bluuebunny/crossref_metadata_2025 huggingface dataset:
GEOMETRICAL ORIGIN OF A COSMOLOGICAL TERM
Authors: HAMMOND RICHARD T.
Published: March 2007

Nonmetricity derived from a scalar field is shown to exist as a cosmic field, without direct coupling to matter. It leads to a variable cosmological term, a term that dominates the expansion in the early universe but dies away at later times.
NULL INFINITY, H-SPACE AND EQUATIONS OF MOTION
Authors: KOZAMEH CARLOS , NEWMAN EZRA T. , SILVA-ORTIGOZA GILBERTO
Published: March 2007

We discuss the existence, arising by analogy to that in algebraically special space–times, of a unique asymptotically shear-free congruence in any asymptotically flat space–time. Associated with this, is a unique complex analytic curve in H-space. The surprising potential physical significance of this curve is discussed.
GOOD POTENTIALS FOR ALMOST ISOMORPHISM OF COUNTABLE STATE MARKOV SHIFTS
Authors: BOYLE MIKE , BUZZI JEROME , GÓMEZ RICARDO
Published: March 2007

Almost isomorphism is an equivalence relation on countable state Markov shifts which provides a strong version of Borel conjugacy; still, for mixing SPR shifts, entropy is a complete invariant of almost isomorphism [2]. In this paper, we establish a class of potentials on countable state Markov shifts whose thermodynamic formalism is respected by almost isomorphism.
LIMIT THEOREMS FOR COUPLED INTERVAL MAPS
Authors: BARDET JEAN-BAPTISTE , GOUËZEL SÉBASTIEN , KELLER GERHARD
Published: March 2007

We prove a local limit theorem for Lipschitz continuous observables on a weakly coupled lattice of piecewise expanding mixing interval maps. The core of the paper is a proof that the spectral radii of the Fourier-transfer operators for such a system are strictly less than 1. This extends the approach of [9] where the ordinary transfer operator was studied.
SYMBOLIC AND GEOMETRIC LOCAL DIMENSIONS OF SELF-AFFINE MULTIFRACTAL SIERPINSKI SPONGES IN ℝd
Authors: OLSEN L.
Published: March 2007

In this paper we study the multifractal structure of a certain class of self-affine measures known as self-affine multifractal Sierpinski sponges. Multifractal analysis studies the local scaling behaviour of measures. In particular, multifractal analysis studies the so-called local dimension and the multifractal spectrum of measures. The multifractal structure of self-similar measures satisfying the Open Set Condition is by now well understood. However, the multifractal structure of self-affine multifractal Sierpinski sponges is significantly less well understood. The local dimensions and the multifractal spectrum of self-affine multifractal Sierpinski sponges are only known provided a very restrictive separation condition, known as the Very Strong Separation Condition (VSSC), is satisfied. In this paper we investigate the multifractal structure of general self-affine multifractal Sierpinski sponges without assuming any additional conditions (and, in particular, without assuming the VSSC).
RECURRENCE FOR PERSISTENT RANDOM WALKS IN TWO DIMENSIONS
Authors: LENCI MARCO
Published: March 2007

We discuss the question of recurrence for persistent, or Newtonian, random walks in ℤ2, i.e. random walks whose transition probabilities depend both on the walker's position and incoming direction. We use results by Tóth and Schmidt–Conze to prove recurrence for a large class of such processes, including all "invertible" walks in elliptic random environments. Furthermore, rewriting our Newtonian walks as ordinary random walks in a suitable graph, we gain a better idea of the geometric features of the problem, and obtain further examples of recurrence.
ROBUST FILTERING AND DETECTION OF AN INSURANCE MODEL
Authors: AGGOUN LAKHDAR
Published: March 2007

Risk theory deals with stochastic models in insurance business. Usually, in such models claims are described by point processes and the amounts claimed by policy holders are sequences of random variables. The profit or loss, of the company is the difference between premiums income and the claims. We assume that we have a certain number of competing models, describing the claims and premiums rate processes. We are interested in ranking the candidate models based on their likelihood of being most appropriate for describing these processes. We compute robust dynamics for our estimates. In these new dynamics stochastic integration disappear and stochastic differential equations become ordinary differential equations.
LARGE DEVIATION ASYMPTOTICS FOR RANDOM-WALK TYPE PERTURBATIONS
Authors: YANG ZHIHUI
Published: March 2007

Symmetric random walks can be arranged to converge to a Wiener process in the area of normal deviation. However, random walks and Wiener processes have, in general, different asymptotics of the large deviation probabilities. The action functionals for random-walks and Wiener processes are compared in this paper. The correction term is calculated. Exit problem and stochastic resonance for random-walk-type perturbation are also considered and compared with the white-noise-type perturbation.
LIMIT LAWS FOR DISTORTED CRITICAL RETURN TIME PROCESSES IN INFINITE ERGODIC THEORY
Authors: KESSEBÖHMER MARC , SLASSI MEHDI
Published: March 2007

We consider conservative ergodic measure preserving transformations on infinite measure spaces and investigate the asymptotic behaviour of distorted return time processes with respect to sets satisfying a type of Darling–Kac condition. We identify two critical cases for which we prove uniform distribution laws.
AT1receptor blockade prevents interstitial and glomerular apoptosis but not fibrosis in pigs with neonatal induced partial unilateral ureteral obstruction
Authors: Eskild-Jensen Anni , Paulsen Lene Fogt , Wogensen Lise , Olesen Ping , Pedersen Lea , Frøkiær Jørgen , Nyengaard Jens Randel
Published: March 2007

