402 research outputs found
Fiber Optic Spectroscopy for the Optimization of Photodynamic Therapy
__Abstract__
Photodynamic
therapy
(PDT)
is
a
treatment
modality
for
cancer
and
premalignant
lesions
that
utilizes
a
photoactive
drug,
the
photosensitizer,
in
combination
with
light.
PDT
has
become
the
treatment
of
choice
for
various
malignancies.
Furthermore,
PDT
is
under
investigation
as
a
potential
(palliative)
treatment
in
situations
where
the
possibilities
of
chemo-
and
radiotherapy
are
limited
or
exhausted.
Since
both
photosensitizer
and
light
have
to
be
present
to
cause
tissue
damage,
selective
damage
to
the
lesion
can
be
achieved
by
controlling
the
presence
of
either
one
of
them
to
the
treatment
area.
Selective
damage
can
be
reached
by
i)
choosing
a
photosensitizer
that
is
mainly
present
in
the
lesion,
or
ii)
preventing
normal
tissue
from
being
illuminated.
However,
the
success
of
PDT
in
reducing/removing
(pre-‐)malignant
lesions
has
been
variable.
Treatment
efficacy
can
range
form
non-‐observable
effects
to
severe
damage
to
normal
tissue.
Considering
the
complexity
of
both
the
execution
of
the
treatment
and
damage
pathways
involved
in
PDT,
some
variability
in
treatment
efficacy
is
not
unexpected.
However,
given
the
fact
that
clinical
applications
of
PDT
that
have
proved
successful
remain
small
in
number,
more
work
is
necessary
to
optimize
therapeutic
efficacy
Transforming operating rooms: factors for successful implementations of new medical equipment
Operating Rooms (OR’s) are complex, high tech environments with extensive use of medical equipment and information technology. The implementation of new medical equipment with the aim to increase safety, improve patient outcomes or to improve efficiency may initially cause disruptions in the OR, which influence its success. Between and within hospitals the implementation of medical equipment varies and a generic implementation model omits. The aim of this study is to identify factors for successful implementations according to surgical supportive staff. Results are compared with findings from other published studies. In total 90 out of 235 surveys were returned (38%). Respondents, scrub nurses and circulating nurses, indicate that implementation and integration of new medical equipment in current activities and ICT systems remain a challenge. In this study we identified the following factors: a coherent and holistic implementation approach; integration of medical equipment in processes, systems and organization; knowledge and skill development and effective communication during the implementation process
Comparison of immune responses in parenteral FaeG DNA primed pigs boosted orally with F4 protein or reimmunized with the DNA vaccine
A
Extraction of Intrinsic Fluorescence from Single Fiber Fluorescence Measurements on a Turbid Medium: Experimental Validation
Abstract The detailed mechanisms associated with the influence of scattering and absorption properties on the fluorescence intensity sampled by a single optical fiber have recently been elucidated based on Monte Carlo simulated data. Here we develop an experimental single fiber fluorescence (SFF) spectroscopy setup and validate the Monte Carlo data and semi-empirical model equation that describes the SFF signal as a function of scattering. We present a calibration procedure that corrects the SFF signal for all system-related, wavelength dependent transmission efficiencies to yield an absolute value of intrinsic fluorescence. The validity of the Monte Carlo data and semi-empirical model is demonstrated using a set of fluorescent phantoms with varying concentrations of Intralipid to vary the scattering properties, yielding a wide range of reduced scattering coefficients (μ′s = 0–7 mm −1). We also introduce a small modification to the model to account for the case of μ′s = 0 mm −1 and show its relation to the experimental, simulated and theoretically calculated value of SFF intensity in the absence of scattering. Finally, we show that our method is also accurate in the presence of absorbers by performing measurements on phantoms containing red blood cells and correcting for their absorption properties
Comparison of immune responses in parenteral FaeG DNA primed pigs boosted orally with F4 protein or reimmunized with the DNA vaccine
Maternal immunity enhances systemic recall immune responses upon oral immunization of piglets with F4 fimbriae
F4 enterotoxigenic Escherichia coli (ETEC) cause diarrhoea and mortality in piglets leading to severe economic losses. Oral immunization of piglets with F4 fimbriae induces a protective intestinal immune response evidenced by
an F4-specific serum and intestinal IgA response. However, successful oral immunization of pigs with F4 fimbriae in the presence of maternal immunity has not been demonstrated yet. In the present study we aimed to evaluate the effect of maternal immunity on the induction of a systemic immune response upon oral immunization of piglets. Whereas F4-specific IgG and IgA could be induced by oral immunization of pigs without maternal antibodies
and by intramuscular immunization of pigs with maternal antibodies, no such response was seen in the orally immunized animals with maternal antibodies. Since maternal antibodies can mask an antibody response, we also looked by ELIspot assays for circulating F4-specific antibody secreting cells (ASCs). Enumerating the F4-specific ASCs within the circulating peripheral blood mononuclear cells, and the number of F4-specific IgA ASCs within the circulating IgA+ B-cells revealed an F4-specific immune response in the orally immunized animals with maternal antibodies. Interestingly, results suggest a more robust IgA booster response by oral immunization of pigs with than without maternal antibodies. These results demonstrate that oral immunization of piglets with F4-specific maternal antibodies is feasible and that these maternal antibodies seem to enhance the secondary systemic immune response. Furthermore, our ELIspot assay on enriched IgA+ B-cells could be used as a screening procedure to optimize mucosal immunization protocols in pigs with maternal immunity
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