bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of natural interferon‐producing cells and T lymphocytes in porcine monocyte‐derived dendritic cell maturation
Authors: Guzylack‐Piriou Laurence , Piersma Sytse , McCullough Kenneth , Summerfield Artur
Published: March 2006

Maturation of dendritic cells (DC) is a key immunological process regulating immune responses to pathogens and vaccines, as well as tolerance and autoimmune processes. Consequently, the regulation of DC maturation should reflect these multifaceted immunological processes. In the present study, we have defined the role of particular cytokines, Toll‐like receptor (TLR) ligands and T lymphocytes in the porcine monocyte‐derived DC (MoDC). Interferon‐α (IFN‐α) alone was a poor inducer of MoDC maturation, but in association with tumour necrosis factor‐α (TNF‐α), or TLR ligands such as lipopolysaccharide and polyinosinic‐polycytidylic acid I:C, an up‐regulation of major histocompatibility complex II and CD80/86 expression was noted, along with reduced endocytic activity. In contrast, TNF‐α alone or in combination with the TLR ligands was a poor inducer of DC maturation, but co‐operated with T‐lymphocytes in the presence of antigen to induce DC maturation. Natural interferon producing cells (NIPC, or plasmacytoid DCs) represent a danger‐recognition system of the immune defences, and can respond to viruses not otherwise recognized as posing a danger. Indeed, MoDC did not respond to transmissible gastroenteritis virus (TGEV), whereas NIPC produced high levels of IFN‐α and TNF‐α after TGEV stimulation. Moreover, supernatants from the stimulated NIPC induced maturation in MoDCs. These matured MoDCs displayed an enhanced ability to present antigen to and thus stimulate T cells. Taken together, the present work demonstrates that maturation of MoDC not only results from TLR signalling, but can require co‐operation with various cell types – principally NIPC and activated T cells – which would reflect the particular immunological situation.
Extending point pattern analysis for objects of finite size and irregular shape
Authors: WIEGAND THORSTEN , KISSLING W. DANIEL , CIPRIOTTI PABLO A. , AGUIAR MARTÍN R.
Published: March 2006

We use a grid‐ and simulation‐based approach to extend point pattern analysis to deal with plants of finite size and irregular shape, and compare the results of our approach with that of the conventional point approximation. The plants are approximated by using an underlying grid and may occupy several adjacent grid cells depending on their size and shape. Null models correspond to that of point pattern analysis but need to be modified to account for the finite size and irregular shape of plants.

We use a mapped area of a grass‐shrub steppe in semi‐arid Patagonia, Argentina, to show that the shrub community is essentially randomly structured, but that shrubs facilitate grasses in their immediate neighbourhood.

The occurrence of this random spatial structure provides important new information on the biology of shrub populations. In general, previous data from semi‐arid and arid ecosystems have shown that adult shrubs tend to show over‐dispersed patterns, whereas juveniles are clumped.

We find that the point approximation may produce misleading results (i) if plant size varies greatly, (ii) if the scale of interest is of the same order of magnitude as the size of the plants, and (iii) if the plants of a given pattern are constrained through competition for space by the presence of other plants. The point approximation worked well in all other cases, but usually depicted weaker significant effects than when the size and shape of plants were taken into account.

Our approach to quantifying small‐scale spatial patterns in plant communities has broad applications, including the study of facilitation and competition. Ecologists will be able to use the software available to take advantage of these methods.
The evolution of rewards: seed dispersal, seed size and elaiosome size
Authors: EDWARDS WILL , DUNLOP MICHAEL , RODGERSON LOUISE
Published: March 2006

We examine the relationship between the reward offered to ants to disperse seeds (elaiosome size) and seed size, and the possible mechanisms that may generate this relationship in Australian plant species.

We used seed and elaiosome sizes from our own data set containing 87Acaciaspecies, supplemented with 22 species from a previously published data set, and 98 ‘Other species’ from 51 genera in 25 families, also from published data.

The relationship between ln(elaiosome size) and ln(seed size) was determined using standard major axis (SMA) regression for both data sets. For the Other data set we also determined the relationship among species independent of the differences between genera, among genera independent of the differences between families, among genera and among families. We used SMA to test for differences in slopes between groups.

We found a significant common slope amongst all subsets of the larger data set. The estimated common slope and the 95% confidence interval for the relationship between ln(elaiosome size) and ln(seed size) across all data sets fell above one (1.24, 95%CI = 1.17–1.32), suggesting positive allometry. Slopes were also significantly positive and strikingly similar between theAcaciaspecies data set and the Other species data sets. Similar positive allometry was shown in the ‘other’ species data set among genera and families, and among species independent of genus means (‘species effects’).

Significant and consistent relationships between taxonomic levels, independent of relationships at other levels, along with significant relationships at the species level, and similarity of slopes, suggest independent convergence towards an underlying functional relationship that has persisted over long evolutionary periods. Our results therefore suggest that ants have been agents of selection on seed traits.

