bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental and theoretical study of the reaction of POCl3− with O2
Authors: Kerkines Ioannis S. K. , Morokuma Keiji , Iordanova Nedialka , Viggiano A. A.
Published: January 2010

The oxidation of the trichlorooxyphosphorus anion (POCl3−), which takes place in combustion flames, has been examined experimentally at a variety of temperatures and theoretically via ab initio and density functional methods. The reaction was examined in a turbulent ion flow tube and kinetics was measured between 300 and 626 K, estimating an overall reaction barrier of 1.23 kcal/mol. Calculations at the density functional, Møller–Plesset second order perturbation, and coupled cluster levels of theory with basis sets up to augmented triple-ζ quality point to a multistep reaction mechanism involving an initial [OP(Cl)3(OO)]− intermediate, an adduct between triplet O2 with POCl3−, subsequent formation of a four-membered nonplanar POOCl ring transition state, with concomitant breaking of the PCl and OO bonds to provide a transient intermediate [OP(Cl)2OO⋯Cl]−, which, in turn, converts to the product complex (POCl2−)(ClO) upon formation of the ClO bond without barrier. The calculated energy of the four-membered transition state is considered to be in good agreement with the small overall barrier found by experiment. The final step is responsible for the large exothermicity of the reaction.
Crossed-beam studies of electron transfer to oriented trichloronitromethane, CCl3NO2, molecules
Authors: Harland Peter W. , Brooks Philip R.
Published: January 2010

Fast potassium atoms donate an electron to CCl3NO2 molecules to form K+ ions and the negative ions O−, Cl−, NO2−, CCl3−, CCl2NO2−, CCl3NO−, and CCl3NO2−. Threshold energies are measured for these ions and electron affinities for CCl2NO2−, CCl3NO−, and CCl3NO2− are estimated to be 2.35, 2.35, and 1.89 eV (±0.6 eV), respectively. The threshold energies show that the C–N and N–O bonds are substantially weaker than in nitromethane. The CCl3NO2 molecules are oriented before the collision and at energies near 2.5 eV the electron appears to transfer to the π∗NO orbital forming the parent negative ion, CCl3NO2−, which is stabilized by interacting with the K+ donor. As the collision energy increases the parent negative ion fragments and the orientation dependence of the fragment ions helps understand the fragmentation pathway.
A quasiclassical trajectory study of the OH+SO reaction: The role of rotational energy
Authors: Ballester M. Y. , Orozco-Gonzalez Y. , Garrido J. D. , Dos Santos H. F.
Published: January 2010

A full dimensional quasiclassical trajectory study of the OH+SO reaction is presented with the aim of investigating the role of the reactants rotational energy in the reactivity. Different energetic combinations with one and both reactants rotationally excited are studied. A passive method is used to correct zero-point-energy leakage in the classical calculations. The reactive cross sections, for each combination, are calculated and fitted to a capturelike model combined with a factor accounting for recrossing effects. Reactivity decreases as rotational energy is increased in any of both reactants. This fact provides a theoretical support for the experimental dependence of the rate constant on temperature.
The Queer Intimacy of Global Vision: Documentary Practice and the AIDS Pandemic
Authors: Raimondo Meredith
Published: January 2010

This paper examines the visual and narrative geographies of AIDS in the documentaries Pandemic and A Closer Walk (both of which came out in 2003). Each film offers a travelogue of diverse sites affected by HIV/AIDS in order to politicize viewers' understanding of their place in the global pandemic, seeking to remake the spatial subjectivities that support a dangerously disinterested status quo that allows preventable illness and death to occur. In exploring the spatial politics of mass-mediated subject formation through these conventionally accessible documentaries, I argue that each film hopes to offer what I will call a ‘queer optic’ on global AIDS, enabling viewers to look critically at the structures of inequality that normalize preventable suffering. By challenging normative ways of looking at AIDS, these documentaries seek to produce visual intimacies with the hope of diminishing the distinterest of distance. However, neither film is able to realize its boldest ambitions. While recognizing their strong commitment to greater justice for people living with HIV/AIDS, I argue that each film employs narrative and visual strategies that ultimately limit their efficacy as political projects. In various ways, they struggle with and in substantive ways fail to dislodge colonial narratives and optics. By examining their projects through a theoretical framework influenced by early AIDS video activism, I demonstrate the importance of identifying visual strategies that resist neoimperial logics that too often shape the representation of spatial Others.
Towards a Politics of Mobility
Authors: Cresswell Tim
Published: January 2010

This paper proposes an approach to mobility that takes both historical mobilities and forms of immobility seriously. It is argued that is important for the development of a politics of mobility. To do this it suggests that mobility can be thought of as an entanglement of movement, representation, and practice. Following this it argues for a more finely developed politics of mobility that thinks below the level of mobility and immobility in terms of motive force, speed, rhythm, route, experience, and friction. Finally, it outlines a notion of ‘constellations of mobility’ that entails considering the historical existence of fragile senses of movement, meaning, and practice marked by distinct forms of mobile politics and regulation.
Nuclear factor-κB is a critical mediator of stress-impaired neurogenesis and depressive behavior
Authors: Koo Ja Wook , Russo Scott J. , Ferguson Deveroux , Nestler Eric J. , Duman Ronald S.
Published: January 2010

