bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of aquatic exposure to the insecticide carbaryl are species‐specific across life stages and mediated by heterospecific competitors in anurans
Authors: Distel Christopher A. , Boone Michelle D.
Published: July 2010

1. Understanding the direct and indirect mechanisms by which anthropogenic stressors interact with species and communities is central to understanding ecology in a modern world. Pesticides have been implicated in amphibian declines worldwide, but no mechanism has yet been identified.

2. We tested the hypotheses that exposure to the insecticide carbaryl (2 mg/L) would mediate competitive outcomes between larvae of two anuran species (Bufo americanus, American toads and Rana pipiens, northern leopard frogs), and that post‐exposure effects would carry over to affect juveniles in the terrestrial environment.

3. These hypotheses were tested in controlled mesocosm experiments. Toad survival decreased with insecticide exposure and presence of heterospecific competitors, relative to low‐density controls. However, when exposed to the insecticide, toads experienced the greatest survival when leopard frogs were present. Larval period of toads was lengthened by carbaryl exposure and high density of conspecifics. Leopard frog survival was reduced only by high conspecific density, and larval period was shortened by carbaryl exposure. There were no significant effects of the insecticide on periphyton abundance, although phytoplankton abundance increased and zooplankton abundance decreased after exposure.

4. A subset of metamorphs of each species from each aquatic treatment was added to 2 × 2 m terrestrial enclosures to evaluate larval treatment effects on overwinter survival and growth. Despite differences in initial mass of this subset of metamorphs, mass at spring emergence was not significantly affected by any aquatic treatment for either species. However, leopard frog survival to and mass at spring emergence benefited from larger mass at metamorphosis, while toads appeared unaffected.

5. These results suggest that while tadpoles sharing a habitat may experience reduced survival from competition, the presence of multiple amphibian species may ameliorate the effects of pesticide exposure.

6. More generally, maintaining diversity may benefit ecological communities by reducing the impacts of anthropogenic threats to certain taxa.
Effect of herbage mass and allowance on sward characteristics, milk production, intake and rumen volatile fatty acid concentration
Authors: McEvoy M. , Delaby L. , Murphy J. P. , Boland T. M. , O’Donovan M.
Published: July 2010

The objective of this study was to examine the effect of herbage mass and daily herbage allowance (DHA) on sward characteristics and animal performance, dry‐matter intake, rumen pH and volatile fatty acid production of unsupplemented spring‐calving dairy cows throughout the main grazing season. Sixty‐eight Holstein‐Friesian dairy cows were randomly assigned across four treatments (n = 17) in a 2 × 2 factorial design. Two swards were created with different levels of pre‐grazing herbage mass [allocated above 4 cm (>4 cm); 1700 kg DM ha−1 (medium; M) or 2200 kg DM ha−1 (high; H)] and two levels of DHA (>4 cm; 16 or 20 kg DM per cow d−1). An additional eight lactating ruminally cannulated Holstein–Friesian dairy cows were randomly assigned to each treatment in a replicated 4 × 4 Latin square design. Sward and animal measurements were collected across four periods each of 1 week duration in April and May (PI) and July and August (PII). Maintaining the medium‐mass sward across the season improved the nutritive value of the sward in the latter part of the grazing season compared with high‐mass swards, thus resulting in increased animal intakes and milk production throughout PII. The higher organic matter digestibility of the medium‐compared with high‐masses during PII indicates that grazing severity and herbage mass in the spring to mid‐summer period will determine sward quality parameters in the late summer period.
Experience‐dependent natal philopatry of breeding greater flamingos
Authors: Balkiz Özge , Béchet Arnaud , Rouan Lauriane , Choquet Rémi , Germain Christophe , Amat Juan A. , Rendón‐Martos Manuel , Baccetti Nicola , Nissardi Sergio , Özesmi Uygar , Pradel Roger
Published: July 2010

1. Contrary to the generally high level of natal philopatry (i.e. likelihood that individuals breed at their natal colony) found in first‐breeding colonial birds, little is known of natal philopatry later in life. Most hypotheses advanced to explain natal philopatry are valid at all ages. However, for young and inexperienced birds, the benefits of natal philopatry may be counterbalanced by the costs of intraspecific competition at the natal colony making dispersal temporarily advantageous. In turn, experience may increase competitive ability and make natal philopatry advantageous again.

2. We evaluated this hypothesis on the large‐scale dispersal of greater flamingosPhoenicopterus roseusbreeding among three colonies comprising >85% of the Western Mediterranean metapopulation. The Camargue (France) and Fuente de Piedra (Spain) are large and saturated colonies while Molentargius (Sardinia) is a recent and growing colony.

3. We used a 20‐year capture‐mark‐resighting dataset of 4900 flamingos ringed as chicks in Camargue and Fuente de Piedra and breeding at the three colonies. We assessed the effects of natal colony and breeding experience (first‐time observed breedersversusconfirmed experienced breeders) on dispersal using multistate capture‐recapture models. Dispersal to an unobservable state accounted for temporary emigration.

4. Fidelity was higher at the natal colony (>84%) than elsewhere. Fidelity increased with experience in the two large colonies (Camargue and Fuente de Piedra) suggesting a large‐scale experience‐related despotic distribution. Breeding dispersal was significant (up to 61% and 52% for first‐time breeders and experienced breeders, respectively) so that colony dynamics is affected by exchanges with other colonies. Except for Fuente‐born breeders leaving Molentargius, dispersal to the natal colony was higher than to any other colonies.