Such a functional relationship might result from a trade‐off in ant foraging behaviour between the benefit of the reward (elaiosome) and the cost of the dispersal (determined by seed size). Slopes > 1 would then suggest that ants need more than proportionally larger rewards to remove larger seeds.
Root competition: beyond resource depletion
Authors: SCHENK H. JOCHEN
Published: March 2006

Root competition is defined as a reduction in the availability of a soil resource to roots that is caused by other roots. Resource availability to competitors can be affected through resource depletion (scramble competition) and by mechanisms that inhibit access of other roots to resources (contest competition, such as allelopathy).

It has been proposed that soil heterogeneity can cause size‐asymmetric root competition. Support for this hypothesis is limited and contradictory, possibly because resource uptake is affected more by the amount and spatial distribution of resource‐acquiring organs, relative to the spatial distribution of resources, than by root system sizeper se.

Root competition intensity between individual plants generally decreases as resource availability (but not necessarily habitat productivity) increases, but the importance of root competition relative to other factors that structure communities may increase with resource availability.

Soil organisms play important, and often species‐specific, roles in root interactions.

The findings that some roots can detect other roots, or inert objects, before they are contacted and can distinguish between self and non‐self roots create experimental challenges for those attempting to untangle the effects of self/non‐self root recognition, self‐inhibition and root segregation or proliferation in response to competition. Recent studies suggesting that root competition may represent a ‘tragedy‐of‐the‐commons’ may have failed to account for this complexity.

Theories about potential effects of root competition on plant diversity (and vice versa) appear to be ahead of the experimental evidence, with only one study documenting different effects of root competition on plant diversity under different levels of resource availability.

Roots can interact with their biotic and abiotic environments using a large variety of often species‐specific mechanisms, far beyond the traditional view that plants interact mainly through resource depletion. Research on root interactions between exotic invasives and native species holds great promise for a better understanding of the way in which root competition may affect community structure and plant diversity, and may create new insights into coevolution of plants, their competitors and the soil community.
Seed predation, not seed dispersal, explains the landscape‐level abundance of an early‐successional plant
Authors: ORROCK JOHN L. , LEVEY DOUGLAS J. , DANIELSON BRENT J. , DAMSCHEN ELLEN I.
Published: March 2006

Plants may not occur in a given area if there are no suitable sites for seeds to establish (microsite limitation), if seeds fail to arrive in suitable microsites (dispersal limitation) or if seeds in suitable microsites are destroyed by predators (predator limitation).

We conducted a large‐scale study to determine the importance of dispersal limitation and predator limitation in affecting the distribution of pokeweed, Phytolacca americana, in 401‐ha experimental patches arrayed in eight groups of five patches distributed across a 300‐km2 region.

Microsite limitation was minimized by clearcutting and burning existing vegetation, creating the type of disturbed habitat in which P. americana readily germinates and establishes. The role of dispersal limitation was examined by adding approximately 7000 seeds to each of eight patches in March 2000. The role of seed predation was examined in all 40 patches using experimental exclosures from June 2000 to July 2001.

The number of P. americana plants in September 2000 was unchanged by seed addition. However, fewer P. americana plants were found in patches where seed predators removed more P. americana seeds from experimental exclosures. These data suggest that P. americana is not limited by seed dispersal. Rather, in habitats where microsites are readily available, the abundance of P. americana among patches appears to be limited by the activities of seed predators.

When dispersal and microsites are not limiting, the role of local seed predators can be important for generating emergent, large‐scale patterns of plant abundance across landscapes. Moreover, because predators may generate large‐scale patterns that resemble other forms of limitation and predators may target specific species, predator impacts should be more frequently incorporated into experiments on the role of seed limitation and plant community composition.
Diurnal variation of prescribing pattern of primary care doctors in Bahrain
Authors: Damanhori Awatif H. H. , Al Khaja Khalid A. J. , Sequeira Reginald P. , Al‐Ansari Thuraya M.
Published: March 2006

Rationale, aims and objectives  To evaluate the variation in prescribing by primary care doctors during the morning and the evening clinics and to determine whether these prescribing patterns are influenced by doctors’ training background.

Methods  A retrospective prescription‐based study was carried out in 17 out of 20 primary care health centres in Bahrain distributed across the Kingdom.

Results  A total of 4472 prescriptions containing 10 588 drug‐items covering the prescribing practice of approximately 90% primary care doctors were analysed. Paracetamol was the most commonly prescribed drug in both clinics. Drugs such as diclofenac sodium, amoxycillin, ibuprofen, chlorpheniramine, hyoscine butylbromide, Actifed®, Benylin® and xylometazoline were the most commonly prescribed drugs to patients attending morning and evening clinics with a considerable variation in ordinal ranking of proportions. As regards morning clinic, chlorpheniramine and Fefol® were prescribed by the family doctors (FDs) more often than by the general practitioners (GPs) (P < 0.05), whereas, multivitamins were prescribed by the GPs more often than by the FDs (P = 0.001). During the evening clinic, however, ibuprofen, chlorpheniramine, bromhexine and xylometazoline were prescribed by the FDs in a rate significantly higher than that prescribed by the GPs (P < 0.05). The prevalence of acute and/or chronic morbidities in patient attending clinics was estimated based on the therapeutic indication for drugs used. The mean number of drugs per prescription was 2.41 ± 1.3. Prescriptions containing three or more drugs comprised 41.7% of all prescriptions. The GPs had a greater tendency to practice polypharmacy than the FDs.