Proinflammatory cytokines, such as IL-1β, have been implicated in the cellular and behavioral effects of stress and in mood disorders, although the downstream signaling pathways underlying these effects have not been determined. In the present study, we demonstrate a critical role for NF-κB signaling in the actions of IL-1β and stress. Stress inhibition of neurogenesis in the adult hippocampus, which has been implicated in the prodepressive effects of stress, is blocked by administration of an inhibitor of NF-κB. Further analysis reveals that stress activates NF-κB signaling and decreases proliferation of neural stem-like cells but not early neural progenitor cells in the adult hippocampus. We also find that depressive-like behaviors caused by exposure to chronic stress are mediated by NF-κB signaling. Together, these data identify NF-κB signaling as a critical mediator of the antineurogenic and behavioral actions of stress and suggest previously undescribed therapeutical targets for depression.
Chemoresponsive assemblies of microparticles at liquid crystalline interfaces
Authors: Koenig Gary M. , Lin I-Hsin , Abbott Nicholas L.
Published: January 2010

Assemblies formed by solid particles at interfaces have been widely studied because they serve as models of molecular phenomena, including molecular self-assembly. Solid particles adsorbed at interfaces also provide a means of stabilizing liquid–liquid emulsions and synthesizing materials with tunable mechanical, optical, or electronic properties. Whereas many past studies have investigated colloids at interfaces of isotropic liquids, recently, new types of intercolloidal interactions have been unmasked at interfaces of liquid crystals (LCs): The long-range ordering of the LCs, as well as defects within the LCs, mediates intercolloidal interactions with symmetries that differ from those observed with isotropic liquids. Herein, we report the decoration of interfaces formed between aqueous phases and nematic LCs with prescribed densities of solid, micrometer-sized particles. The microparticles assemble into chains with controlled interparticle spacing, consistent with the dipolar symmetry of the defects observed to form about each microparticle. Addition of a molecular surfactant to the aqueous phase results in a continuous ordering transition in the LC, which triggers reorganization of the microparticles, first by increasing the spacing between microparticles within chains and ultimately by forming two-dimensional arrays with local hexagonal symmetry. The ordering transition of the microparticles is reversible and is driven by surfactant-induced changes in the symmetry of the topological defects induced by the microparticles. These results demonstrate that the orderings of solid microparticles and molecular adsorbates are strongly coupled at the interfaces of LCs and that LCs offer the basis of methods for reversible, chemosensitive control of the interfacial organization of solid microparticles.
Arabidopsis V-ATPase activity at the tonoplast is required for efficient nutrient storage but not for sodium accumulation
Authors: Krebs Melanie , Beyhl Diana , Görlich Esther , Al-Rasheid Khaled A. S. , Marten Irene , Stierhof York-Dieter , Hedrich Rainer , Schumacher Karin
Published: January 2010

The productivity of higher plants as a major source of food and energy is linked to their ability to buffer changes in the concentrations of essential and toxic ions. Transport across the tonoplast is energized by two proton pumps, the vacuolar H
+
-ATPase (V-ATPase) and the vacuolar H
+
-pyrophosphatase (V-PPase); however, their functional relation and relative contributions to ion storage and detoxification are unclear. We have identified an Arabidopsis mutant in which energization of vacuolar transport solely relies on the activity of the V-PPase. The
vha-a2 vha-a3
double mutant, which lacks the two tonoplast-localized isoforms of the membrane-integral V-ATPase subunit VHA-a, is viable but shows day-length-dependent growth retardation. Nitrate content is reduced whereas nitrate assimilation is increased in the
vha-a2 vha-a3
mutant, indicating that vacuolar nitrate storage represents a major growth-limiting factor. Zinc is an essential micronutrient that is toxic at excess concentrations and is detoxified via a vacuolar Zn
2+
/H
+
-antiport system. Accordingly, the double mutant shows reduced zinc tolerance. In the same way the vacuolar Na
+
/H
+
-antiport system is assumed to be an important component of the system that removes sodium from the cytosol. Unexpectedly, salt tolerance and accumulation are not affected in the
vha-a2 vha-a3
double mutant. In contrast, reduction of V-ATPase activity in the trans-Golgi network/early endosome (TGN/EE) leads to increased salt sensitivity. Taken together, our results show that during gametophyte and embryo development V-PPase activity at the tonoplast is sufficient whereas tonoplast V-ATPase activity is limiting for nutrient storage but not for sodium tolerance during vegetative and reproductive growth.
Asymmetric receptor contact is required for tyrosine autophosphorylation of fibroblast growth factor receptor in living cells
Authors: Bae Jae Hyun , Boggon Titus J. , Tomé Francisco , Mandiyan Valsan , Lax Irit , Schlessinger Joseph
Published: January 2010

Tyrosine autophosphorylation of receptor tyrosine kinases plays a critical role in regulation of kinase activity and in recruitment and activation of intracellular signaling pathways. Autophosphorylation is mediated by a sequential and precisely ordered intermolecular (trans) reaction. In this report we present structural and biochemical experiments demonstrating that formation of an asymmetric dimer between activated FGFR1 kinase domains is required for transphosphorylation of FGFR1 in FGF-stimulated cells. Transphosphorylation is mediated by specific asymmetric contacts between the N-lobe of one kinase molecule, which serves as an active enzyme, and specific docking sites on the C-lobe of a second kinase molecule, which serves a substrate. Pathological loss-of-function mutations or oncogenic activating mutations in this interface may hinder or facilitate asymmetric dimer formation and transphosphorylation, respectively. The experiments presented in this report provide the molecular basis underlying the control of transphosphorylation of FGF receptors and other receptor tyrosine kinases.
Aspartate racemase, generating neuronal D-aspartate, regulates adult neurogenesis
Authors: Kim Paul M. , Duan Xin , Huang Alex S. , Liu Cindy Y. , Ming Guo-li , Song Hongjun , Snyder Solomon H.
Published: January 2010

