bluuebunny/crossref_metadata_2025 huggingface dataset:
Pseudomonas syringae
manipulates systemic plant defenses against pathogens and herbivores
Authors: Cui Jianping , Bahrami Adam K. , Pringle Elizabeth G. , Hernandez-Guzman Gustavo , Bender Carol L. , Pierce Naomi E. , Ausubel Frederick M.
Published: January 2005

Many pathogens are virulent because they specifically interfere with host defense responses and therefore can proliferate. Here, we report that virulent strains of the bacterial phytopathogen
Pseudomonas syringae
induce systemic susceptibility to secondary
P. syringae
infection in the host plant
Arabidopsis thaliana
. This systemic induced susceptibility (SIS) is in direct contrast to the well studied avirulence/
R
gene-dependent resistance response known as the hypersensitive response that elicits systemic acquired resistance. We show that
P. syringae
-elicited SIS is caused by the production of coronatine (COR), a pathogen-derived functional and structural mimic of the phytohormone jasmonic acid (JA). These data suggest that SIS may be a consequence of the previously described mutually antagonistic interaction between the salicylic acid and JA signaling pathways. Virulent
P. syringae
also has the potential to induce net systemic susceptibility to herbivory by an insect (
Trichoplusia ni
, cabbage looper), but this susceptibility is not caused by COR. Rather, consistent with its role as a JA mimic, COR induces systemic resistance to
T. ni
. These data highlight the complexity of defense signaling interactions among plants, pathogens, and herbivores.
A fluorescent probe designed for studying protein conformational change
Authors: Cohen Bruce E. , Pralle Arnd , Yao XiaoJie , Swaminath Gayathri , Gandhi Chris S. , Jan Yuh Nung , Kobilka Brian K. , Isacoff Ehud Y. , Jan Lily Y.
Published: January 2005

The usefulness of fluorescence in studying protein motions derives from its sensitivity, kinetic resolution, and compatibility with both live cells and physiological assays. Recent advances in microscopy and membrane protein purification have permitted the observation of fluorescence changes that accompany the functional transitions of complex eukaryotic membrane proteins. These techniques rely on probes that can clearly report the environmental changes of specific residues, but most commonly available side-chain-reactive probes are not well suited for this purpose. Here, we introduce a red Cys-reactive probe, aminophenoxazone maleimide (APM), designed with improved chemical and spectral properties for reporting protein conformational change. APM is compact, uncharged, and has a short linker between probe and protein, all of which ensure that it can closely track the motions of the side chain to which it is attached. It undergoes large polarity-dependent changes in Stokes shift, as well as large bathochromic shifts in both excitation maximum (from 521 nm in toluene to 598 nm in water) and emission maximum (580 nm to 633 nm). These polarity-dependent spectral changes offer a potentially simple means of relating fluorescence to local structure and motion, although they are partially offset by some complicating factors in APM fluorescence. We find that, like a rhodamine maleimide, APM senses the conformational changes underlying voltage sensing in the Shaker potassium channel, and it is superior at a site that shows limited reactivity to the rhodamine. The spectral characteristics of APM can also report subtle differences between aqueous positions in purified preparations of the β2adrenergic receptor.
Preferential Phosphorylation of R-domain Serine 768 Dampens Activation of CFTR Channels by PKA
Authors: Csanády László , Seto-Young Donna , Chan Kim W. , Cenciarelli Cristina , Angel Benjamin B. , Qin Jun , McLachlin Derek T. , Krutchinsky Andrew N. , Chait Brian T. , Nairn Angus C. , Gadsby David C.
Published: January 2005

CFTR (cystic fibrosis transmembrane conductance regulator), the protein whose dysfunction causes cystic fibrosis, is a chloride ion channel whose gating is controlled by interactions of MgATP with CFTR's two cytoplasmic nucleotide binding domains, but only after several serines in CFTR's regulatory (R) domain have been phosphorylated by cAMP-dependent protein kinase (PKA). Whereas eight R-domain serines have previously been shown to be phosphorylated in purified CFTR, it is not known how individual phosphoserines regulate channel gating, although two of them, at positions 737 and 768, have been suggested to be inhibitory. Here we show, using mass spectrometric analysis, that Ser 768 is the first site phosphorylated in purified R-domain protein, and that it and five other R-domain sites are already phosphorylated in resting Xenopus oocytes expressing wild-type (WT) human epithelial CFTR. The WT channels have lower activity than S768A channels (with Ser 768 mutated to Ala) in resting oocytes, confirming the inhibitory influence of phosphoserine 768. In excised patches exposed to a range of PKA concentrations, the open probability (Po) of mutant S768A channels exceeded that of WT CFTR channels at all [PKA], and the half-maximally activating [PKA] for WT channels was twice that for S768A channels. As the open burst duration of S768A CFTR channels was almost double that of WT channels, at both low (55 nM) and high (550 nM) [PKA], we conclude that the principal mechanism by which phosphoserine 768 inhibits WT CFTR is by hastening the termination of open channel bursts. The right-shifted Po-[PKA] curve of WT channels might explain their slower activation, compared with S768A channels, at low [PKA]. The finding that phosphorylation kinetics of WT or S768A R-domain peptides were similar provides no support for an alternative explanation, that early phosphorylation of Ser 768 in WT CFTR might also impair subsequent phosphorylation of stimulatory R-domain serines. The observed reduced sensitivity to activation by [PKA] imparted by Ser 768 might serve to ensure activation of WT CFTR by strong stimuli while dampening responses to weak signals.
Ca2+- and Volume-sensitive Chloride Currents Are Differentially Regulated by Agonists and Store-operated Ca2+ Entry
Authors: Zholos Alexander , Beck Benjamin , Sydorenko Vadym , Lemonnier Loïc , Bordat Pascal , Prevarskaya Natalia , Skryma Roman
Published: January 2005

