Journal of Cerebral Blood Flow & Metabolism,
Journal Year:
1989,
Volume and Issue:
9(5), P. 589 - 596
Published: Oct. 1, 1989
Laser-Doppler
flowmetry
(LDF),
a
new
method
allowing
instantaneous,
continuous,
and
noninvasive
measurements
of
microcirculatory
blood
flow
in
small
tissue
sample,
was
evaluated
for
its
accuracy
monitoring
regional
cerebral
(rCBF)
the
cortical
microcirculation
after
focal
ischemia.
Wistar
spontaneously
hypertensive
rats
(SHR,
n
=
19)
were
subjected
to
permanent
occlusion
middle
common
carotid
arteries.
Absolute
rCBF
sample
ischemic
hemisphere
measured
autoradiographically
with
[
14
C]iodoantipyrine
as
tracer
compared
by
LDF.
Additionally,
percent
change
between
baseline
values
both
methods.
recorded
LDF
correlated
poorly
(
r
0.54)
measurements.
In
contrast,
readings
expressed
percentage
vs.
preocclusion
(relative
readings)
very
well
0.91)
We
conclude
that
does
not
provide
accurate
absolute
but
this
allows
changes
due
induction
Chronobiology International,
Journal Year:
1997,
Volume and Issue:
14(2), P. 185 - 204
Published: Jan. 1, 1997
Melatonin
has
clear
acute
and
delayed
effects
on
sleep
circadian
rhythms.
Decrements
in
core
temperature
alertness
have
been
found
at
different
times
of
day
following
low
pharmacological
physiological
doses
melatonin.
When
correctly
timed,
melatonin
induces
both
phase
advances
delays
the
system
humans.
timed
to
advance,
decrement
degree
shift
are
closely
related
dose.
In
simulation
field
studies,
can
alleviate
some
problems
shiftwork
jet
lag,
notably
enhancing
hastening
adaptation
rhythms
imposed
schedule.
Performance
changes
architecture
need
be
fully
evaluated.
The
optimization
dose
formulation
is
also
an
area
that
requires
further
work.
Whether
or
not
recently
developed
analogs
(72)
will
prove
more
less
useful
than
adapting
remains
seen.
If
incorrectly
potential
induce
deleterious
effects.
While
short-term
studies
indicate
it
very
toxicity,
there
no
long-term
safety
data.
All
reported
here
concern
healthy
adult
volunteers
use
a
preparation
licensed
for
human
experimental
available
named
patient
basis
prescription.
There
data
uncontrolled
preparations
over
counter
countries.
Its
pregnancy,
interaction
with
other
medications,
many
considerations
remain
addressed.
Thus,
while
well-controlled
conditions,
indiscriminate
unlicensed
advisable.
Chronobiology International,
Journal Year:
1989,
Volume and Issue:
6(1), P. 29 - 53
Published: Jan. 1, 1989
Different
types
of
masking
are
discussed
together
with
an
account
the
effect
that
sleep-wake
cycle
exerts
upon
circadian
rhythms
body
temperature
and
urinary
excretion.
The
relative
importance
to
several
components
differences
between
sleeping
wakefulness
then
assessed.Means
deal
problem
fall
into
two
major
categories.
These
attempt
minimise
effects
by
protocols
such
as
constant
routines
or
control
days,
mathematical
models
which
separate
results
obtained
in
presence
influences
endogenous
exogenous
components.
(The
extent
can
render
component
a
rhythm
impure
reflection
internal
oscillator
is
considered
also.)
different
techniques
compared
respect
their
usefulness
assumptions.Finally,
brief
speculation
given
masking.
Chronobiology International,
Journal Year:
2000,
Volume and Issue:
17(3), P. 245 - 259
Published: Jan. 1, 2000
The
suprachiasmatic
nucleus
(SCN)
of
the
hypothalamus
is
implicated
in
timing
a
wide
variety
circadian
processes.
Since
environmental
light-dark
cycle
main
zeitgeber
for
many
rhythms,
photic
information
may
have
synchronizing
effect
on
endogenous
clock
SCN
by
inducing
periodic
changes
biological
activity
certain
groups
neurons.
By
studying
brains
obtained
at
autopsy
human
subjects,
marked
diurnal
oscillations
were
observed
neuropeptide
content
SCN.
Vasopressin,
example,
one
most
abundant
peptides
SCN,
exhibited
rhythm,
with
low
values
night
and
peak
during
early
morning.
However,
advancing
age,
these
fluctuations
deteriorated,
leading
to
disrupted
reduced
amplitude
elderly
people.
These
findings
suggest
that
synthesis
some
exhibits
an
rhythmicity,
temporal
organization
rhythms
becomes
progressively
disturbed
senescence.