bluuebunny/crossref_metadata_2025 huggingface dataset:
Guidelines for capsule endoscopy: diagnoses will be missed
Authors: MAKINS R. , BLANSHARD C.
Published: June 2006

Background

Capsule endoscopy represents a significant advance in the investigation of intestinal disease. National Institute of Health and Clinical Excellence, European Society of Gastrointestinal Endoscopy and American Society for Gastrointestinal Endoscopy guidelines support capsule endoscopy in obscure GI bleeding, Crohn's disease and the evaluation of non‐steroidal anti‐inflammatory drug side‐effects, polyposis syndromes and coeliac disease.

Aim

To determine whether the application of guidelines leads to missed diagnoses that would have been made if less stringent indications were adopted.

Methods

Retrospective analysis of 100 consecutive unselected capsule endoscopy examinations at Homerton Hospital, from October 2003 to November 2005. All referrals accepted following traditional investigations. Indications and findings were recorded. Comparison made as to whether diagnoses would have been missed if guidelines had been followed and capsule endoscopy not performed.

Results

Among the subjects 37 patients were children and 55 were male. Indications included recurrent bleeding and anaemia, assessment of Crohn's disease, ‘others’, i.e. assessment of coeliac disease, Peutz‐Jehgers syndrome, Blue Rubber Bleb syndrome or non‐specific abdominal pain. In patients with coeliac disease, widespread enteropathy was confirmed, with additional diagnoses of delayed gastric emptying and colitis. For those with abdominal pain findings included angiodysplasia, lymphoid hyperplasia and distal small bowel ulcers.

Conclusions

Capsule endoscopy in patients with non‐conventional indications yielded abnormal pathology, such as ulcers and inflammation. If published guidelines had been followed such diagnoses would have been missed.
Randomized trial of rifabutin‐based triple therapy and high‐dose dual therapy for rescue treatment of Helicobacter pylori resistant to both metronidazole and clarithromycin
Authors: MIEHLKE S. , HANSKY K. , SCHNEIDER‐BRACHERT W. , KIRSCH C. , MORGNER A. , MADISCH A. , KUHLISCH E. , BÄSTLEIN E. , JACOBS E. , BAYERDÖRFFER E. , LEHN N. , STOLTE M.
Published: June 2006

Background

The clinical management of Helicobacter pylori infected patients who failed standard eradication therapies remains a challenge.

Aim

To investigate the efficacy of rifabutin‐based triple therapy and high‐dose dual therapy for rescue treatment of H. pylori, and the correlation between cytochrome P450 2C19 (CYP2C19) polymorphisms and treatment outcome.

Methods

Patients infected with H. pylori resistant to both metronidazole and clarithromycin (n = 145) were randomized to either esomeprazole 20 mg, rifabutin 150 mg and amoxicillin 1 g, each given b.d. for 7 days (ERA), or to omeprazole 40 mg and amoxicillin 1000 mg, each given t.d.s. for 14 days (OA). Crossover therapy was offered in cases of persistent infection. CYP2C19 polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphism.

Results

Intention‐to‐treat and per‐protocol eradication rates were: ERA 74% (62.4–83.6) and 78% (66.7–87.3); high‐dose OA 70% (57.5–79.7) and 75% (62.5–84.5). Crossover therapy was successful in seven of 10 patients with ERA and in eight of 10 patients with OA. Premature discontinuation of treatment occurred in 2% and 5% of patients, respectively. There was only a non‐significant trend to lower eradication rates in homozygous extensive metabolizers.

Conclusions

Triple therapy with esomeprazole, rifabutin and amoxicillin and high‐dose omeprazole/amoxicillin are comparable and effective and safe for rescue therapy of H. pylori regardless of the patient's CYP2C19 genotype.
Systematic review and meta‐analysis: importance of CagA status for successful eradication of Helicobacter pylori infection
Authors: SUZUKI T. , MATSUO K. , SAWAKI A. , ITO H. , HIROSE K. , WAKAI K. , SATO S. , NAKAMURA T. , YAMAO K. , UEDA R. , TAJIMA K.
Published: June 2006

Background

Some, but not all studies have provided evidence that the CagA status of Helicobacter pylori strains is a predictive factor for the outcome of eradication therapy.

Aim

To clarify the association between CagA status and eradication outcome.

Methods

We included studies reporting the numbers of successful and failed cases in H. pylori‐eradication therapy according to the CagA status. Fourteen studies (1529 patients) were included of 325 articles identified in the search. The pooled risk ratio for H. pylori‐eradication failure in CagA‐negative relative to CagA‐positive strains and the pooled risk difference in eradication success between the two groups were used as summary statistics. Meta‐regression was used for examining the source of heterogeneity.

Results

The summary risk ratio for eradication failure in CagA‐negative relative to CagA‐positive was 2.0 (95% CI: 1.6–2.4, P < 0.001), corresponding with the summary risk difference for eradication success between the groups of 11% (95% CI: 3–19%, P = 0.011). Meta‐regression analysis demonstrated that usage of polymerase chain reaction examination for CagA status and a high proportion of non‐ulcer dyspepsia patients were factors for heterogeneity among studies.

