bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectroscopic study of conformational changes accompanying self‐assembly of HCV core protein
Authors: Rodríguez‐Casado Arantxa , Molina Marina , Carmona Pedro
Published: October 2006

Electron microscopy and infrared and Raman spectroscopy have been used here to study the morphology, size distribution, secondary and tertiary structures of protein particles assembled from a truncated hepatitis C virus (HCV) core protein covering the first 120 aa. Particles of pure protein, having similar morphology and size distribution of those of nucleocapsids found in sera from HCV‐infected patients, have been visualized for the first time. The secondary structure of these protein particles involve β‐sheet enrichment in relation to its protein monomer. Tertiary/quaternary structure has also been studied using the dynamics of H/D exchange. With this aim infrared spectra were measured as a function of H/D exchange time and subsequently analyzed by principal component analysis and two‐dimensional correlation spectroscopy. Temporal dynamics of exchange for these protein particles were as follows: arginine residues exchanged first, followed by turn and unordered structures, followed by β‐sheets which may act as linkers of protein monomers. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Ca2+‐dependent conformational changes in the neuronal Ca2+‐sensor recoverin probed by the fluorescent dye Alexa647
Authors: Gensch Thomas , Komolov Konstantin E. , Senin Ivan I. , Philippov Pavel P. , Koch Karl‐Wilhelm
Published: October 2006

Recoverin belongs to the superfamily of EF‐hand Ca2+‐binding proteins and operates as a Ca2+‐sensor in vertebrate photoreceptor cells, where it regulates the activity of rhodopsin kinase GRK1 in a Ca2+‐dependent manner. Ca2+‐dependent conformational changes in recoverin are allosterically controlled by the covalently attached myristoyl group. The amino acid sequence of recoverin harbors a unique cysteine at position 38. The cysteine can be modified by the fluorescent dye Alexa647 using a maleimide‐thiol coupling step. Introduction of Alexa647 into recoverin did not disturb the biological function of recoverin, as it can regulate rhodopsin kinase activity like unlabeled recoverin. Performance of the Ca2+‐myristoyl switch of labeled recoverin was monitored by Ca2+‐dependent association with immobilized lipids using surface plasmon resonance spectroscopy. When the Ca2+‐concentration was varied, labeled myristoylated recoverin showed a 37%‐change in fluorescence emission and a 34%‐change in excitation intensity, emission and excitation maxima shifted by 6 and 18 nm, respectively. In contrast, labeled nonmyristoylated recoverin exhibited only minimal changes. Time‐resolved fluorescence measurements showed biexponentiell fluorescence decay, in which the slower time constant of 2 ns was specifically influenced by Ca2+‐induced conformational changes. A similar influence on the slower time constant was observed with the recoverin mutant RecE85Q that has a disabled EF‐hand 2, but no such influence was detected with the mutant RecE121Q (EF‐hand 3 is nonfunctional) that contains the myristoyl group in a clamped position. We conclude from our results that Alexa647 bound to cysteine 38 can monitor the conformational transition in recoverin that is under control of the myristoyl group. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Synthesis and fungicidal activity of N‐2‐(3‐methoxy‐4‐propargyloxy) phenethyl amides. Part 3: stretched and heterocyclic mandelamide oomyceticides
Authors: Lamberth Clemens , Kempf Hans‐Joachim , Križ Miroslav
Published: October 2006

Novel analogues of mandipropamid have been designed and prepared. The synthetic approach to these stretched and heterocyclic mandelamides is outlined. Biological data demonstrate their high efficacy against important plant diseases like tomato and potato late blight (Phytophthora infestans De Bary) and grape downy mildew (Plasmopara viticola Berliner & de Toni). Structure–activity relationship studies are discussed. Copyright © 2006 Society of Chemical Industry
Marjolin's Ulcer Arising at the Elbow: A Case Report and Literature Review
Authors: Ogawa B. , Chen M. , Margolis J. , Schiller F. J. , Schnall S. B.
Published: October 2006

Marjolin's ulcer is a squamous cell carcinoma that develops in posttraumatic scars and chronic wounds. It was first noted to be associated with chronic osteomyelitis in 1835 and is usually described occurring in lower extremity wounds. Suspicion of such lesions should be raised in chronic wounds demonstrating characteristic changes. Impaired immunologic activity in chronic wounds has also been shown to contribute to the pathologic process. Definitive treatment in the past has been amputation proximal to the tumor, however; recently, wide resection and radiation therapy have been used. According to Lifeso et al., wide local excision is unreliable and they recommend amputation in grade II or III disease and wide local excision in very small lesions that can be radically excised or in grade I lesions. We report a case of a Marjolin ulcer that developed at the elbow. Physicians should have a high index of suspicion in chronic wounds that are recalcitrant to therapy and should remember to biopsy all suspected lesions. Early recognition and definitive treatment are the mainstays ensuring the best prognosis.
“Social Robotics” und Mensch-Maschine-Interaktion
Authors: Echterhoff Gerald , Bohner Gerd , Siebler Frank
Published: October 2006

