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Mustafa Turan

Publications and source records attributed to Mustafa Turan.

At least 19 recordsLinked to original sources
PubMed2006

A comparative study of linear and non-linear regression analysis for ammonium exchange by clinoptilolite zeolite.

Ammonium ion exchange from aqueous solution using clinoptilolite zeolite was investigated at laboratory scale. Batch experimental studies were conducted to evaluate the effect of various parameters such as pH, zeolite dosage, contact time, initial ammonium concentration and temperature. Freundlich and Langmuir isotherm models and pseudo-second-order model were fitted to experimental data. Linear and non-linear regression methods were compared to determine the best fitting of isotherm and kinetic model to experimental data. The rate limiting mechanism of ammonium uptake by zeolite was determined as chemical exchange. Non-linear regression has better performance for analyzing experimental data and Freundlich model was better than Langmuir to represent equilibrium data.

Hydrogen-Ion Concentration↗
PubMed2006

Investigation of the relaxant effects of pinacidil and cromakalim on the sheep sphincter of Oddi.

BACKGROUND/AIMS: ATP-sensitive K+ (KATP) channels play an important role in the regulation of smooth muscle membrane potential. This study was designed to investigate the effects of pinacidil and cromakalim, KATP-sensitive channel activators, on sheep sphincters of Oddi (SO). METHODS: SO rings were mounted in a tissue bath and tested for changes in isometric tension in response to pinacidil (10(-9)-10(-4)M) and cromakalim (10(-9)-10(-4)M) in the presence or absence of glibenclamide (10(-6)M), a blocker of KATP channels. Furthermore, concentration-dependent contraction responses of carbachol were obtained. RESULTS: Carbachol (10(-9)-10(-5)M) induced concentration-dependent contraction responses in the SO rings. Pinacidil (10(-9)-10(-4)M) and cromakalim (10(-9)-10(-4)M) induced concentration-dependent relaxation in isolated SO rings precontracted with carbachol (10(-6)M). At their maximum effects, both pinacidil and cromakalim produced nearly full relaxation. In the presence of glibenclamide, concentration-relaxation curves for pinacidil and cromakalim underwent rightward parallel shifts. There were no significant differences between pEC50 and E(max) values of pinacidil and cromakalim in the absence of glibenclamide (10(-6)M) (p > 0.05), but pEC(50) values of pinacidil and cromakalim in the presence of glibenclamide (10(-6)M) were significantly reduced (p < 0.05). CONCLUSION: These results suggest that the relaxation caused in sheep SO by pinacidil and cromakalim is mediated through the same glibenclamide-sensitive KATP channel. Pinacidil and cromakalim have an equipotent relaxing effect in isolated sheep SO and they can be beneficial as alternative drugs for obtaining selective relaxation during SO manometry after controlled clinical studies.

Animals↗
PubMed2006

Comparative relaxant effects of YC-1 and DEA/NO on the sheep sphincter of Oddi.

BACKGROUND/AIMS: Nitric oxide (NO) is a major inhibitor in various parts of the gastrointestinal tract. This study was designed to compare the effects of YC-1, NO-independent soluble guanylate cyclase (sGC) activator, and DEA/NO, NO-nucleophile adduct, on sheep sphincters of Oddi (SO). METHODS: SO rings were mounted in a tissue bath and tested for changes in isometric tension in response to 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1, 10(-10)-10(-5)M), diethylamine/NO complex (DEA/NO, 10(-8)-10(-4)M). We also evaluated the effect of YC-1 (10(-6) and 10(-5)M) and DEA/NO (10(-5) and 10(-4)M) on the levels cyclic GMP (cGMP) in isolated SO. RESULTS: YC-1 (10(-10)-10(-5) M) and DEA/NO (10(-8)-10(-4)M) induced concentration-dependent relaxation of isolated SO rings precontracted with carbachol (10(-6)M). The pEC(50) value of DEA/NO was significantly lower than those for YC-1 (p < 0.05), with no change of E(max) values. YC-1 increased cGMP levels more than control, carbachol and DEA/NO groups (p < 0.05). CONCLUSION: These results show that YC-1 is a more potent relaxant than DEA/NO and causes more elevation of cGMP levels in isolated SO rings.

Animals↗
PubMed2006

Removal of ammonium ion from aqueous solution using natural Turkish clinoptilolite.