Conclusions

Our meta‐analysis confirmed the importance of the presence of CagA as a predictor for successful eradication of H. pylori.
Therapeutic hypothermia after cardiac arrest: a survey of practice in intensive care units in the United Kingdom
Authors: Laver S. R. , Padkin A. , Atalla A. , Nolan J. P.
Published: June 2006

A telephone survey was carried out on the use of hypothermia as part of the management of unconscious patients following cardiac arrest admitted to United Kingdom (UK) intensive care units (ICUs). All 256 UK ICUs listed in the Critical Care Services Manual 2004 were contacted to determine how many units have implemented therapeutic hypothermia for unconscious patients admitted following cardiac arrest, how it is implemented, and the reasons for non‐implementation. Two hundred and forty‐six (98.4%) ICUs agreed to participate. Sixty‐seven (28.4%) ICUs have cooled patients after cardiac arrest, although the majority of these have treated fewer than 10 patients. The commonest reasons given for not using therapeutic hypothermia in this situation are logistical or resource issues, or the perceived lack of evidence or consensus within individual ICU teams.
Emergency Caesarean section: best practice*
Authors: Levy D. M.
Published: June 2006

Good multidisciplinary communication is crucial to the safe management of women requiring non‐elective Caesarean section. Anaesthetists should participate actively in resuscitation of the fetus in utero; relief of aortocaval compression is paramount. Epidural top‐up with levobupivacaine 0.5% is the anaesthetic of choice for women who have been receiving labour epidural analgesia. If epidural top‐up fails to provide bilateral light touch anaesthesia from S5 – T5, a combined spinal‐epidural technique with small intrathecal dose of local anaesthetic is a useful approach. Pre‐eclampsia is not a contra‐indication to single‐shot spinal anaesthesia, which is the technique of choice for most women presenting for Caesarean section without an epidural catheter in situ. Induction and maintenance doses of drugs for general anaesthesia should not be reduced in the belief that the baby will be harmed. Early postoperative observations are geared towards the detection of overt or covert haemorrhage.
Bronchial mucus transport velocity in patients receiving anaesthesia with propofol and morphine or propofol and remifentanil
Authors: Ledowski T. , Hilmi S. , Paech M. J.
Published: June 2006

In vitro morphine does not reduce cilia beat frequency, a key factor determining bronchial mucus transport velocity. There are no reports about the effect of remifentanil on bronchial mucus transport. We compared the bronchial mucus transport velocity in patients having total intravenous anaesthesia with either propofol and morphine, or propofol and remifentanil. Twenty patients scheduled for elective surgery were randomly allocated to the two groups. Fifteen minutes after insertion of the laryngeal mask airway, bronchial mucus transport velocity was assessed by fibreoptic observation of the movement of methylene blue dye applied to the right main bronchus. Compared with morphine, bronchial mucus transport velocity was significantly reduced in patients receiving remifentanil (morphine mean (SD) 9.2 (5.8) vs remifentanil 4.2 (3.0) mm.min−1, p = 0.028). Anaesthesia with remifentanil may lead to significantly impaired bronchociliary clearance in comparison to morphine. This could have clinical implications, in particular in patients at risk.
Which drugs cause preventable admissions to hospital? A systematic review
Authors: Howard R. L. , Avery A. J. , Slavenburg S. , Royal S. , Pipe G. , Lucassen P. , Pirmohamed M.
Published: June 2006

Aims

Previous systematic reviews have found that drug‐related morbidity accounts for 4.3% of preventable hospital admissions. None, however, has identified the drugs most commonly responsible for preventable hospital admissions. The aims of this study were to estimate the percentage of preventable drug‐related hospital admissions, the most common drug causes of preventable hospital admissions and the most common underlying causes of preventable drug‐related admissions.

Methods

Bibliographic databases and reference lists from eligible articles and study authors were the sources for data. Seventeen prospective observational studies reporting the proportion of preventable drug‐related hospital admissions, causative drugs and/or the underlying causes of hospital admissions were selected. Included studies used multiple reviewers and/or explicit criteria to assess causality and preventability of hospital admissions. Two investigators abstracted data from all included studies using a purpose‐made data extraction form.

Results

From 13 papers the median percentage of preventable drug‐related admissions to hospital was 3.7% (range 1.4–15.4). From nine papers the majority (51%) of preventable drug‐related admissions involved either antiplatelets (16%), diuretics (16%), nonsteroidal anti‐inflammatory drugs (11%) or anticoagulants (8%). From five studies the median proportion of preventable drug‐related admissions associated with prescribing problems was 30.6% (range 11.1–41.8), with adherence problems 33.3% (range 20.9–41.7) and with monitoring problems 22.2% (range 0–31.3).

