bluuebunny/crossref_metadata_2025 huggingface dataset:
Scattering and bound state Green’s functions on a plane via so(2,1) Lie algebra
Authors: Borges P. F. , Boschi-Filho H. , Vaidya A. N.
Published: November 2006

We calculate the Green’s functions for the particle-vortex system, for two anyons on a plane with and without a harmonic regulator and in a uniform magnetic field. These Green’s functions which describe scattering or bound states (depending on the specific potential in each case) are obtained exactly using an algebraic method related to the SO(2,1) Lie group. From these Green’s functions we obtain the corresponding wave functions and for the bound states we also find the energy spectra.
Broadband femtosecond frequency doubling in random media
Authors: Fischer R. , Saltiel S. M. , Neshev D. N. , Krolikowski W. , Kivshar Yu. S.
Published: November 2006

The authors demonstrate broadband femtosecond phase-matched noncollinear second-harmonic generation (SHG) in strontium barium niobate crystals with random ferroelectric domains. The process is similar to femtosecond SHG in ultrathin crystals, but it results in higher efficiency and exact mapping of the spectrum of the fundamental field into the spectrum of the second harmonics, even for pulses with complex spectral profiles. The observed parametric conversion process can be used as an efficient frequency mapping from infrared to visible for the femtosecond pulse monitoring.
Photo-cross-linkable light-emitting polymers for holographic patterning
Authors: Wu Lijun , Tong Woody Y. Y. , Zhong Yongchun , Wong Kam Sing , Hua Jianli , Häußler Matthias , Lam Jacky W. Y. , Tang Ben Zhong
Published: November 2006

Blue light-emitting poly(1-phenyl-1-alkyne)s containing photo-cross-linkable vinyl pendants were synthesized and photophysically characterized. Photoluminescence quantum yields are virtually unchanged for pristine and photo-cross-linked films, showing excellent stability and light-emitting property of the insoluble polymer film after photo-cross-linking process. By using laser interference lithography technique, active submicron two-dimensional photonic crystal structures have been fabricated by exposure to UV light. The obtained high quality nanostructures demonstrate that these polymers are applicable in active photonic devices such as distributed feedback laser. Furthermore, the achievable resolution of these polymers is ∼50nm, implying that these polymers may find potential applications in active nanodevices.
Electron phase modulation in a suspended InAs∕AlGaSb nanomechanical beam
Authors: Mahboob I. , Okamoto H. , Ueki M. , Yamaguchi H.
Published: November 2006

The magnetopiezoresistance in a quasi one-dimensional electron system incorporated into an InAs∕AlGaSb nanomechanical suspended beam was measured while the beam was at mechanical resonance. The magnetopiezoresistance showed reproducible highly periodic resistance oscillations which arise via strain induced electron phase modulation. The Fourier transform of the magnetopiezoresistance indicates that mechanical activation of the beam affects only a few electron trajectories and the electron interference in only a single electron loop gives rise to the resistance oscillations in the magnetopiezoresistance.
Systems approach to refining genome annotation
Authors: Reed Jennifer L. , Patel Trina R. , Chen Keri H. , Joyce Andrew R. , Applebee Margaret K. , Herring Christopher D. , Bui Olivia T. , Knight Eric M. , Fong Stephen S. , Palsson Bernhard O.
Published: November 2006

Genome-scale models of
Escherichia coli
K-12 MG1655 metabolism have been able to predict growth phenotypes in most, but not all, defined growth environments. Here we introduce the use of an optimization-based algorithm that predicts the missing reactions that are required to reconcile computation and experiment when they disagree. The computer-generated hypotheses for missing reactions were verified experimentally in five cases, leading to the functional assignment of eight ORFs (
yjjLMN, yeaTU, dctA, idnT
, and
putP
) with two new enzymatic activities and four transport functions. This study thus demonstrates the use of systems analysis to discover metabolic and transport functions and their genetic basis by a combination of experimental and computational approaches.
How many metals does it take to fix N
2
? A mechanistic overview of biological nitrogen fixation
Authors: Howard James B. , Rees Douglas C.
Published: November 2006

During the process of biological nitrogen fixation, the enzyme nitrogenase catalyzes the ATP-dependent reduction of dinitrogen to ammonia. Nitrogenase consists of two component metalloproteins, the iron (Fe) protein and the molybdenum-iron (MoFe) protein; the Fe protein mediates the coupling of ATP hydrolysis to interprotein electron transfer, whereas the active site of the MoFe protein contains the polynuclear FeMo cofactor, a species composed of seven iron atoms, one molybdenum atom, nine sulfur atoms, an interstitial light atom, and one homocitrate molecule. This Perspective provides an overview of biological nitrogen fixation and introduces three contributions to this special feature that address central aspects of the mechanism and assembly of nitrogenase.
Local field potential reflects perceptual suppression in monkey visual cortex
Authors: Wilke Melanie , Logothetis Nikos K. , Leopold David A.
Published: November 2006

