indium-oxine and Escherichia-coli-Infections

The goal of the study was to investigate whether or not gram-negative organisms that secrete antichemotactic factors cause the nonaccumulation pattern of 111In-oxine-labeled white blood cell (111In-WBC) scans.. Staphylococcus aureus (gram-positive) (group 1) was injected into 25 rabbits and Escherichia coli (gram-negative) (group 2) into another 25 to induce infection in the lumbar vertebrae or left thigh bone (femur). Sixteen successfully infected and surviving rabbits from each group were used for imaging and analysis. Of the 16 rabbits, each group included 8 with vertebral infection and 8 with femur infection. For imaging, each rabbit was injected intravenously with 11.1 MBq (300 μCi) 111In-WBC, and images were acquired 24 h later. Microscopic histopathology was performed after decalcification to confirm osteomyelitis.. The 111In-WBC accumulation was observed in 7 (87.5%) of the 8 rabbits infected with S. aureus in the vertebrae and thigh bone. Of the rabbits infected with the gram-negative vertebrae, 1 (12.5%) showed little accumulation of 111In-WBC. Of the 8 rabbits with gram-negative-infected femurs, 1 had high accumulation and another had low accumulation of 111In-WBC, while the rest did not show any uptake. Osteomyelitis was confirmed by histopathology in all the successfully infected rabbits used for imaging.. In the majority of the gram-positive-infected rabbit vertebrae there was high accumulation of 111In-WBC. However, no accumulation of 111In-WBC was observed in most of the vertebrae infected with gram-negative organisms, which release antichemotactic factors that prevent adequate accumulation of WBC at the infected area.

Topics: Animals; Disease Models, Animal; Escherichia coli; Escherichia coli Infections; Femur; Leukocytes; Lumbar Vertebrae; Male; Organometallic Compounds; Osteomyelitis; Oxyquinoline; Rabbits; Radionuclide Imaging; Staphylococcal Infections; Staphylococcus aureus

These studies were designed to evaluate the correlation between morphologic and functional changes after heterotopic auxiliary small bowel isograft with systemic venous drainage and two ostomies in 20 Lewis rats. Morphologic damage of the graft was scored by full-thickness biopsies before surgery and 1, 3, 5, and 7 days after transplant. Functional evaluation of the graft was done, at the same time points, by urinary excretion of lactulose and mannitol injected in the proximal ostomy. The intestinal permeability was also studied by injecting Escherichia coli labeled with indium-111 oxine in the proximal ostomy. Translocation of radiolabeled bacteria was quantitated in extraintestinal tissues by radionuclide counts and number of viable organisms and in vivo by scintigraphic imaging. One day after transplant, significant graft damage (score 17.2 +/- 4.2) was observed when compared with the pretransplant value (7.3 +/- 2.6). The degree of tissue injury was similar on days 3 (15.8 +/- 3.5) and 5 (16.1 +/- 3.9) after transplant and remained high on day 7 (11.8 +/- 2.8). The lactulose to mannitol ratio showed a significantly increased permeability on day 1 (17.5) versus pretransplant values (2.6), remained high on day 3 (8.6), and returned to normal values on day 5 (2.8). Translocation of bacteria to distant organs, as measured by both radionuclide counts and number of viable organisms, was strikingly enhanced on day 1 after transplantation, compared with control animals, but returned to the pretransplant value on day 3. A good qualitative and quantitative correlation was observed between radionuclide counts in the extraintestinal organs and in vivo images obtained by scintigraphic scanning. In conclusion, in this model, timing and degree of bacterial translocation do not seem to correlate well, with the exception of the acute post-transplantation phase, with morphologic and permeability changes of the graft. Evaluation of translocation by scintigraphic imaging appears a suitable approach to study in vivo the kinetics and distribution of this process.

Topics: Animals; Escherichia coli; Escherichia coli Infections; Graft Survival; Indium Radioisotopes; Intestine, Small; Lactulose; Liver; Lung; Male; Mannitol; Organometallic Compounds; Oxyquinoline; Permeability; Postoperative Complications; Rats; Rats, Inbred Lew; Time Factors; Transplantation, Isogeneic

Leucocyte sequestration in various organs during endotoxin-induced shock in sheep was studied using leucocytes labelled with indium 111 oxine. A moderate dose of Escherichia coli endotoxin (10 micrograms/kg body weight) was slowly infused intravenously in 16 sheep, 9 of which subsequently received a continuous i.v. infusion of low-molecular-weight dextran (LMWD) given at an infusion rate of 15 ml/h over 4 h, starting 30 min after administration of the endotoxin. By that time, signs of acute lung injury had developed, thus mimicking a clinical situation. The remaining animals were untreated and served as controls. A marked increase in lung, liver and kidney leucocyte sequestration, together with a sharp, corresponding drop in splenic activity and leucocyte count in peripheral blood, occurred shortly after the endotoxin infusion in both groups. However, after 90 min there was a significantly lower leucocyte activity in the lungs, liver and kidneys of LMWD-treated animals as compared with controls. Less marked hemodynamic and respiratory alterations were also observed in animals treated with LMWD. The present study confirms previous reports that significant leucocyte sequestration in the lungs occurs early during endotoxemia. Furthermore, we found that leucocyte sequestration also occurs in the liver and kidneys, which could explain the development of multi-organ failure, frequently described in clinical sepsis. Even after injury to organs, LMWD infusion seems to be beneficial by significantly lowering leucocyte sequestration and could therefore be justified as an addition to the arsenal of interventions used in the treatment of endotoxemia.

Topics: Animals; Dextrans; Endotoxins; Escherichia coli; Escherichia coli Infections; Indium Radioisotopes; Leukocytes; Organometallic Compounds; Oxyquinoline; Radionuclide Imaging; Sheep; Shock, Septic

It has been reported in earlier in vitro studies that soft tissue trauma and endotoxin-induced shock causes pulmonary platelet trapping (PPT). This paper describes a noninvasive in vivo technique for dynamic studies of PPT in rabbits. Autologous platelets were labeled with 111In and reinfused into the animals. The following day, the rabbits were anesthetized and placed in a supine position under a scintillation camera. Continuous measurement of the activity distribution in the animal was performed for 35 min. The first 5 min represented a preshock measurement, whereafter endotoxin E. coli was injected IV. The following 2-3 min showed a sudden increase of radioactivity in the lungs indicating PPT, and thereafter a slow decrease to almost the preshock level. A simultaneous decrease in the number of platelets and the radioactivity in peripheral blood also indicated the induction of PPT. This study clearly shows that PPT can be detected in vivo with an easy, noninvasive scintillation camera method.

Topics: Animals; Blood Platelets; Endotoxins; Escherichia coli Infections; Indium; Lung; Organometallic Compounds; Oxyquinoline; Platelet Count; Rabbits; Radioisotopes; Radionuclide Imaging; Scintillation Counting; Shock, Septic