A study on ion exchange kinetics and equilibrium isotherms of ammonium ion on natural Turkish clinoptilolite (zeolite) was conducted using a batch experiment technique. The effects of relevant parameters, such as temperature, contact time and initial ammonium (NH(4)(+)) concentration were examined, respectively. The pseudo first-order, pseudo second-order kinetic models and intraparticle diffusion model were used to describe the kinetic data. The pseudo second-order kinetic model provided excellent kinetic data fitting (R(2)>0.990) and intraparticle diffusion effects ammonium uptake. The Langmuir and Freundlich models were applied to describe the equilibrium isotherms for ammonium uptake and the Langmuir model agrees very well with experimental data. Thermodynamic parameters such as change in free energy (DeltaG(0)), enthalpy (DeltaH(0)) and entropy (DeltaS(0)) were also determined. An examination of the thermodynamic parameters shows that the exchange of ammonium ion by clinoptilolite is a process occurring spontaneously and physical in nature at ambient conditions (25 degrees C). The process is also found to be exothermic. The results indicate that there is a significant potential for the natural Turkish clinoptilolite as an adsorbent material for ammonium removal from aqueous solutions.

Kinetics↗
PubMed2006

Asymptomatic kindred of patients with coronary events have increased peripheral T-cell activities.

T cells are involved in the pathogenesis of atherosclerosis. We aimed to search for any association between the peripheral T-cell activities and atherogenic risk factors in healthy subjects. Fifty male volunteers (age 22.0 +/- 2.4 years) were enrolled. No subject had any chronic disease or was under any drug treatment. Lymphocytes were isolated from heparinized venous blood and the proliferative responses to phytohemagglutinin (PHA) were measured from the amount of radioactive thymidine uptake by the lymphocyte DNA. T-cell activity responses of patients with a family history of coronary events were compared with others. The activity responses of smokers were compared with nonsmokers. Subjects with a positive family history of coronary events had higher PHA stimulated T-cell response and delta cpm (P < 0.05 for each). Total and low-density lipoprotein cholesterol levels of the subjects with a positive family history of cardiovascular events were positively correlated with the PHA-activated T-cell responses (P = 0.022, r = 0.604 and P = 0.015, r = 0.635, respectively). There was no significant difference between the T-cell activity responses of smokers and nonsmokers. No correlation was found between the biochemical parameters and T-cell activities in these groups. Peripheral T-cell activity responses to PHA are higher in the asymptomatic relatives of patients with coronary events. This may be a clue for the familial tendency of atherosclerotic diseases. Further follow-up studies are necessary to investigate the relationship.

Adult↗
PubMed2005

A multicenter study of patients with adult-onset Still's disease compared with systemic juvenile idiopathic arthritis.

Adult-onset Still's disease (AOSD) has often been regarded as the adult spectrum of systemic juvenile idiopathic arthritis (sJIA). The present study aims to compare the clinical and laboratory features, the disease course and the response to treatment in patients having AOSD with those having sJIA. Retrospective review of all available data that were filled out by adult and paediatric rheumatologists from six centers using a standard data extraction form was performed. A total of 95 patients with AOSD and 25 patients with sJIA were recruited for the study. The frequency of fever, rash, myalgia, weight loss and sore throat was higher in patients with AOSD. The pattern of joint involvement differed slightly. Laboratory findings were similar in both groups, except that liver dysfunction and neutrophilia were more common among adults. A multiphasic pattern dominated the childhood cases, whereas the most frequent course was a chronic one in adults. Corticosteroids and methotrexate were the most commonly employed therapy; however, chloroquine was another popular therapy in the adult group. We showed a difference in the rate of clinical and laboratory features between patients with AOSD and those with sJIA. AOSD and sJIA may still be the same disease, and children may simply be reacting differently as the result of the first encounter of the putative antigens with the immune system.

Adolescent↗
PubMed2005

SPA therapy in fibromyalgia: a randomised controlled clinic study.

