bluuebunny/crossref_metadata_2025 huggingface dataset:
Song perception among incipient species as a mechanism for reproductive isolation
Authors: BRAMBILLA M. , JANNI O. , GUIDALI F. , SORACE A.
Published: March 2008

Many functions in behavioural processes of small passerines are regulated via vocal messages. Song plays an important role in the development of reproductive barriers and thus playback experiments can often be used for investigating the potential for reproductive isolation through behavioural mechanisms. Moltoni’s warbler Sylvia (cantillans) moltonii is characterized by diagnostic vocalizations and a peculiar pattern of distribution, being parapatric and partly sympatric with the nominate Sylvia c. cantillans. With this work, we test whether these two closely related taxa react equally to their own song and to the song of the other taxon, shedding light on whether they perceive each other’s songs as coming from the same species. We carried out 184 playback experiments within the mainland range of the two forms. We judged the response of the bird on a scale of scores. Each taxon responded more strongly to playback when faced with the song of its own taxon. This held true when applied only to males or females. Additionally, birds tested for both songs showed a stronger response to the song of their own taxon. The distributional context (sympatry vs. allopatry) did not affect bird response. Results indicate that a certain degree of reproductive isolation between the two taxa (because of diverged mate recognition systems) already exists; consistently with genetic data and with the peculiar pattern of distribution; this suggests that the two taxa have reached species status.
A hybrid zone with coincident clines for autosomal and sex‐specific markers in theSorex araneusgroup
Authors: YANNIC G. , BASSET P. , HAUSSER J.
Published: March 2008

In hybrid zones, endogenous counter‐selection of hybrids is usually first expressed as reduced fertility or viability in hybrids of the heterogametic sex, a mechanism known as Haldane’s rule. This phenomenon often leads to a differential of gene flow between sex‐linked markers. Here, we address the possibility of a differential gene flow for Y chromosome, mtDNA and autosomal markers across the hybrid zone between the genetically and chromosomally well‐differentiated speciesSorex antinoriiandSorex araneusrace Vaud. Intermarker comparison clearly revealed coincidental centre and very abrupt clines for all three types of markers. The overall level of genetic differentiation between the two species must be strong enough to hinder asymmetric introgression. Cyto‐nuclear mismatches were also observed in the centre of hybrid zone. The significantly lower number of mismatches observed in males than in females possibly results from Y chromosome–mtDNA interactions. Results are compared with those previously reported in another hybrid zone betweenS. antinoriandS. araneusrace Cordon.
Effectiveness and safety of tranexamic acid administration during total knee arthroplasty
Authors: Lozano M. , Basora M. , Peidro L. , Merino I. , Segur J. M. , Pereira A. , Salazar F. , Cid J. , Lozano L. , Mazzara R. , Macule F.
Published: March 2008

Background  The administration of tranexamic acid (TA) is associated with a decrease in the number of red blood cell (RBC) units transfused. However, concerns about its safety have hindered its broader use.

Study Design and Methods  We evaluated the effect of TA on RBC transfusion and thromboembolic complications in total knee arthroplasty. We retrospectively studied 414 patients, 215 immediately before introducing TA treatment (control group) and after, in 199 patients without history of thromboembolic diseases (TA group). In a subgroup of patients, a lower extremities contrast venography was performed.

Results  Fifty‐four per cent of control group patients were transfused with RBC while only 17·6% of TA group patients received RBCs. In the TA that group, those transfused received less units (2·83 vs. 1·89), showed smaller mean calculated perioperative blood loss and haemoglobin values at discharge were higher compared to control group (10·1 vs. 9·3 g/dl). Thromboembolic complications were diagnosed in 2·8% of the patients in the control group and in 1·5% in the TA group. Asymptomatic distal deep venous thrombosis was found in 54 (14·8%) of TA group patients and 54 (30·1%) of control patients. TA administration reduced the expenditure for RBC transfusion plus the cost of TA from €148·94 to 33·87 per patient.

Conclusion  Routine administration of TA during total knee arthroplasty to patients without history of thromboembolic disease is associated with a 67% reduction in RBC transfusions and, in those transfused, with a reduction in the number of units administered. TA treatment was not associated with an increase in thromboembolic complications. Transfusion costs are significantly reduced.
Mountain pine beetle‐associated blue‐stain fungi are differentially adapted to boreal temperatures
Authors: Rice A. V. , Thormann M. N. , Langor D. W.
Published: March 2008

Mountain pine beetles (MPB) are the most serious pest of lodgepole pine in Canada and are likely to invade boreal jack pine forests. MPB vector three blue‐stain fungi, Grosmannia clavigera, Ophiostoma montium and Leptographium longiclavatum, which contribute to beetle success. Fungal survival at extreme boreal temperatures will contribute to their success in jack pine. Growth, sporulation and survival of the three fungi at −20 to 37°C were tested in vitro. Overwintering survival of G. clavigera and O. montium was assessed in vivo. All species grew at 5–30°C, with optimal growth at 20–25°C. Grosmannia clavigera and L. longiclavatum survived at −20°C, but O. montium died. Growth of G. clavigera and L. longiclavatum was inhibited at 30°C, but O. montium grew well. Grosmannia clavigera and O. montium overwintered in living pines. These results suggest that G. clavigera and L. longiclavatum were adapted to cold boreal winters but not hot summers, with the converse true for O. montium. Temperature tolerance varied among G. clavigera isolates. British Columbian and Californian isolates grew faster at 25°C than Albertan isolates. Isolates from Alberta and Idaho/Montana grew optimally at 20°C, while British Columbian and Californian isolates grew optimally at 25°C.
Reduction of albuminuria by angiotensin receptor blocker beyond blood pressure lowering: Evaluation in megsin/receptor for advanced glycation end products/inducible nitric oxide synthase triple transgenic diabetic nephropathy mouse model
Authors: OHTOMO SHUICHI , ITO MASAKI , IZUHARA YUKO , VAN YPERSELE DE STRIHOU CHARLES , MIYATA TOSHIO
Published: March 2008

