bluuebunny/crossref_metadata_2025 huggingface dataset:
A longitudinal evaluation of medical student knowledge, skills and attitudes to alcohol and drugs
Authors: Cape Gavin , Hannah Annette , Sellman Doug
Published: May 2006

Aim  To examine the knowledge, skills and attitudes of medical students to alcohol and drugs as training progresses.

Design  A longitudinal, prospective, cohort‐based design.

Setting  The four schools of medicine in New Zealand.

Participants  All second‐year medical students (first year of pre‐clinical medical health sciences) in New Zealand were administered a questionnaire which was repeated in the fourth (first year of significant clinical exposure) and then sixth years (final year). A response rate of 98% in the second year, 75% in the fourth year and 34% in the sixth year, with a total of 637 respondents (47.8% male) and an overall response rate of 68%.

Questionnaire  The questionnaire consisted of 43 questions assessing knowledge and skills—a mixture of true/false and scenario stem‐based multiple‐choice questions and 25 attitudinal questions scored on a Likert scale. Demographic questions included first language, ethnicity and personal consumption of alcohol and tobacco.

Findings  The competence (knowledge plus skills) correct scores increased from 23.4% at the second year to 53.6% at the fourth year to 71.8% at the sixth year, being better in those students who drank alcohol and whose first language was English (P < 0.002). As training progressed the student’s perceptions of their role adequacy regarding the effectiveness of the management of illicit drug users diminished. For example, at second year 21% and at sixth year 51% of students felt least effective in helping patients to reduce illicit drug use. At the sixth year, 15% of sixthyear students regarded the self‐prescription of psychoactive drugs as responsible practice.

Conclusion  Education on alcohol and drugs for students remains a crucial but underprovided part of the undergraduate medical curriculum. This research demonstrated that while positive teaching outcomes were apparent, further changes to medical student curricula need to be considered to address specific knowledge deficits and to increase the therapeutic commitment and professional safety of medical students to alcohol and drugs.
Switch patterns before and after patent expiry of omeprazole: a case study in The Netherlands
Authors: KLOK R. M. , BOERSMA C. , OOSTERHUIS I. , VISSER S. T. , DE JONG‐VAN DEN BERG L. T. W. , POSTMA M. J.
Published: May 2006

Background

An increase of therapeutic substitution after patent expiry might have a negative effect on cost‐savings generated with newly introduced generic drugs. To evaluate influences of patent expiry on therapeutic substitution, switch behaviour before and after patent expiry was investigated.

Aim

To describe proton pump inhibitor use and investigate substitution patterns from omeprazole before and after patent expiry.

Methods

Data were obtained from the InterAction DataBase. Proportional proton‐pump inhibitor use was identified per quarter during the study period 2000–2003. For the second part two cohorts – one before and one after patent expiry – were defined. The number of switchers was quarterly identified during 2‐year follow‐up period. For statistical analyses the chi‐square test and hazard ratio were used.

Results

In proportional use, a downward trend for omeprazole was found. After patent expiry, significantly more patients switched to other proton pump inhibitors (P < 0.001). The hazard ratio of 0.62 (95% CI: 0.57–0.69), indicates that for every six patients switching before patent expiry, 10 patients switch after patent expiry.

Conclusion

After patent expiry more patients switch to another proton pump inhibitor. In light of the total savings achieved with generic omeprazole, the importance of this negative impact on total cost‐savings on proton pump inhibitors is unclear.
Personal view: current role of artificial liver support devices
Authors: O'GRADY J.
Published: May 2006

Enthusiasm for liver support devices, particularly cell‐based biological systems and albumin dialysis, increased over the last decade and there has been considerable clinical activity both within and without the construct of clinical trials. Most data have been generated on patients with acute liver failure or in patients with decompensation of chronic liver disease, often referred to as acute‐on‐chronic liver failure.

In acute liver failure liver, liver support devices are more realistically being used as a ‘bridge’ to liver transplantation rather than to transplant‐free survival. In acute‐on‐chronic liver failure the clinical objective of attaining clinical stability with treatment appears more achievable.

The so‐called bioartificial liver device, based on porcine hepatocytes, is the most extensively evaluated biological device. A sizeable clinical trial failed to demonstrate efficacy, but secondary analyses suggest it would be unwise to assume futility had been established with this device.

Molecular adsorbent recirculating system leads the way in the non‐biological category in terms of the number of patients treated, but data from large clinical trials are not yet available.

One of the strongest conclusions of this review is that the amount of high‐quality data available on liver support devices dramatically understates the effort and money that have been expended in their assessment. It is very clear that randomized controlled trials are mandatory to establish clinical efficacy, but it is less clear how the ideal trial should be constructed.
Effect of frequent dosing of an oral proton pump inhibitor on intragastric pH
Authors: PAIS S. A. , NATHWANI R. A. , DHAR V. , NOWAIN A. , LAINE L.
Published: May 2006

Background

Treatment with a continuous i.v. proton pump inhibitor is presumed to promote clot formation and stability by sustaining intragastric pH ≥ 6.

Aim

We postulated that very frequent oral dosing of proton pump inhibitors should simulate i.v. infusion and achieve similar pH control.