Neurophysiological and functional imaging experiments remain in apparent disagreement on the role played by the earliest stages of the visual cortex in supporting a visual percept. Here, we report electrophysiological findings that shed light on this issue. We monitored neural activity in the visual cortex of monkeys as they reported their perception of a high-contrast visual stimulus that was induced to vanish completely from perception on a subset of trials. We found that the spiking of neurons in cortical areas V1 and V2 was uncorrelated with the perceptual visibility of the target, whereas that in area V4 showed significant perception-related changes. In contrast, power changes in the lower frequency bands (particularly 9–30 Hz) of the local field potential (LFP), collected on the same trials, showed consistent and sustained perceptual modulation in all three areas. In addition, for the gamma frequency range (30–50 Hz), the responses during perceptual suppression of the target were correlated significantly with the responses to its physical removal in all areas, although the modulation magnitude was considerably higher in area V4 than in V1 and V2. These results, taken together, suggest that low-frequency LFP power in early cortical processing is more closely related to the representation of stimulus visibility than is spiking or higher frequency LFP activity.
DNA nucleotide excision repair-dependent signaling to checkpoint activation
Authors: Marini Federica , Nardo Tiziana , Giannattasio Michele , Minuzzo Mario , Stefanini Miria , Plevani Paolo , Falconi Marco Muzi
Published: November 2006

Eukaryotic cells respond to a variety of DNA insults by triggering a common signal transduction cascade, known as checkpoint response, which temporarily halts cell-cycle progression. Although the main players involved in the cascade have been identified, there is still uncertainty about the nature of the structures that activate these surveillance mechanisms. To understand the role of nucleotide excision repair (NER) in checkpoint activation, we analyzed the UV-induced phosphorylation of the key checkpoint proteins Chk1 and p53, in primary fibroblasts from patients with xeroderma pigmentosum (XP), Cockayne syndrome (CS), trichothiodystrophy (TTD), or UV light-sensitive syndrome. These disorders are due to defects in transcription-coupled NER (TC-NER) and/or global genome NER (GG-NER), the NER subpathways repairing the transcribed strand of active genes or the rest of the genome, respectively. We show here that in G
0
/G
1
and G
2
/M phases of the cell cycle, triggering of the DNA damage cascade requires recognition and processing of the lesions by the GG-NER. Loss of TC-NER does not affect checkpoint activation. Mutations in
XPD
,
XPB
, and in
TTDA
, encoding subunits of the TFIIH complex, involved in both transcription and NER, impair checkpoint triggering. The only exception is represented by mutations in
XPD
, resulting in combined features of XP and CS (XP/CS) that lead to activation of the checkpoint cascade after UV radiation. Inhibition of RNA polymerase II transcription significantly reduces the phosphorylation of key checkpoint factors in XP/CS fibroblasts on exposure to UV damage.
A three-dimensional model of myxobacterial fruiting-body formation
Authors: Sozinova Olga , Jiang Yi , Kaiser Dale , Alber Mark
Published: November 2006

Myxobacterial cells are social; they swarm by gliding on surfaces as they feed cooperatively. When they sense starvation, tens of thousands of cells change their movement pattern from outward spreading to inward concentration and form aggregates that become fruiting bodies. Cells inside fruiting bodies differentiate into round, nonmotile, environmentally resistant spores. Traditionally, cell aggregation has been considered to imply chemotaxis, a long-range cell interaction that shares many features of chemical reaction–diffusion dynamics. The biological evidence, however, suggests that
Myxococcus xanthus
aggregation is the consequence of direct cell-contact interactions that are different from chemotaxis. To test whether local interactions suffice to explain the formation of fruiting bodies and the differentiation of spores within them, we have simulated the process. In this article, we present a unified 3D model that reproduces in one continuous simulation all the stages of fruiting-body formation that have been experimentally observed: nonsymmetric initial aggregates (traffic jams), streams, formation of toroidal aggregates, hemispherical 3D mounds, and finally sporulation within the fruiting body.
VEGF, a prosurvival factor, acts in concert with TGF-β1 to induce endothelial cell apoptosis
Authors: Ferrari Giovanni , Pintucci Giuseppe , Seghezzi Graziano , Hyman Kevin , Galloway Aubrey C. , Mignatti Paolo
Published: November 2006

VEGF and TGF-β1 are potent angiogenesis inducers with opposing effects on endothelial cells. TGF-β1 induces apoptosis; VEGF protects endothelial cells from apoptosis. We found that TGF-β1 promotes endothelial cell expression of FGF-2, which up-regulates VEGF synthesis. Inhibition of VEGF signaling through VEGF receptor 2 (flk-1) abrogates TGF-β1-induced apoptosis and p38
MAPK
activation. Inhibition of p38
MAPK
blocks TGF-β1-induced apoptosis, showing that VEGF/flk-1-mediated activation of p38
MAPK
is required for TGF-β1 induction of apoptosis. In the absence of TGF-β1, VEGF activates p38
MAPK
and promotes endothelial cell survival. However, in context with TGF-β1, VEGF/flk-1-mediated activation of p38
MAPK
results in apoptosis. Thus, cross-talk between TGF-β1 and VEGF signaling converts VEGF/flk-1-activated p38
MAPK
into a proapoptotic signal. This finding illustrates an unexpected role of VEGF and indicates that VEGF can be pharmacologically converted into an apoptotic factor, a novel approach to antiangiogenesis therapy.
Mullerian Inhibiting Substance enhances subclinical doses of chemotherapeutic agents to inhibit human and mouse ovarian cancer
Authors: Pieretti-Vanmarcke Rafael , Donahoe Patricia K. , Pearsall Lisa A. , Dinulescu Daniela M. , Connolly Denise C. , Halpern Elkan F. , Seiden Michael V. , MacLaughlin David T.
Published: November 2006

