bluuebunny/crossref_metadata_2025 huggingface dataset:
Ran-independent nuclear import of cyclin B1–Cdc2 by importin β
Authors: Takizawa Catherine G. , Weis Karsten , Morgan David O.
Published: July 2002

Mitosis is triggered in vertebrate cells by the cyclin B1–Cdc2 complex. The activation of this complex at the end of G
2
phase is accompanied by its translocation from the cytoplasm to the nucleus. We used digitonin-permeabilized human cells to analyze the mechanism by which cyclin B1–Cdc2 is imported into the nucleus. Cyclin B1–Cdc2 import was not blocked by inhibitors of the importin α-dependent import pathway or by dominant negative versions of the GTPase Ran or importin β. However, the rate of cyclin B1 import was decreased by immunodepletion of importin β from cytosol. Purified importin β promoted cyclin B1 import in the absence of cytosol or Ran and in the presence of the dominant negative Ran mutant. We conclude that cyclin B1 import is mediated by an unusual importin β-dependent mechanism that does not require Ran.
The agricultural pathology of ant fungus gardens
Authors: Currie Cameron R. , Mueller Ulrich G. , Malloch David
Published: July 2002

Gardens of fungus-growing ants (Formicidae: Attini) traditionally have been thought to be free of microbial parasites, with the fungal mutualist maintained in nearly pure “monocultures.” We conducted extensive isolations of “alien” (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants. Contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites that are only known from attine gardens and that are found in most attine nests. These specialized garden parasites, belonging to the microfungus genus
Escovopsis
(Ascomycota: anamorphic Hypocreales), are horizontally transmitted between colonies. Consistent with theory of virulence evolution under this mode of pathogen transmission,
Escovopsis
is highly virulent and has the potential for rapid devastation of ant gardens, leading to colony mortality. The specialized parasite
Escovopsis
is more prevalent in gardens of the more derived ant lineages than in gardens of the more “primitive” (basal) ant lineages. Because fungal cultivars of derived attine lineages are asexual clones of apparently ancient origin whereas cultivars of primitive ant lineages were domesticated relatively recently from free-living sexual stocks, the increased virulence of pathogens associated with ancient asexual cultivars suggests an evolutionary cost to cultivar clonality, perhaps resulting from slower evolutionary rates of cultivars in the coevolutionary race with their pathogens.
Proteolytic enzymes, past and future
Authors: Neurath Hans
Published: July 2002

Today’s knowledge is based on yesterday’s research, which, for
me, started some 60 years ago. In the introduction to this colloquium,
the past history of proteolytic enzymes is briefly reviewed against the
background of simultaneously developing concepts and methodologies in
protein chemistry. This history is followed by a sketch of more recent
developments of the role of proteolytic enzymes in physiological
regulation and an outlook of future trends apparent from current
research.
Double duplex invasion by peptide nucleic acid: A general principle for sequence-specific targeting of double-stranded DNA
Authors: Lohse Jesper , Dahl Otto , Nielsen Peter E.
Published: July 2002

Pseudocomplementary PNAs containing diaminopurine⋅thiouracil base pairs have been prepared and are shown to bind with high specificity and efficiency to complementary targets in double-stranded DNA by a mechanism termed “double duplex invasion” in which the duplex is unwound and both DNA strands are targeted simultaneously, each by one of the two pseudocomplementary peptide nucleic acids (PNAs). On the basis of our results we predict that (for decameric targets) more than 80% of all sequences can be targeted by straightforward Watson–Crick base pairing by using this approach in its present form. Targeting of pseudocomplementary PNAs to the promoter of the T7 phage RNA polymerase effectively inhibits transcription initiation. These results have important implications in the development of gene therapeutic agents as well as for genetic diagnostic and molecular biology applications.
Regulation of nuclear translocation of Forkhead transcription factor AFX by protein kinase B
Authors: Takaishi Hiroshi , Konishi Hiroaki , Matsuzaki Hidenori , Ono Yoshitaka , Shirai Yasuhito , Saito Naoaki , Kitamura Tadahiro , Ogawa Wataru , Kasuga Masato , Kikkawa Ushio , Nishizuka Yasutomi
Published: July 2002

The regulation of intracellular localization of AFX, a human Forkhead transcription factor, was studied. AFX was recovered as a phosphoprotein from transfected COS-7 cells growing in the presence of FBS, and the phosphorylation was eliminated by wortmannin, a potent inhibitor of phosphatidylinositol (PI) 3-kinase. AFX was phosphorylated
in vitro
by protein kinase B (PKB), a downstream target of PI 3-kinase, but a mutant protein in which three putative phosphorylation sites of PKB had been replaced by Ala was not recognized by PKB. In Chinese hamster ovary cells (CHO-K1) cultured with serum, the AFX protein fused with green fluorescence protein (AFX-GFP) is localized mainly in the cytoplasm, and wortmannin induced transient nuclear translocation of the fusion protein. The AFX-GFP mutant in which all three phosphorylation sites had been replaced by Ala was detected exclusively in the cell nucleus. AFX-GFP was in the nucleus when the cells were infected with an adenovirus vector encoding a dominant-negative form of either PI 3-kinase or PKB, whereas the fusion protein stayed in the cytoplasm when the cells expressed constitutively active PKB. In CHO-K1 cells expressing AFX-GFP, DNA fragmentation was induced by the stable PI 3-kinase inhibitor LY294002, and the expression of the active form of PKB suppressed this DNA fragmentation. The phosphorylation site mutant of AFX-GFP enhanced DNA fragmentation irrespective of the presence and absence of PI 3-kinase inhibitor. These results indicate that the nuclear translocation of AFX is negatively regulated through its phosphorylation by PKB.
Three metal ions at the active site of the
Tetrahymena
group I ribozyme
Authors: Shan Shu-ou , Yoshida Aiichiro , Sun Sengen , Piccirilli Joseph A. , Herschlag Daniel
Published: July 2002

