bluuebunny/crossref_metadata_2025 huggingface dataset:
Significance of cold‐season respiration and photosynthesis in a subarctic heath ecosystem in Northern Sweden
Authors: LARSEN KLAUS STEENBERG , IBROM ANDREAS , JONASSON SVEN , MICHELSEN ANDERS , BEIER CLAUS
Published: June 2007

While substantial cold‐season respiration has been documented in most arctic and alpine ecosystems in recent years, the significance of cold‐season photosynthesis in these biomes is still believed to be small. In a mesic, subartic heath during both the cold and warm season, we measured in situ ecosystem respiration and photosynthesis with a chamber technique at ambient conditions and at artificially increased frequency of freeze–thaw (FT) cycles during fall and spring. We fitted the measured ecosystem exchange rates to respiration and photosynthesis models with R2‐values ranging from 0.81 to 0.85. As expected, estimated cold‐season (October, November, April and May) respiration was significant and accounted for at least 22% of the annual respiratory CO2 flux. More surprisingly, estimated photosynthesis during this period accounted for up to 19% of the annual gross CO2 uptake, suggesting that cold‐season photosynthesis partly balanced the cold‐season respiratory carbon losses and can be significant for the annual cycle of carbon. Still, during the full year the ecosystem was a significant net source of 120 ± 12 g C m−2 to the atmosphere. Neither respiration nor photosynthetic rates were much affected by the extra FT cycles, although the mean rate of net ecosystem loss decreased slightly, but significantly, in May. The results suggest only a small response of net carbon fluxes to increased frequency of FT cycles in this ecosystem.
Ecosystem carbon accretion 10 years after afforestation of depleted subhumid grassland planted with three densities of Pinus nigra
Authors: DAVIS MURRAY , NORDMEYER ALAN , HENLEY DAVID , WATT MICHAEL
Published: June 2007

Biomass and soil carbon (C) and nitrogen (N) were measured in a replicated trial after afforestation of a New Zealand upland subhumid low‐productivity grassland with four tree stockings, including an unplanted control, of Pinus nigra. Total biomass accumulation of P. nigra in the cool, dry and N‐limited environment was low, ranging from 10 to 20 Mg ha−1 dry weight at age 10. Carbon and N accumulation in above‐ and belowground tree biomass ranged between 5–10 and 0.03–0.07 Mg ha−1, respectively. Soil C, N and bulk density were measured 5 and 10 years after the trees were planted. Soil samples taken at year 5 from between tree rows spaced 5 m apart were considered to be representative of grassland not affected by afforestation. Co‐variance analysis showed that, at year 10, soil C and N concentrations, and soil bulk density and C and N mass were not significantly affected by afforestation. The results are at variance with paired site studies in more humid environments that show soil C declines following afforestation, but confirm other studies and model predictions that show soil C decline in the early stages after afforestation in low‐productivity environments is limited. Afforestation did not affect root biomass of herbaceous species and this may have contributed to the lack of effect on soil C. Although afforestation by itself did not significantly affect soil C and N, over the measurement period soil C concentrations increased, while soil N declined by 450 kg ha−1. The decline in soil N was confined to lower soil layers and could not be accounted for by uptake in vegetation. The observed decline in soil N is consistent with results of other work in grazed, depleted grassland in the region that indicates losses of soil N occur that cannot be accounted for by pathways directly associated with grazing.
Effects of three years of soil warming and shading on the rate of soil respiration: substrate availability and not thermal acclimation mediates observed response
Authors: HARTLEY IAIN P. , HEINEMEYER ANDREAS , INESON PHIL
Published: June 2007

In a number of recent field studies, the positive response of soil respiration to warming has been shown to decline over time. The two main differing hypotheses proposed to explain these results are: (1) soil microbial respiration acclimates to the increased temperature, and (2) substrate availability within the soil decreases with warming so reducing the rate of soil respiration. To investigate the relative merits of these two hypotheses, soil samples (both intact cores and sieved samples) from a 3‐year grassland soil‐warming and shading experiment were incubated for 4 weeks at three different temperatures under constant laboratory conditions. We tested the hypothesis that sieving the soils would reduce differences in substrate availability between warmed and control plot samples and would therefore result in similar respiration rates if microbial activity had not acclimated to soil warming. In addition, to further test the effect of substrate availability, we compared the respiration rates of soils taken from shaded and unshaded plots. Both soil warming and shading significantly reduced respiration rates in the intact cores, especially under higher incubation temperatures. However, sieving the soil greatly reduced these differences suggesting that substrate availability, and not microbial acclimation to the higher temperatures, played the dominant role in determining the response of heterotrophic soil respiration to warming. The effect of shading appeared to be mediated by reduced plant productivity affecting substrate availability within the soil and hence microbial activity. Given the lack of evidence for thermal acclimation of microbial respiration, there remains the potential for prolonged carbon losses from soils in response to warming.
Responses of estuarine intertidal microphytobenthic algal assemblages to enhanced ultraviolet B radiation
Authors: WARING JEN , BAKER NEIL R. , UNDERWOOD GRAHAM J. C.
Published: June 2007