Conclusions

Four groups of drugs account for more than 50% of the drug groups associated with preventable drug‐related hospital admissions. Concentrating interventions on these drug groups could reduce appreciably the number of preventable drug‐related admissions to hospital from primary care.
Fetal hepatic haematopoiesis is modulated by arterial blood flow to the liver
Authors: Kunisaki Shaun M. , Azpurua Humberto , Fuchs Julie R. , Graves Sara C. , Zurakowski David , Fauza Dario O.
Published: June 2006

We describe an as yet unrecognised relationship between fetal hepatic haematopoiesis and arterial blood flow to the liver. To increase hepatic arterial flow, the common bile duct (CBD) was ligated in fetal lambs. Reduction of hepatic arterial flow was accomplished in age‐matched animals by hepatic artery (HA) ligation. Multiple analyses performed before term showed a significant increase in haematopoietic cell density in CBD animals when compared with sham controls and HA animals. In contrast, HA animals demonstrated a decrease in liver haematopoietic activity. Fetal hepatic haematopoiesis is dependent upon arterial blood flow to the liver.
Age changes the diagnostic accuracy of mean profile and nadir growth hormone levels after oral glucose in postoperative patients with acromegaly
Authors: Colao Annamaria , Pivonello Rosario , Cavallo Luigi M. , Gaccione Maria , Auriemma Renata S. , Esposito Felice , Cappabianca Paolo , Lombardi Gaetano
Published: June 2006

Background  This analytical, retrospective study was designed to select cut‐off thresholds of mean GH levels during a diurnal profile and nadir GH levels after oral glucose tolerance test (OGTT) according to age to diagnose surgical remission of acromegaly.

Methods   One hundred forty‐one patients (76 women, aged 44 ± 15 years and 65 men, aged 43 ± 13 years) were included in this study. For the purpose of this study, remission was based on insulin‐like growth factor‐I (IGF‐I) levels in the normal range for age. Diagnostic accuracy was analysed by receiving‐operator characteristics (ROC) curves in the entire series, and in young (20–40 years), middle‐aged (41–60 years) and older patients (> 60 years), separately.

Results   Sixty patients (42·6%) had normal IGF‐I levels after surgery. In the entire series, in young and in middle‐aged patients, the ROC analysis showed that optimum cut‐off for mean GH levels was 2·3 µg/l (diagnostic accuracy range, 94–97%) whereas that for nadir GH after OGTT were, respectively, 0·85, 0·9 and 0·8 µg/l (diagnostic accuracy range, 90–95%). In the older patients, the optimum cut‐off selected for mean GH levels was 1·4 µg/l and that for nadir GH after OGTT was 0·5 µg/l (diagnostic accuracy, 100% for both). The comparative analysis of the ROC curves did not show any significant difference between mean GH and nadir GH after OGTT (P = 0·21).

Conclusions   The criteria currently accepted for diagnosing post‐surgical remission of acromegaly have high diagnostic accuracy only in the patients aged below 60 years. In older patients, lower cut‐offs (i.e. = 1·4 µg/l for fasting GH and = 0·5 µg/l for nadir GH after OGTT) predict normal IGF‐I levels. Mean GH levels during a diurnal profile have similar diagnostic accuracy of nadir GH levels after OGTT. This suggests that OGTT is not necessary to establish surgical cure.
Effects of plant species diversity, atmospheric [CO2], and N addition on gross rates of inorganic N release from soil organic matter
Authors: WEST JASON B. , HOBBIE SARAH E. , REICH PETER B.
Published: June 2006

A significant challenge in predicting terrestrial ecosystem response to global changes comes from the relatively poor understanding of the processes that control pools and fluxes of plant nutrients in soil. In addition, individual global changes are often studied in isolation, despite the potential for interactive effects among them on ecosystem processes. We studied the response of gross N mineralization and microbial respiration after 6 years of application of three global change factors in a grassland field experiment in central Minnesota (the BioCON experiment). BioCON is a factorial manipulation of plant species diversity (1, 4, 9 and 16 prairie species), atmospheric [CO2] (ambient and elevated: 560 μmol mol−1), and N inputs (ambient and ambient +4 g N m−2 yr−1). We hypothesized that gross N mineralization would increase with increasing levels of all factors because of stimulated plant productivity and thus greater organic inputs to soils. However, we also hypothesized that N addition would enhance, while elevated [CO2] and greater diversity would temper, gross N mineralization responses because of increased and reduced plant tissue N concentrations, respectively. In partial support of our hypothesis, gross N mineralization increased with greater diversity and N addition, but not with elevated [CO2]. The ratio of gross N mineralization to microbial respiration (i.e. the ‘yield’ of inorganic N mineralized per unit C respired) declined with greater diversity and [CO2] suggesting increasing limitation of microbial processes by N relative to C in these treatments. Based on these results, we conclude that the plant supply of organic matter primarily controls gross N mineralization and microbial respiration, but that the concentration of N in organic matter input secondarily influences these processes. Thus, in systems where N limits plant productivity these global change factors could cause different long‐term ecosystem trajectories because of divergent effects on soil N and C cycling.
Points, patches, and regions: scaling soil biogeochemical patterns in an urbanized arid ecosystem
Authors: JENERETTE G. DARREL , WU JIANGUO , GRIMM NANCY B. , HOPE DIANE
Published: June 2006

Cities are rapidly growing throughout the world and are altering biologic processes in many regions, with global consequences. Urbanization in the Phoenix, USA metropolitan region has dramatically altered regional ecosystem patterns, but little is known about how these changes have influenced soil organic matter, total nitrogen, and the distribution of nitrogen stable isotopes. Because urban development is a phenomenon occurring at multiple scales, ecological consequences of urbanization will likely differ between individual patches and the entire metropolitan region. To investigate such changes we conducted spatially explicit surveys including three dominant land‐use types in this region: native desert, agriculture, and mesic residential. These data were combined for analysis with previously collected samples from a synoptic regional survey. A landscape scaling approach was implemented to compare the dependence of soil variability on the sampled extent and the uncertainty associated with scaling from points to patches, land‐use types, and the Phoenix metropolitan region. The multiple‐scale analysis of soil properties showed that variation in total soil nitrogen, soil organic matter, andδ5N content of soils differed between patch and regional scales. The majority of variation in the urbanized patch types was exhibited between patches while for the native desert the majority of variation was observed within individual patches. These differences show the impact of urbanization on the scaling relations of ecosystem components. Overall, urbanization in this region appears to have increased soil organic matter by 44%, total nitrogen by 48%, and has elevatedδ15N by 21%.
Ecosystem CO2 production during winter in a Swedish subarctic region: the relative importance of climate and vegetation type
Authors: GROGAN PAUL , JONASSON SVEN
Published: June 2006