Metal ions are critical for catalysis by many RNA and protein enzymes. To understand how these enzymes use metal ions for catalysis, it is crucial to determine how many metal ions are positioned at the active site. We report here an approach, combining atomic mutagenesis with quantitative determination of metal ion affinities, that allows individual metal ions to be distinguished. Using this approach, we show that at the active site of the
Tetrahymena
group I ribozyme the previously identified metal ion interactions with three substrate atoms, the 3′-oxygen of the oligonucleotide substrate and the 3′- and 2′-moieties of the guanosine nucleophile, are mediated by three distinct metal ions. This approach provides a general tool for distinguishing active site metal ions and allows the properties and roles of individual metal ions to be probed, even within the sea of metal ions bound to RNA.
A protein residing at the subunit interface of the bacterial ribosome
Authors: Agafonov Dmitry E. , Kolb Vyacheslav A. , Nazimov Igor V. , Spirin Alexander S.
Published: July 2002

Surface labeling of
Escherichia coli
ribosomes with the use of the tritium bombardment technique has revealed a minor unidentified ribosome-bound protein (spot Y) that is hidden in the 70S ribosome and becomes highly labeled on dissociation of the 70S ribosome into subunits. In the present work, the N-terminal sequence of the protein Y was determined and its gene was identified as
yfia
, an ORF located upstream the
phe
operon of
E. coli
. This 12.7-kDa protein was isolated and characterized. An affinity of the purified protein Y for the 30S subunit, but not for the 50S ribosomal subunit, was shown. The protein proved to be exposed on the surface of the 30S subunit. The attachment of the 50S subunit resulted in hiding the protein Y, thus suggesting the protein location at the subunit interface in the 70S ribosome. The protein was shown to stabilize ribosomes against dissociation. The possible role of the protein Y as ribosome association factor in translation is discussed.
Detection of protein fold similarity based on correlation of amino acid properties
Authors: Grigoriev Igor V. , Kim Sung-Hou
Published: July 2002

An increasing number of proteins with weak sequence similarity have been found to assume similar three-dimensional fold and often have similar or related biochemical or biophysical functions. We propose a method for detecting the fold similarity between two proteins with low sequence similarity based on their amino acid properties alone. The method, the proximity correlation matrix (PCM) method, is built on the observation that the physical properties of neighboring amino acid residues in sequence at structurally equivalent positions of two proteins of similar fold are often correlated even when amino acid sequences are different. The hydrophobicity is shown to be the most strongly correlated property for all protein fold classes. The PCM method was tested on 420 proteins belonging to 64 different known folds, each having at least three proteins with little sequence similarity. The method was able to detect fold similarities for 40% of the 420 sequences. Compared with sequence comparison and several fold-recognition methods, the method demonstrates good performance in detecting fold similarities among the proteins with low sequence identity. Applied to the complete genome of
Methanococcus jannaschii
, the method recognized the folds for 22 hypothetical proteins.
The α-helical FXXΦΦ motif in p53: TAF interaction and discrimination by MDM2
Authors: Uesugi Motonari , Verdine Gregory L.
Published: July 2002

Transcriptional activation domains share little sequence homology and generally lack folded structures in the absence of their targets, aspects that have rendered activation domains difficult to characterize. Here, a combination of biochemical and nuclear magnetic resonance experiments demonstrates that the activation domain of the tumor suppressor p53 has an FXXΦΦ motif (F, Phe; X, any amino acids; Φ, hydrophobic residues) that folds into an α-helix upon binding to one of its targets, hTAF
II
31 (a human TFIID TATA box-binding protein-associated factor). MDM2, the cellular attenuator of p53, discriminates the FXXΦΦ motif of p53 from those of NF-κB p65 and VP16 and specifically inhibits p53 activity. Our studies support the notion that the FXXΦΦ sequence is a general α-helical recognition motif for hTAF
II
31 and provide insights into the mechanistic basis for regulation of p53 function.
Inhibition of growth, production of insulin-like growth factor-II (IGF-II), and expression of IGF-II mRNA of human cancer cell lines by antagonistic analogs of growth hormone-releasing hormone
in vitro
Authors: Csernus Valér J. , Schally Andrew V. , Kiaris Hippokratis , Armatis Patricia
Published: July 2002

