bluuebunny/crossref_metadata_2025 huggingface dataset:
G
1
cell cycle arrest and apoptosis induction by nuclear Smad4/Dpc4: Phenotypes reversed by a tumorigenic mutation
Authors: Dai Jia Le , Bansal Ravi K. , Kern Scott E.
Published: July 2002

The tumor suppressor Smad4/Dpc4 is a transcription activator that
binds specific DNA sequences and whose nuclear localization is induced
after exposure to type β transforming growth factor-like cytokines.
We explored an inducible system in which Smad4 protein is activated by
translocation to the nucleus when cell lines that stably express
wild-type or mutant Smad4 proteins fused to a murine estrogen receptor
domain are treated with 4-hydroxytamoxifen. This induced Smad4-mediated
transcriptional activation and a decrease in growth rate, attributable
to a cell cycle arrest at the G
1
phase and an induction of
apoptosis. A tumor-derived mutation (Arg-100 → Thr)
affecting a residue critical for DNA-binding demonstrated an
“oncogenic” phenotype, having decreases in both the
G
1
fraction and apoptosis and, consequently, an
augmentation of population growth. This model should be useful in the
exploration and control of components that lie further downstream in
the Smad4 tumor-suppressor pathway.
GroES in the asymmetric GroEL
14
–GroES
7
complex exchanges via an associative mechanism
Authors: Horowitz Paul M. , Lorimer George H. , Ybarra Jesse
Published: July 2002

The interaction of the chaperonin GroEL
14
with its cochaperonin GroES
7
is dynamic, involving stable, asymmetric 1:1 complexes (GroES
7
⋅GroEL
7
–GroEL
7
) and transient, metastable symmetric 2:1 complexes [GroES
7
⋅GroEL
7
–GroEL
7
⋅GroES
7
]. The transient formation of a 2:1 complex permits exchange of free GroES
7
for GroES
7
bound in the stable 1:1 complex. Electrophoresis in the presence of ADP was used to resolve free GroEL
14
from the GroES
7
–GroEL
14
complex. Titration of GroEL
14
with radiolabeled GroES
7
to molar ratios of 32:1 demonstrated a 1:1 limiting stoichiometry in a stable complex. No stable 2:1 complex was detected. Preincubation of the asymmetric GroES
7
⋅GroEL
7
–GroEL
7
complex with excess unlabeled GroES
7
in the presence of ADP demonstrated GroES
7
exchange. The rates of GroES
7
exchange were proportional to the concentration of unlabeled free GroES
7
. This concentration dependence points to an associative mechanism in which exchange of GroES
7
occurs by way of a transient 2:1 complex and excludes a dissociative mechanism in which exchange occurs by way of free GroEL
14
. Exchange of radiolabeled ADP from 1:1 complexes was much slower than the exchange of GroES
7
. In agreement with recent structural studies, this indicates that conformational changes in GroEL
14
following the dissociation of GroES
7
must precede ADP release. These results explain how the GroEL
14
cavity can become reversibly accessible to proteins under
in vivo
conditions that favor 2:1 complexes.
Overexpression of
Xenopus
laevis
growth hormone stimulates growth of tadpoles and frogs
Authors: Huang Haochu , Brown Donald D.
Published: July 2002

The role of growth hormone (GH) in amphibian metamorphosis is ambiguous based on experiments in which mammalian GH was administered to tadpoles and frogs. We have reexamined the effects of GH by producing transgenic
Xenopus laevis
that overexpress the cDNA encoding
X. laevis
GH. These transgenic tadpoles take the same length of time to reach metamorphosis as control tadpoles, but the transgenic tadpoles are twice as large. After metamorphosis, the transgenic frogs grow at a greatly accelerated rate and develop skeletal abnormalities reminiscent of acromegaly. The transgenic frogs are larger than mature frogs in a few months and die in about 1 year. At as early as 10 months of age, the males have mature sperm. We conclude that the growth-promoting effects of GH in this amphibian closely resemble those described for mammals. Although excess GH increases the size of the tadpole, it does not alter the developmental programs involved in metamorphosis.
A platelet–endothelium interaction mediated by lectin-like oxidized low-density lipoprotein receptor-1
Authors: Kakutani Makoto , Masaki Tomoh , Sawamura Tatsuya
Published: July 2002

One crucial role of endothelium is to keep the innermost surface of a blood vessel antithrombotic. However, the endothelium also expresses prothrombotic molecules in response to various stimuli. The balance between the antithrombotic and prothrombotic nature of the endothelium is lost under certain conditions. During atherosclerosis, the attachment of platelets to the vessel surface has been suggested to promote the proliferation of smooth muscle cells and intimal thickening as well as to affect the prognosis of the disease directly through myocardial infarction and stroke. Dysfunctional endothelium, which is often a result of the action of oxidized low-density lipoprotein (OxLDL), tends to be more procoagulant and adhesive to platelets. Herein, we sought the possibility that the endothelial lectin-like OxLDL receptor-1 (LOX-1) is involved in the platelet–endothelium interaction and hence directly in endothelial dysfunction. LOX-1 indeed worked as an adhesion molecule for platelets. The binding of platelets was inhibited by a phosphatidylserine-binding protein, annexin V, and enhanced by agonists for platelets. These results suggest that negative phospholipids exposed on activation on the surface of platelets are the epitopes for LOX-1. Notably, the binding of platelets to LOX-1 enhanced the release of endothelin-1 from endothelial cells, supporting the induction of endothelial dysfunction, which would, in turn, promote the atherogenic process. LOX-1 may initiate and promote atherosclerosis, binding not only OxLDL but also platelets.
Distinct roles of the NH
2
- and COOH-terminal domains of the protein inhibitor of activated signal transducer and activator of transcription (STAT) 1 (PIAS1) in cytokine-induced PIAS1–Stat1 interaction
Authors: Liao Jiayu , Fu Yubin , Shuai Ke
Published: July 2002

