bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti‐idiotype antibody induced cellular immunity in mice transgenic for human carcinoembryonic antigen
Authors: Saha Asim , Chatterjee Sunil K. , Foon Kenneth A. , Bhattacharya‐Chatterjee Malaya
Published: May 2006

In the present study, we have analysed the detailed cellular immune mechanisms involved in tumour rejection in carcinoembryonic antigen (CEA) transgenic mice after immunization with dendritic cells (DC) pulsed with an anti‐idiotype (Id) antibody, 3H1, which mimics CEA. 3H1‐pulsed DC vaccinations resulted in induction of CEA specific cytotoxic T lymphocyte (CTL) responses in vitro and the rejection of CEA‐transfected MC‐38 murine colon carcinoma cells, C15, in vivo (Saha et al.,Cancer Res 2004; 64: 4995–5003). These CTL mediated major histocompatibility complex (MHC) class I‐restricted tumour cell lysis, production of interferon‐γ (IFN‐γ) and tumour necrosis factor‐α (TNF‐α), and expression of Fas ligand (FasL) and TNF‐related apoptosis‐inducing ligand (TRAIL) in response to C15 cells. CTL used perforin‐, FasL‐, and TRAIL‐mediated death pathways to lyse C15 cells, although perforin‐mediated killing was the predominant lytic mechanism in vitro. The cytokines IFN‐γ and TNF‐α synergistically enhanced surface expression of Fas, TRAIL receptor, MHC class I and class II on C15 cells that increased the sensitivity of tumour cells to CTL lysis. CTL activity generated in 3H1‐pulsed DC immunized mice was directed against an epitope defined by the idio‐peptide LCD‐2, derived from 3H1. In vivo lymphocyte depletion experiments demonstrated that induction of CTL response and antitumour immunity was dependent on both CD4+ and CD8+ T cells. The analysis of splenocytes of immunized mice that had rejected C15 tumour growth revealed up‐regulated surface expression of memory phenotype Ly‐6C and CD44 on both CD4+ and CD8+ T cells. The adoptive transfer experiments also suggested the role of both CD4+ and CD8+ T cells in this model system. Furthermore, mice that had rejected C15 tumour growth, developed tumour‐specific immunological memory.
Technical and management perceptions of enterprise information system importance, implementation and benefits
Authors: Chang Hsin Hsin
Published: May 2006

Abstract.  This paper compares information systems (IS) integration in high‐tech organizations from the information technology (IT) and general management perspectives. All the organizations studied have experience of integrated Enterprise Resource Planning systems, and some with their extension to Supply Chain Management and Customer Relationship Management systems. The operational scope of the sample systems, and senior IT and general management perceptions of the importance of their functions, benefits and implementation success factors, obtained by qualitative interviews with 49 senior managers and a quantitative survey of 219 high‐tech companies, are described and compared. Although the opinions expressed indicate some mutual hostility, IT and general management perceptions of IS implementation were very similar. IT managements overall importance assessments of business functions were more strongly correlated with their overall level of implementation, and they tended to rate system benefits and system reliability more highly. The significance of these findings is discussed and some suggestions for further investigation, placing them in a wider context, are made. Arguably, the similarities found are more important than the differences.
Value‐focused assessment of information system security in organizations
Authors: Dhillon Gurpreet , Torkzadeh Gholamreza
Published: May 2006

Abstract.  Information system (IS) security continues to present a challenge for executives and professionals. A large part of IS security research is technical in nature with limited consideration of people and organizational issues. The study presented in this paper adopts a broader perspective and presents an understanding of IS security in terms of the values of people from an organizational perspective. It uses the value‐focused thinking approach to identify ‘fundamental’ objectives for IS security and ‘means’ of achieving them in an organization. Data for the study were collected through in‐depth interviews with 103 managers about their values in managing IS security. Interview results suggest 86 objectives that are essential in managing IS security. The 86 objectives are organized into 25 clusters of nine fundamental and 16 means categories. These results are validated by a panel of seven IS security experts. The findings suggest that for maintaining IS security in organizations, it is necessary to go beyond technical considerations and adopt organizationally grounded principles and values.
Alleviation of pre‐exposure of mouse brain with low‐dose 12C6+ ion or 60Co gamma‐ray on male reproductive endocrine damages induced by subsequent high‐dose irradiation
Authors: Zhang Hong , Liu Bing , Zhou Qingming , Zhou Guangming , Yuan Zhigang , Li Wenjian , Duan Xin , Min Fengling , Xie Yi , Li Xiaoda
Published: May 2006