Methods

Twenty healthy volunteers were stratified by Helicobacter pylori status (10 positive; 10 negative) and had determination of CYP2C19 status. After an overnight fast, an intragastric pH probe was placed. Subjects received 120 mg of lansoprazole at 8 am and 30 mg every 3 h until 8 pm. Intragastric pH was measured over 24 h, and lansoprazole plasma concentrations were determined at five time points.

Results

Intragastric pH was ≥6 for 41% (95% CI: 30–53%) of the 15‐h period from 8 am–11 pm and 46% (95% CI: 35–56%) of the 24‐h period (8–8 am). The mean proportion of patients with pH ≥6 was not significantly different in H. pylori‐positive vs. negative patients. Only 25% of subjects sustained pH ≥6 for at least 60% of the 15‐h period, and 35% had a sustained pH ≥6 for at least 60% of the 24‐h period.

Conclusions

A dose of 120 mg of oral lansoprazole followed by standard 30 mg doses of lansoprazole every 3 h did not reliably sustain pH at the desired level of 6.
Hyperpyrexia and prolonged postoperative disorientation following methylene blue infusion during parathyroidectomy
Authors: Mathew S. , Linhartova L. , Raghuraman G.
Published: May 2006

A 65‐year‐old man underwent parathyroidectomy for hyperparathyroidism secondary to renal failure. Intra‐operatively he received methylene blue infusion (7.5 mg.kg−1, a total of 650 mg in 500 ml 0.9% sodium chloride) for visualisation of parathyroid glands. At the end of surgery, following extubation he developed agitation, intense shivering and hyperpyrexia, and his level of consciousness decreased to a Glasgow Coma score of 7. The differential diagnoses included methylene blue toxicity or malignant hyperpyrexia. His lungs were ventilated, and intravenous dantrolene was administered to control hyperpyrexia. Haemodialysis was started to remove the methylene blue dye. We review the literature on the pharmacological actions of methylene blue, and discuss the differential diagnosis and management of this patient.
Endobronchial tubes – a case for re‐evaluation
Authors: Conacher I. D. , Velasquez H. , Morrice D. J.
Published: May 2006

An endobronchial tube (Macintosh‐Leatherdale) was used to secure the airway for a tracheal resection and end‐to‐end anastomosis. This lung separation device enabled insertion of both a fibreoptic bronchoscope and a tube exchange catheter. These were required after the trachea was transected and re‐anastomosis proved surgically difficult. The airway exchange catheter allowed for jet ventilation and later a tube change when an emergency occurred. Options and management issues for tracheal surgery and lung separators are discussed. A case is made for a re‐evaluation of endobronchial tubes both as a useful conduit for modern airway instruments and as an alternative to small double‐lumen tubes for the increasing population of obese patients weighing > 100 kg, requiring thoracic surgery.
Epidural anaesthesia as a complication of attempted brachial plexus blockade using the posterior approach
Authors: Gomez R. S. , Mendes T. C. B. S.
Published: May 2006

We report a case of accidental epidural anaesthesia as a complication of attempted brachial plexus blockade using a posterior approach in a 31‐year‐old man scheduled to undergo elective shoulder surgery. The block was inserted with the patient in the lateral position before induction of general anaesthesia. On emergence from anaesthesia, the patient could breathe but could not move his arms. He had no pain sensation from the fifth cervical dermatome to the third thoracic dermatome bilaterally; this resolved 8 h after surgery and he was discharged well 2 days later. Although proponents of the posterior approach to the brachial plexus claim that its use is associated with a lower incidence of significant complications, this case proves that the technique is not devoid of potentially serious complications.
Major colorectal surgery in a patient with cold agglutinin disease
Authors: Young S. , Haldane G.
Published: May 2006

We present the case of a 62‐year‐old man with severe cold agglutinin disease who underwent major colorectal surgery. Cold agglutinin disease is a condition in which auto‐antibodies, usually immunoglobulin M, cause red blood cell agglutination at decreased body temperature. Haemolysis may result. Agglutination results in impaired perfusion, resulting in symptomatic Raynaud's phenomenon and acrocyanosis. Haemolysis can result in anaemia and thrombotic events caused by microvascular occlusion, in addition to haemoglobinuria and renal failure. Peri‐operative hypothermia is common in all patients and may be associated with significant morbidity, but is potentially catastrophic in a patient suffering from cold agglutinin disease.
Use of the fibreoptic intubating LMA‐CTrach™ in two patients with difficult airways
Authors: Goldman A. J. , Rosenblatt W. H.
Published: May 2006

We report two patients with difficult airways who underwent tracheal intubation using the new fibreoptic intubating Laryngeal Mask Airway CTrach™. The imaging technology of the LMA‐CTrach was decisive in the management of these two patients. The first patient had lingual tonsillar hyperplasia, and an omega‐shaped retroflexed epiglottis. The second patient had a C2‐occipital fusion and was completely unable to extend her head. Given the anatomical difficulties encountered, it was likely that intubation would have been difficult or impossible through the LMA‐Fastrach™. The aim of this report is to describe the successful use of this new intubating laryngeal mask airway in these two challenging patients.
Sensitization to different pollens and allergic disease in 4‐year‐old Swedish children
Authors: Ghunaim N. , Wickman M. , Almqvist C. , Söderström L. , Ahlstedt S. , Van Hage M.
Published: May 2006

Background
Although the relationship between sensitization to different inhalant allergens in adolescents and adults has been intensively studied, information concerning sensitization in children is scarce in particular to pollens.