5. Survival was not higher at the natal colony. Inexperienced birds likely had lower breeding success at the Camargue and skipped reproduction after having emigrated to the other large colony but not to Molentargius. Breeding at Molentargius could allow avoiding queuing (and non‐breeding) at the large colonies while gaining experience and competitive ability for future attempts.

6 Natal philopatry appears as an important driver of large‐scale breeding dispersal in the Greater flamingo. The fitness advantage of natal philopatry is likely experience‐dependent and mediated by the variations of intraspecific competition.
Synthesizing traditional biogeography with microbial ecology: the importance of dormancy
Authors: Locey Kenneth J.
Published: July 2010

The discovery of biogeographical patterns among microbial communities has led to a focus on the empirical evaluation of the importance of dispersal limitation in microbial biota. As a result, the spatial distribution of microbial diversity has been increasingly studied while the synthesis of biogeographical theory with microbial ecology remains undeveloped. To make biogeographical theory relevant to microbial ecology, microbial traits that potentially affect the distribution of microbial diversity need to be considered. Given that many microorganisms in natural environments are in a state of dormancy and that dormancy is an important microbial fitness trait, I provide a first attempt to account for the effects of dormancy on microbial biogeography by treating dormancy as a fundamental biogeographical response. I discuss the effects of dormancy on the equilibrium theory of island biogeography and on the unified neutral theory of biodiversity and biogeography, and suggest how the equilibrium theory of island biogeography can produce predictions approaching those of the Baas‐Becking hypothesis (i.e. everything is everywhere, but the environment selects). In addition, I present a conceptual model of the unified neutral theory of biodiversity and biogeography, generalized to account for dormancy, from which a full model can be constructed for species with or without dormant life history stages.
Infection of gill and kidney of Fraser River sockeye salmon, Oncorhynchus nerka (Walbaum), by Parvicapsula minibicornis and its effect on host physiology
Authors: Bradford M J , Lovy J , Patterson D A
Published: July 2010

Adult sockeye salmon, Oncorhynchus nerka (Walbaum), migrating upstream in the Fraser River, British Columbia, are exposed to the myxozoan parasite Parvicapsula minibicornis when they enter the river from the ocean. Infections are initially localized in the kidney but have recently been associated with branchitis in one population. Adult fish from five locations in the watershed were sampled to determine whether branchitis was widespread. P. minibicornis infections in kidney glomeruli were prevalent in all samples except for a sample of fish that had just entered the Fraser River from the ocean. For fish captured in spawning streams, parasites were observed in the renal tubules and gill, and branchitis was observed in 70% of fish. Plasma osmolality was negatively correlated with the number of parasites in the kidney tubules, which we hypothesize to be caused by the breach of glomerular membranes as the parasite leaves the fish. Plasma lactate values increased with increasing levels of pathology in gills. These findings support the hypothesis that P. minibicornis impacts the physiology of migrating fish, which may in turn affect the likelihood that adults will be able to migrate and spawn successfully.
Lipoprotein‐associated phospholipase A2 activity and mass in relation to vascular disease and nonvascular mortality
Authors:   Heart Protection Study Collaborative Group
Published: July 2010

Abstract.  Heart Protection Study Collaborative Group (Clinical Trial Service Unit, University of Oxford, Oxford, UK) Lipoprotein‐associated phospholipase A2 activity and mass in relation to vascular disease and nonvascular mortality. J Intern Med 2010; 268:348–358.

Objectives.  To assess whether associations of circulating lipoprotein‐associated phospholipase A2 (Lp‐PLA2) with vascular disease are independent of other risk factors.

Methods.  Lp‐PLA2 activity and mass, lipids and other characteristics were measured at baseline in 19 037 individuals at high risk of vascular disease in a randomized trial of simvastatin with 5‐year average follow‐up.

Results.  Lp‐PLA2 activity and mass were correlated with each other (r = 0.56), lipids and other vascular risk factors. The moderate association of Lp‐PLA2 activity with occlusive coronary events (n = 2531) in analyses adjusted for nonlipid factors (hazard ratio per 1 SD [HR] 1.11, 95% CI 1.06–1.15) became nonsignificant after further adjustment for apolipoproteins (HR 1.02, 0.97–1.06). Such adjustment also attenuated HRs with Lp‐PLA2 mass from 1.08 (1.03–1.12) to 1.05 (1.01–1.09). By contrast, the HR with apolipoprotein‐B100 of 1.15 (1.10–1.19) was only slightly attenuated to 1.14 (1.09–1.19) after further adjustment for apolipoprotein A1 and Lp‐PLA2. Age‐ and sex‐adjusted HRs for other cardiac events (n = 1007) with either Lp‐PLA2 activity or mass were about 1.20, but HRs reduced after adjustment for nonlipid factors (activity: 1.11, 1.04–1.18; mass: 1.08, 1.02–1.15). Adjusted HRs for ischaemic stroke (n = 900) were weak and nonsignificant and for nonvascular mortality (n = 1040) were 1.01 (0.94–1.09) with activity and 1.12 (1.05–1.19) with mass. Simvastatin reduced Lp‐PLA2 levels by about one‐quarter, but simvastatin’s vascular protection did not vary with baseline Lp‐PLA2 concentration.