Irradiation has been widely reported to damage organisms by attacking on proteins, nucleic acid and lipids in cells. However, radiation hormesis after low‐dose irradiation has become the focus of research in radiobiology in recent years. To investigate the effects of pre‐exposure of mouse brain with low‐dose 12C6+ ion or 60Co gamma (γ)‐ray on male reproductive endocrine capacity induced by subsequent high‐dose irradiation, the brains of the B6C3F1 hybrid strain male mice were irradiated with 0.05 Gy of 12C6+ ion or 60Co γ‐ray as the pre‐exposure dose, and were then irradiated with 2 Gy as challenging irradiation dose at 4 h after pre‐exposure. Serum pituitary gonadotropin hormones, follicle‐stimulating hormone (FSH) and luteinizing hormone (LH), testosterone, testis weight, sperm count and shape were measured on the 35th day after irradiation. The results showed that there was a significant reduction in the levels of serum FSH, LH, testosterone, testis weight and sperm count, and a significant increase in sperm abnormalities by irradiation of the mouse brain with 2 Gy of 12C6+ ion or 60Co γ‐ray. Moreover, the effects were more obvious in the group irradiated by 12C6+ ion than in that irradiated by 60Co γ‐ray. Pre‐exposure with low‐dose 12C6+ ion or 60Co γ‐ray significantly alleviated the harmful effects induced by a subsequent high‐dose irradiation.
Relationship between seminal ascorbic acid and sperm DNA integrity in infertile men
Authors: Song Gyun Jee , Norkus Edward P. , Lewis Vivian
Published: May 2006

Ascorbic acid has recently been reported to protect sperm DNA from the damage induced by exogenous oxidative stress in vitro. But, there is no report on seminal ascorbic acid and sperm DNA fragmentation in infertile men. In this study, we asked whether sperm DNA damage correlates with seminal ascorbic acid levels. Sperm DNA fragmentation index (DFI) was analysed in 75 men by flow cytometry after acridine orange staining. We also measured the levels of seminal plasma ascorbic acid and total antioxidant capacity. Abnormal sperm DNA integrity (DFI ≥ 30%) was observed in 12% of the patients with normal semen parameters and in 52% of the patients with abnormal semen parameters. There were significant correlations between the level of DFI and conventional semen parameters including sperm count, motility and morphology (r = −0.29, −0.55 and −0.53 respectively; p < 0.05). Seminal ascorbic acid level was significantly lower in the patients with leucospermia than the patient with normal semen parameters. Interestingly, a significantly greater percentage of men with abnormal DFI were observed in the patients with low levels of seminal ascorbic acid compared with those with normal or high levels of ascorbic acid (59% vs. 33%, p < 0.05). Men with insufficient seminal ascorbic acid frequently have sperm DNA damage.
Aerial photographs as a tool for assessing the regional dynamics of the invasive plant speciesHeracleum mantegazzianum
Authors: MÜLLEROVÁ JANA , PYŠEK PETR , JAROŠÍK VOJTĚCH , PERGL JAN
Published: May 2006

The initiation of an invasion event is rarely dated in studies of alien plants. Data from aerial photographs documenting the invasion from the outset facilitate the quantification of the rate of spread, allowing researchers to analyse species’ population dynamics and providing a basis for management.

For 10 sites invaded byHeracleum mantegazzianumin the Slavkovský les, Czech Republic, aerial photographs from 11 sampling dates between 1947 (before invasion started) and 2000 were analysed. The area covered by the invader was measured digitally in a 60‐ha section of landscape, and information obtained on invaded habitats, year of invasion, flowering intensity and structure of patches. Invaded area was regressed on residence time (time since the beginning of invasion) and regression slopes were used to measure the rate of spread. Data were analysed byancova, multiple regression and path analysis.

Pastures and fields contributed 84·7% toHeracleumtotal cover, forest and scrub 13·7% and human settlements 1·6% at the later stage of invasion. The direct effect of the rate of invasion on invaded area (0·82) was greater than that of residence time (0·22), but the total effect (direct and indirect) of residence time was only slightly less (0·79) than that of the rate of invasion (0·82). As invasion proceeded, the populations spread from linear habitats to the surrounding landscape. Mean rate of areal spread was 1261 m2year−1and that of linear spread 10·8 m year−1. Flowering intensity did not exhibit any significant trend over time.

Synthesis and applications.The strong effect of the rate of spread on the invaded area indicates that local environmental conditions hardly limit the spread ofHeracleum. The species is easily detectable on aerial photographs taken at flowering and early fruiting times, from June to August. Knowledge gained from aerial photographs allows managers to identify dispersal foci and to focus control efforts on linear landscape structures with developing populations. Knowledge of the rate of spread and habitat vulnerability to invasion facilitates the identification of areas at highest risk of immediate invasion.
Restoring ecological function in temperate grassy woodlands: manipulating soil nutrients, exotic annuals and native perennial grasses through carbon supplements and spring burns
Authors: PROBER SUZANNE M. , THIELE KEVIN R. , LUNT IAN D. , KOEN T. B.
Published: May 2006

Ecological invasions are often associated with persistent changes to underlying ecological processes. Restoration of invaded communities is dependent on manipulation of these processes to favour the target species composition and impart resistance to further invasion. We applied these principles to extensively degraded grassy woodlands in temperate agricultural regions of Australia, where widespread invasion by mediterranean annuals is related to altered ecological processes such as soil nutrient cycling.