Mullerian Inhibiting Substance (MIS), a biological modifier that causes regression of Mullerian ducts in male embryos, is effective as a single agent
in vitro
and
in vivo
against human and mouse ovarian cancer cell lines expressing MIS type II receptor; however, little is known about how recombinant human MIS (rhMIS), now being scaled for preclinical trials, could be used in combination with cytotoxic or targeted chemotherapeutic agents. Mouse serous and endometrioid ovarian carcinoma cell lines were tested
in vitro
against rhMIS alone and with doxorubicin, paclitaxel, or cisplatin as agents in clinical use. Because MIS releases FK506 binding protein (FKBP12), which activates the mammalian target of rapamycin (mTOR) downstream of Akt, rhMIS and rapamycin combinations were tested. MIS increases p16 protein levels, and 5′-Aza-2′-deoxycytidine (AzadC) induces p16 mRNA; therefore, they were used in combination
in vitro
and
in vivo
with a human ovarian cancer cell line. A paclitaxel-resistant human ovarian cancer cell line and its parental line both respond to rhMIS
in vitro
. Additivity, synergy, or competition was observed with MIS and rapamycin, AzadC, doxorubicin, cisplatin, and paclitaxel, suggesting that MIS in combination with selective targeted therapies might achieve greater activity against ovarian cancer than the use of each individual agent alone. These assays and statistical analyses could be useful in selecting rhMIS and chemotherapeutic agent combinations that enhance clinical efficacy and reduce toxicity.
Insights on linking forests, trees, and people from the air, on the ground, and in the laboratory
Authors: Ostrom Elinor , Nagendra Harini
Published: November 2006

Governing natural resources sustainably is a continuing struggle. Major debates occur over what types of policy “interventions” best protect forests, with choices of property and land tenure systems being central issues. Herein, we provide an overview of findings from a long-term interdisciplinary, multiscale, international research program that analyzes the institutional factors affecting forests managed under a variety of tenure arrangements. This program analyzes satellite images, conducts social-ecological measurements on the ground, and tests the impact of structural variables on human decisions in experimental laboratories. Satellite images track the landscape dimensions of forest-cover change within different management regimes over time. On-the-ground social-ecological studies examine relationships between forest conditions and types of institutions. Behavioral studies under controlled laboratory conditions enhance our understanding of explicit changes in structure that affect relevant human decisions. Evidence from all three research methods challenges the presumption that a single governance arrangement will control overharvesting in all settings. When users are genuinely engaged in decisions regarding rules affecting their use, the likelihood of them following the rules and monitoring others is much greater than when an authority simply imposes rules. Our results support a frontier of research on the most effective institutional and tenure arrangements for protecting forests. They move the debate beyond the boundaries of protected areas into larger landscapes where government, community, and comanaged protected areas are embedded and help us understand when and why deforestation and regrowth occur in specific regions within these larger landscapes.
Concatenated logic gates using four coupled biocatalysts operating in series
Authors: Niazov Tamara , Baron Ronan , Katz Eugenii , Lioubashevski Oleg , Willner Itamar
Published: November 2006

The assembly of three concatenated enzyme-based logic gates consisting of OR, AND, XOR is described. Four biocatalysts, acetylcholine esterase, choline oxidase, microperoxidase-11, and the NAD
+
-dependent glucose dehydrogenase, are used to assemble the gates. Four inputs that include acetylcholine, butyrylcholine, O
2
, and glucose are used to drive the concatenated-gates system. The cofactor NAD
+
, and its reduced 1,4-dihydro form, NADH, are used as a reporter couple, and these provide an optical output for the gates. The modulus of the absorbance changes of NADH is used as a readout signal.
The 10+4 microfibril structure of thin cartilage fibrils
Authors: Holmes David F. , Kadler Karl E.
Published: November 2006

Determining the structure of cartilage collagen fibrils will provide insights into how mutations in collagen genes affect cartilage formation during skeletal morphogenesis and understanding the mechanism of fibril growth. The fibrils are indeterminate in size, heteropolymeric, and highly cross-linked, which make them refractory to analysis by conventional high-resolution structure determination techniques. Electron microscopy has been limited to making simple measurements of fibril diameter and immunolocalizing certain molecules at the fibril surface. Consequently, structural information on the fibrils is limited. In this study we have used scanning transmission electron microscopic mass mapping, analysis of axial stain exclusion pattern, and r-weighted back-projection techniques to determine the intermediate resolution (to ≈4 nm) structure of thin collagen fibrils from embryonic cartilage. The analyses show that the fibrils are constructed from a 10+4 microfibrillar arrangement in which a core of four microfibrils is surrounded by a ring of 10 microfibrils. Accurate mass measurements predict that each microfibril contains five collagen molecules in cross-section. Based on the proportion of collagen II, IX, and XI in the fibrils, the fibril core comprises two microfibrils each of collagen II and collagen XI. Single molecules of collagen IX presumably occur at the fibril surface between the extended N-terminal domains of collagen XI. The 10+4 microfibril structure explains the mechanism of diameter limitation in the narrow fibrils and the absence of narrow collagen fibrils in cartilage lacking collagen XI.
The Neoliberal Framework of EU Urban Policy in Action: Supporting Competitiveness and Reaping Disparities
Authors: Chorianopoulos Ioannis , Iosifides Theodoros
Published: November 2006