STATs are activated by tyrosine phosphorylation on cytokine stimulation. A tyrosine-phosphorylated STAT forms a functional dimer through reciprocal Src homology 2 domain (SH2)–phosphotyrosyl peptide interactions. IFN treatment induces the association of PIAS1 and Stat1, which results in the inhibition of Stat1-mediated gene activation. The molecular basis of the cytokine-dependent PIAS1–Stat1 interaction has not been understood. We report here that a region near the COOH terminus of PIAS1 (amino acids 392–541) directly interacts with the NH
2
-terminal domain of Stat1 (amino acids 1–191). A mutant PIAS1 lacking the Stat1-interacting domain failed to inhibit Stat1-mediated gene activation. By using a modified yeast two-hybrid assay, we demonstrated that PIAS1 specifically interacts with the Stat1 dimer, but not tyrosine-phosphorylated or -unphosphorylated Stat1 monomer. In addition, whereas the NH
2
-terminal region of PIAS1 does not interact with Stat1, it serves as a modulatory domain by preventing the interaction of the COOH-terminal domain of PIAS1 with the Stat1 monomer. Thus, the cytokine-induced PIAS1–Stat1 interaction is mediated through the specific recognition of the dimeric form of Stat1 by PIAS1.
NMR structures of three single-residue variants of the human prion protein
Authors: Calzolai Luigi , Lysek Dominikus A. , Güntert Peter , von Schroetter Christine , Riek Roland , Zahn Ralph , Wüthrich Kurt
Published: July 2002

The NMR structures of three single-amino acid variants of the C-terminal domain of the human prion protein, hPrP(121–230), are presented. In hPrP(M166V) and hPrP(R220K) the substitution is with the corresponding residue in murine PrP, and in hPrP(S170N) it is with the corresponding Syrian hamster residue. All three substitutions are in the surface region of the structure of the cellular form of PrP (PrP
C
) that is formed by the C-terminal part of helix 3, with residues 218–230, and a loop of residues 166–172. This molecular region shows high species variability and has been implicated in specific interactions with a so far not further characterized “protein X,” and it is related to the species barrier for transmission of prion diseases. As expected, the three variant hPrP(121–230) structures have the same global architecture as the previously determined wild-type bovine, human, murine, and Syrian hamster prion proteins, but with the present study two localized “conformational markers” could be related with single amino acid exchanges. These are the length and quality of definition of helix 3, and the NMR-observability of the residues in the loop 166–172. Poor definition of the C-terminal part of helix 3 is characteristic for murine PrP and has now been observed also for hPrP(R220K), and NMR observation of the complete loop 166–172 has so far been unique for Syrian hamster PrP and is now also documented for hPrP(S170N).
Energetics of the HIV gp120-CD4 binding reaction
Authors: Myszka David G. , Sweet Raymond W. , Hensley Preston , Brigham-Burke Michael , Kwong Peter D. , Hendrickson Wayne A. , Wyatt Richard , Sodroski Joseph , Doyle Michael L.
Published: July 2002

HIV infection is initiated by the selective interaction between the cellular receptor CD4 and gp120, the external envelope glycoprotein of the virus. We used analytical ultracentrifugation, titration calorimetry, and surface plasmon resonance biosensor analysis to characterize the assembly state, thermodynamics, and kinetics of the CD4-gp120 interaction. The binding thermodynamics were of unexpected magnitude; changes in enthalpy, entropy, and heat capacity greatly exceeded those described for typical protein-protein interactions. These unusual thermodynamic properties were observed with both intact gp120 and a deglycosylated and truncated form of gp120 protein that lacked hypervariable loops V1, V2, and V3 and segments of its N and C termini. Together with previous crystallographic studies, the large changes in heat capacity and entropy reveal that extensive structural rearrangements occur within the core of gp120 upon CD4 binding. CD spectral studies and slow kinetics of binding support this conclusion. These results indicate considerable conformational flexibility within gp120, which may relate to viral mechanisms for triggering infection and disguising conserved receptor-binding sites from the immune system.
Computational evidence in favor of a two-state, two-mode model of the retinal chromophore photoisomerization
Authors: González-Luque Remedios , Garavelli Marco , Bernardi Fernando , Merchán Manuela , Robb Michael A. , Olivucci Massimo
Published: July 2002

In this paper we use
ab initio
multiconfigurational second-order perturbation theory to establish the intrinsic photoisomerization path model of retinal chromophores. This is accomplished by computing the ground state (
S
0
) and the first two singlet excited-state (
S
1
,
S
2
) energies along the rigorously determined photoisomerization coordinate of the rhodopsin chromophore model 4-
cis
-γ-methylnona-2,4,6,8-tetraeniminium cation and the bacteriorhodopsin chromophore model all-
trans
-hepta-2,4,6-trieniminium cation in isolated conditions. The computed
S
2
and
S
1
energy profiles do not show any avoided crossing feature along the
S
1
reaction path and maintain an energy gap >20 kcal⋅mol
−1
. In addition, the analysis of the charge distribution shows that there is no qualitative change in the
S
2
and
S
1
electronic structure along the path. Thus, the
S
1
state maintains a prevalent ionic (hole–pair) character whereas the
S
2
state maintains a covalent (dot–dot) character. These results, together with the analysis of the
S
1
reaction coordinate, support a two-state, two-mode model of the photoisomerization that constitutes a substantial revision of the previously proposed models.
Cell sorting is analogous to phase ordering in fluids
Authors: Beysens D. A. , Forgacs G. , Glazier J. A.
Published: July 2002