Aim:  Antihypertensive agents inhibiting the renin‐angiotensin system (RAS), such as angiotensin II type 1 receptor blockers (ARB), are now part of the standard treatment of patients with diabetic nephropathy, regardless of the presence of systemic hypertension. Whether ARB achieve better renoprotection than other RAS‐independent antihypertensive drugs has been an issue of controversy. Several lines of large clinical studies provided better renoprotection of ARB. However, a recent meta‐analysis argued against additional benefits of ARB beyond blood pressure. We generated a novel mouse model of diabetic nephropathy; that is, megsin/receptor for advanced glycation end products/inducible nitric oxide synthase triple transgenic mice. This model is normotensive but progressively develops severe diabetic nephropathy that resembles those observed in humans.

Methods:  In the present study, we tested whether olmesartan (ARB) achieves better renoprotection than amlodipine (calcium channel blocker). Drug treatment was initiated at the age of 6 weeks and lasted for 12 weeks.

Results:  This model develops significant glomerular lesions and albuminuria even at the age of 5 weeks. Despite equal blood pressure lowering, only olmesartan suppressed the progression of albuminuria. Neither olmesartan nor amlodipine modified histological lesions.

Conclusion:  Proteinuria and its reduction are known to predict the progression of diabetic nephropathy. Our results support the additional benefit of ARB beyond blood pressure lowering.
R2: Identification of renal potential progenitor/stem cells that participate in the renal regeneration processes of kidney allograft fibrosis
Authors: BAO JI , TU ZHIDAN , SUN HUAIQIANG , LUO GUANGHENG , YANG LI , SONG JUN , QIN MINGXIA , SHI YUJUN , BU HONG , LI YOUPING
Published: March 2008

Aim:  Many strategies are explored to ameliorate kidney allograft tubular atrophy and interstitial fibrosis (TA/IF), but little progress has been achieved. The latest evidence suggested that CD133+ cell in kidney represent a potential multipotent adult resident stem cell population that may contribute to the renal injury repair. Here we investigate whether the CD133+ cells exist in transplanted renal and exert a growth and self‐repair procedure in TA/IF.

Methods:  Allografts from rat kidney transplant models were harvested at 4 weeks, 8 weeks and 12 weeks post transplantation. We performed immunohistochemistry to detect the CD133+ cells and immunofluorescence to detect the co‐expression of CD133 or Pax‐2 with Ki‐67. We furthermore analysed the E‐cadherin using serial sections.

Results:  CD133+ cells were seldom seen in control kidney, but distributed sporadically in the cortex parenchyma along with the deterioration of TA/IF. The number of CD133+ cell increased after 4 weeks and reached the peak at 8 weeks, then decreased at 12 weeks. From 8 weeks, some new tubules expressing E‐cadherin were constructed with CD133+ cells. Almost all the CD133+ cells were Ki‐67‐positive, but not all the Ki‐67+ cells expressed CD133. The rest Ki‐67+ cells almost expressed Pax‐2.

Conclusion:  Our study reveals that when majority of the tubules are damaged, a self‐repair mechanism is evoked by potential adult stem cells to compensate the renal function. Thus, potential adult resident stem cells offer a new avenue for autologous cell therapies in TA/IF.
Conserving the Richmond Birdwing Butterfly over two decades: Where to next?
Authors: Sands Don
Published: March 2008

Summary  The Richmond Birdwing Butterfly, restricted to subtropical areas of Australia, is threatened with extinction in the Queensland part of its range because of clearing and fragmenting rainforests containing its larval food vines. Habitat fragmentation and drought have exacerbated risks of inbreeding depression and a range of other threats exist, including invasions of the exotic Dutchmans Pipe Vine which is toxic to Richmond Birdwing larvae. This article outlines the Richmond Birdwing Butterfly project from its beginnings in the Double Helix Club project and recently the Richmond Birdwing Recovery Network. It provides details of the biology of the butterfy and its food vines, as well as discussing elements for consideration in a future recovery plan including (i) protecting the remaining breeding sites; and, for the shorter term (ii) continuing to propagate and plant food plants at appropriate localities that previously supported the butterfly.
Detecting unacceptable change in the ecological character of Ramsar wetlands
Authors: Davis Jenny , Brock Margaret
Published: March 2008