Conclusion  A significant diurnal variation in prescribing, and polypharmacy practice were related to the training background of the doctors. This quantitative study provides the baseline data for monitoring primary care prescribing practices in Bahrain. To further evaluate the underlying factors that influence drug use indicators, a qualitative study is needed.
Low testosterone levels are associated with carotid atherosclerosis in men
Authors: SVARTBERG J. , VON MÜHLEN D. , MATHIESEN E. , JOAKIMSEN O. , BØNAA K. H. , STENSLAND‐BUGGE E.
Published: March 2006

Objective.  To study the relationship between endogenous sex hormone levels and intima‐media thickness (IMT) of the carotid artery measured by ultrasonography.

Design.  Population‐based cross‐sectional study.

Methods.  Sex hormone levels measured by immunoassay, anthropometric measurements and IMT was studied in 1482 men aged 25–84 years participating in the 1994–1995 Tromsø study. The data were analysed with partial correlation, multiple linear regression and logistic regression analysis.

Results.  Linear regression models showed that total testosterone and sex hormone‐binding globulin levels, but not calculated free testosterone, serum oestradiol or dehydroepiandrosterone sulphate levels were inversely associated with the age‐adjusted IMT (P = 0.008 and P < 0.001 respectively). These associations were independent of smoking, physical activity, blood pressure and lipid levels, but were not independent of body mass index (BMI). Excluding men with cardiovascular disease (CVD) did not materially change these results. In a logistic regression model adjusted for the confounding effect of CVD risk factors, men with testosterone levels in the lowest quintile (<9.0 nmol L−1) had an independent OR = 1.51 (P = 0.015) of being in the highest IMT quintile.

Conclusions.  We found an inverse association between total testosterone levels and IMT of the carotid artery in men that was present also after excluding men with CVD, but was not independent of BMI. The clinical relevance of this, however, is uncertain and needs to be investigated in a clinical setting.
Diet and physical activity in relation to overall mortality amongst adult diabetics in a general population cohort
Authors: TRICHOPOULOU A. , PSALTOPOULOU T. , ORFANOS P. , TRICHOPOULOS D.
Published: March 2006

Objectives.  To evaluate the effect on overall and cardiovascular mortality of diet and physical activity amongst diabetic persons.

Design.  Population‐based prospective investigation, from 1993 to mid‐2004, in the Greek arm of the European Prospective Investigation into Cancer and Nutrition.

Setting.  Volunteers from the general adult Greek population.

Subjects.  From an original sample of 28 572 volunteers, 1013 were taking at enrolment drugs for diabetes mellitus, had no missing information on the study variables and no comorbidity. Diet was assessed at baseline through a validated questionnaire. Proportional hazards regression was used to assess the relation of dietary factors and physical activity with mortality.

Interventions.  None.

Main outcome measures.  Mortality ratios overall and from cardiovascular causes.

Results.  During 4579 person‐years, 80 deaths have occurred, 46 of which from cardiovascular causes. Physical activity was strongly inversely associated with mortality. Two nutritional variables were significantly associated with diabetic mortality, with hazard ratios for increases of daily intake by one standard deviation being 1.31 for eggs [95% confidence interval (95% CI) 1.07 to 1.60] and 1.82 for saturated lipids (95% CI, 1.14 to 2.90). These two associations were considerably stronger for cardiovascular mortality. Waist‐to‐height ratio was positively, whereas hip circumference inversely associated with mortality. No significant interactions with gender for any of the study variables were evident.

Discussion.  Amongst confirmed diabetic persons, increased physical activity is associated with significant reduction of mortality, whereas increased consumption of eggs and saturated fats is associated with significant increase of mortality. Monounsaturated lipids are preferable for diabetic persons.
Radiographic measure of aorta calcification is a site‐specific predictor of bone loss and fracture risk at the hip
Authors: BAGGER Y. Z. , TANKÓ L. B. , ALEXANDERSEN P. , QIN G. , CHRISTIANSEN C. ,   THE PROSPECTIVE EPIDEMIOLOGICAL RISK FACTORS STUDY GROUP
Published: March 2006

Objective.  To investigate whether aorta calcification (AC) – a surrogate marker of atherosclerosis – is an independent indicator of low bone mass density (BMD), accelerated bone loss, and risk of future fractures in postmenopausal women.

Design.  A prospective epidemiological study. Follow‐up period was 7.5 years.

Setting.  Community‐based sample followed by a research institute.

Subjects.  A total of 2662 generally healthy postmenopausal women with a mean age of 65.0 ± 7.1 years at baseline.

Main outcome measures.  Annual rate of changes in BMD (DEXA) and AC (X‐rays), vertebral fractures (X‐rays), hip fractures (questionnaire).

Results.  Advanced AC at baseline was significantly associated with lower BMD and accelerated bone loss from the proximal femur. In a multivariate logistic regression model, age (OR 1.1, 95% CI 1.0–1.2, P = 0.02), body mass index (BMI; OR 0.9, 95% CI 0.8–1.0, P = 0.03) and the severity of AC (OR 2.3, 95% CI 1.1–4.8, P = 0.03) were independent predictors of hip fractures. Adjusted OR for vertebral fracture was 1.2 (95% CI 1.0–1.5, P = 0.12).

