PET imaging of infection with a HYNIC-conjugated LTB4 antagonist labeled with F-18 via hydrazone formation.

Unlabelled: It was previously shown that the (99m)Tc-labeled hydrazinonicotinamide (HYNIC)-conjugated LTB4 antagonist MB81 visualized infectious foci in rabbits adequately and within a few hours after injection. Here, the bivalent HYNIC-conjugated LTB4 antagonist MB67 (analog of MB81) was fluorinated with (18)F via hydrazone formation and tested in vivo.

Methods: MB67 was [(18)F]-fluorinated via reaction of the [(18)F]-fluorinated intermediate p-[(18)F]-fluorobenzaldehyde ([(18)F]FB) and the HYNIC moiety of MB67 via hydrazone formation.

99mTc-labeled interleukin 8 for the scintigraphic detection of infection and inflammation: first clinical evaluation.

Unlabelled: Interleukin 8 (IL-8) is a chemotactic cytokine that binds with a high affinity to receptors expressed on neutrophils. Previous studies with various animal models showed that (99m)Tc-labeled IL-8 accumulates specifically and rapidly in infectious and inflammatory foci. The aims of the present study were to evaluate the safety of IL-8 in humans and to assess the value of (99m)Tc-IL-8 scintigraphy in patients with suspected localized infections.

Scintigraphic imaging of infectious foci with an 111In-LTB4 antagonist is based on in vivo labeling of granulocytes.

Unlabelled: Radiolabeled leukotriene B4 (LTB4) antagonist DPC11870 is able to reveal infectious and inflammatory foci in distinct animal models. Because previous studies showed that accumulation of (111)In-DPC11870 in the abscess continued although the tracer had cleared from the circulation, we decided to investigate the pharmacodynamics of (111)In-DPC11870 and determine the mechanism of accumulation of the radiolabeled LTB4 antagonist in the abscess.

Methods: (111)In-DPC11870 was intravenously injected in healthy New Zealand White rabbits and rabbits with intramuscular Escherichia coli infection.

99mTc-labeled interleukin-8 for scintigraphic detection of pulmonary infections.

Background: Interleukin (IL)-8 is a chemotactic cytokine that binds with high affinity to receptors on neutrophils. Previously we showed that (99m)Tc-labeled IL-8 is highly suitable for scintigraphic imaging in rabbit models of IM infection and of colitis.

Study Design: (99m)Tc-labeled IL-8 was tested for its potential to image pulmonary infection in three experimental rabbit models: aspergillosis in immunocompromised rabbits, pneumococcal (Gram-positive) pneumonia, and Escherichia coli-induced (Gram-negative) pneumonia in immunocompetent rabbits (four rabbits in each group).

Scintigraphic detection of pulmonary aspergillosis in rabbits with a radiolabeled leukotriene b4 antagonist.

Unlabelled: Radiolabeled chemotactic peptides have been studied for their applicability to the visualization of infectious and inflammatory foci. Because a radiolabeled leukotriene B4 (LTB4) antagonist allowed visualization of intramuscular E. coli abscesses in rabbits within a few hours after injection, we decided to test the imaging characteristics of this agent in a more clinically relevant model of pulmonary aspergillosis.

Relationship between neutrophil-binding affinity and suitability for infection imaging: comparison of (99m)Tc-labeled NAP-2 (CXCL-7) and 3 C-terminally truncated isoforms.

Unlabelled: The CXC chemokines are a family of closely related chemoattractant cytokines that bind to, attract, and activate neutrophils to variable degrees. In this study, the relationship between neutrophil-binding affinity and suitability for infection imaging was investigated in a selected group of CXC chemokines. Neutrophil-activating peptide-2 (NAP-2, 70 residues; also called CXCL7) binds with high affinity to the CXCR2 receptor on neutrophils.

Kinetics of 99mTc-labeled interleukin-8 in experimental inflammation and infection.

Unlabelled: The cytokine interleukin-8 (IL-8) binds with high affinity to the CXCR1 and CXCR2 receptors on neutrophils. In previous studies, we showed that (99m)Tc-IL-8 could rapidly and effectively delineate foci of infection and inflammation in rabbit models of intramuscular infection, colitis, and osteomyelitis. Here, the in vivo kinetics and pharmacodynamics of (99m)Tc-IL-8 are studied in detail.

A bivalent leukotriene B(4) antagonist for scintigraphic imaging of infectious foci.

Unlabelled: Several radiolabeled chemotactic peptides have been tested for their suitability to show infection and inflammation. Leukotriene B(4) (LTB(4)) receptor-binding ligands could be useful agents for revealing neutrophilic infiltrations because the LTB(4) receptor is abundantly expressed on neutrophils after an inflammatory stimulus. In this study, we investigated the in vivo and in vitro characteristics of a new hydrophilic (111)In-labeled LTB(4) antagonist.

99mTc-HMPAO-labeled autologous versus heterologous leukocytes for imaging infection.

Unlabelled: Radiolabeled autologous leukocytes are the gold standard for imaging infectious foci in patients. Good results have also been reported for radiolabeled heterologous leukocytes from noninfected donors. Until now, the 2 methods have not been directly compared.

Effects of coligand variation on the in vivo characteristics of Tc-99m-labeled interleukin-8 in detection of infection.

In our previous studies, interleukin-8 (IL-8) was labeled with (99m)Tc using hydrazinonicotinamide (HYNIC) as bifunctional coupling agent and tricine as coligand. This preparation showed excellent characteristics for imaging of infection in a rabbit model of soft-tissue infection. In the present study, the propylaldehyde hydrazone formulation of HYNIC was introduced to stabilize HYNIC-IL-8.