Fast determination of octinoxate and oxybenzone uv filters in swimming pool waters by gas chromatography/mass spectrometry after solid-phase microextraction.

A fast gas chromatography/mass spectrometry method was developed and validated for the analysis of the potential endocrine disrupters octinoxate and oxybenzone in swimming pool water samples based on the solvent-free solid-phase microextraction technique. The low-pressure gas chromatography/mass spectrometry method used for the fast identification of UV filter substances was compared to a conventional method in terms of sensitivity and speed. The fast method proposed resulted in 2 min runs, leading to an eightfold decrease in the total analysis time and a sevenfold improvement in detection limits. The main parameters affecting the solid-phase microextraction process were also studied in detail and the optimized conditions were as follows: fiber coating, polyacrylate; extraction mode, direct immersion; extraction temperature, 25°C; sample volume, 5 mL; extraction time 45 min; pH 6.5. Under the optimized conditions, a linear response was obtained in the concentration range of 0.5-25 µg/L with correlation coefficients in the range 0.990-0.999. The limits of detection were 0.17-0.29 µg/L, and the recoveries were 80-83%. Combined method uncertainty was assessed and found to be less than 7% for both analytes for concentrations equal to or higher than 5 µg/L. Pool water samples were analyzed to demonstrate the applicability of the proposed method. Neither octinoxate nor oxybenzone were detected in the swimming pool water samples at concentrations above the respective limits of detection.

Is anterior segment OCT superior to slit-lamp biomicroscopic examination for Kayser Flesicher ring in Wilson's disease?

OBJECTIVE: Detection of the Kayser-Fleischer (KF) ring in the diagnostic scoring and treatment follow-up of Wilson's Disease (WD) is important. Slit lamp (SL) biomicroscopic examination has traditionally been used in the evaluation of the KF ring. The role of Anterior Segment Optical Coherence Tomography (AS-OCT), which is used in various corneal diseases, in the detection of KF rings has attracted attention in recent years. In our study, we tried to demonstrate the effectiveness of AS-OCT in detecting the KF ring by comparing it with SL biomicroscopic examination. PATIENTS AND METHODS: 64 of 356 patients followed in our outpatient clinic due to WD were included in the study in the order of their admission to the outpatient clinic. The KF ring was evaluated in both eyes by SL-biomicroscopic examination and AS-OCT. Ophthalmic examination, and findings were performed by the same physician. RESULTS: Age range was 18-67 years, mean 33.06±10.83 years, gender was 39.1% (n: 25) female. At the time of diagnosis, the mean age was 19.48 ± 9.36 years, range was minimum 5 years and maximum 51 years. Clinical presentation was mixed type involvement n: 18 (28.1%), hepatic involvement n: 32 (50%), neurological involvement n: 14 (21.9%). The follow-up period was 2-257 months (74.6±76.16). The presence of KF ring was evaluated together with both AS-OCT and slit-lamp examination, the presence of KF could be detected in both AS-OCT and SL biomicroscopic examination in 10 patients (15.6%), in 12 (18.8%) of the cases KF ring is positive in AS-OCT but was negative in Slit-lamp biomicroscopic examination, in 65.6 (n: 42) of the cases OCT and slit-lamp biomicroscopic examination results were negative. CONCLUSIONS: The sensitivity of AS-OCT in detecting the KF ring was higher than the slit-lamp biomicroscopic examination. AS-OCT can detect early stage of KF rings in Wilson's Disease patients, so that diagnosis and treatment accuracy can be evaluated effectively.

The efficacy and safety of timolol maleate versus brinzolamide each given twice daily added to travoprost in patients with ocular hypertension or primary open-angle glaucoma.

PURPOSE: To compare the efficacy and safety of timolol maleate 0.5% versus brinzolamide 1% when added to travoprost 0.004% in patients with ocular hypertension or primary open-angle glaucoma. DESIGN: A prospective, double-masked, randomized, active-controlled, parallel comparison. METHODS: Qualified patients at Visit 1 were placed on travoprost dosed every evening for 4 weeks and then were randomized at baseline (Visit 2) to the addition of timolol maleate or brinzolamide each given twice daily. Patients returned to clinic at Week 4 (Visit 3) for a safety visit and Week 12 (Visit 4) for an efficacy visit. At Visits 2 and 4 the intraocular pressure (IOP) was measured at 08:00, 12:00, and 16:00 hours. RESULTS: Ninety-seven patients on brinzolamide had a baseline diurnal IOP of 21.5+/-2.2 mmHg and 95 on timolol maleate had 21.3+/-2.5 mmHg, each added to travoprost. The diurnal mean IOP at Week 12 was 18.1+/-2.7 mmHg for brinzolamide and 18.1+/-3.0 mmHg for timolol maleate (p=0.96). There was no statistical difference found between treatment groups in the absolute level of pressure, or in the reduction in IOP from baseline, at each time point or for the diurnal curve (p>0.05). There was no significant difference for any adverse event between groups (p>0.05), with the most common side effect being conjunctival hyperemia in 15/97 (16%) brinzolamide and 6/95 (6%) timolol treated patients (p=0.06). CONCLUSIONS: This study showed that brinzolamide provides similar safety and efficacy compared to timolol maleate when added to travoprost.

The effects of beta-blockers on ocular blood flow in patients with primary open angle glaucoma: a color Doppler imaging study.