Morphogenetic processes, like sorting or spreading of tissues, characterize early embryonic development. An analogy between viscoelastic fluids and certain properties of embryonic tissues helps interpret these phenomena. The values of tissue-specific surface tensions are consistent with the equilibrium configurations that the Differential Adhesion Hypothesis predicts such tissues reach after sorting and spreading. Here we extend the fluid analogy to cellular kinetics. The same formalism applies to recent experiments on the kinetics of phase ordering in two-phase fluids. Our results provide biologically relevant information on the strength of binding between cell adhesion molecules under near-physiological conditions.
Solvent dependence of dynamic transitions in protein solutions
Authors: Réat Valerie , Dunn Rachel , Ferrand Michel , Finney John L. , Daniel Roy M. , Smith Jeremy C.
Published: July 2002

A transition as a function of increasing temperature from harmonic to anharmonic dynamics has been observed in globular proteins by using spectroscopic, scattering, and computer simulation techniques. We present here results of a dynamic neutron scattering analysis of the solvent dependence of the picosecond-time scale dynamic transition behavior of solutions of a simple single-subunit enzyme, xylanase. The protein is examined in powder form, in D
2
O, and in four two-component perdeuterated single-phase cryosolvents in which it is active and stable. The scattering profiles of the mixed solvent systems in the absence of protein are also determined. The general features of the dynamic transition behavior of the protein solutions follow those of the solvents. The dynamic transition in all of the mixed cryosolvent–protein systems is much more gradual than in pure D
2
O, consistent with a distribution of energy barriers. The differences between the dynamic behaviors of the various cryosolvent protein solutions themselves are remarkably small. The results are consistent with a picture in which the picosecond-time scale atomic dynamics respond strongly to melting of pure water solvent but are relatively invariant in cryosolvents of differing compositions and melting points.
Mechanical bases of frequency tuning and neural excitation at the base of the cochlea: Comparison of basilar-membrane vibrations and auditory-nerve-fiber responses in chinchilla
Authors: Ruggero Mario A. , Narayan S. Shyamla , Temchin Andrei N. , Recio Alberto
Published: July 2002

We review the mechanical origin of auditory-nerve excitation,
focusing on comparisons of the magnitudes and phases of
basilar-membrane (BM) vibrations and auditory-nerve fiber responses to
tones at a basal site of the chinchilla cochlea with characteristic
frequency ≈ 9 kHz located 3.5 mm from the oval window. At this
location, characteristic frequency thresholds of fibers with high
spontaneous activity correspond to magnitudes of BM displacement or
velocity in the order of 1 nm or 50 μm/s. Over a wide range of
stimulus frequencies, neural thresholds are not determined solely by BM
displacement but rather by a function of both displacement and
velocity. Near-threshold, auditory-nerve responses to low-frequency
tones are synchronous with peak BM velocity toward scala tympani but at
80–90 dB sound pressure level (in decibels relative to 20
microPascals) and at 100–110 dB sound pressure level responses undergo
two large phase shifts approaching 180°. These drastic phase changes
have no counterparts in BM vibrations. Thus, although at threshold
levels the encoding of BM vibrations into spike trains appears to
involve only relatively minor signal transformations, the polarity of
auditory-nerve responses does not conform with traditional views of how
BM vibrations are transmitted to the inner hair cells. The response
polarity at threshold levels, as well as the intensity-dependent phase
changes, apparently reflect micromechanical interactions between the
organ of Corti, the tectorial membrane and the subtectorial fluid,
and/or electrical and synaptic processes at the inner hair cells.
Attributes of an alluvial river and their relation to water policy and management
Authors: Trush William J. , McBain Scott M. , Leopold Luna B.
Published: July 2002

Rivers around the world are being regulated by dams to accommodate
the needs of a rapidly growing global population. These regulatory
efforts usually oppose the natural tendency of rivers to flood, move
sediment, and migrate. Although an economic benefit, river regulation
has come at unforeseen and unevaluated cumulative ecological costs.
Historic and contemporary approaches to remedy environmental losses
have largely ignored hydrologic, geomorphic, and biotic processes that
form and maintain healthy alluvial river ecosystems. Several commonly
known concepts that govern how alluvial channels work have been
compiled into a set of “attributes” for alluvial river integrity.
These attributes provide a minimum checklist of critical geomorphic and
ecological processes derived from field observation and
experimentation, a set of hypotheses to chart and evaluate strategies
for restoring and preserving alluvial river ecosystems. They can guide
how to (
i
) restore alluvial processes below an existing
dam without necessarily resorting to extreme measures such as
demolishing one, and (
ii
) preserve alluvial river
integrity below proposed dams. Once altered by dam construction, a
regulated alluvial river will never function as before. But a
scaled-down morphology could retain much of a river's original
integrity if key processes addressed in the attributes are explicitly
provided. Although such a restoration strategy is an experiment, it may
be the most practical solution for recovering regulated alluvial river
ecosystems and the species that inhabit them. Preservation or
restoration of the alluvial river attributes is a logical policy
direction for river management in the future.
Parameters of self-organization inHydraaggregates
Authors: Technau Ulrich , Cramer von Laue Christoph , Rentzsch Fabian , Luft Susanne , Hobmayer Bert , Bode Hans R. , Holstein Thomas W.
Published: July 2002