Using patch-clamp and calcium imaging techniques, we characterized the effects of ATP and histamine on human keratinocytes. In the HaCaT cell line, both receptor agonists induced a transient elevation of [Ca2+]i in a Ca2+-free medium followed by a secondary [Ca2+]i rise upon Ca2+ readmission due to store-operated calcium entry (SOCE). In voltage-clamped cells, agonists activated two kinetically distinct currents, which showed differing voltage dependences and were identified as Ca2+-activated (ICl(Ca)) and volume-regulated (ICl, swell) chloride currents. NPPB and DIDS more efficiently inhibited ICl(Ca) and ICl, swell, respectively. Cell swelling caused by hypotonic solution invariably activated ICl, swell while regulatory volume decrease occurred in intact cells, as was found in flow cytometry experiments. The PLC inhibitor U-73122 blocked both agonist- and cell swelling–induced ICl, swell, while its inactive analogue U-73343 had no effect. ICl(Ca) could be activated by cytoplasmic calcium increase due to thapsigargin (TG)-induced SOCE as well as by buffering [Ca2+]i in the pipette solution at 500 nM. In contrast, ICl, swell could be directly activated by 1-oleoyl-2-acetyl-sn-glycerol (OAG), a cell-permeable DAG analogue, but neither by InsP3 infusion nor by the cytoplasmic calcium increase. PKC also had no role in its regulation. Agonists, OAG, and cell swelling induced ICl, swell in a nonadditive manner, suggesting their convergence on a common pathway. ICl, swell and ICl(Ca) showed only a limited overlap (i.e., simultaneous activation), although various maneuvers were able to induce these currents sequentially in the same cell. TG-induced SOCE strongly potentiated ICl(Ca), but abolished ICl, swell, thereby providing a clue for this paradox. Thus, we have established for the first time using a keratinocyte model that ICl, swell can be physiologically activated under isotonic conditions by receptors coupled to the phosphoinositide pathway. These results also suggest a novel function for SOCE, which can operate as a “selection” switch between closely localized channels.
Properly 3-realizable groups
Authors: Ayala R. , Cárdenas M. , Lasheras F. , Quintero A.
Published: January 2005

A finitely presented group

G
G

is said to be properly

3
3

-realizable if there exists a compact

2
2

-polyhedron

K
K

with

π
1

(
K
)
≅
G

\pi _1(K) \cong G

and whose universal cover

K
~

\tilde {K}

has the proper homotopy type of a (p.l.)

3
3

-manifold with boundary. In this paper we show that, after taking wedge with a

2
2

-sphere, this property does not depend on the choice of the compact

2
2

-polyhedron

K
K

with

π
1

(
K
)
≅
G

\pi _1(K) \cong G

. We also show that (i) all

0
0

-ended and

2
2

-ended groups are properly

3
3

-realizable, and (ii) the class of properly

3
3

-realizable groups is closed under amalgamated free products (HNN-extensions) over a finite cyclic group (as a step towards proving that

∞
\infty

-ended groups are properly

3
3

-realizable, assuming

1
1

-ended groups are).
Multipliers of weighted spaces and reflexivity property
Authors: Dussau Xavier
Published: January 2005

We prove for some translation-invariant weighted spaces

E
E

the following characterization:

T
T

is a multiplier of

E
E

if and only if

T
T

leaves invariant every translation-invariant subspace of

E
E

. This result is equivalent with the reflexivity of the multiplier algebra of

E
E

.
Coverings by convex bodies and inscribed balls
Authors: Kadets Vladimir
Published: January 2005

Let

H
H

be a Hilbert space. For a closed convex body

A
A

denote by

r
(
A
)

r(A)

the supremum of the radiuses of balls contained in

A
A

. We prove that

∑

n
=
1

∞

r
(

A
n

)
≥
r
(
A
)

\sum _{n=1}^\infty r(A_n) \ge r(A)

for every covering of a convex closed body

A
⊂
H

A \subset H

by a sequence of convex closed bodies

A
n

A_n

,

n
∈

N

n \in \mathbb {N}

. It looks like this fact is new even for triangles in a 2-dimensional space.
The Hausmann-Weinberger 4–manifold invariant of abelian groups
Authors: Kirk Paul , Livingston Charles
Published: January 2005

The Hausmann-Weinberger invariant of a group

G
G

is the minimal Euler characteristic of a closed orientable 4–manifold

M
M

with fundamental group

G
G

. We compute this invariant for finitely generated free abelian groups and estimate the invariant for all finitely generated abelian groups.
Spectrally bounded 𝜙–derivations on Banach algebras
Authors: Lee Tsiu-Kwen , Liu Cheng-Kai
Published: January 2005

Applying the density theorem on algebras with

ϕ
\phi

–derivations, we show that if a

ϕ
\phi

–derivation

δ
\delta

of a unital Banach algebra

A
A

is spectrally bounded, then

[
δ
(
A
)
,
A
]
⊆
rad
(
A
)

[\delta (A), A]\subseteq \text {rad}(A)

. Also,

δ
(
A
)
⊆
rad
(
A
)

\delta (A)\subseteq \text {rad}(A)

if and only if

sup
{
r
(

z

−
1

δ
(
z
)
)
∣
z
∈
A
 
is invertible
}
>
∞

\text {sup}\{r(z^{-1}\delta (z))\mid z\in A\ \text {is invertible}\}>\infty

, where

r
(
a
)

r(a)

denotes the spectral radius of

a
∈
A

a\in A

.
Duals and envelopes of some Hardy-Lorentz spaces
Authors: Lengfield Marc
Published: January 2005

For

0
>
p
>
1

0>p>1

we describe the dual spaces and Banach envelopes of the spaces

H

p
,
q

H^{p,q}

for finite values of

q
q

and for

H

0

p
,
∞

H_{0}^{p,\infty }

, the closure of the polynomials in

H

p
,
∞

H^{p,\infty }

. In addition, we determine the

s
s

-Banach envelopes for the spaces

H

p
,
q

H^{p,q}

in the cases

0
>
q
>
p
>
s
≤
1

0>q>p>s\leq 1

and

0
>
q
>
p
≤
s
≤
1

0>q>p\leq s\leq 1

.
Some characterizations of minimally thin sets in a cylinder and Beurling-Dahlberg-Sjögren type theorems
Authors: Miyamoto Ikuko , Yanagishita Minoru
Published: January 2005