We investigated carbon supplementation and spring burns, in association with re‐establishment of native perennial grasses, as potential management tools for manipulating nitrogen cycling, soil seed banks and establishment conditions in degraded woodland understoreys. Through these mechanisms we aimed to enhance native cover and increase resistance to invasion by exotic annuals.

In two contrasting degraded remnants, repeated sucrose applications temporarily reduced soil nitrate to inferred pre‐European levels, which dramatically reduced growth of exotic annuals and enhanced native perennial abundance. Repeated spring burns did not reduce soil nitrate but reduced exotic annual grasses through effects on soil seed banks and/or establishment conditions.

Spring burns and carbon supplements both significantly enhanced establishment of Themeda australis, a dominant tussock grass prior to European settlement. Combinations of T. australis seed addition and either spring burning or carbon supplements enhanced native plant abundance more effectively than treatments without seed addition.

Within 18 months of their establishment, T. australis seedlings significantly reduced soil nitrate in some treatments, providing a preliminary indication that re‐establishment of a dense sward of this species may restore ecosystem function to a low‐nitrate state that favours native perennials over exotic annuals.

Synthesis and applications. Ecological restoration can be viewed as targeted intervention in species–environment interactions, whereby ecological conditions are manipulated to enhance establishment or vigour of key species, and these species in turn help restore ecological processes that favour the target species composition. In grassy ecosystems re‐establishing a perennial sward of appropriate native tussock grasses may be critical for restoring pre‐disturbance nitrogen cycles and improving resistance to invasion by exotic annuals. Carbon supplements and spring burns facilitate this process through complementary mechanisms.
Artificial marine structures facilitate the spread of a non‐indigenous green alga, Codium fragile ssp. tomentosoides, in the north Adriatic Sea
Authors: BULLERI FABIO , AIROLDI LAURA
Published: May 2006

Artificial structures have become ubiquitous features of coastal landscapes. Although they provide novel habitats for the colonization of marine organisms, their role in facilitating biological invasions has been largely unexplored.

We investigated the distribution and dynamics of the introduced green alga, Codium fragile ssp. tomentosoides, at a variety of spatial scales on breakwaters in the north Adriatic Sea, and analysed experimentally the mechanisms underlying its establishment. We assessed the provision of sheltered habitats by breakwaters, the role of disturbance (e.g. from recreational harvesting and storms) acting at different times of the year, and the interactions between Codium and the dominant native space‐occupier, the mussel Mytilus galloprovincialis.

Codium fragile ssp. tomentosoides has established viable populations on artificial structures along the shores investigated. The density, cover and size (length, branching and weight) of annual erect thalli of Codium was enhanced in sheltered conditions, resulting in the monopolization of landward low‐shore habitats of breakwaters.

On the landward sides of breakwaters, disturbance enhanced recruitment of Codium. The time when bare space was provided within mussels beds was crucial. Removal of mussels in April or January did not affect the recruitment of Codium, whereas harvest in August, shortly before Codium gamete release, doubled its success. On the seaward sides of breakwaters, the effects of disturbance were more complex because mussels both inhibited recruitment of Codium and provided shelter from wave action to adult thalli.

Synthesis and applications. Artificial structures can provide suitable habitats for non‐indigenous marine species and function as corridors for their expansion. Physical (wave exposure) and biotic (resident assemblages) features of artificial habitats can be important determinants of their susceptibility to biological invasions. Alternative options in the design of artificial structures and effective management of native assemblages could minimize their role in biological invasions. In particular, increased water motion and retention of space by mussels in spring–summer would be effective in reducing the ability of C. fragile ssp. tomentosoides to persist on the breakwaters investigated in this study.
Profiting from prior information in Bayesian analyses of ecological data
Authors: McCARTHY MICHAEL A. , MASTERS PIP
Published: May 2006

Most ecological studies include prior information only implicitly, usually in their design or the discussion of results. In this study, two examples demonstrate that using Bayesian statistics to incorporate basic ecological principles and prior data can be very cost‐effective for increasing confidence in ecological research.

The first example is based on examining the effects of an experimental manipulation of the habitat of mulgaraDasycercus cristicauda, a marsupial of inland Australia. The second example is based on observational mark–recapture data to estimate the annual survival of the European dipperCinclus cinclus, a passerine in France.

In the mulgara example, the prior information obtained from an observational study increased confidence that there was an adverse effect of experimental habitat manipulation on the species. The results suggested that the capture rate of mulgara was reduced to approximately one‐quarter by reduction of vegetation cover.

In the European dipper example, prior information based on the body mass of the species and estimates of annual survival of other European passerines was shown to be worth between 1 and 5 years of mark–recapture field data.

