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12 نتائج ل "Birteksöz Tan, Seher"
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Leukocyte Labeling with Tc-99m-HMPAO: The Role of Leucocyte Numbers and Medication on the Labeling Efficacy and Image Quality
The aim of this study is to evaluation of Tc-99m-hexamethylpropyleneamineoxime (HMPAO)-labeled leukocytes in terms of radiochemical, biochemical, and microbiological quality controls and to examine the effect of leukocyte numbers of the blood obtained from patients and the medications currently used by the patients on the radiochemical yields of Tc-99m-HMPAO-labeled leukocytes, and imaging quality was evaluated. Thirty paients were included in our study who applied to Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Department of Nuclear Medicine for Tc-99m-HMPAO-labeled leukocyte scintigraphy. Devices and chemicals used in the preparation of Tc-99m-HMPAO-labeled laukocytes were compared with other nuclear medicine clinics. Tc-99m-HMPAO-labeled leukocytes were evaluated in terms of radiochemical, biochemical, and microbiological quality controls. The effect of leukocyte numbers of the blood obtained from patients and the medications currently used by the patients on the radiochemical yields of Tc-99m-HMPAO-labeled leukocytes and imaging quality was evaluated. The pH range of Tc-99m-HMPAO was 6-8 and the radiochemical purity was 90±2.04% (n=30), the radiochemical yield of Tc-99m-HMPAO-labeled leukocytes was 51±2.18% (n=30), the radiolabeling yield of Tc-99m-HMPAO-labeled leukocyte increased as the amount of white blood cell in the blood increased and whether the patients used any antibiotic, blood thinners, insulin and blood pressure medications did not affect the radiolabeling yield of Tc-99m-HMPAO-labeled leukocytes. The number of erythrocytes were removed at a rate of >99% in LPR by starch solution (6% HES; in the hemocytometric examination of Tc-99m-HMPAO-labeled leukocytes performed zeroth and 4th h, living/dead cell ratio was found 97.5% and the product was sterile. Tc-99m-HMPAO was labeled with leukocytes successfully, and Tc-99m-HMPAO-labeled leukocytes was safely injected to the patients as sterile without loss of vitality and aggregation.
Solvent-Free Microwave-Assisted Extraction of Polyphenols from Olive Tree Leaves: Antioxidant and Antimicrobial Properties
Response surface methodology (RSM) and artificial neural networks (ANN) were evaluated and compared in order to decide which method was the most appropriate to predict and optimize total phenolic content (TPC) and oleuropein yields in olive tree leaf ( ) extracts, obtained after solvent-free microwave-assisted extraction (SFMAE). The SFMAE processing conditions were: microwave irradiation power 250-350 W, extraction time 2-3 min, and the amount of sample 5-10 g. Furthermore, the antioxidant and antimicrobial activities of the olive leaf extracts, obtained under optimal extraction conditions, were assessed by several in vitro assays. ANN had better prediction performance for TPC and oleuropein yields compared to RSM. The optimum extraction conditions to recover both TPC and oleuropein were: irradiation power 250 W, extraction time 2 min, and amount of sample 5 g, independent of the method used for prediction. Under these conditions, the maximal yield of oleuropein (0.060 ± 0.012 ppm) was obtained and the amount of TPC was 2.480 ± 0.060 ppm. Moreover, olive leaf extracts obtained under optimum SFMAE conditions showed antibacterial activity against and , with a minimum inhibitory concentration (MIC) value of 1.25 mg/mL.
In Vitro Skin Permeation and Antifungal Activity of Naftifine Microemulsions
Microemulsions are fluid, isotropic, colloidal systems that have been widely studied as drug delivery systems. The percutaneous transport of active agents can be enhanced by their microemulsion formulation when compared to conventional formulations. The purpose of this study was to evaluate naftifine-loaded microemulsions with the objective of improving the skin permeation of the drug. Microemulsions comprising oleic acid (oil phase), Kolliphor EL or Kolliphor RH40 (surfactant), Transcutol (co-surfactant), and water were prepared and physicochemical characterization was performed. skin permeation of naftifine from microemulsions was investigated and compared with that of its conventional commercial formulation. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was used to evaluate the interaction between the microemulsions and the stratum corneum lipids. American Type Culture Collection (ATCC) 10231 and were used to evaluate the antifungal susceptibility of the naftifine-loaded microemulsions. The microemulsion formulation containing Kolliphor RH40 as co-surfactant increased naftifine permeation through pig skin significantly when compared with the commercial topical formulation (p<0.05). ATR-FTIR spectroscopy showed that microemulsions increased the fluidity of the stratum corneum lipid bilayers. Drug-loaded microemulsions possessed superior antifungal activity against ATCC 10231 and . This study demonstrated that microemulsions could be suggested as an alternative topical carrier with potential for enhanced skin delivery of naftifine.