This paper shows that some characterizations of minimally thin sets connected with a domain having smooth boundary and a half-space in particular can also be given for a minimally thin set at infinity of a cylinder.
Symmetrized Chebyshev polynomials
Authors: Rivin Igor
Published: January 2005

We define a class of multivariate Laurent polynomials closely related to Chebyshev polynomials and prove the simple but somewhat surprising (in view of the fact that the signs of the coefficients of the Chebyshev polynomials themselves alternate) result that their coefficients are non-negative. As a corollary we find that

T
n

(
c
cos
⁡
θ
)

T_n(c \cos \theta )

and

U
n

(
c
cos
⁡
θ
)

U_n(c \cos \theta )

are positive definite functions. We further show that a Central Limit Theorem holds for the coefficients of our polynomials.
Fourier transforms having only real zeros
Authors: Cardon David
Published: January 2005

Let

G
(
z
)

G(z)

be a real entire function of order less than

2
2

with only real zeros. Then we classify certain distribution functions

F
F

such that the Fourier transform
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper H left-parenthesis z right-parenthesis equals integral Subscript negative normal infinity Superscript normal infinity Baseline upper G left-parenthesis i t right-parenthesis e Superscript i z t Baseline d upper F left-parenthesis t right-parenthesis">

H
(
z
)
=

∫

−
∞

∞

G
(
i
t
)

e

i
z
t

d
F
(
t
)

H(z)=\int _{-\infty }^{\infty }G(it)e^{izt}\,dF(t)

has only real zeros.
Logarithmic Comparison Theorem and some Euler homogeneous free divisors
Authors: Castro-Jiménez F. , Ucha-Enríquez J.
Published: January 2005

Let

D
,
x

D,x

be a free divisor germ in a complex manifold

X
X

of dimension

n
>
2

n>2

. It is an open problem to find out which are the properties required for

D
,
x

D,x

to satisfy the so-called Logarithmic Comparison Theorem (LCT), that is, when the complex of logarithmic differential forms computes the cohomology of the complement of

D
,
x

D,x

. We give a family of Euler homogeneous free divisors which, somewhat unexpectedly, does not satisfy the LCT.
A vectorial inverse nodal problem
Authors: Cheng Yan-Hsiou , Shieh Chung-Tsun , Law C.
Published: January 2005

Consider the vectorial Sturm-Liouville problem:
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="StartLayout Enlarged left-brace 1st Row minus bold y left-parenthesis x right-parenthesis plus upper P left-parenthesis x right-parenthesis bold y left-parenthesis x right-parenthesis equals lamda upper I Subscript d Baseline bold y left-parenthesis x right-parenthesis upper A bold y left-parenthesis 0 right-parenthesis plus upper I Subscript d Baseline bold y prime left-parenthesis 0 right-parenthesis equals bold 0 upper B bold y left-parenthesis 1 right-parenthesis plus upper I Subscript d Baseline bold y prime left-parenthesis 1 right-parenthesis equals bold 0 EndLayout">

{

−

y

(
x
)
+
P
(
x
)

y

(
x
)
=
λ

I

d

y

(
x
)
A

y

(
0
)
+

I

d

y

′

(
0
)
=

0

B

y

(
1
)
+

I

d

y

′

(
1
)
=

0

\left \{\begin {array}{l} -{\mathbf y}(x)+P(x){\mathbf y}(x) = \lambda I_{d}{\mathbf y}(x) A{\mathbf y}(0)+I_{d}{\mathbf y}’(0)={\mathbf 0} B{\mathbf y}(1)+I_{d}{\mathbf y}’(1)={\mathbf 0} \end {array}\right .

\]
where

P
(
x
)
=
[

p

i
j

(
x
)

]

i
,
j
=
1

d

P(x)=[p_{ij}(x)]_{i,j=1}^{d}

is a continuous symmetric matrix-valued function defined on

[
0
,
1
]

[0,1]

, and

A
A

and

B
B

are

d
×
d

d\times d

real symmetric matrices. An eigenfunction

y

(
x
)

{\mathbf y}(x)

of the above problem is said to be of type (CZ) if any isolated zero of its component is a nodal point of

y

(
x
)

{\mathbf y}(x)

. We show that when

d
=
2

d=2

, there are infinitely many eigenfunctions of type (CZ) if and only if

(
P
(
x
)
,
A
,
B
)

(P(x), A, B)

are simultaneously diagonalizable. This indicates that

(
P
(
x
)
,
A
,
B
)

(P(x), A, B)

can be reconstructed when all except a finite number of eigenfunctions are of type (CZ). The results supplement a theorem proved by Shen-Shieh (the second author) for Dirichlet boundary conditions. The proof depends on an eigenvalue estimate, which seems to be of independent interest.
Weak boundedness theorems for canonically fibered Gorenstein minimal 3-folds
Authors: Chen Meng
Published: January 2005

Let

X
X

be a Gorenstein minimal projective 3-fold with at worst locally factorial terminal singularities. Suppose the canonical map is of fiber type. Denote by

F
F

a smooth model of a generic irreducible element in fibers of

ϕ
1

\phi _1

, and so

F
F

is a curve or a smooth surface. The main result is that there is a computable constant

K
K

independent of

X
X

such that

g
(
F
)
≤
647

g(F)\le 647

or

p
g

(
F
)
≤
38

p_g(F)\le 38

whenever

p
g

(
X
)
≥
K

p_g(X)\ge K

.
More on convexity numbers of closed sets in ℝⁿ
Authors: Geschke Stefan
Published: January 2005

The convexity number of a set

S
⊆

R

n

S\subseteq \mathbb R^n

is the least size of a family

F

\mathcal F

of convex sets with

⋃

F

=
S

\bigcup \mathcal F=S

.

