Acute effect of erythropoietin on catecholamine levels in uremia.
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Biomedical subjects
Publications and source records attributed to Y Ozkan.
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Two hundred ninety-four stool sample obtained from primary schools of different social status and environmental conditions were examined for intestinal parasite. The age range was between seven and 13 years, 43% of the patients were females and 57% of the patients were males. In our study it has been observed that the parasite incidence was 29.3%. The predominant parasite was Giardia intestinalis (15.7%). Enterobius vermicularis (10.5%) and Ascaris lumbricoides (2.3%) have been followed respectively. There were three different parasites in the primary school of good social status and environmental conditions. In the contrary in the village school, there were five different parasites. In the conclusion parasite incidence was high in our region. In primary schools of different conditions there were no difference Giardia intestinalis but there were marked difference in the other parasites.
This work examines the release of etodolac from various molecular weight fractions of polyethylene glycol (PEG) solid dispersions. Solid dispersions of etodolac were prepared in different molar ratios of drug/carrier by using solvent and melting methods. The release rate of etodolac from the resulting complexes was determined from dissolution studies by use of USP dissolution apparatus 2 (paddle method). The physical state and drug:PEG interaction of solid dispersions and physical mixtures were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR) and differential scanning calorimetry (DSC). The dissolution rate of etodolac is increased in all of the solid dispersion systems compared to that of the pure drug and physical mixtures. The solid dispersion compound prepared in the molar ratio of 1:5 by the solvent method was found to have the fastest dissolution profile. The physical properties did not change after 9 months storage in normal conditions.
Simple, rapid and reliable spectroscopic methods (absorbance ratio and Vierordt) were compared with HPLC for quantitative determination in dissolution tests of benazepril-HCl (BNZ) and hydrochlorothiazide (HCT) in commercial tablets. A 249 nm wavelength was chosen as the isosbestic point in the absorbance ratio method, and the absorbance ratios A236/A249 nm for BNZ and A269/A249 nm for HCT were used for calculation of regression equations. For the Vierordt method, A1(1) values (%1.1 cm) obtained at 236 and 269 nm for both substances were used for quantitative analyses of BNZ and HCT. In the HPLC method, simultaneous determination of BNZ and HCT from dissolution medium was achieved using the mobile phase containing phosphate buffer (0.01 M, pH 6.2) and acetonitrile (65:35) on a Supelcocil LC-18 (4.6 x 250, 5.6 mm) reversed phase column. Dissolution tests of commercial tablets were carried out according to USP XXII paddle method in 0.1 N HCl at 50 rpm at 37 +/- 0.5 degrees C. Comparison of the dissolution data from the HPLC and two spectroscopic methods indicated that spectroscopic and HPLC methods were in good correlation with each other. Therefore, it was concluded that both spectroscopic methods as well as HPLC can be used in routine analyses of BNZ and HCT in dissolution tests of commercial tablets.
The increased production of reactive oxygen species (ROS) from activated neutrophils in Behçet's disease (BD) and recurrent aphthous stomatitis (RAS) may result in increased oxidative stress. Uric acid can react rapidly with neutrophil-derived ROS to form allantoin. The purpose of the study was to evaluate the serum levels of allantoin as a new marker of oxidative stress in BD compared with malondialdehyde (MDA) levels as a well-known marker. Blood samples were obtained from 23 BD patients, 22 RAS patients as positive controls, and 21 healthy controls. When compared to the healthy controls, we found higher allantoin and MDA levels in the BD patients and higher MDA levels in the RAS patients. Serum ascorbic acid levels in the BD patients were significantly lower than in the controls. Increased allantoin and MDA levels suggest the possible involvement of free radicals in BD. As allantoin is only a product of uric acid oxidation by reactive oxygen and nitrogen species, it may also be used as a marker of oxidative stress in BD.
