bluuebunny/crossref_metadata_2025 huggingface dataset:
Importance of canopy structure on photosynthesis in single‐ and multi‐species assemblages of marine macroalgae
Authors: Lise Middelboe Anne , Binzer Thomas
Published: September 2004

Plant communities utilize available irradiance with different efficiency depending not only on their photosynthetic characteristics but also on the canopy structure and density. The importance of canopy structure are well studied in terrestrial plant communities but poorly studied in aquatic plant communities. The objective of this study was to evaluate macroalgal community photosynthesis in artificial constructed communities of one to four species with different morphologies along a range of leaf (i.e.=thallus) area densities. In a laboratory set‐up we measured net photosynthesis and dark respiration in constructed assemblages of macroalgae, excluding effects other than photosynthesis of individual tissue and distribution of photons in the canopy from influencing metabolism. We hypothezised that 1) canopy structure determines the actual rates of photosynthesis relative to the optimal rates and 2) multi‐species communities attain higher maximum photosynthetic rates than single species communities. We found that differences in canopy structure outweighed large differences in tissue photosynthesis resulting in relatively similar maximum community photosynthetic rates among the different single and multi‐species assemblages (20.1–40.5 μmol O2 m−2 s−1). Canopy structure influenced community photosynthesis both at low and high leaf area densities because it determines the ability of macroalgae to use the photosynthetic potential of their individual tissues. Due to an averaging effect the photosynthetic rate at high leaf area density was more similar among multi‐species community than among single‐species communities. Multi‐species communities had, on average, a slightly higher photosynthetic production than expected from photosynthesis of single species communities. Moreover multi‐species communities were capable of exposing new tissue to irradiance up to high densities thereby avoiding a decrease in net photosynthesis. This finding suggests that multi‐species communities may be able to maintain higher biomass per unit ground area than single‐species communities.
Compensatory responses in lepidopteran larvae: a test of growth rate maximisation
Authors: Tammaru Toomas , Nylin Sören , Ruohomäki Kai , Gotthard Karl
Published: September 2004

It is often claimed that some organisms maximise individual growth rates (within limits set by physiological and environmental constraints) whereas others do not. Adequate experimental protocol to test for these hypotheses has not been available. We proceeded from the idea that a maximiser should be unable to further improve its growth performance, i.e. there should be no adaptive plasticity in relative growth rates. In the case of an insect larva always maximising its weight gain, we should thus expect no increase in growth rate following a short‐term environmental perturbation. Another prediction is that initial and final weights of a larval instar should be highly correlated. We applied this approach to test for the growth rate maximiser status of the geometrid moth Epirrita autumnata. Based on various lines of ecological evidence it had previously been suggested that this spring‐feeding species is strongly selected for high growth rates, and may be growing at its maximum physiological potential. Contrary to expectations, the larvae responded to starvation treatments by a subsequent compensatory increase in their relative growth rates. Such a plasticity may indicate that the rates of gaining weight are not maximised even in a ‘classical’ example a time‐constrained organism. This observation supports the idea that endogenous regulation of growth rates is widespread, and it remains to be shown if true maximisation ever exists in nature. In contrast, possibilities to compensate for adverse conditions experienced early in larval development appeared to be limited. This was indicated by the strong correlation between initial weight in the last instar, and pupal weight. Though consistent with our expectations, such an inability to compensate can hardly be ascribed to growth rate maximisation, as indicated by quantitatively similar patterns found in an unrelated species with different ecology, the butterfly Polygonia c‐album.
Contagious seed dispersal beneath heterospecific fruiting trees and its consequences
Authors: Kwit Charles , Levey Douglas J. , Greenberg Cathryn H.
Published: September 2004

An hypothesized advantage of seed dispersal is avoidance of high per capita mortality (i.e. density‐dependent mortality) associated with dense populations of seeds and seedlings beneath parent trees. This hypothesis, inherent in nearly all seed dispersal studies, assumes that density effects are species‐specific. Yet because many tree species exhibit overlapping fruiting phenologies and share dispersers, seeds may be deposited preferentially under synchronously fruiting heterospecific trees, another location where they may be particularly vulnerable to mortality, in this case by generalist seed predators. We demonstrate that frugivores disperse higher densities of Cornusflorida seeds under fruiting (female) Ilexopaca trees than under non‐fruiting (male) Ilex trees in temperate hardwood forest settings in South Carolina, USA. To determine if density of Cornus and/or Ilex seeds influences survivorship of dispersed Cornus seeds, we followed the fates of experimentally dispersed Cornus seeds in neighborhoods of differing, manipulated background densities of Cornus and Ilex seeds. We found that the probability of predation on dispersed Cornus seeds was a function of both Cornus and Ilex background seed densities. Higher densities of Ilex seeds negatively affected Cornus seed survivorship, and this was particularly evident as background densities of dispersed Cornus seeds increased. These results illustrate the importance of viewing seed dispersal and predation in a community context, as the pattern and intensity of density‐dependent mortality may not be solely a function of conspecific densities.
The influence of prey consumption and demographic stochasticity on population growth rate of Isle Royale wolves Canis lupus
Authors: Vucetich John A. , Peterson Rolf O.
Published: September 2004