In vitro activities of antimicrobial peptides and ceragenins against Legionella pneumophila
Legionella pneumophila is a waterborne intracellular pathogenic bacterium, the most frequent cause of human legionellosis and a relatively common cause of community-acquired and nosocomial pneumonia. Some legionellosis outbreaks are related to the presence of biofilms, which provide a reservoir for L. pneumophila strains. We investigated the in vitro activities of antibiotics; erythromycin and doxycycline, antimicrobial peptides AMPs; melittin, LL-37 and CAMA (cecropin A (1-7)-Melittin A (2-9) and ceragenins; CSA-8, CSA-13, CSA-44, CSA-131 and CSA-138 against L. pneumophila. Isolation of Legionella strains was conducted according to ISO 1998. Minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs) and minimum biofilm eradication concentrations (MBECs) were determined using microbroth dilution techniques. MIC ranges for melittin, LL-37, and CAMA were 0.25-1, 1-4, and 2-8 µg ml , respectively. MIC ranges for CSA-8, 13, 44, 131, and 138 were 0.5-2, 0.5-1, 1-4, 0.5-2, and 1-2 µg ml , respectively, and MBEC values for the ceragenins were 10-160 µg ml . These results demonstrate that AMPs and ceragenins display broad-spectrum, in vitro activity against L. pneumophila. In particular, CSA-8, CSA-13 and melittin gave the lowest MICs and MBCs. We also observed that ceragenins are active against established L. pneumophila biofilms.
Postantibiotic effect of various antibiotics on Legionella pneumophila strains isolated from water systems
The postantibiotic effects (PAE) of azithromycin, clarithromycin, ciprofloxacin, and levofloxacin were investigated against Legionella pneumophila (L. pneumophila) strains isolated from several hot water systems of different buildings in Istanbul. Each strain in logarithmic phase of growth was exposed to concentrations of antibiotics equal to minimum inhibitory concentration (MIC) and 4× MIC for 1 h. Recovery periods of test cultures were evaluated after centrifugation using the viable counting method. The mean values of PAEs for the strains of L. pneumophila, azithromycin at a concentration equal to and 4 times of MIC values were found 1.75 ± 0.28 h and 4.06 ± 0.44 h, for clarithromycin 2.98 ± 0.70 h and 4.18 ± 0.95 h, for ciprofloxacin 2.97 ± 0.63 h and 4.70 ± 0.63 h, for levofloxacin 2.05 ± 0.33 h and 3.78 ± 0.46 h, respectively. All of the antibiotics showed increased PAE values in a concentration-dependent manner. The findings of our study may play useful role in selecting the appropriate timing of doses during therapy with antimicrobials to treat patients infected with L. pneumophila.
Antimicrobial activities of widely consumed herbal teas, alone or in combination with antibiotics: an in vitro study
Because of increasing antibiotic resistance, herbal teas are the most popular natural alternatives for the treatment of infectious diseases, and are currently gaining more importance. We examined the antimicrobial activities of 31 herbal teas both alone and in combination with antibiotics or antifungals against some standard and clinical isolates of , , , , , methicillin susceptible/resistant and . The antimicrobial activities of the teas were determined by using the disk diffusion and microbroth dilution methods, and the combination studies were examined by using the microbroth checkerboard and the time killing curve methods. Rosehip, rosehip bag, pomegranate blossom, thyme, wormwood, mint, echinacea bag, cinnamon, black, and green teas were active against most of the studied microorganisms. In the combination studies, we characterized all the expected effects (synergistic, additive, and antagonistic) between the teas and the antimicrobials. While synergy was observed more frequently between ampicillin, ampicillin-sulbactam, or nystatine, and the various tea combinations, most of the effects between the ciprofloxacin, erythromycin, cefuroxime, or amikacin and various tea combinations, particularly rosehip, rosehip bag, and pomegranate blossom teas, were antagonistic. The results of the time kill curve analyses showed that none of the herbal teas were bactericidal in their usage concentrations; however, in combination with antibiotics they showed some bactericidal effect. Some herbal teas, particularly rosehip and pomegranate blossom should be avoided because of their antagonistic interactions with some antibiotics during the course of antibiotic treatment or they should be consumed alone for their antimicrobial activities.