Synthesis and applications. Body mass can be used to predict annual survival of European passerines and other animals. Results of observational studies can provide prior information in experimental studies of impacts of habitat change. By using Bayesian methods, such prior information, if represented in a coherent and logical way, can be cost‐effective for adding certainty to ecological studies.
Evaluating the impact of a biological control agent Carmenta mimosa on the woody wetland weed Mimosa pigra in Australia
Authors: PAYNTER QUENTIN
Published: May 2006

Evaluation of the success of biological control agents is essential to improve the efficiency and safety of future programmes. This study assessed the impact of Carmenta mimosa, a stem‐mining moth, introduced into northern Australia as a biological control agent of mimosa Mimosa pigra. Litter fall, seed banks, vegetation cover, density and age structure of mimosa stands were compared using data collected at nine sites where Carmenta mimosa was present and eight sites where it was initially absent.

Mimosa seed rain was negatively correlated with Carmenta mimosa damage and declined by more than 90% at the highest Carmenta mimosa densities. Seed banks also declined with Carmenta mimosa damage.

Percentage cover of competing vegetation was significantly higher under stands defoliated by Carmenta mimosa and this inhibited mimosa seedling establishment and apparently increased the susceptibility of mimosa to fire, by increasing fuel loads beneath stands.

Four of the eight stands where Carmenta mimosa was absent expanded and none contracted. In contrast, none of the nine stands where Carmenta mimosa was present expanded and three contracted. Analysis of the age structure of mimosa stands indicated that contracting stands were typified by an absence of seedling regeneration.

In contrast to previous studies, no impact could be attributed to the flower feeder Coelocephalapion pigrae or to the stem‐mining moth Neurostrota gunniella, whilst the bruchid Acanthoscelides puniceus consumed up to only c. 10% of seed. However, it is argued that, while these agents are unlikely to suppress dense mimosa thickets, they may reduce the rate mimosa can expand.

Synthesis and applications. By preventing stand regeneration, Carmenta mimosa is predicted to cause widespread reductions in mimosa populations and should therefore be redistributed to areas of mimosa where it is absent. Differences between the age structures of stands with Carmenta mimosa present may highlight how biological control could succeed for a suite of woody legume weeds with long‐lived seed banks.
Parasites and the island syndrome: the colonization of the western Mediterranean islands by Heligmosomoides polygyrus (Dujardin, 1845)
Authors: Nieberding C. , Morand S. , Libois R. , Michaux J. R.
Published: May 2006

Aim  Populations of free‐living vertebrates on islands frequently differ from their mainland counterparts by a series of changes in morphometric, life‐history, behavioural, physiological and genetic traits, collectively referred to as the ‘island syndrome’. It is not known, however, whether the ‘island syndrome’ also affects parasitic organisms. The present study establishes the colonization pattern of the Mediterranean islands by the nematode Heligmosomoides polygyrus, a direct and specific parasite of rodent hosts of the Apodemus genus, and evaluates the effects of island colonization by this species on two components of the island syndrome: the loss of genetic diversity and the enlargement of the ecological niche.

Location  Heligmosomoides polygyrus was sampled on seven western Mediterranean islands − Corsica, Crete, Elba, Majorca, Minorca, Sardinia and Sicily − as well as in 20 continental locations covering the Mediterranean basin.

Methods  The mitochondrial cytochrome b gene (690 base pairs) was sequenced in 166 adult H. polygyrus individuals sampled in the 27 continental and island locations. Phylogenetic reconstructions in distance, parsimony, maximum likelihood and Bayesian posterior probabilities were carried out on the whole cytochrome b gene data set. The levels of nucleotide, haplotype and genetic divergence (Kimura two‐parameter distance estimator) diversities were estimated in each island population and in the various continental lineages.

Results  Phylogenetic reconstructions show that the mainland origins of H. polygyrus were continental Spain for the Balearic Islands (Majorca, Minorca), northern Italy for the Tyrrhenian Islands (Corsica, Sardinia, Elba), southern Italy for Sicily, and the Balkan region for Crete. A comparison of island H. polygyrus populations with their mainland source populations revealed two characteristic components of the island syndrome in this parasite. First, island H. polygyrus populations display a significant loss of genetic diversity, which is related (r2 = 0.73) to the distance separating the island from the mainland source region. Second, H. polygyrus exhibits a niche enlargement following insularization. Indeed, H. polygyrus in Corsica is present in both A. sylvaticus and Mus musculus domesticus, while mainland H. polygyrus populations are present exclusively in Apodemus hosts.

Main conclusions  Our results show that H. polygyrus has undergone a loss of genetic diversity and a niche (host) enlargement following colonization of the western Mediterranean islands. To our knowledge, this study provides the first evidence for components of the ‘island syndrome’ in a parasitic nematode species.
Ecological traits influence the current distribution and range of an island endemic bird
Authors: Illera Juan Carlos , Díaz Mario , Nogales Manuel
Published: May 2006

Aim The aim of this paper is to investigate the causes of the current restricted distribution of a narrow‐range endemic bird species, the Canary Islands stonechat,Saxicola dacotiae.

