bluuebunny/crossref_metadata_2025 huggingface dataset:
ISG15 inhibits Ebola VP40 VLP budding in an L-domain-dependent manner by blocking Nedd4 ligase activity
Authors: Okumura Atsushi , Pitha Paula M. , Harty Ronald N.
Published: February 2008

Ebola virus budding is mediated by the VP40 matrix protein. VP40 can bud from mammalian cells independent of other viral proteins, and efficient release of VP40 virus-like particles (VLPs) requires interactions with host proteins such as tsg101 and Nedd4, an E3 ubiquitin ligase. Ubiquitin itself is thought to be exploited by Ebola virus to facilitate efficient virus egress. Disruption of VP40 function and thus virus budding remains an attractive target for the development of novel antiviral therapies. Here, we investigate the effect of ISG15 protein on the release of Ebola VP40 VLPs. ISG15 is an IFN-inducible, ubiquitin-like protein expressed after bacterial or viral infection. Our results show that expression of free ISG15, or the ISGylation system (UbE1L and UbcH8), inhibits budding of Ebola virus VP40 VLPs. Addressing the molecular mechanism of this inhibition, we show that ISG15 interacts with Nedd4 ubiquitin ligase and inhibits ubiquitination of VP40. Furthermore, the L-domain deletion mutant of VP40 (ΔPT/PY), which does not interact with Nedd4, was insensitive to ISG15-mediated inhibition of VLP release. These data provide evidence of antiviral activity of ISG15 against Ebola virus and suggest a mechanism of action involving disruption of Nedd4 function and subsequent ubiquitination of VP40.
Mediterranean‐type diet and risk of preterm birth among women in the Norwegian Mother and Child Cohort Study (MoBa): a prospective cohort study
Authors: HAUGEN MARGARETHA , MARGRETE MELTZER HELLE , LISE BRANTSÆTER ANNE , MIKKELSEN TINA , LOUISE ØSTERDAL MARIE , ALEXANDER JAN , OLSEN SJURDUR F. , BAKKETEIG LEIV
Published: February 2008

Background. Mediterranean diet has been shown to reduce the incidence of preterm birth. We wanted to investigate whether a Mediterranean‐type diet (MD) could be associated with a lower risk of preterm birth in the Norwegian Mother and Child Cohort Study (MoBa). Methods. The data collection was conducted as part of MoBa at the Norwegian Institute of Public Health. In MoBa, women answer a Food Frequency Questionnaire (FFQ) at week 18–22 of pregnancy. The MD criteria were intake of fish ≥2 times a week, fruit and vegetables ≥5 times a day, use of olive/canola oil, red meat intake ≤ times 2 a week, and ≤2 cups of coffee a day. Results. A total of 569 women (2.2%) met the MD criteria, 25,397 women (97.2%) met 1–4 criteria, and 159 women (0.01%) met none of the MD criteria. The number of preterm births in the MD group was 26 (4.6%), in those who met 1–4 criteria it was 1,148 (4.5%), and in those who met none of the criteria it was 10 (6.3%). The women who met the MD criteria did not have reduced risk of preterm birth compared with women meeting none of the MD criteria (OR: 0.73; 95% CI: 0.32, 1.68). Intake of fish twice or more a week was associated with a lower risk of preterm birth (OR: 0.84; 95% CI: 0.74, 0.95). Conclusions. The women who fulfilled the criteria of a MD did not have a reduced risk of preterm birth.
Comment on causality and pathway search in microarray time series experiment
Authors: Nagarajan Radhakrishnan , Upreti Meenakshi
Published: February 2008

Contact:  nagarajanradhakrish@uams.edu
Oxidative Pentose Phosphate Pathway-Dependent Sugar Sensing as a Mechanism for Regulation of Root Ion Transporters by Photosynthesis
Authors: Lejay Laurence , Wirth Judith , Pervent Marjorie , Cross Joanna Marie-France , Tillard Pascal , Gojon Alain
Published: February 2008

Root ion transport systems are regulated by light and/or sugars, but the signaling mechanisms are unknown. We showed previously that induction of the NRT2.1 NO3  − transporter gene by sugars was dependent on carbon metabolism downstream hexokinase (HXK) in glycolysis. To gain further insights on this signaling pathway and to explore more systematically the mechanisms coordinating root nutrient uptake with photosynthesis, we studied the regulation of 19 light-/sugar-induced ion transporter genes. A combination of sugar, sugar analogs, light, and CO2 treatments provided evidence that these genes are not regulated by a common mechanism and unraveled at least four different signaling pathways involved: regulation by light per se, by HXK-dependent sugar sensing, and by sugar sensing upstream or downstream HXK, respectively. More specific investigation of sugar-sensing downstream HXK, using NRT2.1 and NRT1.1 NO3  − transporter genes as models, highlighted a correlation between expression of these genes and the concentration of glucose-6-P in the roots. Furthermore, the phosphogluconate dehydrogenase inhibitor 6-aminonicotinamide almost completely prevented induction of NRT2.1 and NRT1.1 by sucrose, indicating that glucose-6-P metabolization within the oxidative pentose phosphate pathway is required for generating the sugar signal. Out of the 19 genes investigated, most of those belonging to the NO3  −, NH4  +, and SO4  2− transporter families were regulated like NRT2.1 and NRT1.1. These data suggest that a yet-unidentified oxidative pentose phosphate pathway-dependent sugar-sensing pathway governs the regulation of root nitrogen and sulfur acquisition by the carbon status of the plant to coordinate the availability of these three elements for amino acid synthesis.
Global Transcript Levels Respond to Small Changes of the Carbon Status during Progressive Exhaustion of Carbohydrates in Arabidopsis Rosettes
Authors: Usadel Björn , Bläsing Oliver E. , Gibon Yves , Retzlaff Kristin , Höhne Melanie , Günther Manuela , Stitt Mark
Published: February 2008