Zusammenfassung: Aus aktuellen Entwicklungen zur Mensch-Maschine-Interaktion (MMI), insbesondere auf dem wachsenden Feld der Social Robotics, entstehen neuartige Perspektiven für die sozialpsychologische Forschung. Da Computer und Roboter sich in besonderem Maße als Objekte einer Anthropomorphisierung eignen, sollten psychologische Zugänge auch in diesem Forschungsfeld hilfreich sein. Ausgehend von Unterscheidungen zwischen verschiedenen Typen dieser Maschinen werden mögliche Beiträge der Sozialpsychologie zur interdisziplinären Forschung und Entwicklung skizziert. Vorliegende Befunde zur sozialen Dimension der MMI werden vorgestellt und diskutiert: das Forschungsprogramm “Computer als soziale Akteure” sowie Ansätze zur Menschenähnlichkeit der Maschine als unabhängiger und abhängiger Variablen. Abschließend schlagen wir spezifische Themen für die zukünftige sozialpsychologische Forschung in drei klassischen Bereichen vor (Urteilsprozesse im Kontext der MMI, “interpersonelle” Prozesse und Intergruppenbeziehungen).
What do college students know about the ocean?
Authors: Cudaback Cynthia
Published: October 2006

A recent survey of students entering a college‐level course in introductory oceanography reveals that they feel a strong connection with, and curiosity about, the ocean. To guide this inherent curiosity into understanding and stewardship, educators need to know the ‘hooks,’ the topics and concepts that catch students' interests. According to a survey of 119 students at North Carolina State University‐Raleigh, some useful hooks are students' personal, emotional connection with the ocean, human impacts (especially pollution), exotic biology and cool technology.

Survey results further indicate that students already are gaining ocean knowledge from a wide variety of sources, and that the topics of interest to them can be organized using the Essential Principles of Ocean Literacy [Centers for Ocean Sciences Education Excellence (COSEE), 2005]. The students' general awareness of ocean science is a good basis upon which to build.
NASA science committee appointments
Authors: Zielinski Sarah
Published: October 2006

NASA Administrator Michael Griffin has made three new appointments to the NASA Advisory Council's (NAC) Science Committee, NASA announced on 22 September. Edward David, president of EED, Inc., and science advisor to the President from 1970 to 1973, will serve as the committee's chair. Also appointed to the committee were Owen Garriott, a retired scientist astronaut, and Alan Stern, executive director of the Space Science and Engineering Division of the Southwest Research Institute (San Antonio, Tex.).
Voyager 1 encounters new region of space
Authors: Zielinski Sarah
Published: October 2006

Voyager 1, which left Earth in 1977 and is now about 10 billion miles away has entered a region of space with strange anomalies, according to project scientist Ed Stone, former director of the Jet Propulsion Laboratory The spacecraft has encountered magnetic potholes and bumps—areas where the magnetic field of the heliosheath either nearly vanishes or doubles, respectively It also has encountered ‘anomalous cosmic rays’ that are less energetic, and thus less dangerous, than galactic cosmic rays.
Agriculture's role in reducing climate change
Authors: Zielinki Sarah
Published: October 2006

The United States could manage the nation's forest and agricultural lands in ways that would sequester more carbon and reduce U.S. emissions of carbon, according to two reports issued by the Pew Center on Global Climate Change on 21 September. The reports recommend a national strategy that could include policies such as regulating land use of privately owned forests, incentives for farmers, and changing public land practices. According to the reports, U.S. greenhouse gas emissions could be offset by one fifth through changes in agricultural land practices and the foresting of marginal agricultural lands, and the use of biofuels could reduce emissions by another 10 to 25 percent.
Using satellite data products to manage living marine resources
Authors: Friedl Lawrence , Wilson Cara , Chao Yi , Bograd Steven , Turner Woody
Published: October 2006

With the 2006 efforts by the U.S. Congress to renew the Magnuson‐Stevens Fishery Conservation and Management Act and the 2004 U.S. Commission on Ocean Policy report, issues regarding the management of living marine resources and the use of ocean observing systems are receiving significant attention. Internationally, the Group on Earth Observations (GEO; http://www.earthobservations.org) is highlighting efforts by national governments, including those of the U.S. government, to use Earth science measurements to support decision‐making for societal benefits. In addition, the U.S. National Oceanic and Atmospheric Administration (NOAA) is placing greater emphasis on ecosystem‐based approaches to addressing its management responsibilities.

Given the continuity, global coverage, and high temporal and spatial resolution of satellite observations, they represent important tools for monitoring and characterizing marine ecosystems. Most of the spatial features that are important to characterizing ecosystems (i.e., ocean fronts, eddies, convergence zones, river plumes, and coastal regions) cannot be adequately resolved without satellite data. However, the potential of satellite data to more fully enhance operational applications within NOAA Fisheries has not yet been realized, such as improving the accuracy of fisheries stock assessments and contributing to Integrated Ecosystem Assessments (IEAs).
George W. Wetherill (1925–2006)
Authors: Weissman Paul
Published: October 2006

George West Wetherill, a pioneer of geochronolgy and planetary science, passed away from heart failure at his home in Washington, D.C., on 19 July 2006, one month short of his 81st birthday Wetherill, director emeritus of the Carnegie Institution of Washington's Department of Terrestrial Magnetism, made major contributions to a wide variety of fields, including geochronology and the formation of the planets.