D-Aspartic acid is abundant in the developing brain. We have identified and cloned mammalian aspartate racemase (DR), which converts L-aspartate to D-aspartate and colocalizes with D-aspartate in the brain and neuroendocrine tissues. Depletion of DR by retrovirus-mediated expression of short-hairpin RNA in newborn neurons of the adult hippocampus elicits profound defects in the dendritic development and survival of newborn neurons and survival. Because D-aspartate is a potential endogenous ligand for NMDA receptors, the loss of which elicits a phenotype resembling DR depletion, D-aspartate may function as a modulator of adult neurogenesis.
Ultrafast solvation dynamics at binding and active sites of photolyases
Authors: Chang Chih-Wei , Guo Lijun , Kao Ya-Ting , Li Jiang , Tan Chuang , Li Tanping , Saxena Chaitanya , Liu Zheyun , Wang Lijuan , Sancar Aziz , Zhong Dongping
Published: January 2010

Dynamic solvation at binding and active sites is critical to protein recognition and enzyme catalysis. We report here the complete characterization of ultrafast solvation dynamics at the recognition site of photoantenna molecule and at the active site of cofactor/substrate in enzyme photolyase by examining femtosecond-resolved fluorescence dynamics and the entire emission spectra. With direct use of intrinsic antenna and cofactor chromophores, we observed the local environment relaxation on the time scales from a few picoseconds to nearly a nanosecond. Unlike conventional solvation where the Stokes shift is apparent, we observed obvious spectral shape changes with the minor, small, and large spectral shifts in three function sites. These emission profile changes directly reflect the modulation of chromophore’s excited states by locally constrained protein and trapped-water collective motions. Such heterogeneous dynamics continuously tune local configurations to optimize photolyase’s function through resonance energy transfer from the antenna to the cofactor for energy efficiency and then electron transfer between the cofactor and the substrate for repair of damaged DNA. Such unusual solvation and synergetic dynamics should be general in function sites of proteins.
Active Fault-Tolerant Quantum Error Correction: The Curse of the Open System
Authors: Hagar Amit
Published: January 2010

Relying on the universality of quantum mechanics and on recent results known as the “threshold theorems,” quantum information scientists deem the question of the feasibility of large-scale, fault-tolerant, and computationally superior quantum computers as purely technological. Reconstructing this question in statistical mechanical terms, this article suggests otherwise by questioning the physical significance of the threshold theorems. The skepticism it advances is neither too strong (hence is consistent with the universality of quantum mechanics) nor too weak (hence is independent of technological contingencies).
Coadministration of Propofol and Remifentanil for Lumbar Puncture in Children
Authors: Hayes Jason A. , Lopez Alejandra V. , Pehora Carolyne M. , Robertson James M. , Abla Oussama , Crawford Mark W.
Published: January 2010

Background

The combination of propofol and remifentanil may be particularly suitable for short-duration procedures such as lumbar puncture. The authors undertook a two-part study to evaluate coadministration of propofol and remifentanil as an anesthetic technique for lumbar puncture in children.

Methods

The first part was a sequential allocation dose-finding study to determine the minimum effective dose of remifentanil when coadministered with 2.0 or 4.0 mg/kg propofol. The second was a randomized double-blind study to compare the intraoperative and recovery characteristics of 2.0 or 4.0 mg/kg propofol coadministered with the corresponding effective dose of remifentanil.

Results

Effective doses of remifentanil in 98% of children were 1.50 +/- 1.00 and 0.52 +/- 1.06 microg/kg when coadministered with 2.0 and 4.0 mg/kg propofol, respectively. The duration of apnea was longer (median, 110 vs. 73 s; P < 0.05) and the time to awakening was shorter (median, 10 vs. 23 min; P < 0.05) after 2.0 mg/kg propofol plus 1.5 microg/kg remifentanil compared with 4.0 mg/kg propofol plus 0.5 microg/kg remifentanil. No child experienced hypotension or postprocedure nausea or vomiting after either dose combination.

Conclusions

Both dose combinations (2.0 mg/kg propofol plus 1.5 microg/kg remifentanil and 4.0 mg/kg propofol plus 0.5 microg/kg remifentanil) provide effective anesthesia for lumbar puncture in children. However, the intraoperative and recovery characteristics of the two dose combinations differ in that the duration of apnea increases whereas recovery time decreases as the dose of remifentanil is increased and that of propofol is decreased.
Dexmedetomidine Weakens Dynamic Cerebral Autoregulation as Assessed by Transfer Function Analysis and the Thigh Cuff Method
Authors: Ogawa Yojiro , Iwasaki Ken-ichi , Aoki Ken , Kojima Wakako , Kato Jitsu , Ogawa Setsuro
Published: January 2010

Background

Dexmedetomidine, which is often used in intensive care units in patients with compromised circulation, might induce further severe decreases in cerebral blood flow (CBF) with temporal decreases in arterial pressure induced by various stimuli if dynamic cerebral autoregulation is not improved. Therefore, the authors hypothesized that dexmedetomidine strengthens dynamic cerebral autoregulation.

Methods

Fourteen healthy male subjects received placebo, low-dose dexmedetomidine (loading, 3 microg x kg(-1) x h(-1) for 10 min; maintenance, 0.2 microg x kg(-1) x h(-1) for 60 min), and high-dose dexmedetomidine (loading, 6 microg x kg(-1) x h(-1) for 10 min; maintenance, 0.4 microg x kg(-1) x h(-1) for 60 min) infusions in a randomized, double-blind, crossover study. After 70 min of drug administration, dynamic cerebral autoregulation was estimated by transfer function analysis between arterial pressure variability and CBF velocity variability, and the thigh cuff method.