Self-organization has been demonstrated in a variety of systems ranging from chemical-molecular to ecosystem levels, and evidence is accumulating that it is also fundamental for animal development. Yet, self-organization can be approached experimentally in only a few animal systems. Cells isolated from the simple metazoanHydracan aggregate and form a complete animal by self-organization. By using this experimental system, we found that clusters of 5–15 epithelial cells are necessary and sufficient to formde novohead-organizing centers in an aggregate. Such organizers presumably arise by a community effect from a small number of cells that express the conservedHyBra1andHyWntgenes. These local sources then act to pattern and instruct the surrounding cells as well as generate a field of lateral inhibition that ranges up to 1,000 μm. We propose that conserved patterning systems in higher animals originate from extremely robust and flexible molecular self-organizing systems that were selected for during early metazoan evolution.
Novel features of the XRN-family in
Arabidopsis
: Evidence that AtXRN4, one of several orthologs of nuclear Xrn2p/Rat1p, functions in the cytoplasm
Authors: Kastenmayer J. P. , Green P. J.
Published: July 2002

The 5′-3′ exoribonucleases Xrn1p and Xrn2p/Rat1p function in the
degradation and processing of several classes of RNA in
Saccharomyces cerevisiae
. Xrn1p is the main enzyme
catalyzing cytoplasmic mRNA degradation in multiple decay pathways,
whereas Xrn2p/Rat1p functions in the processing of rRNAs and small
nucleolar RNAs (snoRNAs) in the nucleus. Much less is known about the
XRN-like proteins of multicellular eukaryotes; however, differences in
their activities could explain differences in mRNA degradation between
multicellular and unicellular eukaryotes. One such difference is the
lack in plants and animals of mRNA decay intermediates like those
generated in yeast when Xrn1p is blocked by poly(G) tracts that are
inserted within mRNAs. We investigated the XRN-family in
Arabidopsis thaliana
and found it to have several novel
features. First, the
Arabidopsis
genome contains three
XRN-like genes (
AtXRN
s) that are structurally similar to
Xrn2p/Rat1p, a characteristic unique to plants. Furthermore, our
experimental results and sequence database searches indicate that Xrn1p
orthologs may be absent from higher plants. Second, the lack of poly(G)
mRNA decay intermediates in plants cannot be explained by the activity
of the AtXRNs, because they are blocked by poly(G) tracts. Finally,
complementation of yeast mutants and localization studies indicate that
two of the AtXRNs likely function in the nucleus, whereas the third
acts in the cytoplasm. Thus, the XRN-family in plants is more complex
than in other eukaryotes, and, if an XRN-like enzyme plays a role in
mRNA decay in plants, the likely participant is a cytoplasmic
Xrn2p/Rat1p ortholog, rather than an Xrn1p ortholog.
TAF250 is required for multiple developmental events in
Drosophila
Authors: Wassarman David A. , Aoyagi Norikazu , Pile Lori A. , Schlag Erin M.
Published: July 2002

The TFIID transcription initiation complex is composed of TBP
and multiple TAFs. Studies in unicellular systems indicate that TAF250
is required for progression through G
1
/S of the cell
cycle and repression of apoptosis. Here we extend these
in vivo
studies by determining the developmental
requirements for TAF250 in a multicellular organism,
Drosophila
.
TAF250
mutants were isolated
in a genetic screen that also yielded
TAF60
and
TAF110
mutants, indicating that TAFs function
coordinately to regulate transcription. Null alleles of
TAF250
are recessive larval lethal. However,
combinations of weak loss-of-function
TAF250
alleles
survive to adulthood and reveal requirements for TAF250 during ovary,
eye, ocelli, wing, bristle, and terminalia development as well as
overall growth of the fly. These phenotypes suggest roles for TAF250 in
regulating the cell cycle, cell differentiation, cell proliferation,
and cell survival. Finally, molecular analysis of
TAF250
mutants reveals that the observed phenotypes are caused by mutations in
a central region of TAF250 that is conserved among metazoan organisms.
This region is contained within the TAF250 histone acetyltransferase
domain, but the mutations do not alter the histone acetyltransferase
activity of TAF250
in vitro
, indicating that some other
aspect of TAF250 function is affected. Because this region is not
conserved in the yeast TAF250 homologue, TAF145, it may define an
activity for TAF250 that is unique to higher eukaryotes.
Osmotic stress, crowding, preferential hydration, and binding: A comparison of perspectives
Authors: Parsegian V. A. , Rand R. P. , Rau D. C.
Published: July 2002

There has been much confusion recently about the relative merits of different approaches, osmotic stress, preferential interaction, and crowding, to describe the indirect effect of solutes on macromolecular conformations and reactions. To strengthen all interpretations of measurements and to forestall further unnecessary conceptual or linguistic confusion, we show here how the different perspectives all can be reconciled. Our approach is through the Gibbs-Duhem relation, the universal constraint on the number of ways it is possible to change the temperature, pressure, and chemical potentials of the several components in any thermodynamically defined system. From this general Gibbs-Duhem equation, it is possible to see the equivalence of the different perspectives and even to show the precise identity of the more specialized equations that the different approaches use.
Macedonians in Greece and Albania: A Comparative Study of Recent Developments*
Authors: Hill Peter
Published: July 2002

