bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma ghrelin levels of gastrectomized and vagotomized patients are not affected by glucose administration
Authors: Pekic S. , Pesko P. , Djurovic M. , Miljic D. , Doknic M. , Glodic J. , Dieguez C. , Casanueva F. F. , Popovic V. 
Published: April 2006

SummaryBackground  Ghrelin is a brain–gut peptide with GH‐releasing and appetite‐inducing activities, secreted mainly by the stomach. Circulating ghrelin concentrations fall rapidly after nutrient ingestion as well as after oral and intravenous glucose challenge. A number of gut hormones including ghrelin require an intact vagal system, which has been hypothesized to have a major role in initiating the postprandial fall in ghrelin levels.Aim  We aimed to investigate the effect of oral glucose challenge on ghrelin secretion in gastrectomized (GASTRX) and vagotomized patients.Design  Interventional study.Patients  Six GASTRX–vagotomized patients and 11 healthy sex‐ and body mass index (BMI)‐matched subjects.Methods  An oral glucose tolerance test (OGTT) was performed in all subjects. At baseline, circulating plasma total ghrelin, serum glucose, insulin and GH levels were measured. Serum glucose, insulin, GH and plasma ghrelin levels were determined every 30 min for 2 h.Results  Plasma ghrelin levels at baseline were reduced by 55% in GASTRX–vagotomized patients compared to the control group (P < 0·01). In control subjects, plasma ghrelin levels decreased significantly during the OGTT whereas in GASTRX–vagotomized patients no reduction was registered (26·4 ± 2·8%vs. 5·5 ± 3·4%). The OGTT revealed a significantly greater increase in circulating glucose levels and serum insulin levels while GH response was not different in GASTRX–vagotomized patients compared to control subjects.Conclusions  Our data show that circulating ghrelin levels in GASTRX and vagotomized patients were not suppressed after oral glucose administration, unlike control subjects, suggesting that this effect could be due, at least in part, to the lack of contribution of the vagal nervous system to the regulation of ghrelin.
Mycorrhizal mediation of plant N acquisition and residue decomposition: Impact of mineral N inputs
Authors: TU CONG , BOOKER FITZGERALD L. , WATSON DOROTHY M. , CHEN XIN , RUFTY THOMAS W. , SHI WEI , HU SHUIJIN 
Published: April 2006

AbstractMycorrhizas are ubiquitous plant–fungus mutualists in terrestrial ecosystems and play important roles in plant resource capture and nutrient cycling. Sporadic evidence suggests that anthropogenic nitrogen (N) input may impact the development and the functioning of arbuscular mycorrhizal (AM) fungi, potentially altering host plant growth and soil carbon (C) dynamics. In this study, we examined how mineral N inputs affected mycorrhizal mediation of plant N acquisition and residue decomposition in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that either prevented or allowed AM fungal hyphae but not plant roots to grow into the TEST compartments. Wild oat (Avena fatua L.) was planted in the HOST compartments that had been inoculated with either a single species of AM fungus, Glomus etunicatum, or a mixture of AM fungi including G. etunicatum. Mycorrhizal contributions to plant N acquisition and residue decomposition were directly assessed by introducing a mineral 15N tracer and 13C‐rich residues of a C4 plant to the TEST compartments. Results from 15N tracer measurements showed that AM fungal hyphae directly transported N from the TEST soil to the host plant. Compared with the control with no penetration of AM fungal hyphae, AM hyphal penetration led to a 125% increase in biomass 15N of host plants and a 20% reduction in extractable inorganic N in the TEST soil. Mineral N inputs to the HOST compartments (equivalent to 5.0 g N m−2 yr−1) increased oat biomass and total root length colonized by mycorrhizal fungi by 189% and 285%, respectively, as compared with the no‐N control. Mineral N inputs to the HOST plants also reduced extractable inorganic N and particulate residue C proportion by 58% and 12%, respectively, in the corresponding TEST soils as compared to the no‐N control, by stimulating AM fungal growth and activities. The species mixture of mycorrhizal fungi was more effective in facilitating N transport and residue decomposition than the single AM species. These findings indicate that low‐level mineral N inputs may significantly enhance nutrient cycling and plant resource capture in terrestrial ecosystems via stimulation of root growth, mycorrhizal functioning, and residue decomposition. The long‐term effects of these observed alterations on soil C dynamics remain to be investigated.
Potential impacts of climate change on nitrogen transformations and greenhouse gas fluxes in forests: a soil transfer study
Authors: HART STEPHEN C. 
Published: April 2006