Conclusions.  Aorta calcification seems to independently contribute to the development of osteoporosis in the proximal femur. Further studies are needed to clarify whether effective atherosclerosis prevention lowers hip fracture risk.
Epidermal Growth Factor Receptor Expression and Activation in Neuroendocrine Tumours
Authors: Shah T. , Hochhauser D. , Frow R. , Quaglia A. , Dhillon A. P. , Caplin M. E.
Published: March 2006

Epidermal growth factor receptor (EGFR) is expressed in many cancers and is associated with poor prognosis. EGFR activation pathways have been well characterised using tumour cell lines and are known to involve EGFR activation through autophosphorylation. Phosphorylation of downstream signalling molecules, such as ERK1/2 (extra‐cellular regulated kinase 1 and 2) and PKB/Akt (protein kinase B), leads to enhanced tumour cell survival and proliferation. Although EGFR expression has been determined in neuroendocrine tumour tissue, its activation and subsequent effects on the downstream signalling molecules, ERK1/2 and Akt, have not been studied. We therefore planned to determine the role of EGFR in neuroendocrine tumours (NETs) by determining its pattern of expression and activation, and the subsequent activation of downstream signalling molecules ERK1/2 and Akt. Paraffin‐embedded tumour tissue was available from 98 patients with NETs (39 foregut, 42 midgut, four hindgut, five paragangliomas, and four of unknown origin). Immunohistochemical evaluation was performed for the expression of EGFR, p‐EGFR, p‐Akt, and p‐ERK1/2. Ninety‐six percent of tumour samples were positive for EGFR expression; 63% were positive for activated EGFR; 76% were positive for activated Akt; and 96% were positive for activated ERK1/2. Importantly, the histological score for the activation of Akt and ERK1/2 correlated with the histological score for activated EGFR. These data provide a rationale for considering EGFR inhibitors in the treatment of NETs. Additionally, direct inhibition of Akt and ERK1/2 may provide further therapeutic options in the treatment of NETs in the future.
Information Processing in the Hypothalamus: Peptides and Analogue Computation
Authors: Leng G. , Ludwig M.
Published: March 2006

‘Lovers and madmen have such seething brains,/Such shaping fantasies, that apprehend/More than cool reason ever comprehends’(A Midsummer Night's Dream, Act V Scene I)

Peptides in the hypothalamus are not like conventional neurotransmitters; their release is not particularly associated with synapses, and their long half‐lives mean that they can diffuse to distant targets. Peptides can act on their cells of origin to facilitate the development of patterned electrical activity, they can act on their neighbours to bind the collective activity of a neural population into a coherent signalling entity, and the co‐ordinated population output can transmit waves of peptide secretion that act as a patterned hormonal analogue signal within the brain. At their distant targets, peptides can re‐programme neural networks, by effects on gene expression, synaptogenesis, and by functionally rewiring connections by priming activity‐dependent release.
Enhanced vertical alveolar bone augmentation by recombinant human bone morphogenetic protein‐2 with a carrier in rats
Authors: SHIMAZU C. , HARA T. , KINUTA Y. , MORIYA K. , MARUO Y. , HANADA S. , MINAGI S.
Published: March 2006

summary  This study aimed to evaluate the effect of recombinant human bone morphogenetic protein‐2 (rhBMP‐2) on vertical bone regeneration of edentulous ridge. Bilateral upper first and second molars of 8‐week‐old Wistar rats were extracted and the ridges were allowed to heal for 3 weeks. Compressed poly(lactic‐co‐glycolic acid) copolymer/gelatin sponge (PGS) was used as a carrier of rhBMP‐2. PGS alone (control group) or PGS with 5 μg rhBMP‐2 (test group) was implanted at the top part of alveolar ridge. The sham group received no implantation. The rats were killed at 1, 2, 4, 8 and 12 weeks after implantation and examined histologically and histomorphometrically. In the test group, significant bone augmentation was evident on the alveolar ridge throughout the experimental period. Histomorphometric analysis revealed greater tissue volume and height of alveolar bone in the test group compared with the control and sham groups (P < 0·05) from 4 weeks onward and the augmented tissues (5 mm3 in tissue volume and 1·5 mm in bone height) were maintained until 12 weeks. Osteoblast surface increased at 2 and 4 weeks and osteoid thickness reached a peak (25 μm) at 2 weeks. Dynamic variables, which represented calcification, were higher in the test group than the control and sham groups at 4 and 8 weeks (P < 0·05). These results suggest that use of rhBMP‐2/PGS may achieve vertical bone augmentation, and stabilizes denture prosthesis or makes up for inadequate bone mass for implant prosthesis.
FAST‐TRACK: A southern California freeway is a physical and social barrier to gene flow in carnivores
Authors: RILEY SETH P. D. , POLLINGER JOHN P. , SAUVAJOT RAYMOND M. , YORK ERIC C. , BROMLEY CASSITY , FULLER TODD K. , WAYNE ROBERT K.
Published: March 2006