Summary  Managers of Ramsar‐listed wetlands throughout the world are committed to management that will promote the conservation and wise use of their wetland habitats. Part of the management process is a description of ‘ecological character’ as a benchmark against which a ‘change in ecological character’ can be assessed. Detecting unacceptable change is a difficult judgement, which depends upon an understanding of wetland ecosystem components, processes and services. This paper explores the development of conceptual models as a framework for describing the biophysical elements of ecological character of a wetland in a way that can be readily used for assessing changes. Ecosystem services are partially addressed but need further work to be more fully incorporated. We suggest development of models to identify components and key processes as well as drivers in the ecosystem. These models provide a description of a unique set of identifiers and a baseline against which unacceptable changes in biophysical character can be assessed. For an ecological character description to be useful for adaptive management, we suggest following the process, developed in a case study at Thomsons Lake, Western Australia, which: (i) provides a landscape context and identifies relevant spatial scales using a hierarchy of maps and aerial photographs; (ii) develops a conceptual ecological model with an accompanying synthesis of relevant biophysical data; and (iii) uses these as the basis for recognizing a unique set of wetland identifiers. The latter, together with critical processes, are the core biophysical elements of an ecological character description. Construction of a driver/stressor model facilitates the recognition of external drivers which create ecological stressors and lead to adverse ecological effects and loss of ecosystem services and benefits. It then follows that unacceptable changes in ecological character are those that result in a loss of identifiers, disrupt critical processes and reduce services or benefits.
Monitoring an invasive perennial at the landscape scale with remote sensing
Authors: Lawes Roger A. , Wallace Jeremy F.
Published: March 2008

Summary  Worldwide, invasive weeds threaten agricultural, natural and urban ecosystems. In Australia's agricultural and grazing regions, invasive species often establish across extensive areas where weed management is hampered by an inability to detect the location and timing of an outbreak. In these vast landscapes, an effective detection and monitoring system is required to delineate the extent of the invasion and identify spatial and temporal factors associated with weed establishment and thickening. In this study, we utilize a time series of remote sensing imagery to detect the spatial and temporal patterns of Prickly Acacia (Acacia nilotica) invasion in the Mitchell grass plains of North Queensland. We develop a spectral index from Landsat images which is applied to images from 1989 to 2004, in combination with a classification mask, to identify locations and monitor changes in Prickly Acacia density across 29 000 km2 of Mitchell grass plains. The approach identified spectral and temporal signatures consistent with Prickly Acacia infestation on 1.9% of this landscape. Field checking of results confirmed presence of the weed in previously unrecorded locations. The approach may be used to evaluate future spread, or outcomes of management strategies for Prickly Acacia in this landscape and could be employed to detect and monitor invasions in other extensive landscapes.
Retinopathy of prematurity: postmenstrual age at threshold in a transitional economy is similar to that in developed countries
Authors: Carden Susan Mary , Luu Lan Ngoc , Nguyen Tinh Xuan , Huynh Tess , Good William Vance
Published: March 2008

Abstract

Background:  To analyse the timing of threshold disease in infants requiring treatment for retinopathy of prematurity in a transitional economy.

Methods:  Design: Retrospective, observational, cohort study. Setting: National Hospital of Paediatrics, Hanoi, Vietnam. Study population: Premature infants in the Neonatal ward requiring laser treatment for threshold retinopathy of prematurity. Main outcome measures: Chronological age and postmenstrual age at treatment.

Results:  From January 2002 to November 2004, 42 infants from the National Hospital of Paediatrics required laser surgery for threshold retinopathy of prematurity. The mean ± standard deviation (SD) of birth weight was 1369 ± 184 g (range 1000–1700); the mean ± SD of gestation at birth was 30 ± 1.8 weeks (range 27–34); and the mean ± SD of postmenstrual age at which treatment occurred in these infants was 36.2 ± 2.5 weeks (range 31.4–42). A further 58 infants were transferred from other hospitals for laser surgery between January 2004 and October 2004. The mean ± SD of birth weight was 1325.5 ± 237.2 g (range 800–1900); the mean ± SD of gestation at birth was 30 ± 1.7 weeks (range 28–35); and the mean ± SD of postmenstrual age at which treatment was given in these infants was 36.3 ± 2.3 weeks (range 32.71–44.3).

Discussions:  Despite the relative maturity of the gestation of these infants compared with infants in developed countries who develop severe retinopathy of prematurity, the timing of treatment for threshold disease appears to be related to postmenstrual age.
Changes in corneal endothelial cell density and morphology after Ahmed glaucoma valve implantation during the first year of follow up
Authors: Kim Chang Sik , Yim Jin Ho , Lee Eun Kyoung , Lee Nam Ho
Published: March 2008

Abstract

Purpose:  To determine the effect of Ahmed glaucoma valve (AGV) implantation on corneal endothelial cells.

Methods:  Ahmed glaucoma valves were implanted in 30 eyes of 30 patients with refractory glaucoma. Corneal endothelial cell density and shape was prospectively evaluated in both the subject and fellow eyes of each patient. Corneal specular microscopy was performed on the superior, superotemporal, superonasal and central corneal areas before and at 1, 6 and 12 months after surgery.

Results:  A statistically significant decrease in average corneal endothelial cell density was observed 12 months postoperatively in the subject eyes compared with the baseline value (P = 0.001). No such changes were observed in the fellow eyes during follow‐up period. The mean percentage decrease in corneal endothelial cell density in subject eyes was 3.5% at 1 month, 7.6% at 6 months and 10.5% at 12 months after surgery. The superotemporal area, which was closest to the tube, showed the greatest decrease in endothelial cell density at 1 year after surgery, while the central cornea showed the least decrease. In terms of endothelial cell morphology, polymegathism and pleomorphism increased in the early postoperative periods, and then gradually approached the preoperative status by 6 months after surgery.