The balance between the supply and utilization of carbon (C) changes continually. It has been proposed that plants respond in an acclimatory manner, modifying C utilization to minimize harmful periods of C depletion. This hypothesis predicts that signaling events are initiated by small changes in C status. We analyzed the global transcriptional response to a gradual depletion of C during the night and an extension of the night, where C becomes severely limiting from 4 h onward. The response was interpreted using published datasets for sugar, light, and circadian responses. Hundreds of C-responsive genes respond during the night and others very early in the extended night. Pathway analysis reveals that biosynthesis and cellular growth genes are repressed during the night and genes involved in catabolism are induced during the first hours of the extended night. The C response is amplified by an antagonistic interaction with the clock. Light signaling is attenuated during the 24-h light/dark cycle. A model was developed that uses the response of 22K genes during a circadian cycle and their responses to C and light to predict global transcriptional responses during diurnal cycles of wild-type and starchless pgm mutant plants and an extended night in wild-type plants. By identifying sets of genes that respond at different speeds and times during C depletion, our extended dataset and model aid the analysis of candidates for C signaling. This is illustrated for AKIN10 and four bZIP transcription factors, and sets of genes involved in trehalose signaling, protein turnover, and starch breakdown.
An efficient on‐column expressed protein ligation strategy: Application to segmental triple labeling of human apolipoprotein E3
Authors: Zhao Wentao , Zhang Yonghong , Cui Chunxian , Li Qianqian , Wang Jianjun
Published: February 2008

Expressed protein ligation (EPL) is an intein‐based approach that has been used for protein engineering and biophysical studies of protein structures. One major problem of the EPL is the low yield of final ligation product, primarily due to the complex procedure of the EPL, preventing EPL from gaining popularity in the research community. Here we report an efficient on‐column EPL strategy, which focuses on enhancing the expression level of the intein‐fusion protein that generates thioester for the EPL. We applied this EPL strategy to human apolipoprotein E (apoE) and routinely obtained 25–30 mg segmental, triple‐labeled apoE from 1‐L cell culture. The approaches reported here are general approaches that are not specific for apoE, thus providing a general strategy for a highly efficient EPL. In addition, we also report an isotopic labeling scheme that double‐labels one domain and keeps the other domain of apoE deuterated. Such an isotopic labeling scheme can only be achieved using the EPL strategy. Our data indicated that the segmental triple‐labeled apoEs using this labeling scheme produced high‐quality, simplified NMR spectra, facilitating NMR spectral assignment. For large proteins, such as apoE, perdeuterated protein samples have to be used to reduce the linewidth of NMR signals, causing a major problem for the NOE‐based NMR method, since perdeuterated proteins lack protons for NOE measurement. The new labeling strategy solves this problem and provides 13C/15N double‐labeled, protonated protein domains, allowing for determination of high‐resolution NMR structure of these large proteins.
Local Structure and Properties of Oxide Surfaces: Scanning Probe Analyses of Ceramics
Authors: Bonnell Dawn A.
Published: February 2008

Scanning probe microscopies, especially scanning tunneling microscopy, were first directed to metal and semiconductor surfaces. Early challenges associated with the low conductivity and ionicity of oxides slowed application to even semiconducting ceramics. Recently, some of these obstacles have been overcome, and probe microscopies have been used to determine the atomic structures, as well as local properties, of many oxide surfaces and interfaces. Approaches to quantifying both tunneling spectroscopy and tunneling images of oxides are presented. Oxide surfaces accommodate nonstoichiometry via reconstruction or surface stabilization of substoichiometric phases. Effects of self‐segregation and of impurity segregation on local properties of surfaces are observed directly. Three examples of local properties at interfaces are presented: contact potential at nanoscale metal cluster‐oxide interfaces, local electrostatic fields at grain boundaries, and current flow in complex superconducting microstructures.
Mechanical Properties of Solid‐State‐Synthesized Strontium‐ and Magnesium‐Doped Lanthanum Gallate
Authors: Sammes Nigel M. , Keppeler F. Michael , Näfe Helfried , Aldinger Fritz
Published: February 2008

This paper has examined the room‐temperature mechanical properties of La0.8Sr0.2Ga1−xMgxO3−δ (x = 0.1–0.2) that was synthesized by using a solid‐state technique. The modulus of rupture (MOR) was measured over the range of x = 0.1–0.2 and decreased as the B‐site dopant content increased. At x = 0.15, for example, the MOR was 139 ± 17 MPa, whereas at x = 0.2, an MOR value of 113 ± 8 MPa was observed. This decrease is postulated as being caused by the increased lattice stress due to the increased magnesium concentration on the B‐site. The fracture toughness of the sample decreased as the magnesium content increased; at x = 0.15, a fracture toughness of 1.63 ± 0.2 MPam1/2 was observed, whereas at x = 0.2, a value of 1.28 MPam1/2 was obtained.
Alumina/Epoxy Interpenetrating Phase Composite Coatings: I, Processing and Microstructural Development
Authors: Craig Bradley D. , Francis Lorraine F.
Published: February 2008