Antagonistic analogs of growth hormone-releasing hormone (GHRH) suppress growth of various tumors
in vivo
. This effect is exerted in part through inhibition of the GHRH–GH–insulin-like growth factor (IGF)-I axis. Nevertheless, because autocrine/paracrine control of proliferation by IGF-II also is a major factor in many tumors, the interference with this growth-stimulating pathway would offer another approach to tumor control. We thus investigated whether GHRH antagonists MZ-4-71 and MZ-5-156 also act on the tumor cells directly by blocking the production of IGF-II. An increase in the IGF-II concentration in the media during culture was found in 13 of 26 human cancer cell lines tested. Reverse transcription–PCR studies on 8 of these cell lines showed that they also expressed IGF-II mRNA. Antagonists of GHRH significantly inhibited the rate of proliferation of mammary (MDA-MB-468 and ZR-75–1), prostatic (PC-3 and DU-145), and pancreatic (MiaPaCa-2, SW-1990, and Capan-2) cancer cell lines as shown by colorimetric and [
3
H]thymidine incorporation tests and reduced the expression of IGF-II mRNA in the cells and the concentration of IGF-II secreted into the culture medium. Growth and IGF-II production of lung (H-23 and H-69) and ovarian (OV-1063) cancer cells that express mRNA for IGF-II and excrete large quantities of IGF-II also was marginally suppressed by the antagonists. These findings suggest that antagonistic analogs of GHRH can inhibit growth of certain tumors not only by inhibiting the GHRH–GH–IGF-I axis, but also by reducing the IGF-II production and by interfering with the autocrine regulatory pathway.
Corticotropin-releasing hormone causes antidiuresis and antinatriuresis by stimulating vasopressin and inhibiting atrial natriuretic peptide release in male rats
Authors: Gutkowska J. , Jankowski M. , Mukaddam-Daher S. , McCann S. M.
Published: July 2002

In both normally hydrated and volume-expanded rats, there was a biphasic effect of corticotropin-releasing hormone (CRH) (1–10 μg, i.v.) on renal function. Within the first hour, CRH caused antidiuresis, antinatriuresis, and antikaliuresis together with reduction in urinary cGMP output that, in the fourth hour, were replaced by diuresis, natriuresis, and kaliuresis accompanied by increased cGMP output. Plasma arginine vasopressin (AVP) concentrations increased significantly within 5 min, reached a peak at 15 min, and declined by 30 min to still-elevated values maintained for 180 min. Changes in plasma atrial natriuretic peptide (ANP) were the mirror image of those of AVP. Plasma ANP levels were correlated with decreased ANP in the left ventricle at 30 min and increased ANP mRNA in the right atrium at 180 min. All urinary changes were reversed by a potent AVP type 2 receptor (V
2
R) antagonist. Control 0.9% NaCl injections evoked an immediate increase in blood pressure and heart rate measured by telemetry within 3–5 min. This elevation of blood pressure was markedly inhibited by CRH (5 μg). We hypothesize that the effects are mediated by rapid, direct vasodilation induced by CRH that decreases baroreceptor input to the brain stem, leading to a rapid release of AVP that induces the antidiuresis by direct action on the V
2
Rs in the kidney. Simultaneously, acting on V
2
Rs in the heart, AVP inhibits ANP release and synthesis, resulting in a decrease in renal cGMP output that is responsible for the antinatriuretic and antikaliuretic effects.
Identification of the single-strand telomeric DNA binding domain of the
Saccharomyces cerevisiae
Cdc13 protein
Authors: Hughes Timothy R. , Weilbaecher Rodney G. , Walterscheid Monika , Lundblad Victoria
Published: July 2002

The
CDC13
gene of
Saccharomyces cerevisiae
is required both to protect telomeric DNA and to ensure proper function of yeast telomerase
in vivo
. We have previously demonstrated that Cdc13p has a high affinity single-strand telomeric DNA binding activity, although the primary amino acid sequence of Cdc13p has no previously characterized DNA binding motifs. We report here mapping of the Cdc13 DNA binding domain by a combination of proteolysis mapping and deletion cloning. The DNA binding domain maps to residues 557–694 of the 924-amino acid Cdc13 polypeptide, within the most basic region of Cdc13p. A slightly larger version of this domain can be efficiently expressed in
Escherichia coli
as a soluble small protein, with DNA binding properties comparable to those of the full-length protein. A single amino acid missense mutation within this domain results in thermolabile DNA binding and conditional lethality in yeast, consistent with the prediction that DNA binding should be essential for
CDC13
function. These results show that Cdc13p contains a discrete substructure responsible for DNA binding and should facilitate structural characterization of this telomere binding protein.
Evidence for a linear search in bimolecular 3′ splice site AG selection
Authors: Chen Shuyan , Anderson Karin , Moore Melissa J.
Published: July 2002

In most eukaryotic introns the 3′ splice site is defined by a surprisingly short AG consensus found a variable distance downstream of the branch site. Exactly how the spliceosome determines which AG to use, however, is not well understood. Previously we showed that when the branch site and 3′ splice site AG are supplied by separate RNA molecules, there is a strong preference for use of the 5′-most AG in the 3′ splice site-containing RNA. Here we show that this apparent 5′→3′ directionality holds even when this RNA contains four tandem repeats of a 6-nt sequence containing AG. Exactly the same pattern of 3′ splice site choice was observed when the same tandem repeats were incorporated into a full-length splicing substrate. When the 3′ splice site AG is supplied by a separate RNA, that RNA must be linear with an unobstructed 5′ end. Similarly, the branch-containing RNA must be truncated immediately 3′ to the polypyrimidine tract. A model is presented that incorporates these observations and reconciles previously proposed mechanisms for 3′ splice site selection.
Strategy for monitoring T cell responses to NY-ESO-1 in patients with any HLA class I allele
Authors: Gnjatic Sacha , Nagata Yasuhiro , Jäger Elke , Stockert Elisabeth , Shankara Srinivas , Roberts Bruce L. , Mazzara Gail P. , Lee Sang Yull , Dunbar P. Rod , Dupont Bo , Cerundolo Vincenzo , Ritter Gerd , Chen Yao-Tseng , Knuth Alexander , Old Lloyd J.
Published: July 2002

