bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein kinase C (PKC) dependent induction of tissue factor (TF) by mesangial cells in response to inflammatory mediators and release during apoptosis
Authors: Lang Detlef , Terstesse Martin , Dohle Frank , Bangen Philip , Banas Bernhard , Pauels Hans‐Gerd , Heidenreich Stefan
Published: November 2002

In inflammatory kidney diseases procoagulatory activity (PCA) becomes evident. Glomerular fibrin deposits and capillary microthrombi are histopathological hallmarks in most forms of glomerulonephritis.

Therefore in this study the expression of tissue factor (TF) as the main inducer of thrombogenesis was examined in cultured human mesangial cells (MC) in response to proinflammatory stimuli such as interleukin‐1 (IL‐1β), tumour necrosis factor alpha (TNF‐α) and lipopolysaccharide (LPS). Also main signalling pathways were investigated.

IL‐1β, TNF‐α and LPS induced TF in MC in a time and dose dependent manner on mRNA and protein levels. Highest activity was found after 12 h of stimulation. Induction of TF was completely blockable by BAPTA‐AM, a chelator of intracellular [Ca2+]i as well as calphostin, a protein kinase C (PKC) inhibitor. Activation of the protein kinase A (PKA) pathway had no influence on basal TF expression, but down‐regulated cytokine‐induced TF. The PKA blocker, KT5720, increased TF formation significantly. Since TF exerts its activity primarily on the surface of cells and after release of encrypted receptors we further tested TF activity in MC supernatants. IL‐1β did not significantly increase TF activity in supernatants of intact cells. However, when MC were rendered apoptotic by oxidative metabolites, IL‐1β treated MC released highly stimulated TF activity into the supernatants, suggesting that a paracrine activation of the coagulatory cascade can take place under such conditions.

Inflammatory mediators up‐regulate TF expression in MC by a PKC dependent pathway whereas PKA can serve as a negative feed‐back link. Apoptosis of inflammatory MC may trigger to spread PCA.

British Journal of Pharmacology (2002) 137, 1116–1124. doi:10.1038/sj.bjp.0704967
Overexpression of glutathione S‐transferase A1‐1 in ECV 304 cells protects against busulfan mediated G2‐arrest and induces tissue factor expression
Authors: Ritter Christoph A , Sperker Bernhard , Grube Markus , Dressel Dana , Kunert‐Keil Christiane , Kroemer Heyo K
Published: November 2002

The antineoplastic drug busulfan is frequently used in preconditioning regimens for bone marrow transplantation. Pharmacokinetics vary tremendously between patients due to extensive metabolism in the liver via conjugation to glutathione catalysed by glutathione S‐transferase (GST) A1‐1. Since elevated busulfan plasma levels have been reported to be a risk factor for developing veno‐occlusive disease (VOD), metabolism of busulfan may play a pivotal role in the induction of VOD.

Therefore, we developed a cell model to investigate the influence of busulfan metabolism on its biological effects. GSTA1‐1 cDNA was transfected into the cell line ECV 304 and protein expression was demonstrated by Western blotting. Enzymatic activity could be detected by formation of tetrahydrothiophene. Additionally, effects of busulfan treatment on cell cycle and expression of tissue factor have been investigated.

A busulfan‐induced G2‐arrest was reduced in GSTA1‐1‐transfected cells, which consequently displayed a significantly higher activity of cdc2 kinase (24.1±1.5 AU mg−1 protein) after busulfan treatment compared to controls (14.7±2.3 AU mg−1 protein; P<0.01). Elevated basal expression of tissue factor in GSTA1‐1‐transfected ECV 304 cells could be 4 fold increased by busulfan treatment.

These data demonstrate that ECV 304 cells transfected with GSTA1‐1 provide a valuable tool to assess busulfan metabolism in vitro. Furthermore, overexpression of GSTA1‐1 leads to a partial protection against cell cycle effects of busulfan and affects tissue factor expression.

British Journal of Pharmacology (2002) 137, 1100–1106. doi:10.1038/sj.bjp.0704972
The isolated blood‐perfused rat heart: an inappropriate model for the study of ischaemia‐ and infarction‐related ventricular fibrillation
Authors: Clements‐Jewery Hugh , Hearse David J , Curtis Michael J
Published: November 2002

Well‐characterized in vivo and in vitro models exist for the study of ischaemia‐ and infarction‐related ventricular fibrillation (VF). In rats in vivo, VF appears to occur in distinct acute ischaemia‐ (early) and infarction‐related (late) phases. Interestingly, isolated buffer‐perfused rat hearts do not develop late VF. This raises the possibility that unidentified components of the blood may be responsible for late VF. We thus sought to characterize an isolated blood‐perfused rat heart in order to investigate the possible influence of blood components on arrhythmias arising from ischaemia and infarction.

Hearts, excised from male Wistar rats, were perfused in the Langendorff mode with blood from support rats (male Wistar, 350–430 g) via an extracorporeal circuit. Perfused hearts underwent left coronary artery occlusion for 240 min or a sham procedure (n=10 group−1).

Only 10% of ischaemic hearts developed late VF (90–240 min). Tissue myeloperoxidase activity (an index of neutrophil accumulation) increased during ischaemia from 0.017±0.004 (six fresh hearts) to 0.056±0.005 units mg protein−1 (P<0.05) at 240 min, but values were similar in sham hearts (0.083±0.013). Likewise, the decline (−1 vs 240 min of ischaemia shown) in circulating total white blood cells from 6.8±0.5 to 1.9±0.2×103 μl−1 and in platelets from 441±32 to 274±16×103 μl−1 (both P<0.05) was similar in time‐matched sham hearts (data not shown).