The relationship between the rates of prey capture and predator population growth is a fundamental aspect of predation, yet it is rarely measured for vertebrate predators. For the isolated wolf population on Isle Royale, annual variation in kill rate explains 22% of the variation in wolf population growth rate. From the slope of this relationship, we estimate that the production efficiency (ratio of production to respiration) of wolves is between 0.5% and 1.5%. More generally, we assess the relative extent to which wolf population growth rate is affected by density dependence, prey availability (moose, Alces alces), winter weather, and demographic stochasticity. Prey availability explains the most variation in wolf growth rate (42%), but this is only recognized after accounting for the influence of a disease‐induced population crash and age structure of the prey population (i.e. number of vulnerable moose, >9 years of age). Demographic stochasticity accounts for approximately 30% of the variation in wolf growth rate. This recognition is important, but not surprising, given that the average population size of Isle Royale wolves is 22. Previous work indicates that the effect of winter climate, as mediated through prey vulnerability and kill rates, is substantial. This work indicates that the direct effect of winter climate is weak, and explains only about 4% of the variation in wolf growth rate (P=0.10).
Linking aboveground and belowground communities: the indirect influence of aphid species identity and diversity on a three trophic level soil food web
Authors: Wardle D. A. , Yeates G. W. , Williamson W. M. , Bonner K. I , Barker G. M
Published: September 2004

There has been a growing recent interest in how foliar herbivory may indirectly affect the belowground sub‐system, but little is known about the belowground consequences of the identity, species composition or diversity of foliar herbivores. We performed an experiment, utilising model grassland communities containing three plant species, in which treatments consisted of addition of each of eight aphid species in single and in two‐ four‐ and eight‐species combinations, as well as an aphid‐free treatment. While aphid species treatments did not affect total plant biomass or productivity, aphid species identity had important effects on the relative abundance of the three plant species. This in turn affected the abundances of each of three groups of secondary consumers in the soil food web (bacterial‐ and fungal‐feeding nematodes, and enchytraeids) but not primary consumers (microbes, herbivorous nematodes) or tertiary consumers (predatory nematodes). The fact that some trophic levels responded to treatments while others did not is consistent with trophic dynamic theory. Aphid species treatments also affected the community composition within each of the herbivorous, microbe‐feeding and top predatory nematode groups, as well as diversity within the first two of these groups. However, aphid species diversity per se had few effects. There were specific instances in which specific aboveground and belowground response variables in two aphid species combinations differed significantly from those in both of the corresponding single aphid species treatments (apparently as a consequence of resource use complementarity between coexisting aphid species), but no instance in which increasing aphid diversity beyond two species had any effect. Our results provide evidence that the identity of aboveground consumers can have effects that propagate through multiple trophic levels in soil food webs in terms of consumer abundance, and composition and diversity within trophic levels.
Regular and flexible modes of division and hystero‐ontogenetic growth in the Silurian rugose coral Stauria favosa
Authors: Ezaki Y. , Yasuhara Y.
Published: September 2004

New modules arise in colonial corals as the result of asexual reproduction. The Silurian rugosan Stauria favosa ordinarily exhibits cerioid coralla with a characteristic cross‐shaped axial structure and a typical pattern of parricidal increase. Quadripartite increase at the sites of the four protosepta is most common, whereas cases of tripartite increase are rare. Parental protosepta are transformed into dividing walls, where the four protosepta first appear with a definite polarity in offset corallites. Daughter corallites inherit metasepta as metasepta, and catasepta as catasepta, within the same quadrants as those of the parent. Metasepta are inserted serially, following Kunth's rule, as is characteristic of rugosan protocorallites. As each daughter corallite derived immediately from the same parent is arranged with identical polarity, it grows equally and evenly both individually and as a group. Daughters thus form protosepta and metasepta under strict phylogenetic and developmental constraints. However, individual corallites grow and reproduce autonomously, by using all available skeleton and space of the parent. Although each module cannot modify essential modes of division, flexibility of the system was via changes in the density and arrangement of corallites, and regulating modes of growth, in tandem with adjacent corallites within the corallum. It is probable that regularity, due to constraints of several origins, as well as flexibility are typical of other rugosan colonies and played an important role in growth dynamics between corallites and corallum.
A Silurian porpitoid hydrozoan from Cumbria, England, and a note on porpitoid relationships
Authors: Fryer Geoffrey , Stanley, Jr. George D.
Published: September 2004

A porpitoid hydrozoan, Pseudodiscophyllum windermerensis gen. et sp. nov., from Cumbria, represented by a well‐preserved internal float (pneumatophore), is only the fourth porpitoid reported from Silurian rocks world‐wide and the first to be found in any geological formation in England. Its circular pneumatophore is more than 110 mm in diameter. Because of the paucity of hard parts, these animals are not common as fossils but may have been important elements of the Palaeozoic oceanic plankton. Although the new species is superficially similar to the Ordovician Discophyllum, there are what appear to be fundamental differences. Similarities to species of Paropsonema, from the Devonian and Silurian, are also probably superficial. The wider relationships of these animals have long been misinterpreted in the palaeontological literature. They are not siphonophores. Correct understanding involves a complete re‐interpretation of various homologies and of the evolutionary history of the group.
Thelodonts and distribution of associated conodonts from the Llandovery–lowermost Lochkovian of the Welsh Borderland
Authors: Märss Tiiu , Miller C. Giles
Published: September 2004