Obstruction-induced fibrosis is a leading cause of end-stage renal failure in children. The pathophysiological mechanisms may involve apoptosis and the renin-angiotensin system. We studied apoptosis and fibrosis in a well-established neonatal pig model with unilateral partial ureteral obstruction (PUUO) induced during ongoing nephrogenesis in 2-day-old piglets. The role of angiotensin II (ANG II) was studied using the AT1receptor blocker CV-11974 (0.12 mg/h candesartan from age 23 to 30 days). At day 30 the kidneys were perfusion fixed and fibrosis, apoptosis, and tubular lengths were quantitated using stereological methods, picro Sirius red staining, and immunohistochemical techniques identifying activated caspase 3, aquaporin-2 (AQP2), and von Willebrand factor. The collagen content was assessed by hydroxyproline density. Neonatal induced PUUO increased interstitial and glomerular cell apoptosis and fibrosis. At this stage, PUUO did not increase tubular cell apoptosis or decrease tubular length and cell number. AT1receptor blockade prevented the PUUO-induced interstitial and glomerular cell apoptosis but did not attenuate fibrosis. In conclusion, AT1receptor blockade after the end of nephrogenesis may prevent interstitial and glomerular cell apoptosis but not fibrosis, suggesting that pathways not involving AT1receptor stimulation contribute to neonatal obstruction-induced fibrosis or that prevention of interstitial cell apoptosis counteracts a potential antifibrotic effect of AT1receptor blockade in this pig model of congenital obstructive nephropathy. Our results demonstrate that ANG II plays a role in PUUO-induced glomerular cell apoptosis.
Laser Cleaning and Spectroscopy: A Synergistic Approach in the Conservation of a Modern Painting
Authors: Melessanaki K. , Stringari C. , Fotakis C. , Anglos D.
Published: March 2007

We present results from preliminary laser cleaning studies performed on a 20th century modern painting, in which laser-induced breakdown spectroscopy (LIBS) was employed for monitoring the progress of material removal. This synergistic approach, that combines laser ablation cleaning with spectroscopic control, is of obvious importance as it offers a reliable means of ensuring proper conservation and could be the basis of a standard
protocol for laser-based restoration procedures.
Picosecond Absorption Spectra and Relaxation Processes of the Excited Singlet State of Pyrene in Solution
Authors: Miyasaka Hiroshi , Masuhara Hiroshi , Mataga Noboru
Published: March 2007

The method of analysis for the ps transient absorption spectra obtained by a
ps Nd3+: YAG laser photolysis system is described in detail, showing the results of
pyrene in solution. The Sn ← S1 spectrum observed immediately after excitation is rather broad and its intensity in the short wavelength region is relatively enhanced, compared to the spectrum observed at later stages. For elucidating this fast spectral change, the spectrum at 0 ps was simulated from that at 100 ps, evaluating numerically the inner filter effect, depletion of the ground state molecules and temporal characteristics of the monitoring ps continuum. The difference between the simulated and experimentally observed spectra may be ascribed to the nonlinear refractive index change of the solvent, the thermal lensing effect, or to an intrinsic relaxation of the excited molecule. Examining absorption spectra obtained under various conditions, the former two possibilities were denied for the excited pyrene system. Vibrational relaxation as well as the S2 → S1 internal conversion with a time constant of less than 10 ps have been suggested to be responsible for this difference between the simulated and observed spectra.
Preliminary Study on Kinetic Energy Distributions of Ar+ FragmentsResulting From Ar3+ Visible Photodissociation
Authors: Gadea F. X. , Durup J.
Published: March 2007

According to a strategy which involves DIM excitonic Hamiltonian, DIM‐like transition dipole moments,
realistic dynamical propagations with the HWD method (Hemiquantal dynamics with the Whole DIM
basis), and the Wigner function to weight the initial conditions, a non‐empirical theoretical study of the
kinetic energy distribution of the Ar+ photofragments is performed for three total energies. The results
illustrate the dominant symmetric stretching motion and the importance of non‐adiabatic effects in the
dissociation dynamics.
Picosecond Flash Photolysis of Photochromic Spiropyrans
Authors: Krysanov S. A. , Alfimov M. V.
Published: March 2007

The transient species involved in photocoloration and photobleaching of indoline
6‐nitrosubstituted spiropyran solutions at room temperature were studied by
picosecond flash photolysis. Transient absorption spectrum of spiropyran colorless
form consists of two bands peaked at 440 and 585 nm and is assigned to the photoinduced
intermediate non‐planar cis configuration with the breaked C—O bond of the
pyran ring. This transient is found to have the buildup time shorter than 10 ps and
initial decay times of about 10 ns in benzene and 5 ns in ethanol. The colored form
exhibits the transient absorption peaked at 460 nm with the lifetime of about 200 ps
in ethanol which is assigned to Sn ← S1 absorption of colored form. The predominant
decay channel of the colored form S1 state is shown to be internal conversion S1 ⇝ S0
with the quantum yield of about 0.70 ± 0.15.
Photochemistry in Van Der WaalsComplexes: (Hg—H2)* → HgH + H
Authors: Jouvet Christophe , Soep Benoit
Published: March 2007

The Hg—H2 collision complex in the reaction Hg 3P1 + H2 has been investigated by a
new method involving the Van der Waals complex of the reactants. This method yields
the first observation of a vibrational transition in a reactive collision complex. Furthermore
the fixed geometry of the Van der Waals complex corresponding to the Hg 3P1
state enables the separation of two different reaction paths depending on the electronic
configuration of the complex, namely  3Σ and  3Π.
Screened Anode N2 Laser
Authors: Sabry M. Montaser Foad
Published: March 2007

An experimental study of the effect of screening the discharge channel on the output
energy is presented. It has been found that a screened anode nitrogen laser generates
higher output energy than that of a screened cathode, and also higher than that when
both cathode and anode are unshielded at higher pressures.
Excimeric Emission andPhotochemical Behavior ofp‐Phenylenediacrylic Acid(p‐PDA) and its Diethyl‐Ester(p‐PDAEt)
Authors: Ebeid El-Zeiny M. , El-Daly Samy A. , Hasegawa Masaki
Published: March 2007

p‐Phenylenediacrylic acid (p‐PDA) displays excimeric emission in concentrated solutions (concentration ca. 0.5 M) in dimethylsulphoxide (DMSO). The excimeric
emission maximum is red shifted by ca. 5200 cm–1 compared with molecular emission
maximum. The fluorescence quantum yields of p‐PDA has been measured in DMSO
(φf = 0.09, λex = 337 nm) and in cetyltrimethylammonium chloride (CTAC) cationic
micelles that show remarkable solubilization of p‐PDA.