In vitro activities of antifungals alone and in combination with tigecycline against Candida albicans biofilms
may form biofilms, which are thought to underlie the most recalcitrant infections. In this study, activities of antifungal agents alone and in combination with tigecycline against planktonic cells and mature and developing biofilms of isolates were evaluated. Amphotericin B and echinocandins were found to be the most effective agents against mature biofilms, whereas the least effective agent was fluconazole. Furthermore, the most effective anti-fungal monotherapies against biofilm formation were amphotericin B and anidulafungin, and the least effective monotherapy was itraconazole. The combination of tigecycline and amphotericin B yielded synergistic effects, whereas combinations containing itraconazole yielded antagonist effects against planktonic cells. The combination of tigecycline and caspofungin exhibited maximum efficacy against mature biofilms, whereas combinations containing itraconazole exhibited minimal effects. Combinations of tigecycline with amphotericin B or anidulafungin were highly effective against biofilm formation. In summary, tigecycline was highly active against particularly when combined with amphotericin B and echinocandins.
Flavonoids and biological activities of various extracts from Rosa sempervirens leaves
Rosa sempervirens L. (Rosaceae) growing wildly in Turkey is used in folk medicine for various indications. Here, we report the isolation of four flavonoids and determination of the total phenolic and flavonoid contents and the antimicrobial and antioxidant activities of various extracts from R. sempervirens leaves. Antioxidant activity was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The total phenolic and flavonoid contents were determined using the Folin-Ciocalteu and AlCl 3 methods, respectively. The antimicrobial activity was evaluated by the broth microdilution method against seven microbial species. The ethyl acetate extract (E) had significant antioxidant activity with half maximal inhibitory concentration (IC 50 ) values of 3.96 in the DPPH and 2.92 µg/mL in the ABTS assay. The total phenolic (203.8 mg gallic acid equivalents/g extract) and total flavonoid (95.81 mg catechin equivalents/g extract) contents of the E extract were significantly higher as compared to other extracts. The E extract exhibited strong antimicrobial activity against Candida albicans with a minimum inhibitory concentration of 39 μg/mL. Quercetin 3-xyloside, quercitrin and hyperoside were isolated from the E extract and quercetin, from the chloroform extract, and quercetin and hyperoside were identified for the first time in this species. Quercitrin was found to be a major compound in the E extract. Antimicrobial activity of R. sempervirens was also reported for the first time. These results indicate that the E extract has significant antioxidant and antimicrobial activity, probably due to flavonoids as well as other phenolic compounds in the E extract, acting individually or in combination.
Biological Activities of Aerial Parts Extracts of Endemic Tanacetum Argenteum Subsp. Argenteum
The objective of the present study was to investigate the antimicrobial and anti-proliferative activities of n-hexane, chloroform, methanol and aqueous methanol extracts obtained from Tanacetum argenteum subsp. argenteum aerial parts. Antiproliferative activity was tested in vitro against four human cancer cell lines (A549: lung adenocarcinoma, Hela; cervix adenocarcinoma, HT-29: colon adenocarcinoma, MCF-7; breast adenocarcinoma) using MTT assay. Antimicrobial activity was assessed by micro-broth dilution technique against Staphylococcus aureus ATCC 29213, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis ATCC 14153, and Candida albicans ATCC 10231. Hexane extract inhibited proliferation of HT-29 and MCF-7 by 75 and 74% while chloroform extract against the same cancer cell lines displayed inhibition of 89 and 73% at the concentration of 30 μg/mL, respectively. Also, chloroform extract at the same concentration showed significant anti-proliferative activity against A-549 and HeLa with inhibition values of 75% and 62%. Chloroform extract exhibited moderate antibacterial activity against Staphylococcus aureus and S. epidermidis with the MIC values of 625 μg/mL. Methanol and aqueous methanol extracts showed weak antimicrobial activity against Staphylococcus epidermidis and Candida albicans with MIC values of 1250 μg/mL. The results showed that n-hexane and chloroform extracts have significant anticancer activity against cancer cell lines used in this study.
In vitro evaluation of antioxidant and antimicrobial activities of some Centaurea L. species
The purpose of this study was to investigate the antioxidant, antimicrobial activities and total phenolic contents of ten methanol extracts obtained by maceration from capitulums and aerial parts (except for capitulum) of five Centaurea species (C.stenolepis, C.kilaea, C.cuneifolia, C.iberica, C.solstitialis subsp. solstitialis). Free radical scavenging activities and total phenolic contents of the species were assayed by DPPH method and Folin–Ciocalteu method, respectively. The antimicrobial activity of the extracts were tested by the micro-broth dilution method against seven microbial species. In the DPPH radical scavenging assay, the IC50 values of tested ten methanol extracts were in range 1.767-4.665 mg while the total phenol contents of four extracts were found to range between 4.825 and 12.460 mg GAE/g dry material. Four extract showed moderate activity against Pseudomonas aeruginosa (MIC: 312 μg/ml), while six out of ten extracts exhibited moderate activity against Candida albicans (MIC: 312 μg/ml). The methanol extract prepared from the aerial parts of C.cuneifolia possessed weak activity against Staphylococcus aureus (MIC: 625 μg/ml).