Surprisingly, only 10% of ischaemic hearts developed early VF (0–90 min), although the incidence of early ventricular tachycardia was 100% in these hearts (P<0.05 vs sham hearts). Blood K+ values were normal (hyperkalaemia suppresses VF).

Although late VF was absent in blood‐perfused hearts, it would be premature to conclude from this that late VF is not mediated by blood components. This is because the similar neutrophil accumulation in ischaemic and sham hearts, the decline in numbers of circulating blood components, and the unexpected paucity of early VF all question the validity of the model.

British Journal of Pharmacology (2002) 137, 1089–1099. doi:10.1038/sj.bjp.0704977
Altered kinetics and benzodiazepine sensitivity of a GABA
A
receptor subunit mutation [γ
2
(R43Q)] found in human epilepsy
Authors: Bowser David N. , Wagner David A. , Czajkowski Cynthia , Cromer Brett A. , Parker Michael W. , Wallace Robyn H. , Harkin Louise A. , Mulley John C. , Marini Carla , Berkovic Samuel F. , Williams David A. , Jones Mathew V. , Petrou Steven
Published: November 2002

The γ-aminobutyric acid type A (GABA
A
) receptor mediates fast inhibitory synaptic transmission in the CNS. Dysfunction of the GABA
A
receptor would be expected to cause neuronal hyperexcitability, a phenomenon linked with epileptogenesis. We have investigated the functional consequences of an arginine-to-glutamine mutation at position 43 within the GABA
A
γ
2
-subunit found in a family with childhood absence epilepsy and febrile seizures. Rapid-application experiments performed on receptors expressed in HEK-293 cells demonstrated that the mutation slows GABA
A
receptor deactivation and increases the rate of desensitization, resulting in an accumulation of desensitized receptors during repeated, short applications. In
Xenopus laevis
oocytes, two-electrode voltage-clamp analysis of steady-state currents obtained from α
1
β
2
γ
2
or α
1
β
2
γ
2
(R43Q) receptors did not reveal any differences in GABA sensitivity. However, differences in the benzodiazepine pharmacology of mutant receptors were apparent. Mutant receptors expressed in oocytes displayed reduced sensitivity to diazepam and flunitrazepam but not the imidazopyridine zolpidem. These results provide evidence of impaired GABA
A
receptor function that could decrease the efficacy of transmission at inhibitory synapses, possibly generating a hyperexcitable neuronal state in thalamocortical networks of epileptic patients possessing the mutant subunit.
Spectral mixing of rhythmic neuronal signals in sensory cortex
Authors: Ahrens Kurt F. , Levine Herbert , Suhl Harry , Kleinfeld David
Published: November 2002

The ability to compute the difference between two frequencies depends on a nonlinear operation that mixes two periodic signals. Behavioral and psychophysical evidence suggest that such mixing is likely to occur in the mammalian nervous system as a means to compare two rhythmic sensory signals, such as occurs in human audition, and as a means to lock an intrinsic rhythm to a sensory input. However, a neurological substrate for mixing has not been identified. Here we address the issue of nonlinear mixing of neuronal activity in the vibrissa primary sensory cortex of rat, a region that receives intrinsic as well as sensory-driven rhythmic input during natural whisking. In our preparation, the intrinsic signal originates from cortical oscillations that were induced by anesthetics, and the extrinsic input is introduced by periodic stimulation of vibrissae. We observed that the local extracellular current in vibrissa primary sensory cortex contained oscillatory components at the sum and difference of the intrinsic and extrinsic frequencies. In complementary experiments, we observed that the simultaneous stimulation of contralateral and ipsilateral vibrissae at different frequencies also led to current flow at the sum and difference frequencies. We show theoretically that the relative amplitudes of the observed mixture terms can be accounted for by a threshold nonlinearity in the input–output relation of the underlying neurons. In general, our results provide a neurological substrate for the modulation and demodulation of rhythmic neuronal signals for sensory coding and feedback stabilization of motor output.
Confirmation by FRET in individual living cells of the absence of significant amyloid β-mediated caspase 8 activation
Authors: Onuki Reiko , Nagasaki Akira , Kawasaki Hiroaki , Baba Tadashi , Uyeda Taro Q. P. , Taira Kazunari
Published: November 2002

When cells are exposed to death-inducing molecules such as tumor necrosis factor-α or Fas, caspase 8 is activated and cleaves an apoptotic facilitator, Bid, that is a member of the Bcl-2 family. After additional modification, the C-terminal moiety of Bid is translocated to the mitochondria and induces the release of cytochrome
c
into the cytoplasm. In an attempt to directly observe the cleavage of Bid and the following events in living cells, we constructed a vector that encoded Bid fused with yellow fluorescent protein (YFP) and cyan fluorescent protein (CFP) (YFP-Bid-CFP). On expression of YFP-Bid-CFP in mammalian cells, we were able to observe the efficient transfer of energy from excited CFP to YFP within the YFP-Bid-CFP molecule and, importantly, the fusion protein YFP-Bid-CFP was fully functional in cells. When YFP-Bid-CFP was cleaved by caspase 8, on activation by anti-Fas Abs but not by Aβ or tunicamycin, no such transfer of energy was detected. To our knowledge, this is the first report of (
i
) visualization of the activation of Bid by proteolytic cleavage, with direct observation of the cleavage of YFP-Bid-CFP in the cytoplasm and subsequent translocation of the cleaved Bid to mitochondria and (
ii
) the absence of Aβ- or tunicamycin-mediated significant activation of caspase 8 in individual living cells.
Cotranslational Partitioning of Nascent Prion Protein into Multiple Populations at the Translocation Channel
Authors: Kim Soo Jung , Hegde Ramanujan S.
Published: November 2002