The solution photoreactivity of p‐PDA is wavelength dependent. In dilute DMSO
solutions, 365 nm and 310 nm light causes p‐PDA consumption giving a photoproduct
of maximum absorption at ca. 265 n,. A back photoreaction is induced by 254 nm light.
The photochemical quantum yields (φc) of the forward photochemical reaction have
been measured as a function of temperature and the activation energy was evaluated
as Ea = 9 kJ mol–1 suggesting a unimolecular photoisomerization process.

Emission from crystalline p‐PDA has also been reported. The emission maximum is
red shifted from molecular emission maximum by ca. 3250 cm–1.

The energy transfer in the system diethyl‐p‐phenylenediacrylate (p‐PDAEt)‐1,4‐bis(β‐pyridyl‐2‐vinyl)benzene(P2VB) has been studied. Triplet states formation mechanism
is proposed.
The Small Molecule Limit of Infrared Multiphoton Dissociation: Collisional Effects in D2CO
Authors: Berman Michael R. , Moore C. Bradley
Published: March 2007

The infrared multiphoton excitation of D2CO was studied by monitoring infrared fluorescence from stretching modes of D2CO following excitation in the bending modes. The dependence of the infrared multiphoton dissociation yield on laser wavelength, on laser power, and on reactant and foreign gas pressures was also studied. Severe bottlenecks to excitation through the first few steps are found. Vibration‐to‐vibration transfer of a bending quantum from one excited D2CO molecule to another is a crucial step.
Collision‐induced changes of rotational quantum number must also play an important role.
Infrared Multiphoton Dissociation of CF3CHClF: Primary Dissociation and Secondary Photolysis
Authors: Kato Shuji , Makide Yoshihiro , Tominaga Takeshi , Takeuchi Kazuo
Published: March 2007

The dissociation yield and branching ratio in CO2 laser‐induced infrared multiphoton dissociation
(IRMPD) of CF3CHClF were investigated by irradiation at 9R(20) 1078.6 cm−1 under
an unfocused irradiation geometry (0.75‐2.3 J/cm2) and a mildly focused one (1.2‐18 J/cm2). By using a Br2‐scavenging technique, it was revealed that the primary dissociation of CF3CHClF proceeded mainly via three‐centered HCl molecular elimination and C‐Cl bond rupture, with minor contributions of C‐C bond rupture and HF molecular elimination at higher fluences. The secondary photolysis of the primarily produced species during the laser pulse to yield CF2 and CClF carbenes depended strongly upon the laser fluence.
IR Photodecomposition of CH3COCF3
Authors: Fantoni R. , Borsella E. , Piccirillo S. , Giardini-Guidoni A. , Teghil R.
Published: March 2007

IR multiple‐photon decomposition of 1,1,1‐trifluoroacetone has been achieved in bulk by irradiating molecules with 970.55 cm−1 laser radiation. In collisional regime the onset of laser induced breakdown has been observed. Primary fragmentation and subsequent ion and radical secondary reactions have been monitored detecting the spontaneous luminescence with a gateable Optical Multichannel Analyzer.
Synthesis, Characterization and High In Vitro Antitumour Activityof Novel Triphenyltin Carboxylates
Authors: Gielen Marcel , El Khloufi Abdelaziz , Biesemans Monique , Bouhdid Abdeslam , de Vos Dick , Mahieu Bernard , Willem Rudolph
Published: March 2007

The synthesis and spectral characterization of six novel triphenyltin compounds are described. The
in vitro antitumour activity of three of these compounds against two human tumour cell lines, MCF‐7,
a mammary tumour, and WiDr, a colon carcinoma, was determined. All three compounds are more
active than cis‐platin, etoposide and doxorubicin against both tumour cell lines. They are as active
as mitomycin C against WiDr, but less active against MCF‐7.
Metallation of Isatin(2,3‐Indolinedione). X‐Ray Structure and Solution Behavior ofBis(Isatinato)Mercury(II)
Authors: Garcia-Raso Angel , Fiol Juan J. , Molins Elies , Calafat Antonia M. , Marzilli Patricia A. , Marzilli Luigi G.
Published: March 2007

The first X‐ray structure of an isatin (2,3‐indolinedione, isaH) metal complex,
bis(isatinato)memury(II) (C16H8N2O4Hg)
(1), was determined. (1) was obtained from the reaction of
isaH with mercury(II) acetate in methanol. Analogously, treatment of sodium saccharinate and
mercury(II) acetate in methanol yielded
(3). (1) crystallizes in the
monoclinic system, space group P21/a with a = 7.299(1) Å, b
= 8.192(1) Å, c
= 11.601(1) Å , β = 105.82(1)°, V = 667.4 Å3, Z = 2, Dcalc = 2.452 g cm−3, MoKα radiation(λ = 0.71073 Å), μ = 115.5 cm-1, F(000) = 460, 21(1) °C. The structure was refined on the basis of 2023 observed reflections
to R= 0.044. The two deprotonated, non coplanar isa ligands are trans to each other in a head to
tail orientation and bound to the Hg through the nitrogen in a linear N‐Hg‐N arrangement. The Hg
atom is at the center of symmetry of the complex and displaced by 0.62 Å from the two planes of the
isa ligands (τ Hg‐N1‐C2‐O2= ‐16°). The Hg‐N bond length is 2.015 Å. Noπ‐aryl‐memury(ll)‐π‐aryl stacking interaction was observed either in the solid state or in the solution state. The IR, electronic,
and  1H
and  13CNMR spectral data of (1) and (3) suggest binding of the memury to the heterocyclic
nitrogen, in agreement with the crystal structure determination of (1).
Cyclic Voltammetry of Auranofin
Authors: Mohamed Ahmed A. , Bruce Alice E. , Bruce Mitchell R. M.
Published: March 2007