AbstractRelatively little research has been conducted on how climate change may affect the structure and function of arid to semiarid ecosystems of the American Southwest. Along the slopes of the San Francisco Peaks of Arizona, USA, I transferred intact soil cores from a spruce‐fir to a ponderosa pine forest 730 m lower in elevation to assess the potential impacts of climate change on soil N cycling and trace gas fluxes. The low‐elevation site has a mean annual soil temperature about 2.5°C higher than the high‐elevation site. Net rates of N transformations and trace gas fluxes were measured in high‐elevation soil cores incubatedin situand soil cores transferred to the low‐elevation site. Over a 13‐month period, volumetric soil water content was similar in transferred soil cores relative to soil cores incubatedin situ. Net N mineralization and nitrification increased over 80% in transferred soil cores compared within situsoil cores. Soil transfer significantly increased net CO2efflux (120%) and net CH4consumption (90%) relative to fluxes of these gases from soil cores incubatedin situ. Soil net N2O fluxes were relatively low and were not generally altered by soil transfer. Although the soil microbial biomass as a whole decreased in transferred soil cores compared within situsoil cores after the incubation period, active bacterial biomass increased. Transferring soil cores from the low‐elevation to the high‐elevation site (i.e. simulated global cooling) commonly, but not consistently, resulted in the opposite effects on soil pools and processes. In general, soil containment (root trenching) did not significantly affect soil measurements. My results suggest that small increases in mean annual temperature can have large impacts on soil N cycling, soil–atmosphere trace gas exchanges, and soil microbial communities even in ecosystems where water availability is a major limiting resource.
Absence of post‐Miocene Red Sea land bridges: biogeographic implications
Authors: Fernandes Carlos A. , Rohling Eelco J. , Siddall Mark 
Published: April 2006

AbstractIn a large number of studies concerned with species movements between Africa and Eurasia, including the migrations of hominids out of Africa, a frequently‐cited dispersal route is across a hypothetical land bridge in the southern Red Sea, which is suggested to have emerged during glacial sea‐level lowstands. This paper, however, unequivocally demonstrates that palaeoceanographic and palaeoecological data are incompatible with the existence of Red Sea land bridges since the Miocene. The case is made by presenting the first quantitative history of water depth above the Red Sea sill for the last 470,000 years, a time period that includes the four most recent glacial–interglacial cycles, and by discussing the predictable consequences of any land bridge formation on the Red Sea sedimentary and microfossil records. The absence of post‐Miocene Red Sea land bridges has extensive implications for biogeographic models in the Afro‐Arabian region. Genetic, morphometric and palaeontological patterns reported in the literature cannot be related to dispersals over a land bridge, or in the case of marine organisms, separation of the Red Sea from the Indian Ocean by a land bridge. If such patterns in terrestrial species are only congruent with a southern Red Sea dispersal route, then they need to be considered in terms of sweepstake rafting, anthropogenic introduction, or in the particular case of the Out‐of‐Africa migration by modern humans, seafaring. The constraints imposed by our palaeoenvironmental record on biogeographic reconstructions within and around the Red Sea will hopefully encourage both the review of previous works and the preference for multidisciplinary approaches in future studies.
Patients’ experiences of living with oesophageal cancer
Authors: Andreassen Sissel , Randers Ingrid , Näslund Erik , Stockeld Dag , Mattiasson Anne‐Cathrine 
Published: April 2006