NY-ESO-1 elicits frequent antibody responses in cancer patients, accompanied by strong CD8+T cell responses against HLA-A2-restricted epitopes. To broaden the range of cancer patients who can be assessed for immunity to NY-ESO-1, a general method was devised to detect T cell reactivity independent of prior characterization of epitopes. A recombinant adenoviral vector encoding the full cDNA sequence of NY-ESO-1 was used to transduce CD8-depleted peripheral blood lymphocytes as antigen-presenting cells. These modified antigen-presenting cells were then used to restimulate memory effector cells against NY-ESO-1 from the peripheral blood of cancer patients. Specific CD8+T cells thus sensitized were assayed on autologous B cell targets infected with a recombinant vaccinia virus encoding NY-ESO-1. Strong polyclonal responses were observed against NY-ESO-1 in antibody-positive patients, regardless of their HLA profile. Because the vectors do not cross-react immunologically, only responses to NY-ESO-1 were detected. The approach described here allows monitoring of CD8+T cell responses to NY-ESO-1 in the context of various HLA alleles and has led to the definition of NY-ESO-1 peptides presented by HLA-Cw3 and HLA-Cw6 molecules.
A mitochondrial ferredoxin is essential for biogenesis of cellular iron-sulfur proteins
Authors: Lange Heike , Kaut Anita , Kispal Gyula , Lill Roland
Published: July 2002

Iron-sulfur (Fe/S) cluster-containing proteins catalyze a number of electron transfer and metabolic reactions. The components and molecular mechanisms involved in the assembly of the Fe/S clusters have been identified only partially. In eukaryotes, mitochondria have been proposed to execute a crucial task in the generation of intramitochondrial and extramitochondrial Fe/S proteins. Herein, we identify the essential ferredoxin Yah1p of
Saccharomyces cerevisiae
mitochondria as a central component of the Fe/S protein biosynthesis machinery. Depletion of Yah1p by regulated gene expression resulted in a 30-fold accumulation of iron within mitochondria, similar to what has been reported for other components involved in Fe/S protein biogenesis. Yah1p was shown to be required for the assembly of Fe/S proteins both inside mitochondria and in the cytosol. Apparently, at least one of the steps of Fe/S cluster biogenesis within mitochondria requires reduction by ferredoxin. Our findings lend support to the idea of a primary function of mitochondria in the biosynthesis of Fe/S proteins outside the organelle. To our knowledge, Yah1p is the first member of the ferredoxin family for which a function in Fe/S cluster formation has been established. A similar role may be predicted for the bacterial homologs that are encoded within iron-sulfur cluster assembly (
isc
) operons of prokaryotes.
Mutations in the tumor suppressors Smad2 and Smad4 inactivate transforming growth factor β signaling by targeting Smads to the ubiquitin–proteasome pathway
Authors: Xu Jing , Attisano Liliana
Published: July 2002

Biological signals for transforming growth factor β (TGF-β) are transduced through transmembrane serine/threonine kinase receptors that signal to a family of intracellular mediators known as Smads. Smad2 and Smad4 are important for transcriptional and antiproliferative responses to TGF-β, and their inactivation in human cancers indicates that they are tumor suppressors. A missense mutation at a conserved arginine residue in the amino-terminal MH1 domain of both Smad2 and Smad4 has been identified in tumors from patients with colorectal and pancreatic cancers, respectively. However, the mechanism whereby this mutation interferes with Smad activity is uncertain. Here we show that these mutations do not disrupt activation of Smads, including receptor-mediated phosphorylation of Smad2, Smad2/Smad4 heteromeric complex formation, and Smad nuclear translocation. In contrast, we demonstrate that the mutant Smads are degraded rapidly in comparison with their wild-type counterparts. We show that this decrease in Smad protein stability occurs through induction of Smad ubiquitination by pathways involving the UbcH5 family of ubiquitin ligases. These studies thus reveal a mechanism for tumorigenesis whereby genetic defects in Smads induce their degradation through the ubiquitin-mediated pathway.
Jac1, a mitochondrial J-type chaperone, is involved in the biogenesis of Fe/S clusters in
Saccharomyces cerevisiae
Authors: Voisine Cindy , Cheng Yu C. , Ohlson Maikke , Schilke Brenda , Hoff Kevin , Beinert Helmut , Marszalek Jaroslaw , Craig Elizabeth A.
Published: July 2002

A minor Hsp70 chaperone of the mitochondrial matrix of
Saccharomyces cerevisiae
, Ssq1, is involved in the
formation or repair of Fe/S clusters and/or mitochondrial iron
metabolism. Here, we report evidence that Jac1, a J-type chaperone of
the mitochondrial matrix, is the partner of Ssq1 in this process.
Reduced activity of Jac1 results in a decrease in activity of Fe/S
containing mitochondrial proteins and an accumulation of iron in
mitochondria. Fe/S enzyme activities remain low in both
jac1
and
ssq1
mutant mitochondria even if
normal mitochondrial iron levels are maintained. Therefore, the low
activities observed are not solely due to oxidative damage caused by
excess iron. Rather, these molecular chaperones likely play a direct
role in the normal assembly process of Fe/S clusters.
Platelet-mediated clumping of
Plasmodium falciparum
-infected erythrocytes is a common adhesive phenotype and is associated with severe malaria
Authors: Pain Arnab , Ferguson David J. P. , Kai Oscar , Urban Britta C. , Lowe Brett , Marsh Kevin , Roberts David J.
Published: July 2002