The oxidative behavior of Auranofin, 2,3,4,6‐tetra‐O‐acetyl‐1‐thio‐β
‐D‐glucopyranosato‐
S(triethylphosphine)gold(I), was investigated by using cyclic voltammetry (CV) in 0.1 M
Bu4NPF6/CH2Cl2
and 0.1 M Bu4NPF4/CH2Cl2 solutions using Pt working and auxiliary electrodes
and a Ag/AgCI reference. CV studies at scan rates from 50‐2,000 mV/s and Auranofin
concentrations between 1 and 4 mM, show two irreversible oxidation processes occurring at
+1.1 V and +1.6 V vs. Ag/AgCl. Ph3PAu
(p‐thiocresolate) was also investigated as a reference for
comparison of the oxidation processes in Auranofin to that of other phosphine gold thiolate
complexes previously reported. The electrochemical response appears to be sensitive to
adsorption at the electrode as well as to the nature of the supporting electrolyte solution.
Repeated cycling shows a build up of products at the electrode.
Reactions of Organic Disulfides and Gold(I) Complexes
Authors: DiLorenzo Melanie , Ganesh Shantheni , Tadayon Lily , Chen Jinhua , Bruce Mitchell R. M. , Bruce Alice E.
Published: March 2007

Gold‐thiolate/disulfide exchange reactions of
with Ph3PAu(SC6H4CH3)
,
dppm, and dppe
were investigated. The rate of reactivity of the
gold‐thiolate complexes with
is: dppm
dppePh3PAu(SC6H4CH3). This order correlates with conductivity measurements and two ionic mechanisms
have been evaluated.  1H
NMR experiments demonstrate that in the reaction of dppm
with
, the mixed disulfide, ClC6H4SSC6H4CH3, forms first, followed by the formation of
. The rate law is first order in
and partial order in dppm. Results from electrochemical and chemical reactivity studies suggest that free thiolate is not involved in
the gold‐thiolate/disulfide exchange reaction. A more likely source of ions is the dissociation of a proton
from the methylene backbone of the dppm ligand which has been shown to exchange with D2O. The
implications of this are discussed in terms of a possible mechanism for the gold‐thiolate/disulfide
exchange reaction.
Biologically‐Active Gold(III) Complexes
Authors: Parish R. V.
Published: March 2007

A review is given of the background to and results of the succesful pharmacological testing of [AuX2(damp)] (X = Cl, OAc; damp = 2 − Me2NCH2C6H4) against a range of microbes, fungi and tumouts, culminating in in vivo xenografts of ZR‐1‐75. These are the first fully evaluated gold(III) complexes. The activity and reactions of the diacetato‐complex bear a resemblance to cisplatin, and some of the relevant chemistry is discussed. Preliminary screening data for C,P‐chelated tertiary phosphine derivatives of gold(III) are presented.
Dicyanogold Effects on Lymphokine Production
Authors: Tepperman Katherine , Roy Pamela W. , Moloney Brian F. , Elder R. C.
Published: March 2007

Having identified dicyanogold(I) as a common metabolite of gold‐based antiarthritis drugs, we are investigating the effects of the compound on the production of lymphokines. Handel, et al. 1
suggested that the transcription factor AP‐1, critical to the production of a number of cytokines, might be the target for gold compounds because of a critical cysteine within its DNA binding region. Using Jurkat cells, an established cell line as a model for CD4+
lymphocytes, we have shown that dicyanogold inhibits the binding of AP‐1 to DNA and inhibits the synthesis of IL‐2 mRNA and protein. In a macrophage line, THP‐1, which synthesizes IL‐1β
in response to mitogen, we have shown that dicyanogold inhibits the binding of a second transcription factor, CREB to DNA. Incubation of THP‐1 cells with dicyanogold inhibits the production of IL‐1β
mRNA. These results suggest that the mechanism of action of gold drugs may be through their interaction with transcription factors necessary for the immune activation seen in Rheumatoid Arthritis.
Role of glucocorticoids in neutrophil and endothelial adhesion molecule expression and function
Authors: Forsyth Kevin D. , Talbot Vivienne
Published: March 2007

Glucocorticoids are very effective inhibitors of both the acute and chronic inflammatory response. In this study the hypothesis that glucocorticoids inhibit an early component of the inflammatory response, neutrophil adhesion to endothelium, by down‐regulation of adhesion molecules on neutrophils or endothelium was examined. No effect of dexamethasone on neutrophil adhesion to endothelium or of antigen expression by neutrophils or endothelium was found. The mechanism of action of glucocorticoids in the inflammatory response is probably not mediated by alterations in adhesion molecules.
Human parathyroid hormone fragment stimulates the de novo synthesis of prostaglandin endoperoxide synthase in chick calvaria
Authors: Yang Chin-Yuh , Meng Ching-Liang , Wong Patrick Y- K.
Published: March 2007