Aims.  The aim of this study is to describe patients’ experiences of living with oesophageal cancer and how they seek information.Background.  Oesophageal cancer is a devastating disease with poor prognosis. Nursing care for individuals with oesophageal cancer requires increased knowledge of how they experience illness and how it affects them.Method.  Data were collected by semi‐structured, qualitative interviews with 13 participants. Content analysis was used to analyse data.Results.  Four themes were identified: (i) Experiences of becoming a patient diagnosed with oesophageal cancer is distinguished by the participants’ experiences of vague symptoms, of receiving the diagnosis and of existential concerns evoked by the illness. (ii) Experiences of undergoing investigations and treatment consist of the participants’ experiences of extreme tiredness in relation to investigations and treatment. (iii) Experiences of intrusions in daily life is conceptualized by the participants’ experiences of how the illness influenced their daily life. (iv) Managing a life‐threatening illness consists of a variety of strategies, which the participants employed to manage their life‐threatening illness.Conclusions.  The participants were unprepared of receiving a diagnosis of oesophageal cancer. Dysphagia, fatigue and uncertainty influenced the participants’ everyday life. To manage the illness one of their strategies was seeking for information. The physicians were considered the main source of information, but family as well as friends with medical knowledge were also acknowledged as valuable sources.Relevance to clinical practice.  Understanding patients’ experiences of living with oesophageal cancer is important to improve nursing care. When caring for these patients, focus ought to be on the whole family. In nursing care, it is important to be aware of the effects of dysphagia and fatigue. Health‐care professionals ought to organize meetings with fellow patients and recommend literature and websites that provide patients with high quality information.
Genetic differentiation of the marbled white butterfly, Melanargia galathea, accounts for glacial distribution patterns and postglacial range expansion in southeastern Europe
Authors: SCHMITT THOMAS , HABEL JAN CHRISTIAN , ZIMMERMANN MARCO , MÜLLER PAUL 
Published: April 2006

AbstractIsolation of Mediterranean species in the southern European peninsulas during the cold glacial phases often resulted in differentiation of several genetic lineages confined to the respective peninsulas. However, whilst there is good genetic evidence for multiple refugia in Iberia, there are only limited data available for the Balkans. Therefore, we wish to examine the hypothesis of a strong genetic structuring within southeastern Europe for the existence of multiple Balkan differentiation centres and/or several leading edges. As a model we use the marbled white butterfly, Melanargia galathea. We studied 18 allozyme loci of 564 individuals from 16 populations distributed over a large part of southeastern Europe. The single populations showed moderately high genetic diversity and no northward decline of genetic diversity was detected. The overall genetic differentiation between populations was considerable (FST 7.0%). Cluster analysis discriminated three genetic groups: (i) a western flank in the former Yugoslavia, parts of eastern Austria and Hungary; (ii) an eastern flank with populations from Bulgaria and Romania (south of the southern Carpathians and eastern Carpathians); and (iii) the eastern Carpathian Basin. Hierarchical variance analysis distributed 53% of the variance among populations between these three groups. One sample from the Greek–Bulgarian border clustered within the eastern flank, but showed some tendency towards the eastern Carpathian Basin populations. Two populations from Carinthia clustered together with the eastern Carpathian Basin ones and a population from Styria showed an intermediate genetic composition between the three groups. Most probably, the eastern and the western flank groups are due to postglacial range expansion from the northeastern and the northwestern edges of the glacial differentiation centre (so‐called leading edges). The eastern Carpathian Basin group may have resulted from postglacial expansion from northern Greece through valley systems of the central Balkan peninsula, maybe even expanding westwards north of the Balkan mountains reaching some parts of eastern Austria (e.g. Carinthia). Therefore, the Balkanic refugium of M. galathea may or may not have been continuous along the coastal areas of the Mediterranean, but must have been strongly genetically structured.
Genome‐wide analysis of high‐altitude maize and gene knockdown stocks implicates chromatin remodeling proteins in response to UV‐B
Authors: Casati Paula , Stapleton Ann E. , Blum James E. , Walbot Virginia 
Published: April 2006

SummaryA comparative analysis, by expression profiling of maize, was performed to identify novel components in the mechanisms of maize responses to UV‐B. Five high‐altitude landraces grown from 2000 to 3400 m naturally receive higher UV‐B fluence than plants at lower altitudes and similar latitudes. These high‐altitude landraces were compared directly with a low‐altitude line and with literature reports for other temperate maize lines. A microarray analysis demonstrated that among the UV‐B responsive transcripts, several types of gene implicated in chromatin remodeling are differentially expressed before and after UV‐B treatment in high‐altitude lines. RNAi transgenic plants with lower expression of four such chromatin‐associated genes exhibited hypersensitivity to UV‐B by measurements of leaf arching, increased leaf chlorosis and necrosis, and altered UV‐B regulation of selected genes. These results collectively suggest that genes involved in chromatin remodeling are crucial for UV‐B acclimation and that some high‐altitude lines exhibit adaptations to this challenge.
Replicated population divergence caused by localized coevolution? A test of three hypotheses in the red crossbill-lodgepole pine system
Authors: Edelaar P. , Benkman C. W. 
Published: April 2006

