bluuebunny/crossref_metadata_2025 huggingface dataset:
Peer rejection in childhood, involvement with antisocial peers in early adolescence, and the
development of externalizing behavior problems
Authors: LAIRD ROBERT D. , JORDAN KRISTI Y. , DODGE KENNETH A. , PETTIT GREGORY S. , BATES JOHN E.
Published: October 2002

A longitudinal, prospective design was used to examine the roles of peer rejection in middle
childhood and antisocial peer involvement in early adolescence in the development of adolescent
externalizing behavior problems. Both early starter and late starter pathways were considered.
Classroom sociometric interviews from ages 6 through 9 years, adolescent reports of peers'
behavior at age 13 years, and parent, teacher, and adolescent self-reports of externalizing behavior
problems from age 5 through 14 years were available for 400 adolescents. Results indicate that
experiencing peer rejection in elementary school and greater involvement with antisocial peers in
early adolescence are correlated but that these peer relationship experiences may represent two
different pathways to adolescent externalizing behavior problems. Peer rejection experiences, but
not involvement with antisocial peers, predict later externalizing behavior problems when
controlling for stability in externalizing behavior. Externalizing problems were most common
when rejection was experienced repeatedly. Early externalizing problems did not appear to
moderate the relation between peer rejection and later problem behavior. Discussion highlights
multiple pathways connecting externalizing behavior problems from early childhood through
adolescence with peer relationship experiences in middle childhood and early adolescence.
Sound and urban life in a small Spanish town during the ancien régime
Authors: Marín Miguel Ángel
Published: October 2002

Although urban historians have recently begun to study the city and the senses, relatively few have investigated the aural environment experienced by the ear. To a certain extent, towns are thus characterized as silent societies and sounds of whatever kind are not viewed as an integral part of urban life. This article, based on a small Spanish town called Jaca, aims to describe some of its most notable sounds during the ancien régime and to explore how inhabitants perceived them. Such an approach provides a deeper and more comprehensive insight into the totality of the urban experience of townspeople of the period, and also suggests some new lines of enquiry for future musicological research.
Music and social class in Victorian London
Authors: Scott Derek B.
Published: October 2002

This essay looks at London in the second half of the nineteenth century, when features of musical life associated with a capitalist economy and the consolidation of power of a wealthy industrial bourgeoisie became firmly established. Prominent among such features, which are all closely related to the rapid increase in urban populations, were the commercialization and professionalization of music, new markets for cultural goods, a growing rift between art and entertainment, and the bourgeoisie's struggle for cultural domination.
Music in European cities and towns to c. 1650: a bibliographical survey
Authors: Kisby Fiona
Published: October 2002

As all urban historians will know, the 1996 Consolidated Bibliography of Urban History is one of the main resources for those researching the history of cities and towns in Europe and the rest of the world. Analysis of its c. 20,000 entries is revealing. Just over 50 per cent concern urban population, physical, social and economic structure and a further 12 per cent are devoted to transport and communications and politics and administration. Only around 6 per cent of the citations refer to urban ‘culture’ in any form and virtually none concern music in towns and cities in pre-industrial Europe or indeed that of any time or place. In the light of this, it is clear that urban history still tends to be restricted largely to the ‘essentially infrastructural’ and is still considered to be mostly ‘a matter of demography, distributive economics and consequential social arrangements and re-adjustments’.
Church music in English towns 1450–1550: an interim report
Authors: Barron Caroline M.
Published: October 2002

In the towns of late medieval England (where perhaps 10 per cent of the population may have lived) the parish churches were being continuously expanded, adapted and decorated. Chantry and fraternity chapels were added between the nave pillars, or at the eastern ends of the aisles and here, as well as at the high altar, masses were celebrated and prayers recited with incessant devotion by the living for the repose of the souls of those who had died. These intercessory services, together with those of the usual liturgical round which took place in the choir and in the nave, were increasingly accompanied by complex polyphonic music involving several singers, both men and boys, and the playing of organs which were becoming ubiquitous in medieval parish churches. The development of this dynamic parish music has been detected, but not much studied. In part this is the result of the failure of urban historians and musicologists to talk to each other. Historians of late medieval religion have recently been exploring the diversity and sophistication of parochial devotional practices and have reaffirmed the importance of religious guilds and chantry foundations in enriching the liturgical practices of the parish, but they have paid little attention to music, and none to the impact of church music on civic ceremonial and the legitimating processes of urban rulers. Musicologists who have worked on the music of the English church have been, until very recently, comparatively uninterested in what happened beyond the interior of the church and, in any case, more interested in the great royal and collegiate foundations from which some music has survived. The surprising conclusion is that, for both urban historians and musicologists, the connected argument that links religious ritual, broadly defined, with the spatial and social dimensions of life and work in towns barely yet exists.
Sounding the town
Authors: Borsay Peter
Published: October 2002