Location Eastern islands of the Canary Islands archipelago.

Methods We compared climatic patterns (temperature and rainfall), habitat and microhabitat structure, food availability during a full annual cycle, and the abundance of native avian competitors and predators inside and outside the species’ range. Three study areas, located in similar habitats on nearby islands, were studied: northern Fuerteventura, close to the northern border of the species’ range; southern Lanzarote, 22 km from the nearest site occupied by stonechats; and the Lobos islet, 10 km from the nearest occupied site and 2 km from the coast of Fuerteventura.

Results The cover of suitable habitats (slopes with high cover of large shrubs, stony fields and ravines) and microhabitats (shrubs and boulders) and the abundance of arthropods during the breeding period of Canary Islands stonechats were lower outside than inside the species’ range. Temperature, rainfall and the abundance of competitors and predators inside and outside the species’ range did not differ significantly.

Main conclusions Ecological requirements explaining the distribution of the Canary Islands stonechat within its range seem to be the main factor hindering its settlement on nearby islands. Geological and palaeoclimatic processes, as well as past and current human impact, could also have constrained the distribution of this narrow‐range endemic bird species.
Post‐fire recovery of Mediterranean ground ant communities follows vegetation and dryness gradients
Authors: Arnan Xavier , Rodrigo Anselm , Retana Javier
Published: May 2006

Aim In the Mediterranean Basin, the main forest communities vary in their ability to recover after fire. In this study we analyse the effects of fire on ant communities occurring in various vegetation types distributed along a geographical gradient in the western Mediterranean region.

Location The study was carried out in burned and unburned habitats of 22 sites corresponding to eight vegetation types distributed along a gradient of dryness throughout Catalonia (north‐east Spain).

Methods We placed five pairs of plots (one plot located in the burned area and the second one placed in the unburned margin) per site. We compared ant communities in these unburned and burned plot types 8 years after fire using pitfall traps. Traps were set out in mid‐May and mid‐July. We analysed the structure and composition of ant communities in the burned and unburned areas of these vegetation types usinganovatests, correspondence analysis (CA) and linear regression.

Results The resilience of ant communities varies with vegetation type. Ant communities in forests with high resilience also recover rapidly after fire, while those in forests that do not recover after fire show the lowest resilience. Species richness does not depend on burning or vegetation type. The resilience of these Mediterranean ant communities to fire is related to the environmental characteristics of the region where they live. Accordingly, differences between burned and unburned habitats are smaller for ant communities in areas with higher water deficit in summer than for those in moister ones.

Main conclusions The structure and composition of ant communities after fire depends on the level of direct mortality caused by the fire. It affects ant species differently, as determined by the habitats used for nesting and foraging. The reestablishment of vegetation cover depends on forest composition before the fire. As vegetation cover determines resource and microhabitat availability and competitive relationships among species, forest composition before the fire also affects post‐fire recovery of ant communities to the medium‐term. Finally, ant communities living in drier areas recover more quickly after fire than those living in moister ones. This pattern might be because in areas with higher water deficit there are more species characteristic of open environments, which are habitats similar to those generated after fire.
Biogeographical tests of the vicariance model in Mediterranean land snails
Authors: Hausdorf Bernhard , Hennig Christian
Published: May 2006

Aim To investigate the importance of vicariance in shaping land snail faunas.

Location Three data sets of Mediterranean land snails were analysed: Helicoidea of the Iberian Peninsula and the complete land snail faunas of the central and eastern Aegean Islands and of Israel and Palestine.

Methods The vicariance model predicts a clustering of species ranges. We tested for clustering of species ranges with a Monte Carlo simulation. For this simulation we used a null model that generates range data sets in such a way that their range size distribution, their species richness distribution and the spatial autocorrelation of the ranges approximate the parameters in the real data set. Biotic elements (clusters of species ranges) were delimited with model‐based Gaussian clustering. A second prediction of the vicariance model is that closely related species belong to different biotic elements. This was tested with a chi‐squared test.

Results The distribution areas of the Iberian Helicoidea and the Israeli/Palestinian land snails are significantly clustered. The same is true for Israeli/Palestinian land snail species belonging to groups with geographically restricted species. However, the clustering is not significant in the complete central and eastern Aegean land snail data set, the Iberian Helicoidea species, and the central and eastern Aegean land snails belonging to groups with geographically restricted species. Contrary to the prediction of the vicariance model, closely related Iberian Helicoidea species and Israeli/Palestinian land snails belong significantly more often to the same biotic element than expected by chance. The null hypothesis that closely related species are homogeneously distributed across biotic elements cannot be rejected only for the data set that includes the Israeli/Palestinian land snails belonging to groups with geographically restricted species.