Objectives
In 4‐year‐old children to elucidate the pollen immunoglobulin (IgE) antibody profile (birch only, timothy only and combinations of three pollens (birch, timothy or mugwort) and to relate the results to other inhalant and food allergens, as well as the presence of allergic diseases.

Methods
A total of 2551 4‐year‐old children belonging to a prospective birth cohort, which has been followed longitudinally (BAMSE), were investigated with respect to IgE antibodies to pollen and other inhalant and food allergens, and expression of allergic disease, based on questionnaire data.

Results
Eleven percent (n=285) of the children were sensitized to pollen. Birch was the dominating cause of pollen sensitization (birch sensitization only, n=133); followed by timothy grass pollen (n=56) and a combination of two (n=64) or three (n=30) pollens. A remarkably high proportion of the children sensitized only to birch was also sensitized to other inhalant allergens. This was not seen for children sensitized only to timothy. The highest frequencies of IgE reactivity to food were found in the group of children sensitized to the combination of birch, timothy and mugwort pollen. Children sensitized to timothy only, exhibited symptoms of allergic disease significantly less frequently compared with children sensitized to birch only. Sensitization to birch pollen was found to be closely associated with rhinitis and eczema compared with asthma. The highest frequency of asthma and/or rhinitis and/or eczema was reported in children sensitized to at least two pollens.

Conclusion
Our results demonstrate that birch is the dominating source of pollen sensitization at the age of four in Sweden. This might associate with the pattern of sensitization to other inhalant and food allergens as well as influence on the expression of allergic disease in this particular age group.
The effect of allergic rhinitis on adenosine concentration in exhaled breath condensate
Authors: Vass G. , Huszár É. , Augusztinovicz M. , Baktai G. , Barát E. , Herjavecz I. , Horváth I.
Published: May 2006

BackgroundPatients with allergic rhinitis (AR) frequently develop asthma. This initiating inflammation in the lower airways may result in increased levels of inflammatory mediators such as adenosine in the exhaled breath.

ObjectiveWe compared adenosine levels in exhaled breath condensate (EBC) and both exhaled and nasal nitric oxide (NO) levels of AR patients and healthy control subjects. We also tested whether inhalation through inflamed nasal cavity during EBC sampling influences adenosine concentrations in exhaled air.

MethodsExhaled and nasal NO levels were measured and EBC samples (at oral inhalation) were collected from 27 patients and 15 healthy controls. EBC collection was repeated after 15 min with subjects inhaling through their nose. Adenosine was measured by HPLC and NO was determined by chemiluminescence.

ResultsThe concentration of EBC adenosine was higher in patients with AR than in healthy controls (12.4±1.3 nmvs. 6.5±0.7 nm,P=0.0019) and this was accompanied by an increase in the concentration of exhaled NO (10.2±1.3 ppb vs. 5.3±0.5 ppb;P=0.0099, respectively). No difference in nasal NO was detected. EBC adenosine concentration showed a significant positive correlation with the level of exhaled NO. In contrast to healthy control subjects, patients with rhinitis had higher levels of exhaled adenosine when inhaling via the nose instead of the mouth (17.7±2.8 nm,P=0.007).

ConclusionWhen compared with healthy subjects, patients with AR exhibit an increased concentration of exhaled adenosine and a related increase in exhaled NO concentration. EBC adenosine is further increased when rhinitis patients inhale through their nose than via their mouth. Our data suggest that non‐asthmatic patients with rhinitis may have subclinical inflammation in their lower airways.
Leaf endophytes affect mycorrhizal status and growth of co‐infected and neighbouring plants
Authors: OMACINI M. , EGGERS T. , BONKOWSKI M. , GANGE A. C. , JONES T. H.
Published: May 2006

Fungal leaf endophytes and arbuscular mycorrhizal (AM) fungi are common constituents of natural grasslands. The simultaneous presence of these two grass plant symbionts is highly probable.

We describe the results of a glasshouse experiment investigating the outcome of dual infection of a cool‐season grass species,Lolium multiflorum, by the fungal endophyteNeotyphodium occultansand three species ofGlomusAM fungi.

Mycorrhizal colonization was investigated on monocultures of plants with or without leaf endophytes, and on mixtures of endophyte‐infected and uninfected plants. In both scenarios, endophyte‐infected plants had lower levels of mycorrhizal colonization, but in the endophyte mixtures the presence of endophyte‐infected plants caused an increase in AM colonization in non‐endophyte‐infected conspecific neighbours.

Host‐plant biomass, nutrient (nitrogen and phosphorus) accumulation, and competitive ability were increased by the presence of endophytes. AM fungi did not improve host performance or nutrient content (concentration or accumulation) in the presence or absence of the endophyte.

Interactions between host plants and AM fungi are mediated by fungal endophyte infection. The implications of such modified interactions for ecosystem dynamics and functioning are considered.
Olfactory information saves venom during prey‐capture of the hunting spider Cupiennius salei (Araneae: Ctenidae)
Authors: HOSTETTLER S. , NENTWIG W.
Published: May 2006

The Neotropical spider Cupiennius salei Keyserling (Ctenidae) selects prey in a manner consistent with the amount of venom available in its venom glands. It distinguishes the venom sensitivity of different prey species, and uses its venom economically (according to the venom‐optimization hypothesis).