Results

Compared with placebo, steady state CBF velocity and mean blood pressure significantly decreased during administration of dexmedetomidine. Transfer function gain in the very-low-frequency range increased and phase in the low-frequency range decreased significantly, suggesting alterations in dynamic cerebral autoregulation in lower frequency ranges. Moreover, the dynamic rate of regulation and percentage restoration in CBF velocity significantly decreased when a temporal decrease in arterial pressure was induced by thigh cuff release.

Conclusion

Contrary to the authors' hypothesis, the current results of two experimental analyses suggest together that dexmedetomidine weakens dynamic cerebral autoregulation and delays restoration in CBF velocity during conditions of decreased steady state CBF velocity. Therefore, dexmedetomidine may lead to further sustained reductions in CBF during temporal decreases in arterial pressure.
Lumbar Plexus Block Using High-pressure Injection Leads to Contralateral and Epidural Spread
Authors: Gadsden Jeff C. , Lindenmuth Danielle M. , Hadzic Admir , Xu Daquan , Somasundarum Lakshmanasamy , Flisinski Kamil A.
Published: January 2010

Background

The main advantage of lumbar plexus block over neuraxial anesthesia is unilateral blockade; however, the relatively common occurrence of bilateral spread (up to 27%) makes this advantage unpredictable. The authors hypothesized that high injection pressures during lumbar plexus block carry a higher risk of bilateral or neuraxial anesthesia.

Methods

Eighty patients undergoing knee arthroscopy (age 18-65 yr; American Society of Anesthesiologists physical status I or II) during a standard, nerve stimulator-guided lumbar plexus block using 35 ml mepivacaine, 1.5%, were scheduled to be studied. Patients were randomly assigned to receive either a low-pressure (< 15 psi) or a high-pressure (> 20 psi) injection, as assessed by an inline injection pressure monitor (BSmart; Concert Medical LLC, Norwell, MA). The block success rate and the presence of bilateral sensory and/or motor blockade were assessed.

Results

An interim analysis was performed at n = 20 after an unexpectedly high number of patients had neuraxial spread, necessitating early termination of the study. Five of 10 patients (50%) in the high-pressure group had a neuraxial block with a dermatomal sensory level T10 or higher. In contrast, no patient in the low-pressure group (n = 10) had evidence of neuraxial spread. Moreover, 6 patients (60%) in the high-pressure group demonstrated bilateral sensory blockade in the femoral distribution, whereas no patient in the low-pressure group had evidence of a bilateral femoral block.

Conclusions

Injection of local anesthetic with high injection pressure (> 20 psi) during lumbar plexus block commonly results in unwanted bilateral blockade and is associated with high risk of neuraxial blockade.
Differential Effect of Morphine and Morphine-6-glucuronide on the Control of Breathing in the Anesthetized Cat
Authors: Teppema Luc J. , van Dorp Eveline , Gourabi Babak Mousavi , van Kleef Jack W. , Dahan Albert
Published: January 2010

Background

Morphine's metabolite, morphine-6-glucuronide (M6G), activates the mu-opioid receptor. Previous data suggest that M6G activates a unique M6G receptor that is selectively antagonized by 3-methoxynaltrexome (3mNTX). The authors compared the effects of M6G and morphine on breathing in the anesthetized cat and assessed whether 3mNTX reversal was selective for M6G.

Methods

Step changes in end-tidal carbon dioxide concentration were applied in cats anesthetized with alpha-chloralose-urethane. In study 1, the effect of the 0.15 mg/kg morphine followed by 0.2 mg/kg 3mNTX and next 0.8 mg/kg M6G was assessed in six cats. In study 2, the effect of 0.8 mg/kg M6G followed by 0.2 mg/kg 3mNTX and 0.15 mg/kg morphine was tested in another six cats. The ventilatory carbon dioxide responses were analyzed with a two-compartment model of the ventilatory controller, which consists of a fast peripheral and a slow central component.

Results

Both opioids shifted the ventilatory carbon dioxide responses to higher end-tidal carbon dioxide levels. Morphine had a preferential depressant effect within the central chemoreflex loop. In contrast, M6G had a preferential depressant effect within the peripheral chemoreflex loop. Irrespective of the opioid, 3mNTX caused full reversal of and prevented respiratory depression.

Conclusions

In anesthetized cats, the mu-opioids morphine and M6G induce respiratory depression at different sites within the ventilatory control system. Because 3mNTX caused full reversal of the respiratory depressant effects of both opioids, it is unlikely that a 3mNTX-sensitive unique M6G receptor is the cause of the differential respiratory behavior of morphine and M6G.
Time and Cardiac Risk of Surgery after Bare-metal Stent Percutaneous Coronary Intervention
Authors: Nuttall Gregory A. , Brown Michael J. , Stombaugh John W. , Michon Peter B. , Hathaway Matthew F. , Lindeen Kevin C. , Hanson Andrew C. , Schroeder Darrell R. , Oliver William C. , Holmes David R. , Rihal Charanjit S.
Published: January 2010

Background

The duration of time that elective noncardiac surgery (NCS) should be delayed after percutaneous coronary intervention (PCI) with bare metal stents (BMSs) is unknown.