Wetherill was born in Philadelphia, Pa., on 12 August 1925. After service in the U.S. Navy in World War II, where he taught radar at the Naval Research Laboratory, he entered the University of Chicago on the G.I. Bill. Wetherill obtained four degrees, culminating in his Ph.D. in physics in 1953. He began work at Carnegie's Department of Terrestrial Magnetism in 1953 and became part of its geochronology group, working with Thomas Aldrich, George Tilton, and Gordon Davis.
Nonlinear internal waves from the Luzon Strait
Authors: Liu Cho‐Teng , Pinkel Robert , Klymak Jody , Hsu Ming‐Kuang , Chen Hsien‐Wen , Villanoy Cesar
Published: October 2006

In the northeastern South China Sea, fast westward moving nonlinear internal waves (NLIWs) emanate nearly daily from the Luzon Strait during spring tide. Their propagation speed of about 2.9 meters per second is faster than NLIWs previously observed in the world's oceans. The amplitudes of these waves reach 140 meters or more, and they are the largest free propagating NLIWs observed to date in the interior ocean. These NLIWs energize the top 1500 meters of the water column, moving water up and down at timescales as short as 20 minutes. While their associated energy density and energy flux are the largest observed to date, the exact source of these giant waves has yet to be determined.
Rover begins Mars crater exploration
Authors: Zielinski Sarah
Published: October 2006

A test image taken on 3 October by the Mars Reconnaissance Orbiter (MRO) was used to plan the next day's journey by the rover Opportunity as the rover began to explore its new target, Mars' Victoria Crater, NASA officials announced at a 6 October briefing. This image, and future ones, will be used in the planning of Opportunity's exploration of the crater, the largest and deepest yet to be explored on the planet.

MRO arrived at Mars in March, and in November it begins its prime mission, a search for evidence that water persisted on the planet for a long period of time. Beginning in late September, MRO's High Resolution Imaging Science Experiment (HiRise) camera began taking test images of the planet's surface, including one of Victoria Crater (Figure 1).
Transport Pathways for Clearance of Human Alzheimer's Amyloid β-Peptide and Apolipoproteins E and J in the Mouse Central Nervous System
Authors: Bell Robert D , Sagare Abhay P , Friedman Alan E , Bedi Gurrinder S , Holtzman David M , Deane Rashid , Zlokovic Berislav V
Published: October 2006

Amyloid β-peptide (Aβ) clearance from the central nervous system (CNS) maintains its low levels in brain. In Alzheimer's disease, Aβ accumulates in brain possibly because of its faulty CNS clearance and a deficient efflux across the blood—brain barrier (BBB). By using human-specific enzyme-linked immunosorbent assays, we measured a rapid 30 mins efflux at the BBB and transport via the interstitial fluid (ISF) bulk flow of human-unlabeled Aβ and of Aβ transport proteins, apolipoprotein E (apoE) and apoJ in mice. We show (i) Aβ40 is cleared rapidly across the BBB via low-density lipoprotein receptor-related protein (LRP)1 at a rate of 0.21 pmol/min g ISF or 6-fold faster than via the ISF flow; (ii) Aβ42 is removed across the BBB at a rate 1.9-fold slower compared with Aβ40; (iii) apoE, lipid-poor isoform 3, is cleared slowly via the ISF flow and across the BBB (0.03–0.04 pmol/min g ISF), and after lipidation its transport at the BBB becomes barely detectable within 30 mins; (iv) apoJ is eliminated rapidly across the BBB (0.16 pmol/ming ISF) via LRP2. Clearance rates of unlabeled and corresponding 125I-labeled Aβ and apolipoproteins were almost identical, but could not be measured at low physiologic levels by mass spectrometry. Amyloid β-peptide 40 binding to apoE3 reduced its efflux rate at the BBB by 5.7-fold, whereas Aβ42 binding to apoJ enhanced Aβ42 BBB clearance rate by 83%. Thus, Aβ, apoE, and apoJ are cleared from brain by different transport pathways, and apoE and apoJ may critically modify Aβ clearance at the BBB.
Photoreactivation of DNA by an Archaeal nucleoprotein Sso7d
Authors: Tashiro Ryu , Wang Andrew H.-J. , Sugiyama Hiroshi
Published: October 2006

Sso7d is a chromosomal protein of hyperthermophilic Archaea. The crystal structure of Sso7d–d(GTAAT
I
UAC)
2
has been clarified at high resolution, showing that the protein binds in the minor groove of DNA, causing a sharp kink of ≈60°. Recently, we found that photoirradiation of Sso7d and 5-iodouracil-(
I
U)-containing 5′-d(GTAAT
I
UAC)-3′ efficiently induced the abstraction of hydrogen from the methyl group of T
5
at the kink. In the present study, we found that the photoreactivity of 5-bromouracil (
Br
U)-containing 5′-d(GTAAT
Br
UAC)-3′ was enhanced in the presence of Sso7d. Using hypoxanthine (I)-containing 5′-d(ITAAT
Br
UAC)-3′, we demonstrated that electron transfer occurs efficiently from Sso7d to DNA. Product analysis showed that Trp-24 of Sso7d, located at the surface of the DNA, is consumed to produce
N′
-formylkynurenine during photoirradiation, indicating that Trp-24 acts as an electron source. To explore the possibility of electron transfer between Sso7d and other DNA substrates, we examined the photochemical repair of the thymine dimer 5′-d(GTAAT<>TAC)-3′ by Sso7d. Sso7d effectively repaired 5′-d(GTAAT<>TAC)-3′ to 5′-d(GTAATTAC)-3′ under irradiation conditions. During this reaction, Trp-24 was not oxidized significantly, indicating that the anion radical of the repaired TT sequence is oxidized by the cation radical of Trp-24, and that a so-called “circular electron transfer” mechanism is operating in this system.
An
in vitro
assay reveals a role for the diaphragm protein PV-1 in endothelial fenestra morphogenesis
Authors: Ioannidou Sofia , Deinhardt Katrin , Miotla Jadwiga , Bradley John , Cheung Eunice , Samuelsson Steven , Ng Yin-Shan , Shima David T.
Published: October 2006