The decisive events that direct a single polypeptide such as the prion protein (PrP) to be synthesized at the endoplasmic reticulum in both fully translocated and transmembrane forms are poorly understood. In this study, we demonstrate that the topological heterogeneity of PrP is determined cotranslationally, while at the translocation channel. By evaluating sequential intermediates during PrP topogenesis, we find that signal sequence-mediated initiation of translocation results in an interaction between nascent PrP and endoplasmic reticulum chaperones, committing the N terminus to the lumen. Synthesis of the transmembrane domain before completion of this step allows it to direct the generation ofCtmPrP, a transmembrane form with its N terminus in the cytosol. Thus, segregation of nascent PrP into different topological configurations is critically dependent on the precise timing of signal-mediated initiation of N-terminus translocation. Consequently, this step could be experimentally tuned to modify PrP topogenesis, including complete reversal of the elevatedCtmPrP caused by disease-associated mutations in the transmembrane domain. These results delineate the sequence of events involved in PrP biogenesis, explain the mechanism of action ofCtmPrP-favoring mutations associated with neurodegenerative disease, and more generally, reveal that translocation substrates can be cotranslationally partitioned into multiple populations at the translocon.
Motility Determinants in WASP Family Proteins
Authors: Yarar Defne , D'Alessio Joseph A. , Jeng Robert L. , Welch Matthew D.
Published: November 2002

In response to upstream signals, proteins in the Wiskott-Aldrich Syndrome protein (WASP) family regulate actin nucleation via the Arp2/3 complex. Despite intensive study of the function of WASP family proteins in nucleation, it is not yet understood how their distinct structural organization contributes to actin-based motility. Herein, we analyzed the activities of WASP and Scar1 truncation derivatives by using a bead-based motility assay. The minimal region of WASP sufficient to direct movement was the C-terminal WCA fragment, whereas the corresponding region of Scar1 was insufficient. In addition, the proline-rich regions of WASP and Scar1 and the Ena/VASP homology 1 (EVH1) domain of WASP independently enhanced motility rates. The contributions of these regions to motility could not be accounted for by their direct effects on actin nucleation with the Arp2/3 complex, suggesting that they stimulate motility by recruiting additional factors. We have identified profilin as one such factor. WASP- and Scar1-coated bead motility rates were significantly reduced by depletion of profilin and VASP and could be more efficiently rescued by a combination of VASP and wild-type profilin than by VASP and a mutant profilin that cannot bind proline-rich sequences. Moreover, motility of WASP WCA beads was not affected by the depletion or addback of VASP and profilin. Our results suggest that recruitment of factors, including profilin, by the proline-rich regions of WASP and Scar1 and the EVH1 domain of WASP stimulates cellular actin-based motility.
NONEQUILIBRIUM NONDISSIPATIVE THERMODYNAMICS — A NEW FIELD OF MODERN THERMODYNAMICS
Authors: WANG J.-T.
Published: November 2002

After 12 years of research on the thermodynamics of low-pressure diamond synthesis, a "bug" has been found hidden in classical thermodynamics for 150 years. On removing this bug, a new field of nonequilibrium nondissipative thermodynamics emerges, and the complete systematization of modern thermodynamics can be naturally obtained. It means that thermodynamics enters entirely into a new era: modern thermodynamics.
Chromosome Rearrangements and Transposable Elements
Authors: Lönnig Wolf-Ekkehard , Saedler Heinz
Published: November 2002

▪ Abstract  There has been limited corroboration to date for McClintock's vision of gene regulation by transposable elements (TEs), although her proposition on the origin of species by TE-induced complex chromosome reorganizations in combination with gene mutations, i.e., the involvement of both factors in relatively sudden formations of species in many plant and animal genera, has been more promising. Moreover, resolution is in sight for several seemingly contradictory phenomena such as the endless reshuffling of chromosome structures and gene sequences versus synteny and the constancy of living fossils (or stasis in general). Recent wide-ranging investigations have confirmed and enlarged the number of earlier cases of TE target site selection (hot spots for TE integration), implying preestablished rather than accidental chromosome rearrangements for nonhomologous recombination of host DNA. The possibility of a partly predetermined generation of biodiversity and new species is discussed. The views of several leading transposon experts on the rather abrupt origin of new species have not been synthesized into the macroevolutionary theory of the punctuated equilibrium school of paleontology inferred from thoroughly consistent features of the fossil record.
Association of ankylosing spondylitis with HLA–B*1403 in a West African population
Authors: López‐Larrea Carlos , Mijiyawa Moustafa , González Segundo , Fernández‐Morera J. Luis , Blanco‐Gelaz Miguel A. , Martínez‐Borra Jesús , López‐Vázquez Antonio
Published: November 2002

Objective

To investigate the contribution of HLA class I alleles in the susceptibility to primary ankylosing spondylitis (AS) in West African patients living in Togo.

Methods

A large epidemiologic analysis of 9,065 West African rheumatology patients living in Togo was performed in order to identify those who had AS. Eight Togolese patients with AS were identified. HLA was typed by polymerase chain reaction using sequence‐specific oligonucleotide probes. DNA typing was also performed on a control population of 85 healthy subjects matched for ethnic background.

Results

A significant association between AS and B*14 was identified. This allele was found in 62.5% of the AS patients (odds ratio 69), but was carried by only 2% of the healthy controls. Analysis for B14 subtypes showed that B*1403 was the predominant allele in AS patients (odds ratio 171), and that this allele was absent in healthy controls. B27 was virtually absent, being observed in only 1 AS patient (B*2705).