Conclusions.  Associations of Lp‐PLA2 with occlusive coronary events depend considerably on lipid levels, whereas those with other cardiac events appear to reflect confounding from cardiovascular medication and prior vascular disease.
Accuracy and surgical feasibility of a CBCT‐based stereolithographic surgical guide aiding autotransplantation of teeth: in vitro validation
Authors: SHAHBAZIAN M. , JACOBS R. , WYATT J. , WILLEMS G. , PATTIJN V. , DHOORE E. , VAN LIERDE C. , VINCKIER F.
Published: July 2010

Summary  The aims of this study were to determine the accuracy of a 3D computer model and stereolithographic (STL) replica when compared to the real tooth and to develop a cone beam computed tomography (CBCT)‐based planning technique including surgical guide fabrication. A STL surgical guide and a tooth replica were fabricated using SimPlant Pro 12.1. To validate this process, tooth segmentation and replica design were prepared for comparison to an optical scan of the corresponding tooth. For surgical intervention, a dry dentate mandible was scanned using a Scanora CBCT and the donor tooth was segmented. The donor tooth was repositioned, and two guides were designed. These tooth replica and guides were used in socket preparation of the dry mandible. The 3D computer model of the segmented teeth and related STL models showed satisfactory results with an acceptable accuracy. The surfaces were within 0·25 mm distance, but in some areas up to 2·5 mm deviation were seen. The results showed that 79% of the points was between 0·25 and −0·25 mm, 3% was overestimated (>0·25 mm) and 18% was underestimated (<−0·25 mm). The computer‐based repositioning of the donor tooth and construction of tooth replica and guide allowed socket preparation before donor tooth extraction and optimization of the STL procedure for in vivo planning of CBCT‐based autotransplantation.
Utility of computer simulations in landscape genetics
Authors: EPPERSON BRYAN K. , MCRAE BRAD H. , SCRIBNER KIM , CUSHMAN SAMUEL A. , ROSENBERG MICHAEL S. , FORTIN MARIE‐JOSÉE , JAMES PATRICK M. A. , MURPHY MELANIE , MANEL STÉPHANIE , LEGENDRE PIERRE , DALE MARK R. T.
Published: July 2010

Population genetics theory is primarily based on mathematical models in which spatial complexity and temporal variability are largely ignored. In contrast, the field of landscape genetics expressly focuses on how population genetic processes are affected by complex spatial and temporal environmental heterogeneity. It is spatially explicit and relates patterns to processes by combining complex and realistic life histories, behaviours, landscape features and genetic data. Central to landscape genetics is the connection of spatial patterns of genetic variation to the usually highly stochastic space–time processes that create them over both historical and contemporary time periods. The field should benefit from a shift to computer simulation approaches, which enable incorporation of demographic and environmental stochasticity. A key role of simulations is to show how demographic processes such as dispersal or reproduction interact with landscape features to affect probability of site occupancy, population size, and gene flow, which in turn determine spatial genetic structure. Simulations could also be used to compare various statistical methods and determine which have correct type I error or the highest statistical power to correctly identify spatio‐temporal and environmental effects. Simulations may also help in evaluating how specific spatial metrics may be used to project future genetic trends. This article summarizes some of the fundamental aspects of spatial–temporal population genetic processes. It discusses the potential use of simulations to determine how various spatial metrics can be rigorously employed to identify features of interest, including contrasting locus‐specific spatial patterns due to micro‐scale environmental selection.
FasR, a novel class of transcriptional regulator, governs the activation of fatty acid biosynthesis genes in Streptomyces coelicolor
Authors: Arabolaza Ana , D'Angelo Matilde , Comba Santiago , Gramajo Hugo
Published: July 2010

Membrane lipid homeostasis is essential for bacterial survival and adaptation to different environments. The regulation of fatty acid biosynthesis is therefore crucial for maintaining the correct composition and biophysical properties of cell membranes. This regulation implicates a biochemical control of key enzymes and a transcriptional regulation of genes involved in lipid metabolism. In Streptomyces coelicolor we found that control of lipid homeostasis is accomplished, at least in part, through the transcriptional regulation of fatty acid biosynthetic genes. A novel transcription factor, FasR (SCO2386), controls expression of fabDHPF operon and lies immediately upstream of fabD, in a cluster of genes that is highly conserved within actinomycetes. Disruption of fasR resulted in a mutant strain, with severe growth defects and a delay in the timing of morphological and physiological differentiation. Expression of fab genes was downregulated in the fasR mutant, indicating a role for this transcription factor as an activator. Consequently, the mutant showed a significant drop in fatty acid synthase activity and triacylglyceride accumulation. FasR binds specifically to a DNA sequence containing fabDHPF promoter region, both in vivo and in vitro. These data provide the first example of positive regulation of genes encoding core proteins of saturated fatty acid synthase complex.
Modulation of amoebic hepatic abscess by the parasympathetic system
Authors: MUÑOZ‐ORTEGA M. , QUINTANAR‐STEPHANO A. , GARCÍA LORENZANA M. , CAMPOS‐ESPARZA M. R. , SILVA‐BRIANO M. , ADABACHE‐ORTÍZ A. , CAMPOS‐RODRÍGUEZ R. , RODRÍGUEZ M. G. , VENTURA‐JUÁREZ J.
Published: July 2010