A prey‐choice experiment was performed to test whether spiders use olfactory cues to detect prey and select prey items that are appropriate for their amount of available venom.

The spider could choose between two similar prey dummies made of agar. We added the odour of two prey species, either by adding minced insects to an agar block or by offering it on filter paper which had previously been exposed to the living prey. Cupiennius salei spiders had either full or emptied venom glands.

Two insects of distinctive venom sensitivity, but high acceptance, were tested: a sensitive cricket and a less sensitive cockroach.

Using video surveillance, we found an attraction effect of prey odour in the prey‐capture behaviour of C. salei. Spiders preferred agar pieces with minced insects or insect odour on filter paper over non‐smelling items. Reaction frequency and attack rates were equal for spiders with full venom glands if they had to choose between cricket and cockroach odour. When the venom glands were empty, however, C. salei significantly preferred the venom‐sensitive cricket over the venom‐insensitive cockroach.

We showed for the first time that C. salei uses its olfactory sense to detect prey items, and distinguishes between prey species with low and high sensitivity to spider venom. This study supports the venom‐optimization hypothesis.
How a mega‐grazer copes with the dry season: food and nutrient intake rates by white rhinoceros in the wild
Authors: SHRADER A. M. , OWEN‐SMITH N. , OGUTU J. O.
Published: May 2006

Few studies have investigated how free‐ranging wild herbivores adjust their food intake rate and nutrient gains during the dry season. Our study focused on the largest extant grazer, the white rhinoceros (Ceratotherium simumBurchell 1817). Field measurements were made on changes in bite mass, bite rate and nutrient concentrations of food eaten during the dry season.

As the dry season progressed, the quality and availability of food resources declined. During this time white rhinos foraged mainly in high‐quality short and woodland grasslands. Late in the dry season they also used flushes of green grass in previously burnt Themeda grasslands.

Bite mass increased linearly with increasing sward height, while bite rate declined. Intake rate was determined primarily by bite mass and thus tended to increase linearly with sward height. Maximum bite mass and intake rate was obtained in swards >20 cm.

White rhinos did not compensate for seasonal declines in food quality by adjusting their food intake rate or diet breadth. We suggest that white rhinos mobilize fat reserves to help meet their nutritional needs during the dry season.
Demystifying the West, Brown & Enquist model of the allometry of metabolism
Authors: ETIENNE RAMPAL S. , APOL M. EMILE F. , OLFF HAN
Published: May 2006

The allometry of metabolic rate has long been one of the key relationships in ecology. While its existence is generally agreed on, the exact value of the scaling exponent, and the key mechanisms that determine its value, are still hotly debated.

The network model of West, Brown & Enquist (Science 276, 122–126, 1997) predicts a value of 3/4 but, although appealing, this model has not been generally accepted.

Here we reconstruct the model and derive the exponent in a clearer and much more straightforward way that requires weaker assumptions than the original model. Specifically, self‐similarity of the network is not required. Our formulation can even be used if one or several assumptions of West et al. (1997) are considered invalid.

Moreover, we provide a formula for the proportionality constant (i.e. the intercept of the allometric scaling relation) that shows explicitly where factors as temperature and stoichiometry affect metabolism.
Climate–growth relationships of tropical tree species in West Africa and their potential for climate reconstruction
Authors: SCHÖNGART JOCHEN , ORTHMANN BETTINA , HENNENBERG KLAUS JOSEF , POREMBSKI STEFAN , WORBES MARTIN
Published: May 2006

Most tropical regions are facing historical difficulties of generating biologically reconstructed long‐term climate records. Dendrochronology (tree‐ring studies) is a powerful tool to develop high‐resolution and exactly dated proxies for climate reconstruction. Owing to the seasonal variation in rainfall we expected the formation of annual tree rings in the wood of tropical West African tree species. In the central‐western part of Benin (upper Ouémé catchment, UOC) and in northeastern Ivory Coast (Comoé National Park, CNP) we investigated the relationship between climate (precipitation, sea surface temperature (SST)) and tree rings and show their potential for climate reconstruction. Wood samples of almost 200 trees belonging to six species in the UOC and CNP served to develop climate‐sensitive ring‐width chronologies using standard dendrochronological techniques. The relationship between local precipitation, monthly SST anomalies in the Gulf of Guinea, El Niño‐ Southern Oscillation (ENSO) and ring‐width indices was performed by simple regression analyses, two sample tests and cross‐spectral analysis. A low‐pass filter was used to highlight the decadal variability in rainfall of the UOC site. All tree species showed significant relationships with annual precipitation proving the existence of annual tree rings. ENSO signals could not be detected in the ring‐width patterns. For legume tree species at the UOC site significant relationships could be found between SST anomalies in the Gulf of Guinea indicating correlations at periods of 5.1–4.1 and 2.3 years. Our findings accurately show the relationship between tree growth, local precipitation and SST anomalies in the Gulf of Guinea possibly associated with worldwide SST patterns. A master chronology enabled the reconstruction of the annual precipitation in the UOC to the year 1840. Time series analysis suggest increasing arid conditions during the last 160 years which may have large impacts on the hydrological cycles and consequently on the ecosystem dynamics and the development of socio‐economic cultures and sectors in the Guinea‐Congolian/Sudanian region.
Ecosystem recovery: heathland response to a reduction in nitrogen deposition
Authors: POWER SALLY A. , GREEN EMMA R. , BARKER CHRIS G. , BELL J. NIGEL B. , ASHMORE MIKE R.
Published: May 2006