Interdisciplinarity has proved to be one of the enduring tenets of British urban history. As Fiona Kisby points out in her contribution to this special issue of Urban History, its centrality is enunciated in the agenda set by Jim Dyos in the 1960s, as the subject emerged as a self-conscious subdiscipline of British history, and in the editorials that launched this publication as a Yearbook and subsequently as a journal. The appeal of an interdisciplinary approach is that it allows those involved to transcend the straitjacket of traditional research and explore a given issue or subject from a multiplicity of angles. However, prioritizing such a methodology, though it might allow the intellectual high ground to be occupied temporarily, provides a real hostage to fortune, raising expectations that it often proves impossible to fulfil. Interdisciplinarity simply cuts against the dominant grain of academe. Where British urban historians have crossed the disciplinary barricades, they have tended to head in the direction of the social sciences (such as sociology, economics, geography and anthropology). A rapprochement with the arts (painting, film, literature, architecture, music, and the like) is less easy to discern. Yet with the growing interest in the last decade or so in cultural history the time is ripe to redress the balance. This music issue of Urban History, like that of August 1995 on ‘Art and the City’, can be seen as an attempt to do this. Its appearance coincides with the publication of a pioneering volume of essays, edited by Fiona Kisby, on Music and Musicians in Renaissance Cities and Towns, whose avowed aim is to ‘bring musicology within the sphere of urban history’. Though that collection is predominantly focused on western Europe (with six of the essays on the British Isles, six on the Continent, and one on South America) and on the years 1400 to 1650, it provides a model for how the agendas of musicologists and urban historians might be productively merged.
Molecular mechanisms of sulfasalazine‐induced T‐cell apoptosis
Authors: Liptay Susanne , Fulda Simone , Schanbacher Marta , Bourteele Soizic , Ferri Karine F , Kroemer Guido , Adler Guido , Debatin Klaus M , Schmid Roland M
Published: October 2002

Impaired apoptosis of T‐lymphocytes is involved in the development of chronic inflammatory disorders. Previously we have shown that the anti‐inflammatory drug sulfasalazine induces apoptosis in a murine T‐lymphocyte cell line. The aims of the present study were to expand these observations to human systems and to analyse the molecular basis for sulfasalazine‐induced apoptosis.

Sulfasalazine induces apoptosis both in Jurkat cells, a human T‐leukaemia cell line (ED50 value ∼1.0 mM), and in primary human peripheral blood T‐lymphocytes (ED50 value ∼0.5 mM). In contrast SW620 colon carcinoma cells or primary human synoviocytes are not affected at these concentrations suggesting a cell type‐specific sensitivity to sulfasalazine.

Sulfasalazine triggers the mitochondrial accumulation of Bax and induces a collapse of the mitochondrial transmembrane potential (ΔΨm).

Sulfasalazine causes cytochrome c release from mitochondria and subsequent activation of caspase‐3 and downstream substrates. However, the pan‐caspase inhibitor Z‐VAD.fmk fails to inhibit sulfasalazine‐induced apoptosis.

Sulfasalazine stimulates mitochondrio‐nuclear translocation of the novel apoptogenic factor apoptosis‐inducing factor (AIF) and triggers large‐scale DNA fragmentation, a characteristic feature of AIF‐mediated apoptosis.

Sulfasalazine‐induced ΔΨm loss, AIF redistribution, and cell death are fully prevented by overexpression of Bcl‐2.

In conclusion, our data suggest that sulfasalazine‐induced apoptosis of T‐lymphocytes is mediated by mitochondrio‐nuclear translocation of AIF and occurs in a caspase‐independent fashion. Sulfasalazine‐induced apoptosis by AIF and subsequent clearance of T‐lymphocytes might thus provide the molecular basis for the beneficial therapeutic effects of sulfasalazine in the treatment of chronic inflammatory diseases.

British Journal of Pharmacology (2002) 137, 608–620. doi:10.1038/sj.bjp.0704870
Extracellular zinc stimulates ERK‐dependent activation of p21Cip/WAF1 and inhibits proliferation of colorectal cancer cells
Authors: Park Ki‐Sook , Ahn Yongho , Kim Jin‐Ah , Yun Mi‐Sun , Seong Baik L , Choi Kang‐Yell
Published: October 2002

Zinc is an important trace element in the body and is involved in both the proliferation and growth arrest of many kinds of cells including colorectal epithelial cells. The aim of this study was to identify the molecular mechanism of the growth regulation of colorectal cancer cells by extracellular zinc.

Zinc‐stimulated activation of the mitogen‐activated protein kinase (MAPK) cascade was measured by immunoblotting and Elk‐1 dependent trans‐reporter gene expression, and zinc‐stimulated p21Cip/WAF1 activation by immunoblotting, Northern blot analysis and immunochemistry. Cell proliferation was measured by thymidine and bromodeoxyuridine (BrdU) incorporation.

By treating colorectal cancer cells with 100 μM ZnCl2, MAPKs were activated in two different phases, the initial weak activation occurred within 5 min and this was followed by a stronger and more prolonged activation.

Zinc concomitantly activated Raf‐1‐MEK‐MAPK kinases, and induced Elk‐1 dependent trans‐reporter gene expression.

Prolonged activation of MAPKs by 100 μM of ZnCl2 resulted in the induction and nuclear localization of p21Cip/WAF1 and was related to the inhibition of both thymidine and BrdU incorporations.

These results not only suggest the presence of a mechanism for p21Cip/WAF1 dependent negative regulation of colorectal cancer cell growth by zinc but also suggest potential usage of zinc to control the growth of colorectal cancer cells.

British Journal of Pharmacology (2002) 137, 597–607. doi:10.1038/sj.bjp.0704909
Involvement of tissue kallikrein but not plasma kallikrein in the development of symptoms mediated by endogenous kinins in acute pancreatitis in rats
Authors: Griesbacher Thomas , Rainer Irmgard , Tiran Beate , Evans D Michael
Published: October 2002

In order to investigate the mechanism of kinin release leading to vascular symptoms in acute interstitial‐oedematous pancreatitis, the novel, selective inhibitors of tissue kallikrein, (2S,2′R)‐2‐(2′‐amino‐3′‐(4′‐chlorophenyl)propanoylamino)‐N‐(3‐guanidinopropyl)‐3‐(1‐naphthyl)propanoamide (FE999024, CH‐2856), and of plasma kallikrein, (2′S,2′′R)‐4‐(2′‐(2′′(carboxymethylamino)‐3′′‐cyclohexyl‐propanoylamino)‐3′‐phenyl‐propanoylamino)piperidine‐1‐carboxamidin (FE999026, CH‐4215), were used in experimental caerulein‐induced pancreatitis in rats.