S
S

is countably convex if its convexity number is countable. Otherwise

S
S

is uncountably convex. Uncountably convex closed sets in

R

n

\mathbb R^n

have been studied recently by Geschke, Kubiś, Kojman and Schipperus. Their line of research is continued in the present article. We show that for all

n
≥
2

n\geq 2

, it is consistent that there is an uncountably convex closed set

S
⊆

R

n
+
1

S\subseteq \mathbb R^{n+1}

whose convexity number is strictly smaller than all convexity numbers of uncountably convex subsets of

R

n

\mathbb R^n

. Moreover, we construct a closed set

S
⊆

R

3

S\subseteq \mathbb R^3

whose convexity number is

2

ℵ
0

2^{\aleph _0}

and that has no uncountable

k
k

-clique for any

k
>
1

k>1

. Here

C
⊆
S

C\subseteq S

is a

k
k

-clique if the convex hull of no

k
k

-element subset of

C
C

is included in

S
S

. Our example shows that the main result of the above-named authors, a closed set

S
⊆

R

2

S\subseteq \mathbb R^2

either has a perfect

3
3

-clique or the convexity number of

S
S

is

>

2

ℵ
0

>2^{\aleph _0}

in some forcing extension of the universe, cannot be extended to higher dimensions.
Semi-continuity of metric projections in ℓ_{∞}-direct sums
Authors: Indumathi V.
Published: January 2005

Let

Y
Y

be a proximinal subspace of finite codimension of

c
0

c_0

. We show that

Y
Y

is proximinal in

ℓ
∞

\ell _\infty

and the metric projection from

ℓ
∞

\ell _\infty

onto

Y
Y

is Hausdorff metric continuous. In particular, this implies that the metric projection from

ℓ
∞

\ell _\infty

onto

Y
Y

is both lower Hausdorff semi-continuous and upper Hausdorff semi-continuous.
Some remarks on an existence problem for degenerate elliptic systems
Authors: Martio Olli , Miklyukov Vladimir , Vuorinen Matti
Published: January 2005

The system

a

u
x

+
b

u
y

=

v
y

,

c

u
x

+
d

u
y

=
−

v
x

,

au_x+ bu_y=v_y,\quad cu_x+du_y=-v_x ,

which yields Beltrami’s system if

b
=
c

b=c

, is considered. Under a condition for the coefficients

a
,
b
,
c
,
d

a,b,c,d

a non-existence theorem is proved.
A counterexample to the existence of a local plurisubharmonic peak function at infinity
Authors: Park Sung-Hee
Published: January 2005

We give an example of an unbounded pseudoconvex Reinhardt domain in

C

n

,
 
n
≥
4

\mathbb {C}^n,\ n\ge 4

, which is Kobayashi complete but admits no local plurisubharmonic peak function at infinity.
Orbital integrals are motivic
Authors: Hales Thomas
Published: January 2005

This article shows that under general conditions,

p
p

-adic orbital integrals of definable functions are represented as the trace of a Frobenius operator on a virtual motive. This gives an explicit example of the philosophy of Denef and Loeser, which predicts that all “naturally occurring”

p
p

-adic integrals are motivic.
𝑆-invariant subspaces of 𝐿^{𝑝}(𝐓)
Authors: Redett D.
Published: January 2005

In this note, we give a new proof of the characterization of the

S
S

-invariant subspaces of

L
p

(

T

)

L^p(\mathbf {T})

for

p
p

in

P

≡
{
p
:
1
>
p
>
∞
,
p
≠
2
}

\mathcal {P}\equiv \{ p : 1 >p > \infty , p \neq 2 \}

using ideas from approximation theory.
Weakly compact operators into sequence spaces: A counterexample
Authors: Ylinen Kari
Published: January 2005

In a recent paper Gutiérrez and Villanueva have used, without giving a detailed proof, an analogue of a well-known result of Ryan characterizing the weakly compact operators from a Banach space

E
E

into the space

c
0

(
X
)

c_0(X)

of null sequences in a Banach space

X
X

. In this note a counterexample is given showing that in the statement of Gutiérrez and Villanueva an additional condition is needed.
A new degree bound for invariant rings
Authors: Chuai Jianjun
Published: January 2005

In this paper we give a new degree bound for polynomial invariant rings of finite groups and give some applications.
Some estimates of norms of random matrices
Authors: Latała Rafał
Published: January 2005

We show that for any random matrix

(

X

i
j

)

(X_{ij})

with independent mean zero entries
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="bold upper E double-vertical-bar left-parenthesis upper X Subscript i j Baseline right-parenthesis double-vertical-bar less-than-or-equal-to upper C left-parenthesis max Underscript i Endscripts StartRoot sigma-summation Underscript j Endscripts bold upper E upper X Subscript i j Superscript 2 Baseline EndRoot plus max Underscript j Endscripts StartRoot sigma-summation Underscript i Endscripts bold upper E upper X Subscript i j Superscript 2 Baseline EndRoot plus RootIndex 4 StartRoot sigma-summation Underscript i j Endscripts bold upper E upper X Subscript i j Superscript 4 Baseline EndRoot right-parenthesis comma">

E

‖
(

X

i
j

)
‖
≤
C

(

max

i

∑

j

E

X

i
j

2

+

max

j

∑

i

E

X

i
j

2

+

∑

i
j

E

X

i
j

4

4

)

,

\mathbf {E}\|(X_{ij})\|\leq C \Big (\max _{i}\sqrt {\sum _{j}\mathbf {E} X_{ij}^{2}}+ \max _{j}\sqrt {\sum _{i}\mathbf {E} X_{ij}^{2}}+ \sqrt [4]{\sum _{ij} \mathbf {E} X_{ij}^{4}} \Big ),

\]
where

C
C

is some universal constant.
Riesz points of upper triangular operator matrices
Authors: Barnes Bruce
Published: January 2005