It has been said that the Berlin Wall fell in 1989 but the wall around Greece is still standing. It is ironic that, while the governments of Albania, Bulgaria and Rumania have, in recent years, taken measures to safeguard the rights of national minorities, the Greek government continues to stonewall on its own national minorities while fomenting rebellion among those in other countries. Nevertheless, the end of the Cold War has benefited the Macedonian minority in Greece. Greece has lost its paramount strategic importance for the western countries, which are now less likely to cast a blind eye on human rights abuses in that country. Conditions for the Macedonians in Greece have improved somewhat as individual members of the minority have become emboldened to demand their rights in public in recent years. They have attracted the attention of the U.S. State Department, Amnesty International and the Human Rights Watch/Helsinki Watch, all the more so due to the heavy-handed attempts by the Greek authorities to silence recalcitrant members of the minority, as described below. The U.S. Department of State (1995: Greece 12) notes that the Greek government “continues to harass and intimidate some of these people.”
Rapid assessment and response: methods for developing public health responses to drug problems
Authors: Stimson Gerry V. , Fitch Chris , Rhodes Tim , Ball Andrew
Published: July 2002

Rapid assessments are used increasingly to assist in the development of public health interventions for drug problems. They have been used to assess drug use and its health consequences, alert governments to the need to intervene, build alliances between community groups and health organisations, identify appropriate interventions (at the individual, community and structural level), indicate obstacles to interventions, test their feasibility and help implement and assess them. Rapid assessment and response (RAR) methods have been developed because: conventional social science and routine drug surveillance information systems often fail to deliver relevant information; many drug problems change faster than social research projects can deliver; and because inappropriate interventions may be developed unless based on good evidence and analysis. Originating as a research method, and often used by international agencies and conducted by external consultants, RAR is a rapidly evolving approach to analysing situations in order to develop interventions. RAR is becoming a tool for developing responses and not merely for conducting rapid “assessments”.
Plasma cytokine response in mice with bacterial infection
Authors: Abram Maja , Vučković Darinka , Wraber Branka , Dorić Miljenko
Published: July 2002

Background: Exposure to microorganisms elicts the production of cytokines. These soluble factors enhance several innate immune functions and regulate the ensuing specific immune response aimed at limiting the spread of infection.

Aim: This study was undertaken to quantify the plasma levels of pro‐inflammatory cytokines during the course of primary Listeria monocytogenes and Campylobacter jejuni infection. Using an
in vivo infection the relationship between endogenous cytokines and the bacterial number in the liver of infected animals was examined.

Methods: C57BL/6 mice were infected by the intraperitoneal route. At different time points we determined the number of colony‐forming units of bacteria in the liver of infected animals and paralled these with the plasma levels of interferon‐gamma (IFN‐γ), tumor necrosis factor‐alpha (TNF‐α) and interleukin‐6 (IL‐6) measured by enzyme
immunoassays.

Results: L. monocytogenes infection lasted 10–11 days. IFN‐γ production occurred in the early phase but was more pronounced after day 4, following the appearance of specific immunity. The duration of experimental campylobacteriosis was 15 days. Early IFN‐γ production was not significant but a progressive rise of this cytokine in plasma was seen during the second week post infection. Mice produced measurable amounts of plasma TNF‐α immediately after being given viable L. monocytogenes, peaking on day 2–3 when the greatest number of bacteria was present in the examined organs. During C. jejuni infection plasma TNF‐α was produced in a similar manner, but the highest concentrations were found a few days later than in listeriosis, in correlation with the different course of campylobacteriosis. The quantity of IL‐6 increased and decreased in concordance with clearance of
L. monocytogenes and the clinical status of the animals. C. jejuni did not promote the induction of this cytokine. This is to some extent an unusual finding. With respect to the role of IL‐6 in Th2 responses and antibody production, the appearance of this cytokine in campylobacteriosis was more expected.

Discussion: During systemic bacterial infection, a network of pro‐inflammatory cytokines is activated and blood levels of these cytokines are elevated, albeit inconsistently, with large individual variations and depending on microbial characteristics and structure.
The possible anti‐inflammatory role of circulating human leukocyte antigen levels in women with endometriosis after treatment with danazol and leuprorelin acetate depot
Authors: Matalliotakis Ioannis M. , Athanassakis Irene , Goumenou Anastasia G. , Neonaki Maria A. , Koumantakis Emmanuil E. , Vassiliadis Simon , Koumantakis Evgenios E.
Published: July 2002

Background: Endometriosis is defined as an inflammatory condition of the female reproductive tract, a state often associated with infertility and miscarriage. Many exogenously administered factors (treatments) control the disease via as yet unknown pathways. Possible candidate molecules involved in these mechanisms could be the serum‐soluble human leukocyte antigens (sHLA) that have been detected in a variety of human body fluids and that are associated with several diseases.

Aims: We here examine how danazol and leuprorelin acetate depot treatments exert their anti‐inflammatory action. It is plausible that subtle alterations mediated by these treatments and in relation to sHLA may explain the pathophysiology of endometriosis and provide insights towards new therapeutic protocols.

Methods: Indirect enzyme‐linked immunosorbent assay (ELISA), using specific monoclonal antibodies, determined serum‐soluble class‐I and class‐II HLA levels. ELISA readings from treated women were compared with normal healthy subjects.