Roads present formidable barriers to dispersal. We examine movements of two highly mobile carnivores across the Ventura Freeway near Los Angeles, one of the busiest highways in the United States. The two species, bobcats and coyotes, can disappear from habitats isolated and fragmented by roads, and their ability to disperse across the Ventura Freeway tests the limits of vertebrates to overcome anthropogenic obstacles. We combine radio‐telemetry data and genetically based assignments to identify individuals that have crossed the freeway. Although the freeway is a significant barrier to dispersal, we find that carnivores can cross the freeway and that 5–32% of sampled carnivores crossed over a 7‐year period. However, despite moderate levels of migration, populations on either side of the freeway are genetically differentiated, and coalescent modelling shows their genetic isolation is consistent with a migration fraction less than 0.5% per generation. These results imply that individuals that cross the freeway rarely reproduce. Highways and development impose artificial home range boundaries on territorial and reproductive individuals and hence decrease genetically effective migration. Further, territory pile‐up at freeway boundaries may decrease reproductive opportunities for dispersing individuals that do manage to cross. Consequently, freeways are filters favouring dispersing individuals that add to the migration rate but little to gene flow. Our results demonstrate that freeways can restrict gene flow even in wide‐ranging species and suggest that for territorial animals, migration levels across anthropogenic barriers need to be an order of magnitude larger than commonly assumed to counteract genetic differentiation.
Extracytoplasmic prosthetic group ligation to apoproteins: maturation of c‐type cytochromes
Authors: Turkarslan Serdar , Sanders Carsten , Daldal Fevzi
Published: March 2006

In all organisms, haem is post‐translationally and covalently attached to c apocytochromes to produce c holocytochromes via a process called c‐type cytochromes maturation, which involves numerous components. In bacteria it was not clear which of these components catalyses the extracytoplasmic haem–apocytochrome ligation per se. In this issue of Molecular Microbiology, Feissner and colleagues report that a single polypeptide from Helicobacter pylori, corresponding to the fusion of two proteins found in other organisms, performs haem ligation to a coexpressed Bordetella pertussis apocytochrome c in an Escherichia coli mutant lacking its own cytochrome c maturation proteins. This simple experimental system pinpoints the components catalysing extracytoplasmic covalent haem ligation and raises intriguing issues about the requirements for delivery of haem and apocytochrome c substrates to produce c holocytochromes.
Interactions between C ring proteins and export apparatus components: a possible mechanism for facilitating type III protein export
Authors: González‐Pedrajo Bertha , Minamino Tohru , Kihara May , Namba Keiichi
Published: March 2006

The flagellar switch proteins of Salmonella, FliG, FliM and FliN, participate in the switching of motor rotation, torque generation and flagellar assembly/export. FliN has been implicated in the flagellar export process. To address this possibility, we constructed 10‐amino‐acid scanning deletions and larger truncations over the C‐terminal domain of FliN. Except for the last deletion variant, all other variants were unable to complement a fliN null strain or to restore the export of flagellar proteins. Most of the deletions showed strong negative dominance effects on wild‐type cells. FliN was found to associate with FliH, a flagellar export component that regulates the ATPase activity of FliI. The binding of FliM to FliN does not interfere with this FliN–FliH interaction. Furthermore, a five‐protein complex consisting of FliG, His‐tagged FliM, FliN, FliH and FliI was purified by nickel‐affinity chromatography. FliJ, a putative general chaperone, is bound to FliM even in the absence of FliH. The importance of the C ring as a possible docking site for export substrates, chaperones and FliI through FliH for their efficient delivery to membrane components of the export apparatus is discussed.
Evolution of mutation rates in bacteria
Authors: Denamur Erick , Matic Ivan
Published: March 2006

Evolutionary success of bacteria relies on the constant fine‐tuning of their mutation rates, which optimizes their adaptability to constantly changing environmental conditions. When adaptation is limited by the mutation supply rate, under some conditions, natural selection favours increased mutation rates by acting on allelic variation of the genetic systems that control fidelity of DNA replication and repair. Mutator alleles are carried to high frequency through hitchhiking with the adaptive mutations they generate. However, when fitness gain no longer counterbalances the fitness loss due to continuous generation of deleterious mutations, natural selection favours reduction of mutation rates. Selection and counter‐selection of high mutation rates depends on many factors: the number of mutations required for adaptation, the strength of mutator alleles, bacterial population size, competition with other strains, migration, and spatial and temporal environmental heterogeneity. Such modulations of mutation rates may also play a role in the evolution of antibiotic resistance.
A re‐examination of the minor role of unstirred layers during the measurement of transport coefficients of Chara corallina internodes with the cell pressure probe
Authors: YE QING , KIM YANGMIN , STEUDLE ERNST
Published: March 2006