Interpenetrating phase composite (IPC) coatings consisting of continuously connected Al2O3 and epoxy phases were fabricated. The ceramic phase was prepared by depositing an aqueous dispersion of Al2O3 (0.3 μm) containing orthophosphoric acid, H3PO4, (1–9.6 wt%, solid basis) and heating to create phosphate bonds between particles. The resulting ceramic coating was porous, which allowed the infiltration and curing of a second‐phase epoxy resin. The effect of dispersion composition and thermal processing conditions on the phosphate bonding and ceramic microstructure was investigated. Reaction between Al2O3 and H3PO4 generated an aluminum phosphate layer on particle surfaces and between particles; this bonding phase was initially amorphous, but partially crystallized upon heating to 500°C. Flexural modulus measurements verified the formation of bonds between particles. The coating porosity (and hence epoxy content in the final IPC coating) decreased from ∼50% to 30% with increased H3PO4 loading. The addition of aluminum chloride, AlCl3, enhanced bonding at low temperatures but did not change the porosity. Diffuse reflectance FTIR showed that a combination of UV and thermal curing steps was necessary for complete curing of the infiltrated epoxy phase. Al2O3/epoxy IPC coatings prepared by this method can range in thickness from 1 to 100 μm and have potential applications in wear resistance.
Effect of Initial α‐Phase Content on Microstructure and Mechanical Properties of Sintered Silicon Carbide
Authors: Kim Young‐Wook , Mitomo Mamoru , Emoto Hideyuki , Lee June‐Gunn
Published: February 2008

By using α‐ and β‐SiC starting powders with similar particle sizes, the effects of initial α‐phase content on the microstructure and the mechanical properties of the liquid‐phase‐sintered and subsequently annealed materials were investigated. The microstructures developed were analyzed by image analysis. When β‐SiC powder was used, the grains became elongated. The average diameter decreased with increasing α‐SiC content and the aspect ratio showed a maximum at 10%α‐SiC and decreased with increasing α‐SiC content in the starting powder. Such results suggest that microstructure can be controlled by changing α‐phase content in starting powders. The strength increased with increasing α‐SiC content in the starting powder while the fracture toughness decreased with increasing α‐SiC content. There may be a trade‐off in improving both the strength and toughness in SiC ceramics sintered with oxide additives.
Ferroelectric Thin Films of Bismuth‐Containing Layered Perovskites: Part I, Bi4Ti3O12
Authors: Du Xiaofeng , Chen I‐Wei
Published: February 2008

Ferroelectric thin films of bismuth‐containing layered perovskite Bi4Ti3O12 have been fabricated by a metalorganic decomposition (MOD) method. Crack‐free and crystalline films of ∼5000 Å thickness have been deposited on Pt/Ti/SiO2/Si substrates. Different heat treatments have been studied to investigate the nucleation and growth of perovskite Bi4Ti3O12 crystallites. If the same composition and final annealing temperature are used, films with different orientations are obtained by different heating schedules. These films show a large anisotropy in ferroelectric properties. Theoretical considerations are presented to suggest that nucleation control is responsible for texture and grain‐size evolution. Moreover, the origin of the ferroelectric anisotropy is rooted in the two‐dimensional nature of layered polarization.
Grain‐Boundary Viscosity of Polycrystalline Silicon Carbides
Authors: Pezzotti Giuseppe , Kleebe Hans‐Joachim , Ota Ken'ichi
Published: February 2008

Internal friction experiments were conducted on three SiC polycrystalline materials with different microstructural characteristics. Characterizations of grain‐boundary structures were performed by high‐resolution electron microscopy (HREM). Observations revealed a common glass‐film structure at grain boundaries of two SiC materials, which contained different amounts of SiO2 glass. Additional segregation of residual graphite and SiO2 glass was found at triple pockets, whose size was strongly dependent on the amount of SiO2 in the material. The grain boundaries of a third material, processed with B and C addition, were typically directly bonded without any residual glass phase. Internal friction data of the three SiC materials were collected up to similar/congruent2200°C. The damping curves as a function of temperature of the SiO2‐bonded materials revealed the presence of a relaxation peak, arising from grain‐boundary sliding, superimposed on an exponential‐like background. In the directly bonded SiC material, only the exponential background could be detected. The absence of a relaxation peak was related to the glass‐free grain‐boundary structure of this polycrystal, which inhibited sliding. Frequency‐shift analysis of the internal friction peak in the SiO2‐containing materials enabled the determination of the intergranular film viscosity as a function of temperature.
Luminescence Characterization of Chromium‐Containing theta‐Alumina
Authors: Wen Qingzhe , Lipkin Donald M. , Clarke David R.
Published: February 2008

Characteristic photostimulated luminescence (fluorescence) in the visible range is reported from theta transition alumina prepared by using a variety of methods. The luminescence is associated with trace concentrations of chromium and can be intensified by intentional chromium doping. The luminescence from theta‐alumina is similar to, albeit considerably weaker than, the R‐line luminescence from alpha‐alumina. The theta‐alumina spectrum is characterized by a doublet at ∼14575 and 14645 cm−1 at 77 K and is blue‐shifted from the R‐lines of alpha‐alumina by ∼150 cm−1. The doublet is attributed to Cr3+ ions in octahedral coordination and can be used for phase identification in microstructural characterization.
Factor XI deficiency
Authors: GOMEZ K. , BOLTON‐MAGGS P.
Published: February 2008

