Biomedical subjects

A Işimer

Publications and source records attributed to A Işimer.

27 records · Page 2Linked to original sources

PubMed1995

Case report: ionisation tendency of a base metal alloy in the oral environment.

A biological interaction between the oral tissues and base metal alloys may result in corrosion and trace metal ion release, if the materials are not inert in the body. The reactions caused by such an alloy, a nickel-chrome alloy, were established on a woman patient who exhibited dark coloured band-like marks on the gingival tissues adjacent to her metal-ceramic crowns. These crowns were replaced by full ceramic crowns and the old restorations were analysed. The affected gingivae were removed, histopathological, patch and systemic tests were also performed. The results throw doubt on the biocompatibility of this alloy.

Adult↗

PubMed1994

Trace element (Al, Se, Zn, Cu) levels in serum, urine and tissues of burn patients.

Trace elements are known to play many important roles in humans. It has also been shown that some of these elements are essential in wound healing. In this study, aluminium, copper, zinc and selenium levels were determined in serum, urine and tissue samples of burned patients and the relationships between wound healing and trace elements were evaluated. Trace element levels were determined using atomic absorption spectrophotometry. During 20 days' treatment, a significant rise in aluminium levels was determined in serum, urine and tissue samples of patients. After day 5 of treatment, copper levels increased significantly only in urine samples. Zinc levels decreased in serum and tissue samples. However, zinc gave high values in urine within the first week then returned to the initial value. There was a significant decrease in zinc in serum and tissue samples taken from burned patients during treatment. Urine selenium levels showed a significant rise within the first 15 days.

Adult↗

PubMed1991

Selenium and Behçet's disease.

Behçet's disease is an inflammatory disorder of unknown etiology, characterized by recurrent oral and genital aphthous ulcers, ocular inflammation, and skin lesions of erythema nodosum and acneiform eruptions. Selenium (Se) affects all components of the immune system, i.e., the development and expression of nonspecific, humoral, and cell-mediated responses. In general, a deficiency in Se appears to result in immunosuppression, whereas supplementation with low doses of Se appears to result in augmentation and/or restoration of immunologic functions. In this study, the distribution of Se and IgG, IgM in serum were compared in samples from healthy adult control and Behçet's disease patients. The serum Se levels were measured by AA-30-40 Varian Spectra, and immunoglobulins were measured by immunodiffusion technique. The mean (SD) serum Se level of 54.24 +/- 8.06 ng/mL among Behçet's disease subjects was significantly different (P less than 0.01) from that in the control subjects (90.01 +/- 9.94 ng/mL). We also measured IgG and IgM as 10.01 +/- 2.74 mg/mL and 1.26 +/- 0.29 mg/mL, respectively for patients, and 15.08 +/- 4.73 mg/mL and 1.58 +/- 0.43 mg/mL for controls. The mean values of IgG and IgM for patients were significantly (P less than 0.05) different from the values of controls. It seems, therefore, that a deficiency in selenium impedes the humoral immune response.

Adult↗

PubMedDate not supplied

Plasma glutathione peroxidase activity and selenium levels of newborns with jaundice.

The plasma glutathione peroxidase (GSH-Px) and selenium (Se) levels were determined in 31 newborns affected by jaundice (NWJ). The GSH-Px levels of both full-term and premature newborns exhibiting jaundice and having a birthweight lower than 2000 g were significantly low (p < 0.05) when compared to controls. No significant differences were found in the corresponding Se levels, which were similar in all groups and independent of the pregnancy period and birthweight.

Glutathione Peroxidase↗

PubMedDate not supplied

Metabolic ratios of four probes of CYP2D6 in Turkish subjects: a cross-over study.

The relationships among the metabolic ratios for the standard probe drugs of CYP2D6 activity, such as debrisoquine, sparteine, metoprolol and dextromethorphan, were studied in 32 Turkish subjects. All subjects were randomly selected according to their phenotypes from a group of 111 Turkish subjects whose oxidation status had been tested for debrisoquine previously. All subjects were given a 10 mg debrisoquine tablet, a 100 mg sparteine tablet, a 100 mg. metoprolol tablet and a 20 mg dextromethorphan capsule orally with a wash-out period of at least 1 week between each probe administration. Metabolic ratios were calculated as percentage of dose excreted as parent drug/percentage of dose excreted as its hydroxymetabolite of parent drug in 0-8 h urine. Three poor metabolisers (PM) of debrisoquine were identified. They were also PMs of the other test probes and no misclassification by the 4 phenotyping methods was observed. All six correlations among the metabolic ratios of the 4 probe drugs assessed by Spearman's rank test were highly significant (P < 0.001). The present findings indicate that the oxidative metabolism of debrisoquine, sparteine, metoprolol and dextromethorphan is catalysed by the same cytochrome P450 in the Turkish subjects.

Adult↗

PubMedDate not supplied

Enhanced release of solid dispersions of etodolac in polyethylene glycol.

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.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMedDate not supplied

Effect of encapsulation of chloramphenicol in albumin microspheres on its in vitro transfer across the human placenta.

The possibility of reducing drug transfer across the placenta was tested in two of our previous studies. The aim of those studies was to demonstrate an alternative method of drug application during pregnancy which we think would yield a dual benefit, i.e. protecting the foetus from the harmful effects of drugs while curing the mother. The present study was planned as a continuation of the testing of the same idea and we tried to see the effect of albumin microsphere encapsulation of chloramphenicol on its transfer across the human placenta in vitro. Microspheres containing chloramphenicol were prepared according to the method previously described. The mean per cent encapsulation of chloramphenicol in albumin microspheres was found to be 42 +/- 4.3 per cent (n = 5) and the mean size of the albumin microspheres was 3.08 +/- 0.6 mm. In vitro stability of the drug-carrying microspheres was measured by dialysing them at 37 degrees C for 24 h. Chloramphenicol was released from the microspheres gradually leaving about 50 per cent of the entrapped drug in the microspheres after 1.5 h. About 20 per cent of the chloramphenicol was retained in the microspheres at 24 h postincubation. The persistence of the antibacterial effect of the released chloramphenicol is confirmed by antibiogramme tests. In the perfusions the initial free drug concentration was kept at 100 mg/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗

PubMedDate not supplied

Clarithromycin targeting to lung: optimization of the size, morphology and release characteristics of albumin microspheres.

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.

Animals↗

PubMedDate not supplied

Dissolution properties of different designed and formulated salbutamol tablet dosage forms.

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.

Albuterol↗