Oedema formation and plasma protein extravasation during the 2 h infusion of caerulein were inhibited in a dose‐dependent manner by i.p. pretreatment with FE999024 (7–60 μmol kg−1) while FE999026 had no effect at the same doses.

Haemoconcentration and hypovolaemia associated with the pancreatic oedema formation during pancreatitis were significantly attenuated by FE999024 at a dose of 20 μmol kg−1. The reduction in circulating plasma volume was not affected by FE999026.

Accumulation of amylase and lipase in the pancreas was dose‐dependently reduced by FE999024 while enzyme activities in the blood serum were increased by FE999024 at 60 μmol kg−1 indicating improved enzyme removal from the tissue. Enzyme activities in the tissue and in the blood remained unaffected by FE999026.

FE999024 (20 μmol kg−1) largely inhibited increased tissue kallikrein‐like activity in the pancreas during acute pancreatitis and also strongly attenuated influx of plasma kallikrein into the tissue. FE999026 (20 μmol kg−1) significantly inhibited plasma kallikrein‐like activity in the pancreas but had no effect on tissue kallikrein‐like activity.

In conclusion, vascular kinin‐mediated symptoms observed during oedematous pancreatitis in the rat are caused by the action of tissue kallikrein in the pancreas whereas an involvement of plasma kallikrein seems to be unlikely.

British Journal of Pharmacology (2002) 137, 692–700. doi:10.1038/sj.bjp.0704910
Role of the platelet‐activating factor (PAF) receptor during pulmonary infection with gram negative bacteria
Authors: Soares A C , Pinho V S , Souza D G , Shimizu T , Ishii S , Nicoli J R , Teixeira M M
Published: October 2002

The lipid mediator PAF plays an important role in the phagocytosis of particles, including bacteria, and consequent production of pro‐inflammatory cytokines, such as TNF‐α and IL‐8.

Using a PAF receptor antagonist (UK‐74,505) and PAF receptor knock‐out mice, we have investigated the relevance of PAF for the inflammatory changes and lethality after pulmonary infection with the gram‐negative bacteria Klebsiella pneumoniae in mice.

At an inoculum of 3×106 bacteria, there was marked pulmonary (bronchoalveolar lavage and lung) neutrophilia that started early (2.5 h after infection) and peaked at 48 h. All animals were dead by day 4 of infection. The chemokine KC and the pro‐inflammatory cytokine TNF‐α increased rapidly and persisted for 48 h in the lungs.

Pretreatment with UK‐74,505 (30 mg kg−1 per day, p.o.) had no significant effects on the number of infiltrating neutrophils in BAL fluid or lung tissue, as assessed by histology and measuring myeloperoxidase, or on the concentrations of KC. In contrast, concentrations of TNF‐α and the number of bacteria inside neutrophils were significantly diminished.

In order to support a role for the PAF during K. pneumoniae infection, experiments were also carried out in PAFR‐deficient mice. In the latter animals, lethality occurred earlier than in wild‐type controls. This was associated with greater number of bacteria in lung tissue and diminished percentage of neutrophils containing bacteria in their cytoplasm.

Our results suggest that PAF, acting on its receptor, plays a protective role during infection with K. pneumoniae in mice.

British Journal of Pharmacology (2002) 137, 621–628. doi:10.1038/sj.bjp.0704918
Inotropic responses to human gene 2 (B29) relaxin in a rat model of myocardial infarction (MI): effect of pertussis toxin
Authors: Kompa Andrew R , Samuel Chrishan S , Summers Roger J
Published: October 2002

Relaxin produces powerful inotropic and chronotropic responses in isolated atria. The effect of relaxin has been examined in a rat model of cardiac failure, induced by myocardial infarction (MI).

Maximum inotropic responses to isoprenaline (sham 5.4±0.3 mN; MI 2.6±0.3 mN; P<0.001) and relaxin (sham 5.1±0.6 mN; MI 2.8±0.5 mN; P=0.013) were reduced in left atria following MI. No change in chronotropic responsiveness was observed in right atria.

Pertussis toxin (PTX) treatment restored inotropic responses to isoprenaline (sham 5.5±1.3 mN; MI 5.8±1.0 mN; P=0.850) but not to relaxin. Instead, PTX reduced inotropic responses to relaxin in sham animals to the same level seen in the MI group (sham 3.2±1.7 mN; MI 2.8±0.6 mN; P=0.847). In right atria, PTX treatment did not affect the maximum chronotropic response to isoprenaline, but reduced responses to relaxin in both sham and MI animals.

R3 relaxin and relaxin receptor (LGR7) mRNA was present in atria and left ventricle (LV) from sham and MI animals. R3 relaxin mRNA expression was increased in atria but not LV from MI animals. LGR7 mRNA expression was reduced in atria and LV from MI animals.

PTX treatment in unoperated rats increased chronotropic responses (vehicle 184.3±5.3 beats min−1; PTX 211.3±9.5 beats min−1; P=0.029) and produced a rightward shift in the concentration‐response curve to isoprenaline in left atria. PTX reduced inotropic (vehicle 3.3±0.7 mN; PTX 0.8±0.2 mN; P=0.005) and chronotropic (vehicle 130.2±8.1 beats min−1; PTX 90.6±11.1 beats min−1; P=0.012) responses to relaxin.