Two results are proved which concern Riesz points of upper triangular operator matrices. Applications are made to questions involving when Weyl’s Theorem holds for an upper triangular operator matrix.
Moments of the probability density functions of error terms in divisor problems
Authors: Lau Yuk-Kam , Tsang Kai-Man
Published: January 2005

We derive an explicit formula for the moments of the probability density function of a class of functions. An application of this shows that the density function of the error term in the Pilz divisor problem is asymmetric.
Euler’s integrals and multiple sine functions
Authors: Koyama Shin-ya , Kurokawa Nobushige
Published: January 2005

We show that Euler’s famous integrals whose integrands contain the logarithm of the sine function are expressed via multiple sine functions.
Impact of Anesthesia Management Characteristics on Severe Morbidity and Mortality
Authors: Arbous M Sesmu , Meursing Anneke E. E. , van Kleef Jack W. , de Lange Jaap J. , Spoormans Huub H. A. J. M. , Touw Paul , Werner Frans M. , Grobbee Diederick E.
Published: January 2005

Background

Quantitative estimates of how anesthesia management impacts perioperative morbidity and mortality are limited. The authors performed a study to identify risk factors related to anesthesia management for 24-h postoperative severe morbidity and mortality.

Methods

A case-control study was performed of all patients undergoing anesthesia (1995-1997). Cases were patients who either remained comatose or died during or within 24 h of undergoing anesthesia. Controls were patients who neither remained comatose nor died during or within 24 hours of undergoing anesthesia. Data were collected by means of a questionnaire, the anesthesia and recovery form. Odds ratios were calculated for risk factors, adjusted for confounders.

Results

The cohort comprised 869,483 patients; 807 cases and 883 controls were analyzed. The incidence of 24-h postoperative death was 8.8 (95% confidence interval, 8.2-9.5) per 10,000 anesthetics. The incidence of coma was 0.5 (95% confidence interval, 0.3-0.6). Anesthesia management factors that were statistically significantly associated with a decreased risk were: equipment check with protocol and checklist (odds ratio, 0.64), documentation of the equipment check (odds ratio, 0.61), a directly available anesthesiologist (odds ratio, 0.46), no change of anesthesiologist during anesthesia (odds ratio, 0.44), presence of a full-time working anesthetic nurse (odds ratio, 0.41), two persons present at emergence (odds ratio, 0.69), reversal of anesthesia (for muscle relaxants and the combination of muscle relaxants and opiates; odds ratios, 0.10 and 0.29, respectively), and postoperative pain medication as opposed to no pain medication, particularly if administered epidurally or intramuscularly as opposed to intravenously.

Conclusions

Mortality after surgery is substantial and an association was established between perioperative coma and death and anesthesia management factors like intraoperative presence of anesthesia personnel, administration of drugs intraoperatively and postoperatively, and characteristics of delivered intraoperative and postoperative anesthetic care.
Effects of Epidural Saline Injection on Cerebrospinal Fluid Volume and Velocity Waveform
Authors: Higuchi Hideyuki , Adachi Yushi , Kazama Tomiei
Published: January 2005

Background

The phenomenon of epidural "top-up" (increased spread of local anesthetic due to epidural fluid injection) is explained partly by an epidural volume effect. This study was designed to investigate the change in cerebrospinal fluid (CSF) volume and velocity waveform induced by epidural saline injection.

Methods

(1) Lumbar epidural catheters were placed in 28 patients. Magnetic resonance images were obtained for measurements of lumbosacral CSF volume and velocity waveform. Saline was injected into the epidural space through the catheter to three groups of randomly assigned patients: 5-ml saline (n = 10), 10-ml saline (n = 9), and 15-ml saline (n = 9) groups. A repeat image series was performed after epidural injection to compare CSF volume and velocity waveform before and after epidural injection. (2) We also examined the time course of dural sac compression after epidural saline injection in a separate series. Seven axial images at disk levels from T11-T12 to L5-S1 were obtained before injection and 1, 3, 5, 10, 15, 20, 25, and 30 min after 10-ml saline injection to compare each dural area before and after injection.

Results

(1) Saline injected through the epidural catheter compressed the dural sac with variability of the extent of compression, resulting in a significantly decreased CSF volume in all patients (P <== 0.001). The mean reductions in CSF volume were 2.0 +/- 1.0 ml in the 5-ml group, 4.4 +/- 1.4 in the 10-ml group, and 7.2 +/- 2.6 in the 15-ml group. There were significant differences among the three groups (P < 0.05 approximately 0.001). After the saline injection, the synchronization between the CSF velocity waveform and the cardiac cycle disappeared in significantly more patients in the 10-ml group (7 of 9 patients) than in the other groups (P < 0.05). However, there was no significant relation between measures of CSF velocity waveform and dural area in any patient. (2) The maximum reduction of the sum of the total of seven disk areas occurred 5 min after epidural saline injection; thereafter, dural compression was gradually restored but did not return to the value before injection for 30 min.

Conclusions

These findings indicate that the reduction in CSF volume was injection-volume dependent, dural compression lasted at least 30 min after saline injection, and the changes of the CSF flow dynamics did not correlate with the degree of dural sac compression.
Effects of Intraoperative Blood Salvage on Leukocyte Recruitment to the Endothelium
Authors: Nohé Boris , Ries Reiner , Ploppa Annette , Zanke Christof , Eichner Martin , Unertl Klaus , Dieterich Hans-Jürgen
Published: January 2005

Background

The contamination of salvaged wound blood with activated leukocytes has been suspected to play a role in leukocyte-mediated tissue injury by increased adhesion to the endothelium. To verify this hypothesis, the authors performed a clinical study to examine the effects of blood salvage on leukocyte-endothelial interactions.

Methods

Expression of L-selectin, CD18, and CD11b and leukocyte adhesion to activated endothelium from human umbilical veins were measured in 25 patients undergoing major orthopedic surgery. Adhesion of fluorescently labeled leukocytes was examined in a flow chamber at shear rates of 50-1,600 s. Comparisons were made between samples from venous blood and from processed salvaged wound blood (SWB).