OBJECTIVE: The aim of the present study is to evaluate the effectiveness of spa therapy in the management of fibromyalgia. METHODS: Thirty women with fibromyalgia were randomly assigned to either a spa therapy group or a control group. The spa therapy group (n = 16) had spa treatment for 2 weeks in addition to their medical treatment. The control group (n = 14) continued to have their medical treatment and/or daily exercises. An investigator who was blinded for the intervention assessed all the patients for 9 months. Improvements in Fibromyalgia Impact Questionnaire (FIQ), pain and number of tender points were primary outcomes. Secondary outcome measures were improvement in sleep disturbance, fatigue, gastrointestinal symptoms, anxiety, Beck Depression Inventory and patient's global evaluation. RESULTS: the spa group was found to be superior to the control group at the end of intervention in terms of FIQ, pain, tender point count, fatigue and patients' global assessment. This superiority remained for 6 months in FIQ, 1 month in pain and tender point count. CONCLUSION: It was concluded that the addition of spa therapy to medical therapy has both short- and long-term beneficial effects in female patients with fibromyalgia.

Adult↗
PubMed2005

In vitro effects of intravenous anesthetics on the sphincter of Oddi strips of sheep.

BACKGROUND: Intravenous anesthetics are often used for conscious sedation in endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincter of Oddi (SO) manometry. This study was designed to investigate the direct effects of some intravenous anesthetics on SO in sheep. METHODS: In sheep SO rings, changes in isometric tension in response to cumulative concentrations of intravenous anesthetics were determined, and values for Emax (mean maximal inhibition) and pD2 (i.e. the negative logarithm of the concentration for the half-maximal response, EC50) were compared. RESULTS: Meperidine (10(-7) to 3 x 10(-5) M), fentanyl (10(-7) to 3 x 10(-5) M), midazolam (10(-7) to 3 x 10(-5) M) and propofol (10(-7) to 3 x 10(-4) M) induced concentration-dependent relaxations on SO precontracted with carbachol (10(-6) M). Emax and pD2 values following meperidine, fentanyl and midazolam administration were significantly greater than after propofol (p < 0.05). There were no significant differences in Emax and pD2 values for meperidine, fentanyl and midazolam. CONCLUSION: These results suggest that meperidine, fentanyl and midazolam are equipotent relaxants in the sheep SO in vitro. The relaxatory effect of propofol was 10 times less potent compared to the above agents, and it can be beneficial during SO manometry in controlled clinical human studies.

Adjuvants, Anesthesia↗
PubMed2005

Lead removal in fixed-bed columns by zeolite and sepiolite.

The removal efficiency of zeolite (clinoptilolite) and sepiolite from lead containing aqueous solutions was investigated. A series of experiments were conducted in batch-wise and fixed-bed columns. Synthetic wastewaters containing lead (50 mg l (-1)) and acetic acid (0.001 N) along with untreated and regenerated clinoptilolites and sepiolites were used in the adsorption studies. Batch tests were mainly conducted to isolate the magnitude of lead precipitation from real adsorption. Adsorption isotherms for both abstraction and adsorption were constructed. The removal of lead is found to be a sum of adsorption induced by ion exchange and precipitation of lead hydroxide. The breakthrough curves were obtained under different conditions by plotting the normalized effluent lead concentration (C/C0) versus bed volume (BV). The ion exchange capacity of sepiolite and clinoptilolite for lead removal showed good performance up to approximately 100 and 120 BV where the C/C0 remained below 0.1, respectively. The lead removal capacity of clinoptilolite bed from wastewater containing only lead yielded 45% higher performance compared to that of acetic acid partly due to a decrease in the effluent pH and consequently in precipitation. Also, the presence of acetic acid in the sepiolite column decreased the bed volumes treated by about 40%. Removal efficiency of lead-acetic system both in untreated clinoptilolite and sepiolite columns was found higher than that in regenerated columns.

Acetic Acid↗
PubMed2005

Assessment of the energy dissipation parameters inside the draft tube of a liquid spout-fluid bed.

Spouted beds are fluid-particle contactors in which the fluid is introduced centrally through a nozzle instead of a distributor plate, resulting in a regular particle circulation pattern. To assess the suitability of such sytems to environmental engineering applications such as filter backwashing and biofilm systems, a priori knowledge of the energy dissipation parameters is essential. A new model is developed for evaluating the energy dissipation parameters inside the draft tube of spout-fluid beds. The shear stress, velocity gradient, and turbulence fluctuation parameters in the draft tube of a liquid spout-fluid bed are calculated with the help of an energy equation for flows carrying suspensions and the experimentally determined pressure losses inside the draft tube and compared with results for particulately fluidized beds. A spout-fluid bed with a draft tube provides higher shear stress inside the draft tube than a fluidized bed. The mean velocity gradient in the draft tube is comparable to and higher than in a fluidized bed and increases with solids fraction. The turbulence dissipation coefficient decreases very slightlywith increasing solids fraction for both systems. Consequently, according to the model calculations, a spout-fluid bed with a draft tube can be an alternative to the classical fluidized bed filter backwashing system.