Conclusion:  Corneal endothelial cell density progressively decreased after AGV implantation. These findings indicate that particular care should be taken during intraoperative and postoperative management of AGV implantation patients in order to minimize damage to the endothelium.
Toxicology of the retina: advances in understanding the defence mechanisms and pathogenesis of drug‐ and light‐induced retinopathy
Authors: Siu Timothy L , Morley John W , Coroneo Minas T
Published: March 2008

Abstract

The neurosensory retina is a highly specialized sense organ that is subjected to constant exposure of systemic toxins, oxidative stress and focused light rays. Important advances have been made in recent decades in unravelling a myriad of defence mechanisms against such insults and consequently in improving the understanding of the principles underlying various drug‐ and light‐induced disease processes. To defend against circulating toxins, the retina possesses a specialized blood–retinal barrier (BRB) that tightly regulates the transport of substances across the functional boundaries of the retina at the retinal capillaries and the retinal pigmented epithelium. An endogenous cytochrome p450 system is strategically located within the retina to neutralize agents that can diffuse through the BRB. The biooxidation effect of light is prevented by a wide array of unique antioxidant mechanisms in the retina. Nonetheless, pathological processes may evolve when these different lines of defence are overwhelmed by various xenobiotics, environmental agents such as cigarette smoke and excessive light exposure, particularly of short wavelength high frequency blue light and ultraviolet light. Latest research using transgenic models has revealed novel apoptotic pathways implicated in acute phototoxicity, in particular blue light damage, and provides important clues for further understanding the risks of high‐frequency light exposure to human retinopathy. This review article summarizes the basic scientific principles of these different defence mechanisms and discuss the implications in pathophysiology and treatment.
Profiling of experience‐regulated proteins in the songbird auditory forebrain using quantitative proteomics
Authors: Pinaud Raphael , Osorio Cristina , Alzate Oscar , Jarvis Erich D.
Published: March 2008

Auditory and perceptual processing of songs are required for a number of behaviors in songbirds such as vocal learning, territorial defense, mate selection and individual recognition. These neural processes are accompanied by increased expression of a few transcription factors, particularly in the caudomedial nidopallium (NCM), an auditory forebrain area believed to play a key role in auditory learning and song discrimination. However, these molecular changes are presumably part of a larger, yet uncharacterized, protein regulatory network. In order to gain further insight into this network, we performed two‐dimensional differential in‐gel expression (2D‐DIGE) experiments, extensive protein quantification analyses, and tandem mass spectrometry in the NCM of adult songbirds hearing novel songs. A subset of proteins was selected for immunocytochemistry in NCM sections to confirm the 2D‐DIGE findings and to provide additional quantitative and anatomical information. Using these methodologies, we found that stimulation of freely behaving birds with conspecific songs did not significantly impact the NCM proteome 5 min after stimulus onset. However, following 1 and 3 h of stimulation, a significant number of proteins were consistently regulated in NCM. These proteins spanned a range of functional categories that included metabolic enzymes, cytoskeletal molecules, and proteins involved in neurotransmitter secretion and calcium binding. Our findings suggest that auditory processing of vocal communication signals in freely behaving songbirds triggers a cascade of protein regulatory events that are dynamically regulated through activity‐dependent changes in calcium levels.
Distribution and synthesis of extracellular matrix proteoglycans, hyaluronan, link proteins and tenascin‐R in the rat spinal cord
Authors: Galtrey Clare M. , Kwok Jessica C. F. , Carulli Daniela , Rhodes Kate E. , Fawcett James W.
Published: March 2008

Perineuronal nets (PNNs) are dense extracellular matrix (ECM) structures that form around many neuronal cell bodies and dendrites late in development. They contain several chondroitin sulphate proteoglycans (CSPGs), hyaluronan, link proteins and tenascin‐R. Their time of appearance correlates with the ending of the critical period for plasticity, and they have been implicated in this process. The distribution of PNNs in the spinal cord was examined using Wisteria floribunda agglutinin lectin and staining for chondroitin sulphate stubs after chondroitinase digestion. Double labelling with the neuronal marker, NeuN, showed that PNNs were present surrounding ∼ 30% of motoneurons in the ventral horn, 50% of large interneurons in the intermediate grey and 20% of neurons in the dorsal horn. These PNNs formed in the second week of postnatal development. Immunohistochemical staining demonstrated that the PNNs contain a mixture of CSPGs, hyaluronan, link proteins and tenascin‐R. Of the CSPGs, aggrecan was present in all PNNs while neurocan, versican and phosphacan/RPTPβ were present in some but not all PNNs. In situ hybridization showed that aggrecan and cartilage link protein (CRTL 1) and brain link protein‐2 (BRAL 2) are produced by neurons. PNN‐bearing neurons express hyaluronan synthase, and this enzyme and phosphacan/RPTPβ may attach PNNs to the cell surface. During postnatal development the expression of link protein and aggrecan mRNA is up‐regulated at the time of PNN formation, and these molecules may therefore trigger their formation.
Load‐related modulation of cutaneous reflexes in the tibialis anterior muscle during passive walking in humans
Authors: Nakajima Tsuyoshi , Kamibayashi Kiyotaka , Takahashi Makoto , Komiyama Tomoyoshi , Akai Masami , Nakazawa Kimitaka
Published: March 2008