Summary.  Although factor XI (FXI) deficiency has a particularly high incidence in Ashkenazi Jews, it is now frequently diagnosed in other ethnic groups. This review gives an overview of the basic pathophysiology, clinical manifestations, and management of FXI deficiency. The correlation between FXI levels and the bleeding phenotype is much less clear than in the haemophilias, and consequently the bleeding risk can be difficult to predict. Two well‐characterized mutations in the F11 gene are responsible for the majority of Jewish cases, but new mutations are becoming increasingly recognized. The publication of the crystal structure has greatly enhanced our understanding of the structure–function relationship in FXI. The impact of recent studies on our understanding of the role of FXI in coagulation is discussed.
Ex vivo evaluation of the accuracy of two electronic apex locators during root canal length determination in primary teeth
Authors: Leonardo M. R. , Silva L. A. B. , Nelson‐Filho P. , Silva R. A. B. , Raffaini M. S. G. G.
Published: February 2008

Aim  To evaluate ex vivo the accuracy of two electronic apex locators during root canal length determination in primary incisor and molar teeth with different stages of physiological root resorption.

Methodology  One calibrated examiner determined the root canal length in 17 primary incisors and 16 primary molars (total of 57 root canals) with different stages of root resorption based on the actual canal length and using two electronic apex locators. Root canal length was measured both visually, with the placement of a K‐file 1 mm short of the apical foramen or the apical resorption bevel, and electronically using two electronic apex locators (Root ZX II – J. Morita Corp. and Mini Apex Locator – SybronEndo) according to the manufacturers’ instructions. Data were analysed statistically using the intraclass correlation (ICC) test.

Results  Comparison of the actual root canal length and the electronic root canal length measurements revealed high correlation (ICC = 0.99), regardless of the tooth type (single‐rooted and multi‐rooted teeth) or the presence/absence of physiological root resorption.

Conclusions  Root ZX II and Mini Apex Locator proved useful and accurate for apex foramen location during root canal length measurement in primary incisors and molars.
Dimensional characterization and mechanical behaviour of K3 rotary instruments
Authors: Melo M. C. C. , Pereira E. S. J. , Viana A. C. D. , Fonseca A. M. A. , Buono V. T. L. , Bahia M. G. A.
Published: February 2008

Aim  To correlate the mechanical behaviour in torsion, bending and fatigue tests of K3 instruments with their dimensional characteristics.

Methodology  Instrument length, tip angle, distance between blades (pitch length) and the diameter at each millimetre from the tip of sizes 20, 25 and 30, 0.04 taper and sizes 20 and 25, 0.06 taper K3 rotary instruments were measured in an optical microscope equipped with digital micrometers. The cross‐sectional area at 3 mm from the tip of the same instruments was determined using digital image analysis of scanning electron microscopy images. Maximum torque and angular deflection, as well as bending moment at 45° were measured according to specification of ISO 3630‐1. Fatigue resistance of instruments size 30, 0.04 taper, and sizes 20 and 25, 0.06 taper was determined in a fatigue test bench device.

Results  The analysed instruments presented no uniformity in the distance between adjacent blades, but the measured diameters at each millimetre from the tip were regular, showing compliance with manufacturing standards. Torque and bending moment of the tested instruments increased significantly with diameter and cross‐sectional area at 3 mm from the instrument tip. The fatigue resistance of the instruments showed a tendency to decrease as the diameter of the instruments increased.

Conclusions  The bending moment at 45° and the torsional resistance of K3 instruments can be predicted using instrument diameter and cross‐sectional area at 3 mm from the tip. Fatigue resistance decreased as the instrument diameter increased.
Are high‐coherent concept maps better for prior knowledge activation? Differential effects of concept mapping tasks on high school vs. university students
Authors: Gurlitt J. , Renkl A.
Published: February 2008

Abstract  We investigated whether and how prior knowledge activation improves learning outcomes for high school (less experienced learners) and university students (experienced learners) in a hypertext environment. Map coherence was defined as the extent to which relationships between the concepts in the map were made explicit. Therefore, we classified the mapping task of creating and labelling lines as low‐coherent, and the mapping task of labelling provided lines as high‐coherent. Learners were randomly assigned to the conditions of (1) high‐coherent knowledge activation; (2) low‐coherent knowledge activation; and (3) a baseline condition without prior knowledge activation. We found an overall effect for prior knowledge activation, learning experience, and an interaction between learning experience and the coherence of the prior knowledge activation task on learning outcomes. High school students benefited most from labelling provided lines, while university physics majors benefited most from creating and labelling lines. This interaction effect and effects of the specific mapping tasks on process measures support the claim that different prior knowledge activation tasks are suited for different groups of learners.
Structure and process factors that influence patients' perception of inpatient psychiatric nursing care at Mathari hospital, Nairobi
Authors: WAGORO M. C. A. , OTHIENO C. J. , MUSANDU J. , KARANI A.
Published: February 2008