Results: Serum‐soluble class‐I and class‐II HLA levels are statistically significantly lower
(P < 0.001) in women with endometriosis than in the control groups. However, danazol but not leuprorelin acetate depot administration augments soluble HLA class I and class II (P < 0.01
and P < 0.001, respectively) to normal levels during the treatment period, an increase that may account for the anti‐inflammatory effect and the remission observed.

Conlusions: It is shown that one of the underlying causes of endometriosis may be the lack of both circulating class‐I and class‐II antigen levels. Danazol administration acts via an induced release of these antigens, whose presence correlates with the degree of the inflammatory alleviation obtained. We thus provide evidence that the inflammatory state of the disease appears to be associated with soluble HLA levels because, 3 months after ceasing therapy, the circulating antigens in the serum return to the same levels that correspond to the pathological condition.
Pharmacological evidence supporting a role for IL‐1, IL‐2 and serotonin in the inflammation induced by Schistosoma mansoni Soluble Egg Antigen (SEA) in rat paws
Authors: Pacheco C. M. F. , Tavares C. A. P. , Coelho P. M. Z. , Rocha O. A. , Santos J. M. M. , Prado F. R. M. , Francischi J. N.
Published: July 2002

This study intended to characterize pharmacologically the mediator(s ) released in the inflammation induced by Soluble Egg Antigen (SEA), the main antigen released from eggs of Schistosoma mansoni, in rat hindpaws . A single intraplantar injection of 0.1–100 μg SEA at day zero induced a dose‐dependent increase in the volume of rat hindpaws characterizing an oedema of quick onset (within 15 min) and
4 h‐duration, which was confirmed by his topathological analys is of the paws . A second injection of SEA
in the same paw (1–10 μg) 28 days later induced an increased dose ‐dependent oedematogenic response.
The early oedematogenic response following SEA sensitization was derived from serotonin release and
interleukin‐1 (IL‐1), since treatment with either pizotifen or anantibody against IL‐1, reduced the
response by 60% and 48%, respectively. The increased oedematogenic response derived from SEA‐challenge (10 μg) of rat paws derived from a local rather than systemic reaction, since it was not
observed if the sensitization was in the contralateral paw or the peritoneal cavity of the animals. Chronic
tre atment with inhibitors of IL‐2 synthesis / release such as cyclosporin or dexamethasone during the
sens itization phase reduced the oedematogenic response due to SEA challenge by 51% and 55%,
respectively. These data suggested that SEA‐challenge was immune‐derived and dependent of IL‐2 release. It
is discussed the association between cytokine release and the resistance of rats to S. mans o ni infe ction.
Differential regulation of C‐C chemokines during fibroblast‐monocyte interactions: adhesion vs. inflammatory cytokine pathways
Authors: Zickus C. , Kunkel S. L. , Simpson K. , Evanoff H. , Glass M. , Strieter R. M. , Lukacs N. W.
Published: July 2002

The cell‐to‐ce ll interactions during chronic inflammatory diseases likely contribute to leukocyte accumulation leading to increased pathology and organ dys ‐function. In particular, there is a paucity of
information relating to the maintenance of chronic fibrotic diseases . Using a lung fibroblast line and
enriched monocyte populations , we have investigated the activational events which contribute to the production
of two C‐C chemokines , macrophage inflammatory protein‐1 alpha (MIP‐1α ) and monocyte
chemoattractant protein‐1 (MCP‐1), during fibroblas tmonocyte interactions . Neither the fibroblast cell line
(16 lu) nor isolated monocytes alone produced significant levels of MIP‐1α or MCP‐1. However, when
isolated monocytes were layered onto 16 lu fibroblas tmonolayers as ignificant increase in MIP‐1α and MCP‐
1 production was observed. The use of fixed cell populations indicated that the MIP‐1α was derived
from monocytes and MCP‐1 from both cell populations. To examine the molecules which wer erequired
for chemokine production during the interaction, specific antibodies were used in the co‐cultures .
Blocking β3‐integrin interactions s ignificantly inhibited MIP‐1α production. In contrast, beta‐integr in interactions had no effect on the MCP‐1 production, while, neutralization of TNF significantly decreased
MCP‐1 production during the co‐culture . These data indicate that fibroblast–monocyte inte ractions
induce chemokine production through different mechanisms and a combination of these responses
may contribute to the maintenance of the mononuclear cell accumulation during diseaseprogression.
Glucocorticoid receptor expression in human bronchial epithelial cells: effects of smoking and COPD
Authors: Verheggen M. M. , Adriaansen-Soeting P. W. C. , Berrevoets C. A. , van Hal P. Th. W. , Brinkmann A. O. , Hoogsteden H. C. , Versnel M. A.
Published: July 2002

Previously, we found that inflammatory mediators modulated the number and binding affinity of glucocorticoid receptors (GR) in human bronchial epithelial cell lines . In this study we investigated whether smoking and chronic obstructive pulmonary disease (COPD), both characterized by airway inflammation with increased levels of inflammatory mediators , affect GR characteristics in cultured human bronchial
epithelial cells (HBEC). A statisticallys ignificant difference was found be tween the dissociation constant
(Kd) values in HBEC from smoking (Kd = 0.98 ± 0.08 nM; n = 6) and nonsmoking controls (Kd = 0.76 ± 0.10 nM, p = 0.03; n = 5), but no significant difference was found between the mean number of binding sites . Our results are the first indication that cultured HBEC from smokers possess GR with a lower binding affinity. This may result from the in flammation found in the airways from smokers . Further more, these results provide furthere vidence that the bronchial
epithelium may be an actual target for inhaled glucocor ticoid therapy.
Developmental Toxicity of Levo-Alpha-Acetylmethadol (LAAM) in Tolerant Rats
Authors: York Raymond G. , Denny Kevin H. , Moody David E. , Alburges Mario E.
Published: July 2002