Although cutaneous reflexes are known to be strongly modulated in a phase‐dependent manner during walking in both human and cat, it is not clear whether the movement‐related or the load‐sensitive afferent feedback plays a more important role in regulating this modulation. To address this issue in humans, we investigated modulation of the cutaneous reflex in the tibialis anterior muscles (TA) of 17 subjects during passive walking with a load (0%, 33%, 66% unloading of body weight) and without a load (100% unloading). These walking tasks were performed passively with a robotic gait trainer system. Cutaneous reflexes in TA, elicited by electrical stimulation to the distal tibial (Tib) and superficial peroneal (SP) nerves, were recorded during 10 different phases of the walking cycle, and the middle latency responses (MLR, 70–120 ms) were analysed. During loaded walking, the magnitudes of the MLR induced by Tib nerve stimulation were strongly increased during the late stance‐to‐early swing phase irrespective of the amount of load (phase modulation), a phenomenon that also occurred without background electromyogram in the TA. Predominant suppression of the MLR following SP nerve stimulation at the early stance phase changed to facilitation at the late stance. By contrast, the MLR following either Tib or SP nerve stimulation was not at all modulated by the stepping phase during both unloaded walking (100% unloading) and standing. These results suggest that phasic changes in the load‐related afferent information in concert with rhythmic lower limb movement play a key role in modulating cutaneous reflexes during walking.
Odor vapor pressure and quality modulate local field potential oscillatory patterns in the olfactory bulb of the anesthetized rat
Authors: Cenier Tristan , Amat Corine , Litaudon Philippe , Garcia Samuel , Lafaye de Micheaux Pierre , Liquet Benoît , Roux Stéphane , Buonviso Nathalie
Published: March 2008

A central question in chemical senses is the way that odorant molecules are represented in the brain. To date, many studies, when taken together, suggest that structural features of the molecules are represented through a spatio‐temporal pattern of activation in the olfactory bulb (OB), in both glomerular and mitral cell layers. Mitral/tufted cells interact with a large population of inhibitory interneurons resulting in a temporal patterning of bulbar local field potential (LFP) activity. We investigated the possibility that molecular features could determine the temporal pattern of LFP oscillatory activity in the OB. For this purpose, we recorded the LFPs in the OB of urethane‐anesthetized, freely breathing rats in response to series of aliphatic odorants varying subtly in carbon‐chain length or functional group. In concordance with our previous reports, we found that odors evoked oscillatory activity in the LFP signal in both the beta and gamma frequency bands. Analysis of LFP oscillations revealed that, although molecular features have almost no influence on the intrinsic characteristics of LFP oscillations, they influence the temporal patterning of bulbar oscillations. Alcohol family odors rarely evoke gamma oscillations, whereas ester family odors rather induce oscillatory patterns showing beta/gamma alternation. Moreover, for molecules with the same functional group, the probability of gamma occurrence is correlated to the vapor pressure of the odor. The significance of the relation between odorant features and oscillatory regimes along with their functional relevance are discussed.
Postoperative pain assessment in preverbal children and children with cognitive impairment
Authors: GHAI BABITA , MAKKAR JEETINDER KAUR , WIG JYOTSNA
Published: March 2008

Postoperative pain assessment and management in preverbal children and children with cognitive impairment poses major challenges to pediatric anesthesiologists. An accurate diagnosis of extent of pain is the keystone for the successful management of pain. This article reviews the neurobiology of pain at birth, long‐term consequences of early pain and different pediatric pain assessment tools used for postoperative assessment in infants, young children, and children with cognitive disabilities.
Ventilatory strategies for the extremely premature infant
Authors: GREENOUGH ANNE , PREMKUMAR MURALIDHAR , PATEL DEENA
Published: March 2008

Bronchopulmonary dysplasia (BPD), which has long‐term adverse outcomes, is common following extremely premature birth. BPD has a multifactorial etiology, including a high level or prolonged use of mechanical ventilation. Numerous research studies, therefore, have attempted to identify ventilatory techniques which reduce the likelihood of baro/volutrauma and hence BPD; these have been critically examined in this review, particularly with regard to their relevance to the extremely prematurely born infant. This has highlighted that few randomized studies of ventilatory strategies have concentrated exclusively on those high‐risk infants. Overall, in prematurely born infants, advantages have been suggested by the results of studies examining pressure support, proportional assist and volume‐targeted ventilation. In addition, High‐Frequency Oscillatory Ventilation (HFOV) may reduce the deterioration seen in lung function of prematurely born infants over the first year after birth. In conclusion, more randomized studies are required which concentrate exclusively on the extremely prematurely born population who are at highest risk of BPD. It is essential in such studies that long‐term follow‐up assessment is inbuilt so that the benefits/adverse effects can be appropriately identified.
Hemodynamic effects of dexmedetomidine sedation for CT imaging studies
Authors: MASON KEIRA P. , ZGLESZEWSKI STEVEN E. , PRESCILLA RANDY , FONTAINE PAULETTE J. , ZURAKOWSKI DAVID
Published: March 2008

Background:  Dexmedetomidine sedation for radiological imaging studies is a relatively recent application for this drug. Previous studies have demonstrated some haemodynamic effects of dexmedetomidine, however, the effects remain poorly described in children. The aim of this study was to better define the effect of age on heart rate (HR) and blood pressure changes in children sedated for CT imaging with dexmedetomidine.

