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Biomedical subjects

B R Andersen

Publications and source records attributed to B R Andersen.

At least 73 records · Page 4Linked to original sources
PubMed1977

Organ distribution of canine leukocytes labeled with 99mTc-sulfur colloid.

Previous reports have shown that scintigraphic localization of acute inflammation can be achieved using autologous leukocytes labeled in vitro with 99mTc-sulfur colloid (TcSC). The technique is limited, however, by a marked accumulation of radioactivity in the lungs and liver of normal animals. A modified procedure was developed using preparations of TcSC of small particle size to label blood leukocytes in vitro. Markedly decreased levels of lung and liver radioactivity and elevated levels of blood radioactivity were found after intravenous infusion of autologous canine leukocytes labeled by this method. These leukocytes could be used to image areas of acute inflammation resulting from induction of septic or sterile venous thrombi.

Animals↗
PubMed1976

Value of granulocyte examination for bacteria.

Granulocytes from patients with suspected bacteremia and from dogs with staphylococcal bacteremia were examined by light microscopy for the presence of intracellular inclusions that resembled microorganisms. Quantitative blood cultures were done at the same time. Few granulocytic inclusions were observed during a two-hour screening period even when high levels of bacteremia were present. There was no correlation between the number of inclusions and the quantitative blood culture data. The inclusions appear to be artifacts of the staining procedure. This technique has questionable value in the diagnosis of bacteremia and may be misleading.

Animals↗
PubMed1976

Evaluation of type-specific and non-type-specific pseudomonas vaccine for treatment of pseudomonas sepsis during granulocytopenia.

The protective role of serotype-specific and non-type-specific active immunity against Pseudomonas aeruginosa infection was assessed in granulocytopenic dogs. Dogs were preimmunized with either specific serotype 6 vaccine (SI) or nonspecific serotype 3 vaccine (NSI) and challenged intravenously with 10(7) viable serotype 6 P. aeruginosa during granulocytopenia. Control dogs (C) having insignificant anti-pseudomonas antibody levels were also tested. Results showed: (i) significant increase in survival of SI dogs (P less than 0.05) compared to C and NSI dogs, with no significant difference between C and NSI animals; (ii) lower febrile responses in SI dogs; and (iii) markedly reduced bacteremia in SI dogs compared to C and NSI animals. SI dog sera from survivor animals did not kill the infecting pseudomonas strain in vitro. The study demonstrated that type-specific immunity to P. aeruginosa induced by active immunization is effective in protection against pseudomonas during granulocytopenia and that non-type-specific immunity offers no cross-reactive protection. The findings suggest that the reticuloendothelial system in conjunction with specific immunity constitute an important defense against pseudomonas infections.

Agranulocytosis↗
PubMed1976

Passive immunity against pseudomonas sepsis during granulocytopenia.

Specific passive immunity against Pseudomonas aeruginosa sepsis was assessed in granulocytopenic dogs. Dogs were infused with either normal or antipseudomonas immune plasma 24 h before pseudomonas challenge. They were challenged intravenously with 10(7) serotype 6 P. aeruginosa during granulocytopenia. Treatment was evaluated by observation of survival periods, febrile responses, type 6 pseudomonas antibody titers, and quantitative cultures of blood and tissues. The results demonstrated that passively immunized dogs did not survive infection. Both normal-plasma and immune-plasma recipients had bacteremia at death, with median values of 980 and 470 pseudomonas per ml of blood, respectively. All dogs had marked febrile responses 24 h after pseudomonas challenge and had high concentrations of pseudomonas in their lung tissue at death, with median values of 10(8) pseudomonas per g of wet tissue weight. After plasma infusion, immune-plasma recipients had high concentrations of anti-pseudomonas antibody, with total antibody titers ranging from 256 to 1,024 and a median value of 1,024. These titers were comparable to titers attained in a previous study from our laboratory using active immunization with pseudomonas lipopolysaccharide vaccine, where the median total anti-pseudomonas antibody titer was 2,048. Actively immunized animals, however, were significantly protected against pseudomonas sepsis and had prolonged survival periods and prevention of bacteremia. The present study demonstrates that circulating type-specific antibody is not solely responsible for the protection afforded to granulocytopenic dogs actively immunized against pseudomonas.

Agranulocytosis↗
PubMed1976

Effect of bone marrow suppression on granulocyte opsonin levels.

Levels of serum opsonin for neutrophilic granulocytes were measured in dogs made neutropenic by cyclophosphamide administration. Heat-labile opsonin became elevated within 24 hr following cyclophosphamide (P less than 0.005) and remained elevated over the 4-5 day period of observation (P less than 0.005). In contrast, heat stable opsonin was not significantly effected. Bone marrow suppression by X-ray and busulfan also caused serum opsonin levels to increase. Changes in the levels of IgG, C3, and total hemolytic complement during the course of bone marrow suppression did not correlate with the granulocyte opsonin levels. These findings suggest that serum granulocyte opsonin levels respond to bone marrow suppression and may provide an improved environment for the function of transfused granulocytes.