Atmospheric deposition of nitrogen is responsible for widespread changes in the structure and function of sensitive seminatural ecosystems. The proposed reduction in emissions of nitrogenous pollutants in Europe under the Gothenburg Protocol raises the question of whether affected ecosystems have the potential to recover to their previous condition and, if so, over what timescale. Since 1998, we have monitored the response of a lowland heathland in southern England following the cessation of a long‐term nitrogen addition experiment, and subsequent management, assessing changes in vegetation growth and chemistry, soil chemistry and the soil microbial community. Persistent effects of earlier nutrient loading on Calluna growth and phenology, and on the abundance of lichens, were apparent up to 8 years after nitrogen additions ceased, indicating the potential for long‐term effects of modest nutrient loading (up to 15.4 kg N ha−1 yr−1, over 7 years) on heathland ecosystems. The size and activity of the soil microbial community was elevated in former N‐treated plots, 6–8 years after additions ceased, suggesting a prolonged effect on the rate of nutrient cycling. Although habitat management in 1998 reduced nitrogen stores in plant biomass, effects on belowground nitrogen stores were small. Although some parameters (e.g. soil pH) recover pretreatment levels relatively rapidly, others (e.g. vegetation cover and microbial activity) respond much more slowly, indicating that the ecological effects of even small increases in nitrogen deposition will persist for many years after deposition inputs are reduced. Indeed, calculations suggest that the additional soil nitrogen storage associated with 7 years of experimental nitrogen inputs could sustain the observed effects on plant growth and phenology for several decades. Carry over effects on plant phenology and sensitivity to drought suggest that the persistence of vegetation responses to nitrogen deposition should be integrated into long‐term assessments of the impact of global climate change on sensitive ecosystems.
A matter of timing: changes in the first date of arrival and last date of departure of Australian migratory birds
Authors: BEAUMONT LINDA J. , McALLAN IAN A. W. , HUGHES LESLEY
Published: May 2006

Although there is substantial evidence that Northern Hemisphere species have responded to climatic change over the last few decades, there is little documented evidence that Southern Hemisphere species have responded in the same way. Here, we report that Australian migratory birds have undergone changes in the first arrival date (FAD) and last date of departure (LDD) of a similar magnitude as species from the Northern Hemisphere. We compiled data on arrival and departure of migratory birds in south‐east Australia since 1960 from the published literature, Bird Observer Reports, and personal observations from bird watchers. Data on the FAD for 24 species and the LDD for 12 species were analyzed. Sixteen species were short‐ to middle‐distance species arriving at their breeding grounds, seven were long‐distance migrants arriving at their nonbreeding grounds, and one was a middle‐distance migrant also arriving at its nonbreeding ground. For 12 species, we gathered data from more than one location, enabling us to assess the consistency of intraspecific trends at different locations. Regressions of climate variables against year show that across south‐east Australia average annual maximum and minimum temperatures have increased by 0.17°C and 0.13°C decade−1 since 1960, respectively. Over this period there has been an average advance in arrival of 3.5 days decade−1; 16 of the 45 time‐series (representing 12 of the 24 species studied) showed a significant trend toward earlier arrival, while only one time‐series showed a significant delay. Conversely, there has been an average delay in departure of 5.1 days decade−1; four of the 21 departure time‐series (four species) showed a significant trend toward later departure, while one species showed a significant trend toward earlier departure. However, differences emerge between the arrival and departure of short‐ to middle‐distance species visiting south‐east Australia to breed compared with long‐distance species that spend their nonbreeding period here. On average, short‐ to middle‐distance migrants have arrived at their breeding grounds 3.1 days decade−1 earlier and delayed departure by 8.1 days decade−1, thus extending the time spent in their breeding grounds by ∼11 days decade−1. The average advance in arrival at the nonbreeding grounds of long‐distance migrants is 6.8 days decade−1. These species, however, have also advanced departure by an average of 6.9 days decade−1. Hence, the length of stay has not changed but rather, the timing of events has advanced. The patterns of change in FAD and LDD of Australian migratory birds are of a similar magnitude to changes undergone by Northern Hemisphere species, and add further evidence that the modest warming experienced over the past few decades has already had significant biological impacts on a global scale.
Lipopolysaccharide induces CXCL2/macrophage inflammatory protein‐2 gene expression in enterocytes via NF‐κB activation: independence from endogenous TNF‐α and platelet‐activating factor
Authors: De Plaen Isabelle G. , Han Xin‐Bing , Liu Xueli , Hsueh Wei , Ghosh Sankar , May Michael J.
Published: May 2006