Sequestration of malaria-infected erythrocytes in the peripheral
circulation has been associated with the virulence of
Plasmodium
falciparum
. Defining the adhesive phenotypes of infected
erythrocytes may therefore help us to understand how severe disease is
caused and how to prevent or treat it. We have previously shown that
malaria-infected erythrocytes may form apparent autoagglutinates of
infected erythrocytes. Here we show that such autoagglutination of a
laboratory line of
P. falciparum
is mediated by
platelets and that the formation of clumps of infected erythrocytes and
platelets requires expression of the platelet surface glycoprotein
CD36. Platelet-dependent clumping is a distinct adhesive phenotype,
expressed by some but not all CD36-binding parasite lines, and is
common in field isolates of
P. falciparum
. Finally, we
have established that platelet-mediated clumping is strongly associated
with severe malaria. Precise definition of the molecular basis of this
intriguing adhesive phenotype may help to elucidate the complex
pathophysiology of malaria.
Reliability and Validity of Screening Instruments for Drug and Alcohol Abuse in Adults Seeking Evaluation for Attention‐Deficit/Hyperactivity Disorder
Authors: McCann Barbara S. , Simpson Tracy L. , Ries Richard , Roy‐Byrne Peter
Published: July 2002

A growing number of adults are seeking evaluation for Attention‐Deficit/Hyperactivity Disorder (ADHD). Screening for substance use disorders should be included as part of any comprehensive ADHD evaluation. We describe the validity and reliability of the Drug Abuse Screening Test (DAST) and the Alcohol Use Disorders Identification Test (AUDIT) in adults seeking evaluation for ADHD. Internal reliability estimates were excellent for both instruments. Scores on the DAST and AUDIT were higher among patients with a DSM‐IV diagnosis of current drug abuse or dependence or current alcohol abuse or dependence, respectively. A cutoff score of 6 or above appears to be optimal for identifying individuals who are current drug abusers. A cutoff score of 6 or above on the AUDIT is suggested for detection of current alcohol abuse in this population. Comparable rates of substance use disorders were observed in ADHD and non‐ADHD patients. Both measures are valid and reliable instruments for screening for alcohol and drug abuse among adults seeking evaluation for ADHD.
Changes in mu opioid receptors and rheological properties of erythrocytes among opioid abusers
Authors: ZEIGER ALLEN R. , PATKAR ASHWIN A. , FITZGERALD RAINA , LUNDY ALLAN , BALLAS SAMIR K. , WEINSTEIN STEPHEN P.
Published: July 2002

Abstract Opioids, reported originally to bind to specific receptors in the brain, now also appear to bind to receptors on blood cells. The high prevalence of anemia among chronic opioid users leads us to propose that chronic opiate use results in elevated mu opioid receptor levels on human erythrocytes and that these receptor changes may affect erythrocyte membrane properties. Blood samples from 17 opioid‐dependent subjects (based on the Diagnostic and Statistical Manual of Mental Disorders, 4th edition or DSM‐IV) and 15 drug‐free controls were assayed for mu opioid receptors on erythrocytes using a flow cytometry immunoassay. Deformability and the hydration status of erythrocytes were studied by ektacytometry. Data were analyzed by independent t‐tests, tests of correlation, chi square and cluster analyses. As expected, the percentage of erythrocytes from opioiddependent subjects with opioid receptors (opioid receptor levels) was significantly higher (47.4 ± 38.3%) than controls (22.8 ± 30.1%) (t = 2.01, df = 30, p < 0.05). Also, the opioid‐dependent patients showed a wide variation in the percentage of erythrocytes bearing opioid receptors and data analyses of these patients showed two strongly defined clusters. One subgroup consisted of nine individuals with very high receptor levels (mean = 81.5%) while the other had eight patients with low receptor levels (mean = 9.1%) that were not significantly different than the receptor levels of controls. Ektacytometry of opioid dependent patients with high opioid receptor levels showed changes in rheological parameters of erythrocytes, such as deformability index and cellular hydration. For example, a positive correlation was observed between opioid receptor levels and deformability indices among opioid‐dependent patients (r = 0.74, p < 0.005). Our findings indicate that the mu opioid receptor is present on human erythrocytes, although with considerable variation in receptor levels, and that the levels of this receptor are significantly elevated with chronic opioid exposure. Moreover, erythrocytes with high opioid receptor levels from chronic opiate users seem to have high deformability. This study may offer clues to the biological properties of peripheral blood cells that may be mediated by mu opioid receptors and lead to a better understanding of some of the clinical effects of opioid use.
Analysis of opiates and cocaine by RIA and GC‐MS: distribution of their metabolites in urine and hair from drug addicts
Authors: TABERNERO MARIA JESUS , BERMEJO ANA MARIA , FERNANDEZ PURIFICACION
Published: July 2002