Fenestrae are small pores in the endothelium of renal glomerular, gastrointestinal, and endocrine gland capillaries and are involved in the bidirectional exchange of molecules between blood and tissues. Although decades of studies have characterized fenestrae at the ultrastructural level, little is known on the mechanisms by which fenestrae form. We present the development of an
in vitro
assay in which rapid and abundant fenestra induction enables a detailed study of their biogenesis. Through the use of agents that stabilize or disassemble actin microfilaments, we show that actin microfilament remodeling is part of fenestra biogenesis in this model. Furthermore, by using a loss-of-function approach, we show that the diaphragm protein PV-1 is necessary for fenestral pore architecture and the ordered arrangement of fenestrae in sieve plates. Together, these data provide insight into the cell biology of fenestra formation and open up the future study of the fenestra to a combined morphological and biochemical analysis.
Depression induces bone loss through stimulation of the sympathetic nervous system
Authors: Yirmiya Raz , Goshen Inbal , Bajayo Alon , Kreisel Tirzah , Feldman Sharon , Tam Joseph , Trembovler Victoria , Csernus Valér , Shohami Esther , Bab Itai
Published: October 2006

Major depression is associated with low bone mass and increased incidence of osteoporotic fractures. However, causality between depression and bone loss has not been established. Here, we show that mice subjected to chronic mild stress (CMS), an established model of depression in rodents, display behavioral depression accompanied by impaired bone mass and structure, as portrayed by decreases in trabecular bone volume density, trabecular number, and trabecular connectivity density assessed in the distal femoral metaphysis and L3 vertebral body. Bone remodeling analysis revealed that the CMS-induced skeletal deficiency is accompanied by restrained bone formation resulting from reduced osteoblast number. Antidepressant therapy, which prevents the behavioral responses to CMS, completely inhibits the decrease in bone formation and markedly attenuates the CMS-induced bone loss. The depression-triggered bone loss is associated with a substantial increase in bone norepinephrine levels and can be blocked by the β-adrenergic antagonist propranolol, suggesting that the sympathetic nervous system mediates the skeletal effects of stress-induced depression. These results define a linkage among depression, excessive adrenergic activity, and reduced bone formation, thus demonstrating an interaction among behavioral responses, the brain, and the skeleton, which leads to impaired bone structure. Together with the common occurrence of depression and bone loss in the aging population, the present data implicate depression as a potential major risk factor for osteoporosis and the associated increase in fracture incidence.
Vitamin C mediates chemical aging of lens crystallins by the Maillard reaction in a humanized mouse model
Authors: Fan Xingjun , Reneker Lixing W. , Obrenovich Mark E. , Strauch Christopher , Cheng Rongzhu , Jarvis Simon M. , Ortwerth Beryl J. , Monnier Vincent M.
Published: October 2006

Senile cataracts are associated with progressive oxidation, fragmentation, cross-linking, insolubilization, and yellow pigmentation of lens crystallins. We hypothesized that the Maillard reaction, which leads browning and aroma development during the baking of foods, would occur between the lens proteins and the highly reactive oxidation products of vitamin C. To test this hypothesis, we engineered a mouse that selectively overexpresses the human vitamin C transporter SVCT2 in the lens. Consequently, lenticular levels of vitamin C and its oxidation products were 5- to 15-fold elevated, resulting in a highly compressed aging process and accelerated formation of several protein-bound advanced Maillard reaction products identical with those of aging human lens proteins. These data strongly implicate vitamin C in lens crystallin aging and may serve as a model for protein aging in other tissues particularly rich in vitamin C, such as the hippocampal neurons and the adrenal gland. The hSVCT2 mouse is expected to facilitate the search for drugs that inhibit damage by vitamin C oxidation products.
Vaccine assembly from surface proteins ofStaphylococcus aureus
Authors: Stranger-Jones Yukiko K. , Bae Taeok , Schneewind Olaf
Published: October 2006

Staphylococcus aureusis the most common cause of hospital-acquired infection. Because of the emergence of antibiotic-resistant strains, these infections represent a serious public health threat. To develop a broadly protective vaccine, we tested cell wall-anchored surface proteins ofS. aureusas antigens in a murine model of abscess formation. Immunization with four antigens (IsdA, IsdB, SdrD, and SdrE) generated significant protective immunity that correlated with the induction of opsonophagocytic antibodies. When assembled into a combined vaccine, the four surface proteins afforded high levels of protection against invasive disease or lethal challenge with human clinicalS. aureusisolates.
Endothelial cellular senescence is inhibited by nitric oxide: Implications in atherosclerosis associated with menopause and diabetes
Authors: Hayashi Toshio , Matsui-Hirai Hisako , Miyazaki-Akita Asaka , Fukatsu Akiko , Funami Jun , Ding Qun-Fang , Kamalanathan Sumitra , Hattori Yuichi , Ignarro Louis J. , Iguchi Akihisa
Published: October 2006