As a result of ozone depletion, ground doses of ultraviolet B (UVB) radiation in the mid latitudes of the Northern Hemisphere have increased since the 1980s, and current predictions indicate no possible alleviation until at least post 2020. Mudflats and sandflats are important coastal‐zone habitats, and support extensive biofilms of benthic microalgae (microphytobenthos). In intertidal situations, these assemblages are exposed to high levels of UVB radiation during periods of tidal exposure. Exposure of intertidal biofilms dominated by epipelic (mud‐inhabiting) diatoms to 0, 0.18 or 0.35 W m−2 UVB radiation for between 4 and 10 days resulted in no significant decreases in the maximum PSII quantum efficiency (Fv/Fm) throughout diel exposure periods. Although the quantum efficiency of electron transport (Fq′/Fm′) showed significant reductions early in some experiments, the major response was an increase in Fq′/Fm′ in UVB exposed biofilms. This increase in Fq′/Fm′ was suggestive of a protective vertical migration down into the sediment. Single‐cell and whole biofilm fluorescence imaging demonstrated, for the first time, that motile diatoms are able to detect UVB radiation independently of UVA or photosynthetically active radiation (PAR) and migrate rapidly down (within 15 min) into the sediments to avoid it. This behavioural acclimation mechanism appears to prevent significant accumulation of UVB induced damage to the algae. UVB exposure had no significant effect of biofilm photosynthesis (measured by 14C carbon fixation), but did alter organic carbon allocation patterns, with significantly less new carbon allocated to intracellular storage (glucan) and extracellular colloidal carbohydrate fractions. Significant reductions in the sediment standing stocks of chlorophyll a (Chl a), colloidal carbohydrates, extracellular polymeric substances (EPS) were seen after 7 days of UVB exposure. This study showed that marine intertidal benthic diatoms use a behavioural strategy to avoid exposure to UVB and that this response is effective as a short‐term protection mechanism against UVB damage. However, altered carbon allocation patterns feed forward over time into changes in biofilm biomass and sediment carbohydrate dynamics. This suggests that continual long‐term exposure to UVB may impact on sediment carbon cycling and trophic interactions and on the stabilization of sediments by microalgal biofilms through their production of extracellular carbohydrates.
Nitrogen deposition interacts with climate in affecting production and decomposition rates in Sphagnum mosses
Authors: GERDOL RENATO , PETRAGLIA ALESSANDRO , BRAGAZZA LUCA , IACUMIN PAOLA , BRANCALEONI LISA
Published: June 2007

Increasing rates of atmospheric nitrogen (N) deposition may reduce growth and accelerate decomposition of Sphagnum mosses in bogs. Sphagnum growth and rates of Sphagnum litter decomposition may also vary because of climate change as both processes are controlled by climatic factors. The initial purpose of this study was to assess if growth and litter decomposition of hummock and lawn Sphagnum species varied with increasing N input in a factorial mid‐term (2002–2005) experiment of N and phosphorus (P) addition, in a bog on the southern Alps of Italy. However, as the experimental period was characterized by an exceptional heat wave in summer 2003, we also explored the interacting effects of fertilization and strongly varying climate on growth and decomposition rates of Sphagnum. The heat wave implied strong dehydration of the upper Sphagnum layer even if precipitation in summer 2003 did not differ appreciably from the overall mean. Sphagnum production was somewhat depressed by high levels (3 g m−2 yr−1) of N addition without concomitant addition of P presumably because of nutrient imbalance in the tissues, but production rates were much lower than the overall means in 2003, when no effect of nutrient addition could be observed. Adding N at high level also increased the potential decay of Sphagnum litter. Higher CO2 emission from N‐fertilized litter was due to amelioration of litter chemistry showing lower C/N quotients in the N‐fertilized treatments. Rates of CO2 emission from incubated litter also were more strongly affected by water content than by nutrient status, with practically no CO2 emission detected when litter was dry. We conclude that higher rates of atmospheric N availability input may depress Sphagnum growth because of P, and presumably potassium, (co‐)limitation. Higher N availability is also expected to promote potential decay of Sphagnum litter by ameliorating litter chemistry. However, both effects are less pronounced if the growing Sphagnum apex and the underlying senescing tissues dry out.
Reduced‐effort schemes for monitoring butterfly populations
Authors: ROY D. B. , ROTHERY P. , BRERETON T.
Published: June 2007

Butterflies are one of the few insect groups that can be monitored effectively and have the potential to develop national and Europe‐wide trends in abundance.

For 20 widespread butterfly species, we assess the relative efficiency of reduced‐effort schemes compared to the existing design and estimate the number of sites required to detect changes of given magnitudes over specified periods of time.

A scheme restricted to three counts during July and August requires twice as many monitored sites on average to achieve comparable precision to the existing 26‐week scheme in the United Kingdom. Such a scheme requires 430 monitoring sites on average to achieve 80% power (5% significance level) for detecting a 25% decline in abundance over 10 years.

Such a reduced‐effort scheme may also mean that volunteers are more willing to record in areas where they are likely to see only a few individuals of a few common species (such as on intensively farmed areas). This could potentially help to ensure that butterfly monitoring schemes achieve a more even geographical coverage and less of a bias towards areas rich in butterflies.

Synthesis and applications. Schemes with few sampling visits per year are cost‐effective for expanding butterfly monitoring across Europe, and can be applied to national monitoring programmes and lead to effective assessment of continent‐wide trends in populations.
Stress ulcer prophylaxis for non‐critically ill patients on a teaching service
Authors: Hwang Kevin O. , Kolarov Sanja , Cheng Lee , Griffith Rebecca A.
Published: June 2007

Rationale  Doctors frequently give non‐critically ill patients unjustified stress ulcer prophylaxis (SUP). It is unknown if this practice also occurs during residency training.

Objective  To evaluate the pattern of SUP given to non‐critically ill medical patients on the teaching service of an internal medicine residency programme.