Conclusion

HLA–B*1403 shows the B27 “supertype” motif and may exert an effect on AS susceptibility according to the arthritogenic peptide model. The association of B*1403 with AS has not previously been reported in either population.
Stratification of pedigrees multiplex for systemic lupus erythematosus and for self‐reported rheumatoid arthritis detects a systemic lupus erythematosus susceptibility gene (SLER1) at 5p15.3
Authors: Namjou Bahram , Nath Swapan K. , Kilpatrick Jeff , Kelly Jennifer A. , Reid Jeff , James Judith A. , Harley John B.
Published: November 2002

Objective

Arthritis is a common manifestation in systemic lupus erythematosus (SLE), appearing in ∼85% of patients. Often, the polyarthritis at presentation of SLE cannot be distinguished from rheumatoid arthritis (RA) by physical examination or history. Indeed, physicians initially tell many SLE patients that they have RA (one source of “self‐reported RA”), only to have SLE established later. In addition, RA aggregates in families with an SLE proband. We predicted that pedigrees multiplex for both SLE and for self‐reported RA would better isolate particular genetic effects. If this proved to be true, we would then use the increased genetic homogeneity to more easily reveal genetic linkage.

Methods

From a collection of 160 pedigrees multiplex for SLE, we selected 36 pedigrees that also contained ≥2 members with self‐reported RA (19 pedigrees were African American, 14 were European American, and 3 were of other ethnic origin). Data from a genome scan of 307 microsatellite markers were evaluated for SLE linkage by contemporary genetic epidemiologic techniques.

Results

The most significant evidence of linkage to SLE was obtained at 5p15.3 in the European American pedigrees by both parametric (logarithm of odds [LOD] score 6.2, P = 9.3 × 10−8) and nonparametric (LOD score 6.9, P = 1.7 × 10−8) methods. The best‐fitting model for this putative SLE gene in this region was a recessive gene with a population frequency of 5% and with 50% penetrance in females and 15% penetrance in males at virtually 100% homogeneity.

Conclusion

For a genetically complex disease phenotype, an unusually powerful linkage has been found with SLE at 5p15.3 in European American pedigrees multiplex for SLE and for self‐reported RA. This result predicts the presence of a gene at the top of chromosome 5 in this subset of patients that is important for the pathogenesis of SLE.
Applying business management models in health care
Authors: Trisolini Michael G.
Published: November 2002

Most health care management training programmes and textbooks focus on only one or two models or conceptual frameworks, but the increasing complexity of health care organizations and their environments worldwide means that a broader perspective is needed. This paper reviews five management models developed for business organizations and analyses issues related to their application in health care.

Three older, more ‘traditional’ models are first presented. These include the functional areas model, the tasks model and the roles model. Each is shown to provide a valuable perspective, but to have limitations if used in isolation.

Two newer, more ‘innovative’ models are next discussed. These include total quality management (TQM) and reengineering. They have shown potential for enabling dramatic improvements in quality and cost, but have also been found to be more difficult to implement. A series of ‘lessons learned’ are presented to illustrate key success factors for applying them in health care organizations.

In sum, each of the five models is shown to provide a useful perspective for health care management. Health care managers should gain experience and training with a broader set of business management models. Copyright © 2002 John Wiley & Sons, Ltd.
An ab initio study of solvent polarity and hydrogen bonding effects on the nitrogen NMR shieldings of N,N‐dimethylacetamidine
Authors: Manalo Marlon N. , de Dios Angel C.
Published: November 2002

Density functional theory combined with the polarizable continuum model (PCM) and continuous set of gauge transformations method is applied to investigate the effects of solvent polarity on the nitrogen NMR shieldings of N, N‐dimethylacetamidine. Hydrogen bonding effects on shielding are likewise calculated using a supermolecule approach, where the imino group of the solute is hydrogen bonded with solvent. Theoretical results are compared with published experimental data. The PCM shielding calculations utilizing PCM‐optimized solute geometries yield results comparable to those obtained with the supermolecule approach. Geometry optimization of the solute appears to be more important in PCM shielding calculations than in the supermolecule approach. The large solvent shifts observed in water can only be reproduced when the N·H distance used in the calculation indicates full proton transfer from water to the imino nitrogen of the solute. Copyright © 2002 John Wiley & Sons, Ltd.
Diffusion NMR methods applied to xenon gas for materials study
Authors: Mair R. W. , Rosen M. S. , Wang R. , Cory D. G. , Walsworth R. L.
Published: November 2002

We report initial NMR studies of (i) xenon gas diffusion in model heterogeneous porous media and (ii) continuous flow laser‐polarized xenon gas. Both areas utilize the pulsed gradient spin‐echo (PGSE) techniques in the gas phase, with the aim of obtaining more sophisticated information than just translational self‐diffusion coefficients—a brief overview of this area is provided in the Introduction. The heterogeneous or multiple‐length scale model porous media consisted of random packs of mixed glass beads of two different sizes. We focus on observing the approach of the time‐dependent gas diffusion coefficient,D(t) (an indicator of mean squared displacement), to the long‐time asymptote, with the aim of understanding the long‐length scale structural information that may be derived from a heterogeneous porous system. We find thatD(t) of imbibed xenon gas at short diffusion times is similar for the mixed bead pack and a pack of the smaller sized beads alone, hence reflecting the pore surface area to volume ratio of the smaller bead sample. The approach ofD(t) to the long‐time limit follows that of a pack of the larger sized beads alone, although the limitingD(t) for the mixed bead pack is lower, reflecting the lower porosity of the sample compared to that of a pack of mono‐sized glass beads. The Padé approximation is used to interpolateD(t) data between the short‐ and long‐time limits. Initial studies of continuous flow laser‐polarized xenon gas demonstrate velocity‐sensitive imaging of much higher flows than can generally be obtained with liquids (20–200 mm s−1). Gas velocity imaging is, however, found to be limited to a resolution of about 1 mm s−1owing to the high diffusivity of gases compared with liquids. We also present the first gas‐phase NMR scattering, or diffusive‐diffraction, data, namely flow‐enhanced structural features in the echo attenuation data from laser‐polarized xenon flowing through a 2 mm glass bead pack. Copyright © 2002 John Wiley & Sons, Ltd.
On transonic viscous–inviscid interaction
Authors: BULDAKOV E. V. , RUBAN A. I.
Published: November 2002