This paper concerns the gradual proliferation of the neoliberal rationale in European Union urban policies towards a specific mode of competitivenessoriented ‘policy networking’. Empirical research on the policy network of the EU URBAN Initiative in Portugal and Greece illustrates the ineffectiveness of the current approach in acknowledging the socio-economic and political specificities that influence development prospects in lagging cities. The Commission's proposals on the reform of the Funds (2007–13) suggest the incorporation of EU urban programmes in the mainstream spatial policies framework. The rationale, however, remains unchanged. The context-free emphasis put in these proposals on the ‘competitiveness’ target mitigates the ‘cohesion’ objective and risks perpetuating uneven urban development trends.
The structure of turbulent boundary layers in the wall region of plane channel flow
Authors: Alfonsi Giancarlo , Primavera Leonardo
Published: November 2006

The flow of a viscous incompressible fluid in a plane channel is simulated numerically with the use of a computational code for the numerical integration of the Navier–Stokes equations, based on a mixed spectral-finite difference technique. A turbulent-flow database representing the turbulent statistically steady state of the velocity field through 10 viscous time units is assembled at friction Reynolds number
Re

τ

=180 and the coherent structures of turbulence are extracted from the fluctuating portion of the velocity field using the proper orthogonal decomposition (POD) technique. The temporal evolution of a number of the most energetic POD modes is represented, showing the existence of dominant flow structures elongated in the streamwise direction whose shape is altered owing to the interaction with quasi-streamwise, bean-shaped turbulent-flow modes. This process of interaction is responsible for the gradual disruption of the streamwise modes of the flow.
Mother–infant bonding and the evolution of mammalian social relationships
Authors: Broad K.D , Curley J.P , Keverne E.B
Published: November 2006

A wide variety of maternal, social and sexual bonding strategies have been described across mammalian species, including humans. Many of the neural and hormonal mechanisms that underpin the formation and maintenance of these bonds demonstrate a considerable degree of evolutionary conservation across a representative range of these species. However, there is also a considerable degree of diversity in both the way these mechanisms are activated and in the behavioural responses that result. In the majority of small-brained mammals (including rodents), the formation of a maternal or partner preference bond requires individual recognition by olfactory cues, activation of neural mechanisms concerned with social reward by these cues and gender-specific hormonal priming for behavioural output. With the evolutionary increase of neocortex seen in monkeys and apes, there has been a corresponding increase in the complexity of social relationships and bonding strategies together with a significant redundancy in hormonal priming for motivated behaviour. Olfactory recognition and olfactory inputs to areas of the brain concerned with social reward are downregulated and recognition is based on integration of multimodal sensory cues requiring an expanded neocortex, particularly the association cortex. This emancipation from olfactory and hormonal determinants of bonding has been succeeded by the increased importance of social learning that is necessitated by living in a complex social world and, especially in humans, a world that is dominated by cultural inheritance.
Social buffering: relief from stress and anxiety
Authors: Kikusui Takefumi , Winslow James T , Mori Yuji
Published: November 2006

Communication is essential to members of a society not only for the expression of personal information, but also for the protection from environmental threats. Highly social mammals have a distinct characteristic: when conspecific animals are together, they show a better recovery from experiences of distress. This phenomenon, termed ‘social buffering’, has been found in rodents, birds, non-human primates and also in humans. This paper reviews classical findings on social buffering and focuses, in particular, on social buffering effects in relation to neuroendocrine stress responses. The social cues that transmit social buffering signals, the neural mechanisms of social buffering and a partner's efficacy with respect to social buffering are also detailed. Social contact appears to have a very positive influence on the psychological and the physiological aspects of social animals, including human beings. Research leading towards further understanding of the mechanisms of social buffering could provide alternative medical treatments based on the natural, individual characteristics of social animals, which could improve the quality of life.
Genomic imprinting and the social brain
Authors: Isles Anthony R , Davies William , Wilkinson Lawrence S
Published: November 2006

Genomic imprinting refers to the parent-of-origin-specific epigenetic marking of a number of genes. This epigenetic mark leads to a bias in expression between maternally and paternally inherited imprinted genes, that in some cases results in monoallelic expression from one parental allele. Genomic imprinting is often thought to have evolved as a consequence of the intragenomic conflict between the parental alleles that occurs whenever there is an asymmetry of relatedness. The two main examples of asymmetry of relatedness are when there is partiality of parental investment in offspring (as is the case for placental mammals, where there is also the possibility of extended postnatal care by one parent), and in social groups where there is a sex-biased dispersal. From this evolutionary starting point, it is predicted that, at the behavioural level, imprinted genes will influence what can broadly be termed bonding and social behaviour. We examine the animal and human literature for examples of imprinted genes mediating these behaviours, and divide them into two general classes. Firstly, mother–offspring interactions (suckling, attachment and maternal behaviours) that are predicted to occur when partiality in parental investment in early postnatal offspring occurs; and secondly, adult social interactions, when there is an asymmetry of relatedness in social groups. Finally, we return to the evolutionary theory and examine whether there is a pattern of behavioural functions mediated by imprinted genes emerging from the limited data, and also whether any tangible predictions can be made with regards to the direction of action of genes of maternal or paternal origin.
Enzymatic processing of collagen IV by MMP‐2 (gelatinase A) affects neutrophil migration and it is modulated by extracatalytic domains
Authors: Monaco Susanna , Sparano Valentina , Gioia Magda , Sbardella Diego , Di Pierro Donato , Marini Stefano , Coletta Massimo
Published: November 2006