Methods

This large, single-center, retrospective study examined the relation between complication rate in patients with BMSs undergoing NCS and the duration of time between PCI and NCS. Primary endpoints included in-hospital major adverse cardiac events (death, myocardial infarction, stent thrombosis, or repeat revascularization with either coronary artery bypass grafting or PCI of the target vessel) and bleeding events. The relation between the events and the timing of noncardiac surgery after PCI with BMS was assessed using univariate analysis and multiple logistic regression.

Results

From January 1, 1990, to January 1, 2005, a total of 899 patients were identified. The frequency of major adverse cardiac events was 10.5% when NCS was performed less than 30 days after PCI with BMS, 3.8% when NCS was performed between 31 and 90 days after PCI with BMS, and 2.8% when NCS was performed more than 90 days after PCI with BMS. In univariate and multivariate analyses, a shorter time interval between PCI with BMS and noncardiac surgery was significantly associated with increased incidence of major adverse cardiac events (univariate: P < 0.001; odds ratio = 4.0; 95% confidence interval, 2.0-8.3; multivariate: P = 0.006; odds ratio = 3.2; 95% confidence interval, 1.5-6.9). Bleeding events were not associated with time between PCI with BMS and NCS or with the use of antiplatelet therapy in the week before NCS.

Conclusions

The incidence of major adverse cardiac events is lowest when NCS is performed at least 90 days after PCI with BMS.
Cardiac Risk of Noncardiac Surgery after Percutaneous Coronary Intervention with Drug-eluting Stents
Authors: Rabbitts Jennifer A. , Nuttall Gregory A. , Brown Michael J. , Hanson Andrew C. , Oliver William C. , Holmes David R. , Rihal Charanjit S.
Published: January 2010

Background

The American College of Cardiology released a scientific advisory that included a recommendation to delay elective of noncardiac surgery (NCS) for 1 yr after percutaneous coronary intervention (PCI) with a drug-eluting stent (DES).

Methods

This single-center, retrospective study examined the risk for complications of NCS performed within 2 yr after DES placement and examined whether this risk changed based on the time between procedures. The primary endpoint was major adverse cardiac events (MACEs) during the hospitalization for NCS. Bleeding events were analyzed as a secondary endpoint.

Results

From April 22, 2003, to December 31, 2006, a total of 520 patients underwent NCS within 2 yr after PCI with a DES at Mayo Clinic. The majority, 84%, of the DES placed were Cypher stents. The frequency of MACE was not found to be significantly associated with the time between PCI and NCS (rate of MACEs 6.4, 5.7, 5.9, and 3.3% at 0-90, 91-180, 181-365, and 366-730 days after PCI with DES, respectively; P = 0.727 for comparison across groups). Characteristics found to be associated with MACEs in univariate analysis were advanced age (P = 0.031), emergent NCS (P = 0.006), shock at time of PCI (P = 0.035), previous history of myocardial infarction (P = 0.046), and continuation of a thienopyridine (ticlopidine or clopidogrel) into the preoperative period (P = 0.040). The rate of transfusion did not seem to be associated with antiplatelet therapy use.

Conclusions

The risk of MACEs with NCS after DES placement was not significantly associated with time from stenting to surgery, but observed rates of MACEs were lowest after 1 yr.
Effect of Progressive Mandibular Advancement on Pharyngeal Airway Size in Anesthetized Adults
Authors: Kuna Samuel T. , Woodson Lee C. , Solanki Daneshvari R. , Esch Oliver , Frantz Donald E. , Mathru Mali
Published: January 2010

Background

General anesthesia in adult humans is associated with narrowing or complete closure of the pharyngeal airway. The purpose of this study was to determine the effect of progressive mandibular advancement on pharyngeal airway size in normal adults during intravenous infusion of propofol for anesthesia.

Methods

Magnetic resonance imaging was performed in nine normal adults during wakefulness and during propofol anesthesia. A commercially available intraoral appliance was used to manually advance the mandible. Images were obtained during wakefulness without the appliance and during anesthesia with the participants wearing the appliance under three conditions: without mandibular advancement, advancement to 50% maximum voluntary advancement, and maximum advancement. Using computer software, airway area and maximum anteroposterior and lateral airway diameters were measured on the axial images at the level of the soft palate, uvula, tip of the epiglottis, and base of the epiglottis.

Results

Airway area across all four airway levels decreased during anesthesia without mandibular advancement compared with airway area during wakefulness (P < 0.007). Across all levels, airway area at 50% advancement during anesthesia was less than that at centric occlusion during wakefulness (P = 0.06), but airway area with maximum advancement during anesthesia was similar to that during wakefulness (P = 0.64). In general, anteroposterior and lateral airway diameters during anesthesia without mandibular advancement were decreased compared with wakefulness and were restored to their wakefulness values with 50% and/or maximal advancement.