The impact of unstirred layers (USLs) during cell pressure probe experiments with Chara corallina internodes has been quantified. The results show that the hydraulic conductivity (Lp) measured in hydrostatic relaxations was not significantly affected by USLs even in the presence of high water flow intensities (‘sweep‐away effect’). During pressure clamp, there was a reversible reduction in Lp by 20%, which was explained by the constriction of water to aquaporins (AQPs) in the C. corallina membrane and a rapid diffusional equilibration of solutes in arrays where water protruded across AQPs. In osmotic experiments, Lp, and permeability (Ps) and reflection (σs) coefficients increased as external flow rate of medium increased, indicating some effects of external USLs. However, the effect was levelling off at ‘usual’ flow rates of 0.20–0.30 m s−1 and in the presence of vigorous stirring by air bubbles, suggesting a maximum thickness of external USLs of around 30 µm including the cell wall. Because the diameters of internodes were around 1 mm, internal USLs could have played a significant or even a dominating role, at least in the presence of the rapidly permeating solutes used [acetone, 2‐propanol and dimethylformamide (DMF)]. A comparison of calculated (diffusion kinetics) and of measured permeabilities indicated an upper limit of the contribution of USLs for the rapidly moving solute acetone of 29%, and of 15% for the less rapidly permeating DMF. The results throw some doubt on recent claims that in C. corallina, USLs rather than the cell membrane dominate solute uptake, at least for the most rapidly moving solute acetone.
Analysis of deaths with an unknown cause in epidemiologic analyses of mortality burden
Authors: Rowe Alexander K.
Published: March 2006

Objective  To describe options for analysing deaths with an unknown cause, which often occur in community‐based studies that are used to estimate disease‐specific mortality burden and trends in low‐income countries.

Methods  Mathematical formulae were derived that accommodate deaths with an unknown cause for the disease‐specific mortality rate, proportion of deaths attributable to the disease and all‐cause mortality rate. Seven specific options are presented, including example calculations from a study of childhood malaria mortality in The Gambia. An algorithm is proposed to help make decisions on analysing deaths with an unknown cause.

Results  In the Gambian study, 25.2% of deaths had an unknown cause. Three options would result in 23.6% (minimum), 48.8% (maximum) and 28.7% (probably the best estimate) of deaths attributed to malaria. The best analysis option depends on the disease of interest: diseases for which the diagnostic method has high sensitivity and specificity (e.g., measles, neonatal tetanus) are best analysed assuming that deaths with an unknown cause never have this cause, while diseases for which specificity and/or sensitivity is low (e.g., malaria) are likely to account for some proportion of deaths with an unknown cause.

Conclusions  The most important aspects of analysing deaths with unknown cause are choosing appropriate assumptions, describing them explicitly and performing a sensitivity analysis. Studies of causes of death should report several key pieces of information on deaths with unknown cause to aid interpretation.
Comparison of family reporting of pregnancy status with a post‐mortemβ‐HCG test in deceased women: a study in Pointe‐Noire, Congo
Authors: Le Coeur Sophie , Ronsmans Carine , Halembokaka Gaston , Augereau‐Vacher Christine , Khlat Myriam
Published: March 2006

Objective  To compare family reports of pregnancy status in deceased women with a biological assessment of pregnancy using a post‐mortem β‐HCG test.

Method  We investigated the deaths of females of reproductive age registered at the Pointe Noire morgue from June 30 to October 18, 2001. A physician interviewed relatives about the circumstances of death, in particular whether the woman had been pregnant at the time of death, and whether she had delivered or had an abortion (induced or spontaneous) within the past 6 weeks. The bodies were then examined and blood samples taken for β‐HCG testing.

Results  Among 368 deaths of women of reproductive age registered, 34 deaths were identified as pregnancy‐related: 23 by both the family interview and the β‐HCG test, five by β‐HCG test only and six were β‐HCG negative but the family had reported a recent delivery.

Conclusion  In this setting, the approach based on family reports underestimates mortality during pregnancy by 24% and mortality during pregnancy or within 6 weeks postpartum by 15%.
Malaria prevention in The Gambia: patterns of expenditure and determinants of demand at the household level
Authors: Wiseman V. , McElroy B. , Conteh L. , Stevens W.
Published: March 2006

Objective  To provide a better understanding of (1) the amounts households in The Gambia spend on a wide variety of malaria prevention measures, (2) how expenditure fluctuates throughout the year and (3) the main determinants of expenditure.

Methods  A random sample of 1700 households from the Farafenni region were interviewed about their expenditure on malaria prevention over the past 2 weeks. Interviews were staggered over 12 months. Expenditure was measured for bed nets, treating and repairing bed nets, aerosols, coils, indoor spraying, smoke and other prevention strategies such as drinking herbs and cleaning the outside environment.

Results  Expenditure on bed nets, including treatment and repair, constituted only 10% of total expenditure on malaria prevention. Every fortnight, households spent an average of 8.40 Dalasis (D) on coils, 4.20 D on indoor sprays, 3.09 D on smoke and 3.06 D on aerosols, together making up 81% of total fortnightly expenditure. Of the 442 households that did not own a bed net, 68% said it was because they could not afford one. Every 2 months, the same households spent an average of US$5, the equivalent to the cost of an insecticide treated bed net, on other forms of prevention. Total expenditure was 42% higher during the wet season than for the rest of the year. For every month of the year, coils were the dominant form of prevention expenditure. Wealth, age, occupation of household head, location of residence and month of the year were significant determinants of prevention expenditure.