General circulation models consistently predict that regional warming will be most rapid in the Arctic, that this warming will be predominantly in the winter season, and that it will often be accompanied by increasing snowfall. Paradoxically, despite the strong cold season emphasis in these predictions, we know relatively little about the plot and landscape‐level controls on tundra biogeochemical cycling in wintertime as compared to summertime.

We investigated the relative influence of vegetation type and climate on CO2 production rates and total wintertime CO2 release in the Scandinavian subarctic. Ecosystem respiration rates and a wide range of associated environmental and substrate pool size variables were measured in the two most common vegetation types of the region (birch understorey and heath tundra) at four paired sites along a 50 km transect through a strong snow depth gradient in northern Sweden.

Both climate and vegetation type were strong interactive controls on ecosystem CO2 production rates during winter. Of all variables tested, soil temperature explained by far the largest amount of variation in respiration rates (41–75%). Our results indicate that vegetation type only exerted an influence on respiration when snow depth was below a certain threshold (∼1 m). Thus, tall vegetation that enhanced snow accumulation within that threshold resulted in more effective thermal insulation from severe air temperatures, thereby significantly increasing respiratory activity. At the end of winter, within several days of snowmelt, gross ecosystem photosynthesis rates were of a similar magnitude to ecosystem respiration, resulting in significant net carbon gain in some instances. Finally, climate and vegetation type were also strong interactive controls on total wintertime respiration, suggesting that spatial variations in maximum snowdepth may be a primary determinant of regional patterns of wintertime CO2 release. Together, our results have important implications for predictions of how the distribution of tundra vegetation types and the carbon balances of arctic ecosystems will respond to climate change during winter because they indicate a threshold (∼1 m) above which there would be little effect of increased snow accumulation on wintertime biogeochemical cycling.
Advanced snowmelt causes shift towards positive neighbour interactions in a subarctic tundra community
Authors: WIPF SONJA , RIXEN CHRISTIAN , MULDER CHRISTA P. H.
Published: June 2006

Positive and negative species interactions are important factors in structuring vegetation communities. Studies in many ecosystems have focussed on competition; however, facilitation has often been found to outweigh competition under harsh environmental conditions. The balance between positive and negative species interactions is known to shift along spatial, temporal and environmental gradients and thus is likely to be affected by climate change.

Winter temperature and precipitation patterns in Interior Alaska are rapidly changing and could lead to warmer winters with a shallow, early melting snow cover in the near future. We conducted snow manipulation and neighbour removal experiments to test whether the relative importance of positive and negative species interactions differs between three winter climate scenarios in a subarctic tundra community. In plots with ambient, manually advanced or delayed snowmelt, we assessed the relative importance of neighbours for survival, phenology, growth and reproduction of two dwarf shrub species. Under ambient conditions and after delayed snowmelt, positive and negative neighbour effects were generally balanced, but when snowmelt was advanced we found overall facilitative neighbour effects on survival, phenology, growth and reproduction of Empetrum nigrum, the earlier developing of the two target species. As earlier snowmelt was correlated with colder spring temperatures and a higher number of frosts, we conclude that plants experienced harsher environmental conditions after early snowmelt and that neighbours could have played an important role in ameliorating the physical environment at the beginning of the growing season.
The relative importance of climatic effects, wildfires and management for future forest landscape dynamics in the Swiss Alps
Authors: SCHUMACHER SABINE , BUGMANN HARALD
Published: June 2006

Forest landscape dynamics result from the complex interaction of driving forces and ecological processes operating on various scales. Projected climate change for the 21st century will alter climate‐sensitive processes, causing shifts in species composition and also bringing about changes in disturbance regimes, particularly regarding wildfires. Previous studies of the impact of climate change on forests have focused mainly on the direct effects of climate. In the present study, we assessed the interactions among forest dynamics, climate change and large‐scale disturbances such as fire, wind and forest management. We used the LandClimmodel to investigate the influence, interactions and the relative importance of these different drivers of landscape dynamics in two case study areas of the European Alps. The simulations revealed that projected future climate change would cause extensive forest cover changes, beginning in the coming decades. Fire is likely to become almost as important for shaping the landscape as the direct effects of climate change, even in areas where major wildfires do not occur under current climatic conditions. The effects of variable wind disturbances and harvesting regimes, however, are less likely to have a considerable impact on forest development compared with the direct effects of climate change coupled with the indirect effects of increased fire activity. We conclude that the joint direct and indirect effects of climate change are likely to have major consequences for mountain forests in the European Alps, including their ability to provide protection against natural hazards.
Using metabolic fingerprinting of plants for evaluating nitrogen deposition impacts on the landscape level
Authors: GIDMAN ELEANOR A. , STEVENS CARLY J. , GOODACRE ROYSTON , BROADHURST DAVID , EMMETT BRIDGET , GWYNN‐JONES DYLAN
Published: June 2006