Proteolytic degradation of basement membrane influences the cell behavior during important processes, such as inflammations, tumorigenesis, angiogenesis, and allergic diseases. In this study, we have investigated the action of gelatinase A (MMP‐2) on collagen IV, the major constituent of the basement membrane. We have compared quantitatively its action on the soluble forms of collagen IV extracted with or without pepsin (from human placenta and from Engelbreth–Holm–Swarm [EHS] murine sarcoma, respectively). The catalytic efficiency of MMP‐2 is dramatically reduced in the case of the EHS murine sarcoma with respect to the human placenta, probably due to the much tighter packing of the network which renders very slow the speed of the rate‐limiting step. We have also enquired on the role of MMP‐2 domains in processing collagen IV. Addition of the isolated collagen binding domain, corresponding to the fibronectin‐like domain of whole MMP‐2, greatly in hibits the cleavage process, demonstrating that MMP‐2 interacts with collagen type IV preferentially through its fibronectin‐like domain. Conversely, the removal of the hemopexin‐like domain, using only the catalytic domain of MMP‐2, has only a limited effect on the catalytic efficiency toward collagen IV, indicating that the missing domain does not have great relevance for the overall mechanism. Finally, we have investigated the effect of MMP‐2 proteolytic activity ex vivo. MMP‐2 action negatively affects the neutrophils' migration across type IV coated membranes and this is likely related to the production of lower molecular weight fragments that impair the cellular migration.
Dynamics of the SPRY domain–containing SOCS box protein 2: Flexibility of key functional loops
Authors: Yao Shenggen , Liu Ming S. , Masters Seth L. , Zhang Jian‐Guo , Babon Jeffrey J. , Nicola Nicos A. , Nicholson Sandra E. , Norton Raymond S.
Published: November 2006

The SPRY domain was identified originally as a sequence repeat in the dual‐specificity kinase splA and ryanodine receptors and subsequently found in many other distinct proteins, including more than 70 encoded in the human genome. It is a subdomain of the B30.2/SPRY domain and is believed to function as a protein–protein interaction module. Three‐dimensional structures of several B30.2/SPRY domain–containing proteins have been reported recently: murine SSB‐2 in solution by NMR spectroscopy, a Drosophila SSB (GUSTAVUS), and human PRYSPRY protein by X‐ray crystallography. The three structures share a core of two antiparallel β‐sheets for the B30.2/SPRY domain but show differences located mainly at one end of the β‐sandwich. Analysis of SSB‐2 residues required for interactions with its intracellular ligands has provided insights into B30.2/SPRY binding specificity and identified loop residues critical for the function of this domain. We have investigated the backbone dynamics of SSB‐2 by means of Modelfree analysis of its backbone 15N relaxation parameters and carried out coarse‐grained dynamics simulation of B30.2/SPRY domain–containing proteins using normal mode analysis. Translational self‐diffusion coefficients of SSB‐2 measured using pulsed field gradient NMR were used to confirm the monomeric state of SSB‐2 in solution. These results, together with previously reported amide exchange data, highlight the underlying flexibility of the loop regions of B30.2/SPRY domain–containing proteins that have been shown to be important for protein–protein interactions. The underlying flexibility of certain regions of the B30.2/SPRY domain–containing proteins may also contribute to some apparent structural differences observed between GUSTAVUS or PRYSPRY and SSB‐2.
Diabetes mellitus: anaesthetic management*
Authors: Robertshaw H. J. , Hall G. M.
Published: November 2006

As the incidence of diabetes mellitus continues to increase in the United Kingdom, more diabetic patients will present for both elective and emergency surgery. Whilst the underlying pathophysiology of type 1 and type 2 diabetes differs, there is much good evidence that controlling the blood glucose to > 10 mmol.l−1 in the peri‐operative period for both types of diabetic patients improves outcome. This should be achieved with a glucose–insulin–potassium regimen in all type 1 diabetics and in type 2 diabetics undergoing moderate or major surgical procedures. After surgery, a decrease in the catabolic hormone response resulting from good analgesia and the avoidance of nausea and vomiting should allow early re‐establishment of normal glycaemic control.
The anaesthetist and the cardiac catheterisation laboratory
Authors: Reddy K. , Jaggar S. , Gillbe C.
Published: November 2006

Interventional cardiology is an innovative and expanding field. Anaesthetists are increasingly involved in managing complex congenital and acquired heart lesions in the cardiac catheterisation laboratory. This article provides an overview of common lesions encountered in the cardiac catheterisation laboratory, the anaesthetic management of patients with congenital and acquired heart lesions, the procedures performed and the complications encountered during such procedures.
Continuous cervical plexus block for carotid body tumour excision in a patient with Eisenmenger's syndrome
Authors: Jones H. G. , Stoneham M. D.
Published: November 2006

A patient with Eisenmenger's syndrome presented for removal of a carotid body tumour. Continuous cervical plexus blockade was successfully used to provide peri‐operative and postoperative analgesia. The risks and benefits of regional and general anaesthesia in this high risk patient are discussed.
Expired gas backflow in oxygen delivery tubing
Authors: Coe A. J. , Wilson M. , Maithani N.
Published: November 2006