Mated Crl:CD VAF/Plus female rats, in a range-finding study ( n = 5–6 per dose) and a subsequent definitive study ( n = 30 per dose) were used to determine the developmental toxicity, including the teratogenic potential of levo-alpha-acetyhnethadol (LAAM) hydrochloride, in tolerant rats. Tolerance was induced by initially administering the drug by gavage (10 ml/kg) at 2 mg/kg/day and increasing the dose every 2 weeks for 12 weeks until the doses of 2, 6, 9, 12, and 15, or 2, 6, and 12 mg/kg/day were achieved in the range-finding or definitive study, respectively. Females were then mated to stock males and treated throughout mating and gestation. Controls received distilled water on a similar regimen. The range-finding experiment was used for initial clinical evaluations and to determine tissue concentrations of LAAM and metabolites. In plasma, liver, and brain collected from dams and fetuses pooled by litter on gestation day 20, LAAM and its two N-demethylated metabolites, norLAAM and dinorLAAM, showed dose-dependent increases in concentration and in tissue to plasma ratios. Tissue to dam plasma ratios were highest in dam liver (17–60), intermediate in fetal liver (3–16), and fetal brain (3–14), and lowest in dam brain (0.8–5.6) and fetal plasma (0.3–2.1). In the definitive study, caesarean section examinations were performed following euthanization on gestation day 20 on all surviving females followed by teratologic examination of the fetuses. Drug-related outcomes, including increased activity, secondary hair loss, scabbing, focal swelling, and material around the nose, were exhibited by all groups receiving LAAM. Maternal toxicity was evident as decreased body weights, with maximum reduction at the 6-mg/kg/day dose, and reduction in feed consumption. There was also evidence of developmental toxicity in the form of postimplantaüon losses at all doses of LAAM. There were no deaths attributable to LAAM. No grossly observable visceral or skeletal anomalies related to LAAM were observed in the fetuses. In conclusion, the no-observable-effect level when administered to tolerant rats was less than 2 mg/kg/day with regard to clinical signs, body weight, body weight gain, and feed consumption, and with regard to developmental toxicity as reflected by postimplantaüon losses. Despite maternal and developmental toxicity, there was no evidence of selective fetal toxicity or teratogenic activity attributable to LAAM.
Conference report: ‘L'età dei totalitarismi. Silone e la cultura letteraria e politica degli anni venti-trenta’ 29 April–1 May 2001, L'Aquila/Pescina
Authors: Holmes Deborah
Published: July 2002

Organized by the ‘Comitato nazionale per il centenario della nascita di Ignazio Silone’, this conference was the culmination of a year of events. Held in collaboration with the three universities of the Abruzzo, its aim was to avoid an overly celebratory tone and to provide a working forum for ongoing research. The theme was not just Silone as writer and political activist but also the broader context of his early career. The organizers wanted to make a serious academic contribution to the debates which have raged over the last three years as to whether Silone collaborated with the Fascist political police. The press has created the impression that there are two fronts or camps: those who believe Silone was an informer (‘led’ by the historians Maurizio Canali and Dario Biocca, co-authors of the L'informatore: Silone, i comunisti e la polizia1) and those who believe the evidence has been exaggerated or even invented (Mimmo Franzinelli, author of I tentacoli dell'Ovra2 and Giuseppe Tamburrano, director of the Fondazione Pietro Nenni). For the. rst time, this centenary conference set out to bring the two sides together away from media clamour and, unsurprisingly, they appeared neither united in themselves nor united against each other.
Predictors of relapse to heavy drinking in alcohol dependent subjects following alcohol detoxification—the role of quality of life measures, ethnicity, social class, cigarette and drug use
Authors: FOSTER J. H. , MARSHALL E. J. , PETERS T. J.
Published: July 2002

Sixty DSM‐IV alcohol dependent adults (39 males, 21 females) admitted to a voluntary sector alcohol detoxification unit in South London were studied. Socio‐demographic data and information on level of alcohol dependence, quality of life, family history, cigarette smoking and the use of prescription/illicit drugs were collected. The subjects were followed‐up at 12 weeks and subdivided into two groups, relapse and non‐relapse. A relapse was defined as drinking 21 units or more per week for males and 14 units or more per week for females. Data were analysed for baseline and 12‐week follow‐up comparisons. At 12 weeks, 58 (97%) subjects (38 males, 20 females) were successfully followed‐up and 36/58 (62%) had relapsed. After controlling for a Type I error there were significant differences between the relapse and non‐relapse subgroups at 12‐week followup on the following outcome measures; depression, life situation, withdrawal symptoms, energy, emotional reactions and social isolation. There were no significant differences at baseline between the relapse and nonrelapse subgroups for most of the socio‐demographic variables, but Irish nationality and membership of lower social classes (IV and V) were associated with relapse. Major predictors of relapse at baseline after a forward stepwise logistic regression were (in order of increasing statistical significance) Irish nationality, lower social class, greater number of cigarettes smoked and disturbed sleep. The findings are discussed with reference to their consistency with existing research and potential clinical implications.
Symptoms and their Relationship to Disability Following Treatment for Lower Extremity Tumours
Authors: Davis Aileen M. , Punniyamoorthy Sajeevan , Griffin Anthony M. , Wunder Jay S. , Bell Robert S.
Published: July 2002

Purpose. The aims of this study were to describe the symptoms
experienced by patients in the first year following treatment for lower extremity sarcoma
by limb conservation and to describe the relationship between symptoms and physical
disability.