Nitrogen emissions and atmospheric deposition are globally significant with the potential to alter ecosystem nutrient balance, provoking changes in vegetation composition. Shifts in plant biochemistry are good indicators of nitrogen pollution and have been used to monitor vegetation health. Fourier transform‐infrared (FT‐IR) spectroscopy has previously been shown to be a rapid and relatively inexpensive method for evaluating leaf biochemistry. In the present study, FT‐IR spectra were collected from Galium saxatile samples taken from sites across the United Kingdom. Spectral changes in the tissue samples were correlated with a gradient of N deposition using partial least squares regression analysis. We show that FT‐IR analysis of G. saxatile leaf tissue is an effective way to evaluate nitrogen deposition across the entire UK landscape.
Predicting climate‐induced range shifts: model differences and model reliability
Authors: LAWLER JOSHUA J. , WHITE DENIS , NEILSON RONALD P. , BLAUSTEIN ANDREW R.
Published: June 2006

Predicted changes in the global climate are likely to cause large shifts in the geographic ranges of many plant and animal species. To date, predictions of future range shifts have relied on a variety of modeling approaches with different levels of model accuracy. Using a common data set, we investigated the potential implications of alternative modeling approaches for conclusions about future range shifts and extinctions. Our common data set entailed the current ranges of 100 randomly selected mammal species found in the western hemisphere. Using these range maps, we compared six methods for modeling predicted future ranges. Predicted future distributions differed markedly across the alternative modeling approaches, which in turn resulted in estimates of extinction rates that ranged between 0% and 7%, depending on which model was used. Random forest predictors, a model‐averaging approach, consistently outperformed the other techniques (correctly predicting >99% of current absences and 86% of current presences). We conclude that the types of models used in a study can have dramatic effects on predicted range shifts and extinction rates; and that model‐averaging approaches appear to have the greatest potential for predicting range shifts in the face of climate change.
Lactoferrin decreases pollen antigen‐induced allergic airway inflammation in a murine model of asthma
Authors: Kruzel Marian L. , Bacsi Attila , Choudhury Barun , Sur Sanjiv , Boldogh Istvan
Published: June 2006

Pollen grains contain reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidases and in contact with mucosal surfaces generate superoxide anion (O2•–). In the presence of iron, O2•– may be converted to more reactive oxygen radicals, such as to H2O2 and/or •OH, which may augment antigen‐induced airway inflammation. The aim of the study was to examine the impact of lactoferrin (LF), an iron‐binding protein, on ragweed (Ambrosia artemisiifolia) pollen extract (RWE)‐induced cellular oxidative stress levels in cultured bronchial epithelial cells and accumulation of inflammatory and mucin‐producing cells in airways in a mouse model of allergic airway inflammation. Results show that LF lowered RWE‐induced increase in cellular reactive oxygen species (ROS) levels in bronchial epithelial cells. Most importantly, LF significantly decreased accumulation of eosinophils into airways and subepithelium of intranasally challenged, sensitized mice. LF also prevented development of mucin‐producing cells. Amb a 1, the major allergenic ragweed pollen antigen lacking NAD(P)H oxidase activity, induced low‐grade airway inflammation. When administered along with glucose oxidase (G‐ox), a superoxide‐generating enzyme, Amb a 1 induced robust airway inflammation, which was significantly lowered by LF. Surprisingly, LF decreased also inflammation caused by Amb a 1 alone. Iron‐saturated hololactoferrin had only a marginal effect on RWE‐induced cellular ROS levels and RWE‐ or Amb a 1 plus G‐ox‐induced inflammation. We postulate that free iron in the airways chemically reduces O2•– to more reactive species which augment antigen‐induced inflammation in a mouse model of asthma. Our results suggest the utility of LF in human allergic inflammatory disorders.
Deep genealogies and the mid‐peninsular seaway of Baja California
Authors: Lindell Johan , Ngo Andre , Murphy Robert W.
Published: June 2006

Geological forces and long‐term climate changes can have profound effects on species. Such effects may be manifested in the pattern and magnitude of genealogical diversity, as revealed by mitochondrial DNA (mtDNA) lineages. The relative importance of the different forces on a regional biota must be evaluated along with a good understanding of geological and climatological history. The peninsula of Baja California of north‐western Mexico is one area where both geology and climate have affected the historical biogeography of the regional biota. Molecular studies based on the genealogical relationships among mtDNA lineages have contributed greatly towards elucidating the historical biogeography of Baja California. Perhaps most noticeably, numerous concordant breaks in mtDNA genealogies half‐way along the peninsula suggest a vicariant history in which the mid‐peninsula was temporarily submerged. This vicariant explanation has recently been criticized, as no conclusive geological evidence exists for a continuous submergence of the mid‐peninsula. As an alternative, a scenario based on climatological factors has been suggested. Here we discuss the validity of the hypothesized mid‐peninsular vicariance event and the climate‐based alternative in explaining the concordant genealogical breaks. We argue that, despite the significant changes in climate brought about by the glacial cycles throughout the Quaternary, a vicariant history involving a mid‐peninsular seaway remains the most parsimonious explanation of the observed patterns in mtDNA genealogies.
Modelling the influence of change in fire regime on the local distribution of a Mediterranean pyrophytic plant species (Cistus salviifolius) at its northern range limit
Authors: Moretti Marco , Conedera Marco , Moresi Ruben , Guisan Antoine
Published: June 2006

Aims  To assess the potential distribution of an obligate seeder and active pyrophyte, Cistus salviifolius, a vulnerable species in the Swiss Red List; to derive scenarios by changing the fire return interval; and to discuss the results from a conservation perspective. A more general aim is to assess the impact of fire as a natural factor influencing the vegetation of the southern slopes of the Alps.