Thelodont scales from the Middle Llandovery–lowermost Lochkovian of southern Britain are described with three new taxa, Loganellia? unispinata sp. nov., Nethertonodus prodigialis gen. et sp. nov. and Paralogania tarranti sp. nov. established, and Paralogania kaarmisensis Märss identified for the first time from Britain. Thelodonts are rare in the Llandovery and Wenlock series where predominantly Loganellia cf. aldridgei Turner, Loganellia scotica (Traquair) and Thelodus sp. are accompanied by coniform conodonts Panderodus Ethington, Decoriconus Cooper and Dapsilodus obliquicostatus (Branson and Mehl). The majority of the material has been recovered from the Ludlow and Přídolí series. Thelodus laevis (Pander) and Paralogania martinssoni (Gross) occur in the lower Gorstian. Paralogania kaarmisensis and Phlebolepis elegans Pander come from the Upper Gorstian–Lower Ludfordian and are associated with the zonal conodont Polygnathoides siluricus Branson and Mehl in the upper Gorstian. Thelodus parvidens Agassiz and T. trilobatus Hoppe dominate in the Upper Ludfordian in association with the rarer zonal conodonts Ozarkodina snajdri (Walliser), O. crispa (Walliser) and O. remscheidensis eosteinhornensis (Walliser). The basal Přídolí Series indicates a change to a thelodont fauna dominated by Paralogania ludlowiensis (Gross) and including Nethertonodus prodigialis. Higher in the Přídolí Series, a succession in faunas includes Katoporodus cf. timanicus (Karataju¯te‐Talimaa), Paralogania tarranti, Loganellia? unispinata and Goniporus alatus (Gross). In the highest Přídolí beds Paralogania kummerowi (Gross) and Loganellia cuneata (Gross) can be traced before the incoming of the lowermost Devonian taxon Turinia pagei (Powrie) along with Nikolivia gutta Karataju¯te‐Talimaa. Correlations with the Baltic are suggested from the Lower Ludlow, Upper Silurian, up to the Lower Lochkovian, Lower Devonian.
Cross‐reactivity among p‐amino group compounds in sulfonamide fixed drug eruption: diagnostic value of patch testing
Authors: Tornero P. , De Barrio M. , Baeza M. L. , Herrero T.
Published: September 2004

We studied 28 patients with fixed drug eruption (FDE) caused by sulfonamide antibiotics to investigate cross‐reactivity between sulfonamide derivatives and p‐amino compounds and to explore the usefulness of patch testing, as an alternative to controlled oral challenge testing (COCT), in diagnosis within this clinical area. COCT with sulfamethoxazole (SMX), sulfadiazine (SDZ), sulfamethizole (SMZ), furosemide (FU), procaine (PRO) and glipizide (GPZ) was performed. Patch testing (PT) with SMX and SDZ was carried out. In all patients, the diagnosis of FDE was confirmed by positive COCT and allergy to trimethoprim ruled out by COCT. 42.8 and 31.8% of the SMX‐induced FDE patients reacted to SMZ and SDZ, respectively. All patients (n = 28) tolerated FU, PRO and GPZ. COCT performed with the 3 sulfonamide antibiotics in 12 patients was positive in 2 subjects with the 3 drugs, in 2 patients only with SMX and SMZ and in the remaining 8, SMX was the only causative drug. PT was positive in 5 of 25 patients positive on COCT. The probability of obtaining a positive PT was higher among patients who had a residual lesion than that among those who lacked this. Cross‐reactivity between different sulfonamide antibiotics is thus variable, being most likely between SMX and SMZ. We have found no cross‐reactivity between sulfonamide antibiotics and other sulfonamide derivatives or p‐amino drugs in FDE. PT is a useful tool in the diagnosis of FDE, especially if there are residual lesions, because it avoided the need for COCT in 20% of patients.
Guidelines for the descriptive presentation and statistical analysis of contact allergy data
Authors: Uter Wolfgang , Schnuch Axel , Gefeller Olaf
Published: September 2004

The present guidelines aim to support clinical researchers in adequately presenting data on contact allergy, and to use statistical tests appropriate for their data. A description of the mode of selection of patients, and of their relevant demographic details, is an essential prerequisite for the correct interpretation of study results. Proportions and rates, if regarded as estimate of these parameters of a target populations, should normally be supplemented with confidence intervals to address precision. Concordance, i.e., agreement between two ratings in a dependent sample, must be quantified with a chance‐corrected measure such as Cohen's kappa coefficient. If the diagnostic quality of an outcome is being assessed, standard measures like sensitivity and specificity, as well as the prevalence‐dependent positive and negative predictive values should be calculated. Often, contact allergy to a certain substance depends on several factors. In this situation, depending on the research question, techniques like stratification, standardization or multifactorial analysis should be employed. With increasing complexity of statistical description and analysis, consulting with a biostatistician is often mandatory.
Contact urticaria and protein contact dermatitis from corn in a patient with serum IgE specific for a salt‐soluble corn protein of low molecular weight
Authors: Cristaudo Antonio , Simonato Barbara , Pasini Gabriella , De Rocco Mariagrazia , Curioni Andrea , Giannattasio Matteo
Published: September 2004