Using capnography, we investigated the backflow of expired gas into oxygen delivery tubing in 18 sedated patients receiving supplementary oxygen via a disposable facemask during spinal anaesthesia. At 5 cm from the mask, with an oxygen flow of 2 l.min−1, carbon dioxide was detected in the oxygen delivery tubing of three patients (18%) on coughing. With the patient wearing the facemask but the oxygen tubing disconnected from the oxygen source, carbon dioxide was detectable 1 m from the facemask (i.e. at the fresh gas outlet) in 14 patients. In a second group of 20 similar patients, no carbon dioxide was detected sampling at the fresh gas outlet with flows of 2 and 4 l.min−1. Assuming that detection of carbon dioxide indicates at least the possibility of contamination, oxygen tubing should be strictly single‐use in this setting. Our findings suggest that filters are not required to protect gas supply outlets, provided that the patient's facemask is removed when the fresh gas outlet is disconnected.
The effect of additional teaching on medical students' drug administration skills in a simulated emergency scenario
Authors: Degnan B. A. , Murray L. J. , Dunling C. P. , Whittlestone K. D. , Standley T. D. A. , Gupta A. K. , Wheeler D. W.
Published: November 2006

Medical students have difficulty calculating drug doses correctly, but better teaching improves their performance in written tests. We conducted a blinded, randomised, controlled trial to assess the benefit of online teaching on students' ability to administer drugs in a simulated critical incident scenario, during which they were scored on their ability to administer drugs in solution presented as a ratio (adrenaline) or percentage (lidocaine). Forty‐eight final year medical students were invited to participate; 44 (92%) attended but only nine of the 20 students (45%) directed to the extra teaching viewed it. Nevertheless, the teaching module significantly improved the students' ability to calculate the correct volume of lidocaine (p = 0.005) and adrenaline (p = 0.0002), and benefited each student's overall performance (p = 0.0007). Drug administration error is a very major problem and few interventions are known to be effective. We show that focusing on better teaching at medical school may benefit patient safety.
Rising to the challenges of achieving day surgery targets
Authors: Smith I. , Cooke T. , Jackson I. , Fitzpatrick R.
Published: November 2006

Day surgery provides high quality and efficient care for a wide variety of surgical procedures. Patients appreciate the rapid recovery and effective analgesia, while the health service benefits from a streamlined service with lower costs. Despite the numerous advantages, day surgery practices vary enormously and many patients are still denied this excellent form of care. Fundamental to improving this situation is a change in emphasis, with day surgery becoming the default option for many surgical procedures – rather than being applied selectively – with inpatient care being used only where specifically indicated. Appropriate patient preparation is facilitated by consultant‐led, nurse‐run preassessment using modern selection criteria; only conditions which will still cause problems a few hours beyond the end of the operation should be barriers to day surgery. Preassessment also provides an excellent opportunity to begin patient education and ensures that pre‐existing pathology is optimally treated. Efficient day surgery is best delivered by a specialised, dedicated, multi‐disciplinary team, but consultant anaesthetists have a major role to play in co‐ordinating policies and providing leadership. Individual anaesthetists should develop techniques that allow their patients to undergo day surgery with minimum stress, maximum comfort and the optimal chance of early discharge. Improving day surgery rates is a win–win situation, with both clinical and financial benefits.
Origin and phylogeographical structure of Chinese cattle
Authors: Lei C. Z. , Chen H. , Zhang H. C. , Cai X. , Liu R. Y. , Luo L. Y. , Wang C. F. , Zhang W. , Ge Q. L. , Zhang R. F. , Lan X. Y. , Sun W. B.
Published: November 2006

Complete mitochondrial D‐loop sequences of 231 samples were used to explore the origin and genetic diversity of Chinese cattle. Phylogenetical analysis of these sequences revealed both Bos taurus and Bos indicus mitochondrial types in Chinese cattle. Four of the previously identified mitochondrial DNA lineages (T1–T4) were identified in the Bos taurus type, including lineage T1, which was found for the first time in Chinese cattle. Two lineages (I1 and I2) were identified in the Bos indicus type. Our results support the suggestion that the Yunnan‐Guizhou Plateau is the domestication site of Chinese zebu. We also found evidence that Tibetan cattle originated from taurine and zebu cattle. The distribution pattern of Chinese cattle breeds was closely related to the geographical and climatic background. It was possible to divide Chinese cattle in this study into two major groups: northern and southern cattle.
Alterations of the ocular surface epithelial mucins 1, 2, 4 and the tear functions in patients with atopic keratoconjunctivitis
Authors: Dogru M. , Okada N. , Asano‐Kato N. , Igarashi A. , Fukagawa K. , Shimazaki J. , Tsubota K. , Fujishima H.
Published: November 2006

Background
An increased understanding of the ocular surface alterations at the cellular level in the conjunctiva and the cornea, may help explain the pathogenesis and the subsequent clinical appearance of atopic ocular allergies, which may be potentially blinding.

Purpose
To investigate MUC 1, 2 and 4 alterations, tear function and the ocular surface disorder in patients with atopic keratoconjunctivitis.