In left atria, relaxin produced a small increase in cAMP compared to those produced by isoprenaline and forskolin. However, PTX treatment significantly reduced relaxin‐, isoprenaline‐ and forskolin‐stimulated cAMP accumulation.

Cardiac failure in MI animals caused a reduced inotropic response to both relaxin and (−)‐isoprenaline. In non‐MI animals, PTX treatment also reduced inotropic responses to relaxin. Differences between responses to (−)‐isoprenaline and relaxin can be explained by changes in coupling efficiency occurring at the level of adenylate cyclase.

British Journal of Pharmacology (2002) 137, 710–718. doi:10.1038/sj.bjp.0704922
Evolution of moth sex pheromones via ancestral genes
Authors: Roelofs Wendell L. , Liu Weitian , Hao Guixia , Jiao Hongmei , Rooney Alejandro P. , Linn Charles E.
Published: October 2002

Mate finding in most moth species involves long-distance signaling via female-emitted sex pheromones. There is a great diversity of pheromone structures used throughout the Lepidoptera, even among closely related species. The conundrum is how signal divergence has occurred. With strong normalizing selection pressure on blend composition and response preferences, it is improbable that shifts to pheromones of diverse structures occur through adaptive changes in small steps. Here, we present data supporting the hypothesis that a major shift in the pheromone of anOstriniaspecies occurred by activation of a nonfunctional desaturase gene transcript present in the pheromone gland. We also demonstrate the existence of rare males that respond to the new pheromone blend. Their presence would allow for asymmetric tracking of male response to the new blend and, thus, evolution of anOstriniaspecies with structurally different sex pheromone components.
COX-3, a cyclooxygenase-1 variant inhibited by acetaminophen and other analgesic/antipyretic drugs: Cloning, structure, and expression
Authors: Chandrasekharan N. V. , Dai Hu , Roos K. Lamar Turepu , Evanson Nathan K. , Tomsik Joshua , Elton Terry S. , Simmons Daniel L.
Published: October 2002

Two cyclooxygenase isozymes, COX-1 and -2, are known to catalyze the rate-limiting step of prostaglandin synthesis and are the targets of nonsteroidal antiinflammatory drugs. Here we describe a third distinct COX isozyme, COX-3, as well as two smaller COX-1-derived proteins (
p
artial
COX-1
or PCOX-1 proteins). COX-3 and one of the PCOX-1 proteins (PCOX-1a) are made from the COX-1 gene but retain intron 1 in their mRNAs. PCOX-1 proteins additionally contain an in-frame deletion of exons 5–8 of the COX-1 mRNA. COX-3 and PCOX mRNAs are expressed in canine cerebral cortex and in lesser amounts in other tissues analyzed. In human, COX-3 mRNA is expressed as an ≈5.2-kb transcript and is most abundant in cerebral cortex and heart. Intron 1 is conserved in length and in sequence in mammalian COX-1 genes. This intron contains an ORF that introduces an insertion of 30–34 aa, depending on the mammalian species, into the hydrophobic signal peptide that directs COX-1 into the lumen of the endoplasmic reticulum and nuclear envelope. COX-3 and PCOX-1a are expressed efficiently in insect cells as membrane-bound proteins. The signal peptide is not cleaved from either protein and both proteins are glycosylated. COX-3, but not PCOX-1a, possesses glycosylation-dependent cyclooxygenase activity. Comparison of canine COX-3 activity with murine COX-1 and -2 demonstrates that this enzyme is selectively inhibited by analgesic/antipyretic drugs such as acetaminophen, phenacetin, antipyrine, and dipyrone, and is potently inhibited by some nonsteroidal antiinflammatory drugs. Thus, inhibition of COX-3 could represent a primary central mechanism by which these drugs decrease pain and possibly fever.
APC-dependent suppression of colon carcinogenesis by PPARγ
Authors: Girnun Geoffrey D. , Smith Wendy M. , Drori Stavit , Sarraf Pasha , Mueller Elisabetta , Eng Charis , Nambiar Prashant , Rosenberg Daniel W. , Bronson Roderick T. , Edelmann Winfried , Kucherlapati Raju , Gonzalez Frank J. , Spiegelman Bruce M.
Published: October 2002

Activation of PPARγ by synthetic ligands, such as thiazolidinediones, stimulates adipogenesis and improves insulin sensitivity. Although thiazolidinediones represent a major therapy for type 2 diabetes, conflicting studies showing that these agents can increase or decrease colonic tumors in mice have raised concerns about the role of PPARγ in colon cancer. To analyze critically the role of this receptor, we have used mice heterozygous for
Ppar
γ with both chemical and genetic models of this malignancy. Heterozygous loss of PPARγ causes an increase in β-catenin levels and a greater incidence of colon cancer when animals are treated with azoxymethane. However, mice with preexisting damage to
Apc
, a regulator of β-catenin, develop tumors in a manner insensitive to the status of PPARγ. These data show that PPARγ can suppress β-catenin levels and colon carcinogenesis but only before damage to the APC/β-catenin pathway. This finding suggests a potentially important use for PPARγ ligands as chemopreventative agents in colon cancer.
Divergence between samples of chimpanzee and human DNA sequences is 5%, counting indels
Authors: Britten Roy J.
Published: October 2002