Conclusions

Maximum mandibular advancement during propofol anesthesia is required to restore the pharyngeal airway to its size during wakefulness in normal adults.
Brief alcohol intervention—where to from here? Challenges remain for research and practice
Authors: Nilsen Per
Published: January 2010

Brief intervention (BI) is intended as an early intervention for non‐treatment‐seeking, non‐alcohol‐dependent, hazardous and harmful drinkers. This text provides a brief summary of key BI research findings from the last three decades and discusses a number of knowledge gaps that need to be addressed. Five areas are described: patient intervention efficacy and effectiveness; barriers to BI implementation by health professionals; individual‐level factors that impact on BI implementation; organization‐level factors that impact on BI implementation; and society‐level factors that impact on BI implementation. BI research has focused largely upon the individual patient and health professional levels, with the main focus upon primary health care research, and studies are lacking in other settings. However, research must, to a larger degree, take into account the organizational and wider context in which BI occurs, as well as interaction between factors at different levels, in order to advance the understanding of how wider implementation of BI can be achieved in various settings and how different population groups can be reached. It is also important to expand BI research beyond its current parameters to investigate more ambitious long‐term educational programmes and new organizational models. More widespread implementation of BI will require many different interventions (efforts, actions, initiatives, etc.) at different interlinked levels, from implementation interventions targeting individual health professionals' knowledge, skills, attitudes and behaviours concerning alcohol issues, BI and behaviour change counselling to efforts at the organizational and societal levels that influence the conditions for delivering BI as part of routine health care.
Pyloric gland metaplasia and pouchitis in patients with ileal pouch‐anal anastomoses
Authors: KARIV R. , PLESEC T. P. , GAFFNEY K. , LIAN L. , FAZIO V. W. , REMZI F. H. , LOPEZ R. , GOLDBLUM J. R. , SHEN B.
Published: January 2010

Aliment Pharmacol Ther 31, 862–873

Background  Diagnosis and management of chronic antibiotic‐refractory pouchitis and Crohn’s disease of the pouch can be challenging. Pyloric gland metaplasia is a histological feature indicative of chronic mucosal inflammation. Its value in diagnosis and prognosis of pouch disorders has not been investigated.

Aim  To assess the prevalence, diagnostic and prognostic value, and risk factors of pyloric gland metaplasia in pouch patients.

Methods  Patients were identified from our prospectively maintained Pouchitis Database. Pouch biopsy specimens were re‐reviewed for pyloric gland metaplasia and other histological features. Two cohorts of patients were studied: a historical cohort (n = 111) and the second, a validation cohort (n = 100). Univariate and multivariate analyses were performed to assess risk factors for pyloric gland metaplasia.

Results  The prevalence of pyloric gland metaplasia in the historical cohort and validation cohort was 45 (40.1%) and 24 (24.0%), respectively. The sensitivity and specificity of pyloric gland metaplasia for the diagnosis of chronic antibiotic‐refractory pouchitis or Crohn’s disease were 70.7% and 92.5%, respectively, for the first cohort and 39.0% and 86.4%, respectively, for the 2nd validation cohort. In multivariate analysis of the first cohort, patients with refractory pouchitis or Crohn’s disease were 28 times (95% CI, 7.3–107.1) more likely to have pyloric gland metaplasia than those with a normal pouch or irritable pouch syndrome. The factor of refractory pouchitis or Crohn’s disease remained in the model for the 2nd validation cohort with odds ratio of 4.58 (95% CI, 1.6–13.4).

Conclusions  Pyloric gland metaplasia is associated with diagnosis of chronic antibiotic‐refractory pouchitis or Crohn’s disease of the pouch and appears to be a specific marker for both disease entities.
More food, less habitat: how necromass and leaf litter decomposition combine to regulate a litter ant community
Authors: SHIK JONATHAN Z. , KASPARI MICHAEL
Published: January 2010

1. In brown food webs of the forest floor, necromass (e.g. insect carcasses and frass) falling from the canopy feeds both microbes and ants, with the former decomposing the homes of the latter. In a tropical litter ant community, we added necromass to 1 m2 plots, testing if it added as a net food (increasing ant colony growth and recruitment) or destroyer of habitat (by decomposing leaf litter).

2. Maximum, but not mean, colony growth rates were higher on +food plots. However, neither average colony size, nor density was higher on +food plots. In contrast, +food plots saw diminished availability of leaf litter and higher microbial decomposition of cellulose, a main component of the organic substrate that comprises litter habitat.

3. Furthermore, necromass acted as a limiting resource to the ant community only when nest sites were supplemented on +food plots in a second experiment. Many of these +food +nest plots were colonised by the weedy species Wasmannia auropunctata.

4. Combined, these results support the more food–less habitat hypothesis and highlight the importance of embedding studies of litter ant ecology within broader decomposer food web dynamics.
Physical activity for prevention of osteoporosis in patients with severe haemophilia on long‐term prophylaxis
Authors: KHAWAJI M. , ASTERMARK J. , ÅKESSON K. , BERNTORP E.
Published: January 2010

Summary.  Physical activity has been considered as an important factor for bone density and as a factor facilitating prevention of osteoporosis. Bone density has been reported to be reduced in haemophilia. To examine the relation between different aspects of physical activity and bone mineral density (BMD) in patients with severe haemophilia on long‐term prophylaxis. The study group consisted of 38 patients with severe haemophilia (mean age 30.5 years). All patients received long‐term prophylaxis to prevent bleeding. The bone density (BMD g cm−2) of the total body, lumbar spine, total hip, femoral neck and trochanter was measured by dual energy X‐ray absorptiometry. Physical activity was assessed using the self‐report Modifiable Activity Questionnaire, an instrument which collects information about leisure and occupational activities for the prior 12 months. There was only significant correlation between duration and intensity of vigorous physical activity and bone density at lumber spine L1‐L4; for duration (r = 0.429 and P = 0.020) and for intensity (r = 0.430 and P = 0.019); whereas no significant correlation between all aspects of physical activity and bone density at any other measured sites. With adequate long‐term prophylaxis, adult patients with haemophilia are maintaining bone mass, whereas the level of physical activity in terms of intensity and duration play a minor role. These results may support the proposition that the responsiveness to mechanical strain is probably more important for bone mass development in children and during adolescence than in adults and underscores the importance of early onset prophylaxis.
Differential regulation of toll‐like receptor‐2, toll‐like receptor‐4, CD16 and human leucocyte antigen‐DR on peripheral blood monocytes during mild and severe dengue fever
Authors: Azeredo Elzinandes L. , Neves‐Souza Patrícia C. , Alvarenga Allan R. , Reis Sônia R. N. I. , Torrentes‐Carvalho Amanda , Zagne Sonia‐Maris O. , Nogueira Rita M. R. , Oliveira‐Pinto Luzia M. , Kubelka Claire F.
Published: January 2010