Two analytical techniques (RIA and GC‐MS) were used for the simultaneous identification and determination of heroin, cocaine and their metabolites in the urine and hair of 200 drug addicts. Opiates tests were positive in 182 hair samples and 145 urine samples, whereas cocaine tests were positive in 173 hair samples and in 63 urine samples. Drug content of hair, as determined by RIA, varied over the ranges of 0–30 ng/mg (opiates) and 0–924 ng/mg (cocaine). Metabolite distribution was studied by GC‐MS in samples taken from 50 individuals. Tests revealed 6‐monoacetylmorphine to be ubiquitous in hair and morphine to be the major component in urine. Cocaine was found to invariably occur at higher concentrations than its metabolites in hair with the opposite result in urine.
Psychological impact of the Lidcombe Program of early stuttering intervention
Authors: Woods Sarah , Shearsby Julia , Onslow Mark , Burnham Denis
Published: July 2002

The Lidcombe Program is an operant treatment for stuttering in preschool children for which favourable outcome and social validity data have been published. The treatment involves parental praise for stutter‐free speech in children's everyday speaking environments, and occasional correction of stuttered speech. Theoretical perspectives on the origins of stuttering have prompted suggestions that the Lidcombe Program may have an adverse psychological impact on children. The present preliminary investigation sought to identify any evidence of such a systematic, pernicious trend, which might justify statistically powerful investigations of the issue with large subject numbers. Subjects were eight preschool children who were successfully treated with the Lidcombe Program. The Child Behavior Checklist (CBCL) detected any post‐treatment behavioural markers of changes in children such as anxiety, aggression, withdrawal or depression. The Attachment Q‐Set (AQS) measured any changes in the quality of the attachment relationship between child and mother over the course of treatment. These case studies revealed no evidence of a systematic trend in either. In fact, CBCL data suggested improvements in the children after treatment. It is concluded that there is no reason to doubt that the Lidcombe Program is a safe treatment.
European integration and sociology: The difficult balance between the theoretical, empirical and critical approach1
Authors: Haller Max
Published: July 2002

This is a review article on Goran Therborn's European Modernity and Beyond (1995), one of the most important recent analyses of the ‘Trajectory of European Societies’ in the second half of the twentieth century. The article discusses, by way of example, three general issues treated in Therborn's book: the pattern of socioeconomic development and growth; the issue of European versus national identity; and the (Nordic) welfare state as a model for Europe. Special emphasis is laid on the issue to what degree these processes are specific to Europe and how the theoretical-analytical, empirical and critical functions of sociology can be brought together in a fruitful way.
BLAME OR FATE, INDIVIDUAL OR SOCIAL?
Authors: Oorschot Wim Van , Halman Loek
Published: July 2002

This paper explores popular explanations of poverty. Based on existing theoretical and empirical studies, four types of reason for poverty are distinguished: (1) individual blame; (2) individual fate; (3) social blame; and (4) social fate. Data from the 1990 European Values Study surveys are used to describe and compare cross-nationally the proportions of people perceiving each of the four explanations as a main reason for people living in poverty. Further, it is explored whether or not differential patterns in these perceptions are related to types of welfare regime as distinguished by several authors. One of the main conclusions is that, contrary to prior evidence from Anglo-Saxon countries only, social blame is the most popular explanation of poverty in nearly all of the twenty countries studied. That is, the majority of people living in industrialized welfare states believe that poverty is the outcome of actions of social actors, rather than the inevitable result of individual or social fate. The idea that the poor are themselves to blame for their situation is on average more popular in Eastern European than in Western European countries, where the idea lost ground from the mid-1970s onwards. There is no relation between popular perceptions of poverty and type of welfare state regime. It is suggested that future research should narrow the focus on the relation between poverty perceptions and types of anti-poverty strategy.
LABOR MARKET FLEXIBILITY, SOCIAL PROTECTION AND UNEMPLOYMENT
Authors: Ganßmann Heiner
Published: July 2002

The difference between low unemployment in the USA and high unemployment in continental Europe is frequently attributed to differences in labor market flexibility. European workforces are protected against job and income losses by welfare state programs and protective legislation, which are taken to be responsible for labor market rigidities and, therefore, higher unemployment. The logic of this argument and the evidence supporting it are examined. While US unemployment in general and long-term unemployment in particular have recently been considerably lower than in the large European economies, this is not the case for smaller European economies with extensive welfare states. They provide evidence for the possibility of using social protection not as an obstacle to, but as a means to enhance, flexibility.
RETURN OF THE CROWDS AND RATIONALITY OF ACTION: A history of Russian ‘financial bubbles’ in the mid-1990s
Authors: Radaev Vadim
Published: July 2002

The paper investigates the models of action of small private investors in the Russian ‘financial bubbles’ in 1994-5. The database includes reports of the long-term participant observations (fourteen months) which were carried out on a daily basis by a group of sociologists in the queues at the sales offices of the most famous Russian ‘financial pyramids’ (‘MMM’ and others). The history of the financial game is traced stage by stage. The basic models of actions are classified. Conclusions regarding the rationality and non-rationality of these actions are drawn. A constellation of ideological, economic and organizational factors enabling the crowd formation is analysed.
MODELS OF CROSS-NATIONAL VARIATION IN OCCUPATIONAL SEX SEGREGATION
Authors: Nermo Magnus
Published: July 2002

Cross-national studies of occupational sex segregation have shown not only that industrial countries are markedly segregated by sex, but also that the level of sex segregation varies substantially between countries. The overall aim of this article is to study any association between patterns of cross-national variation in levels of sex segregation and the structuring of welfare states. It represents a new approach to comparative studies of occupational sex segregation as it uses log-linear modelling and comparable micro data from the Luxembourg Employment Study (LES) to describe patterns of sex segregation in the labour market. The results presented here demonstrate some cross-national variation in levels of sex segregation. However, considering substantial cross-national differences in the structure of the welfare state, the relative distribution of women and men in the occupational structure largely follows the same pattern in the Western countries included. Cross-national variation in the structure of the welfare state seems therefore to be of primary importance for understanding the cross-national variation in sex segregation between unpaid labour in the home and paid labour in the market.
WHAT IS ‘SOCIOLOGICAL’ ABOUT THE EURO?
Authors: Dodd Nigel
Published: July 2002