Five chimpanzee bacterial artificial chromosome (BAC) sequences (described in GenBank) have been compared with the best matching regions of the human genome sequence to assay the amount and kind of DNA divergence. The conclusion is the old saw that we share 98.5% of our DNA sequence with chimpanzee is probably in error. For this sample, a better estimate would be that 95% of the base pairs are exactly shared between chimpanzee and human DNA. In this sample of 779 kb, the divergence due to base substitution is 1.4%, and there is an additional 3.4% difference due to the presence of indels. The gaps in alignment are present in about equal amounts in the chimp and human sequences. They occur equally in repeated and nonrepeated sequences, as detected by
repeatmasker
(
http://ftp.genome.washington.edu/RM/RepeatMasker.html
).
Liver X receptors in the central nervous system: From lipid homeostasis to neuronal degeneration
Authors: Wang Ling , Schuster Gertrud U. , Hultenby Kjell , Zhang Qinghong , Andersson Sandra , Gustafsson Jan-Åke
Published: October 2002

Liver X receptors (LXRα and -β) are nuclear receptors abundant in the liver where they are regulators of lipid homeostasis. Both LXRs are also expressed in the brain, but their roles in this tissue remain to be clarified. We examined the brains of mice in which the genes of both LXRα and -β have been disrupted and found several severe abnormalities. One of the most striking features is that the lateral ventricles are closed and lined with lipid-laden cells. In addition, there are enlarged brain blood vessels, especially in the pars reticularis of the substantia nigra and in the globus pallidus. Other features of the brains are excessive lipid deposits, proliferation of astrocytes, loss of neurons, and disorganized myelin sheaths. Electron micrographs revealed that, as mice aged, lipid vacuoles accumulated in astrocytes surrounding blood vessels. Comparison of mRNA profiles in LXR knockout mice and wild-type littermates showed that expression of several LXR target genes involved in cholesterol efflux from astrocytes was reduced. These findings show that LXRs have an important function in lipid homeostasis in the brain, and that loss of these receptors results in neurodegenerative diseases. Further characterization of the role of LXRs in the brain could lead to new insights into the etiology and treatment of some neurodegenerative disorders.
Histone deacetylase 6 binds polyubiquitin through its zinc finger (PAZ domain) and copurifies with deubiquitinating enzymes
Authors: Hook Sara S. , Orian Amir , Cowley Shaun M. , Eisenman Robert N.
Published: October 2002

Histone deacetylases (HDACs) are thought to function as critical mediators of transcriptional repression. However, the physiological targets and posttranslational modifications of the class II HDACs are largely unknown. Here we show that the C terminus of HDAC 6 is both necessary and sufficient for specific association with polyubiquitin. This region contains a putative zinc finger but lacks significant similarity to other known ubiquitin binding domains. Thus, we have designated this region as a PAZ domain, for
P
olyubiquitin
A
ssociated
Z
inc finger. Although the PAZ domain possesses homology with the zinc finger of deubiquitinating enzymes, it is dispensable for the deubiquitinating activity we find associated with HDAC6 following immunopurification. We also show that both HDAC 5 and HDAC 6 are ubiquitinated
in vitro
and
in vivo
. However, both of these proteins are stable
in vivo
and do not appear to be targeted for rapid degradation by the proteasome. Thus, HDAC6 is linked to the ubiquitin system via ubiquitin conjugation, polyubiquitin binding, and copurification with deubiquitinating enzymes.
Depletion of neutrophils blocks the recruitment of antigen-nonspecific cells into the liver without affecting the antiviral activity of hepatitis B virus-specific cytotoxic T lymphocytes
Authors: Sitia Giovanni , Isogawa Masanori , Kakimi Kazuhiro , Wieland Stefan F. , Chisari Francis V. , Guidotti Luca G.
Published: October 2002

Using transgenic mice that replicate hepatitis B virus (HBV) in their livers, we previously showed that passively transferred HBV-specific cytotoxic T cells (CTLs) recruit antigen-nonspecific lymphomononuclear and polymorphonuclear inflammatory cells that contribute to the pathogenesis of liver disease. This process is chemokine-dependent, because we recently showed that blocking the chemokines CXCL9 and CXCL10 reduces the recruitment of antigen-nonspecific lymphomononuclear cells and the severity of liver disease after CTL injection. In the current study we show that the severity of the CTL-initiated liver disease is also ameliorated by the depletion of neutrophils. Interestingly, depletion of neutrophils does not affect the intrahepatic migration or antiviral activity of CTLs, but it profoundly inhibits the recruitment of all antigen-nonspecific cells into the liver. This effect occurs in face of high intrahepatic levels of chemokine gene expression, suggesting that neutrophil-dependent functions other than chemokine induction are necessary for the recruitment process to occur. The notion that depletion of neutrophils is associated with maintenance of antiviral effects but diminished tissue damage may be significant for the development of immunotherapeutic approaches for the treatment of chronic HBV infection.
Bystander effect produced by radiolabeled tumor cells
in
vivo
Authors: Xue Lanny Y. , Butler Nicholas J. , Makrigiorgos G. Mike , Adelstein S. James , Kassis Amin I.
Published: October 2002