Results

At 30% hematocrit, SWB contained 2,162 +/- 147 leukocytes/microl. In comparison with venous blood, CD11b was up-regulated in SWB 1.3- to 3.6-fold on monocytes and neutrophils, whereas L-selectin and CD18 decreased on monocytes by 53% and 15%, respectively (P < 0.05). Despite up-regulation of CD11b, firm adhesion was significantly reduced by 74-76% in SWB. Rolling fractions and rolling velocities were significantly higher in SWB, and their relation to shear rate was markedly altered (P < 0.01). In addition, adherent leukocytes from SWB were significantly less resistant to increments of shear rate than leukocytes from venous blood (P < 0.01).

Conclusions

Despite up-regulated CD11b, integrin-mediated adhesion is markedly impaired in salvaged blood. Therefore, the effect of blood salvage cannot be predicted from cell surface expression but rather from functional assays. The former hypothesis, that leukocytes from SWB aggravate leukocyte-mediated tissue injury by increased adhesion, may not be as great a concern as previously suggested.
Hemodynamic Changes after Protamine Administration
Authors: Welsby Ian J. , Newman Mark F. , Phillips-Bute Barbara , Messier Robert H. , Kakkis Emil D. , Stafford-Smith Mark
Published: January 2005

Background

Protamine sulfate is standard therapy to reverse heparin anticoagulation. Hemodynamic responses to protamine are common, ranging from minor perturbations to cardiovascular collapse. Although severe fatal reactions occur, the relation of less extreme responses with postoperative mortality is unknown. Therefore, the authors tested the hypothesis that hemodynamic "protamine reactions" (systemic hypotension and pulmonary hypertension) are associated with mortality after cardiac surgery.

Methods

In a university hospital setting, the authors studied 6,921 coronary bypass patients using automated anesthesia record-keeping data and quality assurance databases. Degree/duration integrals of systemic hypotension (< 100 mmHg) and pulmonary hypertension (> 30 mmHg) for the 30-min after protamine administration were assessed for linear associations with mortality using multiple logistic regression models adjusting for risk factors.

Results

Overall mortality was 2%; greater hemodynamic responses were associated with increased mortality by odds ratios of 1.28 (systemic hypotension: 95% confidence interval, 1.14-1.43; P < 0.001) and 1.27 (pulmonary hypertension: 95% confidence interval, 1.06-1.48; P < 0.001) per 150-mmHg . min increment. Proximity of the response to protamine administration strengthened the relation, which persisted after exclusion of major hemodynamic disturbances. Tests for linearity confirmed an association even at the lowest range of values for both pressure effects.

Conclusions

Hemodynamic perturbations after protamine administration are independently related to in-hospital mortality after primary coronary artery bypass surgery; the relation is present even in the lowest observed range of values for both systemic hypotension and pulmonary hypertension. Although randomized trials are necessary to address causality, this evidence suggests that strategies that avoid or attenuate these reactions may improve patient care.
Mechanical Ventilation Affects Lung Function and Cytokine Production in an Experimental Model of Endotoxemia
Authors: Brégeon Fabienne , Delpierre Stéphane , Chetaille Bruno , Kajikawa Osamu , Martin Thomas R , Autillo-Touati Amapola , Jammes Yves , Pugin Jérôme
Published: January 2005

Background

Mechanical ventilation using tidal volumes around 10 ml/kg and zero positive end-expiratory pressure is still commonly used in anesthesia. This strategy has been shown to aggravate lung injury and inflammation in preinjured lungs but not in healthy lungs. In this study, the authors investigated whether this strategy would result in lung injury during transient endotoxemia in the lungs of healthy animals.

Methods

Volume-controlled ventilation with a tidal volume of 10 ml/kg and zero positive end-expiratory pressure was applied in two groups of anesthetized-paralyzed rabbits receiving either intravenous injection of 5 mug/kg Escherichia coli lipopolysaccharide (n = 10) or saline (n = 10) 2 h after the start of mechanical ventilation. The third group consisted of 10 spontaneously breathing anesthetized animals receiving lipopolysaccharide. Anesthesia was then continued for 4 h in the three groups while the ventilatory modes were maintained unchanged. Lung injury was studied using blood gases, respiratory physiologic variables, analysis of the bronchoalveolar lavage cell counts, and cytokine concentrations and lung pathologic examination.

Results

Significant histologic lung alterations, hypoxemia, and altered lung mechanics were observed in rabbits treated with mechanical ventilation and intravenous lipopolysaccharide but not in the mechanically ventilated animals injected with saline or in spontaneously breathing animals treated with lipopolysaccharide. Endotoxemic ventilated animals also had significantly more lung inflammation as assessed by the alveolar concentration of neutrophils, and the concentrations of the chemokines interleukin 8 and growth-related oncogen alpha.

Conclusions

These results showed that positive-pressure mechanical ventilation using a tidal volume of 10 ml/kg and zero positive end-expiratory pressure was harmful in the setting of endotoxemia, suggesting that the use of this ventilator strategy in the operating room may predispose to lung injury when endotoxemia occurs.
Continuous Monitoring of Cerebrospinal Fluid Oxygen Tension in Relation to Motor Evoked Potentials during Spinal Cord Ischemia in Pigs
Authors: Lips Jeroen , de Haan Peter , Bouma Gert Joan , Holman Rebecca , van Dongen Eric , Kalkman Cor J.
Published: January 2005

Background

Perioperative assessment of spinal cord oxygenation might guide measures to prevent neurologic deficits secondary to ischemic or traumatic damage of the spinal cord. Although cerebrospinal fluid (CSF) partial pressure of oxygen (Po2) measurement has been used to detect spinal cord ischemia (SCI), the diagnostic value and the temporal resolution of CSF Po2 measurement compared with functional assessment of the spinal cord is unknown. This study compared CSF Po2 with transcranial motor evoked potentials (tcMEPs) for detection of experimental SCI.