Among the cereals, wheat, rye, barley and oats, have been reported to cause protein contact dermatitis. However, in these cases neither the involvement of an immunological mechanism nor the role of specific protein(s) has been demonstrated. We present a case of protein contact dermatitis from corn. The patient presented with a Type I sensitization to corn, as shown by the presence of specific immunoglobulin (Ig)E and positivity to prick tests with both a flour suspension and the salt‐soluble protein fraction of this cereal. The same corn preparations induced a strong urticarial reaction on scratch testing. This reaction was followed several days later by the appearance of erythema and then eczema at the site of application. When boiled, these preparations became inactive on both prick and scratch testing. Patch tests were negative in all cases. Immunoblotting performed with the patient's serum showed the presence of a unique IgE‐binding protein band with a molecular weight of around 14 kDa, belonging to the salt‐soluble corn protein fraction. Our results give the first clear evidence that cornflour can induce protein contact dermatitis. The IgE‐binding 14‐kDa protein has characteristics identical to those of the trypsin/α‐amylase inhibitors from cereals.
A secondary structural model of the 28S rRNA expansion segments D2 and D3 from rootworms and related leaf beetles (Coleoptera: Chrysomelidae; Galerucinae)
Authors: Gillespie J. , Cannone J. , Gutell R. , Cognato A.
Published: September 2004

We analysed the secondary structure of two expansion segments (D2, D3) of the 28S rRNA gene from 229 leaf beetles (Coleoptera: Chrysomelidae), the majority of which are in the subfamily Galerucinae. The sequences were compared in a multiple sequence alignment, with secondary structure inferred primarily from the compensatory base changes in the conserved helices of the rRNA molecules. This comparative approach yielded thirty helices comprised of base pairs with positional covariation. Based on these leaf beetle sequences, we report an annotated secondary structural model for the D2 and D3 expansion segments that will prove useful in assigning positional nucleotide homology for phylogeny reconstruction in these and closely related beetle taxa. This predicted structure, consisting of seven major compound helices, is mostly consistent with previously proposed models for the D2 and D3 expansion segments in insects. Despite a lack of conservation in the primary structure of these regions of insect 28S rRNA, the evolution of the secondary structure of these seven major motifs may be informative above the nucleotide level for higher‐order phylogeny reconstruction of major insect lineages.
Expression of a sterol carrier protein‐x gene in the Yellow fever mosquito, Aedes aegypti
Authors: Lan Q. , Wessely V.
Published: September 2004

The sterol carrier protein‐x (SCP‐x), a peroxisomal thiolase/nonspecific lipid binding protein, was characterized in the yellow fever mosquito, Aedes aegypti. The Aedes aegypti SCP‐x (AeSCP‐x) has 83% and 75% similarities to Drosophila and mammalian SCP‐x, respectively. However, the AeSCP‐x gene did not produce multiple transcripts, which is characteristic of the vertebrate SCP‐x gene. Levels of AeSCP‐x transcription were higher in larvae and pupae. Gut tissue showed the highest level of AeSCP‐x mRNA in larvae. In adults, low levels of AeSCP‐x transcription were detected in both sexes. Polyclonal antibodies against the sterol carrier protein‐2 (SCP‐2) domain of AeSCP‐x detected two proteins of 62 kDa and 13 kDa. The results indicate that AeSCP‐x is proteolytically cleaved after translation to produce a smaller protein that contains only the SCP‐2 domain, which is similar to post‐translational modification of the vertebrate's SCP‐x to produce multiple products.
Identification of mutations conferring insecticide‐insensitive AChE in the cotton‐melon aphid, Aphis gossypii Glover
Authors: Andrews M. C. , Callaghan A. , Field L. M. , Williamson M. S. , Moores G. D.
Published: September 2004

We have identified two mutations in the ace1 gene of Aphis gossypii that are associated with insensitivity of acetylcholinesterase (AChE) to carbamate and organophosphate insecticides. The first of these, S431F (equivalent to F331 in Torpedo californica), is associated with insensitivity to the carbamate insecticide pirimicarb in a range of A. gossypii clones. The S431F mutation is also found in the peach‐potato aphid, Myzus persicae (Sulzer), and a rapid RFLP diagnostic allows the identification of individuals of both aphid species with a resistant genotype. This diagnostic further revealed the presence of S431 in several other pirimicarb‐susceptible aphid species. The serine at this position in the wild‐type enzyme has only been reported for aphids and provides a molecular explanation of why pirimicarb has a specific aphicidal action. A less specific insensitivity to a wide range of carbamates and organophosphates is associated with a second mutation, A302S (A201 in T. californica).
Emergency cricothyrotomy: a randomised crossover trial comparing the wire‐guided and catheter‐over‐needle techniques
Authors: Fikkers B. G. , Van Vugt S. , Van Der Hoeven J. G. , Van Den Hoogen F. J. A. , Marres H. A. M.
Published: September 2004