Location  Alps, southern Switzerland.

Methods  Presence–absence data to fit the model were obtained from the most recent field mapping of C. salviifolius. The quantitative environmental predictors used in this study include topographic, climatic and disturbance (fire) predictors. Models were fitted by logistic regression and evaluated by jackknife and bootstrap approaches. Changes in fire regime were simulated by increasing the time‐return interval of fire (simulating longer periods without fire). Two scenarios were considered: no fire in the past 15 years; or in the past 35 years.

Results  Rock cover, slope, topographic position, potential evapotranspiration and time elapsed since the last fire were selected in the final model. The Nagelkerke R2 of the model for C. salviifolius was 0.57 and the Jackknife area under the curve evaluation was 0.89. The bootstrap evaluation revealed model robustness. By increasing the return interval of fire by either up to 15 years, or 35 years, the modelled C. salviifolius population declined by 30–40%, respectively.

Main conclusions  Although fire plays a significant role, topography and rock cover appear to be the most important predictors, suggesting that the distribution of C. salviifolius in the southern Swiss Alps is closely related to the availability of supposedly competition‐free sites, such as emerging bedrock, ridge locations or steep slopes. Fire is more likely to play a secondary role in allowing C. salviifolius to extend its occurrence temporarily, by increasing germination rates and reducing the competition from surrounding vegetation. To maintain a viable dormant seed bank for C. salviifolius, conservation managers should consider carrying out vegetation clearing and managing wild fire propagation to reduce competition and ensure sufficient recruitment for this species.
Site‐specific mutation of the interferon sensitivity‐determining region (ISDR) modulates hepatitis C virus replication
Authors: Kohashi T. , Maekawa S. , Sakamoto N. , Kurosaki M. , Watanabe H. , Tanabe Y. , Chen C.‐H. , Kanazawa N. , Nakagawa M. , Kakinuma S. , Yamashiro T. , Itsui Y. , Koyama T. , Enomoto N. , Watanabe M.
Published: June 2006

Summary. The number of amino acid substitutions in the interferon sensitivity‐determining region (ISDR) in the nonstructural 5A (NS5A) gene of hepatitis C virus (HCV) is closely associated with the interferon (IFN) response and viral load. Several HCV replicon‐based studies have reported that ISDR sequences had an influence on viral replicationin vitro. However, it is unclear as to how different ISDR sequences affect HCV replication. Various clinically observed ISDR sequences were introduced into HCV replicons and their contribution to viral replication was investigated using a colony formation assay and/or a transient replication assay. A mapping study of the ISDR was performed to identify the amino acid positions that critically affect replication. While no colonies were formed in the colony formation assay using HCV replicons with few mutations (0, 1 and 3) in the ISDR, numerous colonies (>200) appeared when using constructs with six mutations. Introduction of various distinct ISDR sequences with multiple mutations resulted in replication enhancement in transient assays. A mapping study identified several specific sites in the ISDR that critically affected replication, including codon 2209 which, in patients, was closely associated with a strong response to IFN. ISDR sequences associated with a clinical IFN response and viral load modulated the replication of HCV replicons, suggesting the importance of the ISDR sequence in HCV infection.
Molecular and serological characterization of hepatitis B virus in deferred Ghanaian blood donors with and without elevated alanine aminotransferase
Authors: Candotti D. , Opare‐Sem O. , Rezvan H. , Sarkodie F. , Allain J.‐P.
Published: June 2006

Summary.  Candidate blood donors in Ghana are frequent carriers of hepatitis B virus (HBV). A comparative study of 117 donor samples including 46 with alanine aminotransferase (ALT) ≥ 60 IU/L and 71 with ≤40 IU/L level was undertaken. S and the basic core promoter‐precore regions (BCP/PC) sequencing was used to identify genotypes and variants relevant to HBV natural history, respectively. Age, viral load, HBe status were correlated with molecular data. HBV genotype E (87%) was dominant with little genotypes A (10%) and D (3%). Comparing individuals with or without liver disease, an association between liver disease and older age (P = 0.004) and higher viral load (P = 0.002) whether as a whole population or only genotype E was found. Compared with a commercial assay, BCP/PC sequencing had lower sensitivity to detect mixtures of wild‐type and variant viruses but detected BCP deletions. BCP 1762/1764 variants were positively correlated with older age (P < 0.0001) and elevated ALT levels (P = 0.01). PC 1896 stop codon was marginally correlated with viral load (P = 0.09). HBV genotype E infection natural history appears different from genotypes B and C prevalent in Asia. Donors with liver disease being older, with higher viral load and higher BCP variant proportion may be at higher risk of cirrhosis and hepatocellular carcinoma
Comparison of radiographic landmarks and the echocardiographic SVC/RA junction in the positioning of long‐term central venous catheters
Authors: Hsu J.‐H. , Wang C.‐K. , Chu K.‐S. , Cheng K.‐I. , Chuang H.‐Y. , Jaw T.‐S. , Wu J.‐R.
Published: June 2006

Background:  When implanting a permanent central venous catheter, the usual aim is to place the tip at the superior vena cava/right atrial (SVC/RA) junction. However, data validating radiographic landmarks of the SVC/RA junction are limited. This investigation was undertaken to compare the radiographic landmarks with the SVC/RA junction as determined by transesophageal echocardiography (TEE).