To explore structure and process factors which influence patients' perception of quality inpatient psychiatric nursing care at Mathari hospital. This was a cross‐sectional study of 236 inpatients selected by stratified random sampling. Competence to give consent was determined by a minimum score of 24 on Mini Mental State Examination. Patients were interviewed using a semi‐structured questionnaire. Differences in proportions of variables were determined by calculating confidence interval and summary chi‐squared statistics. P‐values of ≤0.05 were considered significant. Majority of patients (87%) were aged 20–49 years with 43% having stayed in the ward for over a month. Structure factors related to patients' perception of care included physical environment, being happy with the way the ward looked was significantly related to satisfaction with care (χ2 = 5.506, P = 0002). Process factors significantly related to patients' satisfaction with care included nurses providing patients with information on prescribed medicines (χ2 = 10.50, P = 00012). Satisfaction with care was positively related to ability to recommend someone for admission in the same ward (χ2 = 20.2, P = 00001). Structure and process factors identified as influencing patients' perception of care were physical environment and nurses' qualities that fit within the characteristics of Peplau's Interpersonal Relations Theory.
Disagreement between subjective and actigraphic measures of sleep duration in a population‐based study of elderly persons*
Authors: VAN DEN BERG JULIA F. , VAN ROOIJ FRANK J.A. , VOS HENK , TULEN JOKE H.M. , HOFMAN ALBERT , MIEDEMA HENK M.E. , NEVEN ARIE KNUISTINGH , TIEMEIER HENNING
Published: February 2008

Sleep duration is an important concept in epidemiological studies. It characterizes a night’s sleep or a person’s sleep pattern, and is associated with numerous health outcomes. In most large studies, sleep duration is assessed with questionnaires or sleep diaries. As an alternative, actigraphy may be used, as it objectively measures sleep parameters and is feasible in large studies. However, actigraphy and sleep diaries may not measure exactly the same phenomenon. Our study aims to determine disagreement between actigraphic and diary estimates of sleep duration, and to investigate possible determinants of this disagreement. This investigation was embedded in the population‐based Rotterdam Study. The study population consisted of 969 community‐dwelling participants aged 57–97 years. Participants wore an actigraph and kept a sleep diary for, on average, six consecutive nights. Both measures were used to determine total sleep time (TST). In 34% of the participants, the estimated TST in the sleep diaries deviated more than 1 h from actigraphically measured TST. The level of disagreement between diary and actigraphic measures decreased with subjective and actigraphic measures of sleep quality, and increased with male gender, poor cognitive function and functional disability. Actigraphically measured poor sleep was often accompanied by longer subjective estimates of TST, whereas subjectively poor sleepers tended to report shorter TST in their diaries than was measured with actigraphy. We recommend, whenever possible, to use multiple measures of sleep duration, to perform analyses with both, and to examine the consistency of the results over assessment methods.
The CBS subdomain of inosine 5′‐monophosphate dehydrogenase regulates purine nucleotide turnover
Authors: Pimkin Maxim , Markham George D.
Published: February 2008

Inosine 5′‐monophosphate dehydrogenase (IMPDH) catalyses the rate‐limiting step in guanine nucleotide biosynthesis. IMPDH has an evolutionary conserved CBS subdomain of unknown function. The subdomain can be deleted without impairing the in vitro IMPDH catalytic activity and is the site for mutations associated with human retinitis pigmentosa. A guanine‐prototrophic Escherichia coli strain, MP101, was constructed with the subdomain sequence deleted from the chromosomal gene for IMPDH. The ATP content was substantially elevated in MP101 whereas the GTP content was slighty reduced. The activities of IMPDH, adenylosuccinate synthetase and GMP reductase were two to threefold lower in MP101 crude extracts compared with the BW25113 wild‐type strain. Guanine induced a threefold reduction in the MP101 ATP pool and a fourfold increase in the GTP pool within 10 min of addition to growing cells; this response does not result from the reduced IMPDH activity or starvation for guanylates. In vivo kinetic analysis using 14‐C tracers and 33‐P pulse‐chasing revealed mutation‐associated changes in purine nucleotide fluxes and turnover rates. We conclude that the CBS subdomain of IMPDH may coordinate the activities of the enzymes of purine nucleotide metabolism and is essential for maintaining the normal ATP and GTP pool sizes in E. coli.
Effect of tolterodine on gastrointestinal transit and bowel habits in healthy subjects
Authors: Bharucha A. E. , Seide B. , Guan Z. , Andrews C. N. , Zinsmeister A. R.
Published: February 2008

Abstract  Clinical trials and observations suggest that constipation is an uncommon side effect of treating overactive bladder with the muscarinic receptor antagonist tolterodine. Because muscarinic antagonism inhibits gastrointestinal motor activity, we evaluated the effects of tolterodine on bowel habits, gastrointestinal and colonic transit in healthy subjects. In this double‐blind study, 36 healthy subjects were randomized to tolterodine extended release (ER, 4 mg daily) or placebo for 6 days. Gastric emptying (GE), small bowel and colonic transit were assessed on days 4–6 by scintigraphy. Bowel habits were recorded by diaries. Tolterodine did not significantly affect half‐time for GE (GE thalf) [116 ± 6 min (mean ± SEM) for placebo vs 126 ± 7 min for tolterodine], small bowel transit measured by colonic filling at 6 h (45 ± 6% for placebo vs 36 ± 6% for tolterodine) or the geometric center of colonic transit at 24 h (2.9 ± 0.2 for placebo vs 2.6 ± 0.3 for tolterodine). Subjects who received tolterodine had slightly fewer bowel movements (i.e. 1.34 ± 0.1 stools per day for placebo vs 1.0 ± 0.1 for tolterodine; P = 0.02 for treatment effect). Tolterodine did not significantly affect stool consistency or ease of defecation. At the therapeutic dose used to treat overactive bladder, tolterodine did not significantly affect gastrointestinal or colonic transit and had minor effects on bowel habits in healthy subjects. Further studies are necessary to elucidate whether these observations are explained by tolterodine effects at muscarinic receptors which stimulate and inhibit gastrointestinal motility.
Solutes, but not cells, drain from the brain parenchyma along basement membranes of capillaries and arteries: significance for cerebral amyloid angiopathy and neuroimmunology
Authors: Carare R. O. , Bernardes‐Silva M. , Newman T. A. , Page A. M. , Nicoll J. A. R. , Perry V. H. , Weller R. O.
Published: February 2008