Abstract
Several lines of evidence support the hypothesis that local populations of red crossbills (Loxia curvirostra complex) enter into a predator-prey arms race with lodgepole pine (Pinus contorta latifolia) in the absence of competing pine squirrels (Tamiasciurus hudsonicus). Nevertheless, the alternative hypotheses that neutral evolution or factors other than squirrels have caused crossbill population differentiation have not been thoroughly tested. We compared crossbill and pine cone morphology between island populations where squirrels are absent or present, and mainland sites where squirrels are present, in order to distinguish among these hypotheses. All comparisons supported an effect of squirrel absence, not island status, on crossbill and cone morphology. Hence our results provide further evidence that strong localized coevolutionary interactions in a geographic mosaic have driven adaptive population differentiation. In addition, vocal differentiation of crossbills was related to the absence of squirrels, but not to island status. As morphological and vocal differentiation is correlated with reproductive isolation in crossbills, the geographic mosaic of coevolution also seems to promote ecological speciation.
Psychological effects of repeated general anesthesia in children
Authors: KAYAALP LEVENT , BOZKURT PERVIN , ODABASI GURKAN , DOGANGUN BURAK , CAVUSOGLU PERVIN , BOLAT NURULLAH , BAKAN MEFKUR 
Published: April 2006

AbstractBackground:  Although methods for reducing preoperative anxiety have been a major interest of pediatric anesthesiologists, there are no reports of the effects of repeated anesthesia on psychological development of children.Methods:  To determine the overall effect of multiple anesthetics on the psychology of children, we undertook to compare the children undergoing repeated anesthesia (Group S) for the treatment of corrosive esophagitis with a control group (Group C) with chronic renal disease and frequent hospital admissions. Psychological tests and diagnosis of children Group S (n = 23) were compared prospectively with Group C (n = 20). All children had been appropriately treated over the previous 5 years and 50% of patients in Group C had general anesthesia once and those in Group S underwent at least 5 GAs. Parents completed a child behavior checklist (CBCL) and Marital Conflict Questionnaire; the children were evaluated by a child psychiatrist using DSM‐IV criteria and completed the Child Depression Inventory (CDI).Results:  The children in Group S underwent a total of 251 (11 ± 7) GAs over 4–60 months. The incidence of psychopathology was nine and 10 children in groups S and C, respectively. The CBCL and CDI scores were parallel with a psychiatric diagnosis. Marital conflict scores were higher in Group S.Conclusions:  Both chronic disease states affect psychology of children. Repeated anesthesia in addition to chronic disease does not seem to disturb the child's psychological health further when tentative and precautious approach modalities are undertaken.
Continuous infraclavicular brachial plexus block in a child
Authors: FISHER PHOEBE , WILSON SAMUEL E. , BROWN MELINDA , DITUNNO THERESA 
Published: April 2006

SummaryContinuous regional anesthesia for both intra‐ and postoperative use in adults is becoming more common. As with many new anesthesia techniques, however, there is often a lag time before the same techniques are utilized in children. Our patient was a 10‐year‐old child requiring reoperation on her fifth digit with planned 48‐h admission for range of motion exercises. We wanted to have a continuous regional blockade to control the patient's pain during the postoperative manipulations of the digit. A search of the literature from the last 10 years did not show any reports of the placements of a continuous brachial plexus block in children. In this case report, we present the successful placement and use of a continuous infraclavicular catheter in a child undergoing upper extremity surgery.
The impact of long chain n‐3 polyunsaturated fatty acid supplementation on inflammation, insulin sensitivity and CVD risk in a group of overweight women with an inflammatory phenotype
Authors: Browning L. M. , Krebs J. D. , Moore C. S. , Mishra G. D. , O’Connell M. A. , Jebb S. A. 
Published: April 2006