There are no clear precedents for European monetary integration. It would therefore be unwise to rely too closely on evidence drawn from other monetary systems for an indication of where, when and how problems might arise under the new monetary regime. This article comprises four sections. The first deals with issues of economic convergence and the problems associated with viewing the euro zone countries as an optimum currency area. The second moves on to political questions about the accountability of the European Central Bank (ECB) and its credibility in operating a single monetary policy which targets price stability. In the third section, I consider arguments concerning the implications of the relationship between labour mobility and material interest for the workings of a single monetary policy across the euro zone. In the fourth section, I raise broader questions about cultural divergence in economic behaviour within the euro zone.
NOVEL FOOD, NEW MARKETS AND TRUST REGIMES: Responses to the erosion of consumers' confidence in Austria, Italy and the UK
Authors: Sassatelli Roberta , Scott Alan
Published: July 2002

The public debate around food confidence stimulated by food scares, the opening up of wider food markets and the introduction of GM foods provides an opportunity to analyse citizens' identification with their community sociologically, as it is reproduced through mundane practices. In order to do so, this article examines the GM food debate in Italy and the implications for food and agricultural policy of Austria's entry into the EU. Britain, with its highly industrialized agriculture and political commitment to open markets and new technologies, acts as a bench-mark. We distinguish between disembedded and embedded trust regimes; the former being predominant in freer markets and the latter a resource which can be mobilized in cases where remnants of ‘traditional’ agricultural production and supply can still be found (Italy and Austria). The increasing emphasis upon the regional origin of food, its traceability and organic production by key actors - the state, consumers' movements, retailers and marketing boards - we interpret as a confidence-building strategy which attempts to address deficits in disembedded trust resulting from widening chains of interdependency, crises such as BSE and the introduction of unfamiliar new technologies.
INSTITUTIONAL ENTREPRENEURS AND CULTURAL FRAMES: The case of the European Union's Single Market Program
Authors: Fligstein Neil
Published: July 2002

Explaining the emergence of the European Union's Single Market Program requires making sense of how that institutional project came on to the political agenda. This article uses insights from historical and organizational institutional theories to supplement intergovernmentalist and neofunctionalist accounts of the Single Market Program. The European Union was facing a political crisis in the early 1980s caused by an inability of states to find a set of institutional arrangements that were in their collective interest. This crisis enabled the European Commission to act as an institutional entrepreneur in several ways. They produced the Single Market Program as a project, helped build a political coalition to support its basic tenets, and ultimately reorganized the preferences of state actors. The power of the cultural frame approach is that it helps explain how institutional reform and monetary union - projects that were rejected by the states in 1983 - came to be accepted over the decade of the 1980s.
NATIONAL IDENTITIES AND EMOTION IN THE DISCOURSE OF BRITISH MANUFACTURING UNIONS IN THE 1980s AND EARLY 1990s
Authors: Vogler Carolyn
Published: July 2002

This article attempts to explain increasing economic nationalism among British trade unions in the 1980s and early 1990s by linking together approaches from two disciplines which are usually pursued separately, namely psychoanalysis and sociology. By means of a case study of the collective identities of British trade unions in the 1980s and early 1990s, the article shows that despite a strong internationalist rhetoric, British unions responded to economic globalization and European integration during this period with a discourse of economic nationalism which also came to be strengthened and reinforced by strong feelings of shame and anger, which in turn undercut the articulation of broader forms of identification at either the European or the wider supra-national levels. Drawing on a theoretical framework developed in a previous article, the main argument is that in the context of an increasingly global economy and a hostile Conservative government, British unions' increasing economic nationalism may be thought of partly as discourse or political rhetoric and partly as a ‘social defence mechanism’ rooted in the anxiety generated by the social conditions of the unions. Finally, the data also lend some, albeit tentative, support to the thesis advanced by a number of authors that national identities and their accompanying emotions also tend to be expressed in a gendered form.
Stratified rights and the management of migration: National distinctiveness in Europe
Authors: Morris Lydia
Published: July 2002

This article offers a comparative study of rights and controls with respect to migration, based on research in Germany, Britain and Italy. These three countries were chosen both for their differing histories and for their contrasting contemporary circumstances, as a means of identifying the problems which confront any attempt at harmonization. The analysis offers an approach midway between an exaggerated view of national closure and control, and an over-emphasis on the power of transnational rights. Focusing instead on stratified rights or ‘civic stratification’, the article examines the different legal statuses available to non-EEA migrants, and identifies key contrasts in the management of migration in each of the three countries studied. It offers a tentative typology to capture these contrasts, and reflects on their significance for a harmonized Europe.
Structure, Subunit Topology, and Actin-binding Activity of the Arp2/3 Complex from Acanthamoeba
Authors: Mullins R. Dyche , Stafford Walter F. , Pollard Thomas D.
Published: July 2002

