ABSTRACT
Objectives: 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. Methods: 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. Results: 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. Conclusion: 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.
ABSTRACT
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-1, 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-1, respectively, and MBEC values for the ceragenins were 10-160 µg ml-1. 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.