Senescence may contribute to the pathogenesis of atherosclerosis. Although the bioavailability of nitric oxide (NO) is limited in senescence, the effect of NO on senescence and its relationship to cardiovascular risk factors have not been investigated fully. We studied these factors by investigating senescence-associated β-galactosidase (SA-β-gal) and human telomerase activity in human umbilical venous endothelial cells (HUVECs). Treatment with NO donor (
Z
)-1-[2-(2-aminoethyl)-
N
-(2-aminoethyl)amino]diazen-1-ium-1,2-diolate (DETA-NO) and transfection with endothelial NO synthase (eNOS) into HUVECs each decreased the number of SA-β-gal positive cells and increased telomerase activity. The NOS inhibitor
N
G
-nitro-
l
-arginine methyl ester (
l
-NAME) abolished the effect of eNOS transfection. The physiological concentration of 17β-estradiol activated hTERT, decreased SA-β-gal-positive cells, and caused cell proliferation. However, ICI 182780, an estrogen receptor-specific antagonist, and
l
-NAME each inhibited these effects. Finally, we investigated the effect of NO bioavailability on high glucose-promoted cellular senescence of HUVECs. Inhibition by eNOS transfection of this cellular senescence under high glucose conditions was less pronounced. Treatment with
l
-arginine or
l
-citrulline of eNOS-transfected cells partially inhibited, and combination of
l
-arginine and
l
-citrulline with antioxidants strongly prevented, high glucose-induced cellular senescence. These data demonstrate that NO can prevent endothelial senescence, thereby contributing to the anti-senile action of estrogen. The ingestion of NO-boosting substances, including
l
-arginine,
l
-citrulline, and antioxidants, can delay endothelial senescence under high glucose. We suggest that the delay in endothelial senescence through NO and/or eNOS activation may have clinical utility in the treatment of atherosclerosis in the elderly.
Responses of IL-18- and IL-18 receptor-deficient pancreatic islets with convergence of positive and negative signals for the IL-18 receptor
Authors: Lewis Eli C. , Dinarello Charles A.
Published: October 2006

Pancreatic islets contain cells that produce IL-18 and cells that express IL-18 receptors. In experimentally induced diabetes, islet failure correlates with IL-18 levels and diabetes is delayed with blockade of endogenous IL-18. We studied islet-derived IL-18 and responses to IL-18 in a mouse model of islet allograft transplantation.In vitro, IL-18-stimulated islets produced nitric oxide, which closely matched islet apoptosis. By neutralizing IL-18 activity with IL-18 binding protein (IL-18BP), we observed that islets produce bioactive IL-18.In vivo, transgenic mice overproducing IL-18BP (IL-18BP-Tg) exhibited delayed hyperglycemia induced by β cell toxic streptozotocin. Similarly, cultured IL-18BP-Tg islets were protected from streptozotocin-induced apoptosis. In the transplant model, islets grafted from WT to IL-18BP-Tg mice achieved prolonged normoglycemia (P= 0.031). Improved graft function was also observed by using IL-18-deficient islets transplanted into WT recipients, demonstrating that endogenous, islet-derived IL-18 mediates IL-18-driven graft damage. Unexpectedly, islets from mice deficient in IL-18 receptor α chain (IL-18R) exhibited rapid graft failure (P= 0.024; IL-18- versus IL-18R-deficient grafts in WT recipients). In related studies, IL-18R-deficient splenocytes and macrophages produced 2- to 3-fold greater amounts of IL-18, TNFα, macrophage inflammatory protein 1, macrophage inflammatory protein 2, and IFNγ upon stimulation with Con A, Toll-like receptor 2 agonist, or anti-CD3 antibodies. These data reveal a role for islet-derived IL-18 activity during inflammation-mediated islet injury. Importantly, discrepancies between IL-18- and IL-18R-deficient cells suggest that IL-18Rα chain is used by an inflammation-suppressing signal.
Self-recognition in an Asian elephant
Authors: Plotnik Joshua M. , de Waal Frans B. M. , Reiss Diana
Published: October 2006

Considered an indicator of self-awareness, mirror self-recognition (MSR) has long seemed limited to humans and apes. In both phylogeny and human ontogeny, MSR is thought to correlate with higher forms of empathy and altruistic behavior. Apart from humans and apes, dolphins and elephants are also known for such capacities. After the recent discovery of MSR in dolphins (
Tursiops truncatus
), elephants thus were the next logical candidate species. We exposed three Asian elephants (
Elephas maximus
) to a large mirror to investigate their responses. Animals that possess MSR typically progress through four stages of behavior when facing a mirror: (
i
) social responses, (
ii
) physical inspection (e.g., looking behind the mirror), (
iii
) repetitive mirror-testing behavior, and (
iv
) realization of seeing themselves. Visible marks and invisible sham-marks were applied to the elephants' heads to test whether they would pass the litmus “mark test” for MSR in which an individual spontaneously uses a mirror to touch an otherwise imperceptible mark on its own body. Here, we report a successful MSR elephant study and report striking parallels in the progression of responses to mirrors among apes, dolphins, and elephants. These parallels suggest convergent cognitive evolution most likely related to complex sociality and cooperation.
Some
C. elegans
class B synthetic multivulva proteins encode a conserved LIN-35 Rb-containing complex distinct from a NuRD-like complex
Authors: Harrison Melissa M. , Ceol Craig J. , Lu Xiaowei , Horvitz H. Robert
Published: October 2006

The
Caenorhabditis elegans synthetic multivulva (synMuv) genes act redundantly to antagonize the specification of
vulval cell fates, which are promoted by an RTK/Ras pathway. At least 26 synMuv genes have been genetically identified, several of which encode proteins with homologs that act in chromatin remodeling or transcriptional repression. Here we report the molecular characterization of two synMuv genes,
lin-37
and
lin-54
. We show that
lin-37
and
lin-54
encode proteins in a complex with at least seven synMuv proteins, including LIN-35, the only
C. elegans
homolog of the mammalian tumor suppressor Rb. Biochemical analyses of mutants suggest that LIN-9, LIN-53, and LIN-54 are required for the stable formation of this complex. This complex is distinct from a second complex of synMuv proteins with a composition similar to that of the mammalian Nucleosome Remodeling and Deacetylase complex. The class B synMuv complex we identified is evolutionarily conserved and likely functions in transcriptional repression and developmental regulation.
Reproducibility of ultrasound and magnetic resonance imaging measurements of tendon size
Authors: Brushøj C. , Henriksen B. M. , Albrecht-Beste E. , Hölmich P. , Larsen K. , Bachmann Nielsen M.
Published: October 2006

Purpose: To investigate the intra- and inter-tester reproducibility of measurements of the Achilles tendon, tibialis anterior tendon, and the tibialis posterior tendon in football players using ultrasound (US) and magnetic resonance imaging (MRI).