Elimination of interstitial fluid and solutes plays a role in homeostasis in the brain, but the pathways are unclear. Previous work suggests that interstitial fluid drains along the walls of arteries. Aims: to define the pathways within the walls of capillaries and arteries for drainage of fluid and solutes out of the brain. Methods: Fluorescent soluble tracers, dextran (3 kDa) and ovalbumin (40 kDa), and particulate fluospheres (0.02 μm and 1.0 μm in diameter) were injected into the corpus striatum of mice. Brains were examined from 5 min to 7 days by immunocytochemistry and confocal microscopy. Results: soluble tracers initially spread diffusely through brain parenchyma and then drain out of the brain along basement membranes of capillaries and arteries. Some tracer is taken up by vascular smooth muscle cells and by perivascular macrophages. No perivascular drainage was observed when dextran was injected into mouse brains following cardiac arrest. Fluospheres expand perivascular spaces between vessel walls and surrounding brain, are ingested by perivascular macrophages but do not appear to leave the brain even following an inflammatory challenge with lipopolysaccharide or kainate. Conclusions: capillary and artery basement membranes act as ‘lymphatics of the brain’ for drainage of fluid and solutes; such drainage appears to require continued cardiac output as it ceases following cardiac arrest. This drainage pathway does not permit migration of cells from brain parenchyma to the periphery. Amyloid‐β is deposited in basement membrane drainage pathways in cerebral amyloid angiopathy, and may impede elimination of amyloid‐β and interstitial fluid from the brain in Alzheimer's disease. Soluble antigens, but not cells, drain from the brain by perivascular pathways. This atypical pattern of drainage may contribute to partial immune privilege of the brain and play a role in neuroimmunological diseases such as multiple sclerosis.
Effects of environmental parameters, leaf physiological properties and leaf water relations on leaf water δ18O enrichment in different Eucalyptus species
Authors: KAHMEN ANSGAR , SIMONIN KEVIN , TU KEVIN P. , MERCHANT ANDREW , CALLISTER ANDREW , SIEGWOLF ROLF , DAWSON TODD E. , ARNDT STEFAN K.
Published: February 2008

Stable oxygen isotope ratios (δ18O) have become a valuable tool in the plant and ecosystem sciences. The interpretation of δ18O values in plant material is, however, still complicated owing to the complex interactions among factors that influence leaf water enrichment. This study investigated the interplay among environmental parameters, leaf physiological properties and leaf water relations as drivers of the isotopic enrichment of leaf water across 17 Eucalyptus species growing in a common garden. We observed large differences in maximum daily leaf water δ18O across the 17 species. By fitting different leaf water models to these empirical data, we determined that differences in leaf water δ18O across species are largely explained by variation in the Péclet effect across species. Our analyses also revealed that species‐specific differences in transpiration do not explain the observed differences in δ18O while the unconstrained fitting parameter ‘effective path length’ (L) was highly correlated with δ18O. None of the leaf morphological or leaf water related parameters we quantified in this study correlated with the L values we determined even though L was typically interpreted as a leaf morphological/anatomical property. A sensitivity analysis supported the importance of L for explaining the variability in leaf water δ18O across different species. Our investigation highlighted the importance of future studies to quantify the leaf properties that influence L. Obtaining such information will significantly improve our understanding of what ultimately determines the δ18O values of leaf water across different plant species.
Metabolic interactions between algal symbionts and invertebrate hosts
Authors: YELLOWLEES DAVID , REES T. ALWYN V. , LEGGAT WILLIAM
Published: February 2008

Some invertebrates have enlisted autotrophic unicellular algae to provide a competitive metabolic advantage in nutritionally demanding habitats. These symbioses exist primarily but not exclusively in shallow tropical oceanic waters where clear water and low nutrient levels provide maximal advantage to the association. Mostly, the endosymbiotic algae are localized in host cells surrounded by a host‐derived membrane (symbiosome). This anatomy has required adaptation of the host biochemistry to allow transport of the normally excreted inorganic nutrients (CO2, NH3 and PO43−) to the alga. In return, the symbiont supplies photosynthetic products to the host to meet its energy demands. Most attention has focused on the metabolism of CO2 and nitrogen sources. Carbon‐concentrating mechanisms are a feature of all algae, but the products exported to the host following photosynthetic CO2 fixation vary. Identification of the stimulus for release of algal photosynthate in hospite remains elusive. Nitrogen assimilation within the symbiosis is an essential element in the host's control over the alga. Recent studies have concentrated on cnidarians because of the impact of global climate change resulting in coral bleaching. The loss of the algal symbiont and its metabolic contribution to the host has the potential to result in the transition from a coral‐dominated to an algal‐dominated ecosystem.
Understanding the pathway between the transplant experience and health‐related quality of life outcomes in adolescents
Authors: Simons Laura E. , Anglin Grace , Warshaw Barry L. , Mahle William T. , Vincent Robert N. , Blount Ronald L.
Published: February 2008