The bystander effect, originating from cells irradiated
in vitro
, describes the biologic response(s) of surrounding cells not directly targeted by a radiation insult. To overcome the limitations of
in vitro
tissue culture models and determine whether a bystander effect that is initiated by the
in vivo
decay of a radionuclide can be demonstrated in an animal, the ability of 5-[
125
I]iodo-2′-deoxyuridine (
125
IUdR)-labeled tumor cells to exert a damaging effect on neighboring unlabeled tumor cells growing s.c. in nude mice has been investigated. When mice are injected with a mixture of human colon LS174T adenocarcinoma cells and LS174T cells prelabeled with lethal doses of DNA-incorporated
125
I, a distinct inhibitory effect on the growth of s.c. tumor (derived from unlabeled cells) is observed. Because (
i
) the
125
I present within the cells is DNA-bound, (
ii
) ≈99% of the electrons emitted by the decaying
125
I atoms have a subcellular range (<0.5 μm), and (
iii
) the overall radiation dose deposited by radiolabeled cells in the unlabeled cells within the growing tumor is <10 cGy, we conclude that the results obtained are a consequence of a bystander effect that is generated
in vivo
by factor(s) present within and/or released from the
125
IUdR-labeled cells. These
in vivo
findings significantly impact the current dogma for assessing the therapeutic potential of internally administered radionuclides. They also call for reevaluation of the approaches currently used for estimating the risks to individuals and populations inadvertently exposed internally to radioactivity as well as to patients undergoing routine diagnostic nuclear medical procedures.
Activity patterns in human motion-sensitive areas depend on the interpretation of global motion
Authors: Castelo-Branco Miguel , Formisano Elia , Backes Walter , Zanella Friedhelm , Neuenschwander Sergio , Singer Wolf , Goebel Rainer
Published: October 2002

Numerous imaging studies have contributed to the localization of motion-sensitive areas in the human brain. It is, however, still unclear how these areas contribute to global motion perception. Here, we investigate with functional MRI whether the motion-sensitive area hMT
+
/V5 is involved in perceptual segmentation and integration of motion signals. Stimuli were overlapping moving gratings that can be perceived either as two independently moving, transparent surfaces or as a single surface moving in an intermediate direction. We examined whether motion-sensitive area hMT
+
/V5 is involved in mediating the switches between the two percepts. The data show differential activation of hMT
+
/V5 with perceptual switches, suggesting that these are associated with a reconfiguration of cell assemblies in this area.
Helix–hairpin–helix motifs confer salt resistance and processivity on chimeric DNA polymerases
Authors: Pavlov Andrey R. , Belova Galina I. , Kozyavkin Sergei A. , Slesarev Alexei I.
Published: October 2002

Helix–hairpin–helix (HhH) is a widespread motif involved in sequence-nonspecific DNA binding. The majority of HhH motifs function as DNA-binding modules with typical occurrence of one HhH motif or one or two (HhH)
2
domains in proteins. We recently identified 24 HhH motifs in DNA topoisomerase V (Topo V). Although these motifs are dispensable for the topoisomerase activity of Topo V, their removal narrows the salt concentration range for topoisomerase activity tenfold. Here, we demonstrate the utility of Topo V's HhH motifs for modulating DNA-binding properties of the Stoffel fragment of
Taq
DNA polymerase and
Pfu
DNA polymerase. Different HhH cassettes fused with either NH
2
terminus or COOH terminus of DNA polymerases broaden the salt concentration range of the polymerase activity significantly (up to 0.5 M NaCl or 1.8 M potassium glutamate). We found that anions play a major role in the inhibition of DNA polymerase activity. The resistance of initial extension rates and the processivity of chimeric polymerases to salts depend on the structure of added HhH motifs. Regardless of the type of the construct, the thermal stability of chimeric
Taq
polymerases increases under the optimal ionic conditions, as compared with that of
Taq
DNA polymerase or its Stoffel fragment. Our approach to raise the salt tolerance, processivity, and thermostability of
Taq
and
Pfu
DNA polymerases may be applied to all pol1- and polB-type polymerases, as well as to other DNA processing enzymes.
Hydrodynamic injection of viral DNA: A mouse model of acute hepatitis B virus infection
Authors: Yang Priscilla L. , Althage Alana , Chung Josan , Chisari Francis V.
Published: October 2002

Hepatitis B virus (HBV) is a prototype for liver-specific pathogens in which the failure of the immune system to mount an effective response leads to chronic infection. Our understanding of the immune response to HBV is incomplete, largely due to the narrow host restriction of this pathogen and the limitations of existing experimental models. We have developed a murine model for studying human HBV replication, immunogenicity, and control. After transfection of hepatocytesin vivowith a replication-competent, over-length, linear HBV genome, viral antigens and replicative intermediates were synthesized and virus was secreted into the blood. Viral antigens disappeared from the blood as early as 7 days after transfection, coincident with the appearance of antiviral antibodies. HBV transcripts and replicative intermediates disappeared from the liver by day 15, after the appearance of antiviral CD8 + T cells. In contrast, the virus persisted for at least 81 days after transfection of NOD/Scid mice, which lack functional T cells, B cells, and natural killer (NK) cells. Thus, the outcome of hydrodynamic transfection of HBV depends on the host immune response, as it is during a natural infection. The methods we describe will allow the examination of viral dynamics in a tightly controlledin vivosystem, the application of mutagenesis methods to the study of the HBV life cyclein vivo, and the dissection of the immune response to HBV using genetically modified mice whose immunoregulatory and immune effector functions have been deleted or overexpressed. In addition, this methodology represents a prototype for the study of other known and to-be-discovered liver-specific pathogens.
Natural radioactivity and human mitochondrial DNA mutations
Authors: Forster Lucy , Forster Peter , Lutz-Bonengel Sabine , Willkomm Horst , Brinkmann Bernd
Published: October 2002