Background:  Inflammation is strongly related to obesity and the risk of cardiovascular disease (CVD). The metabolic benefits of long chain (LC) n‐3 polyunsaturated fatty acid (PUFA) may be attributable to its anti‐inflammatory properties.Objective:  To investigate whether an individual’s habitual inflammatory status influences the impact of a LC n‐3 PUFA intervention on CVD risk.Design:  The study was a randomized crossover design. Subjects received LC n‐3 PUFA capsules or a placebo for 12 weeks, with 4‐week washout between phases. Thirty women, in the top and bottom tertiles of baseline sialic acid concentration, formed raised inflammatory status (top, n = 12) and reference (bottom, n = 18) groups. Baseline data were analysed using one‐way anova, differences between treatment phases were calculated at each timepoint and analysed using a random effects model.Results:  At baseline, the raised inflammatory status group had significantly higher body mass index and area under the curve (AUC) insulin than the reference group. With LC n‐3 PUFA supplementation, both groups showed significantly higher plasma eicosapentaenoic acid and docosahexaenoic acid at 4 and 12 weeks (p < 0.001), and lower triacylglycerols (4 weeks p < 0.01 and 12 weeks p < 0.05). The difference in AUC insulin between the two treatment phases at 12 weeks was significantly greater in the raised inflammatory status group compared to the reference group (p < 0.05). Inflammatory markers were significantly lower after 12 weeks LC n‐3 PUFA supplementation compared to baseline (C‐reactive protein p < 0.05 and interleukin‐6 p < 0.01), but there was no significant group effect.Conclusions:  Habitual inflammatory status influences the impact of LC n‐3 PUFA supplementation, but it is not clear whether the effect of LC n‐3 PUFA on AUC insulin is mediated through inflammatory mechanisms.
Effects of S 15511, a therapeutic metabolite of the insulin‐sensitizing agent S 15261, in the Zucker Diabetic Fatty rat
Authors: Pickavance L. C. , Wilding J. P. H. 
Published: April 2006

Aim:  S 15261 is a novel oral antihyperglycaemic drug with both insulin secretagogue and insulin‐sensitizing effects. The study was designed to determine the biological activity of its two major metabolites, S 15511 and Y 415, and whether or not they have an additive effect.Methods:  Zucker Diabetic Fatty rats were treated for 28 days with S 15511 (10 mg/kg), Y 415 (10 mg/kg), or a combination at the same doses for a period of 4 weeks starting at 6–7 weeks of age. An additional group was pair‐fed to the level of S 15511‐treated animals to determine if possible effects were due to reduced food intake.Results:  S 15511 alone and combined with Y 415 reduced energy intake and weight gain (−13% vs. controls; both p < 0.01). Baseline fasting plasma glucose levels were maintained by S 15511, S 15511 + Y 415 and pair‐feeding (p < 0.01) for the entire treatment period (p < 0.01). Baseline insulin was maintained by pair‐feeding only, whereas all other treated groups became hyperinsulinaemic (+110–276%; p < 0.05). Deterioration in insulin sensitivity [homeostasis model assessment (HOMA)‐IR: + 239%; p < 0.01] was attenuated by S 15511, S 15511 + Y 415 and pair‐feeding (p < 0.01) and was compensated for by improved insulin secretion (HOMA‐β; p < 0.01). Oral glucose tolerance tests, performed on days 0, 14 and 28, showed that all groups had an impaired insulin response, but by day 28, S 15511, S 15511 + Y 415 and pair‐feeding had improved glucose disposal compared to the progressive deterioration in untreated controls (−44% to −48% vs. controls; p < 0.01), associated with progression to frank diabetes in these animals.Conclusion:  Treatment with these agents in a genetic model of type 2 diabetes reveals that they all have a transient effect compared to the progressive worsening of vehicle‐treated controls. The improvements in glucose metabolism observed with S 15511 are significant, however, suggesting it has more therapeutic activity than the Y 415 metabolite of S 15261. It is associated with less frequent progression to diabetes; i.e. Y 415 exerts a non‐significant effect alone and no significant additive effect when combined with S 15511. The mechanism of action of S 15511 may be via increased insulin sensitivity and β‐cell response preservation up to day 21. Thus, previously reported insulin secretagogue effects are likely to be attributable to the parent compound.