Methods  This was a retrospective cohort study of non‐critically ill adults admitted to the internal medicine teaching service of a community hospital from August 2003 to July 2004. We assessed receipt of SUP, association of SUP with risk factors for stress ulcer bleeding; appropriateness of SUP according to evidence‐based criteria; and incidence of stress ulcer bleeding.

Results  Of the 774 patient records reviewed, 545 were included in the study. The average age was 55.4 years. Patients were more likely to receive SUP if they had more risk factors for stress ulcer bleeding (P < 0.001). Overall, 54.9% (299 of 545) of patients received SUP. Of these 299 patients, at least 58.5% did not warrant SUP, depending on the criteria used. Of the entire cohort of 545 non‐critically ill patients, 32.1% to 54.9% received unjustified SUP, depending on the criteria applied. There were no cases of stress ulcer bleeding.

Conclusions  Many non‐critically ill patients on the teaching service received unjustified SUP, suggesting the need for institutional protocols and educational interventions to promote evidence‐based practice during residency training.
Application of classification tree and logistic regression for the management and health intervention plans in a community‐based study
Authors: Teng Ju‐Hsi , Lin Kuan‐Chia , Ho Bin‐Shenq
Published: June 2007

Background  A community‐based aboriginal study was conducted and analysed to explore the application of classification tree and logistic regression.

Methods  A total of 1066 aboriginal residents in Yilan County were screened during 2003–2004. The independent variables include demographic characteristics, physical examinations, geographic location, health behaviours, dietary habits and family hereditary diseases history. Risk factors of cardiovascular diseases were selected as the dependent variables in further analysis.

Results  The completion rate for heath interview is 88.9%. The classification tree results find that if body mass index is higher than 25.72 kg m−2 and the age is above 51 years, the predicted probability for number of cardiovascular risk factors ≥3 is 73.6% and the population is 322. If body mass index is higher than 26.35 kg m−2 and geographical latitude of the village is lower than 24°22.8′, the predicted probability for number of cardiovascular risk factors ≥4 is 60.8% and the population is 74. As the logistic regression results indicate that body mass index, drinking habit and menopause are the top three significant independent variables.

Conclusions  The classification tree model specifically shows the discrimination paths and interactions between the risk groups. The logistic regression model presents and analyses the statistical independent factors of cardiovascular risks. Applying both models to specific situations will provide a different angle for the design and management of future health intervention plans after community‐based study.
Exploring the challenges and successes of the Lecturer Practitioner role using a stakeholder evaluation approach
Authors: Hancock Helen , Lloyd Hilary , Campbell Steve , Turnock Chris , Craig Stephen
Published: June 2007

Rationale  Plans for NHS reform include strategies to reduce the gap between theory and the realities of clinical practice, with the aim of improving patient care. The role of Lecturer Practitioners (LPs) as educators for nurses who ‘bridge’ the theory–practice gap forms a central part of this strategy. Given the amount of investment in the role and its potential, this study sought to evaluate the impact of the LP role within the education and practice setting from the perspective of key stakeholders.

Methodology  The study, which included five LPs from a range of backgrounds, followed the principles of stakeholder evaluation. Each LP and their line manager identified six informants who were familiar with the LP’s role. The total sample consisted of 36 participants. Semi‐structured interviews were used to gain the perceptions of stakeholders about the LP role. The emerging themes were then discussed, consensus reached, and a collaborative project report produced.

Findings  The findings were derived from the perceptions of the stakeholders. Minimally interpretive analysis of the data resulted in identification of five themes: (i) general overview of LP’s individual qualities; (ii) preconceived notions of the post; (iii) reality of the post; (iv) areas of concern; and (v) developing the role.

Conclusions  The findings indicated that the LP role provides a credible and valuable link between theory and practice and, as such, is an important contribution to the modernization agenda of the NHS. It was apparent, however, that there are a number of areas in which developments are needed, and that organizational and individual actions are necessary in order to achieve the most from these posts.
GhDET2, a steroid 5α‐reductase, plays an important role in cotton fiber cell initiation and elongation
Authors: Luo Ming , Xiao Yuehua , Li Xianbi , Lu Xiaofeng , Deng Wei , Li Demou , Hou Lei , Hu Mingyu , Li Yi , Pei Yan
Published: June 2007

Cotton (Gossypium hirsutum L.) fibers, one of the most important natural raw materials for textile industry, are highly elongated trichomes from epidermal cells of cotton ovules. DET2, an Arabidopsis steroid 5d‐reductase, is considered to catalyze a major rate‐limiting in brassinosteroid (BR) biosynthesis. To understand the role of BRs in cotton fiber development, GhDET2, which putatively encodes a steroid 5α‐reductase by sequence comparison, was cloned from developing fiber cells. In vitro assessment of GhDET2 protein activity confirmed that GhDET2 encodes a functional steroid 5α‐redutase. High levels of GhDET2 transcript were detected during the fiber initiation stage and the fiber rapid elongation stage. Antisense‐mediated suppression of GhDET2 inhibited both fiber initiation and fiber elongation. Similarly, treating cultured ovules with finasteride, a steroid 5α‐reductase inhibitor, reduced fiber elongation. Inhibition of fiber cell elongation by expression of antisense GhDET2 or the finasteride treatment could be reversed by epibrassinolide, a biologically active BR. Furthermore, seed coat‐specific expression of GhDET2 increased fiber number and length. Therefore, GhDET2 and BRs play a crucial role in the initiation and elongation of cotton fiber cells, suggesting that modulation of BR biosynthesis factors may improve fiber quality or yield.
Identification of a novel HLA‐B*40 allele, HLA‐B*4071, by sequence‐based typing
Authors: Park J. , Kwon O.‐J. , Hong S.‐A. , Kwon S.‐Y. , Cho N.‐S.
Published: June 2007