PURPOSE: To compare topographic indices of surface regularity in dry eye patients and in normal subjects (controls) and to investigate the short-term effect of lacrimal punctal plugs on these indices in dry eye patients. METHODS: The surface regularity index (SRI) and surface asymmetry index (SAI) of the TMS-2 corneal topographic modelling system were used to evaluate corneal surface regularity in 20 eyes of 10 dry eye patients before and after the insertion of Herrick silicon lacrimal plugs (Lacrimedics, Rialto, CA, USA) and in 24 eyes of 12 normal subjects as controls. RESULTS: SRI and SAI were significantly lower in controls than dry eye patients (p=0.00). Median SRI was 1.72 in dry eye patients before punctal occlusion and 0.525 in the control group. Median SAI was 1.305 in dry eye patients and 0.240 in controls. After lacrimal punctal occlusion, Schirmer test results and fluorescein breakup time increased in nine patients and remained the same in one patient. After occlusion, the SRI decreased in 9 eyes, and increased in 11 (p=0.970); SAI decreased in 13 eyes and increased in 7 (p=0.135). CONCLUSIONS: No significant change in topographic indices of corneal surface irregularity could be detected in severe dry eye patients with lacrimal punctal plugs in the short-term follow-up.
Potential beneficial effects of outer and inner ostrich eggshell membranes alone and in combination with the shell powder on bone regeneration in cranial defects of 18 rabbits were investigated using radiological, clinical and histological methods. Three 6 mm wide, half-thickness defects were made in the calvarial bones of each rabbit. One defect remained empty as a control; prepared eggshell membranes were extended across the other two defects; and prepared eggshell powder was inserted inside the membrane in one case. Either alone or in combination with eggshell powder, the outer and inner ostrich eggshell membranes produced little adjunctive effect under the conditions and duration of this experiment.
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Dissolution can best be described as a tool that can provide valuable information about the availability of a drug product. In this study, nine different paracetamol tablet dosage forms available on the Turkish Drug Market have been investigated and physical controls were realized. Paddle and rotating basket apparatus methods were applied to all the formulations. In order to evaluate the dissolution rates, five different kinetics have been studied and the best fitting kinetics was found to be the Hixson-Crowell kinetics. It was found that all the preparations are in accordance with the Pharmacopeia standards.
Micropheres are drug carrier system which ensures controlled release in the shape of solid sphere particles with variable diameter distributions from a few microns to a milimeter of size. The active substance is dispersed in molecular level or in forms of macroscopic particles. Clarithromycin was selected as the model active substance in our study. Clarithromycin microspheres were prepared and evaluated by an emulsion polymerization technique. Two matrix materials have been considered as the basis in preparing the selected model active substance. Natural human serum albumin and bovine serum albumin, which were frequently used in early microsphere studies and are being used in some studies as microshpere matrix material were used. Albumin microspheres containing clarithromycin were prepared by heat stabilization at different stirring rate. In the first part of our study, drug content, payload, particle size, surface morphology and release characteristics from microspheres prepared.
Pharmaceutical availability or in vitro availability is one of the aspects of drug bioavailability. Dissolution can be described best as a tool that can provide valuable information about the availability of a drug product. Dissolution test was performed on three different designed and formulated of salbutamol tablet formulations marketed in Turkey. The test methods were the paddle method and the rotating basket method described in United States Pharmacopeia. All studied formulations showed a good agreement with pharmacopeial requirements. In particular all studied commercial tablet formulations showed a quite fast release of the antiasthmatic drug. Other type of table formulations showed slow release. In order to evaluate the dissolution rates five different kinetics have been examined and the best fitting kinetics was found to be RRSBW kinetic.
In this study, the effects of surface-active agents in different types and concentrations, added into the coating solution, on release of model hydrophilic compound have been examined. For this purpose, the tablets, prepared with the use of methylene blue as a model substance, were coated by spray coating technique with cellulose acetate solution containing polyethylene glycol 400 as a plasticizer. In addition, cetylpyridinium chloride as cationic surface-active agent and sodium lauryl sulphate as anionic surface-active agent were added into coating solution in different concentrations. After creating a delivery orifice by a microdrill on the tablets, release of model hydrophilic compound was tested by the USP paddle method. The data obtained were evaluated according to the different kinetics and the mechanism of release from the preparations was examined. The surface properties of the coating material were investigated by scanning electron microscope taken before and after the contact with medium fluid, as well as the mechanical properties by tensile tests. In conclusion, it has been found that the cationic surface active agent, cetylpyridinium chloride reduced the lag time, observed during the release of model hydrophilic compound, as a result of its enhancing effect on wettability of tablets by reducing the contact angle between the medium fluid and the coating material. On the other hand, the anionic surface active agent, sodium lauryl sulphate has been inactivated possibly due to the interaction with model hydrophilic compound that has cationic properties and/or substances contained in membrane composition; thus, the lag time has not decreased and furthermore, a significant decrease in the delivery rate of model hydrophilic compound has been observed.