Material and Methods: Eleven asymptomatic football players were examined. Using a standardized US scanning protocol, the tendons were examined by two observers with US for thickness, width, and cross-sectional area. One observer conducted the procedure twice. The subjects also underwent an MRI examination, and the assessment of tendon size was conducted twice by two observers.

Results: The best reproducibility judged by coefficient of variation (CV) and 95% confidence interval was determined for the Achilles tendon on both US and MRI. The variability of US on measurements on the tibialis anterior and tibialis posterior tendons was less than that when using MRI. In 12 out of 18 measurements, there were systematic differences between observers as judged by one-sided F-test.

Conclusion: The reproducibility of the three tendons was limited. Precaution should be taken when looking for minor quantitative changes, i.e., training-induced hypertrophy, and when doing so, the Achilles tendon should be used.
Pulmonary perfusion in acute pulmonary embolism: agreement of MRI and SPECT for lobar, segmental and subsegmental perfusion defects
Authors: Kluge A. , Gerriets T. , Stolz E. , Dill T. , Mueller K.-D. , Mueller C. , Bachmann G.
Published: October 2006

Purpose: To assess prospectively the agreement of magnetic resonance (MR) pulmonary perfusion with single-photon emission computed tomography (SPECT) perfusion for perfusion defects down to the subsegmental level in patients with suspected pulmonary embolism (PE).

Material and Methods: In 41 patients with suspected PE, contrast-enhanced MR pulmonary perfusion (3D-FLASH, TR/TE 1.6/0.6 ms) was compared to SPECT perfusion on a per-examination basis as well as at the lobar, segmental, and subsegmental level.

Results: The MRI protocol was completed in all patients, and mean examination time was 3 min 56 s. MR perfusion showed a very high agreement with SPECT (kappa value per examination 0.98, and 0.98, 0.83, and 0.69 for lobar, segmental, and subsegmental perfusion defects, respectively). Of 15 patients with PE, MR perfusion detected 14 cases.

Conclusion: The very high agreement of MR perfusion with SPECT perfusion enables the detection of subtle findings in suspected PE.
Imaging of primary adrenal lymphoma: case report and literature review
Authors: Zhang L. J. , Yang G. F. , Shen W. , Qi J.
Published: October 2006

Primary adrenal lymphoma is very rare, and correct preoperative diagnosis is difficult because of its nonspecific imaging findings. We report a case of bilateral primary adrenal lymphoma, with the largest dimension of 18 cm, which is the largest one reported so far, to our knowledge. Computed tomography (CT) and magnetic resonance (MR) findings were not specific enough to establish a correct diagnosis, but positron emission tomography/CT (PET/CT) showed high fluorodeoxyglucose (FDG) uptake, indicating its malignant nature. We describe the imaging findings and review the related literature to highlight this uncommon entity.
Scimitar syndrome versus meandering pulmonary vein: evaluation with three-dimensional computed tomography
Authors: Tsitouridis I. , Tsinoglou K. , Morichovitou A. , Stratilati S. , Siouggaris N. , Kontaki T.
Published: October 2006

We report two cases of abnormal configuration of the pulmonary venous system of the right lung evaluated with the use of three-dimensional spiral computed tomography (3D-CT). In the first case, an unusual form of scimitar syndrome was detected, consisting of two scimitar veins uniting into a common trunk immediately before their confluence into the inferior vena cava (IVC). The second case concerns a meandering pulmonary vein that followed a circuitous course through the right lung and came in close proximity to the IVC, before draining the entire right lung to the left atrium. In both cases, 3D-CT enabled a non-invasive, detailed anatomic evaluation of the right pulmonary vascular bed.
Magnetic resonance-guided biopsy of suspicious breast lesions with a handheld vacuum biopsy device
Authors: Gebauer B. , Bostanjoglo M. , Moesta K. T. , Schneider W. , Schlag P. M. , Felix R.
Published: October 2006

Purpose: To evaluate a handheld vacuum-assisted device system for magnetic resonance image (MRI)-guided breast lesion biopsy.

Material and Methods: In 32 patients, a total of 42 suspicious breast lesions (mean diameter 7.5 mm for mass lesions, 11.6 mm for non-masslike diffuse lesions) seen with MRI (no suspicious changes in breast ultrasound or mammography) were biopsied (27 lateral, 15 medial) using a 10G vacuum-assisted breast biopsy device under MR guidance. Histology of biopsy specimens was compared with final histology after surgery or follow-up in benign lesions.

Results: In all biopsies, technical success was achieved. Histology revealed 11 lesions with ductal carcinoma in situ (DCIS) or invasive cancer, three with intermediate lesions (LCIS) and 28 with benign breast lesions (adenosis, infected hematoma). In one patient with discordant results of MRI and histology, surgical excision revealed medullary cancer. In the follow-up (mean 18 months) of the histological benign lesions, no breast cancer development was observed. Besides minor complications (hematoma, n = 6), with no further therapeutic interventions, no complications occurred.