Dengue fever (DF), a public health problem in tropical countries, may present severe clinical manifestations as result of increased vascular permeability and coagulation disorders. Dengue virus (DENV), detected in peripheral monocytes during acute disease and in in vitro infection, leads to cytokine production, indicating that virus–target cell interactions are relevant to pathogenesis. Here we investigated the in vitro and in vivo activation of human peripheral monocytes after DENV infection. The numbers of CD14+ monocytes expressing the adhesion molecule intercellular adhesion molecule 1 (ICAM‐1) were significantly increased during acute DF. A reduced number of CD14+ human leucocyte antigen (HLA)‐DR+ monocytes was observed in patients with severe dengue when compared to those with mild dengue and controls; CD14+ monocytes expressing toll‐like receptor (TLR)2 and TLR4 were increased in peripheral blood from dengue patients with mild disease, but in vitro DENV‐2 infection up‐regulated only TLR2. Increased numbers of CD14+ CD16+ activated monocytes were found after in vitro and in vivo DENV‐2 infection. The CD14high CD16+ monocyte subset was significantly expanded in mild dengue, but not in severe dengue. Increased plasma levels of tumour necrosis factor‐α (TNF‐α), interferon‐γ (IFN‐γ) and interleukin (IL)‐18 in dengue patients were inversely associated with CD14high CD16+, indicating that these cells might be involved in controlling exacerbated inflammatory responses, probably by IL‐10 production. We showed here, for the first time, phenotypic changes on peripheral monocytes that were characteristic of cell activation. A sequential monocyte‐activation model is proposed in which DENV infection triggers TLR2/4 expression and inflammatory cytokine production, leading eventually to haemorrhagic manifestations, thrombocytopenia, coagulation disorders, plasmatic leakage and shock development, but may also produce factors that act in order to control both intense immunoactivation and virus replication.
Androgenic and Oestrogenic Influences on Tyrosine Hydroxylase‐Immunoreactive Cells of the Prairie Vole Medial Amygdala and Bed Nucleus of the Stria Terminalis
Authors: Cavanaugh B. L. , Lonstein J. S.
Published: January 2010

The posterodorsal medial amygdala (MeApd) and principal nucleus of the bed nucleus of the stria terminalis (pBST) are densely interconnected sites integrating steroid hormone and olfactory information necessary for sociosexual behaviours in many rodents. Our laboratory recently reported sexually dimorphic populations of cells containing tyrosine hydroxylase (TH) located in the MeApd and pBST of prairie voles (Microtus ochrogaster), with males having many more TH‐immunoreactive (‐ir) cells in these sites than do females. Gonadal hormones circulating during adulthood were showm to regulate this sex difference because it was eliminated by castrating adult males or implanting females with testosterone‐filled capsules. In the present study, we demonstrate that many (25–65%) TH‐ir cells in the MeApd and pBST of adult virgin male and female prairie voles also contain immunoreactivity for either the androgen receptor or oestrogen receptor α. Subcutaneous implants of oestradiol benzoate mimicked the effects of testosterone and maintained high numbers of TH‐ir cells in these sites in castrated males. However, implants of dihydrotestosterone (DHT) did not, and these males had low numbers of TH‐ir cells similar to castrated males given empty capsules. A similar effect was found in females, where testosterone or oestradiol benzoate greatly increased the number of TH‐ir cells in these sites compared to intact or ovariectomised controls, but DHT did not. DHT implants did, however, maintain high seminal vesicle weights in males. Thus, many of the TH‐ir cells in the prairie vole MeApd and pBST are potentially sensitive to androgens and oestrogens, although maintaining immunocytochemically detectable levels of TH in these cells may depend more on an oestrogen‐mediated mechanism in both sexes. These data have implications for understanding how gonadal hormone release across the reproductive cycle modulates these species‐specific groups of catecholaminergic cells and socially monogamous behaviours in prairie voles.
Oestrogen Receptors Enhance Dopamine Neurone Survival in Rat Midbrain
Authors: Johnson M. L. , Ho C. C. , Day A. E. , Walker Q. D. , Francis R. , Kuhn C. M.
Published: January 2010