The human parathyroid hormone N‐terminal fragment [hPTH‐(1–34)] increases the conversion of exogenous unsaturated fatty acids to prostaglandins (PGs) in calvarial homogenates. Enzyme activities were completely blocked by indomethacin (5 × 10−7 M), a PG synthase inhibitor, and actinomycin D (5 μM), an inhibitor of transcription, by binding to DNA. In addition, a potent inhibitor of protein synthesis, cycloheximide (10 μM), totally inhibited the stimulating effect of hPTH‐(1–34) on prostaglandin endoperoxide synthase (PG synthase, EC 1.14.99.1). The stimulatory effect of hPTH‐(1–34) on PG synthase was also reduced by the addition of stannous chloride. However, epidermal growth factor (EGF), platelet‐derived activating factor (PDGF), and ionophore A23187 did not show the same stimulating effect as hPTH‐(1–34) on PG synthase in calvaria. The results further demonstrated that PG synthase is a membrane‐bound enzyme in chick calvaria. In this communication, evidence is presented that hPTH‐(1–34) stimulates the de novo synthesis of PG synthase as demonstrated by the increased activity in calvarial homogenates and microsomes.
Dietary n‐3 Fatty Acids Inhibit Fever Induced by Inflammation in the Rat
Authors: Cooper A. L. , Turnbull A. V. , Hopkins S. J. , Rothwell N. J.
Published: March 2007

Modification of endogenous eicosanoid synthesis by dietary n‐3 fatty
acid supplementation reduces febrile responses, but the mechanisms
underlying these effects in vivo have not been determined. In the
present study, local inflammation was induced by intramuscular
injection ofturpentine in rats fed control or n‐3 supplemented diets
for 8‐9 weeks. In animals fed the control diet, turpentine induced
fever, hypermetabolism, marked local inflammation (oedema),
increased plasma IL‐6 concentrations and raised cerebrospinal fluid
(CSF) concentrations of PGE2. N‐3 fatty acid supplementation
significantly inhibited the rise in CSF PGE2, fever and
hypermetaboHsm induced by turpentine. Local inflammation and
increased plasma IL‐6 concentrations were not affected by n‐3
supplementation. These findings suggest that modification of dietary
fat intake inhibits fever via reduced release of prostaglandins,
probably within the brain, but does not affect the local or afferent
signals involved in fever generation.
Effect of Cromoglycate on Gas Changes, During Bronchial Challenge by UNCDW in Children with Asthma
Authors: Mappa L. , Bavaro S. , Moramarco G. , Torio D. , Falciatore D. , Ciccarone G. , Cicciomessere L. , Rigillo N.
Published: March 2007

Eighteen asthmatic children were challenged with ultrasonically
nebulized cold distilled water (UNCDW). Blood gas composition was
monitored transcutaneously (tcpO2 and tcpCO2)
during and after the challenge. Assuming as basal the response to
this UNCDW test, nine children (Group A) were then chosen at random
to inhale cromoglycate by aerosol delivery for 8 days. Nine children
(Group B), acting as a control, inhaled saline for 8 days. At the
end of this therapy, each child repeated the UNCDW test. Statistical
analysis with t‐test for paired data was used to compare the results
of each child to both tests. Mean basal tcpO2 and
tcpCO2 were all within the expected normal range. In all
children, both mean tcpO2 and tcpCO2 were
reduced during and after UNCDW inhalation. Mean tcpCO2
values during the challenge were significantly (p < 0.001) lower than the corresponding steady state 2 rain after the UNCDW
challenge, with a mean drop of −7% (2.1 S.D.). Mean
tcpO2 values remained significantly decreased
(p < 0.001) from the fifth mitt of the UNCDW challenge to the end of the
observation period, with a mean drop of −20% (15.5
S.D.). After treatment with cromoglycate (Group A), the mean
tcpCO2 values during UNCDW did not change significantly
from those ofsteady state conditions: −0.8% (0.5 S.D.);
whereas mean tcpO2 values decreased by −4%
(4.9 S.D.). The control children treated with saline (Group B)
showed mean tcpCO2 and tcpO2 values which were
significantly different (p < 0.001) from those of the steady
state conditions: mean drop of tcpCO2, −6%
(4.2 S.D.); mean drop of tcpO2, −20% (4.7
S.D.). In conclusion, it emerges that: UNCDW induces nonspecific
broncho‐constriction in asthmatic children with a typical drop of
tcpCO2 and tcpO2; the treatment with
cromoglycate normalizes the time course of tcpCO2
(hyper‐reactivity) and reduces dramatically the drop of
tcpO2 time course (hyper‐responsivity) during and after
the UNCDW test.
Effects of tumour necrosis factor‐α on BrdU incorporation in cultured human enterocytes
Authors: McDevitt J. , Feighery C. , O′Farrelly C. , Martin G. , Weir D. G. , Kelleher D.
Published: March 2007

Bromodeoxyuridine incorporation is a useful method for studying the pattern of DNA synthesis in proliferating cells. The distribution pattern of incorporated BrdU in villus enterocytes of duodenal explants was analysed after exposure to TNFα in organ culture. TNFα caused a consistent, low level uptake of BrdU in the portion of the nucleus close to the nuclear membrane, this pattern was absent from the control cultures. As these epithelial cells are terminally arrested in G0, the BrdU incorporation was thought not to be due to S phase DNA synthesis, but rather a response to the cytotoxic influence of TNFα. Microtitre plate proliferation assays of cell density and DNA synthesis were devised to study the effects of TNFα on confluent monolayers of the human foetal jejunal cell line I407 and the mouse fibrosarcoma cell line L929. Both cell lines showed a similar response to TNFα. Exposure to TNFα alone did not reduce cell numbers but did cause a significant increase in DNA synthesis (p < 0.05). When cycloheximtde was added in tandem with TNFα there was a significant reduction in cell number (p < 0.001) and level of DNA synthesis (p < 0.01) indicative of cell death. The DNA of cells exposed to TNFα and cycloheximide was fragmented when viewed on an electrophoresis gel. The results show that BrdU incorporation might be a good indicator of damage to the DNA of cells after cytotoxic insult. TNFα may be responsible for villus enterocyte damage in enteropathies such as coeliac disease and GVHR of the small bowel.
Platelet‐activating factor: an inflammatory mediator in the acute phase of allergic conjunctivitis in a guinea‐pig model
Authors: Meijer F. , Delft J. L. van , Haeringen N. J. van
Published: March 2007