The neuro‐immune network, in which the vagus nerve is involved, provides feedback between its afferent branches for signalling central nervous system from sites of injury through cytokines and its efferent branches, which release acetylcholine, an anti‐inflammatory neurotransmitter. For gain insight into the parasympathetic mechanisms participating in the inflammatory response in the liver, we studied the effects of a vagotomy on the innate immune response in hamsters with amoebic liver abscess. At 7 days post‐infection, compared to the control, liver parasympathectomy resulted in a larger abscess size, a greater production of collagen fibres, fewer trophozoites, increased serum levels of IL‐10 and IFN‐γ and increased numbers of IL‐10 and IFN‐γ‐positive cells in situ, with no change in the number of macrophages and NK cells. Data indicate that the vagotomy disrupted the inflammatory response, causing an increase in the response against infection, then could favour the innervation of the liver by the sympathetic nervous system and would then take the control of the immune response by stimulating the conversion of macrophages to epithelioid cells; and through increased IL‐10 production would induce the hepatic stellar cells to become myofibroblast collagen producer cells, thus forming a barrier of collagen and blocking trophozoite migration.
Elevated CO2 shifts the focus of tobacco plant defences from cucumber mosaic virus to the green peach aphid
Authors: FU XUE , YE LEFU , KANG LE , GE FENG
Published: July 2010

Elevation in CO2 concentration broadly impacts plant physiological characteristics, which influences herbivores and biotrophic pathogens, which in turn regulate the plant defensive response. In this study, responses of tobacco plants to stress in the form of the green peach aphid, Myzus persicae (Sulzer), or cucumber mosaic virus (CMV), or both aphid and CMV combined were investigated in open‐top chambers under ambient and elevated CO2 concentrations. We measured aboveground biomass and foliar chlorophyll, nitrogen, non‐structural carbohydrates, soluble protein, total amino acid and nicotine content in tobacco plants and also measured aphid population dynamics, body weight, honeydew production and anti‐oxidative enzyme activities in individual aphids. Plants produced more secondary metabolites for defence in both CO2 treatments when treated with aphid and CMV combined than with either alone. Aphid density significantly increased on CMV‐infected tobacco plants (relative to uninfected plants) under ambient CO2 but not under elevated CO2. This suggests that plant defences against virus and aphid would be more efficient under elevated CO2. Plant defence appears to shift from plant virus to aphid under increasing CO2 levels, which highlights the potential influences of multiple biotic stressors on plants under elevated CO2.
Flower development in the passion fruit Passiflora edulis requires a photoperiod‐induced systemic graft‐transmissible signal
Authors: NAVE NAHUM , KATZ EHUD , CHAYUT NOAM , GAZIT SHMUEL , SAMACH ALON
Published: July 2010

Different organisms use gradual seasonal changes in photoperiod to correctly time diverse developmental processes, such as transition to flowering in plants. Florigen is a systemic signal formed in leaves exposed to specific environmental cues, mainly photoperiodic, and capable of triggering flower induction in several species. Here we show that in Passiflora edulis, a perennial climbing vine, flower initiation occurs throughout the year; however, without long photoperiods, flower primordia show arrested growth and differentiation at an early stage. Our results support the existence of a positive, systemic, graft‐transmissible signal, produced in mature leaves under LDs, that is required for normal flower development beyond sepal formation. Our results also suggest that Gibberellin acts to inhibit flower development. We provide evidence for genetic variation in the response to short photoperiods. A genotype capable of forming developed flowers under short photoperiods produces a positive graft transmissible signal allowing normal flower development under short days in a cultivar which normally aborts flower development under these conditions. We believe these findings contribute towards discovering the chemical nature of this interesting mobile signal involved in flower development.
Variability of the L‐Histidine decarboxylase gene in allergic rhinitis
Authors: Gervasini G. , Agúndez J. A. G. , García‐Menaya J. , Martínez C. , Cordobés C. , Ayuso P. , Cornejo J. A. , Blanca M. , García‐Martín E.
Published: July 2010

To cite this article: Gervasini G, Agúndez JAG, García‐Menaya J, Martínez C, Cordobés C, Ayuso P, Cornejo JA, Blanca M, García‐Martín E. Variability of the L‐Histidine decarboxylase gene in allergic rhinitis. Allergy 2010; 65: 1576–1584.

Background:  Nonsynonymous polymorphisms in genes coding for histamine‐metabolizing enzymes, diamine oxidase and histamine N‐methyltransferase are related to the risk of developing allergic diseases. The role of polymorphisms in the histidine decarboxylase gene remains unexplored. The objective of this study is to identify novel polymorphisms in the human histidine decarboxylase gene and to analyse the clinical association of nonsynonymous polymorphisms with rhinitis.

Methods:  We performed a single‐strand conformational polymorphism analysis of the histidine decarboxylase gene sequence. The presence of two nonsynonymous polymorphisms Thr31Met (rs17740607) and Glu644Asp (rs2073440) was analysed in 442 unrelated patients with allergic rhinitis, 233 of whom also had asthma, and in 486 healthy subjects.

Results:  We observed three novel polymorphisms designated as ss50402829, ss50402830 and ss50402831‐(rs17740607) with allele frequencies = 0.005, 0.208 and 0.073, respectively. Statistically significant differences were observed for the histidine decarboxylase Glu644Asp (rs2073440) polymorphism, with OR (95% CI) values for homozygous carriers of the Glu644 allele equal to 3.12 (1.75–5.56, P < 0.00005) for all patients, 3.38 (1.54–7.44, P = 0.002) for patients with rhinitis alone, and 2.92 (1.43–5.95), P = 0.003 for patients with rhinitis + asthma, when compared with healthy controls. A significant Glu644 gene–dose effect was observed for overall patients (P = 0.0001), for patients with rhinitis alone (P = 0.005) and for patients with rhinitis + asthma (P = 0.010).