Beds↗
PubMed2005

Chlorhexidine gluconate: an ideal scolicidal agent in the treatment of intraperitoneal hydatidosis?

Hydatid disease is a parasitic disease that is treated primarily by surgery. The most important complication of surgical treatment is spillage of the contents of the cyst, leading to secondary dissemination. In this study, the effect of chlorhexidine gluconate (Chx-Glu) was investigated in the treatment of experimental intraperitoneal hydatidosis (IPH). IPH was reproduced in 100 Wistar albino rats by inoculation with 1 ml of a suspension contained approximately 1500 viable protoscolices of Echinococcus granulosus following determination of scolicidal activity of chlorhexidine gluconate in vitro. Five minutes after protoscolex inoculation, 5 ml of the scolicidal solution was instilled into the peritoneal cavity: 0.9% NaCl (control group), 4.0% Chx-Glu, 0.4% Chx-Glu, and 0.04% Chx-Glu. After 6 months of follow-up, the rats were sacrificed, and the number of isolated cysts, peroperative and postoperative deaths, and toxicity were evaluated. Cyst formation did not occur in any of the Chx-Glu groups compared to the control group (p < 0.05), whereas it was detected in all of the control rats. In addition, to 4.0% Chx-Glu was found to be more toxic and to cause a high mortality rate compared to the 0.4% and 0.04% Chx-Glu groups and the control group (p < 0.05). Chx-Glu 0.04% was found to be the most potent, nontoxic agent; it is easily available, inexpensive, and highly potent in a short period of time at the low concentration. Chx-Glu 0.04% can be used safely in the treatment of intraperitoneal hydatidosis and hydatid cyst.

Animals↗
PubMed2005

The platelet count/mean corpuscular hemoglobin ratio distinguishes combined iron and vitamin B12 deficiency from uncomplicated iron deficiency.

Combined deficiencies of iron and cobalamin are common. The aims of this study were to investigate the significance of the parameters of the complete blood count (CBC) in differentiating microcytic anemia due to pure iron deficiency anemia (IDA) from anemia due to combined deficiencies of vitamin B(12) and iron (IDA-B12). The study was carried out with 122 patients (100 female) who had microcytic red blood cell indices with IDA-B12 and 105 patients (95 female) with IDA. Group IDA-B12 patients had decreased hemoglobin levels, mean corpuscular volumes, mean corpuscular hemoglobin (MCH) levels, and MCH concentrations but had increased platelet counts (PLT). Using these parameters, we developed a PLT/MCH ratio parameter that has high values when IDA is accompanied by cobalamin deficiency. The cutoff value of >12.00, with a 74.6% sensitivity and a 41.9% specificity, appears to be the most convenient value for screening. We advise measuring the levels of cobalamin in patients with IDA associated with a high PLT/MCH ratio.

Adult↗
PubMed2004

Different ELR (+) angiogenic CXC chemokine profiles in synovial fluid of patients with Behçet's disease, familial Mediterranean fever, rheumatoid arthritis, and osteoarthritis.

The aim of the present study was to determine synovial levels of ELR (+) CXC chemokines, known to attract mainly neutrophils to inflamed tissues by binding the neutrophil chemokine receptors CXCR1 and CXCR2 and promoting neovascularization in patients with various inflammatory disorders. The study group consisted of 14 patients with Behçet's disease and nine with familial Mediterranean fever. Fourteen patients with rheumatoid arthritis and 16 with osteoarthritis served as controls. Synovial chemokine levels were measured by two-step sandwich enzyme-linked immunosorbent assay, and significant differences were found in the various chemokines studied. In addition to its angiogenic properties, increased synovial levels of interleukin-8 by attraction of more neutrophils to synovial fluids might also be responsible for the acute synovitis in patients with Behçet's disease. However, the absence of chronic changes with the eventual development of pannus and erosions might result from relatively lower expression of interleukin-8 and the transient, short-lived nature of the arthritis observed in these patients.

Adult↗
PubMed2004

A functioning-desensitization paraganglioma which caused hemodynamic instability during tumoral resection: report of a case.