The paper is concerned with the interaction between the boundary layer on a smooth
body surface and the outer inviscid compressible flow in the vicinity of a sonic
point. First, a family of local self-similar solutions of the Kármán–Guderley equation
describing the inviscid flow behaviour immediately outside the interaction region is
analysed; one of them was found to be suitable for describing the boundary-layer
separation. In this solution the pressure has a singularity at the sonic point with the
pressure gradient on the body surface being inversely proportional to the cubic root
dpw/dx ∼ (−x)−1/3 of the distance (−x) from the sonic point. This pressure gradient causes the boundary layer to interact with
the inviscid part of the flow. It is interesting
that the skin friction in the boundary layer upstream of the interaction region shows
a characteristic logarithmic decay which determines an unusual behaviour of the flow
inside the interaction region. This region has a conventional triple-deck structure. To
study the interactive flow one has to solve simultaneously the Prandtl boundary-layer
equations in the lower deck which occupies a thin viscous sublayer near the body
surface and the Kármán–Guderley equations for the upper deck situated in the inviscid
flow outside the boundary layer. In this paper a numerical solution of the interaction
problem is constructed for the case when the separation region is entirely contained
within the viscous sublayer and the inviscid part of the flow remains marginally
supersonic. The solution proves to be non-unique, revealing a hysteresis character of
the flow in the interaction region.
Inhibition of cytokine‐induced JAK‐STAT signalling pathways by an endonuclease inhibitor aurintricarboxylic acid
Authors: Chen Ching‐Wen , Chao Yee , Chang Ying‐Hsin , Hsu Ming‐Jen , Lin Wan‐Wan
Published: November 2002

Inducible nitric oxide (iNOS) is thought to involve in host defence and tissue damage in inflammatory loci. In previous study, we have found that the endonuclease inhibitor aurintricarboxylic acid (ATA) can protect macrophages from cell death induced by bacterial lipopolysaccharide. This action is through the interruption with signalling pathways for NF‐κB and AP‐1 activation, and thus iNOS expression. In this study we have addressed the effects of ATA on JAK‐STAT signalling pathways.

In murine RAW 264.7 macrophages, IFN‐γ‐mediated NO production and iNOS expression were concentration‐dependently reduced by the presence of 3–100 μM ATA.

IFN‐γ‐induced STAT1 activation, as assessed from its tyrosine phosphorylation, nuclear translocation, binding to specific DNA response element and evoked IRF‐1 reporter gene assay, were concomitantly inhibited by ATA. However, ATA did not alter IFN‐γ binding to RAW 264.7 cells.

The activities of JAK1 and JAK2, the upstream kinases essential for STAT1 signalling in response to IFN‐γ, were also reduced by ATA.

Moreover, IL‐4, IL‐10, GM‐CSF and M‐CSF elicited tyrosine phosphorylation of STAT3, STAT5 and/or STAT6 in macrophages were diminished by the presence of ATA.

Taken together, we conclude that ATA can interfere JAK‐STAT signalling pathways in response to cytokines. This action contributes to the inhibition of IFN‐γ‐induced iNOS expression.

British Journal of Pharmacology (2002) 137, 1011–1020. doi:10.1038/sj.bjp.0704955
T cell selective apoptosis by a novel immunosuppressant, FTY720, is closely regulated with Bcl‐2
Authors: Nagahara Yukitoshi , Ikekita Masahiko , Shinomiya Takahisa
Published: November 2002

A novel immunosuppressant FTY720 caused a significant decrease in peripheral T lymphocytes, but not in B lymphocytes upon oral administration. This decrease was mainly a result of FTY720‐induced apoptosis. In this study, we confirmed FTY720‐induced T cell selective apoptosis using lymphoma cell lines in vitro.

Viability loss, DNA fragmentation, Annexin V binding, and caspases activation (caspase‐3, ‐8, and ‐9) were observed in Jurkat cells (T lymphoma cells), but not significantly in BALL‐1 cells (B lymphoma cells). These results indicated that FTY720 selectively induced apoptosis in T cell lymphoma to a greater extent than in B cell lymphoma, a finding that is similar to the result observed when FTY720 was treated with T lymphocytes and B lymphocytes in vitro.

FTY720 released cytochrome c from mitochondria in Jurkat intact cells as well as from isolated Jurkat mitochondria directly, but not from mitochondria in BALL‐1 cells nor from isolated BALL‐1 mitochondria.

BALL‐1 cells and B cells had more abundant mitochondria‐localized anti‐apoptotic protein Bcl‐2 than did Jurkat cells and T cells.

FTY720‐induced apoptosis is inhibited by the overexpression of Bcl‐2, suggesting that the cellular Bcl‐2 level regulates the sensitivity to FTY720.