Methods:  In 20 adult oncologic patients undergoing implantation of a permanent subcutaneous central venous catheter, the catheter tip was placed in the SVC/RA junction under TEE guidance. The position of the catheter tip on chest X‐ray, which represented the echocardiographic SVC/RA junction, was then compared with a standard radiographic landmark of the SVC/RA junction and with thoracic vertebral levels.

Results:  In all but two patients radiographic SVC/RA junctions were identified. The echocardiographic SVC/RA junction ranged from 0.6 cm above to 2.8 cm below the radiographic SVC/RA junction. There was a significant difference between the distance from the carina to the radiographic SVC/RA junction and the distance from the carina to the echocardiographic SVC/RA junction. The thoracic vertebral body correlating with the echocardiographic SVC/RA junction ranged from the sixth to the ninth level.

Conclusion:  Both the radiographic SVC/RA junction and the thoracic vertebral bodies are not reliable landmarks for the SVC/RA junction defined by TEE. Physicians should be aware that using the radiographic SVC/RA junction to confirm proper positioning of permanent central venous catheters risks placing the catheter tip in the upper SVC, with subsequent potential long‐term complications. More reliable radiographic landmarks for the SVC/RA junction should be investigated.
Enoximone in cardiac arrest caused by propranolol: two case reports
Authors: Sandroni C. , Cavallaro F. , Caricato A. , Scapigliati A. , Fenici P. , Antonelli M.
Published: June 2006

We report two clinical cases of cardiac arrest, the former due to an adverse effect of intravenous (i.v.) propranolol in a patient with systemic sclerosis, the latter from a propranolol suicidal overdose. In both cases, conventional advanced life support (ALS) was ineffective but both patients eventually responded to the administration of enoximone, a phosphodiesterase III (PDE III) inhibitor. After the arrest, both patients regained consciousness and were discharged home. The chronotropic and inotropic effects of PDE III inhibitors are due to inhibition of intracellular PDEIII and are therefore unaffected by beta‐blockers. These cases suggest that PDEIII inhibitors may be useful in restoring spontaneous circulation in cardiac arrest associated with beta‐blocker administration when standard ALS is ineffective.
Cerebral state index response to incision: a clinical study in day‐surgical patients
Authors: Anderson R. E. , Jakobsson J. G.
Published: June 2006

Background:  Inadequate anaesthesia, with somatic/autonomic response or awareness, is often revealed at intubation and surgical incision. Anaesthetic depth monitors should be able to prevent this risk. This explorative study examined the ability of the cerebral state monitor to predict autonomic/somatic responses to incision.

Methods:  Forty‐two ASA I–II day‐surgical patients [19 men and 23 females; mean age 52 (29–79) years, mean weight 77 (50–118) kg] were induced clinically with fentanyl/propofol with sevoflurane after placement of the laryngeal mask airway. The cerebral state index (CSI™) was blindly recorded 4 min prior to and 4 min after incision.

Results:  During the 4 min prior to incision, the mean CSI™ was 45 (16–62) and increased by 9 (–13–40) when the mean value for the first 4 min after incision was subtracted from the value prior to incision, corresponding to a relative change of 21% (–21–118). The change in CSI™ did not show any consistent relation to the value before incision. Five patients showed minor movements after incision and six patients had > 25% increase in blood pressure. Neither CSI™ nor the change in index differed between patients who did or did not respond somatically or autonomically to incision. The last CSI™ value just prior to incision was 44 for non‐responders and 40 and 42 for somatic and autonomic responders, respectively.

Conclusion:  The CSI™ in the majority of patients was within acceptable ranges during clinically adjusted anaesthesia prior to incision but seems not to be able to reliably predict an autonomic or somatic response to incision.
Portable ultrasound in pre‐hospital emergencies: a feasibility study
Authors: Busch M.
Published: June 2006

Background:  Ultrasound plays a central role in the evaluation of both trauma and medical emergencies. The development of portable sonography devices could extent its application into the pre‐hospital arena. The aim of our study was to evaluate feasibility of pre‐hospital ultrasound in the Norwegian Air Rescue setting.

Material and methods:  During a 3‐month period, we conducted a prospective study using sonography in pre‐hospital patient management. All examinations were carried out by the same ultrasound‐certified physician using a Primedic™ Handyscan in a standardized focused protocol for abdominal and lung sonography and a subcostal 2‐chamber long axis view. Inclusion criteria were abdominal/thoracic and obstetric trauma, circulatory/respiratory compromise, pulseless electric activity (PEA) in cardiac arrest, acute abdomen and monitoring during transport. Allowed examination time was restricted to 3 min on the scene. The patient’s gender, age, symptoms, trauma mechanism, quality of visualization and diagnose made were recorded. Pre‐hospital results were compared with in‐hospital findings.