The role of platelet‐activating factor (PAF) as a mediator of increased conjunctival vascular permeability was investigated in a guinea‐pig model of immediate hypersensitivity. Vascular permeability of the conjunctiva was determined by measuring the albumin content in lavage fluid (LF) after topical challenge with either PAF or ovalbumin. PAF produced a dose‐dependent increase of the vascular permeability within minutes. Topical pretreatment with levocabastine, a potent histamine H1‐antagonist demonstrated no effect towards the vascular permeability in response to PAF provocation. Pretreatment with eyedrops containing the specific PAF antagonist BN 52021 (1%) showed a significant inhibition of the vascular permeability (60.2%) and the clinical score (27.5%) after PAF challenge. In sensitized guinea‐pigs, levocabastine showed a marked inhibition of both the vascular permeability (80.5%) and the clinical score (70%) after topical challenge with ovalbumin. BN 2021, although to a lesser extent, showed a similar effect towards the vascular permeability (26.8%) and the clinical score (28%) after antigen provocation. When BN 52021 and levocabastine were administered in combination, the vascular permeability was significantly decreased after antigen challenge in comparison with eyes pretreated with levocabastine alone. These results indicate that PAF plays a role in the acute phase of allergic conjunctivitis in the guinea‐pig.
Th2 cells and cytokine networks in allergic inflammation of the lung
Authors: Coyle Anthony J. , Tsuyuki Shogo
Published: March 2007

The cytokines released from Th2 and Th2‐like cells are likely to be central to the pathophysiolgy of asthma and allergy, contributing to aberrant IgE production, eosinophilia and, perhaps, mucosal susceptibility to viral infection. IL‐4 has emerged as a central target, not only for B cell IgE production, but also in the commitment of both CD4+ and CD8+ T cells to cells with Th2 effector function capable of secreting IL‐5 resultlng in eosinophilic inflammation. In view of the central role of this cytokine and the evidence that glucocorticoids are unable to modify many IL‐4 dependent effects, Th2 inhibitors may prove to be novel therapies for the treatment of bronchial asthma.
Effect of dexamethasone on carrageenin‐induced inflammation in the lung
Authors: Smith S. F. , Benjamin A. , Dewar A. , Sheppard M. , Fox B. , Smith T. , Guz A. , Tetley T. D.
Published: March 2007

To study the anti‐inflammatory mechanisms of glucocorticoids, we have compared the effects of intratracheal carrageenin (2.5 mg) on control rats and those in which inflammation was subdued by prior dexamethasone treatment (10 mg/l in drinking water). Inflammation was maximal 48 h post‐carrageenin. After dexamethasone, carrageenin caused tittle inflammation or oedema (wet lung (mg), n = 6, mean ± S.E.M.; control, 995 ± 51; carrageenin + dexamethasone, 1144 ± 83; compared with carrageenin alone, 1881 ± 198), but rats had more lung lavage neutrophils than those given carrageenin alone (PMN × 106 /lung, mean ± S.E.M.; control, 0.055 ± 0.003; carrageenin + dexamethasone, 8.54 ± 1.52; compared with carrageenin alone, 6.30 ± 1.71). Proteolysis and partial inactivation of the anti‐inflammatory mediator, lipocortin 1 (Lcl), in carrageenin‐instilled rats was offset in those also given dexamethasone, by increased Lc1 levels (intact Lc1 ng/ml lavage fluid, n = 4, mean ± S.E.M.; control 24 ± 6; carrageenin 15 ± 4; carrageenin + dexamethasone, 40 ± 15). Maintenance of sufficient intact (fully active) extracellular Lc1 may contribute to the actions of glucocorticoids.
Myeloperoxidase and eosinophil cationic protein in serum and sputum during antibiotic treatment in cystic fibrosis patients with Pseudomonas aeruginosa infection
Authors: Niggemann B. , Stiller T. , Magdorf K. , Wahn U.
Published: March 2007

I order to study the time‐course of myeloperoxidase (MPO) and eosinophil cationic protein (ECP) as parameters for monitoring inflammation in cystic fibrosis (CF), we investigated ten patients during both a 14‐day intravenous antibiotic treatment and a corresponding self control. Modified Shwachman‐Kulczycki score improved significantly (p < 0.008), C‐reactive protein (CRP) levels decreased significantly (p < 0.05) during antibiotic treatment, while in the control phase there were no significant differences. Lung function parameters did not change significantly during antibiotic treatment or control phase. Serum MPO concentration (p < 0.006) and peripheral blood neutrophil granulocyte counts (p < 0.04) decreased significantly during antibiotic treatment, but not during the control phase. Sentm ECP concentration showed a tendency to decrease during antibiotic treatment, but this failed to reach significance. In general, sputum concentrations of MPO and ECP Were 500‐ to 1000‐fold higher than in serum. However, neither MPO nor ECP in sputum showed a significan variation over time during antibiotic treatment or control phase. From our data we conclude that: (1) measurements of MPO, neutrophils and CRP in peripheral blood do correlate with clinical parameters such as the modified Shwachman‐Kulczycki score; (2) neutrophils and MPO seem to reflect inflammatory changes induced by antibiotic treatment; (3) eosinophils may play a role in CF by an enhanced ‘releasability’ and (4) Sputum measurements of mediators of inflammation cannot be recommended.
Defective production of interferon‐γ and tumour necrosis factor‐α by AIDS mononuclear cells after in vitro exposure to Rhodococcus equi
Authors: Delia S. , Mastroianni C. M. , Lichtner M. , Mengoni F. , Moretti S. , Vullo V.
Published: March 2007