HLA‐B*4071 allele shows six nucleotides difference from B*4005 allele in exon 3 at nucleotides 419A>T, 420C>A, 463C>A, 477C>G, 486G>C and 527A>T, resulting in three amino acid changes Tyr116Leu, Arg131Ser and Glu152Val.
Relative predispositional effects of HLA class II DRB1‐DQB1 haplotypes and genotypes on type 1 diabetes: a meta‐analysis
Authors: Thomson G. , Valdes A. M. , Noble J. A. , Kockum I. , Grote M. N. , Najman J. , Erlich H. A. , Cucca F. , Pugliese A. , Steenkiste A. , Dorman J. S. , Caillat‐Zucman S. , Hermann R. , Ilonen J. , Lambert A. P. , Bingley P. J. , Gillespie K. M. , Lernmark Å. , Sanjeevi C. B. , Rønningen K. S. , Undlien D. E. , Thorsby E. , Petrone A. , Buzzetti R. , Koeleman B. P. C. , Roep B. O. , Saruhan‐Direskeneli G. , Uyar F. A. , Günoz H. , Gorodezky C. , Alaez C. , Boehm B. O. , Mlynarski W. , Ikegami H. , Berrino M. , Fasano M. E. , Dametto E. , Israel S. , Brautbar C. , Santiago‐Cortes A. , Frazer de Llado T. , She J.‐X. , Bugawan T. L. , Rotter J. I. , Raffel L. , Zeidler A. , Leyva‐Cobian F. , Hawkins B. R. , Chan S. H. , Castano L. , Pociot F. , Nerup J.
Published: June 2007

The direct involvement of the human leukocyte antigen class II DR‐DQ genes in type 1 diabetes (T1D) is well established, and these genes display a complex hierarchy of risk effects at the genotype and haplotype levels. We investigated, using data from 38 studies, whether the DR‐DQ haplotypes and genotypes show the same relative predispositional effects across populations and ethnic groups. Significant differences in risk within a population were considered, as well as comparisons across populations using the patient/control (P/C) ratio. Within a population, the ratio of the P/C ratios for two different genotypes or haplotypes is a function only of the absolute penetrance values, allowing ranking of risk effects. Categories of consistent predisposing, intermediate (‘neutral’), and protective haplotypes were identified and found to correlate with disease prevalence and the marked ethnic differences in DRB1‐DQB1 frequencies. Specific effects were identified, for example for predisposing haplotypes, there was a statistically significant and consistent hierarchy for DR4 DQB1*0302s: DRB1*0405 =*0401 =*0402 > *0404 > *0403, with DRB1*0301 DQB1*0200 (DR3) being significantly less predisposing than DRB1*0402 and more than DRB1*0404. The predisposing DRB1*0401 DQB1*0302 haplotype was relatively increased compared with the protective haplotype DRB1*0401 DQB1*0301 in heterozygotes with DR3 compared with heterozygotes with DRB1*0101 DQB1*0501 (DR1). Our results show that meta‐analyses and use of the P/C ratio and rankings thereof can be valuable in determining T1D risk factors at the haplotype and amino acid residue levels.
The PTPN22 promoter polymorphism –1123G>C association cannot be distinguished from the 1858C>T association in a Norwegian rheumatoid arthritis material
Authors: Viken M. K. , Olsson M. , Flåm S. T. , Førre Ø. , Kvien T. K. , Thorsby E. , Lie B. A.
Published: June 2007

The protein tyrosine phosphatase nonreceptor 22 (PTPN22) gene has, during the last 2 years, been recognized as a susceptibility gene for numerous autoimmune diseases, including rheumatoid arthritis (RA) and type 1 diabetes. An association between the exonic 1858C>T single nucleotide polymorphism (SNP) and RA has repeatedly been replicated in several Caucasian populations. The SNP is not associated with autoimmune diseases in Asian populations, as the 1858T allele is almost absent. Recently, a promoter polymorphism –1123G>C was proposed to be associated with acute‐onset type 1 diabetes in Japanese and Korean populations. Furthermore, in Caucasian populations, the presence of additional PTPN22 risk variants has been suggested, indicating that the 1858C>T risk variant cannot explain the entire disease association observed in the region. In this study, we wanted to jointly address and integrate these separate findings to further elucidate the association between the PTPN22 gene and RA in a Norwegian material of 861 RA patients and 559 healthy controls. Our results revealed that the strength of the association with the PTPN22 promoter polymorphism, −1123G>C, is analogous to that observed for 1858C>T. As the −1123G>C variant is also polymorphic in Asian populations, our data underpin the need to further explore the association between this variant and autoimmune diseases in different populations.
Oxygen‐induced changes in the redox state of the cytochrome b559 in photosystem II depend on the integrity of the Mn cluster
Authors: Mamedov Fikret , Gadjieva Rena , Styring Stenbjörn
Published: June 2007