Agranulocytosis↗
PubMed1976

Combined pre-immunization and granulocyte transfusion therapy for treatment of pseudomonas septicemia in neutropenic dogs.

An experimental model was designed to evaluate a combined protocol of active immunization and granulocyte transfusions for treatment of Pseudomonas aeruginosa sepsis in the neutropenic host. One member of a pair of dogs was immunized with P. aeruginosa vaccine. Both dogs were then rendered transiently neutropenic with a single intravenous dose of cyclophosphamide (40 mg. per kilogram) and challenged with an intravenous inoculum of P. aeruginosa. Twenty-four and 48 hours after pseudomonas challenge each animal received granulocyte transfusions. Effectiveness of therapy was evaluated by observation of survival time, febrile response, and quantitative blood cultures. Results showed a significant increase in the survival period (P is less than 0.05), a lower febrile response (P is less than 0.025), negative blood cultures, and a greater recovery rate in the immune group. Immune dogs that died had negative blood cultures or less than or equal to 10 pseudomonas per milliliter of blood despite the presence of P. aeruginosa in tissues. In contrast, control dogs had septic deaths within 67 hours of pseudomonas challenge, marked febrile responses with 24 hours of infection, and positive blood cultures with 4,000 to 25,800 pseudomonas per milliliter of blood. These data show that combined therapy with immunization and granulocyte transfusions is effective in reducing the severity of P. aeruginosa infection and in preventing bacteremia during periods of leukopenia.

Agranulocytosis↗
PubMed1975

Labeling of phagocytes from human blood with 99mTc-sulfur colloid.

Experments in this report have shown that peripheral blood leukocytes can be readily labeled with 99mTc-sulfur colloid during in vitro incubation. Phagocytic cells were preferentially labeled by this method. Labeling was enhanced in the presence of normal serum. The data suggest that labeling was accomplished by phagocytosis of the radiocolloid. Labeled granulocytes responded normally to chemotactic stimuli and excluded trypan blue dye normally. Buffy coat cells from 50 ml of peripheral blood could be labeled with 8 mCi of 99mTc after incubation with 20 mCi of TcSC. This report offers a method by which phagocytic cells can be selectively labeled with 99mTc in amounts suitable for scintillation scanning.

Chemotaxis↗
PubMed1975

Inflammatory lesions localized with technetium Tc 99m-labeled leukocytes.

Canine leukocytes were labeled with a gamma-ray emitting isotope by permitting them to phagocytize technetium Tc 99m sulfur colloid particles in vitro and removing the unphagocytized particles by washing the cells. The labeled cells were reinfused intravenously into the donor dogs. Scintigraphic scans were performed 4 and 24 hours following the leukocyte infusion. In animals with sterile and infected intramuscular abscesses and pulmonary infections, it was possible to localize the lesions by scintigraphic scanning four hours following administration of labeled leukocytes. In one experiment, a positive scan was observed 24 hours after the leukocyte infusion. It was also shown that labeled leukocytes tend to concentrate in abscess fluid. These results suggest that technetium Tc 99m sulfur colloid-labeled leukocytes may be a useful diagnostic tool in localizing abscesses and inflammatory lesions in humans.

Abscess↗
PubMed1974

Streptolysin O inhibition of neutrophil chemotaxis and mobility: nonimmune phenomenon with species specificity.

The effects of streptolysin O (SO) (1 to 4 hemolytic units) on the mobility of neutrophilic leukocytes from humans, baboons, sheep, and rabbits were compared. After SO treatment, chemotaxis and random mobility of human neutrophils were markedly suppressed, baboon and sheep neutrophils were partially suppressed, and rabbit neutrophils were unaffected and demonstrated normal chemotaxis and mobility. The amounts of SO used in the mobility studies caused no leukocyte lysis or trypan blue uptake by human, baboon, or sheep cells, and minimal lysis or trypan blue uptake by rabbit cells. The possible involvement of immune mediators in the observed inhibition of human neutrophils was considered and excluded by the following studies. White blood cells from humans with humoral or cellular immune deficiencies responded in a manner similar to normal human cells; supernatant solutions from SO-treated human white blood cells did not contain a chemotactic suppressor; preincubation of SO with cholesterol (an inhibitor of SO hemolytic activity) caused loss of the chemotactic suppressive effect of the toxin on human leukocytes; and leukocytes from rabbits preimmunized with SO remained refractory to chemotactic suppression.

Agammaglobulinemia↗