Radioactivity is known to induce tumors, chromosome lesions, and minisatellite length mutations, but its effects on the DNA sequence have not previously been studied. A coastal peninsula in Kerala (India) contains the world's highest level of natural radioactivity in a densely populated area, offering an opportunity to characterize radiation-associated DNA mutations. We sampled 248 pedigrees (988 individuals) in the high-radiation peninsula and in nearby low-radiation islands as a control population. We sequenced their mtDNA, and found that the pedigrees living in the high-radiation area have significantly (
P
< 0.01) increased germ-line point mutations between mothers and their offspring. In each mutation case, we confirmed maternity by autosomal profiling. Strikingly, the radioactive conditions accelerate mutations at nucleotide positions that have been evolutionary hot spots for at least 60,000 years.
On the power of chemical synthesis: Immunological evaluation of models for multiantigenic carbohydrate-based cancer vaccines
Authors: Ragupathi Govindaswami , Coltart Don M. , Williams Lawrence J. , Koide Fusataka , Kagan Ella , Allen Jennifer , Harris Christina , Glunz Peter W. , Livingston Philip O. , Danishefsky Samuel J.
Published: October 2002

Synthetic carbohydrate cancer vaccines have been shown to stimulate antibody-based immune responses in both preclinical and clinical settings. The antibodies have been observed to reactin vitrowith the corresponding natural carbohydrate antigens expressed on the surface of tumor cells, and are able to mediate complement-dependent and/or antibody-dependent cell-mediated cytotoxicity. Furthermore, these vaccines have proven to be safe when administered to cancer patients. Until recently, only monovalent antigen constructs had been prepared and evaluated. Advances in total synthesis have now enabled the preparation of multivalent vaccine constructs, which contain several different tumor-associated carbohydrate antigens. Such constructs could, in principle, serve as superior mimics of cell surface antigens and, hence, as potent cancer vaccines. Here we report preclinical ELISA-based evaluation of a TF–Ley–Tn bearing construct (compound 3) with native mucin glycopeptide architecture and a Globo-H–Ley–Tn glycopeptide (compound 4) with a nonnative structure. Mice were immunized with one or the other of these constructs as free glycopeptides or as keyhole lymphet hemocyanin conjugates. Either QS-21 or the related GPI-0100 were coadministered as adjuvants. Both keyhole lymphet hemocyanin conjugates induced IgM and IgG antibodies against each carbohydrate antigen, however, the mucin-based TF–Ley–Tn construct was shown to be less antigenic than the unnatural Globo-H–Ley–Tn construct. The adjuvants, although related, proved significantly different, in that GPI-0100 consistently induced higher titers of antibodies than QS-21. The presence of multiple glycans in these constructs did not appear to suppress the response against any of the constituent antigens. Compound 4, the more antigenic of the two constructs, was also examined by fluorescence activated cell sorter analysis. Significantly, from these studies it was shown that antibodies stimulated in response to compound 4 reacted with tumor cells known to selectively express the individual antigens. The results demonstrate that single vaccine constructs bearing several different carbohydrate antigens have the potential to stimulate a multifaceted immune response.
The Ume6 regulon coordinates metabolic and meiotic gene expression in yeast
Authors: Williams Roy M. , Primig Michael , Washburn Brian K. , Winzeler Elizabeth A. , Bellis Michel , Sarrauste de Menthière Cyril , Davis Ronald W. , Esposito Rochelle E.
Published: October 2002

The Ume6 transcription factor in yeast is known to both repress and activate expression of diverse genes during growth and meiotic development. To obtain a more complete profile of the functions regulated by this protein, microarray analysis was used to examine transcription in wild-type and
ume6
Δ diploids during vegetative growth in glucose and acetate. Two different genetic backgrounds (W303 and SK1) were examined to identify a core set of strain-independent Ume6-regulated genes. Among genes whose expression is controlled by Ume6 in both backgrounds, 82 contain homologies to the Ume6-binding site (URS1) and are expected to be directly regulated by Ume6. The vast majority of those whose functions are known participate in carbon/nitrogen metabolism and/or meiosis. Approximately half of the Ume6 direct targets are induced during meiosis, with most falling into the early meiotic expression class (cluster 4), and a smaller subset in the middle and later classes (clusters 5–7). Based on these data, we propose that Ume6 serves a unique role in diploid cells, coupling metabolic responses to nutritional cues with the initiation and progression of meiosis. Finally, expression patterns in the two genetic backgrounds suggest that SK1 is better adapted to respiration and W303 to fermentation, which may in part account for the more efficient and synchronous sporulation of SK1.
Functional evidence for the mediation of diabetogenic T cell responses by HLA-A2.1 MHC class I molecules through transgenic expression in NOD mice
Authors: Marron Michele P. , Graser Robert T. , Chapman Harold D. , Serreze David V.
Published: October 2002

Particular major histocompatibility complex (MHC) class II alleles clearly contribute to T cell-mediated autoimmune type 1 diabetes (T1D) in both humans and nonobese diabetic (NOD) mice. However, studies in NOD mice indicate MHC class I-restricted T cell responses are also essential to T1D development. In humans, epidemiological studies have suggested that some common class I alleles, including HLA-A2.1 (A*02011), may confer increased susceptibility to T1D when expressed in conjunction with certain class II alleles. We show here that when HLA-A2.1 molecules are transgenically expressed in NOD mice, A2-restricted T cell responses arise against pancreatic β cells, leading to an earlier onset of T1D. The accelerated onset of T1D in the NOD.HLA-A2.1transgenic mice is not due to nonspecific effects of expressing a third class I molecule, because a stock of NOD mice transgenically expressing HLA-B27 class I molecules showed no such acceleration of T1D, but rather were significantly protected from disease. These findings provide the first functional evidence that certain human MHC class I molecules can contribute to the development of T1D.
Molecular evidence for ecological speciation in tropical habitats
Authors: Ogden Rob , Thorpe Roger S.
Published: October 2002

