring. CONCLUSIONS: Corneal topographic changes induced by hyperopic LASIK may cause corneal iron ring to develop.

Adult↗
PubMed1999

Changes in tear flow and tear film stability after photorefractive keratectomy.

PURPOSE: To investigate the changes in tear flow and tear film stability after photorefractive keratectomy (PRK) for myopia. MATERIAL AND METHOD: One eye of 32 patients underwent unilateral PRK procedure for the correction of myopia ranging from -1.50 to -6.00 diopters (D) (mean -3.65 +/- 1.55 D). Schirmer test values and break-up time (BUT) scores were measured 6 weeks after the PRK procedure. Unoperated, contralateral eyes were used as control eyes for each patient. The Schirmer test scores and BUT values were statistically analyzed using independent t test. RESULTS: The mean Schirmer test value was 14.45 +/- 7.79 mm in the operated eyes. It was 28.83 +/- 5.89 in the control eyes. The decrease in Schirmer test value was statistically significant (t = 8.28, p = 0.0001). The mean BUT scores were 13.19 +/- 5.09 s in the operated eyes and 27.83 +/- 9.31 s in the control eyes. The decrease was statistically significant (t = 7.86, p = 0.0001). CONCLUSION: PRK causes a decrease in tear flow and tear film stability that is probably caused by decreased corneal sensation after PRK.

Adult↗
PubMed1999

Visceral and cutaneous leishmaniasis (report of 2 cases).

Leishmaniasis is an endemic, sporadic infection in many parts of the world. Turkey is geographically unique in linking Asia and Europe. Of special interest is leishmaniasis, as various forms of this disease have long been reported in the surrounding regions. Visceral and cutaneous leishmaniasis are endemic in the western and southeastern parts of Turkey, respectively. Here, we report a cutaneous and a visceral leishmaniasis case, to draw attention to the increase in the incidence of leishmaniasis in Turkey. In the patient with cutaneous leishmaniasis, the ulcerative lesion on the cheek had persisted for two months before admittance to the hospital. Direct smears prepared from this lesion were negative for leishmania amastigotes whereas the promastigote forms were maintained in NNN (Novy-MacNeal-Nicolle) medium. The second patient was hospitalized with a prediagnosis of haematological malignancy, but the smears prepared from the bone marrow aspirates revealed leishmania amastigotes and promastigotes were seen on the smears from NNN cultures. These two reports mark the importance of inoculation of the specimens to NNN medium for the recovery of the promastigote forms. Cutaneous and visceral leishmaniasis have become endemic in considerable number of foci in Turkey, possibly due to the cessation of vector control programmes and increase in the agricultural and irrigation areas. These two reports also point out the increased prevalence of leishmaniasis in Turkey after 1980's.

Animals↗
PubMed1998

Laser in situ keratomileusis after photorefractive keratectomy for myopic regression.

PURPOSE: To assess the efficacy and safety of laser in situ keratomileusis (LASIK) for regression after excimer laser photorefractive keratectomy (PRK). SETTING: Eye Research Center, Istanbul University, Istanbul, Turkey. METHODS: Laser in situ keratomileusis to treat residual myopia ranging from 1.50 to 12.50 diopters (D) (mean 5.96 D +/- 3.06 [SD]) was performed in 45 eyes of 25 patients. Cylindrical corrections were done in 7 eyes (15.6%) and spherical ablations, in 38 (84.4%). The mean interval between primary PRK and LASIK retreatment was 18.50 +/- 8.12 months. The procedure was performed under a hinged corneal flap using the Chiron Automated Corneal Shaper and Chiron Keracor 116 excimer laser. RESULTS: Six months after LASIK retreatment, mean spherical equivalent refraction was -0.67 +/- 0.77 D. Thirty-six eyes (80%) were within +/- 1.00 D of emmetropia. Uncorrected visual acuity was 20/40 or more in 31 eyes (68.9%); 2 eyes (4%) lost 2 lines of best spectacle-corrected visual acuity. There was no statistically significant difference in corneal haze before and after LASIK. CONCLUSION: Laser in situ keratomileusis was safe and effective for treating residual myopia after excimer laser PRK.

Adult↗