Subjects. Eighty consecutive patients treated for primary bone or
soft tissue sarcoma (STS) of the lower limb who were treated with limb preservation
surgery.

Methods. Subjects were evaluated by questionnaire at 6 weeks,
and 3, 6, and 12 months post surgery. They identified
whether they experienced any of the following symptoms: pain, stiffness, fatigue,
weakness, limited range of motion, or swelling.The Toronto Extremity Salvage Score (TESS),
a measure of physical disability, was also completed. Frequency of symptoms over time
was calculated and change was evaluated using the Cochrane test. The relationship of symptoms to
disability was analyzed with regression methods.

Results. The mean age was 43.0, SD=20.4 with a gender ratio of 1:1.
There were 38 bone tumours and 42 STS.The most frequently reported symptoms were:
stiffness 48 (60%), weakness 41 (51%), fatigue 26 (33%), and pain 25 (31%) at 6 weeks.
Stiffness and fatigue decreased and plateaued by 3 months. Complaints of weakness and
pain continued to decrease over time. At 6 weeks, pain, stiffness, weakness and limited motion
predicted disability in both univariate and multivariate analyses. At 12 months, pain, stiffness,
fatigue, weakness and limited motion were significant predictors of the TESS in univariate
analysis with only pain, stiffness and limited motion significant predictors in the
multivariate model.

Discussion. Pain, stiffness, fatigue, weakness and limited motion are
common symptoms with stiffness and weakness decreasing significantly over time.
The symptoms predictive of disability differ between the acute and late phases of recovery.
cdc12p, a Protein Required for Cytokinesis in Fission Yeast, Is a Component of the Cell Division Ring and Interacts with Profilin
Authors: Chang Fred , Drubin David , Nurse Paul
Published: July 2002

As in many other eukaryotic cells, cell division in fission yeast depends on the assembly of an actin ring that circumscribes the middle of the cell. Schizosaccharomyces pombe cdc12 is an essential gene necessary for actin ring assembly and septum formation. Here we show that cdc12p is a member of a family of proteins including Drosophila diaphanous, Saccharomyces cerevisiae BNI1, and S. pombe fus1, which are involved in cytokinesis or other actin-mediated processes. Using indirect immunofluorescence, we show that cdc12p is located in the cell division ring and not in other actin structures. When overexpressed, cdc12p is located at a medial spot in interphase that anticipates the future ring site. cdc12p localization is altered in actin ring mutants. cdc8 (tropomyosin homologue), cdc3 (profilin homologue), and cdc15 mutants exhibit no specific cdc12p staining during mitosis. cdc4 mutant cells exhibit a medial cortical cdc12p spot in place of a ring. mid1 mutant cells generally exhibit a cdc12p spot with a single cdc12p strand extending in a random direction. Based on these patterns, we present a model in which ring assembly originates from a single point on the cortex and in which a molecular pathway for the functions of cytokinesis proteins is suggested. Finally, we found that cdc12 and cdc3 mutants show a syntheticlethal genetic interaction, and a proline-rich domain of cdc12p binds directly to profilin cdc3p in vitro, suggesting that one function of cdc12p in ring assembly is to bind profilin.
Regulated Membrane Localization of Tiam1, Mediated by the NH2-terminal Pleckstrin Homology Domain, Is Required for Rac-dependent Membrane Ruffling and C-Jun NH2-terminal Kinase Activation
Authors: Michiels Frits , Stam Jord C. , Hordijk Peter L. , Kammen Rob A. van der , Stalle Lisette Ruuls-Van , Feltkamp Constance A. , Collard John G.
Published: July 2002

Rho-like GTPases, including Cdc42, Rac, and Rho, regulate signaling pathways that control actin cytoskeletal structures and transcriptional activation. The Tiam1 gene encodes an activator of Rac1, and similarly to constitutively activated (V12)Rac1, overexpression of Tiam1 in fibroblasts induces the formation of membrane ruffles. Tiam1 contains a Dbl homology (DH) domain and adjacent pleckstrin homology (PH) domain, hallmarks for activators of Rho-like GTPases. Unique for Tiam1 are an additional PH domain and a Discs-large homology region in the NH2-terminal part of the protein. Here we show that both in fibroblasts and COS cells, membrane localization of Tiam1 is required for the induction of membrane ruffling. A detailed mutational analysis, in combination with confocal laser scanning microscopy and immunoelectron microscopy, demonstrates that the NH2-terminal PH domain of Tiam1, but not the DH-adjacent PH domain, is essential for membrane association. This NH2-terminal PH domain of Tiam1 can be functionally replaced by the myristoylated membrane localization domain of c-Src, indicating that the primary function of this PH domain is to localize the protein at the membrane. After serum starvation, both membrane association of Tiam1 and ruffling can be induced by serum, suggesting that receptor stimulation induces membrane translocation of Tiam1. Similar to V12Rac1, Tiam1 stimulates the activity of the c-Jun NH2-terminal kinase (JNK). This Rac-dependent stimulation of JNK also requires membrane association of Tiam1. We conclude that the regulated membrane localization of Tiam1 through its NH2-terminal PH domain determines the activation of distinct Rac-mediated signaling pathways.