Conclusions:  The HDC allele Glu644 in homozygosity increases the risk of developing rhinitis in the studied population. This adds to increasing evidence supporting a prominent role of genetic variations related to histamine homeostasis in the risk to develop allergic diseases.
Don't change that (calcium) channel: mutations in the same calcium channel gene can cause multiple distinct phenotypes
Authors: Sawkins JN
Published: July 2010

Scapuloperoneal spinal muscular atrophy and CMT2C are allelic disorders caused by alterations in TRPV4

Deng et al. (2010)

Nature Genetics 42(2):165–169

Mutations in TRPV4 cause Charcot–Marie–Tooth disease type 2C

Landouré et al. (2010)

Nature Genetics 42(2):170–174

Alterations in the ankyrin domain of TRPV4 cause congenital distal SMA, scapuloperoneal SMA and HMSN2C

Auer‐Grumbach et al. (2010)

Nature Genetics 42(2):160–164
Hippocampus development and function: role of epigenetic factors and implications for cognitive disease
Authors: Lagali PS , Corcoran CP , Picketts DJ
Published: July 2010

Lagali PS, Corcoran CP, Picketts DJ. Hippocampus development and function: role of epigenetic factors and implications for cognitive disease.

The hippocampus is a primary region of the brain controlling the formation of memories and learned behaviours. The ability to learn or form a memory requires a neuron to translate a transient signal into gene expression changes that have a long‐lasting effect on synapse activity and connectivity. Numerous studies over the past decade have detailed changes in epigenetic modifications under various learning paradigms to support a role for chromatin remodelling in these processes. Moreover, the identification of mutations in epigenetic regulators as the cause of mental retardation or intellectual disability (MR/ID) disorders further strengthens their importance to learning and memory. Animal models for many of these disorders are emerging and advancing our understanding of the molecular mechanisms linking epigenetic regulation and cognitive function. Here, we review how chromatin remodelling proteins implicated in MR/ID contribute to the development of the hippocampus and memory formation.
Attitude toward xenotransplantation of patients prior and after human organ transplantation
Authors: Stadlbauer V. , Stiegler P. , Müller S. , Schweiger M. , Sereingg M. , Tscheliessnigg K.H. , Freidl W.
Published: July 2010

Stadlbauer V, Stiegler P, Müller S, Schweiger M, Sereingg M, Tscheliessnigg KH, Freidl W. Attitude toward xenotransplantation of patients prior and after human organ transplantation. Clin Transplant 2011: 25: 495–503. © 2010 John Wiley & Sons A/S.

Abstract: Xenotransplantation is a potential strategy to overcome the shortage of human donor organs. As this technique has a major medical and psychological impact on patients and their family and friends, the attitude of patients currently waiting for organ transplantation is important. Therefore, we conducted a survey on the attitude toward xenotransplantation of patients on the waiting list and already transplanted patients. Patients received detailed information before being asked to fill in the questionnaire. We found that 65% would accept xenotransplantation, irrespective of gender, education level or if the patients were on the waiting list or already transplanted. The most common concern was transmission of diseases or genetic material, followed by psychological concerns and ethical issues. More patients had a positive attitude toward accepting cell or tissue transplantation when compared to whole organs. Pig pancreas islet cell transplantation is generally well accepted, patients with diabetes mellitus show even higher acceptance rates than patients without diabetes. In conclusion, xenotransplantation seems to be well accepted in patients who are potential future candidates for organ transplantation. Informing patients about the current status of research tended to decrease acceptance rates slightly.
Differential effects of sevoflurane and propofol anesthesia on left ventricular–arterial coupling in dogs
Authors: DERYCK Y. L. J. M. , FONCK K. , DE BAERDEMAEKER L. , NAEIJE R. , BRIMIOULLE S.
Published: July 2010

Background:General anesthetics interfere with arterial and ventricular mechanical properties, often altering left ventricular–arterial (LVA) coupling. We hypothesized that sevoflurane and propofol alter LVA coupling by different effects on arterial and ventricular properties.

Methods:Experiments were conducted in six anesthetized open‐chest dogs for the measurement of left ventricular pressure and aortic pressure and flow. Measurements were performed during anesthesia with 0.5, 1.0 and 1.5 minimum alveolar concentration sevoflurane and 12, 24 and 36 mg/kg/h propofol. LVA coupling was assessed as the ratio of ventricular end‐systolic elastance (Ees, measuring ventricular contractility) to effective arterial elastance (Ea, measuring ventricular afterload). The steady component of afterload, arterial tone, was assessed by systemic vascular resistance and arterial pressure–flow curves. The pulsatile component of afterload was assessed by aortic impedance and compliance.

Results:Sevoflurane decreased aortic pressure and cardiac output more than propofol. Sevoflurane reduced arterial tone, increased arterial stiffness and did not affect wave reflections. It increasedEa, decreasedEesand reduced LVA coupling. Propofol reduced arterial tone, did not affect arterial stiffness and decreased wave reflections. It did not affectEa,Eesor LVA coupling.

Conclusions:Sevoflurane increased ventricular afterload and decreased ventricular performance, thereby altering LVA coupling. Propofol did not affect ventricular afterload or ventricular performance, thereby preserving LVA coupling. Thus, propofol preserves LVA coupling in dogs better, and might be a better choice for patients with compromised left ventricular function.
Orexigenic effect of cocaine‐ and amphetamine‐regulated transcript (CART) after injection into hypothalamic nuclei in streptozotocin‐diabetic rats
Authors: Hou Jun , Zheng De‐Zhi , Zhou Ji‐Yin , Zhou Shi‐Wen
Published: July 2010

1. The aim of the present study was to investigate the orexigenic effect of cocaine‐ and amphetamine‐regulated transcript (CART) peptide on feeding regulation following its injection into discrete nuclei of the hypothalamus.