Methods/materials:  At our institution dexmedetomidine is given for sedation for CT imaging as a bolus of 2 mcg·kg−1 over 10 min followed by an infusion of 1 mcg·kg−1·h−1 with a second bolus if required. Detailed quality assurance data sheets document patient demographics, sedation outcomes, adverse events, and hemodynamic data are recorded for each patient.

Results:  A total of 250 patients (range 0.1–10.6 years) received dexmedetomidine. anova revealed strong evidence for changes in HR and mean arterial blood pressure during bolus and infusion relative to presedation values (P < 0.001). These changes were apparent in each age group and similar between groups. During the first bolus and during infusion, 82% and 93% of patients respectively were within the age‐based normal range for HR. For mean arterial blood pressure, 70% of patients were within the normal range during first bolus and 78% during infusion.

Conclusion:  In the pediatric population studied, intravenous dexmedetomidine sedation was associated with modest fluctuations in HR and blood pressure. Hemodynamic changes were independent of age, required no pharmacologic interventions and did not result in any adverse events. By anticipating these possible hemodynamic effects and avoiding dexmedetomidine in those patients who may not tolerate such fluctuations in HR and blood pressure, dexmedetomidine is an appropriate sedative for children undergoing CT imaging.
Procedural pain and distress in young children as perceived by medical and nursing staff
Authors: BABL FRANZ E. , MANDRAWA CHRISTINE , O’SULLIVAN RONAN , CRELLIN DIANNE
Published: March 2008

Introduction:  Currently there is no comparison of pain and distress experienced by young children undergoing a range of procedures. This would be important when considering choices between alternative management approaches and to facilitate development of measures to reduce procedural pain and distress. We set out to determine staff perceptions of pain and distress across a range of common emergency procedures.

Methods:  Standardised survey of medical and nursing staff in the emergency department (ED) of a large urban tertiary children’s hospital. Staff perceptions of pain and distress of common ED procedures were measured using a 10 cm visual analogue scale. It included 15 common ED procedures, ranging from suprapubic aspiration (SPA) to measurement of oxygen saturation when performed in a child aged 12–18 months. It included four trauma related procedures. Respondents were stratified by their experience level with the procedures (50 procedures or less = less experienced, greater than 50 procedures = more experienced).

Results:  Ninety‐two of 150 medical and nursing staff in the ED (61%) responded including almost all full time staff. Twenty‐one percent of respondents were senior nurses, 17% senior physicians. The procedure considered the most painful was SPA [5.7 (4.0–7.2)cm]; as well as intramuscular injection (IMI) and lumbar puncture (LP). The procedures considered the most distressing were nasogastric tube (NGT) insertion [7.8(6.6–8.7)cm] as well as i.v. insertion and LP. All procedures were rated overall as more distressing than painful. Pain and distress were overall rated similarly regardless of staff experience level.

Conclusions:  SPA, IMI and LP are perceived by emergency staff as most painful and NGT insertion, i.v. insertion and LP are perceived as most distressing. These findings are important for clinicians when choosing alternative treatment strategies and for researchers in planning future investigations to reduce procedural pain and distress.
Prolonged sevoflurane inhalation therapy for status asthmaticus in an infant
Authors: WATANABE KAZUHIRO , MIZUTANI TARO , YAMASHITA SOICHIRO , TATEKAWA YUKIHIRO , JINBO TAKAHIRO , TANAKA MAKOTO
Published: March 2008

A 3‐month‐old boy with retractive breathing from his birth was scheduled for a rigid bronchoscopic examination. Anesthesia was induced and maintained with sevoflurane. The examination revealed a slight laryngomalacia which was not compatible with his severe symptom. During the procedure, no respiratory deterioration occurred. He was once extubated in the operating room, however, developed severe desaturation immediately. He was reintubated at the scene and returned to the ward being mechanically ventilated and sedated. The next day, his respiratory condition worsened gradually. Conventional drugs including theophylline, corticosteroid and beta adrenergic agonist did not improve his deleterious condition. He became bradycardic and was on the verge of circulatory collapse as his lungs were unable to ventilate. Then, we commenced inhalation of sevoflurane using a standard anesthesia machine, which relieved him from ventilatory crisis. Although there were some difficulties in using anesthesia machine in the ICU, we could successfully manage mechanical ventilation. After the beginning of sevoflurane inhalation, his condition improved gradually. Discontinuation of sevoflurane was difficult and it took 94 h to wean from sevoflurane inhalation. Despite long duration of inhalation, no adverse effects of sevoflurane were observed except transient mild increase in liver transaminase. There have been very few reports on application of sevoflurane inhalation for such a long period in infants with bronchospasm. Moreover, measured serum fluoride concentration (24.2 μmol·l−1) during inhalation was well below harmful level. Sevoflurane inhalation is worth attempting and safe to treat life‐threatening bronchospasm even in infants.
Experience with remifentanil–sevoflurane balanced anesthesia for abdominal surgery in neonates and children less than 2 years
Authors: MICHEL FABRICE , LANDO ANNIE , AUBRY CHRISTINE , ARNAUD SOPHIE , MERROT THIERRY , MARTIN CLAUDE
Published: March 2008

Background:  Few data report remifentanil use in the neonatal population. We described here our experience with remifentanil–sevoflurane balanced anesthesia in neonates and children less than 2 years who underwent general anesthesia for abdominal surgery.