British Journal of Pharmacology (2002) 137, 953–962. doi:10.1038/sj.bjp.0704970
Transcriptome analysis during cell division in plants
Authors: Breyne Peter , Dreesen Rozemarijn , Vandepoele Klaas , De Veylder Lieven , Van Breusegem Frank , Callewaert Lindy , Rombauts Stephane , Raes Jeroen , Cannoot Bernard , Engler Gilbert , Inzé Dirk , Zabeau Marc
Published: November 2002

Using synchronized tobacco Bright Yellow-2 cells and cDNA-amplified fragment length polymorphism-based genomewide expression analysis, we built a comprehensive collection of plant cell cycle-modulated genes. Approximately 1,340 periodically expressed genes were identified, including known cell cycle control genes as well as numerous unique candidate regulatory genes. A number of plant-specific genes were found to be cell cycle modulated. Other transcript tags were derived from unknown plant genes showing homology to cell cycle-regulatory genes of other organisms. Many of the genes encode novel or uncharacterized proteins, indicating that several processes underlying cell division are still largely unknown.
The catalytic cycle of β-lactam synthetase observed by x-ray crystallographic snapshots
Authors: Miller Matthew T. , Bachmann Brian O. , Townsend Craig A. , Rosenzweig Amy C.
Published: November 2002

The catalytic cycle of the ATP/Mg
2+
-dependent enzyme β-lactam synthetase (β-LS) from
Streptomyces clavuligerus
has been observed through a series of x-ray crystallographic snapshots. Chemistry is initiated by the ordered binding of ATP/Mg
2+
and
N
2
-(carboxyethyl)-
l
-arginine (CEA) to the apoenzyme. The apo and ATP/Mg
2+
structures described here, along with the previously described CEA⋅α,β-methyleneadenosine 5′-triphosphate (CEA⋅AMP-CPP)/Mg
2+
structure, illuminate changes in active site geometry that favor adenylation. In addition, an acyladenylate intermediate has been trapped. The substrate analog
N
2
-(carboxymethyl)-
l
-arginine (CMA) was adenylated by ATP in the crystal and represents a close structural analog of the previously proposed CEA-adenylate intermediate. Finally, the structure of the ternary product complex deoxyguanidinoproclavaminic acid (DGPC)⋅AMP/PP
i
/Mg
2+
has been determined. The CMA-AMP/PP
i
/Mg
2+
and DGPC⋅AMP/PP
i
/Mg
2+
structures reveal interactions in the active site that facilitate β-lactam formation. All of the ATP-bound structures differ from the previously described CEA⋅AMP-CPP/Mg
2+
structure in that two Mg
2+
ions are found in the active sites. These Mg
2+
ions play critical roles in both the adenylation and β-lactamization reactions.
Transcriptional activating regions target a cyclin-dependent kinase
Authors: Ansari Aseem Z. , Koh Sang Seok , Zaman Zafar , Bongards Christine , Lehming Norbert , Young Richard A. , Ptashne Mark
Published: November 2002

Several yeast activators are phosphorylated by SRB10, a cyclin-dependent kinase associated with the transcriptional machinery. Sites of phosphorylation are found outside the activating region in each case, and the modification has different physiological consequences in different cases. We show here that certain acidic transcriptional activating regions contact SRB10 as assayed both
in vivo
and
in vitro
. The interaction evidently positions each activator, as it activates transcription, so that it gets phosphorylated by SRB10, and thus a common mechanism targets disparate substrates to the kinase.
Expression of human epileptic temporal lobe neurotransmitter receptors inXenopusoocytes: An innovative approach to study epilepsy
Authors: Palma Eleonora , Esposito Vincenzo , Mileo Anna Maria , Di Gennaro Giancarlo , Quarato Pierpaolo , Giangaspero Felice , Scoppetta Ciriaco , Onorati Paolo , Trettel Flavia , Miledi Ricardo , Eusebi Fabrizio
Published: November 2002

Poly(A+) RNA was extracted from the temporal lobe (TL) of medically intractable epileptic patients which underwent surgical TL resection. Injection of this mRNA intoXenopusoocytes led to the expression of ionotropic receptors for γ-aminobutyric acid (GABA), kainate (KAI) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). Membrane currents elicited by GABA inverted polarity at −15 mV, close to the oocyte's chloride equilibrium potential, were inhibited by bicuculline, and were potentiated by pentobarbital and flunitrazepam. These basic characteristics were also displayed by GABA currents elicited in oocytes injected with mRNAs isolated from human TL glioma (TLG) or from mouse TL. However, the GABA receptors expressed by the epileptic TL mRNA exhibited some unusual properties, consisting in a rapid current run-down after repetitive GABA applications and a large EC50(125 μM). AMPA alone evoked very small or nil currents, whereas KAI induced larger currents. Nevertheless, upon cyclothiazide treatment, AMPA elicited substantial currents that, like the KAI currents, were inhibited by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Furthermore, the glutamate receptor 5 (GluR5) agonist, ATPA, failed to evoke an obvious current although both RT-PCR and Western blot analyses showed GluR5 expression in the epileptic TL. Oocytes injected with mouse TL or human TLG mRNAs generated KAI and AMPA currents similar to those evoked in oocytes injected with epileptic TL mRNA but, in contrast to these, the mouse TL and human TLG oocytes were also responsive to ATPA. Our findings are in accord with the concept that both a depression of GABA inhibition and a dysfunction of the KAI-receptor system maintain a high neuronal excitability that results in epileptic seizures.
Retroviral delivery of small interfering RNA into primary cells
Authors: Barton Gregory M. , Medzhitov Ruslan
Published: November 2002