PURPOSE: To evaluate the effects of four commonly used beta-blockers on ocular blood flow in patients with primary open angle glaucoma (POAG). METHODS: Eighty eyes of 40 subjects with POAG were included in the study. Subjects were randomly divided into four groups given timolol maleate 0.50%, betaxolol HCl 0.50%, carteolol 1% or levobunolol 0.50% drops, applied twice daily (one drug to each group). Before beginning the treatment and at the end of the first month ocular blood flow velocity was measured using the color Doppler imaging (CDI) method. In the ophthalmic artery (OA), central retinal artery (CRA) and temporal posterior ciliary artery (TPCA) the peak systolic (PS) and end-diastolic (ED) blood flow velocities were measured and resistive index (RI) values were calculated. The results within each group were analysed using the matched paired student's t-test. The data between groups was compared with one-way analysis of variance (ANOVA) and Tukey-Kramer multiple comparison tests. RESULTS: The timolol group showed a significant increase in RI values of TPCA. In the betaxolol group RI decreased significantly in CRA and TPCA, whereas in the carteolol group there was a significant decrease only in CRA. In the levobunolol group there was no change in any artery. CONCLUSIONS. Betaxolol seemed to have a greater vasodilator effect than carteolol, and levobunolol had no effect on the retinal and choroidal vasculature. Timolol may have some vasoconstrictive effect in the ciliary vasculature.

Nickel and chromium levels in the saliva and serum of patients with fixed orthodontic appliances.

The aim of this study was to evaluate the concentrations of nickel and chromium ions in salivary and serum samples from patients treated with fixed orthodontic appliances. A second aim of this study was to determine any significant changes in these concentrations during any period of the treatment time. Saliva and blood samples were collected from 100 patients ranging in age from 12 to 33 years. Twenty samples from each group were obtained. The groups were as follows: In the first group, saliva and blood samples were collected before insertion of the fixed appliances. In the second, third, fourth, and fifth groups, samples were collected at 1 week, 1 month, 1 year, and 2 years after appliance insertion. The serum was prepared by centrifuging the blood samples at 3000 rpm for 10 minutes. The fixed appliances consisted of an average of 4 bands and 20 bonded brackets. No palatal or lingual appliances welded to bands or extraoral auxiliary appliances were used. The spectrophotometric determinations were carried out using electrothermal atomic absorption spectrophotometry. The results indicated certain differences in the amounts of nickel and chromium released from fixed orthodontic appliances during different periods of treatment. The Mann-Whitney U-test from the SPSS statistics program was used to analyze the significance of the differences between no-appliance samples and those obtained with the appliances present. In the serum, there were statistically significant increases in ion concentration in the second-year groups. In saliva samples, nickel and chromium reached their highest levels in the first month and decreased to their initial level in the rest of the groups. It can be concluded that fixed orthodontic appliances release measurable amount of nickel and chromium when placed in the mouth, but this increase doesn't reach toxic levels for nickel and chromium in the saliva and serum.

Diode laser cyclophotocoagulation in refractory glaucoma: comparison between pediatric and adult glaucomas.

OBJECTIVE: To evaluate the outcome of contact transscleral diode laser cyclophotocoagulation (CTDC) in eyes with advanced glaucoma and to compare the efficacy in pediatric and adult patients. PATIENTS AND METHODS: Included in the study were 41 eyes (39 patients) with advanced glaucoma (15 eyes of 13 pediatric patients and 26 eyes of 26 adult patients). The patients were followed at least for six months or until failure of the procedure, if shorter than 6 months. The mean follow-up of all patients was 10 months (median 8 months, range 3-24 months); the mean pretreatment intraocular pressure (IOP) was 34.5+/-10.9 mm Hg for all cases, 36.2+/-12.6 mm Hg in adult cases and 31.6+/-6.5 mm Hg in pediatric cases. RESULTS: At last follow-up after first treatment, there was significant decrease in IOP and the mean reduction in IOP was 12.11+/-10.5 mm Hg for all eyes. The mean reduction in IOP adult (13.6+/-11.8 mm Hg) and (9.9+/-6.8 mm Hg) patients. While the success rate after the first diode laser therapy was 59%, it increased to 75% after retreatments. The most common complications were conjunctival hyperemia and anterior chamber reaction. There was no difference in the complication rate between the pediatric and adult cases. CONCLUSION: CTDC is a safe and effective therapy in eyes with advanced refractory glaucoma in the short term. But multiple applications may be needed in the long term. The results in adult and pediatric patients were found to be similar in efficacy and safety.

Direct atomic absorption spectrometry determination of tin, lead, cadmium and zinc in high-purity graphite with flame furnace atomizer.

This work described methodology of Sn, Pb, Cd and Zn impurities determination in high-purity graphite at direct atomic absorption spectrometry (AAS) with flame furnace (FF) atomizer. It was evidence that quality of AAS measurements are depended from sample amount, its homogeneity, particle size, as well as calibration procedure and operation parameters of FF atomizer. Prior to analysis the method has been developed and optimized with respect to the furnace heating temperature and flame composition of FF atomizer. Conditions of absorption peak areas (Q(A)) formation to each element were studied on the basis of contribution into its value some of individual parameters of analytes, including mass-transporting process from increasing mass of graphite samples into gas phase. Because particle size and homogeneous distribution of analyte in powdered materials has an enormous influence on accuracy and precision of measurement results, graphite as well as appropriate series of powdered reference standards was previously ground and investigated. Graphite samples to be analyzed and standard reference materials with mass from 0.025 to 0.200g was previously briquetted as pellet and insert on corresponding hole in furnace. The characteristic mass (g(0)) of Sn, Pb, Cd and Zn were 0.35, 0.1, 0.008 and 0.025ng, respectively, and relative standard deviation (S(r)) not more than 20%.