Main conclusions The patterns found in the central and eastern Aegean land snail and the Iberian Helicoidea data sets do not correspond with the predictions of the vicariance model. This indicates that speciation modes other than vicariance were frequent, or that the distribution areas of many species in these faunas were largely modified by extensive post‐speciation dispersal and/or regional extinction. Hardly any possible vicariance events that might have contributed to the origin of the observed biotic elements in the Israeli/Palestinian land snail fauna could be identified. On the contrary, the biotic elements of the Israeli/Palestinian land snail fauna correspond with ecological factors. Vicariance has had only a limited influence on current biogeographical patterns in Mediterranean land snails.
Chlamydia trachomatis‐derived deubiquitinating enzymes in mammalian cells during infection
Authors: Misaghi Shahram , Balsara Zarine R. , Catic Andre , Spooner Eric , Ploegh Hidde L. , Starnbach Michael N.
Published: May 2006

Chlamydia trachomatis is an obligate intracellular bacterium that causes a variety of diseases in humans. C. trachomatis has a complex developmental cycle that depends on host cells for replication, during which gene expression is tightly regulated. Here we identify two C. trachomatis proteases that possess deubiquitinating and deneddylating activities. We have designated these proteins ChlaDub1 and ChlaDub2. The genes encoding ChlaDub1 and ChlaDub2 are present in all Chlamydia species except for Chlamydia pneumoniae, and their catalytic domains bear similarity to the catalytic domains of other eukaryotic ubiquitin‐like proteases (Ulp). The C. trachomatis DUBs react with activity‐based probes and hydrolyse ubiquitinated and neddylated substrates. ChlaDub1 and ChlaDub2 represent the first known bacterial DUBs that possess both deubiquitinating and deneddylating activities.
Gastric electrical stimulation for intractable vomiting in patients with chronic intestinal pseudoobstruction
Authors: Andersson S. , Lönroth H. , Simrén M. , Ringström G. , Elfvin A. , Abrahamsson H.
Published: May 2006

Abstract  Gastric electrical stimulation (GES) is effective for medically refractory nausea and vomiting in patients with idiopathic or diabetic gastroparesis (DGP). We studied whether GES has similar effects in chronic intestinal pseudoobstruction (CIP). Patients referred for chronic small bowel (SB) motor dysfunction requiring parenteral nutrition and having a weekly vomiting frequency (WVF) ≥7 refractory to prokinetics and antiemetics were included. Patients were implanted for high‐frequency GES 12 stimuli min−1, laparoscopy being the first‐line implantation procedure. Results were compared with those obtained in 11 DGP patients. Three patients with familial CIP and one patient with postsurgical CIP fulfilled the criteria. Gastric emptying was delayed in two and was normal in two patients. SB transit time was markedly delayed. Laparoscopy was used in three patients, one patient required laparotomy. During GES, WVF decreased from 24 (mean) before GES to 6.9 at 12 months and 7.5 at last visit. Vomiting reduction was 50–90% at last visit. For the DGP patients, WVF decreased from 23 before GES to 3.5 at 12 months and 3.5 (P < 0.01) at last visit. In patients with CIP and medically refractory vomiting, GES seems to have an anti‐vomiting effect comparable to that seen in patients with severe DGP. GES should be considered as a therapeutic option for these patients.
Hyperexcitability of convergent colon and bladder dorsal root ganglion neurons after colonic inflammation: mechanism for pelvic organ cross‐talk
Authors: Malykhina A. P. , Qin C. , Greenwood‐van Meerveld B. , Foreman R. D. , Lupu F. , Akbarali H. I.
Published: May 2006

Abstract  Clinical studies reveal concomitant occurrence of several gastrointestinal and urologic disorders, including irritable bowel syndrome and interstitial cystitis. The purpose of this study was to determine the mechanisms underlying cross‐organ sensitization at the level of dorsal root ganglion (DRG) after acute and subsided gastrointestinal inflammation. DiI (1,1′‐dioctadecyl‐3,3,3′,3′‐tetramethylindocarbocyanine perchlorate) and Fast Blue were injected into the distal colon and urinary bladder of male rats, respectively. Convergent DRG neurons were found in L1‐L3 and L6‐S2 ganglia with an average distribution of 14% ± 2%. The resting membrane potential (RMP) of cells isolated from upper lumbar (UL) ganglia was −59.8 ± 2.7 mV, whereas lumbosacral (LS) neurons were more depolarized (RMP = −49.4 ± 2.1 mV, P ≤ 0.05) under control conditions. Acute trinitrobenzene sulfonic acid (TNBS) colitis (3 days) decreased voltage and current thresholds for action potential firing in LS but not UL convergent capsaicin‐sensitive neurons. This effect persisted for 30 days in the absence of overt colonic inflammation. The current threshold for action potential (AP) firing in UL cells was also decreased from 165.0 ± 24.5 pA (control) to 85.0 ± 19.1 pA at 30 days (P ≤ 0.05), indicating increased excitability. The presence of a subpopulation of colon‐bladder convergent DRG neurons and their persistent hyperexcitability after colonic inflammation provides a basis for pelvic organ cross‐sensitization.
Regional gastric emptying abnormalities in functional dyspepsia and gastro‐oesophageal reflux disease
Authors: Gonlachanvit S. , Maurer A. H. , Fisher R. S. , Parkman H. P.
Published: May 2006