Methods
Twenty‐eight eyes of 14 atopic keratoconjunctivitis patients as well as 22 eyes of 11 age‐and sex‐matched normal subjects were studied. The subjects underwent corneal sensitivity measurements, Schirmer's test, tear film break‐up time (BUT), fluorescein and Rose Bengal staining of the ocular surface, conjunctival impression cytology and brush cytology. Impression cytology samples underwent periodic acid‐Schiff and immunohistochemical staining with MUC 1, 2 and 4 antibodies. Brush cytology specimens underwent evaluation for inflammatory cell numbers and quantitative real‐time‐PCR for MUC 1, 2 and 4 mRNA expression. Patient eyes with fluorescein and Rose Bengal scores greater than four points were regarded to have significant epithelial disease in this study.

Results
The mean corneal sensitivity and BUT values were significantly lower in atopic patients with significant epithelial disease, compared with patients with insignificant epithelial disease and controls (P<0.01). Brush cytology specimens from patients with significant epithelial disease revealed significantly higher numbers of inflammatory cells (P<0.01). Specimens from patient eyes showed positive staining for MUC 1, 2 and 4. MUC 1, 2 and 4 mRNA expressions were significantly higher in eyes with significant epithelial disease compared with eyes with insignificant epithelial disease and eyes of control subjects.

Conclusion
Ocular surface inflammation, decline in corneal sensitivity, tear film instability, changes in conjunctival epithelial MUC 1, 2 and 4 mRNA expressions were thought to be important in the pathogenesis of atopic ocular surface disease.
Reaction pattern to histamine and codeine in a human intradermal skin test model
Authors: Scherer K. , Grize L. , Schindler C. , Surber C. , Bircher A. J.
Published: November 2006

BackgroundSkin prick and intradermal skin tests (IDT) are useful tools in evaluating IgE‐mediated allergic disorders. In the literature, many variations of the techniques used are described. No general agreement exists on test procedures and reading of test results.

ObjectiveTo analyse test conditions for IDT to facilitate comparability between different study protocols.

MethodsWe tested 24 healthy volunteers with three concentrations of histamine and codeine each on the upper back, lateral upper arm and volar forearm, with/without addition of ethylene diamine tetra‐acetic acid. Reading of the resulting weal was performed by taking a digital image of the weal, later outlining the weal perimeter in triplicate and calculating the weal area using the NIH Image J software version 1.3.

ResultsWeal size was dose dependent for both substances, generally larger on the upper back than on the forearm and upper arm, and larger after codeine than after histamine. Addition of the Ca2+‐chelator ethylene diamine tetra‐acetic acid did not significantly affect weal size. Weal size induced by histamine showed better consistency than that induced by codeine.

ConclusionsThe results and our technique provide valuable tools for the daily routine as well as for the ability to compare information of intradermal tests from different studies or clinical reports. When assessing skin reactivity, we recommend the use of 1 mg/mL codeine as well as 0.1 mg/mL histamine to reflect aspects of mast‐cell releasability and of vascular reactivity. The involvement of local factors influencing the vascular reactivity or differences in opiate receptor density on mast cells surfaces needs to be addressed in future studies.
Inhibition of human allergic T‐helper type 2 immune responses by induced regulatory T cells requires the combination of interleukin‐10‐treated dendritic cells and transforming growth factor‐β for their induction
Authors: Bellinghausen I , König B , Böttcher I , Knop J , Saloga J
Published: November 2006

Background
In grass pollen‐allergic individuals, T cell anergy can be induced by IL‐10‐treated dendritic cells (IL‐10‐DC) resulting in the suppression of T helper type 1 (Th1) as well as Th2 cells. This study was performed to analyse whether such IL‐10‐DC‐treated T cells are able to act as regulatory T cells (Treg) suppressing the function of other T cells in the periphery. As transforming growth factor (TGF)‐β is also a potential inducer of Treg, we additionally analysed the inhibitory capacity of TGF‐β‐treated T cells in this system.

Materials and Methods
Freshly isolated CD4+ or CD4+CD25− T cells from grass pollen‐allergic donors were stimulated with autologous mature monocyte‐derived allergen‐pulsed DC in the presence or absence of T cells previously cultured with IL‐10‐DC‐ and/or TGF‐β.

Results
Anergic T cells induced by allergen‐pulsed IL‐10‐treated DC or allergen‐pulsed DC and TGF‐β enhanced IL‐10 production and strongly inhibited IFN‐γ production of freshly prepared peripheral CD4+ or CD4+CD25− T cells while proliferation and Th2 cytokine production were only slightly reduced. The combination of allergen‐pulsed IL‐10‐treated DC and TGF‐β had an additional effect leading to a significant suppression also of Th2 cytokine production and proliferation. Suppression was not antigen‐specific and was mainly mediated by cell‐to‐cell contact and by the molecule‐programmed death‐1 and only partially by CTLA‐4, TGF‐β and IL‐10.

Conclusion
These data demonstrate that regulatory T cells that also suppress Th2 cytokine production are induced by two signals: TGF‐β and IL‐10‐DC. This is of importance for the regulation of allergic immune responses and might be exploited for future therapeutic strategies for allergic diseases.
Repeated measurements of mite and pet allergen levels in house dust over a time period of 8 years
Authors: Antens C. J. M. , Oldenwening M. , Wolse A. , Gehring U. , Smit H. A. , Aalberse R. C. , Kerkhof M. , Gerritsen J. , De Jongste J. C. , Brunekreef B.
Published: November 2006

Background
Studies of the association between indoor allergen exposure and the development of allergic diseases have often measured allergen exposure at one point in time.