Conclusions  Households in The Gambia spend considerable amounts on a range of malaria prevention products and activities throughout the year. Bed nets represent a relatively small proportion of this expenditure even though they are perceived to be the most efficient and effective method of malaria control. A more concerted effort is needed to develop appropriate targeting strategies to encourage bed net use especially for children <5 years of age. Equal emphasis should be given to addressing barriers to purchasing nets such as their relative high upfront cost.
The treatment of psoriasis vulgaris: 1% topical methotrexate gel
Authors: Eskicirak Buket , Zemheri Ebru , Cerkezoglu Arzu
Published: March 2006

Background  In general, 70% of patients with psoriasis prefer topical therapy as the treatment of choice.

Aim  To evaluate the efficacy and tolerability of 1% topical methotrexate gel vs. placebo (vaseline ointment) as treatment for psoriasis.

Methods  Forty patients (20 females and 20 males) with chronic plaque‐type psoriasis joined the study. Each patient was allocated to apply 1% methotrexate gel and placebo topically to their two target lesions, equal in area and disease severity, twice daily for 8 weeks. Lesions were scored at baseline and after 2, 4, 6, and 8 weeks of treatment for erythema, scale, and infiltration. The global improvement and histopathologic features were also assessed after methotrexate treatment.

Results  At the end of treatment, erythema was cleared totally in 47.5% of patients treated with methotrexate vs. 7.5% of those treated with placebo, and infiltration in 22% of patients treated with methotrexate vs. 2.5% of those treated with placebo (P < 0.01). Clinical improvement was almost the same for the two groups with regard to scale (P < 0.5). The global improvement was 97% for patients treated with methotrexate vs. 60% for those treated with placebo, and a significant difference was found between the groups (P < 0.01). Histopathologic improvement was achieved in the methotrexate group (P < 0.01). No side‐effects were observed.

Conclusion  The findings of this study suggest that methotrexate 1% in a hydrophilic gel is well tolerated and significantly more effective than placebo as a topical medication for the treatment of psoriasis vulgaris.
Eosinophilic panniculitis: Report of three cases
Authors: Liu Y. , Xiao S. X. , Wang J. M. , Peng Z. H. , Feng Y. G. , Lei X. B. , Wang Q. , Liu A. , Jiao T.
Published: March 2006

Eosinophilic panniculitis, characterized by a prominent infiltration of subcutaneous fat with eosinophils, has been identified in patients with a variety of associated clinical conditions. Burket and Burket reported the first case in 1985.1 To our knowledge, more than 30 additional patients have been described since this initial case report. The study of 18 patients with biopsy diagnoses of eosinophilic panniculitis by Winkelmann, et al. in 1986 revealed diverse patterns of systemic disease, including Wells’ syndrome, vasculitis, atopy, and erythema nodosum.2 We report three male patients of eosinophilic panniculitis with various clinical signs, two of whom had history of trauma or tuberculous pleurisy.
Margarine and butter consumption, eczema and allergic sensitization in children. The LISA birth cohort study
Authors: Sausenthaler Stefanie , Kompauer Iris , Borte Michael , Herbarth Olf , Schaaf Beate , von Berg Andrea , Zutavern Anne , Heinrich Joachim ,   the LISA Study Group
Published: March 2006

It has been hypothesized that margarine intake is associated with allergic diseases. However, the epidemiological evidence in children is limited. The aim of the present study was to assess the relationship between dietary intake of margarine and butter with eczema and allergic sensitization in 2‐yr‐old children. Data of 2582 children at the age of 2 yr with complete information on exposure to diet and allergic outcome were analyzed in a German prospective birth cohort study (LISA). Margarine and butter intake were estimated from a semiquantitative food frequency questionnaire about general fat use at home combined with questions on the child's spread intake. Multiple logistic regression analysis was applied comparing predominant margarine and predominant butter intake with consumption of both butter and margarine. Predominant margarine intake was positively associated with lifetime prevalence of symptomatic eczema (aOR: 1.71; 95% CI: 1.12–2.61) and doctor‐diagnosed eczema (aOR: 2.10; 95% CI: 1.36–3.25) and allergic sensitization against inhalant allergens (aOR: 2.10; 95% CI: 1.01–4.41) at the age of 2 yr. No statistically significant associations were found for butter intake. Stratification for parental history of atopic diseases indicated that children at high risk of atopic diseases have higher effect estimates for margarine intake compared to children without parental history of atopic diseases. Stratification for sex also showed higher effect estimates in boys. Children with predominant margarine consumption had an increased risk for eczema and allergic sensitization, while butter intake was no predictor for allergic diseases. However, we could not determine whether margarine is a causal risk factor or whether other lifestyle factors have influenced this association.
Consumption of fish, butter and margarine during pregnancy and development of allergic sensitizations in the offspring: role of maternal atopy
Authors: Calvani Mauro , Alessandri Claudia , Sopo Stefano Miceli , Panetta Valentina , Pingitore Giuseppe , Tripodi Salvatore , Zappalà Daniela , Zicari Anna Maria ,   the Lazio Association of Pediatric Allergology (APAL) Study Group
Published: March 2006

It has been suggested that changes in dietary habits, particularly increased consumption of ω‐6 polyunsaturated fatty acids (PUFA) and decreased consumption of ω‐3 PUFAs may explain the increase in atopic disease seen in recent years. Furthermore, it seems possible that it is mainly prenatal or very early life environmental factors that influence the development of allergic diseases. It has also been suggested that intrauterine risk factors may act differently if mother themselves suffer from allergic disease.