In a randomised crossover trial, we compared a wire‐guided cricothyrotomy technique (Minitrach) with a catheter‐over‐needle technique (Quicktrach). Performance time, ease of method, accuracy in placement and complication rate were compared. Ten anaesthesiology and 10 ENT residents performed cricothyrotomies with both techniques on prepared pig larynxes. The catheter‐over‐needle technique was faster than the wire‐guided (48 compared to 150 s, p < 0.001) and subjectively easier to perform (VAS‐score 2.1 vs. 5.6, p < 0.001). Correct positioning of the cannula could be achieved in 95% and 85%, respectively (NS). There was one complication in the catheter‐over‐needle group compared to five in the wire‐guided group. We conclude that the wire‐guided minitracheotomy kit is unsuitable for emergency cricothyrotomies performed by inexperienced practitioners. On the other hand, the catheter‐over‐needle technique appears to be quick, safe and reliable.
A homemade model for training in cricothyrotomy*
Authors: Varaday S. S. , Yentis S. M. , Clarke S.
Published: September 2004

We describe a simple, homemade model for teaching cricothyrotomy. It can easily be constructed from materials found in every anaesthetic room and is cheap, portable and usable several times before requiring replacement. We also describe evaluation of the model in a two‐part study. First, 20 anaesthetic trainees, both with and without prior experience of percutaneous cricothyrotomy/tracheotomy, cannulated the ‘trachea’ using two percutaneous airway sets (Ravussin jet ventilation catheter®[VBM] and Mini‐Trach II Seldinger®[Portex]), then scored the model for realism and usefulness for training. Next, 20 further trainees used the Mini‐Trach II Seldinger on both the homemade model and a commercially available cricothyrotomy/tracheotomy trainer (Pharmabotics), scoring both models as before. In the first part of the study, trainees found the homemade model a useful substitute for practice of percutaneous techniques and teaching. In the second part, both models were rated well, with similar scores. The homemade model is an easily assembled alternative to more expensive models. Both experienced and inexperienced trainees find practising on such models useful.
Ultrasound guidance for a lateral approach to the sciatic nerve in the popliteal fossa
Authors: McCartney C. J. L. , Brauner I. , Chan V. W. S.
Published: September 2004

Descriptions of the use of ultrasound for nerve location have focused on upper limb blocks. We present a case in which ultrasound imaging was used for a lateral approach to the sciatic nerve in the popliteal fossa. Ultrasound images taken proximal to the popliteal crease showed tibial and common peroneal nerves as round hyperechoic structures superficial and lateral to the tibial artery. Under direct ultrasound guidance, we placed a block needle close to the tibial nerve and confirmed its position with nerve stimulation. Injected local anaesthetic was seen on ultrasound as it spread around both tibial and common peroneal nerves.
Nucleotide diversity on the ovine Y chromosome
Authors: Meadows J. R. S. , Hawken R. J. , Kijas J. W.
Published: September 2004

To investigate the impact of male‐mediated introgression during the evolution of sheep breeds, a sequencing approach was used to identify single nucleotide polymorphisms (SNPs) from the male‐specific region of the ovine Y chromosome (MSY). A total of 4380 bp, which comprised nine fragments from five MSY genes was sequenced within a panel of 14 males from seven breeds. Sequence alignment identified a single segregating site, an A/G SNP located approximately 1685 bp upstream of the ovineSRYgene. The resulting estimation of nucleotide diversity (πY = 0.90 ± 0.50 × 10−4) falls towards the lower end of estimates from other species. This was compared with the nucleotide diversity estimated from the autosomal component of the genome. Sequence analysis of 2933 bp amplified from eight autosomal genes revealed a nucleotide diversity (πA = 2.15 ± 0.27 × 10−3) higher than previously reported for sheep. Following adjustment for the contrasting influence of effective population size and a male biased mutation rate, comparison revealed that approximately 10% of the expected nucleotide diversity is present on the ovine Y chromosome.
A melanocortin‐4 receptor (MC4R) polymorphism is associated with performance traits in divergently selected large white pig populations
Authors: Houston R. D. , Cameron N. D. , Rance K. A.
Published: September 2004

The melanocortin‐4 receptor (MC4R) has a vital role in the control of energy balance and the genetic basis of obesity. A polymorphism, which results in the replacement of aspartic acid with asparagine at position 298 of the porcine MC4R gene, within the seventh transmembrane domain, has previously been described. In the current study, allele frequencies for this Asp298Asn polymorphism were investigated in lines of Large White pigs which had been divergently selected for seven generations based on lean food conversion (LFC), lean growth with ad libitum feeding (LGA), lean growth with restricted feeding (LGS) and daily feed intake (DFI). The association of the Asp298Asn polymorphism with performance traits in these lines was assessed. The frequency of Asp298 was higher (P < 0.001) in the LFC high line (0.48) than the low line (0.00), while the frequency of Asn298 was higher (P < 0.01) in the LGA high line (0.22) than the low line (0.04). When analysed across all lines, the Asp298Asn polymorphism was significantly associated with ultrasonic backfat depth, average daily gain and daily feed intake (P < 0.05). Asp298 homozygous animals had mean values of 13.3 mm, 733 g and 1933 g for backfat, average daily gain and daily feed intake respectively, compared with 14.7 mm, 805 g and 2098 g for Asn298 homozygotes. Therefore, the data support a role for the MC4R Asp298Asn polymorphism in the genetic basis of economically important traits in Large White pigs.
Microarray analysis of human milk cells: persistent high expression of osteopontin during the lactation period
Authors: NAGATOMO T , OHGA S , TAKADA H , NOMURA A , HIKINO S , IMURA M , OHSHIMA K , HARA T
Published: September 2004