The effect of oxygen and anaerobiosis on the redox properties of Cyt b559 was investigated in PSII preparations from spinach with different degree of disintegration of the donor side. Comparative studies were performed on intact PSII membranes and PSII membranes that were deprived of the 18‐kDa peripheral subunit (0.25 NaCl washed), the 18‐ and 24‐kDa peripheral subunits (1 M NaCl washed), the 18‐, 24‐ and 33‐kDa peripheral subunits (1.2 M CaCl2 washed), Cl depleted and after complete depletion of the Mn cluster (Tris washed). In active PSII centers, about 75% of Cyt b559 was found in the high‐potential form and the rest in the intermediate potential form. With decomposition of the donor side, the intermediate potential form started to dominate, reaching more than 90% after Tris treatment. The oxygen‐dependent conversion of the intermediate potential form of Cyt b559 into the low‐potential and high‐potential forms was only observed after treatments that directly affect the Mn cluster. In PSII membranes, deprived of all three extrinsic subunits (CaCl2 treatment), 21% of the intermediate potential form was converted into the low‐potential form and 14% into the high‐potential form by the removal of oxygen. In Tris‐washed PSII membranes, completely lacking the Mn cluster, this conversion amounted to 60 and 33%, respectively. In intact PSII membranes, the oxygen‐dependent conversion did not occur. The possible physiological role of this oxygen‐dependent behavior of the Cyt b559 redox forms during the assembly/photoactivation cycle of PSII is discussed.
Transglutaminase activity changes during the hypersensitive reaction, a typical defense response of tobacco NN plants to TMV
Authors: Del Duca Stefano , Betti Lucietta , Trebbi Grazia , Serafini‐Fracassini Donatella , Torrigiani Patrizia
Published: June 2007

The occurrence of glutamyl polyamines (PAs) and changes in activity and levels of transglutaminase (TGase, EC 2.3.2.13), the enzyme responsible for their synthesis, are reported during the progression of the hypersensitive reaction (HR) of resistant NN tobacco plants (Nicotiana tabacum L. cv. Samsun) to tobacco mosaic virus (TMV). Mature leaves of tobacco were collected over 0–72 h after inoculation with TMV or phosphate buffer (mock). In vivo synthesis of polyamine glutamyl derivatives (glutamyl PAs), catalyzed by TGase activity, was evaluated after supplying labeled putrescine (Pu, a physiological substrate of TGase) to leaves. Results show that, starting from 24 h, mono‐(γ‐glutamyl)‐Pu and bis‐(γ‐glutamyl)‐Sd were recovered in TMV‐inoculated samples but not in mock‐inoculated ones; 2 days later, in the former, the amount of glutamyl derivatives further increased. An in vitro radiometric assay showed that, in TMV‐inoculated leaves, TGase activity increased from 24 h onwards relative to mock controls. An immunoblot analysis with AtPng1p polyclonal antibody detected a 72‐kDa protein whose amount increased at 72 h in TMV‐inoculated leaves and in the lesion‐enriched areas. A biotin‐labeled cadaverine incorporation assay showed that TGase activity occurred in S1 (containing soluble proteins), S2 (proteins released by both cell walls and membranes) and S3 (membrane intrinsic proteins) fractions. In S3 fraction, where changes were the most relevant, TGase activity was enhanced in both mock‐inoculated and TMV‐inoculated samples, but the stimulation persisted only in the latter case. These data are discussed in the light of a possible role of TGase activity and glutamyl PAs in the defense against a viral plant pathogen.
The impact of long‐term haemofiltration (continuous veno‐venous haemofiltration) on cell‐mediated immunity during endotoxaemia
Authors: Toft P. , Nilsen B. U. , Bollen P. , Lillevang S. , Olsen K. E. , Brøchner A. C. , Larsen N. H.
Published: June 2007

Background:  Increased survival with high‐volume continuous veno‐venous haemofiltration (CVVH) has been demonstrated in critically ill patients. This may be the result of intensified blood purification or an effect on the immune system. We hypothesized that CVVH modifies the cell‐mediated immunity. We investigated the effect of high‐volume CVVH for 24 h on the cell‐mediated immunity following endotoxin infusion.

Methods:  Thirty pigs were divided into three groups. Ten pigs received 30 μg/kg of Escherichia coli endotoxin. These pigs were treated with CVVH (replacement 35 ml/kg/h) over the following 24 h. Ten pigs received the same bolus of endotoxin and ten pigs served as a control group. The adhesion molecules CD18, CD44 and CD62L and the ability to respond with an oxidative burst were measured. The number of neutrophils was counted in blood and lung tissue. The lymphoproliferative response and cytokines interleukin‐6 and interleukin‐10 were measured.

Results:  The infusion of endotoxin was followed by initial granulocytopenia and, later, granulocytosis, activation of CD18 and CD62L, and increased oxidative burst. The cytokine level was increased. CVVH had no effect on the adhesion molecules or cytokine level and did not reduce the number of granulocytes in the lung significantly. CVVH, however, reduced the oxidative burst activity of neutrophils after 2 h of treatment.

Conclusion:  In the first few hours after endotoxaemia, high‐volume CVVH reduced the oxidative burst activity of neutrophils. However, in the long term, CVVH was unable to modify the endotoxin‐induced changes in cell‐mediated immunity.
Scandinavian Clinical Practice Guidelines on the diagnosis, management and follow‐up of anaphylaxis during anaesthesia*
Authors: Kroigaard M. , Garvey L. H. , Gillberg L. , Johansson S. G. O. , Mosbech H. , Florvaag E. , Harboe T. , Eriksson L. I. , Dahlgren G. , Seeman‐Lodding H. , Takala R. , Wattwil M. , Hirlekar G. , Dahlén B. , Guttormsen A. B.
Published: June 2007

The present approach to the diagnosis, management and follow‐up of anaphylaxis during anaesthesia varies in the Scandinavian countries. The main purpose of these Scandinavian Clinical Practice Guidelines is to increase the awareness about anaphylaxis during anaesthesia amongst anaesthesiologists. It is hoped that increased focus on the subject will lead to prompt diagnosis, rapid and correct treatment, and standardised management of patients with anaphylactic reactions during anaesthesia across Scandinavia.