Paragangliomas are uncommon tumors arising from the neuroendocrine elements of the paraganglia. Their successful management is associated with many problems. We herein present the findings of a 22-year-old man in whom a paraganglioma was incidentally found and in which the clinical and previous operative behavior was functioning desensitization. As a result, preoperative medication was not performed; however, during the tumor resection the patient demonstrated hemodynamic instability.

Adult↗
PubMed2004

Color removal of reactive dyes from water by clinoptilolite.

The adsorption of reactive dyes on Gordes (Turkey) clinoptilolite was investigated by a series of batch and column adsorption experiments. Three reactive dyes (Everzol Black, Everzol Red, Everzol Yellow) were used in laboratory studies. Synthetic wastewaters were used and the ability of natural zeolite (clinoptilolite) and their modified form were examined. The adsorption results, in batch and column reactor, indicate that natural zeolite have limited adsorption capacities of the reactive dyes but are substantially improved upon modifying their surfaces with quaternary amines (HTAB). The degree of hydrophilicity is found to play an important role in the uptake of reactive dyes.

Adsorption↗
PubMed2004

Do vascular endothelial growth factor and basic fibroblast growth factor promote phenytoin's wound healing effect in rat? An immunohistochemical and histopathologic study.

BACKGROUND: This study was designed to determine the possible correlation between phenytoin and vascular endothelial growth factor and basic fibroblast growth factor in the wound healing process. METHODS: Sixty Wistar albino rats were divided into four groups, each containing 15 animals. The experimental groups received a daily phenytoin treatment (10 mg) for 3 or 7 days following 3-cm dorsal skin incisions on the midline; the control group incisions were treated with 0.5 mL of saline solution during the same time periods. After completion of treatments, all animals were killed, and skin tissue samples were obtained. RESULTS: Histopathologic examination of all groups revealed that there were significantly increased (p<0.05) amounts of fibroblasts, collagen deposition, and blood vessels in the phenytoin-treated groups when compared to the control groups. Although immunolocalization of vascular endothelial growth factor and basic fibroblast growth factor was weak in the 3-day phenytoin treatment groups, they were strongly expressed in the 7-day treatment group when compared to the control groups. CONCLUSION: The findings of this study demonstrate that the tissue alterations of the wound healing process could be accelerated by phenytoin and the potential local pathways of vascular endothelial growth factor and basic fibroblast growth factor.

Animals↗
PubMed2004

Investigation of the mechanism of nicotine-induced relaxation on the sheep sphincter of Oddi.

Possible mechanisms for nicotine-induced relaxation were investigated in the isolated sheep's sphincter of Oddi. Sheep's sphincter of Oddi rings were mounted in tissue bath with modified Krebs-Henseleit solution and aerated with 95% oxygen and 5% carbon dioxide. Tension was measured with isometric force transducers, and muscle relaxation was expressed as percent decrease of precontraction induced by carbachol. Nicotine (1 x 10(-5) to 3 x 10(-3) mol/L) produced concentration-dependent relaxation on sphincter of Oddi precontracted by carbachol (10(-6) mol/L). Nicotine-induced relaxation was 72.8 +/- 4.2% of precontraction with carbachol (10(-6) mol/L) (mean pD2 value, 3.76 +/- 0.05 mol/L). Nicotine-induced relaxation was not affected by N(w)-nitro L-arginine methyl ester (L-NAME) (3 x 10(-5) mol/L), methylene blue (10(-5) mol/L), indomethacin (10(-5) mol/L), hexamethonium (10(-5) mol/L), glibenclamide (10(-5) mol/L), 4-aminopyridine (10(-3) mol/L), tetraethylammonium (3 x 10(-4) mol/L), clotrimazole (10(-6) mol/L), 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) (10(-6) mol/L), and anthracene-9-carboxylate (9-AC) (10(-6) mol/L), but potentiated by bupivacain (10(-5) mol/L). A calcium-antagonizing effect of nicotine was not observed. The results suggest that nicotine-induced relaxation of the sheep's sphincter of Oddi is not mediated by the release of prostaglandins, nitric oxide (NO), or a related substance; by the activation of potassium channels or chloride channels; or by the stimulation of nicotinic cholinoceptors. Potentiation of the nicotine-induced relaxation by bupivacain indicates that blockade of sodium channels may play a role in this relaxation.

Animals↗