RNA interference is an evolutionarily conserved process in which recognition of double-stranded RNA ultimately leads to posttranscriptional suppression of gene expression. This suppression is mediated by short (21- to 22-nt) small interfering RNAs (siRNAs), which induce degradation of mRNA based on complementary base pairing. The silencing of gene expression by siRNAs is emerging rapidly as a powerful method for genetic analysis. Recently, several groups have reported systems designed to express siRNAs in mammalian cells through transfection of either oligonucleotides or plasmids encoding siRNAs. Because these systems rely on transfection for delivery, the cell types available for study are restricted generally to transformed cell lines. Here, we describe a retroviral system for delivery of siRNA into cells. The use of retroviral vectors can greatly expand the types of cells available for RNA interference analysis. Furthermore, we demonstrate that this retroviral system allows for stable inactivation of genes in primary cells.
The Two ADF-H Domains of Twinfilin Play Functionally Distinct Roles in Interactions with Actin Monomers
Authors: Ojala Pauli J. , Paavilainen Ville O. , Vartiainen Maria K. , Tuma Roman , Weeds Alan G. , Lappalainen Pekka
Published: November 2002

Twinfilin is a ubiquitous and abundant actin monomer–binding protein that is composed of two ADF-H domains. To elucidate the role of twinfilin in actin dynamics, we examined the interactions of mouse twinfilin and its isolated ADF-H domains with G-actin. Wild-type twinfilin binds ADP-G-actin with higher affinity (KD= 0.05 μM) than ATP-G-actin (KD= 0.47 μM) under physiological ionic conditions and forms a relatively stable (koff= 1.8 s−1) complex with ADP-G-actin. Data from native PAGE and size exclusion chromatography coupled with light scattering suggest that twinfilin competes with ADF/cofilin for the high-affinity binding site on actin monomers, although at higher concentrations, twinfilin, cofilin, and actin may also form a ternary complex. By systematic deletion analysis, we show that the actin-binding activity is located entirely in the two ADF-H domains of twinfilin. Individually, these domains compete for the same binding site on actin, but the C-terminal ADF-H domain, which has >10-fold higher affinity for ADP-G-actin, is almost entirely responsible for the ability of twinfilin to increase the amount of monomeric actin in cosedimentation assays. Isolated ADF-H domains associate with ADP-G-actin with rapid second-order kinetics, whereas the association of wild-type twinfilin with G-actin exhibits kinetics consistent with a two-step binding process. These data suggest that the association with an actin monomer induces a first-order conformational change within the twinfilin molecule. On the basis of these results, we propose a kinetic model for the role of twinfilin in actin dynamics and its possible function in cells.
Functional Proteomic Analysis of Human Nucleolus
Authors: Scherl Alexander , Couté Yohann , Déon Catherine , Callé Aleth , Kindbeiter Karine , Sanchez Jean-Charles , Greco Anna , Hochstrasser Denis , Diaz Jean-Jacques
Published: November 2002

The notion of a “plurifunctional” nucleolus is now well established. However, molecular mechanisms underlying the biological processes occurring within this nuclear domain remain only partially understood. As a first step in elucidating these mechanisms we have carried out a proteomic analysis to draw up a list of proteins present within nucleoli of HeLa cells. This analysis allowed the identification of 213 different nucleolar proteins. This catalog complements that of the 271 proteins obtained recently by others, giving a total of ∼350 different nucleolar proteins. Functional classification of these proteins allowed outlining several biological processes taking place within nucleoli. Bioinformatic analyses permitted the assignment of hypothetical functions for 43 proteins for which no functional information is available. Notably, a role in ribosome biogenesis was proposed for 31 proteins. More generally, this functional classification reinforces the plurifunctional nature of nucleoli and provides convincing evidence that nucleoli may play a central role in the control of gene expression. Finally, this analysis supports the recent demonstration of a coupling of transcription and translation in higher eukaryotes.
Meiotic Cohesion Requires Accumulation of ORD on Chromosomes before Condensation
Authors: Balicky Eric M. , Endres Matthew W. , Lai Cary , Bickel Sharon E.
Published: November 2002

Cohesion between sister chromatids is a prerequisite for accurate chromosome segregation during mitosis and meiosis. To allow chromosome condensation during prophase, the connections that hold sister chromatids together must be maintained but still permit extensive chromatin compaction. In Drosophila, null mutations in the orientation disruptor (ord) gene lead to meiotic nondisjunction in males and females because cohesion is absent by the time that sister kinetochores make stable microtubule attachments. We provide evidence that ORD is concentrated within the extrachromosomal domains of the nuclei ofDrosophila primary spermatocytes during early G2, but accumulates on the meiotic chromosomes by mid to late G2. Moreover, using fluorescence in situ hybridization to monitor cohesion directly, we show that cohesion defects first become detectable inordnullspermatocytes shortly after the time when wild-type ORD associates with the chromosomes. After condensation, ORD remains bound at the centromeres of wild-type spermatocytes and persists there until centromeric cohesion is released during anaphase II. Our results suggest that association of ORD with meiotic chromosomes during mid to late G2 is required to maintain sister-chromatid cohesion during prophase condensation and that retention of ORD at the centromeres after condensation ensures the maintenance of centromeric cohesion until anaphase II.
LIMITS ON THE DETECTABILITY OF COSMIC TOPOLOGY IN HYPERBOLIC UNIVERSES
Authors: GOMERO G. I. , REBOUÇAS M. J. , TAVAKOL R.
Published: November 2002

We reexamine the possibility of the detection of the cosmic topology in nearly flat hyperbolic Friedmann-Lemaître-Robertson-Walker (FLRW) universes by using patterns repetition. We update and extend our recent results in two important ways: by employing recent observational constraints on the cosmological density parameters as well as the recent mathematical results concerning small hyperbolic 3-manifolds. This produces new bounds with consequences for the detectability of the cosmic topology. In addition to obtaining new bounds, we also give a concrete example of the sensitive dependence of detectability of cosmic topology on the uncertainties in the observational values of the density parameters.
EXPERIMENTAL STATUS OF CORRECTIONS TO NEWTONIAN GRAVITATION INSPIRED BY EXTRA DIMENSIONS
Authors: MOSTEPANENKO V. M.
Published: November 2002