2. Male Sprague‐Dawley diabetic rats were injected with 0.06 or 0.2 nmol CART (55–102) or an equal volume of saline into various hypothalamic areas and food intake was then measured 1, 2, 4, 8 and 24 h after injection. Changes in hypothalamic CART mRNA expression in response to dietary intervention (2 weeks feeding of a high‐fat diet) were assessed using quantitative real‐time reverse transcription–polymerase chain reaction. Possible interactions between neuropeptide Y (NPY), agouti‐related protein (AGRP), α‐melanocyte‐stimulating hormone (MSH) and corticotropin‐releasing hormone (CRH) were evaluated in an in vitro hypothalamic explant system. Neuropeptide immunoreactivities (IR) were detertmined using radioimmunassays (RIAs).

3. At 0.2 nmol, CART (55–102) significantly increased feeding in fasted diabetic rats after injection into the dorsomedial hypothalamic nucleus and arcuate nucleus (ARC). Injection of 0.2 nmol CART (55–102) into the ARC of satiated diabetic rats also increased food intake that was similar in both magnitude and time‐course to the response seen in fasted diabetic rats. Food intake in diabetic rats on a high‐fat diet was clearly increased after injection of 0.2 nmol CART (55–102) into the ARC, as was CART mRNA expression. Incubation of hypothalamic explants with 0.4, 4 and 40 nmol/L CART (55–102) for 45 min significantly increased NPY IR, whereas exposure of explants to 4 nmol/L CART (55–102) increaesd AGRP IR and CRH IR. None of the concentrations of CART (55–102) tested had any effect on α‐MSH IR.

4. Together, these data provide further evidence that hypothalamic CART has an orexigenic effect, which, in the ARC, may stimulate the release of hypothalamic orexigenic neuropeptides.
Pathology of combined hepatocellular‐cholangiocarcinoma
Authors: Yeh Matthew M
Published: July 2010

Combined hepatocellular‐cholangiocarcinoma is a rare primary neoplasm in the liver. It has gained increasing recognition recently, which in part may be due to more extensive sampling of the explants and surgical resection specimens, the diagnostic challenges encountered in the clinical practice, and the yet to be determined clinical outcome, but partly may be attributed to its intriguing histogenesis/cells of origin. This review aims to update combined hepatocellular‐cholangiocarcinoma with an emphasis on the pathological diagnosis, including the differential diagnosis and its diagnostic pitfalls, the possible cell of origin of this neoplasm, and its clinical outcome.
Parents' perspectives to childhood fever: Comparison of culturally diverse populations
Authors: Erkek Nilgun , Senel Saliha , Sahin Murat , Ozgur Ozlem , Karacan Candemir
Published: July 2010

Aim:  To reveal the perceptions, knowledge and practices of our parents regarding children's fever and to discuss the differences between other populations.

Methods:  Parents of 200 febrile children aged 0–16 years were interviewed between October and November 2007 in the Pediatric Emergency Department at Dr Sami Ulus Children's Health and Diseases Training and Research Hospital. Questions about socio‐demographical data, children's previous history about fever, parental beliefs and practices concerning fever were asked.

Results:  Of the parents, 56.5% stated that fever could be determined by touching the forehead. Of the parents, 43.5% determined children's fever by using thermometer. Only 27.5% of parents knew the correct temperature for fever. Mercury‐in‐glass thermometer was the preferred one to measure children's fever. The preferred route of measuring temperature was the axillary site. Maternal educational level was significantly associated with knowledge on correct definition of fever and proper use of thermometer (P < 0.05) in accordance with the literature. If fever was untreated, of the parents, 84% believed febrile convulsions occur and 10.5% believed brain damage occur if fever was untreated. Parental age, parental educational status, parental knowledge about fever, median number of children in family and children's previous febrile convulsion history did not significantly effect parents' interventions and beliefs about fever (P > 0.05), corroborating the findings of studies from different populations.

Conclusion:  Parental education about ‘fever in childhood’ in our population may positively effect parental knowledge and approach to fever. However, parental education may not be effective in removing parental fear of fever in our population.
Health service delivery for newly arrived refugee children: A framework for good practice
Authors: Woodland Lisa , Burgner David , Paxton Georgia , Zwi Karen
Published: July 2010

Aim:  To propose a framework for good practice to promote improved access, equity and quality of care in service delivery for newly arrived refugee children.

Methods:  Development of a framework based on national and international literature and current service models in Australian paediatric refugee health.

Results:  Ten elements of a framework for good practice were identified: comprehensive health screening; coordination of initial and ongoing health care; integration of physical, developmental and psychological health care; consumer participation; culturally and linguistically appropriate service provision; inter‐sectoral collaboration; accessible and affordable services and treatments; data collection and evaluation to inform evidence‐based practice; capacity building and sustainability; and advocacy.

Conclusions:  High‐quality care can be achieved through a range of service models. The elements identified provide a framework for evaluating current services and for planning future service development. The framework for good practice can be applied to facilitate improvements in refugee health care and to reduce the gap between health needs and currently available services.
The challenges of prompt identification and resuscitation in children with acute fulminant myocarditis: case series and review of the literature
Authors: Ramachandra Geethanjali , Shields Lynn , Brown Katherine , Ramnarayan Padmanabhan
Published: July 2010

Aim:  To describe the clinical presentation, triage, resuscitation and outcome of acute fulminant myocarditis in children presenting to district hospitals and referred for cardiac intensive care.