Methods:  We retrospectively studied the pattern of remifentanil infusion associated with sevoflurane inhalation in preterm neonates (PTN; n = 18) (born before 37 weeks of gestation and <45 weeks of postmenstrual age), full‐term neonates (FTN; n = 21) (born after 37 weeks of gestation and less than 29 days old) and older children up to 2 years (CUT; n = 24). We recorded heart rate (HR), mean arterial pressure (MAP), mean remifentanil dose and sevoflurane concentration before incision and at 5, 10, 20, 30, 45, 60, 90, and 105 min after incision.

Results:  We observed that remifentanil doses used during surgery were lower in PTN than in both FTN and CUT and lower in FTN than in CUT. This was because of a progressive decrease in remifentanil dose during anesthesia in PTN and FTN. Conversely, remifentanil doses increased in CUT during anesthesia. Sevoflurane concentrations were higher in CUT group than in PTN and FTN groups. MAP and HR did not vary in the three groups during anesthesia.

Conclusions:  Remifentanil–sevoflurane anesthesia can be used for general anesthesia in neonates. We observed that anesthetists used lower doses of remifantanil and lower concentrations of sevoflurane in neonates compared with the older children.
Effects of head posture on the oral, pharyngeal and laryngeal axis alignment in infants and young children by magnetic resonance imaging
Authors: VIALET RENAUD , NAU ANDRÉ , CHAUMOÎTRE KATHIA , MARTIN CLAUDE
Published: March 2008

Background:  Objective anatomical studies supporting the different recommendations for laryngoscopy in infants and young children are scarce. The objective of this study was to measure by magnetic resonance imaging (MRI) the consequences of head extension on the oral, pharyngeal and laryngeal axes in infants and young children.

Methods:  Thirty patients (age: 33 ± 28 months; weight 14 ± 9 kg), under general inhalated anesthesia delivered via a laryngeal mask airway, were studied in two anatomic positions: head in the resting position and in simple extension. The following measurements were made on each scan: the face and the neck axes, the pharyngeal axis, the laryngeal axis, and the line of vision of glottis. The various angles between these axes were defined: δ angle between line of vision and laryngeal axis, and β angle between pharyngeal axis and laryngeal axis. From an anatomical point of view, laryngoscopy and passage of a naso‐tracheal tube would be facilitated if these angles are narrow.

Results:  Placing the patient from the resting position into extension led to a narrowing of the angle δ but a widening of the angle β.

Conclusions:  In infants and young children, under general anesthesia and with a laryngeal mask airway in place, just a slight head extension improves alignment of the line of vision of the glottis and the laryngeal axis (narrowing of angle δ) but worsened the alignment of the pharyngeal and laryngeal axes (widening of angle β).
A hotspot for cold crenarchaeota in the neuston of high mountain lakes
Authors: Auguet Jean‐Christophe , Casamayor Emilio O.
Published: March 2008

We have surveyed the first 1 m of 10 oligotrophic high mountain lakes in the Central Pyrenees (Spain) for both abundance and predominant phylotypes richness of the archaeaplankton assemblage, using CARD‐FISH and 16S rRNA gene sequencing respectively. Archaea inhabiting the air‐water surface microlayer (neuston) ranged between 3% and 37% of total 4,6‐diamidino‐2‐phenylindole (DAPI) counts and were mainly Crenarchaeota of a new freshwater cluster distantly related to the Marine Group 1.1a. Conversely, most of the Archaea from the underlying waters (the remaining first 1 m integrated) were mainly Euryarchaeota of three distantly related branches ranging between 0.4% and 27% of total DAPI counts. Therefore, a consistent qualitative and quantitative spatial segregation was observed for the two main archaeal phyla between neuston and underlying waters at a regional scale. We also observed a consistent pattern along the lakes surveyed between lake area, lake depth and water residence time, and the archaeal enrichment in the neuston: the larger the lake the higher the proportion of archaea in the neuston as compared with abundances from the underlying waters (n = 10 lakes; R2 > 0.80; P < 0.001, in all three cases). This is the first report identifying a widespread non‐thermophilic habitat where freshwater planktonic Crenarchaeota can be found naturally enriched. High mountain lakes offer great research opportunities to explore the ecology of one of the most enigmatic and far from being understood group of prokaryotes.
Vibrio cholerae non‐O1, non‐O139 strains isolated before 1992 from Varanasi, India are multiple drug resistant, contain intSXT, dfr18 and aadA5 genes
Authors: Mohapatra Harapriya , Mohapatra Saswat S. , Mantri Chinmay K. , Colwell Rita R. , Singh Durg V.
Published: March 2008

In this study, we report the presence of the SXT element and Class I integron in Vibrio cholerae non‐O1, non‐O139 strains isolated from Varanasi, India. Isolates were resistant to cotrimoxazole, trimethoprim and/or streptomycin, furazolidone and ampicillin. None contained plasmids. Polymerase chain reaction (PCR) and DNA sequencing revealed the presence of antibiotic resistance gene cassettes, aadA1, aadA2, aadA5 and dfrA15, in the Class I integron and SXT, an integrative conjugative element containing dfr18, sulII and strAB, in three and six of the isolates respectively. Conjugation experiments, followed by PCR analysis of transconjugants, provided evidence for the transferable nature of intSXT and associated antibiotic resistance gene cassettes. This is the first report of the occurrence of SXT ICE, dfr18, sulII, strAB and aadA5 genes in environmental V. cholerae non‐O1, non‐O139 strains from Varanasi, India, that had been isolated before 1992.
Shell disease in crustaceans – just chitin recycling gone wrong?
Authors: Vogan Claire L. , Powell Adam , Rowley Andrew F.
Published: March 2008