Abstract  To characterize proximal and distal stomach emptying in functional dyspepsia (FD) and gastro‐oesophageal reflux disease (GORD). Eighty‐three patients underwent gastric emptying (GE) scintigraphy and symptom scoring for the evaluation of upper gastrointestinal symptoms and were divided into three groups: FD (n = 25), GORD (n = 20) and FD + GORD (n = 38). Total, proximal and distal gastric retention were determined scintigraphically and compared with normal controls. Delayed total GE was observed in each subgroup: FD (56%), GORD (45%) and FD + GORD (55%). Greater proximal gastric retention was observed after meal ingestion in GORD compared to FD. Greater distal gastric retention was observed in FD and FD + GORD but it was only mild in GORD. Nausea, vomiting, early satiety, distention and regurgitation were associated with proximal gastric retention whereas there was no symptom associated with distal gastric retention. Multiple regression demonstrated total gastric retention at 30 min and 1 h was positively correlated with regurgitation whereas early proximal gastric retention was positively correlated with regurgitation and negatively correlated with nausea. Selective abnormalities of proximal and distal stomach emptying were demonstrated in GORD and FD. GORD and FD symptoms were associated with proximal gastric retention suggesting that proximal stomach motor function may be important in the pathogenesis of symptoms associated with these disorders.
Synthesis of low molecular weight thiols in response to Cd exposure in Thlaspi caerulescens
Authors: HERNÁNDEZ‐ALLICA J. , GARBISU C. , BECERRIL J. M. , BARRUTIA O. , GARCÍA‐PLAZAOLA J. I. , ZHAO F. J. , MCGRATH S. P.
Published: May 2006

In this study, we investigated the accumulation of phytochelatins (PCs) and other low molecular weight (LMW) thiols in response to Cd exposure in two contrasting ecotypes differing in Cd accumulation. Using a root elongation test, we found that the highly accumulating ecotype Ganges was more tolerant to Cd than the low Cd‐accumulation ecotype Prayon. l‐buthionine‐(S,R)‐sulphoximine (BSO), a potent inhibitor of the γ‐glutamylcysteine synthetase (γ‐ECS) (an enzyme involved in the PC biosynthetic pathway), increased the Cd sensitivity of Prayon, but had no effect on Ganges. Although PC accumulation increased in response to Cd exposure, no significant differences were observed between the two ecotypes. Cd exposure induced a dose‐dependent accumulation of both Cys and a still unidentified LMW thiol in roots of both ecotypes. Root accumulation of Cys and this thiol was higher in Ganges than in Prayon; the ecotypic differences were more pronounced when the plants were treated with BSO. These findings suggest that PCs do not contribute to the Cd hypertolerance displayed by the Ganges ecotype of Thlaspi caerulescens, whereas Cys and other LMW thiols might be involved.
Guard cells in albino leaf patches do not respond to photosynthetically active radiation, but are sensitive to blue light, CO2 and abscisic acid
Authors: ROELFSEMA M. ROB G. , KONRAD KAI R. , MARTEN HOLGER , PSARAS GEORGE K. , HARTUNG WOLFRAM , HEDRICH RAINER
Published: May 2006

Stomatal openings can be stimulated by light through two signalling pathways. The first pathway is blue light specific and involves phototropins, while the second pathway mediates a response to photosynthetically active radiation (PAR). This second pathway was studied with the use of albino Vicia faba plants and variegated leaves of Chlorophytum comosum. Treatment of V. faba with norflurazon (Nf) inhibits the synthesis of carotenoids and leads to albino leaves with guard cells that lack functional green chloroplasts. Guard cells in albino leaf patches of C. comosum, however, do contain photosynthetically active chloroplasts. Stomata in albino leaf patches of both plants did not respond to red light, although blue light could still induce stomatal opening. This shows that the response to PAR is not functioning in albino leaf patches, even though guard cells of C. comosum harbour chloroplasts. Stomata of Nf‐treated plants still responded to CO2 and abscisic acid (ABA). The size of Nf‐treated guard cells was increased, but impalement studies with double‐barrelled microelectrodes revealed no changes in ion‐transport properties at the plasma membrane of guard cells. Blue light could hyperpolarize albino guard cells by triggering outward currents with peak values of 37 pA in albino plants and 51 pA in green control cells. Because of the inhibition of carotenoid biosynthesis, Nf‐treated V. faba plants contained only 4% of the ABA content found in green control plants. The ABA dose dependence of anion channel activation in guard cells was shifted in these plants, causing a reduced response to 10 µm ABA. These data show that despite the dramatic changes in physiology caused by Nf, the gross responsiveness of guard cells to blue light, CO2 and ABA remains unaltered. Stomata in albino leaf patches, however, do not respond to PAR, but require photosynthetically active mesophyll cells for this response.
Transcriptional regulators of stamen development in Arabidopsis identified by transcriptional profiling
Authors: Mandaokar Ajin , Thines Bryan , Shin Byongchul , Markus Lange B. , Choi Goh , Koo Yeon J. , Yoo Yung J. , Choi Yang D. , Choi Giltsu , Browse John
Published: May 2006