Methods:  Case series describing five patients (from 2 weeks to 12 years old) with a diagnosis of acute fulminant myocarditis, presented to outlying hospitals between December 2006 and December 2007 and retrieved to a cardiac intensive care unit.

Results:  All children were admitted with non‐specific symptoms such as vomiting, cough and poor feeding to their local hospital, where various provisional diagnoses such as viral gastroenteritis, bronchitis or renal failure were considered. Acute physiological deterioration usually prompted the referral for intensive care. Two children died at the referring hospital during stabilisation by the retrieval team. Three children survived transport to intensive care and to hospital discharge; two received mechanical support and one underwent urgent orthotopic heart transplantation. Enterovirus and parvovirus were identified as causative agents in two patients. In one case, macrophage activation syndrome was diagnosed although no clear viral trigger was identified. Median length of hospitalisation among survivors was 33 days, and mechanical cardiac support was required for a median of 12 days.

Conclusions:  The diagnosis and initial management of acute fulminant myocarditis is extremely challenging. Prognosis for patients admitted to a cardiac centre for early mechanical support can be very favourable, while a delay in considering the diagnosis may result in poor outcome. The diagnosis of myocarditis should be considered in any previously well child presenting with a viral prodrome and non‐specific organ dysfunction associated with dysrhythmias, shock or acute heart failure, even in the absence of cardiomegaly.
Investigation of suspected Guillain–Barre syndrome in childhood: What is the role for gadolinium enhanced magnetic resonance imaging of the spine?
Authors: Smith Nicholas , Pereira John , Grattan‐Smith Padraic
Published: July 2010

Aim:  To review the role of gadolinium‐enhanced magnetic resonance imaging of the spine in the diagnosis of paediatric Guillain–Barre syndrome and compare it with nerve conduction studies and cerebrospinal fluid analysis.

Methods:  A retrospective review of investigations undertaken in children admitted to our institution with acute Guillain–Barre syndrome over a 10‐year period was performed.

Results:  Seven of eight children (88%) displayed post‐gadolinium nerve root enhancement consistent with Guillain–Barre syndrome. This compared with supportive nerve conduction studies in 21/24 children (88%) and cerebrospinal fluid protein analysis consistent with the diagnosis in 16/20 children (80%).

Conclusion:  Nerve conduction studies are the recognised ‘gold standard’ technique for confirming a clinical diagnosis of Guillain–Barre syndrome. In this study, a high positive rate was demonstrated. While more experience is necessary, this study and the literature support gadolinium enhanced magnetic resonance imaging of the spine as a valuable, although not necessarily superior, investigation in the diagnosis of Guillain–Barre syndrome. It may be of particular benefit when specialist neurophysiology expertise is unavailable.
Late toxicity after conformal and intensity‐modulated radiation therapy for prostate cancer: Impact of previous surgery for benign prostatic hyperplasia
Authors: Odrazka Karel , Dolezel Martin , Vanasek Jaroslav , Vaculikova Miloslava , Zouhar Milan , Sefrova Jana , Paluska Petr , Vosmik Milan , Kohlova Tereza , Kolarova Iveta , Navratil Pavel , Brodak Milos , Prosvic Petr , Hoffmann Petr
Published: July 2010

Objectives:  To retrospectively compare late toxicity of conventional‐dose three‐dimensional conformal radiation therapy (3D‐CRT) and high‐dose intensity‐modulated radiation therapy (IMRT) for prostate cancer.

Methods:  A total of 340 patients with T1‐3 prostate cancer were treated with 3D‐CRT (n = 228) and IMRT (n = 112). The median follow‐up time was 5.9 years and 3.0 years, respectively. The prescription dose was 70 Gy for 3D‐CRT and 78 Gy for IMRT. Late gastrointestinal (GI) and genitourinary (GU) toxicities were graded according to the Fox Chase modification of the Radiation Therapy Oncology Group and Late Effects Normal Tissue Task Force criteria.

Results:  There was no difference between 3D‐CRT and IMRT in the incidence of GI and GU toxicity at 3 years. On multivariate analysis, transurethral resection of prostate/open transvesical prostatectomy (TURP/TVPE) for benign prostatic hyperplasia, carried out before radiotherapy, significantly increased the risk of Grade ≥2 GU toxicity (risk ratio 1.88). Among patients who experienced TURP/TVPE, the 5‐year actuarial likelihood of Grade 2–3 urinary incontinence was 23%, compared with 9% for those without prostate surgery (P = 0.01).

Conclusions:  Tolerance of 3D‐CRT and IMRT was similar, despite the use of high radiation dose with IMRT. Previous TURP/TVPE increased the risk of GU toxicity.
Drugs of abuse and stress impair LTP at inhibitory synapses in the ventral tegmental area
Authors: Niehaus Jason L. , Murali Manjari , Kauer Julie A.
Published: July 2010