To continue the search for immunological roles of breast milk, cDNA microarray analysis on cytokines and growth factors was performed for human milk cells. Among the 240 cytokine-related genes, osteopontin (OPN) gene ranked top of the expression. Real-time PCR revealed that the OPN mRNA levels in colostrum cells were approximately 100 times higher than those in PHA-stimulated peripheral blood mononuclear cells (PBMNCs), and 10 000 times higher than those in PB CD14+ cells. The median levels of OPN mRNA in early milk or mature milk cells were more than three times higher than those in colostrum cells. Western blot analysis of human milk showed appreciable expression of full-length and short form proteins of OPN. The concentrations of full-length OPN in early milk or mature milk whey continued to be higher than those in colostrum whey and plasma as assessed by ELISA. The early milk (3–7 days postpartum) contained the highest concentrations of OPN protein, while the late mature milk cells (1 years postpartum) had the highest expression of OPN mRNA of all the lactating periods. The results of immunohistochemical and immunocytochemical staining indicated that OPN-producing epithelial cells and macrophages are found in actively lactating mammary glands. These results suggest that the persistently and extraordinarily high expression of OPN in human milk cells plays a potential role in the immunological development of breast-fed infants.
Anti-myeloperoxidase antibodies in sera from patients with propylthiouracil-induced vasculitis might recognize restricted epitopes on myeloperoxidase molecule
Authors: YE H , ZHAO M-H , GAO Y , GUO X-H , WANG H-Y
Published: September 2004

Myeloperoxidase (MPO) is one of the major target antigens of antineutrophil cytoplasmic antibodies (ANCA) in primary systemic vasculitis. It is known that propylthiouracil (PTU) could induce MPO–ANCA-positive vasculitis. The production of anti-MPO antibodies in patients with PTU-induced vasculitis may be different from that in patients with primary microscopic polyangiitis (MPA). One possible reason for this may be differences in epitope recognition. The aim of this study is to compare the epitopes of antibodies to MPO in sera from patients with PTU-induced vasculitis (n = 10) and MPA (n = 10). The sera were collected and used to inhibit monoclonal antibodies against human MPO (3D8 and 6B9) and affinity purified, horseradish peroxidase conjugated human anti-MPO antibodies (Pab1-HRP, Pab2-HRP) in a competitive inhibition enzyme-linked immunosorbent assay (ELISA) system using soluble human MPO as solid phase ligand. The Pab1-HRP and Pab2-HRP were affinity purified from plasma exchanges of a patient with PTU-induced vasculitis and a patient with MPA, respectively. The inhibition rates were evaluated and compared between the PTU and primary MPA groups. In the PTU group all 10 sera could inhibit 3D8: the average inhibition rate was 44.7% ± 5.0%; 9/10 sera could inhibit 6B9: the average inhibition rate was 35.6% ± 6.0%. However, in the MPA group all 10 sera could inhibit 3D8 and 6B9; the average inhibition rates were 68.4% ± 16.1% (P < 0.01) and 62.2% ± 17.2% (P < 0.01), respectively. Sera in both the PTU and MPA groups could inhibit Pab1-HRP and the inhibition rates were 81.4% ± 9.4%versus 86.6% ± 17.2% (P > 0.05). However, the average inhibition rate for Pab2-HRP in the MPA group was significantly higher than that in the PTU group (76.3% ± 7.8%versus 58.9% ± 15.5%, P < 0.01). We conclude that anti-MPO antibodies from patients with PTU-induced vasculitis and from patients with primary MPA could recognize more than one epitope on the native MPO molecule. Although the epitopes overlapped between the two groups, the epitopes of anti-MPO antibodies from patients with PTU-induced vasculitis might be more restricted.
Multiple loci are linked with anti-red blood cell antibody production in NZB mice−comparison with other phenotypes implies complex modes of action
Authors: LEE N J , RIGBY R J , GILL H , BOYLE J J , FOSSATI-JIMACK L , MORLEY B J , VYSE T J
Published: September 2004

The New Zealand Black (NZB) mouse strain is a model of autoimmune haemolytic anaemia (AHA) and systemic lupus erythematosus (SLE), characterized by the production of anti-red blood cell (RBC) antibodies and anti-nuclear antibodies (ANA), respectively. A linkage analysis was carried out in an (NZB × BALB/c) F2 cross in order to identify loci involved in the production of both anti-RBC IgM and IgG antibodies. These regions of linkage were compared with linkage data to ANA from the same cohort and other linkage analyses involving New Zealand mice. Four previously described NZB loci linked to anti-RBC antibodies were confirmed, and eight novel loci linked to this trait were also mapped: five of which were of NZB origin, and three derived from the non-autoimmune BALB/c background. A comparison between loci linked with anti-RBC antibodies and ANA demonstrated many that co-localize, suggesting the presence of genes that result in the general breaking of tolerance to self-antigen. Furthermore, the observation that some loci were associated only with the anti-RBC response suggests an antigen specific mechanism in addition to a general breaking of tolerance. A locus linked with anti-RBC antibodies and ANA on distal chromosome 7 in this cohort is orthologous to one on the q arm of human chromosome 11, a region linked to AHA and ANA in human SLE.
Up-regulation of IL-18 and predominance of a Th1 immune response is a hallmark of lupus nephritis
Authors: CALVANI N , RICHARDS H B , TUCCI M , PANNARALE G , SILVESTRIS F
Published: September 2004