Results:  Thirty‐eight patients were entered into the study. Three patients had to be excluded due to technical difficulties. Nineteen medical, 15 traumas and 1 obstetric patient were included. Good visualization was obtained in 74% (n= 26), moderate in 26% (n= 9). Median examination time was 2.5 min (range 1–3 min). Nine patients (26%) showed positive sonography findings. Sensitivity was 90%, specificity 96%. Diagnostic usefulness was high in undetermined cardiac arrest and hypotension and massive hematoperitoneum.

Conclusion:  Pre‐hospital ultrasound when applied by an proficient examiner using a goal‐directed, time sensitive protocol is feasible, does not delay patient management and provides diagnostic and therapeutic benefit. Further studies are warranted to identify the exact indications and role of pre‐hospital sonography.
Management of near fatal blunt laryngeal trauma
Authors: Irwin E. , Lonnée H.
Published: June 2006

Blunt laryngeal trauma is uncommon, difficult to diagnose and recommended assessment and management guidelines differ. Mortality can be as high as 40%. Initial symptoms might mask the seriousness of the injury and a history of trauma is important. This report describes a case which illustrates many of the difficulties encountered. A high index of suspicion is needed, and all patients with a suspected blunt laryngeal injury, even with minor symptoms, should be taken seriously and considered for early precautionary airway intervention.
Beneficial outcome after prostaglandin‐induced post‐partum cardiac arrest using levosimendan and extracorporeal membrane oxygenation
Authors: Krumnikl J. J. , Toller W. G. , Prenner G. , Metzler H.
Published: June 2006

Background:  Administration of high doses of prostaglandins is a frequently performed and effective method for the treatment of atonic uterine haemorrhage in order to increase uterine muscle tone. Rarely, however, these drugs may cause life‐threatening complications including bronchospasm, acute pulmonary oedema and myocardial infarction caused by coronary spasms.

Methods:  We discuss the management of a patient suffering post‐partum atonic uterine bleeding, catecholamine‐resistant cardiac arrest and fulminant pulmonary failure due to deleterious side‐effects of treatment with prostaglandins.

Results:  During therapy resistant cardiopulmonary resuscitation, the addition of levosimendan to standard medications resulted in a prompt stabilization of haemodynamics. Subsequent treatment of pulmonary failure was successfully managed with ECMO.

Conclusion:  Although levosimendan is not approved for pharmacological treatment of cardiopulmonary arrest, the beneficial effects in this patient suggest an important role of calcium sensitization and vasodilation during prostaglandin‐induced cardiac arrest.
Being a young and inexperienced trainee anesthetist: a phenomenological study on tough working conditions
Authors: Larsson J. , Rosenqvist U. , Holmström I.
Published: June 2006

Background:  Physicians at the beginning of their specialist education have been reported to be especially exposed to stress and difficult working conditions. Considerable worry has also been caused by reports about anaesthetists dying at a younger age than other specialists as well as by reports about higher than average suicide rates among anaesthetists. Maybe as a consequence, many young doctors are reluctant to choose anaesthesiology as their future specialty. The aim of this study was to investigate what difficulties trainee anaesthetists experience at work.

Methods:  Nineteen trainee anaesthetists in six Swedish hospitals were interviewed. Phenomenological analysis of the interview text was performed.

Results:  All trainees had experienced considerable, sometimes extreme demands at work. Most of them often felt insufficient and inadequate and had problems with the professional role. Support from consultants was sometimes lacking. Some trainees expressed deep feelings of loneliness and helplessness in difficult clinical situations.

Conclusions:  This study shows that trainee anaesthetists have to live up to high work demands, often with very little support. Because too much stress is an obstacle to professional learning, such working conditions are a hindrance to good specialist education. The first measure to be taken should be to ensure that all trainee anaesthetists always have easy access to senior cover.
Efficacy of multimodal optimization of mobilization and nutrition in patients undergoing hip replacement: a randomized clinical trial
Authors: Petersen M. K. , Madsen C. , Andersen N. T. , Søballe K.
Published: June 2006

Background:  The aim of this trial was to assess the effects of optimization of mobilization and nutrition on patients undergoing primary total hip replacement (THR).

Methods:  Seventy‐nine patients undergoing elective primary THR were recruited prospectively. After randomization, one group received optimized pre‐operative information and enforced mobilization and nutrition, another group received conventional peri‐operative care. Epidural anaesthesia and post‐operative epidural analgesia with local anaesthetics and opioids were used in all cases. Outcome related to length of stay, complications, pain, mobilization, energy intake, and physical activities of daily living (PADL).

Results:  Although mobilization and nutrition were highly significantly increased in the intervention group, the reduction in length of stay was moderate (7.0 vs. 8.0 days P= 0.019). We found no differences between groups in relation to complications or pain. In the intervention group, the median day of independence in PADL was the third post‐operative day (2 : 6 day) and the fourth post‐operative day (2 : 7 day) in the control group. The difference was not significant.

Conclusion:  Compared with conventional care, optimal and aggressive nutrition and mobilization resulted in a very moderate reduction in length of stay. There were no differences regarding pain, complications or time until independence in PADL.