Previous findings in our laboratory and elsewhere have shown that ovariectomy of rats in adulthood attenuates cocaine‐stimulated locomotor behaviour. Ovarian hormones enhance both cocaine‐stimulated behaviour and increase dopamine overflow after psychomotor stimulants. The present study aimed to determine whether ovarian hormones have these effects in part by maintaining dopamine neurone number in the substantia nigra pars compacta (SNpc) and ventral tegmental area (VTA) and to investigate the roles of specific oestrogen receptors (ERs) in the maintenance of mesencephalic dopamine neurones. To accomplish this goal, we used unbiased stereological techniques to estimate the number of tyrosine hydroxylase‐immunoreactive (TH‐IR) cell bodies in midbrain regions of intact, ovariectomised and hormone‐replaced female rats and mice. Animals received active or sham gonadectomy on postnatal day 60 and received vehicle, 17β‐oestradiol (E2) or selective ER agonists propyl‐pyrazole‐triol (PPT, ERα) or diarylpropionitrile (DPN, ERβ) for 1 month post‐surgery. In both rats and mice, ovariectomy reduced the number of TH‐IR cells in the SNpc and VTA. Replacement with E2, PPT or DPN prevented or attenuated the loss observed with ovariectomy in both rats and mice. An additional study using ER knockout mice revealed that adult female mice lacking ERα had fewer TH‐IR cells in midbrain regions than wild‐type mice, whereas mice lacking ERβ had TH‐IR cell counts comparable to wild‐type. These findings suggest that, although both ER subtypes play a role in the maintenance of TH‐IR cell number in the SNpc and VTA, ERα may play a more significant role.
Cutaneous melanoma in New Zealand: 2000–2004
Authors: Liang Jennifer J. C. , Robinson Elizabeth , Martin Richard C. W.
Published: January 2010

Background:  In 2004, we published data on the trends in New Zealand (NZ) cutaneous melanoma (CM) for the period 1995–1999. The present report documents the trends in the next period from 2000 to 2004.

Method:  Data were obtained from the New Zealand Cancer Registry by way of a computerized search of CM ICD‐10 (172) codes from 2000 to 2004. Only one registration per person was made to avoid including patients with metastatic melanoma. The exclusion criteria were: incorrect or absent data; benign naevi; and melanoma in situ. Incidence rates were age standardised to the Segi world population.

Results:  The total study population was 8262 patients. There was no increase found in the overall incidence rate over the time period, but men had a statistically higher overall incidence rate (P= 0.0002) and thicker CMs (P= 0.003) compared with women. This gender difference was particularly marked in those patients aged greater than 59 years. Breslow thickness increased from 0.7 to 0.8 mm. The incidence rates varied quite significantly among District Health Boards, with Taranaki having the highest rate (70.3/100 000/year) and Southland had the lowest rate (20.1/100 000). Overall, NZ had a CM incidence rate of 41.2/100 000/year).

Conclusion:  The current study confirmed that NZ has the highest overall CM incidence rate in the world. Elderly men (>59 years old) have the highest risk of developing melanoma. The increase in melanoma thickness with its associated higher mortality risk is of grave concern.
Dynamics of marine bacterial and phytoplankton populations using multiplex liquid bead array technology
Authors: Mayali Xavier , Palenik Brian , Burton Ronald S.
Published: January 2010

Heterotrophic bacteria and phytoplankton dominate the biomass and play major roles in the biogeochemical cycles of the surface ocean. Here, we designed and tested a fast, high‐throughput and multiplexed hybridization‐based assay to detect populations of marine heterotrophic bacteria and phytoplankton based on their small subunit ribosomal DNA sequences. The assay is based on established liquid bead array technology, an approach that is gaining acceptance in biomedical research but remains underutilized in ecology. End‐labelled PCR products are hybridized to taxon‐specific oligonucleotide probes attached to fluorescently coded beads followed by flow cytometric detection. We used ribosomal DNA environmental clone libraries (a total of 450 clones) and cultured isolates to design and test 26 bacterial and 10 eukaryotic probes specific to various ribotypes and genera of heterotrophic bacteria and eukaryotic phytoplankton. Pure environmental clones or cultures were used as controls and demonstrated specificity of the probes to their target taxa. The quantitative nature of the assay was demonstrated by a significant relationship between the number of target molecules and fluorescence signal. Clone library sequencing and bead array fluorescence from the same sample provided consistent results. We then applied the assay to a 37‐day time series of coastal surface seawater samples from the Southern California Bight to examine the temporal dynamics of microbial communities on the scale of days to weeks. As expected, several bacterial phylotypes were positively correlated with total bacterial abundances and chlorophyllaconcentrations, but others were negatively correlated. Bacterial taxa belonging to the same broad taxonomic groups did not necessarily correlate with one another, confirming recent results suggesting that inferring ecological role from broad taxonomic identity may not always be accurate.
Stimulating the anaerobic degradation of aromatic hydrocarbons in contaminated sediments by providing an electrode as the electron acceptor
Authors: Zhang Tian , Gannon Sarah M. , Nevin Kelly P. , Franks Ashley E. , Lovley Derek R.
Published: January 2010

The possibility that electrodes might serve as an electron acceptor to simulate the degradation of aromatic hydrocarbons in anaerobic contaminated sediments was investigated. Initial studies with Geobacter metallireducens demonstrated that although toluene was rapidly adsorbed onto the graphite electrodes it was rapidly oxidized to carbon dioxide with the electrode serving as the sole electron acceptor. Providing graphite electrodes as an electron acceptor in hydrocarbon‐contaminated sediments significantly stimulated the removal of added toluene and benzene. Rates of toluene and benzene removal accelerated with continued additions of toluene and benzene. [14C]‐Toluene and [14C]‐benzene were quantitatively recovered as [14C]‐CO2, demonstrating that even though the graphite adsorbed toluene and benzene they were degraded. Introducing an electrode as an electron acceptor also accelerated the loss of added naphthalene and [14C]‐naphthalene was converted to [14C]‐CO2. The results suggest that graphite electrodes can serve as an electron acceptor for the degradation of aromatic hydrocarbon contaminants in sediments, co‐localizing the contaminants, the degradative organisms and the electron acceptor. Once in position, they provide a permanent, low‐maintenance source of electron acceptor. Thus, graphite electrodes may offer an attractive alternative for enhancing contaminant degradation in anoxic environments.