Recent research on rainforest speciation has highlighted the importance of habitat variation in generating population diversification but lacks evidence of an associated reduction in gene flow. This paper describes a study in which molecular markers were used to examine the effects of allopatric divergence and habitat on levels of gene flow in the Caribbean lizard,
Anolis roquet
. Three study transects were constructed to compare variation in microsatellite allele frequencies and morphology across phylogenetic and habitat boundaries in northern Martinique. Results showed reductions in gene flow to be concordant with divergent selection for habitat type. No evidence could be found for divergence in allopatry influencing current gene flow. Morphological data match these findings, with multivariate analysis showing correlation with habitat type but no grouping by phylogenetic lineage. The results support the ecological speciation model of evolutionary divergence, indicating the importance of habitats in biodiversity generation.
Linkage limits the power of natural selection in
Drosophila
Authors: Betancourt Andrea J. , Presgraves Daven C.
Published: October 2002

Population genetic theory shows that the efficacy of natural selection is limited by linkage—selection at one site interferes with selection at linked sites. Such interference slows adaptation in asexual genomes and may explain the evolutionary advantage of sex. Here, we test for two signatures of constraint caused by linkage in a sexual genome, by using sequence data from 255
Drosophila melanogaster
and
Drosophila simulans
loci. We find that (
i
) the rate of protein adaptation is reduced in regions of low recombination, and (
ii
) evolution at strongly selected amino acid sites interferes with optimal codon usage at weakly selected, tightly linked synonymous sites. Together these findings suggest that linkage limits the rate and degree of adaptation even in recombining genomes.
Microarray analysis identifies
Salmonella
genes belonging to the low-shear modeled microgravity regulon
Authors: Wilson James W. , Ramamurthy Rajee , Porwollik Steffen , McClelland Michael , Hammond Timothy , Allen Pat , Ott C. Mark , Pierson Duane L. , Nickerson Cheryl A.
Published: October 2002

The low-shear environment of optimized rotation suspension culture allows both eukaryotic and prokaryotic cells to assume physiologically relevant phenotypes that have led to significant advances in fundamental investigations of medical and biological importance. This culture environment has also been used to model microgravity for ground-based studies regarding the impact of space flight on eukaryotic and prokaryotic physiology. We have previously demonstrated that low-shear modeled microgravity (LSMMG) under optimized rotation suspension culture is a novel environmental signal that regulates the virulence, stress resistance, and protein expression levels of
Salmonella enterica
serovar Typhimurium. However, the mechanisms used by the cells of any species, including
Salmonella
, to sense and respond to LSMMG and identities of the genes involved are unknown. In this study, we used DNA microarrays to elucidate the global transcriptional response of
Salmonella
to LSMMG. When compared with identical growth conditions under normal gravity (1 ×
g
), LSMMG differentially regulated the expression of 163 genes distributed throughout the chromosome, representing functionally diverse groups including transcriptional regulators, virulence factors, lipopolysaccharide biosynthetic enzymes, iron-utilization enzymes, and proteins of unknown function. Many of the LSMMG-regulated genes were organized in clusters or operons. The microarray results were further validated by RT-PCR and phenotypic analyses, and they indicate that the ferric uptake regulator is involved in the LSMMG response. The results provide important insight about the
Salmonella
LSMMG response and could provide clues for the functioning of known
Salmonella
virulence systems or the identification of uncharacterized bacterial virulence strategies.
The origin of a developmentally regulatedIghreplicon is located near the border of regulatory domains forIghreplication and expression
Authors: Zhou Jie , Ashouian Nasrin , Delepine Marc , Matsuda Fumihiko , Chevillard Christophe , Riblet Roy , Schildkraut Carl L. , Birshtein Barbara K.
Published: October 2002

The 3′ Ig heavy chain locus (Igh) regulatory region is the most downstream known element of the murineIghgene cluster. We report here that the nearest non-Ighgenes—Crip,Crp2, andMta1—are located ≈70 kb further downstream and are beyond the end of the domain ofIghtranscriptional regulation. We have localized an origin of replication in MEL cells to a 3-kb segment located between the 3′Ighregulatory region andCrip. Sequences downstream of this origin are replicated by forks that move in both directions. Sequences upstream of this origin (Igh-C,-D, and -J) are replicated in a single direction through a 500-kb segment in which no active bidirectional origins can be detected. We propose that this origin may lie at or near the end of theIghregulation domain.
Structure of the single-strand annealing domain of human RAD52 protein
Authors: Singleton Martin R. , Wentzell Lois M. , Liu Yilun , West Stephen C. , Wigley Dale B.
Published: October 2002

In eukaryotic cells, RAD52 protein plays a central role in genetic recombination and DNA repair by (
i
) promoting the annealing of complementary single-stranded DNA and (
ii
) stimulation of the RAD51 recombinase. The single-strand annealing domain resides in the N-terminal region of the protein and is highly conserved, whereas the nonconserved RAD51-interaction domain is located in the C-terminal region. An N-terminal fragment of human RAD52 (residues 1–209) has been purified to homogeneity and, similar to the full-size protein (residues 1–418), shown to promote single-strand annealing
in vitro
. We have determined the crystal structure of this single-strand annealing domain at 2.7 Å. The structure reveals an undecameric (11) subunit ring with extensive subunit contacts. A large, positively charged groove runs along the surface of the ring, readily suggesting a mechanism by which RAD52 presents the single strand for reannealing with complementary single-stranded DNA.