Objective
We investigated the variability of house dust mite (Der p 1, Der f 1) and cat (Fel d 1) allergen in Dutch homes over a period of 8 years.

Methods
Data were obtained in the Dutch PIAMA birth cohort study. Dust from the child's mattress, the parents' mattress and the living room floor was collected at four points in time, when the child was 3 months, 4, 6 and 8 years old. Dust samples were analysed for Der p 1, Der f 1 and Fel d 1 by sandwich enzyme immuno assay.

Results
Mite allergen concentrations for the child's mattress, the parents' mattress and the living room floor were moderately correlated between time‐points. Agreement was better for cat allergen. For Der p 1 and Der f 1 on the child's mattress, the within‐home variance was close to or smaller than the between‐home variance in most cases. For Fel d 1, the within‐home variance was almost always smaller than the between‐home variance. Results were similar for allergen levels expressed per gram of dust and allergen levels expressed per square metre of the sampled surface. Variance ratios were smaller when samples were taken at shorter time intervals than at longer time intervals.

Conclusion
Over a period of 4 years, mite and cat allergens measured in house dust are sufficiently stable to use single measurements with confidence in epidemiological studies. The within‐home variance was larger when samples were taken 8 years apart so that over such long periods, repetition of sampling is recommended.
Hormonal, pituitary magnetic resonance, LHX4 and HESX1 evaluation in patients with hypopituitarism and ectopic posterior pituitary lobe
Authors: Melo Maria Edna , Marui Suemi , Carvalho Luciani Renata , Arnhold Ivo Jorge Prado , Leite Claudia Costa , Mendonça Berenice Bilharinho , Knoepfelmacher Mirta
Published: November 2006

Objective  LHX4 and HESX1 are important in early stages of pituitary development and their mutations can be associated with an ectopic posterior lobe (EPL) in the pituitary of patients with hypopituitarism. The EPL can be located at the median eminence or at the path of the pituitary stalk. The aim of this study was to analyse LHX4 and HESX1 and characterize the hormonal deficiency profiles, establishing relationships with magnetic resonance imaging (MRI) findings in these patients.

Patients and design  Sixty‐two patients with hypopituitarism associated with EPL were submitted to evaluation of pituitary function, analysis of MRI with EPL location and molecular analysis of LHX4 and HESX1 using polymerase chain reaction (PCR), digestion with restriction enzyme and automatic sequencing.

Results  Forty‐two patients had a nonvisualized pituitary stalk (NPS), and 20 a visualized pituitary stalk (VPS). Most patients (95%) with NPS had combined pituitary hormone deficiency (CPHD), with ACTH deficiency in 85%. In patients with VPS, CPHD was found in 50% and ACTH deficiency occurred in only 20%. The frequency of the location of EPL was similar in patients with VPS and NPS: 35% at median eminence and 65% at the path of the stalk. No mutations in LHX4 and HESX1 were identified. Three new polymorphisms in LHX4 were found.

Conclusions  ACTH deficiency is frequent in patients with hypopituitarism and NPS (85%), the location of EPL at the median eminence was not predictive of the hormonal profile [isolated GH deficiency (IGHD) or CPHD], and LHX4 and HESX1 genes mutations remain rare causes of hypopituitarism associated with EPL.
Cortisol secretary pattern and glucocorticoid feedback sensitivity in women from a Mediterranean area: relationship with anthropometric characteristics, dietary intake and plasma fatty acid profile
Authors: García‐Prieto M. D. , Tébar F. J. , Nicolás F. , Larqué E. , Zamora S. , Garaulet M.
Published: November 2006

Background  Chronic stress is associated with a dysfunctional hypothalamic‐pituitary‐adrenal (HPA) axis consisting on disturbances on the cortisol response and lipid metabolism.

Objective  To evaluate the HPA axis activity in women from a Mediterranean area, comparing three different measurements: daily cortisol secretory variability, postprandial cortisol secretion and glucocorticoid feedback sensitivity. In addition, HPA axis disturbance is correlated with dietary habits and plasma fatty acid profiles.

Design  The participants were 41 women born during the first 6 months of 1960 and living in a Mediterranean area (Murcia, Spain). They were of normal weight, with a waist circumference of 80·5 ± 9·3 cm. Their salivary cortisol levels, 7‐day dietary record and plasma fatty acid profile were evaluated. Daily cortisol variability and postlunch cortisol secretion were recorded and a dexamethasone suppression test is performed in order to detect possible HPA disturbance.

Results  Both the methods used for HPA axis evaluation were positively correlated (r = 0·448, P = 0·004). Subjects with normal diurnal curves (high cortisol variability) showed significantly higher cortisol values in the morning and postprandial cortisol secretion than women with pathological curves (medium and low variability). Cortisol variability was inversely correlated with waist circumference (r = –0·312, P = 0·047), suggesting that a disturbed HPA axis response may lead to an android pattern of body fat distribution. Dietary fat and saturated fatty acid intake were lower in the high cortisol variability group, while monounsaturated fatty acid intake was higher (P < 0·05). No major differences were reported in plasma fatty acid profile.

Conclusions  A disturbed HPA axis is associated with abdominal fat distribution and a higher content of fat and saturated fatty acids in the diet. Women who chose a dietary pattern closer to the Mediterranean diet, with high monounsaturated fatty acid intake, showed lower levels on HPA axis disturbance.