The production of interferon‐γ and tumour necrosis factor‐α was evaluated in the peripheral blood mononuclear cells (PBMCs) from healthy donors and AIDS patients after Rhodococcus equi infection in vitro. PBMCs from healthy donors secreted elevated levels of IFN‐γ and TNF‐α when challenged in vitro with killed R. equi, whereas the release of both cytokines was impaired in supernatant cultures from AIDS patients. We conclude that the failure of IFN‐γ generation in AIDS patients in response to R. equi is not antigen‐specific but it may reflect the global impairment of T‐cell function. In such patients, however, the infection with R. equi, a facultative intracellular pathogen which survives and replicates within macrophages, may be responsible for the impairment in the TNF‐α release, possibly enhancing the HIV‐induced macrophage dysftmction.
Circulating intercellular adhesion molecules in blood and bronchoalveolar lavage in Behçet′s disease
Authors: Hamzaoui A. , Hamzaoui K. , Chabbou A. , Ayed K.
Published: March 2007

The aim of this study was to evaluate circulating intercellular adhesion molecule‐1 (cICAM‐1) in serum and in bronchoalveolar lavage (BAL), as a marker for the inflammatory process in patients with active Behçet′s disease (BD). Circulating ICAM‐1 was tested by an enzyme linked immuno‐sorbent assay in serum and in BAL of patients with BD. These values were compared to those of patients with tuberculosis and to healthy controls. Increased levels of circulating ICAM‐1 were found in serum from patients with active BD compared to healthy controls (p < 0.01). Similar levels of serum cICAM‐1 were found in BD and tuberculosis. Additionally, both BD and tuberculosis patients exhibited high levels of cICAM‐1 in BAL fluid, suggesting that this increase may be a result of the immune system activation in inflammatory sites. Circulating ICAM‐1 seemed to have a good discriminative power in identifying active BD, being elevated in all active stages (p < 0.01) compared to remission BD stage. No differences were found in active BD patients depending upon the clinical manifestations. These results suggest that cICAM‐1 may be involved in leucocyte adhesion and migration into the vessel wall of the lung. Circulating forms are derived from molecules expressed on the surface of activated cells, as a result of an inflammatory process.
Participation of the adrenal gland in the anti‐inflammatory effect of polyunsaturated diets
Authors: Silveira V. L. F. , Limãos E. A. , Nunes D. W.
Published: March 2007

The effect of an n‐3 (fish) and n‐6 (soybean) fatty acid‐rich diet on carrageenin paw oedema in rats, and the participation of adrenal gland, corticosterone and α2‐macroglobulin (α2‐M) in this process were studied. A significant inhibition of carrageenin oedema was observed not only in rats fed a diet rich in fish oil but also in the soybean group. α2‐M was not detectable before carrageenin injection, suggesting that this putative antiinflammatory factor does not participate in the observed anti‐inflammatory effect. Corticosterone levels were higher in fat‐fed than in control rats, before carrageenin stimulus and adrenalectomy abolished the anti‐inflammatory response in fat‐fed animals, showing the important role of the adrenocortical hormones in this process.
IL‐6‐mediated MHC class II induction on RIN‐5AH insulinoma cells by IFN‐γ occurs via the G‐protein pathway
Authors: Vassiliadis S. , Papadopoulos G. K.
Published: March 2007

Major histocompatibility complex (MHC) class II antigen expression has been implicated in the pathogenesis of autoimmune type 1 diabetes. In this study we examined the role of various cytoldnes that may induce MHC class II surface antigen expression, using the rat insulinoma line RIN‐5AH as a pertinent model system. As in another study, the ability of IFN‐γ to amplify MHC class II antigen expression 4‐fold is demonstrated. At the same time we noted a 5‐fold increase of these histocompatibility antigens by IL‐6. Signal transduction analysis reveals that IL‐6‐induced MHC class II expression is specifically mediated by the G‐protein system (activation of p21ras by IL‐6) since mevalonic acid lactone (a Gprotein inhibitor) abolishes the action of IL‐6. In contrast, IFN‐γ, which does not activate p21ras, is not inhibited by protein kinase C (PKC) inhibitors but by those of the G‐protein pathway. This finding raises the possibility that IFN‐γ induces RIN cells to secrete IL‐6 (as shown previously, as well as in this paper) which, in turn, increases class II antigen expression via the G‐protein pathway. This action may be unique to IL‐6 or in synergy with IFN‐γ. Other cytokines such as IL‐1α and β, and TNF‐α induce a smaller increase in MHC class II antigens on RIN cells, and appear to activate both the G‐protein and the PKC signal transduction pathways to varying degrees. Therefore, injury of pancreatic β‐cells and possible induction of autoimmune type 1 diabetes via various cytokines may be caused by IL‐6 or IFN‐γ, or by their ability to induce MHC class II antigen upregulation.
Nasal hyperreactivity and inflammation in allergic rhinitis
Authors: Garrelds I. M. , Veld C. de Graaf-in′t , Wijk R. Gerth van , Zijlstra F. J.
Published: March 2007

The history of allergic disease goes back to 1819, when Bostock described his own ‘periodical affection of the eyes and chest’, which he called ‘summer catarrh’. Since they thought it was produced by the effluvium of new hay, this condition was also called hay fever. Later, in 1873, Blackley established that pollen played an important role in the causation of hay fever. Nowadays, the definition of allergy is ‘An untoward physiologic event mediated by a variety of different immunologic reactions’. In this review, the term allergy will be restricted to the IgE‐dependent reactions. The most important clinical manifestations of IgE‐dependent reactions are allergic conjunctivitis, allergic rhinitis, allergic asthma and atopic dermatitis. However, this review will be restricted to allergic rhinitis. The histopathological features of allergic inflammation involve an increase in blood flow and vascular permeability, leading to plasma exudation and the formation of oedema. In addition, a cascade of events occurs which involves a variety of inflammatory cells. These inflammatory cells migrate under the influence of chemotactic agents to the site of injury and induce the process of repair. Several types of inflammatory cells have been implicated in the pathogenesis of allergic rhinitis. After specific or nonspecific stimuli, inflammatory mediators are generated from cells normally found in the nose, such as mast cells, antigen‐presenting cells and epithelial cells (primary effector cells) and from cells recruited into the nose, such as basophils, eosinophils, lymphocytes, platelets and neutrophils (secondary effector cells). This review describes the identification of each of the inflammatory cells and their mediators which play a role in the perennial allergic processes in the nose of rhinitis patients.
Immune complex induced arthritis in rats: role of lipid mediators on cell infiltration
Authors: Rocha F. A. C. , Andrade L. E. C. , Jancar S.
Published: March 2007