The Arp2/3 complex, first isolated from Acanthamoeba castellani by affinity chromatography on profilin, consists of seven polypeptides; two actinrelated proteins, Arp2 and Arp3; and five apparently novel proteins, p40, p35, p19, p18, and p14 (Machesky et al., 1994). The complex is homogeneous by hydrodynamic criteria with a Stokes' radius of 5.3 nm by gel filtration, sedimentation coefficient of 8.7 S, and molecular mass of 197 kD by analytical ultracentrifugation. The stoichiometry of the subunits is 1:1:1:1:1:1:1, indicating the purified complex contains one copy each of seven polypeptides. In electron micrographs, the complex has a bilobed or horseshoe shape with outer dimensions of ∼13 × 10 nm, and mathematical models of such a shape and size are consistent with the measured hydrodynamic properties. Chemical cross-linking with a battery of cross-linkers of different spacer arm lengths and chemical reactivities identify the following nearest neighbors within the complex: Arp2 and p40; Arp2 and p35; Arp3 and p35; Arp3 and either p18 or p19; and p19 and p14. By fluorescent antibody staining with anti-p40 and -p35, the complex is concentrated in the cortex of the ameba, especially in linear structures, possibly actin filament bundles, that lie perpendicular to the leading edge. Purified Arp2/3 complex binds actin filaments with a Kd of 2.3 μM and a stoichiometry of approximately one complex molecule per actin monomer. In electron micrographs of negatively stained samples, Arp2/3 complex decorates the sides of actin filaments. EDC/NHS cross-links actin to Arp3, p35, and a low molecular weight subunit, p19, p18, or p14. We propose structural and topological models for the Arp2/3 complex and suggest that affinity for actin filaments accounts for the localization of complex subunits to actinrich regions of Acanthamoeba.
L-Selectin from Human, but Not from Mouse Neutrophils Binds Directly to E-Selectin
Authors: Zöllner Olaf , Lenter Martin C. , Blanks James E. , Borges Eric , Steegmaier Martin , Zerwes Hans-Günther , Vestweber Dietmar
Published: July 2002

L-Selectin on neutrophils as well as inducible E- and P-selectin on endothelium are involved in the recruitment of neutrophils into inflamed tissue. Based on cell attachment assays, L-selectin was suggested to function as a carbohydrate presenting ligand for E- and P-selectin. However, previous affinity isolation experiments with an E-selectin–Ig fusion protein had failed to detect L-selectin among the isolated E-selectin ligands from mouse neutrophils. We show here that L-selectin from human neutrophils, in contrast to mouse neutrophils, can be affinity-isolated as a major ligand from total cell extracts using E-selectin–Ig as affinity probe. Binding of human L-selectin to E-selectin was direct, since purified L-selectin could be reprecipitated with E-selectin–Ig. Recognition of L-selectin was abolished by sialidase-treatment, required Ca2+, and was resistant to treatment with endoglycosidase F. Binding of L-selectin to a P-selectin–Ig fusion protein was not observed. In agreement with the biochemical data, the anti–Lselectin mAb DREG56 inhibited rolling of human neutrophils on immobilized E-selectin–Ig but not on P-selectin–Ig. No such inhibitory effect was seen with the anti–mouse L-selectin mAb MEL14 on mouse neutrophils. Rolling of E-selectin transfectants on purified and immobilized human L-selectin was inhibited by mAb DREG56. We conclude that L-selectin on human neutrophils is a major glycoprotein ligand among very few glycoproteins that can be isolated by an E-selectin affinity matrix. The clear difference between human and mouse L-selectin suggests that E-selectin–binding carbohydrate moieties are attached to different protein scaffolds in different species.
Integrin-mediated Activation of MAP Kinase Is Independent of FAK: Evidence for Dual Integrin Signaling Pathways in Fibroblasts
Authors: Lin Tsung H. , Aplin Andrew E. , Shen Yu , Chen Qiming , Schaller Michael , Romer Lewis , Aukhil Ikramuddin , Juliano R.L.
Published: July 2002

Integrin-mediated cell adhesion causes activation of MAP kinases and increased tyrosine phosphorylation of focal adhesion kinase (FAK). Autophosphorylation of FAK leads to the binding of SH2-domain proteins including Src-family kinases and the Grb2–Sos complex. Since Grb2–Sos is a key regulator of the Ras signal transduction pathway, one plausible hypothesis has been that integrin-mediated tyrosine phosphorylation of FAK leads to activation of the Ras cascade and ultimately to mitogen activated protein (MAP) kinase activation. Thus, in this scenario FAK would serve as an upstream regulator of MAP kinase activity. However, in this report we present several lines of evidence showing that integrin-mediated MAP kinase activity in fibroblasts is independent of FAK. First, a β1 integrin subunit deletion mutant affecting the putative FAK binding site supports activation of MAP kinase in adhering fibroblasts but not tyrosine phosphorylation of FAK. Second, fibroblast adhesion to bacterially expressed fragments of fibronectin demonstrates that robust activation of MAP kinase can precede tyrosine phosphorylation of FAK. Finally, we have used FRNK, the noncatalytic COOH-terminal domain of FAK, as a dominant negative inhibitor of FAK autophosphorylation and of tyrosine phosphorylation of focal contacts. Using retroviral infection, we demonstrate that levels of FRNK expression sufficient to completely block FAK tyrosine phosphorylation were without effect on integrin-mediated activation of MAP kinase. These results strongly suggest that integrin-mediated activation of MAP kinase is independent of FAK and indicate the probable existence of at least two distinct integrin signaling pathways in fibroblasts.