Abstract:  Developments in solid organ transplantation have resulted in improved survival for children with advanced kidney, liver, and heart disease; however, concerns have been raised regarding the quality of life of survivors. This study examined HRQOL in adolescent transplant recipients. We examined the influence of demographic, treatment regimen, and family factors on physical and mental health domains of HRQOL. The current single‐center investigation involved 68 solid organ transplant recipients and their parents. All families participated in a structured interview to collect information on demographics, characteristics of the adolescents’ disease and treatment regimen, family functioning, and HRQOL for parents and adolescents. Using hierarchical regression analyses, predictive models of physical functioning and mental health outcomes for adolescent transplant recipients were developed for parent‐proxy and adolescent self‐report. Perceived frequency of medication side‐effects and family conflict significantly contributed to adolescent physical functioning and mental health outcomes. Taken together, transplant consequences and family environment significantly impact physical and mental health outcomes in adolescent transplant recipients. Our findings demonstrate the need for pharmacological considerations and psychological interventions to address these areas.
Transfusion‐related acute lung injury in a child with neuroblastoma during a late engraftment period of autologous stem cell transplantation
Authors: Citak Elvan Caglar , Kesik Vural , Atay A. A. , Sari Erkan , Kismet Erol , Koseoglu Vedat
Published: February 2008

Abstract:  TRALI is a rare and serious complication of blood product transfusion characterized by acute respiratory distress, non‐cardiogenic pulmonary edema, hypoxia, fever, and hypotension developing during or up to six h following transfusion. The disease can be life‐threatening and should be considered whenever complications occur after a transfusion in stem cell transplant recipients. Caution should be exercised as the symptoms of TRALI are similar to diseases such as pulmonary hemorrhage, pulmonary edema, and engraftment syndrome. The neutrophil engraftment generally occurs after 14 days following allogeneic stem cell transplants. The diagnosis of TRALI becomes very difficult with late engraftments. Herein, we report TRALI in a pediatric recipient whose neutrophil engraftment occurred on day 67.
Inheritance of time of flowering in upland cotton under natural conditions
Authors: Hao J. J. , Yu S. X. , Ma Q. X. , Fan S. L. , Song M. Z.
Published: February 2008

Time to flowering is an essential component of the adaptation and productivity of cotton (Gossipium hirsutum) in various agro‐ecological zones. This article presents a study of the genetic control of this trait in two crosses obtained from different early‐maturity parental lines. In each cross, multiple generations including P1, F1, P2, B1, B2 and F2 were evaluated under two natural field conditions in 2004 and 2005. The data on time to flowering in the F2 populations had a continuous distribution but deviated from normality. A joint segregation analysis (JSA) revealed that time of flowering in upland cotton was controlled by a mixture of an additive major gene and additive‐dominant polygenes. The first‐ and second‐order genetic parameters were all calculated based on the mixture of major gene and polygene inheritance models using JSA. These results suggested that there was considerable genetic diversity and complexity in days to anthesis in upland cotton. This variation can be used to formulate the most efficient breeding strategy and to design cotton for a particular environment.
The meaning of leisure for well‐elderly Italians in an Australian community: Implications for occupational therapy
Authors: Pereira Robert B. , Stagnitti Karen
Published: February 2008

Aim: This paper documents a study that aimed to discover the meaning of leisure experiences for an ageing Italian community in a large regional centre in Victoria, Australia.

Methods: This qualitative investigation used a phenomenological study design, and data were collected through semistructured interviews with 10 well‐elderly Australian Italians.

Results: Participants engaged in numerous leisure occupations that were meaningful to them and directly impacted on positive subjective experiences and health outcomes.

Conclusion: This paper adds to an understanding of how leisure impacts on the health of well‐elderly Australians and how occupational therapists can use leisure effectively in interventions for successful ageing.
VASCULAR ANGIOTENSIN AT2RECEPTORS IN HYPERTENSION AND AGEING
Authors: Widdop Robert E , Vinh Antony , Henrion Daniel , Jones Emma S
Published: February 2008

Angiotensin II (Ang II) acts on both subtype 1 receptors (AT1R) and subtype 2 receptors (AT2R). AT1R stimulation mediates all of the classical actions of Ang II including vasoconstriction and cardiovascular hypertrophy. By contrast, AT2R stimulation is thought to exert a counter‐regulatory effect on AT1R and exert direct vasodilatation and antigrowth effects.

In this brief review, the vascular effects of AT2R are reviewed in the context of recent data relating to hypertension and ageing.

In particular the vascular AT2R phenotype in isolated mesenteric arteries may switch from that of relaxation to contraction in hypertension or ageing and this AT2R contractile phenotype can be converted to relaxation, at least with chronic antihypertensive treatment in spontaneously hypertensive rats.

In vivodata pertaining to hypertension and ageing are consistent with vasodilator and antiremodelling effects of AT2R.
CHILDHOOD OBESITY, HYPERTENSION, THE METABOLIC SYNDROME AND ADULT CARDIOVASCULAR DISEASE
Authors: Beilin Lawrence , Huang Rae‐Chi
Published: February 2008

The worldwide epidemic of obesity in adults has been mirrored in children in developed and developing countries.

Central obesity appears to be driving a cluster of abnormalities often referred to as the metabolic syndrome.

The definition of the metabolic syndrome in children is not suited to arbitrary cut‐offs and a definition using the significant clustering of risk factors that is already evident in childhood and adolescent populations may be preferable.

An Australian population study showed that 25% of 8‐year‐olds and 29% of 14‐year‐olds could be described by the high risk cluster with features similar to adult metabolic syndrome.