Synaptic plasticity in the ventral tegmental area (VTA) is modulated by drugs of abuse and stress and is hypothesized to contribute to specific aspects of addiction. Both excitatory and inhibitory synapses on dopamine neurons in the VTA are capable of undergoing long‐term changes in synaptic strength. While the strengthening or weakening of excitatory synapses in the VTA has been widely examined, the role of inhibitory synaptic plasticity in brain reward circuitry is less established. Here, we investigated the effects of drugs of abuse, as well as acute stress, on long‐term potentiation of GABAergic synapses onto VTA dopamine neurons (LTPGABA). Morphine (10 mg/kg i.p.) reduced the ability of inhibitory synapses in midbrain slices to express LTPGABAboth at 2 and 24 h after drug exposure but not after 5 days. Cocaine (15 mg/kg i.p.) impaired LTPGABA24 h after exposure, but not at 2 h. Nicotine (0.5 mg/kg i.p.) impaired LTPGABA2 h after exposure, but not after 24 h. Furthermore, LTPGABAwas completely blocked 24 h following brief exposure to a stressful stimulus, a forced swim task. Our data suggest that drugs of abuse and stress trigger a common modification to inhibitory plasticity, synergizing with their collective effect at excitatory synapses. Together, the net effect of addictive substances or stress is expected to increase excitability of VTA dopamine neurons, potentially contributing to the early stages of addiction.
Glutamate‐induced alterations in Ca2+ signaling are modulated by mitochondrial Ca2+ handling capacity in brain slices of R6/1 transgenic mice
Authors: Rosenstock T. R. , Bertoncini C. R. A. , Teles A. V. , Hirata H. , Fernandes M. J. S. , Smaili S. S.
Published: July 2010

Huntington’s disease is a neurodegenerative disorder caused by an expansion of CAGs repeats and characterized by alterations in mitochondrial functions. Although changes in Ca2+ handling have been suggested, the mechanisms involved are not completely understood. The aim of this study was to investigate the possible alterations in Ca2+ handling capacity and the relationship with mitochondrial dysfunction evaluated by NAD(P)H fluorescence, reactive oxygen species levels, mitochondrial membrane potential (ΔΨm) measurements and respiration in whole brain slices from R6/1 mice of different ages, evaluated in situ by real‐time real‐space microscopy. We show that the cortex and striatum of the 9‐month‐old R6/1 transgenic mice present a significant sustained increase in cytosolic Ca2+ induced by glutamate (Glu). This difference in Glu response was partially reduced in R6/1 when in the absence of extracellular Ca2+, indicating that N‐methyl‐d‐aspartate receptors participation in this response is more important in transgenic mice. In addition, Glu also lead to a decrease in NAD(P)H fluorescence, a loss in ΔΨm and a further increase in respiration, which may have evoked a decrease in mitochondrial Ca2+ () uptake capacity. Taken together, these results show that alterations in Ca2+ homeostasis in transgenic mice are associated with a decrease in uptake mechanism with a diminished Ca2+ handling ability that ultimately causes dysfunctions and worsening of the neurodegenerative and the disease processes.
Functional heterogeneity of NMDA receptors in rat substantia nigra pars compacta and reticulata neurones
Authors: Suárez F. , Zhao Q. , Monaghan D. T. , Jane D. E. , Jones S. , Gibb A. J.
Published: July 2010

The nigra substantia nigra pars compacta (SNc) and substantia pars reticulata (SNr) form two major basal ganglia components with different functional roles. SNc dopaminergic (DA) neurones are vulnerable to cell death in Parkinson’s disease, and NMDA receptor activation is a potential contributing mechanism. We have investigated the sensitivity of whole‐cell and synaptic NMDA responses to intracellular ATP and GTP application in the SNc and SNr from rats on postnatal day (P) 7 and P28. Both NMDA current density (pA/pF) and desensitization to prolonged or repeated NMDA application were greater in the SNr than in the SNc. When ATP levels were not supplemented, responses to prolonged NMDA administration desensitized in P7 SNc DA neurones but not at P28. At P28, SNr neurones desensitized more than SNc neurones, with or without added ATP. Responses to brief NMDA applications and synaptic NMDA currents were not sensitive to inclusion of ATP in the pipette solution. To investigate these differences between the SNc and SNr, NR2 subunit‐selective antagonists were tested. NMDA currents were inhibited by ifenprodil (10 μm) and UBP141 (4 μm), but not by Zn2+(100 nm), in both the SNr and SNc, suggesting that SNc and SNr neurones express similar receptor subunits; NR2B and NR2D, but not NR2A. The different NMDA response properties in the SNc and SNr may be caused by differences in receptor modulation and/or trafficking. The vulnerability of SNc DA neurones to cell death is not correlated with NMDA current density or receptor subtypes, but could in part be related to inadequate NMDA receptor desensitization.
Cerebellar Golgi cells in the rat receive convergent peripheral inputs via a lateral reticular nucleus relay
Authors: Xu Wei , Edgley Steve A.
Published: July 2010

Golgi cells are important players in the function of the cerebellar cortex, controlling the flow of incoming information from mossy fibres to the granule cells, which excite other cortical neurons. We recently showed that in anaesthetized rats most Golgi cells respond to stimulation of afferents from a very wide peripheral receptive field with a long‐lasting depression of firing. These responses are mediated via a crossed ascending afferent pathway but the supraspinal part of this pathway is unknown. Here we have examined the hypothesis that the lateral reticular nucleus, a brainstem nucleus with known broad afferent convergence that projects mossy fibres to much of the cerebellum, is involved. First, we showed that single‐pulse electrical microstimulation within the lateral reticular nucleus can elicit long‐lasting depressions in Golgi cells, which are qualitatively similar to those evoked by peripheral afferent stimulation. Second, we showed that the amplitude of the depressions of Golgi cell firing evoked by peripheral stimulation can be reduced by pharmacological manipulation of the lateral reticular nucleus, either ipsilateral or contralateral to the stimulus site, with local injections of either the GABAA receptor agonist muscimol or the AMPA receptor blocker 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione. This evidence suggests that the lateral reticular nucleus is a relay nucleus in the brainstem for peripheral afferent information in a pathway that generates Golgi cell long‐lasting depression responses.