Methods

The aorta and segmental arteries were exposed in 10 sufentanil-ketamine-anesthetized pigs (weight, 40-50 kg). Myogenic tcMEPs were recorded from the upper and lower limbs, and continuous assessment of CSF Po2 was provided by two Clark-type microcatheters inserted in the lumbar and thoracic intrathecal space. Graded lumbar SCI was produced by sequential clamping of segmental arteries. The relation between CSF Po2 and tcMEP during graded SCI was determined using linear regression. Diagnostic characteristics of CSF Po2 values for clinical SCI were determined using different cutoff points of CSF Po2.

Results

Lumbar CSF Po2 (baseline, 44 [interquartile range, 38-54] mmHg) decreased below 50% in all animals and was linearly related to loss of tcMEP amplitude in all animals. The median lumbar CSF Po2 during reduction of tcMEP to less than 25% of baseline was 11 (4-29) mmHg, whereas thoracic CSF Po2 remained constant (40 [28-50] mmHg). During absence of the tcMEP signal, lumbar CSF Po2 was less than 20 mmHg in 80% of the animals. Optimal sensitivity and predictive values of CSF Po2 measurement for SCI were in the range of 40-60% of baseline.

Conclusions

The data indicate that intrathecal Po2 measurement is a sensitive monitoring technique to track real-time changes in local spinal cord oxygenation. Continuous monitoring of CSF Po2 might be applied for evaluation of patients who are at risk for direct or secondary SCI.
Long-term Exposure to Local but Not Inhalation Anesthetics Affects Neurite Regeneration and Synapse Formation between Identified Lymnaea Neurons
Authors: Onizuka Shin , Takasaki Mayumi , Syed Naweed I.
Published: January 2005

Background

General and local anesthetics are used in various combinations during surgical procedures to repair damaged tissues and organs, which in almost all instances involve nervous system functions. Because synaptic transmission recovers rapidly from various inhalation anesthetics, it is generally assumed that their effects on nerve regeneration and synapse formation that precede injury or surgery may not be as detrimental as that of their local counterparts. However, a direct comparison of most commonly used inhalation (sevoflurane, isoflurane) and local anesthetics (lidocaine, bupivacaine), vis-a-vis their effects on synapse transmission, neurite regeneration, and synapse formation has not yet been performed.

Methods

In this study, using cell culture, electrophysiologic and imaging techniques on unequivocally identified presynaptic and postsynaptic neurons from the mollusc Lymnaea, the authors provided a comparative account of the effects of both general and local anesthetics on synaptic transmission, nerve regeneration, and synapse formation between cultured neurons.

Results

The data show that clinically used concentrations of both inhalation and local anesthetics affect synaptic transmission in a concentration-dependent and reversal manner. The authors provided the first direct evidence that long-term overnight treatment of cultured neurons with sevoflurane and isoflurane does not affect neurite regeneration, whereas both lidocaine and bupivacaine suppress neurite outgrowth completely. The soma-soma synapse model was then used to compare the effects of both types of agents on synapse formation. The authors found that local but not inhalation anesthetics drastically reduced the incidence of synapse formation. The local anesthetic-induced prevention of synapse formation most likely involved the failure of presynaptic machinery, which otherwise developed normally in the presence of both sevoflurane and isoflurane.

Conclusion

This study thus provides the first comparative, albeit preclinical, account of the effects of both general and local anesthetics on synaptic transmission, nerve regeneration, and synapse formation and demonstrates that clinically used lidocaine and bupivacaine have drastic long-term effects on neurite regeneration and synapse formation as compared with sevoflurane and isoflurane.
Remifentanil Preconditioning Confers Cardioprotection via Cardiac κ- and δ-Opioid Receptors
Authors: Zhang Ye , Irwin Michael G. , Wong Tak Ming , Chen Mai , Cao Chun-Mei
Published: January 2005

Background

Remifentanil preconditioning (RPC) reduces the infarct size in anesthetized rat hearts, and this effect seems to be mediated by all three types of opioid receptors (ORs). Because there is evidence of only kappa- and delta- but not mu-ORs in the rat heart, the authors investigated whether RPC confers cardioprotection via cardiac kappa- and delta-OR as well as via extracardiac mu-OR agonist activity. The authors also investigated the involvement of signaling mechanisms, namely protein kinase C and mitochondrial adenosine triphosphate-sensitive potassium (KATP) channels.

Methods

The hearts of male Sprague-Dawley rats weighing 190-210 g were removed, mounted on a Langendorff apparatus, and perfused retrogradely at 100 cm H2O with Krebs-Ringer's solution. All hearts were subjected to 30 min of ischemia and 2 h of reperfusion. The study consisted of three series of experiments on the effect of ischemic preconditioning or RPC (10, 50, and 100 ng/ml remifentanil) after blockade of OR subtypes (delta-OR antagonist naltrindol, kappa-OR antagonist nor-binaltorphimine, and mu-OR antagonist CTOP). The involvement of protein kinase C or the KATP channel in the cardioprotection of RPC was also investigated using specific blockers in each group. RPC was produced by three cycles of 5-min perfusion of remifentanil in Krebs-Ringer's solution interspersed with a 5-min reperfusion with Krebs solution only. Infarct size, as a percentage of the area at risk, was determined by 2,3,5-triphenyltetrazolium staining.

Results

Infarct size as a percentage of the area at risk was significantly reduced after RPC from 51.9 +/- 5.0% (control, n = 8) to 36.2 +/- 10.0% (100 ng/ml RPC, n = 8, P < 0.01). This effect was stopped by pretreatment with naltrindol (52.3 +/- 5.2%) and nor-binaltorphimine (43.5 +/- 6.0%) but not CTOP (37.1 +/- 6.0%). Chelerythrine and GF109203X, both protein kinase C inhibitors, abolished the effects of RPC or ischemic preconditioning on infarct size as a percentage of area at risk. 5-Hydroxydecanoate (a selective mitochondrial KATP channel blocker) also abolished the cardioprotection of RPC and IPC, but HMR-1098 (a selective inhibitor of the sarcolemmal KATP channel) did not.