We investigated the participation of lipid mediators in an experimental immune complex (IC) arthritis model in rats. The animals were subjected to intraarticular injection of anti‐bovine sertLm albumin (BSA) IgG antibodies followed by i.v. injection of BSA. Histopathological analysis of the synovial membranes disclosed infiltration of polymorphonuclear (PMN) cells and vascular congestion. Slight increase in vascular permeability, measured by Evans blue dye extravasation into the joints, was detected after 3 h of arthritis. Cellular influx into the articular cavities was most evident at the sixth hour of arthritis with predominance of PMN. Pretreatment with either indomethacin, a cyclooxygenase inhibitor, or L‐660,711, a peptido‐leukotriene antagonist, did not inhibit cell infiltration, whereas pretreatment with either L‐663,536, a 5‐lipoxygenase inhibitor, or L‐655,240, a thromboxane antagonist, significantly inhibited the phenomenon. Pretreatment with WEB 2170, a platelet activating factor (PAF) antagonist, also significantly inhibited cell influx. These results suggest that thromboxane, LTB4 and PAF mediate cell infiltration in this IC arthritis model.
Animal Models for Small for Gestational Age and Fetal Programing of Adult Disease
Authors: Vuguin Patricia M.
Published: March 2007

Fetal growth retardation is a fetal adaptation in response to inadequate supply of oxygen and/or nutrients. Animal models of intrauterine growth retardation are an invaluable tool to question the genetic, molecularand cellular events that determine fetal growth and development.Rodent and non-litter bearing animals are mammalian system with similar embryology,anatomy and physiology to humans. Utilization of these systems has led to a greater understanding of the pathophysiology and consequences of intrauterine growth retardation. These observations are comparable to that observed in humans born small for gestational age, and are of interest because of the known association between poor fetal growth and development of adult disease. Allthe experimental manipulations described here have altered a number of metabolic and physiological variables, but the pattern of alterations seems to vary with the procedure and species employed. This review describes animal models for intrauterine growth retardation and assesses their potentials and limitations at aiming to improve strategies for the prevention of adult disease.
Inducible Cre/loxP Recombination in the Mouse Proximal Tubule
Authors: Dworniczak Bernd , Skryabin Boris , Tchinda Joëlle , Heuck Silke , Seesing Franz-Josef , Metzger Daniel , Chambon Pierre , Horst Jürgen , Pennekamp Petra
Published: March 2007

Transgenic technologies in mice became invaluable experimental tools to identify the in vivo function of proteins. However, conventional knockout technology often results in embryonic lethality and because genes are frequently expressed in multiple cell types, the resulting knockout phenotypes can be complex and difficult or impossible to dissect. These issues are particularly important for gene-targeting strategies used to examine renal function. The kidney contains quite a number of different cell types, the function of many of which impacts that of other renal cells. To avoid these limitations conditional knockout strategies have been designed. As one important part of this system we describe the development of a mouse line expressing the tamoxifen-activatable Cre recombinase Cre-ERT2 specifically in renal proximal tubules. The expression of Cre-ERT2 is driven by a promoter fragment of the mouse γ-glutamyl transpeptidase type II gene resulting in the generation of the activatable recombinase in S3 segments of the proximal tubules from which over 80% were positive for Cre activity. In combination with loxP-based conditional mutant mice as a second tool this tamoxifen-inducible Cre-ERT2 line allows functional analysis of a variety of genes important for renal development and function in a precisely controlled spatiotemporal manner.
C-Reactive Protein-Induced Endothelial Microparticle Generation in HUVECs Is Related to BH4-Dependent NO Formation
Authors: Wang Jie-Mei , Wang Yan , Huang Jun-Yi , Yang Zhen , Chen Long , Wang Li-Chun , Tang An-Li , Lou Zhou-Fen , Tao Jun
Published: March 2007

Background: C-reactive protein (CRP) has been proven to facilitate endothelial injury via reduced NO production. Endothelial microparticles (EMPs) have emerged as a novel marker of endothelial injury. Methods: In vitro cultured human umbilical vein endothelial cells (HUVECs) were incubated with CRP (20 mg/l) for 24 h. The numbers of EMPs with CD31- and CD51-positive staining were assessed flow-cytometrically, and NO production was measured using the Griess reaction in the presence or absence of tetrahydrobiopterin (BH4), respectively. Results: The number of EMPs was significantly increased in HUVECs stimulated by CRP compared with the control group and, in parallel, NO production was decreased (p < 0.05). In the presence of CRP, pretreatment with BH4 decreased EMP counts and restored NO production to baseline levels (p < 0.05) while pretreatment with 2,4-diamino-6-hydroxypyrimidine (DAHP), a BH4 synthesis inhibitor, further prompted EMP formation and decreased NO production (p < 0.05). However, adding exogenous BH4 after pretreatment with DAHP suppressed EMP formation and restored NO production (p < 0.05). Conclusions: This study demonstrates that CRP induces EMP generation in HUVECs and this effect is, at least in part, related to impaired BH4-dependent NO production. Augmented EMP generation in HUVECs is suggested as a novel potential mechanism contributing to the pathogenesis of vascular injury related to CRP.