The recommendations are based on the best available evidence in the literature, which, owing to the rare and unforeseeable nature of anaphylaxis, mainly includes case series and expert opinion (grade of evidence IV and V).

These guidelines include an overview of the epidemiology of anaphylactic reactions during anaesthesia. A treatment algorithm is suggested, with emphasis on the incremental titration of adrenaline (epinephrine) and fluid therapy as first‐line treatment.

Recommendations for primary and secondary follow‐up are given, bearing in mind that there are variations in geography and resources in the different countries. A list of National Centres from which anaesthesiologists can seek advice concerning follow‐up procedures is provided. In addition, an algorithm is included with advice on how to manage patients with previous suspected anaphylaxis during anaesthesia. Lastly,Appendix 2provides an overview of the incidence, mechanisms and possibilities for follow‐up for some common drug groups.
Comparison of effects of propofol and midazolam at sedative concentrations on sympathetic tone generation in the isolated spinal cord of neonatal rats
Authors: Ho C.‐M. , Tarng G.‐W. , Su C.‐K.
Published: June 2007

Background:  Propofol and midazolam are common sedatives for critically ill patients. Little is known about the effects of propofol and midazolam on central sympathetic activity when drug concentrations in extracellular milieu are under precise control. Previous work using an in vitro neonatal rat splanchnic nerve–spinal cord preparation has demonstrated that tonic sympathetic activity is generated spontaneously in the thoracic spinal cord. The aim of this study was to investigate the concentration effects of propofol and midazolam on spinally generated sympathetic activity.

Methods:  Using an in vitro neonatal rat splanchnic nerve–spinal cord preparation that allows the precise control of drug concentrations, the central sympathetic effects elicited by the application of propofol (10–640 μm) and midazolam (10–640 μm) were compared.

Results:  There was a prompt decrease in sympathetic activity on application of propofol or midazolam in a concentration‐dependent manner. A significant decrease in sympathetic activity was observed on application of propofol at 80–640 μm; however, the application of propofol at 10–40 μm caused only a slight alteration in activity. The sympathetic activity was not altered significantly by 10 μm of midazolam, but the application of midazolam at 20–640 μm caused a significant decrease in activity. Thus, in these experimental conditions, the minimum concentration of propofol causing a significant decrease in sympathetic activity was 80 μm and that of midazolam was 20 μm.

Conclusions:  The current findings suggest that the administration of 9–19 μm of propofol or 0.7–0.9 μm of midazolam, the clinically relevant concentrations for sedation, does not alter central sympathetic outflow at the spinal cord level. However, propofol at a concentration of 86 μm, which could be achieved by a single‐bolus loading dose to induce sedation, depresses central sympathetic activity.
The NO donor SIN‐1 improves intestinal–arterial Pco2 gap in experimental endotoxemia: an animal study
Authors: Siegemund M. , Van Bommel J. , Sinaasappel M. , Schwarte L. A. , Studer W. , Girard T. , Vollebregt K. , Ince C.
Published: June 2007

Background:  Dysfunction of the microcirculation is a prominent feature of sepsis and endotoxemia. Recently, it has been shown that microcirculatory alterations are completely reversed by local or systemic application of vasodilators in severely septic patients. Therefore, we investigated the influence of vasodilator therapy on microcirculatory dysfunction of the ileum during endotoxic shock in a prospective, controlled animal study.

Methods:  After baseline measurements, shock was induced in 12 domestic pigs by lipopolysaccharide via the mesenteric vein until the mean arterial pressure fell below 60 mmHg. After 30 min in shock, six animals were resuscitated with either fluid alone (control) or fluid and 2 μg/kg/min of the vasodilator 3‐morpholino‐sydnonimine (SIN‐1). The systemic and regional hemodynamics and oxygenation parameters, tonometric ileal Pco2 and microvascular oxygen pressures (μPo2) (by oxygen‐dependent Pd‐porphyrin phosphorescence) were measured simultaneously.

Results:  The ileal–arterial Pco2 gap increased during shock and the ileal mucosal and serosal μPo2 decreased concurrently. SIN‐1 in addition to fluid resuscitation significantly improved the ileal–arterial Pco2 gap, whereas fluid alone failed to decrease the Pco2 gap. The SIN‐1‐induced improvement in the Pco2 gap was accompanied by an increase in serosal μPo2 above shock levels. Mucosal μPo2 was resuscitated to baseline levels in both groups.

Conclusion:  The application of the vasodilator SIN‐1 in addition to fluid resuscitation improves the ileal–arterial Pco2 gap and mucosal μPo2, together with a moderate increase in serosal μPo2, after endotoxic shock. This finding is consistent with the concept that vasodilators may correct pathologic flow distribution within the intestinal wall.
Oscillation frequency of skin microvascular blood flow is associated with mortality in critically ill patients
Authors: Knotzer H. , Maier S. , Dünser M. , Stadlbauer K. H. , Ulmer H. , Pajk W. , Hasibeder W. R.
Published: June 2007

Background:  Microcirculatory dysfunction has been hypothesized to play a key role in the pathophysiology of multiple organ failure and, consequently, patient outcome. The objective of this study was to investigate the differences in reactive hyperemia response and oscillation frequency in surviving and non‐surviving patients with multiple organ dysfunction syndrome.