The aim of this study was to investigate whether the consumption of fish, butter and margarine during pregnancy might influence the development of allergic sensitizations in the offspring. The study population was divided into the offspring of allergic and non‐allergic mothers.

This was a retrospective cohort study enrolling 295 offspring of allergic mothers and 693 of non‐allergic mothers. Information regarding maternal intake of fish, butter and margarine during pregnancy as well as other prenatal and perinatal confounding factors were retrospectively assessed by parental report via a standardized questionnaire. Atopy was determined by skin‐prick tests (SPT) to eight prevalent inhalant allergens and two foods.

In the allergic mothers’ group there is no clear correlation between maternal intakes of fish, butter and margarine and sensitizations to food or inhalants.

In the non‐allergic mothers’ group there was no correlation between butter and margarine intake and food or inhalant sensitizations. On the contrary, a protective effect of fish intake on SPT positivity was observed. In particular, frequent maternal intake (‘2–3 times/wk or more’) of fish reduced the risk of food sensitizations by over a third (aOR 0.23; 95% CI: 0.08–0.69). A similar trend, even if not significant, was found for inhalants. Finally, even in the whole study population, i.e. allergic group plus non‐allergic group, there was a similar trend between increased consumption of fish and decreased prevalence of SPT positivity for foods.

This study shows that frequent intake of fish during pregnancy may contrast the development of SPT sensitizations for foods in the offspring of mothers without atopic disease. Therefore, larger prospective studies are needed, enrolling mothers with and without allergic disease, to confirm these results.
Impact of early dietary gamma‐linolenic acid supplementation on atopic eczema in infancy
Authors: Kitz Richard , Rose Markus A. , Schönborn Heidrun , Zielen Stefan , Böhles Hans J.
Published: March 2006

Polyunsaturated fatty acids (PUFAs) are components of cell membranes and may play an immunomodulating role in the pathogenesis of atopic dermatitis (AD). The goal was to determine the impact of PUFAs on AD by dietary supplementation of infants. Based on the parents’ decision on their babies’ primary feeding, mothers and newborns were randomized to the supplementation with gamma‐linolenic acid (GLA) or placebo for up to 6 months. Breastfed infants received GLA by supplementing their mothers. Formula diet was commercial whey hydrolysate unsupplemented with PUFAs. Of 131 eligible infants, 24 developed AD within the first year of life. Of these, nine belonged to the exclusively breastfed group (n = 58), 14 to the combined‐fed group (n = 53), and one to the never breastfed group (n = 20). We could not find an influence of GLA on the development of AD. In subjects with AD, at 1 yr of age the serum‐immunoglobulin E (IgE) was the lowest in the GLA‐supplemented group A‐subjects. In the GLA‐supplemented group, GLA‐levels in breast milk were similar in atopic and non‐atopic infants. In the non‐supplemented group the GLA‐content of breast milk was 0.07% of total fatty acids in atopic infants vs. 0.17% in non‐atopic infants (p < 0.01). Dietary GLA‐supplementation could not prevent AD. Interestingly, the number of infants developing AD was the lowest in never breastfed children. In infants suffering from AD, GLA‐supplementation seemed to reduce total IgE in the first year of life.
Faecal SIgA secretion in infants fed on pre‐ or probiotic infant formula
Authors: Bakker‐Zierikzee A. M. , van Tol E. A. F. , Kroes H. , Alles M. S. , Kok F. J. , Bindels J. G.
Published: March 2006

Secretory immunoglobulin A (SIgA) plays an important role in the defence of the gastrointestinal tract. The level of faecal SIgA antibody is associated with increased neutralization and clearance of viruses. Formula‐fed infants who lack the transfer of protective maternal SIgA from breast milk may benefit from strategies to support maturation of humoral immunity and endogenous production of SIgA. We aimed at studying the effects of standard, prebiotic and probiotic infant formulas on the faecal SIgA levels. At birth, infants of whom the mother had decided not to breastfeed were allocated to one of three formula groups in a randomized, double‐blind fashion. Nineteen infants received standard infant formula; 19 received prebiotic formula containing a specific mixture of 0.6 g galacto‐oligosaccharides (GOS)/fructo‐oligosaccharides (FOS)/100 ml formula and 19 received probiotic formula containing 6.0 × 109 cfu Bifidobacterium animalis/100 ml formula. Faecal samples were taken on postnatal day 5, day 10, wk 4 and every 4 wk thereafter until wk 32. SIgA in faeces was determined by an enzyme‐linked immunosorbent assay. During the intervention, infants fed on prebiotic formula showed a trend towards higher faecal SIgA levels compared with the standard formula‐fed infants reaching statistical significance at the age of 16 wk. In contrast, infants fed on the probiotic formula showed a highly variable faecal SIgA concentration with no statistically significant differences compared with the standard formula group. Formula‐fed infants may benefit from infant formulas containing a prebiotic mixture of GOS and FOS because of the observed clear tendency to increase faecal SIgA secretion. Adding viable B. animalis strain Bb‐12 to infant formula did not reveal any sign for such a trend.