Conclusion

Cardiac delta- and kappa- but not mu-ORs mediate the cardioprotection produced by RPC. Both protein kinase C and the mitochondrial KATP channel were involved in this effect.
Action of Isoflurane on the Substantia Gelatinosa Neurons of the Adult Rat Spinal Cord
Authors: Wakai Ayako , Kohno Tatsuro , Yamakura Tomohiro , Okamoto Manabu , Ataka Toyofumi , Baba Hiroshi
Published: January 2005

Background

Although isoflurane, a volatile anesthetic, can block the motor response to noxious stimulation (immobility and analgesia) and suppress autonomic responsiveness, how it exerts these effects at the neuronal level in the spinal cord is not fully understood.

Methods

The effects of a clinically relevant concentration (1 rat minimum alveolar concentration [MAC]) of isoflurane on electrically evoked and spontaneous excitatory/inhibitory transmission and on the response to exogenous administration of the gamma-aminobutyric acid type A receptor agonist muscimol were examined in lamina II neurons of adult rat spinal cord slices using the whole cell patch clamp technique. The effect of isoflurane on the action potential-generating membrane property was also examined.

Results

Bath-applied isoflurane (1.5%, 1 rat MAC) diminished dorsal root-evoked polysynaptic but not monosynaptic excitatory postsynaptic currents. Glutamatergic miniature excitatory postsynaptic currents were also unaffected by isoflurane. In contrast, isoflurane prolonged the decay phase of evoked and miniature gamma-aminobutyric acid type A receptor-mediated inhibitory postsynaptic currents and increased the amplitude of the muscimol-induced current. Isoflurane had little effect on action potential discharge activity.

Conclusions

Isoflurane augments gamma-aminobutyric acid-mediated inhibitory transmission, leading to a decrease in the excitability of spinal dorsal horn neurons. This may be a possible mechanism for the antinociceptive effect of isoflurane in the spinal cord.
Continuous Infusion of Ropivacaine for Pain Relief after Iliac Crest Bone Grafting for Shoulder Surgery
Authors: Blumenthal Stephan , Dullenkopf Alexander , Rentsch Katharina , Borgeat Alain
Published: January 2005

Background

The aim of the study was to compare the efficacy of either ropivacaine or placebo through an iliac crest (IC) catheter after Bankart repair with IC bone grafting.

Methods

With approval of the local ethics committee and after written informed consent was obtained, 36 patients had an interscalene catheter placed preoperatively. Intraoperatively, the surgeon placed a catheter at the IC donor site. At the end of surgery, 30 ml ropivacaine, 0.5% (ropivacaine group), or 30 ml NaCl, 0.9% (placebo group), was administered. Ropivacaine, 0.2%, was started 6 h after the initial block through the interscalene catheter for 48 h (t48) in all patients. At t0, the patient received either 5 ml/h ropivacaine, 0.2% (ropivacaine group), or 5 ml/h NaCl, 0.9% (placebo group), for 48 h through the IC catheter. All patients received an intravenous morphine patient-controlled analgesia device. Pain scores at the shoulder and at the IC donor site were assessed at rest and during motion every 8 h for 48 h and after 3 months. Plasma concentrations of total and unbound ropivacaine, morphine consumption, and patient satisfaction were assessed.

Results

At the IC donor site, pain was significantly lower in the ropivacaine group compared with the placebo group at rest and during motion at any time. Total and unbound plasma concentrations of ropivacaine were below the toxic threshold in both groups. Morphine consumption was significantly lower in the ropivacaine group after 24 and 48 h. Patient satisfaction was significantly higher in the ropivacaine group. At 3 months, pain at the IC during motion was significantly lower in the ropivacaine group.

Conclusions

Continuous application of 0.2% ropivacaine through an IC catheter after Bankart repair with IC bone grafting is an effective method for pain relief for the first 48 h, with few adverse effects and high patient satisfaction. The benefit of this technique is still present after 3 months.
A Randomized Controlled Trial to Evaluate S-Caine Patch™ for Reducing Pain Associated with Vascular Access in Children
Authors: Sethna Navil F. , Verghese Susan T. , Hannallah Raafat S. , Solodiuk Jean C. , Zurakowski David , Berde Charles B.
Published: January 2005

Background

A randomized, double-blinded trial was performed to evaluate the efficacy and safety of the S-Caine Patch (ZARS, Inc., Salt Lake City, UT), a eutectic mixture of lidocaine and tetracaine, for pain relief during venipuncture in children.

Methods

With institutional review board approval, parental consent, and patient assent, 64 children who were scheduled for medically indicated vascular access at two centers were randomly assigned (2:1) to receive either an S-Caine Patch or a placebo patch for 20 min before venipuncture procedures. The primary outcome measure was the child's rating of pain during venipuncture using the Oucher pain scale. Additional measures of efficacy included the blinded investigator's and an independent observer's four-point categorical scores. Variables were compared between treatments using Mantel-Haenszel summary chi-square tests or Pearson chi-square tests.

Results

The S-Caine Patch produced significantly greater pain relief compared with placebo (median Oucher scores of 0 vs. 60; P < 0.001). Fifty-nine percent of the children in the S-Caine Patch group reported no pain compared with 20% of the children in the placebo patch group. The investigator estimated that 76% of the children in the S-Caine Patch group experienced no pain during venipuncture versus 20% in the placebo patch group (P = 0.001). Independent observer ratings also favored the S-Caine Patchtrade mark (P < 0.001). Mild skin erythema (< 38%) and edema (< 2%) occurred with similar frequencies between the groups.

Conclusion

This study demonstrated that a 20-min application of the S-Caine Patch is effective in lessening pain associated with venipuncture procedures. Adverse events after S-Caine Patch application were mild and transient.