There is evidence that nephritis is dominated by a Th1 immune response in systemic lupus erythematosus. Since IL-18 promotes polarization of the immune response toward Th1, we investigated the role of this cytokine in lupus nephritis (LN). A total of 133 lupus patients and 44 healthy subjects were enrolled. Demographic and clinical characteristics with renal biopsy data were recorded. IL-18 along with IFN-γ and IL-4, two prototypical of Th1 and Th2 cytokines, were measured in serum by ELISA. Peripheral blood lymphocytes were analysed by flow cytometry for IFN-γ and IL-4. IL-18 expression was determined by immunohistochemistry in 13 renal biopsy specimens from patients with LN and 2 controls. Serum IL-18 was higher in lupus patients than in controls. Levels of IL-18 correlated with urinary microalbumin and were increased in patients with LN when compared to those without LN. IL-18 expression was also increased within the glomeruli of nephritic patients and was primarily detected within the mesangial matrix and in infiltrating mononuclear cells. Measurement of IFN-γ and IL-4 in either sera or peripheral blood lymphocytes showed high IFN-γ along with low IL-4 expression in LN patients compared to patients without nephritis. A positive correlation between serum IL-18 and IFN-γ levels was found. IL-18 may play a prominent role in the pathogenesis of LN by promoting a cytokine imbalance towards a Th1 immune response. Measurement of IL-18 may be helpful for the early identification of lupus patients with LN and may help gauge the response to treatment in patients with active LN undergoing treatment.
Persistent HIV-1 replication does not explain low levels of T-cell interferon-γmRNA and elevated serum NO2–/NO3– in patients with stable CD4 T-cell responses to HAART
Authors: LEE S , ALMEIDA C-A , FRENCH M A H , PRICE P
Published: September 2004

HIV-1 infected patients adherent to HAART and displaying stable increases in CD4 T-cell counts differ in their control of HIV replication and one might expect this to reflect depressed immune function. The importance of virological control in functional immune reconstitution was investigated in HIV-1 infected patients who maintained high or undetectable plasma HIV RNA levels over 2–4 years on HAART (discordant and complete responders, respectively). Immunocompetance and immune activation were assessed directly ex vivo and after a short period of culture, as HIV replication in cultures from viraemic patients may artificially depress responses. Expression of cytokine (interferon-γ, interleukin-5) and chemokine receptor (CCR5, CRTH2) mRNA were determined and soluble CD30 and NO2–/NO3– were measured in sera. Unstimulated cells from all patients had low levels of IFNγ mRNA relative to uninfected controls. Discordant responders had more IFNγ, IL-5 and CCR5 mRNA in mitogen-stimulated PBMC than complete responders, where the difference could be attributed to CD8-T-cells. Serum NO2–/NO3– levels were significantly higher in all patients than controls, with no difference between complete and discordant responders. Serum CD30 levels were significantly higher in discordant responders. These data indicate a persistent immune deficit in immune reconstituted patients irrespective of HIV viral load and associate persistent viral replication with lymphocyte activation, probably involving CD8 T-cells.
Human endogenous retroviruses: transposable elements with potential?
Authors: NELSON P N , HOOLEY P , RODEN D , DAVARI EJTEHADI H , RYLANCE P , WARREN P , MARTIN J , MURRAY P G
Published: September 2004

Human endogenous retroviruses (HERVs) are a significant component of a wider family of retroelements that constitute part of the human genome. These viruses, perhaps representative of previous exogenous retroviral infection, have been integrated and passed through successive generations within the germ line. The retention of HERVs and isolated elements, such as long-terminal repeats, could have the potential to harm. In this review we describe HERVs within the context of the family of known transposable elements and survey these viruses in terms of superantigens and molecular mimics. It is entirely possible that these mechanisms provide the potential for undesired immune responses.
Burkholderia pseudomallei stimulates low interleukin-8 production in the human lung epithelial cell line A549
Authors: UTAISINCHAROEN P , ANUNTAGOOL N , ARJCHAROEN S , LENGWEHASATIT I , LIMPOSUWAN K , CHAISURIYA P , SIRISINHA S
Published: September 2004