CXCL2 (macrophage inflammatory protein‐2 (MIP‐2)), a critical chemokine for neutrophils, has been shown to be produced in the rat intestine in response to platelet‐activating factor (PAF) and to mediate intestinal inflammation and injury. The intestinal epithelium, constantly exposed to bacterial products, is the first line of defence against micro‐organisms. It has been reported that enterocytes produce proinflammatory mediators, including tumour necrosis factor (TNF) and PAF, and we showed that lipopolysaccharide (LPS) and TNF activate nuclear factor (NF)‐κB in enterocytes. However, it remains elusive whether enterocytes release CXCL2 in response to LPS and TNF via a NF‐κB‐dependent pathway and whether this involves the endogenous production of TNF and PAF. In this study, we found that TNF and LPS markedly induced CXCL2 gene expression in IEC‐6 cells, TNF within 30 min, peaking at 45 min, while LPS more slowly, peaking after 2 hr. TNF‐ and LPS‐ induced CXCL2 gene expression and protein release were completely blocked by pyrrolidine dithiocarbamate (PDTC) and helenalin, two potent NF‐κB inhibitors. NEMO‐binding domain peptide, a specific inhibitor of inhibitor protein κB kinase (IKK) activation, a major upstream kinase mediating NF‐κB activation, significantly blocked CXCL2 gene expression and protein release induced by LPS. WEB2170 (PAF antagonist) and anti‐TNF antibodies had no effect on LPS‐induced CXCL2 expression. In conclusion, CXCL2 gene is expressed in enterocytes in response to both TNF and LPS. LPS‐induced CXCL2 expression is dependent on NF‐κB activation via the IKK pathway. The effect of LPS is independent of endogenous TNF and PAF.
Functional modulation of human intestinal epithelial cell responses by Bifidobacterium infantis and Lactobacillus salivarius
Authors: O'Hara Ann M. , O'Regan Padraig , Fanning Áine , O'Mahony Caitlin , MacSharry John , Lyons Anne , Bienenstock John , O'Mahony Liam , Shanahan Fergus
Published: May 2006

Intestinal epithelial cells (IECs) and dendritic cells (DCs) play a pivotal role in antigen sampling and the maintenance of gut homeostasis. However, the interaction of commensal bacteria with the intestinal surface remains incompletely understood. Here we investigated immune cell responses to commensal and pathogenic bacteria. HT‐29 human IECs were incubated with Bifidobacterium infantis 35624, Lactobacillus salivarius UCC118 or Salmonella typhimurium UK1 for varying times, or were pretreated with a probiotic for 2 hr prior to stimulation with S. typhimurium or flagellin. Gene arrays were used to examine inflammatory gene expression. Nuclear factor (NF)‐κB activation, interleukin (IL)‐8 secretion, pathogen adherence to IECs, and mucin‐3 (MUC3) and E‐cadherin gene expression were assayed by TransAM assay, enzyme‐linked immunosorbent assay (ELISA), fluorescence, and real‐time reverse transcriptase–polymerase chain reaction (RT‐PCR), respectively. IL‐10 and tumour necrosis factor (TNF)‐α secretion by bacteria‐treated peripheral blood‐derived DCs were measured using ELISA. S. typhimurium increased expression of 36 of the 847 immune‐related genes assayed, including NF‐κB and IL‐8. The commensal bacteria did not alter expression levels of any of the 847 genes. However, B. infantis and L. salivarius attenuated both IL‐8 secretion at baseline and S. typhimurium‐induced pro‐inflammatory responses. B. infantis also limited flagellin‐induced IL‐8 protein secretion. The commensal bacteria did not increase MUC3or E‐cadherin expression, or interfere with pathogen binding to HT‐29 cells, but they did stimulate IL‐10 and TNF‐α secretion by DCs. The data demonstrate that, although the intestinal epithelium is immunologically quiescent when it encounters B. infantis or L. salivarius, these commensal bacteria exert immunomodulatory effects on intestinal immune cells that mediate host responses to flagellin and enteric pathogens.
Natural killer cells prime the responsiveness of autologous CD4+ T cells to CTLA4‐Ig and interleukin‐10 mediated inhibition in an allogeneic dendritic cell–mixed lymphocyte reaction
Authors: Newland Ashley , Russ Graeme , Krishnan Ravi
Published: May 2006

Cytotoxic T‐lymphocyte antigen 4 immunoglobulin (CTLA4‐Ig) and interleukin (IL)‐10 are immunomodulatory molecules which target CD28 costimulation by acting either directly or indirectly on the CD80/86 receptors on dendritic cells (DCs). This study examined the effect of combined treatment with CTLA4‐Ig and IL‐10 on T‐cell responsiveness in a dendritic cell–mixed lymphocyte reaction (DC‐MLR). T cells derived from nylon wool enrichment (NWT cells) demonstrated 15% (P = 0·006) and 10% (P = 0·0015) inhibition of proliferation with suboptimal doses of IL‐10 (5 ng/ml) and CTLA4‐Ig (20 ng/ml), respectively. Combined treatment with both agents resulted in 38% inhibition (P = 0·004) of the MLR response compared with untreated controls. In contrast to NWT cells, which consisted of CD4+, CD8+ and CD56+ (NK) cells, purified CD4+ T cells were less responsive to immunomodulation by CTLA4‐Ig and IL‐10. Repletion of the CD4+ T cells with NK cells restored IL‐10 and CTLA4‐Ig mediated immunomodulation, suggesting a role for NK cells in the regulation of DC–T‐cell interactions. The specific effect of NK cells on DC activation was demonstrated by CD80 up‐regulation on DCs in the absence of T cells. However, in the absence of DCs, NK cells augmented the proliferation of autologous CD4+ T cells stimulated by anti‐CD3 monoclonal antibody (mAb), which was blocked by CTLA4‐Ig. It is proposed that, in the MLR, immunomodulation by suboptimal CTLA4‐Ig and IL‐10 is influenced by cellular interactions of NK cells with DCs and T cells involving DC lysis and costimulation. Thus, NK cells prime both DCs and T cells to low doses of CTLA4‐Ig and IL‐10 during alloimmune responses, providing evidence for the potential interaction between innate and adaptive immunity.
Influence of maternal mass and condition on energy transfer in Weddell seals
Authors: WHEATLEY KATHRYN E. , BRADSHAW COREY J. A. , DAVIS LLOYD S. , HARCOURT ROBERT G. , HINDELL MARK A.
Published: May 2006

Environmental variation influences food abundance and availability, which is reflected in the reproductive success of top predators. We examined maternal expenditure, offspring mass and condition for Weddell seals in 2 years when individuals exhibited marked differences in these traits.