Conclusion: MRI-guided breast lesion biopsy using a handheld vacuum-assisted device is a safe and effective method for the work-up of suspicious lesions seen with breast MRI without changes in mammography or ultrasound. In the case of discordant histology of vacuum biopsy and breast MRI appearance, surgical excision is recommended.
Low-field magnetic resonance imaging of the lumbar spine: reliability of qualitative evaluation of disc and muscle parameters
Authors: Sorensen Solgaard J. , Kjaer P. , Jensen Secher T. , Andersen P.
Published: October 2006

Purpose: To determine the intra- and interobserver reliability in grading disc and muscle parameters using low-field magnetic resonance imaging (MRI).

Material and Methods: MRI scans of 100 subjects representative of the general population were evaluated blindly by two radiologists. Criteria for grading lumbar discs were based on the spinal nomenclature of the Combined Task Force and the literature. Consensus in rating was achieved by evaluating 50 MRI examinations in tandem. The remaining 50 examinations were evaluated independently by the observers to determine interobserver agreement and re-evaluated by one of the observers to determine intra-observer agreement.

Results: Intra- and interobserver agreement was substantial when grading changes in the lumbar discs. Interobserver agreement was fair to moderate in grading the lumbar muscles, whereas intra-observer agreement was almost perfect.

Conclusion: Convincing reliability was found in the evaluation of disc- and muscle-related MRI variables.
Autobiographical Memory Specificity Predicts Social Problem-Solving Ability in Old and Young Adults
Authors: Beaman Amanda , Pushkar Dolores , Etezadi Sarah , Bye Dorothea , Conway Michael
Published: October 2006

Based on recent research with young, depressed adults, age-related cognitive declines and decreased autobiographical specificity were hypothesized to predict poorer social problem-solving ability in older than in younger healthy adults. Priming autobiographical memory (ABM) was hypothesized to improve social problem-solving performance for older adults. Subsequent to cognitive tests, old and young participants’ specific ABMs were tested using a cued recall task, followed by a social problem-solving task. The order of the tasks was counterbalanced to test for a priming effect. Autobiographical specificity was related to cognitive ability and predicted social problem-solving ability for both age groups. However, priming of ABM did not improve social problem-solving ability for older or younger adults. This study provides support for the hypothesis that autobiographical memory serves a directive function across the life-span.
Word chunk frequencies affect the processing of pronominal object-relative clauses
Authors: Reali Florencia , Christiansen Morten H.
Published: October 2006

We present experimental support for the view that fine-grained statistical information may play a crucial role in the processing of centre-embedded linguistic structure. Using both offline and online methods, we show that the processing of pronominal object-relative clauses is influenced by the frequency of co-occurrence of the word combinations ( chunks) forming the clause. We use materials that are controlled for capacity-based factors that have been previously shown to influence comprehension of relative clauses. The results suggest that, other factors being equal, the frequency of the word chunk forming the clause affects processing difficulty. Analyses of the data indicate that the results cannot be explained by differential access to individual lexical items. Following recent constructivist approaches, we argue that frequency of co-occurrence influences the chunking mechanism by which multiword sequences may become fused into processing units that are easier to access.
The crystal structure of a Cys25 → Ala mutant of human procathepsin S elucidates enzyme–prosequence interactions
Authors: Kaulmann Guido , Palm Gottfried J. , Schilling Klaus , Hilgenfeld Rolf , Wiederanders Bernd
Published: October 2006

The crystal structure of the active‐site mutant Cys25 → Ala of glycosylated human procathepsin S is reported. It was determined by molecular replacement and refined to 2.1 Å resolution, with an R‐factor of 0.198. The overall structure is very similar to other cathepsin L‐like zymogens of the C1A clan. The peptidase unit comprises two globular domains, and a small third domain is formed by the N‐terminal part of the prosequence. It is anchored to the prosegment binding loop of the enzyme. Prosegment residues beyond the prodomain dock to the substrate binding cleft in a nonproductive orientation. Structural comparison with published data for mature cathepsin S revealed that procathepsin S residues Phe146, Phe70, and Phe211 adopt different orientations. Being part of the S1′ and S2 pockets, they may contribute to the selectivity of ligand binding. Regarding the prosequence, length, orientation and anchoring of helix α3p differ from related zymogens, thereby possibly contributing to the specificity of propeptide–enzyme interaction in the papain family. The discussion focuses on the functional importance of the most conserved residues in the prosequence for structural integrity, inhibition and folding assistance, considering scanning mutagenesis data published for procathepsin S and for its isolated propeptide.
Force field influences in β‐hairpin folding simulations
Authors: Lwin Thu Zar , Luo Ray
Published: October 2006