Melioidosis is a life-threatening disease caused by Burkholderia pseudomallei. The lung is the most commonly affected organ, resulting in abscess formation in patients with chronic melioidosis. Previous study has shown that B. pseudomallei was able to invade and multiply in epithelial cells. In the present study, we have demonstrated that B. pseudomallei is able to stimulate interleukin 8 (IL-8) production from the human alveolar lung epithelium cell line A549. However, the level of IL-8 production was significantly lower than when the cells were infected with other Gram-negative bacteria such as Salmonella enterica serovar Typhi (S. typhi) which were used for comparison. The degree of IκBα degradation in the B. pseudomallei-infected cells was lower than that of the S. typhi-infected cells, suggesting that B. pseudomallei is also a poorer cell activator. Inhibition of B. pseudomallei invasion by cytochalasin D did not interfere with either IL-8 production or IκBα degradation, indicating that bacterial uptake is not required for the production of this chemokine. Thus, it appears that the signalling initiated by the interaction of B. pseudomallei with the epithelial cell surface is sufficient for epithelial cell activation.
Stem wood properties of Populus tremuloides, Betula papyrifera and Acer saccharum saplings after 3 years of treatments to elevated carbon dioxide and ozone
Authors: Kaakinen Seija , Kostiainen Katri , Ek Fredrik , Saranpää Pekka , Kubiske Mark E. , Sober Jaak , Karnosky David F. , Vapaavuori Elina
Published: September 2004

The aim of this study was to examine the effects of elevated carbon dioxide [CO2] and ozone [O3] and their interaction on wood chemistry and anatomy of five clones of 3‐year‐old trembling aspen (Populus tremuloides Michx.). Wood chemistry was studied also on paper birch (Betula papyrifera Marsh.) and sugar maple (Acer saccharum Marsh.) seedling‐origin saplings of the same age. Material for the study was collected from the Aspen Free‐Air CO2 Enrichment (FACE) experiment in Rhinelander, WI, USA, where the saplings had been exposed to four treatments: control (C; ambient CO2, ambient O3), elevated CO2 (560 ppm during daylight hours), elevated O3 (1.5 × ambient during daylight hours) and their combination (CO2+O3) for three growing seasons (1998–2000). Wood chemistry responses to the elevated CO2 and O3 treatments differed between species. Aspen was most responsive, while maple was the least responsive of the three tree species. Aspen genotype affected the responses of wood chemistry and, to some extent, wood structure to the treatments. The lignin concentration increased under elevated O3 in four clones of aspen and in birch. However, elevated CO2 ameliorated the effect. In two aspen clones, nitrogen in wood samples decreased under combined exposure to CO2 and O3. Soluble sugar concentration in one aspen clone and starch concentration in two clones were increased by elevated CO2. In aspen wood, α‐cellulose concentration changed under elevated CO2, decreasing under ambient O3 and slightly increasing under elevated O3. Hemicellulose concentration in birch was decreased by elevated CO2 and increased by elevated O3. In aspen, elevated O3 induced statistically significant reductions in distance from the pith to the bark and vessel lumen diameter, as well as increased wall thickness and wall percentage, and in one clone, decreased fibre lumen diameter. Our results show that juvenile wood properties of broadleaves, depending on species and genotype, were altered by atmospheric gas concentrations predicted for the year 2050 and that CO2 ameliorates some adverse effects of elevated O3 on wood chemistry.
Variation in climate warming along the migration route uncouples arrival and breeding dates
Authors: Ahola Markus , Laaksonen Toni , Sippola Katja , Eeva Tapio , Rainio Kalle , Lehikoinen Esa
Published: September 2004

Migratory species are of special concern in the face of global climate change, since they may be affected by changes in the wintering area, along the migration route and at the breeding grounds. Here we show that migration and breeding times of a trans‐Saharan migrant, the pied flycatcher Ficedula hypoleuca, closely follow local temperatures along the migration route and at the breeding grounds. Because of differences in long‐term temperature trends of short within‐spring periods, the migration period and the time interval between migration and breeding dates of this species have extended in SW Finland. Temperatures in northern parts of Central Europe have risen at the time when the first migrants arrive there, facilitating their migration northward. Temperatures later in the spring have not changed, and the last individuals arrive at the same time as before. The timing of breeding has not advanced because temperatures at the breeding site after arrival have not changed. These results show that the pied flycatchers can speed up their migration in response to rising temperatures along the migration route. Our results strongly indicate that the effects of climate change have to be studied at the appropriate time and geographical scales for each species and population concerned.
Simulation of potential range expansion of oak disease caused byPhytophthora cinnamomiunder climate change
Authors: Bergot Magali , Cloppet Emmanuel , Pérarnaud Victorine , Déqué Michel , Marçais Benoît , Desprez‐Loustau Marie‐Laure
Published: September 2004

This study examines the effects of climate warming on one of the most widely distributed and destructive forest pathogens,Phytophthora cinnamomi. In Europe, the winter survival of the pathogen is the dominant cue for the development of the disease it causes to oaks, especiallyQuercus roburandQ. rubra. The potential pathogen and disease geographic ranges were compared in France between two reference periods, 1968–1998 and 2070–2099. Simulations were obtained by combining a physiologically based approach predicting the pathogen winter survival in relation to microhabitat temperature (in the phloem of infected trees) with a regionalized climatic scenario derived from a global circulation model. Positive anomalies in winter temperatures calculated with this scenario were in the range 0.5–5°C between the periods 2070–2099 and the 1968–1998, according to sites and months. As a consequence, higher annual rates ofP. cinnamomisurvival were predicted, resulting in a potential range expansion of the disease of one to a few hundred kilometers eastward from the Atlantic coast within one century. Based on this example, the study emphasizes the need of a better understanding of the impacts of global change on the biotic constraint constituted by plant pathogens.