Methods:  Twenty‐nine patients (15 survivors; 14 non‐survivors) with two or more organ failures were eligible for study entry. All patients were hemodynamically stabilized, and demographic and clinical data were recorded. A laser Doppler flowmeter was used to measure the cutaneous microcirculatory response. Reactive hyperemia and oscillatory changes in the Doppler signal were measured during 3 min before and after a 5‐min period of forearm ischemia.

Results:  Non‐survivors demonstrated a significantly higher multiple organ dysfunction score when compared with survivors (P= 0.004). Norepinephrine administration was higher in non‐survivors (P= 0.018). Non‐survivors had higher arterial lactate levels (P= 0.046), decreased arterial pH levels (P= 0.001) and decreased arterial Po2 values (P= 0.013) when compared with survivors. A higher oscillation frequency of the skin microvasculature at rest (P= 0.033) and after an ischemic stimulus (P= 0.009) was observed in non‐survivors. The flow motion frequency observed in reactive hyperemia was associated with the severity of multiple organ dysfunction (P= 0.009) and, although not statistically significant, with the arterial lactate concentration (P= 0.052).

Conclusion:  Increased skin microvascular oscillation frequency at rest and in the hyperemic state after an ischemic stimulus is associated with increased mortality in patients suffering from multiple organ dysfunction. The underlying mechanism could be a response of the skin microvasculature to an impaired oxygen utilization of the skin tissue.
Computed Tomography (CT) of the Lungs of the Dog Using a Helical CT Scanner, Intravenous Iodine Contrast Medium and Different CT Windows
Authors: Cardoso L. , Gil F. , Ramírez G. , Teixeira M. A. , Agut A. , Rivero M. A. , Arencibia A. , Vázquez J. M.
Published: June 2007

The aim of this study was to determine the accuracy of helical computed tomography (CT) for visualizing pulmonary parenchyma and associated formations in normal dogs. CT scan was performed by using intravenous contrast medium and by applying different types of CT windows: soft tissue and lung windows, and high‐resolution computed tomography of the lung. This technique allowed, especially with lung window types, a good view of the parenchyma, bronchial tree, vascular structures and pleural cavity. The selected images, with high anatomical quality and tissue contrast, may be a reference for future clinical studies of this organ. Thus, helical CT is a promising non‐invasive method of diagnosing a wide variety of pulmonary diseases in dogs.
Expression of Neuronal Nitric Oxide Synthase in the Pancreas of the Sheep
Authors: Arciszewski M. B.
Published: June 2007

In numerous mammals, nitric oxide (NO) influences the activity of the exocrine and endocrine pancreas. In this study, immunocytochemistry was utilized to investigate the expression of neuronal nitric oxide synthase (nNOS) in the pancreas of sheep. In double immunocytochemical staining, the co‐localization of nNOS with vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) or substance P (SP) was studied. The presence of nNOS was confined to the intrapancreatic neurones (9.6 ± 1.3%) as well as to nerve fibres of the endocrine pancreas and intrapancreatic ganglia. nNOS‐immunoreactive (IR) neurones were round and oval in shape and predominantly (83.3 ± 2.6%) belonged to the middle‐size group (25–50 μm). Numerous, fine islets supplying nNOS‐IR nerve terminals were devoid of VIP, SP or NPY. Moderately numerous, non‐varicose nNOS‐IR nerve fibres of intrapancreatic ganglia frequently expressed VIP or NPY, but not SP; 2.2 ± 0.6% of nNOS‐IR intrapancreatic neurones displayed lack of VIP, whereas 7.5 ± 0.8% were VIP‐IR. All nNOS‐IR neurones were devoid of SP. The frequencies of nNOS‐IR/NPY‐IR and nNOS‐IR/NPY‐negative intrapancreatic neurones were 2.2 ± 0.4% and 6.1 ± 1.1%, respectively. Comparison with other mammals indicated that nitrergic innervation of the ovine pancreas is species‐determined and may be a reflection of the ruminants’ digestion specificity. The possible origin of nNOS‐IR nerve fibres and functional significance of NO in the pancreas of sheep were discussed.
Casual Discovery of a Thoracic Tumour Showing Histological Features of Undifferentiated Pleomorphic Sarcoma in a Male Wistar Laboratory Rat
Authors: Lavranos G. , Paschalis G. , Angelopoulou R. , Karandrea D. , Goutas N.
Published: June 2007

Sarcomas are neoplasms of mesenchymal origin, with a predominant cell population mimicking the organization of various soft tissues and/or bones. Previous categorizations also included the possibility of the presence of tissue macrophage‐like (histiocytes) neoplasm cells, in a tumour described as malignant fibrous histiocytoma, but this group has been considered as a variety of undifferentiated pleomorphic sarcomas. Although this kind of malignancy is not rare in humans, only few cases have been reported in laboratory animals. We report an unusual single case of spontaneous tumour growth, detected by casual observation, in the left thoracic area of an 18‐month‐old male laboratory Wistar rat. Both this individual and his ancestors were not exposed to any known carcinogenic substance or radiation, thus suggesting the development of the neoplasm as a spontaneous event. The mass was extracted surgically under general anaesthesia, and slices were examined histologically and immunohistochemically, using photon microscopy. The pathologist reported the presence of a combination of fibroblasts and undifferentiated mesenchymal cells arranged in a storiform pattern. Immunohistochemistry was performed on the tissue using specific antibodies for several proliferation (Ki‐67) and differentiation (S‐100, CD‐34, CD‐68, pan‐keratin, desmin and smooth muscle actin‐SMA) markers. Positive reaction was observed for S‐100, Ki‐67, CD‐68, desmin and SMA (limited) but not for CD‐34 or cytokeratin.
Effect of a gluten‐free diet on growth and small‐bowel histology in children with celiac disease in India
Authors: Yachha Surender K , Srivastava Anshu , Mohindra Samir , Krishnani Narendra , Aggarwal Rakesh , Saxena Anita
Published: June 2007

Background and Aim:  Follow‐up studies on growth and histological recovery of children with celiac disease (CD) while on a gluten‐free diet (GFD) are lacking from Asia. We therefore assessed the effects of this diet.