All‐atom force fields are now routinely used for more detailed understanding of protein folding mechanisms. However, it has been pointed out that use of all‐atom force fields does not guarantee more accurate representations of proteins; in fact, sometimes it even leads to biased structural distributions. Indeed, several issues remain to be solved in force field developments, such as accurate treatment of implicit solvation for efficient conformational sampling and proper treatment of backbone interactions for secondary structure propensities. In this study, we first investigate the quality of several recently improved backbone interaction schemes in AMBER for folding simulations of a β‐hairpin peptide, and further study their influences on the peptide's folding mechanism. Due to the significant number of simulations needed for a thorough analysis of tested force fields, the implicit Poisson‐Boltzmann solvent was used in all simulations. The chosen implicit solvent was found to be reasonable for studies of secondary structures based on a set of simulations of both α‐helical and β‐hairpin peptides with the TIP3P explicit solvent as benchmark. Replica exchange molecular dynamics was also utilized for further efficient conformational sampling. Among the tested AMBER force fields, ff03 and a revised ff99 force field were found to produce structural and thermodynamic data in comparably good agreement with the experiment. However, detailed folding pathways, such as the order of backbone hydrogen bond zipping and the existence of intermediate states, are different between the two force fields, leading to force field–dependent folding mechanisms.
Reproductive strategy and spawning activity of the European hake Merluccius merluccius (L.) in the Bay of Biscay
Authors: Murua H. , Motos L.
Published: October 2006

Histological examination of ovaries from European hake Merluccius merluccius from the Bay of Biscay sampled on a monthly basis from December 1996 to October 1997 demonstrated that European hake exhibit indeterminate fecundity. Oocyte development is asynchronous with a continuous oocyte size‐frequency distribution in prespawning, spawning and postspawning females, and a gradual decrease in the mean diameter of advanced yolked oocytes as spawning proceeds. Spawning European hake were observed throughout the 11 month study period. The spawning fraction ranged from 0·085 to 0·207, which is equivalent to a batch interval of 5–12 days. The spawning fraction and proportion of spawning females were highest from January to March. Seasonal variation of atresia was inversely related to spawning fraction. Extensive atresia in individual fish was observed in September and October, when the spawning fraction was low.
Effects of two parasites, Schistocephalus solidus (Cestoda) and Bunodera spp. (Trematoda), on the escape fast‐start performance of three‐spined sticklebacks
Authors: Blake R. W. , Kwok P. Y. L. , Chan K. H. S.
Published: October 2006

The fast‐start performance of three‐spined sticklebacks Gasterosteus aculeatus infected with Schistocephalus solidus and Bunodera spp. was determined and two distinct fast‐start responses (A and B) were observed. ‘A’ starts were of higher flexibility than B and three‐way ANOVA showed significant effects of A and B starts (P < 0·05), time (P < 0·05) and per cent standard body length, LS (P < 0·05) on the orientation angle (angle of an individual segment of the fish with respect to the direction of travel). Schistocephalus solidus infection reduced maximum velocity (P < 0·05) and maximum acceleration (P < 0·05) of infected fish. Uninfected fish and fish infected with S. solidus up to a parasite index (parasite mass divided by the sum of fish and parasite mass) of 0·1 executed both types. Infected fish exclusively executed B starts for parasite index between 0·1 and 0·2. This was not due to a reduction in body flexibility associated with mechanical obstruction caused by S. solidus as no significant difference in the ratios of body width (P > 0·05) or depth (P > 0·05) to LS were found between uninfected and infected fish. At a parasite index >0·2, infected fish were unable to perform escape fast‐starts increasing the likelihood of predation by their definitive hosts such as loons or belted kingfishers. Three‐spined sticklebacks infected with S. solidus with a parasite index of c. 0·2–0·3, however, were compromised by a suite of behavioural (e.g. increased foraging activity and amount of food consumed, increased risk associated with feeding and increased response latency to predatory stimuli), physiological (e.g. increased rate of oxygen consumption, slower growth, delayed sexual maturation and breeding success) and biomechanical (e.g. decreased fast‐start performance) factors. Bunodera spp. did not affect the escape fast‐start performance of three‐spined sticklebacks and no significant difference for maximum velocity (P > 0·05) and maximum acceleration (P > 0·05) was found.
Effects of dietary soybean meal and photoperiod cycle on osmoregulation following seawater exposure in Atlantic salmon smolts
Authors: Bakke‐McKellep A. M. , Refstie S. , Stefansson S. O. , Vanthanouvong V. , Roomans G. , Hemre G.‐I. , Krogdahl Å.
Published: October 2006

Atlantic salmon Salmo salar juveniles were fed either fishmeal‐based diets (FM) or diets in which soybean meal (SBM) partly replaced the FM from first feeding on. The fish were kept at continuous daylight during the juvenile stage. During the last 3 weeks before reaching 100 g body mass, all fish were subjected to 12L:12D. Starting at 100 g body mass, groups of 60 fish from each feeding background were subjected to continuous light for 12 weeks (short winter), or a square‐wave photoperiod cycle to stimulate parr to smolt transformation with 8L:16D during the first 6 weeks, and then continuous light during the last 6 weeks (long winter). After the 12 weeks, 20 fish from each treatment were subjected to 0, 24 or 96 h seawater exposure at a water salinity of 34. Hypo‐osmoregulatory ability at seawater exposure was assessed by mortality, intestinal pathology, plasma ion concentrations and osmolality, gill Na+/K+‐ATPase activity and element concentrations in the cytoplasm of distal intestinal enterocytes using X‐ray microanalysis. The hypo‐osmoregulatory capacity was higher in fish kept at short winter than at long winter, apparently due to more rapid development of gill Na+/K+‐ATPase activity. Fish fed SBM suffered typical soybean meal‐induced histological alterations of the distal intestine and apparent reductions in digestive function in the more proximal gastrointestinal regions. The net osmoregulatory capacity of these fish was maintained, as indicated by higher gill Na+/K+‐ATPase activity and lower plasma Na+, Ca2+ and osmolality compared to the FM‐fed fish. Thus, feeding SBM did not impair the hypo‐osmoregulatory ability of the Atlantic salmon following seawater exposure.