For females weighing  355 kg there was a positive relationship between maternal post‐partum mass (MPPM) and lactation length, but below this there was no relationship, suggesting that heavier females were able to increase lactation length but lighter females were restricted to a minimum lactation period of 33 days.

Overall, females were heavier in 2002, but in 2003 shorter females were lighter than similar‐sized females in 2002 suggesting that the effects of environmental variability on foraging success and condition are more pronounced in smaller individuals.

There was no relationship between MPPM and pup birth mass, indicating pre‐partum investment did not differ between years. However, there was a positive relationship between MPPM and pup mass gain. Mass and energy transfer efficiency were 10·2 and 5·4% higher in 2002 than 2003, which suggests costs associated with a putatively poor‐resource year were delayed until lactation.

Heavier females lost a higher proportion of mass during lactation in both years, so smaller females may not have been able to provide more to their offspring to wean a pup of similar size to larger females.

MPPM had only a small influence on total body lipid; therefore, regardless of mass, females had the same relative body composition. Females with male pups lost a higher percentage of lipid than those with female pups, but by the end of lactation female pups had 4·5% higher lipid content than males.

It appears that for Weddell seals the consequences of environmentally induced variation in food availability are manifested in differences in maternal mass and expenditure during lactation. These differences translate to changes in pup mass and condition at weaning with potential consequences for future survival and recruitment.
Evaluating the power of monitoring plot designs for detecting long‐term trends in the numbers of common guillemots
Authors: SIMS MICHELLE , WANLESS SARAH , HARRIS MICHAEL P. , MITCHELL P. IAN , ELSTON DAVID A.
Published: May 2006

In recent years concerns have been raised regarding the status of the common guillemot Uria aalge in the UK. Numbers have declined in several regions, highlighting the need for continued monitoring of this internationally important population. However, the extent to which the current monitoring scheme is capable of detecting declines and options for improving efficiency has received little attention.

We investigated the power of different monitoring design options for detecting long‐term trends in abundance at a colony of guillemots. The ability to detect trends in abundance was reduced by the large temporal and spatial variability in colony attendance. Taking a linear mixed model approach, we obtained details on the sources and sizes of the variance components using count data collected from monitoring plots on the Isle of May, Scotland, and assessed how best to allocate sampling effort in the light of the count variability structure.

Our results indicated that trend detection will be improved by counting birds in more plots rather than by increasing the number of counts at existing plots.

The revisit pattern of counts at the monitoring plots during the seasonal counting period had little effect on trend detection power. However, given the practical issues associated with counting guillemots, alternative revisit patterns to the current approach are preferred.

For a fixed number of visits per plot, power is strongly influenced by the choice of revisit design if the day‐to‐day variation in colony attendance is increased.

Synthesis and applications. Aspects of the UK seabird monitoring scheme can be improved. Changes to the allocation of sampling effort and the plot‐revisit pattern will improve both the statistical power to detect long‐term trends and the efficiency of conducting the survey. We stress the importance of considering the structure and magnitude of the count variation in a power analysis because judicious design decisions depend on the relative magnitude of these variance components.
A fungal endophyte of black spruce (Picea mariana) needles is also an aquatic hyphomycete
Authors: SOKOLSKI SERGE , PICHÉ YVES , CHAUVET ÉRIC , BÉRUBÉ JEAN A.
Published: May 2006

An aquatic hyphomycete, Dwayaangam sp., was isolated from superficially sterilized black spruce (Picea mariana) needles submerged in aerated water in a small glass chamber (microcosm). The internal transcribed spacer (ITS) sequence of this fungus and of a commonly encountered foliar endophyte isolated from P. mariana showed a high degree of similarity. When sporulation was induced in the microcosm, both the aquatic hyphomycete and the endophyte isolate produced similar aquatic conidia after 30 days, which is longer than previously documented in similar studies. Without the use of molecular tools, the link between the aquatic and endophytic phases of the fungus would have gone unnoticed. This is the first time that a fungal endophyte of conifer needles has been shown to have an aquatic phase. Its presence both as a foliar endophyte and a sporulating aquatic fungus suggests an alternating life cycle between the two environments.
Genetic differentiation in relation to marine landscape in a broadcast‐spawning bivalve mollusc (Placopecten magellanicus)
Authors: KENCHINGTON E. L. , PATWARY M. U. , ZOUROS E. , BIRD C. J.
Published: May 2006