The exoskeletons of aquatic crustaceans and other arthropods contain chitin, a biopolymer of β‐(1,4)‐linked N‐acetylglucosamine together with associated proteins. Despite the vast amounts of chitin within such animals little is found in sediments and open water because microorganisms rapidly degrade this following its loss after moulting or upon the animals' death. Shell disease syndrome is a worldwide disease condition that affects a wide range of crustaceans. It comes about as a result of bacterial degradation of the exoskeleton leading to unsightly lesions and even death if the underlying tissues become infected. There are at least two potential forms of the disease; one that appears to centre around chitin degradation and an additional form termed ‘epizootic’ shell disease, in which chitin degradation is of less significance. This account reviews our current understanding of the causative agents of this syndrome, assesses the potential economic consequences of the disease, and critically examines whether it is associated with anthropogenic disturbances including pollution. Overall, despite extensive studies during the last few decades, the potential links between faecal, heavy metal and insecticide pollution and shell disease are still unclear.
Prokaryotic diversity of arctic ice shelf microbial mats
Authors: Bottos Eric M. , Vincent Warwick F. , Greer Charles W. , Whyte Lyle G.
Published: March 2008

The prokaryotic diversity and respiratory activity of microbial mat communities on the Markham Ice Shelf and Ward Hunt Ice Shelf in the Canadian high Arctic were analysed. All heterotrophic isolates and > 95% of bacterial 16S rRNA gene clone library sequences from both ice shelves grouped within the phyla Bacteroidetes, Proteobacteria and Actinobacteria. Clone library analyses showed that the bacterial communities were diverse and varied significantly between the two ice shelves, with the Markham library having a higher estimated diversity (Chao1 = 243; 105 operational taxonomic units observed in 189 clones) than the Ward Hunt library (Chao1 = 106; 52 operational taxonomic units observed in 128 clones). Archaeal 16S rRNA gene clone libraries from both ice shelves were dominated by a single Euryarchaeota sequence, which appears to represent a novel phylotype. Analyses of community activity by radiorespiration assays detected metabolism in mat samples from both ice shelves at temperatures as low as −10°C. These findings provide the first insight into the prokaryotic biodiversity of Arctic ice shelf communities and underscore the importance of these cryo‐ecosystems as a rich source of microbiota that are adapted to extreme cold.
Community structures of actively growing bacteria shift along a north‐south transect in the western North Pacific
Authors: Taniguchi Akito , Hamasaki Koji
Published: March 2008

Bacterial community structures and their activities in the ocean are tightly coupled with organic matter fluxes and thus control ocean biogeochemical cycles. Bromodeoxyuridine (BrdU), halogenated nucleoside and thymidine analogue, has been recently used to monitor actively growing bacteria (AGB) in natural environments. We labelled DNA of proliferating cells in seawater bacterial assemblages with BrdU and determined community structures of the bacteria that were possible key species in mediating biochemical reactions in the ocean. Surface seawater samples were collected along a north‐south transect in the North Pacific in October 2003 and subjected to BrdU magnetic beads immunocapture and PCR‐DGGE (BUMP‐DGGE) analysis. Change of BrdU‐incorporated community structures reflected the change of water masses along a north‐south transect from subarctic to subtropical gyres in the North Pacific. We identified 25 bands referred to AGB as BrdU‐incorporated phylotypes, belonging to Alphaproteobacteria (5 bands), Betaproteobacteria (1 band), Gammaproteobacteria (4 bands), Cytophaga‐Flavobacterium‐Bacteroides (CFB) group bacteria (5 bands), Gram‐positive bacteria (6 bands), and Cyanobacteria (4 bands). BrdU‐incorporated phylotypes belonging to Vibrionales, Alteromonadales and Gram‐positive bacteria appeared only at sampling stations in a subtropical gyre, while those belonging to Roseobacter‐related bacteria and CFB group bacteria appeared at the stations in both subarctic and subtropical gyres. Our result revealed phylogenetic affiliation of AGB and their dynamic change along with north‐south environmental gradients in open oceans. Different species of AGB utilize different amount and kinds of substrates, which can affect the change of organic matter fluxes along transect.
The odd behaviour of carbonic anhydrase in the terrestrial cyanobacterium Nostoc flagelliforme during hydration–dehydration cycles
Authors: Ye Changpeng , Gao Kunshan , Giordano Mario
Published: March 2008

The terrestrial cyanobacterium Nostoc flagelliforme, inhabiting arid areas, withstands prolonged periods of dehydration. How dehydration and occasional wetting affect inorganic C acquisition in this organism is not well known. As inorganic C acquisition in cyanobacteria often involves carbonic anhydrases (CA), we studied the effect of cycles of hydration and dehydration on the extracellular and intracellular CA activities, at the pH values presumably associated with dew or rain wetting. The external CA of N. flagelliforme (or of the microorganismal consortium of which N. flagelliforme is the main component) is activated by hydration, especially at low pH, and it may facilitate inorganic C acquisition when N. flagelliforme colonies are wetted by dew. Internal CA is present in dry colonies and is rapidly inactivated upon rehydration, therefore an anaplerotic role for this enzyme is proposed.