The high risk cluster was significantly linked to high and low birthweight, shorter duration of breast‐feeding, larger postnatal weight gains after 12 months of age and raised C‐reactive protein, gamma glutamyl transferase and alanine transaminase levels. At‐risk young adults have also been shown to have macroscopic atherosclerosis in post‐mortem studies.

Identification of at‐risk children has obvious benefits for the individual and as well, for prevention of a future cohort with raised cardiovascular morbidity and mortality; however, complexities and controversies exist in doing so. Familial, genetic and lifestyle risk factors aggregate and labelling children with predisease may be problematic. Committed political and societal changes are necessary to reduce childhood obesity and subsequent adult cardiovascular disease.
NEW INSIGHTS INTO THE SYMPATHETIC, ENDOTHELIAL AND CORONARY EFFECTS OF NICOTINE
Authors: Adamopoulos Dionysios , Van De Borne Philippe , Argacha Jean Francois
Published: February 2008

Nicotine is a well studied pleiotropic agent which occurs naturally in tobacco smoke and has been largely accused for many of the adverse effects of smoking on the cardiovascular system, including autonomic imbalance, endothelial dysfunction and coronary blood flow dysregulation.

The acute sympathoexcitatory effects of smoking on the cardiovascular system are partially mediated by catecholamine release, muscle sympathetic nerve excitation and peripheral chemoreceptor sensitivity increase, consecutive to nicotinic receptor stimulation in the autonomic nervous system.

Recent animal data suggest that nicotine promotes the oxidative and inflammatory stress to the endothelium and induces pathological angiogenesis, leading to the progression of the atherosclerotic lesions.

Nicotine increases myocardial work without impairing the physiological coronary vasodilatation. Consequently, nicotine per se cannot explain the sudden reduction in coronary flow reserve after exposure to both active and passive smoking.

Nicotine's biological effects are characterized by a rapid onset of tolerance, which can explain why nicotine administration does not elicit acute coronary and chemoreflex side‐effect in smokers.
Shaken baby syndrome in New Zealand, 2000–2002
Authors: Kelly Patrick , Farrant Bridget
Published: February 2008

Aim:  To describe the epidemiology of subdural haemorrhage (SDH) in New Zealand infants.

Methods:  Prospective enrolment of all cases of infantile SDH from 2000 to 2002. Retrospective analysis of national discharge and death data for the same period.

Results:  Seventy‐seven cases of infantile SDH were identified prospectively, and a further 49 cases retrospectively. Of these 126 cases, 92 resulted from non‐birth‐related trauma. Forty‐eight of these were attributed to abuse and 28 to accidental injury. Sixteen cases were undetermined. The ‘minimum’ annual incidence of inflicted infantile SDH in New Zealand is 14.7 per 100 000 (95% confidence interval(CI) 10.8–19.4), and the ‘maximum’ 19.6 per 100 000 (95% CI 15.1–25.0). Among Maori, the ‘minimum’ is 32.5 per 100 000 (95% CI 21.4–47.3), and the ‘maximum’ 38.5 per 100 000 (95% CI 26.3–54.4).

Conclusions:  The epidemiology of infantile subdural haemorrhage in New Zealand is similar to that described elsewhere. Non‐accidental head injury is a significant child health issue in New Zealand, and the incidence is particularly high among Maori.
Pemphigus vulgaris as a possible cause of protein‐losing gastroenteropathy: A case report
Authors: Ishige Takashi , Kaneko Hiroaki , Suzuki Tomoko , Miyazawa Reiko , Tomomasa Takeshi , Kubota Mitsuru , Morikawa Akihiro
Published: February 2008

Abstract:  We present a case of pemphigus vulgaris (PV) accompanied with protein‐losing gastroenteropathy (PLE). A 9‐year‐old girl developed multiple oral ulcerations and erosions. She was first treated with oral antibiotics and a topical steroid without improvement. Laboratory data showed eosinophilia (absolute eosinophil count 1.08 × 109/L) and hypoproteinemia (total serum protein 3.9 g/dL, albumin 2.2 g/dL). A biopsy specimen from the ileum showed intense eosinophil infiltration and albumin scintigraphy demonstrated protein exduation from the same site. Endoscopic examination of the oesophagus showed multiple ulcerations and erosions, and biopsy specimen showed eosinophilic spongiosis and immunohistologic staining demonstrated deposits of IgG and C3 in the intercellular space. Antidesmoglein‐3 antibody elevated, she was diagnosed as PV complicated with PLE. Immunofluorescence study of a biopsy specimen from the terminal ileum showed no significant immunoglobulin or complement deposition, and autoantibody against intestinal mucosa was unclear in this case. Gastrointestinal evaluations should be considered in patients with hypoproteinemia associated with PV.
Acute pancreatitis: A rare presenting feature of Henoch Schonlein purpura
Authors: Soyer Tutku , Egritas Ödül , Atmaca Emel , Akman Hakkı , Öztürk Haluk , Tezic Tahsin
Published: February 2008

Abstract:  Pancreatitis is a rare manifestation of Henoch Schonlein purpura (HSP). Herein we report a 3‐year‐old girl presented with acute pancreatitis that developed characteristic rash for HSP at the fifth day of clinical onset. Abdominal pain which is the most frequent sign of gastrointestinal involvement can be also explained by acute pancreatitis. Although clinical features of pancreatitis may be encountered after the onset of the typical rash, pancreatitis can also occur as a presenting feature. This rare presentation of HSP is discussed to emphasise the clinical features, presentation and outcome of pancreatic involvement.