Marine bivalves are sessile or sedentary as adults but have planktonic larvae which can potentially disperse over large distances. Consequently larval transport is expected to play a prominent role in facilitating gene flow and determining population structure. The sea scallop (Placopecten magellanicus) is a dioecious species with high fecundity, broadcast spawning and a c. 30‐day planktonic larval stage, yet it forms discrete populations or ‘beds’ which have significantly different dynamics and characteristics. We analysed variation at six microsatellite loci in 12 locations throughout the geographic range of the species from Newfoundland, Canada, to New Jersey, USA. Significant differentiation was present and the maximum pairwise θ value, between one of the Newfoundland samples in the north and a sample from the southern portion of the range, was high at 0.061. Other proximate pairs of samples had no detectable genetic differentiation. Mantel tests indicated a significant isolation by distance, but only when one of the populations was excluded. A landscape genetic approach was used to detect areas of low gene flow using a joint analysis of spatial and genetic information. The two major putative barriers inferred by Monmonier's algorithm were then used to define regions for an analysis of molecular variance (amova). That analysis showed a significant but low percentage (1.2%) of the variation to be partitioned among regions, negligible variation among populations within regions, and the majority of the variance distributed between individuals within populations. Prominent currents were concordant with the demarcation of the regions, while a novel approach of using particle tracking software to mimic scallop larval dispersal was employed to interpret within‐region genetic patterns.
11 Gastric myoelectric activity while viewing and eating food in obese participants
Authors: WANG JY , STERN RM
Published: May 2006

Purpose:  This study observed the reactions of the stomach to food viewing and food eating in obese people.

Method:  The participants were 20 obese (mean BMI of 32) and 20 normal‐weighted (mean BMI of 21) undergraduate students, who were required to fast for at least 4 hours preceding the experiment. They viewed a video clip of food for 6 minutes; consumed food till full; and viewed the same video clip of food 30 minutes after the meal. Cutaneous electrogastrograms (EGGs) were recorded during the entire procedure. Questionnaires concerning the participants’ perception of somatic and affective changes during the tasks were completed.

Results:  The percentages of bradygastric, normal and tachygastric EGG activity were very similar between obese group and normal‐weighted group during the baseline period. During the first food image viewing, an increase in normal 3 cpm activity and a decreased in bradygastric activity occurred in both groups, but obese participants showed less of an increase in 3 cpm activity than normal‐weighted participants and the percentage of bradygastric activity was higher in obese group than in the normal‐weighted group. During the 30 min. period following the meal, a higher percentage of bradygastric activity and a lower percentage of 3 cpm activity were observed in obese participants than in normal‐weighted participants. Furthermore, obese participants showed a different pattern of change in 3 cpm and bradygastric activity than normal‐weighed participants during the 30 min. The whole 30‐min period was divided into five 6‐min periods. In the obese group, the percentage of 3 cpm activity decreased in the third and forth 6‐min periods and increased to the highest level in the last 6‐min period, while in the normal‐weighted group, the 3 cpm percentage was the greatest in the first 6‐min period. Obese participants and normal‐weighted participants reacted similarly to the second food image exposure, except that a higher increase in 3 cpm activity was observed in the normal‐weighted group in the period after the termination of viewing the food images.

Conclusions:  These data suggest that obese people react to food images and to food eating differently from normal‐weighted people. EGG activity in obese participants needs further investigation.
19 Electrogastrography differentiates enteric myopathy from neuropathy in adults with severe motility disorders of the gut
Authors: ABID S , LINDBERG G
Published: May 2006

Background:  Chronic intestinal pseudo‐obstruction, enteric dysmotility and slow transit constipation are severe motility disorders of the gut that usually are associated with an underlying enteric neuropathy or myopathy. Electrogastrography (EGG) is a non‐invasive technique that records gastric myoelectric activity.

Aim of the study:  To determine whether EGG can differentiate enteric myopathy from neuropathy as the primary pathology in patients with severe motility disorders of the gut.

Material and methods:  This is a retrospective analysis of patients with various motility disorders of the gut that underwent full thickness small bowel biopsy. A single bipolar channel measured the EGG. The ability of EGG to differentiate between myopathy and neuropathy was tested by comparing 21 variables from EGG.

Results:  A total of 38 patients, 35 (92%) females, mean age 42 ± 13 years, were analysed. Twenty patients had enteric dysmotility (19 with neuropathy and one with myopathy), 12 had slow transit constipation (10 with neuropathy and two with myopathy), and six had chronic intestinal pseudo‐obstruction (three with neuropathy and three with myopathy). Patients with myopathy showed higher percentage of fasting time with DF in bradygastric and tachygastric frequency bands and a higher postprandial DF (Table) than did patients with neuropathic motility disorders.

Conclusions:  Patients with visceral myopathy exhibited more arrhythmia during fasting and a higher DF following the test meal and this indicates that myopathies are associated with more electrical disturbances than neuropathies. EGG may be considered for differentiating between these two disease entities.

 Comparison of EGG parameters in visceral myopathy and neuropathy

EGG parameter
Myopathy N = (6)
Neuropathy N = (32)
P value

Fasting bradygastria%α
 9 (3–14)
 0 (0–15)
<0.001

Fasting tachygastria%α
24 (3–42)
 8 (0–69)
<0.05

Fasting normal%α
56 (19–94)
88 (31–100)
<0.001

Postprandial DF
 3.9 ± 2.5
 3.1 ± 0.1
<0.05

DF: Dominant Frequency; α median and range.