Methods:  Forty‐two children with CD were enrolled. Weight and height were expressed as weight for height (WfH) and height standard deviation scores (HSDS), respectively. Twenty‐five children had repeated duodenal biopsies after 1–2 years and 14 had a third biopsy after 3–7 years of GFD. Compliance was checked by regular interview and IgA antiendomysial antibody estimation (EMA).

Results:  At diagnosis (n = 25), mean HSDS was −3.3 ± 1.6 with 76% having a HSDS of <−2; 60% were undernourished (WfH mean 81.6 ± 5.7). Over a mean follow up of 3.7 years, HSDS improved to −1.3 ± 1.7 and 84% cases achieved normal nutrition. Mean height velocity was 13.9 cm during first year and 5.6 cm in subsequent years. Small‐bowel biopsies at diagnosis showed subtotal villous atrophy (Marsh IIIb) in 18 (72%) and partial villous atrophy (Marsh IIIa) in seven (28%) patients. Repeat biopsy at 1–2 years showed shift from subtotal to partial villous atrophy in 94% (n = 17/18) and normalization in one patient. In patients with Marsh IIIa improvement of partial villous atrophy was observed in all. Immunoglobulin A endomysial antibody was negative in 81%. Repeat biopsies at 5 years of GFD showed improvement to Marsh I–II, but none normalized.

Conclusion:  The majority of children with CD show normalization of nutrition and growth after GFD. Small‐bowel histology improves markedly but does not normalize even after 5 years of GFD.
Antiviral action of interferon‐α against hepatitis C virus replicon and its modulation by interferon‐γ and interleukin‐8
Authors: Jia Yintang , Wei Lai , Jiang Dong , Wang Jianghua , Cong Xu , Fei Ran
Published: June 2007

Background and Aim:  Interferon‐α (IFN‐α) based therapy is the main treatment used to control hepatitis C virus (HCV) infection. The aim of this study was to understand the mechanisms of IFN‐α inhibition of HCV replication and the resistance of HCV to IFN‐α therapy, and improve the efficiency of HCV treatment.

Methods:  The inhibitory effects of IFN‐α on a HCV replicon system were examined and the potential regulatory effects of interferon‐γ (IFN‐γ) and interleukin‐8 (IL‐8) on the antiviral actions of IFN‐α were also investigated in this report.

Results:  The results showed that IFN‐α can effectively inhibit the replication of HCV replicon. Pretreatment of HCV replicon cells with IFN‐γ could significantly potentiate the inhibitory effects of IFN‐α on the HCV replicon. Direct addition of IL‐8 to the culture medium of HCV replicon cells could partially rescue the HCV replicon from the inhibition of IFN‐α, which may be the result of IL‐8 down‐regulation of interferon‐stimulated genes.

Conclusion:  Our study demonstrated that IFN‐γ has synergistic antiviral effects with IFN‐α; whereas IL‐8 can attenuate the anti‐HCV actions of IFN‐α and is associated with HCV resistance to interferon‐α therapy.
Further validation of magnifying chromocolonoscopy for differentiating colorectal neoplastic polyps in a health screening center
Authors: Emura Fabian , Saito Yutaka , Taniguchi Makoto , Fujii Takahiro , Tagawa Kazumi , Yamakado Minoru
Published: June 2007

Background and Aim:  The accuracy of conventional colonoscopy to differentiate neoplastic and non‐neoplastic polyps is limited, justifying a biopsy for histologic analysis. Magnifying chromocolonoscopy has emerged as the best tool available for differentiating adenomatous and hyperplastic polyps during colonoscopy; however, magnifying endoscopes are rarely used in endoscopy units. This study aimed to further validate the effectiveness of magnifying chromocolonoscopy in the diagnosis of neoplastic colorectal polyps in a screening center.

Method:  Five hundred average‐risk subjects were randomly divided into two groups: a magnifying chromocolonoscopy group and a conventional chromocolonoscopy group, each of 250 subjects. Lesions were analyzed according to Kudo's classification of pit pattern (types I–V) and additionally subdivided into non‐neoplastic (types I–II) and neoplastic (types III–V). Lesions judged as neoplastic were resected and those judged as non‐neoplastic were left in situ. Only lesions ≤10 mm were included in the study. Resected lesions were analyzed with histopathological examination.

Results:  The overall accuracy of magnifying chromocolonoscopy for differentiating neoplastic lesions (95%, 135 of 142), was significantly higher than that of conventional chromocolonoscopy (84%, 102 of 122; P < 0.01). The accuracy of magnifying chromocolonoscopy for differentiating neoplastic lesions ≤5 mm was 94% (135 of 142), whereas that of conventional chromocolonoscopy was only 78% (69 of 89; P < 0.001). Results were not affected by the macroscopic types.

Conclusion:  Magnifying chromocolonoscopy is superior to conventional chromocolonoscopy for the diagnosis of colorectal neoplastic lesions in the setting of a health testing center.