Corrections to Newtonian gravitation inspired by the extra dimensional physics and by the exchange of light and massless elementary particles between the atoms of two macrobodies are considered. These corrections can be described by the potentials of Yukawa-type and by the power-type potentials with different powers. The strongest up to date constraints on the corrections to Newtonian gravitation are collected following from the Eötvos- and Cavendish-type experiments and also from the measurements of the Casimir and van der Waals force.
COLD DARK MATTER AND PRIMORDIAL SUPERHEAVY PARTICLES
Authors: GRIB A. A. , PAVLOV YU. V.
Published: November 2002

The hypothesis that cold dark matter consists of primordial superheavy particles, the decay of short lifetime component of which led to the observable mass of matter while long living component survived up to modern times manifesting its presence in high energetic cosmic rays particles is investigated.
REGULAR INFLATIONARY COSMOLOGICAL MODELS IN GENERAL RELATIVITY THEORY AND GAUGE THEORIES OF GRAVITATION
Authors: MINKEVICH A. V.
Published: November 2002

Numerical analysis of some regular inflationary cosmological models built in the framework of general relativity theory as well as gauge theories of gravitation is given. Dependence of some their characteristics on initial conditions at the bounce is discussed.
ARTIFICIAL METAL NANOCLUSTER CRYSTALS
Authors: JIA JIN-FENG , LIU X. , LI S. C. , WANG J. Z. , LI J. L. , LIU H. , PAN M. H. , DOU R. F. , XUE QI-KUN , LI ZHI-QIANG , ZHANG S. B.
Published: November 2002

Artificial metal nanocluster crystals, (i.e. periodic lattices consisting of identical metal nanoclusters) were fabricated using a novel technique in which surface mediated magic clustering was used to achieve identical cluster size, while the Si(111)-7 × 7 surface was used as a template for ordering the clusters. The universality of this strategy was demonstrated by fabricating more than 10 different nanocluster arrays with different metals and alloys. The atomic structures, formation mechanism and stability of the nanoclusters were studied with in situ scanning tunneling microscopy combined with first-principles total energy calculations. Our study shows that delicate control of growth kinetics is extremely important for cluster crystal fabrication.
QUANTUM INTEGRABLE SYSTEM WITH MULTI-COMPONENTS IN TWO DIMENSIONS
Authors: YAN MU-LIN , ZHAO BAO-HENG
Published: November 2002

A quantum N-body problem with 2-component in (2 + 1) dimensions deduced from an integrable model in (2 + 1) dimensions is investigated. The Davey–Stewartson 1 (DS1) system9 is an integrable model in two dimensions. A quantum DS1 system with 2 color components in two dimensions has been formulated. This two-dimensional problem has been reduced to two one-dimensional many-body problems with 2 color components. The solutions of the two-dimensional problem under consideration has been constructed from the resulting problems in one dimension. For the latter with δ-function interactions and being solved by the Bethe–Yang ansatz, we introduce symmetrical and anti-symmetrical Young operators of the permutation group and obtain the exact solutions for the quantum DS1 system. The application of the solutions is discussed.
Preoperative Glutamine Administration Induces Heat-Shock Protein 70 Expression and Attenuates Cardiopulmonary Bypass–Induced Inflammatory Response by Regulating Nitric Oxide Synthase Activity
Authors: Hayashi Yoshitaka , Sawa Yoshiki , Fukuyama Naoto , Nakazawa Hiroe , Matsuda Hikaru
Published: November 2002

Background—

Heat-shock protein 70 (HSP70) plays a major role in the pathophysiology of inflammation, and the induction of HSP70 before the onset of inflammation can reduce organ damage through a self-protective system. Glutamine is known to be an inducer of HSP70, and its preoperative administration seems useful in attenuating cardiopulmonary bypass (CPB)–induced inflammatory response.

Methods and Results—

Adult male Sprague-Dawley rats (group G, received 100 mg/kg of glutamine via the right jugular vein 3 times per day for 1 week and just before the initiation of CPB; group C served as control) underwent CPB (60 minutes, 100 mL/kg per minute, 34°C) and were killed 3 hours after the termination of CPB. Group G showed significantly lower plasma concentrations of interleukin-6 and interleukin-8 after CPB termination. Myocardial and respiratory damages were significantly attenuated in group G, as evidenced by Langendorff perfusion, respiratory index, and neutrophil adherence. HSP70 expressions in the heart, lung, and liver were detected only in group G before CPB and were markedly stronger in group G 3 hours after CPB termination. Although plasma nitrate+nitrite concentrations were not significantly different between the groups, endothelial-constitutive nitric oxide synthase (NOS) activity was markedly preserved and inducible NOS activity was markedly attenuated in the tissues of group G.

Conclusions—

These results suggest that preoperative glutamine administration induces HSP70 expression before CPB and attenuates CPB-induced inflammation by regulating NOS activity, which may be a prospective management for conferring tolerance to CPB-induced inflammatory response through a self-protective mechanism.
Chemistry of the vulcanization and protection of elastomers: A review of the achievements
Authors: Coran A. Y.
Published: November 2002

The chemistry of vulcanization and its effects on vulcanizate properties are reviewed. Also, the chemistry of the protection of rubber vulcanizates from the effects of oxidation and ozonation is reviewed. © 2002 Wiley Periodicals, Inc. J Appl Polm Sci 87:24–30, 2003