Preface - Ous-research.no

Surgical Intensive Care Medicine
tively. Plasma levels of several cytokines will be measured
by ELISA (multiplex). Furthermore, blood was incubated in
a whole blood model. The blood was first anticoagulated
with heparin (25 U/mL) and incubated at 37°C with slow
rotation in the presence of either Lipopolysaccaride (10 ng/
mL blood), Peptidoglycan isolated form Staphylococcus
aureus (1 µg/mL blood) or saline, respectively. At 0,1,4,6,12
and 24 h, plasma was obtained by centrifugation and stored
at -70°C. Levels of cytokines will be measured to further
assess inflammatory responses after laparoscopic and open
surgery.
Clinical data are recorded prospectively during hospital stay
and at follow-ups 6, 12 and 24 months postoperatively.
Determination of P.aeruginosa virulence .
Pseudomonas aeruginosa (PAER) is an opportunistic bacterium
which seldom cause disease in healthy individuals. But,
the increasing number of immunocompromised individuals
has provoked a rise in PAER infections. In vitro determination
of PAER virulence is complicated, and the current gold
standard is a C. elegans killing assay. The killing assay measures
relative virulence of PAER serotypes, but a major drawback
is that it’s time consuming and resource demanding.
In collaboration with Department of Infection Prevention
headed by Egil Lingaas, MD, we investigate markers of the
innate immune-response as an improved alternative to the
established assay.
Clinical isolates of PAER from patients with bacteremia were
subjected to comparative evaluation in both the established
killing assay and a well-established human whole blood
model.
Due to variation in individual response in human whole
blood model we decided to use a cellular model: THP-1 cell
line. The viability assay confirmed the differences in virulence
of the strains tested on C. elegans, whereas the highly
virulent strains for C. elegans reduced significantly the
viability of the cells during the assay. The expression of host
factors of innate immunological response is currently being
investigated to establish a better understanding of host/
pathogen interactions and to identify host factors mediating
susceptibility or resistance to virulent PAER isolates
Studies on possible effects of a newly developed hemapheresis
filter (TM100) on inflammatory mediators and
hemodynamic parameters during experimental endotoxinemia
in pigs.
Therapy in sepsis is still greatly discussed due to a high mortality.
Lipopolysaccaride (LPS) is a main initiator of cascade
chain reactions during gram negative sepsis that may lead
to multi organ failure, circulatory collapse and eventually
death. There are some few publications concerning possible
positive effects using hemofiltration in humans during
severe infections. We have started to test a newly developed
hemofiltration filter (TM 100) in anaesthetized pigs during
ongoing LPS infusion. Twelve heparinised animals have
been used during 2010 to look for an optimal filter content
and experimental model. The filter device was placed in the
inferior caval vein. We have searched for criteria for possible
effects on different parameters.
Results so far have revealed a systemic reduction in the
TNF-α concentration by 30%. During ongoing hemofiltration
an initial drop in systemic blood pressure was detected
but could be reversed after intravenous saline. Further studies
comparing effects of different hemofiltration systems
are planned.
The C. elegans killing assays optimized by Reza Assalkhou,
PhD, (Dep. of Infection Prevention) showed that this assay is
highly reproducible and can differentiate between strains of
PAER with high, moderate and low virulence respectively.
The ex vivo whole blood model to study the inflammatory
response by measurment of the cytokine production of
leukocytes was used. Testing blood from 3 different persons
clearly indicated the variation in regulation of cytokines
production between these persons in response to bacterial
infection.( IL (Beta, Ra, 2, 2R, 4, 6, 7, 8, 10, 12, 15), TNF-Alpha,
INF-Alpha, INF-Y, GM-CSF, MIP (1Alpha & 1Beta), IP-10, MIG,
Eotaxin, RANTES, MCP-1, G-CSF, FGF basic, HGF, VEGF).
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