In Arabidopsis, jasmonate is required for stamen and pollen maturation. Mutants deficient in jasmonate synthesis, such as opr3, are male‐sterile but become fertile when jasmonate is applied to developing flower buds. We have used ATH1 oligonucleotide arrays to follow gene expression in opr3 stamens for 22 h following jasmonate treatment. In these experiments, a total of 821 genes were specifically induced by jasmonate and 480 genes were repressed. Comparisons with data from previous studies indicate that these genes constitute a stamen‐specific jasmonate transcriptome, with a large proportion (70%) of the genes expressed in the sporophytic tissue but not in the pollen. Bioinformatics tools allowed us to associate many of the induced genes with metabolic pathways that are probably upregulated during jasmonate‐induced maturation. Our pathway analysis led to the identification of specific genes within larger families of homologues that apparently encode stamen‐specific isozymes. Extensive additional analysis of our dataset identified 13 transcription factors that may be key regulators of the stamen maturation processes triggered by jasmonate. Two of these transcription factors, MYB21 and MYB24, are the only members of subgroup 19 of the R2R3 family of MYB proteins. A myb21 mutant obtained by reverse genetics exhibited shorter anther filaments, delayed anther dehiscence and greatly reduced male fertility. A myb24 mutant was phenotypically wild‐type, but production of a myb21myb24 double mutant indicated that introduction of the myb24 mutation exacerbated all three aspects of the myb21 phenotype. Exogenous jasmonate could not restore fertility to myb21 or myb21myb24 mutant plants. Together with the data from transcriptional profiling, these results indicate that MYB21 and MYB24 are induced by jasmonate and mediate important aspects of the jasmonate response during stamen development.
Novel micro‐RNAs and intermediates of micro‐RNA biogenesis from moss
Authors: Talmor‐Neiman Mali , Stav Ran , Frank Wolfgang , Voss Bjoern , Arazi Tzahi
Published: May 2006

Micro‐RNAs (miRNAs) are one class of small non‐coding RNAs that have important regulatory roles in higher plants. Much less is known about their prevalence and function in lower land plants. Previously we cloned 100 non‐structural small RNAs from the moss Physcomitrella patens but could annotate only 11 as miRNAs. To identify additional moss miRNAs among cloned small RNAs we have analyzed their genomic sequences for a characteristic miRNA precursor‐like structure. This analysis revealed 19 new moss miRNAs that are predicted to be encoded by 22 putative foldbacks. Northern blot analysis confirmed the expression of 14 new miRNA representatives. Half of these were gametophore specific, the rest were detected at low levels in the protonema. We predicted 12 genes as targets of nine new miRNAs. Three of these show homology to transcription factors and the others appear to play roles in diverse physiological processes including light and cytokine signaling, which have not to date been shown to be regulated by a miRNA in flowering plants. Four target genes, which show homology to ATN1‐like protein kinase, NAC transcription factors and a cytokinin receptor, have been validated by miRNA‐mediated mRNA cleavage. In addition, our analysis revealed that seven small RNAs represent miRNA* and three represent intermediates of pre‐miRNA processing, providing evidence for specific DICER‐like cleavage steps during miRNA biogenesis in moss. Our findings suggest that miRNAs are common in mosses and set the stage for the elucidation of their varied biological functions.
Investigation of the p.Ser278Arg polymorphism of the autoimmune regulator (AIRE) gene in alopecia areata
Authors: Pforr J. , Blaumeiser B. , Becker T. , Freudenberg‐Hua Y. , Hanneken S. , Eigelshoven S. , Cuyt I. , De Weert J. , Lambert J. , Kruse R. , Nöthen M. M. , Betz R. C.
Published: May 2006

A recent study has suggested that the g.961C>G (p.Ser278Arg) variant of the autoimmune regulator (AIRE) gene contributes to susceptibility to alopecia areata (AA). We attempted to replicate this finding using a case‐control sample of Belgian‐German origin (273 patients and 283 controls). Despite adequate power, our study results do not support a significant association of the risk allele in our AA patient sample. This remained the case when we stratified our sample according to severity and family history of disease. Our study results do not support the hypothesis that the g.961C>G (p.Ser278Arg) polymorphism of the AIRE gene is associated with an increased risk for AA.
The 32‐base pair deletion of the chemokine receptor 5 gene (CCR5‐Δ32) is not associated with primary sclerosing cholangitis in 363 Scandinavian patients
Authors: Melum E. , Karlsen T. H. , Broomé U. , Thorsby E. , Schrumpf E. , Boberg K. M. , Lie B. A.
Published: May 2006

CCR5 is a chemokine receptor expressed on T‐cells and macrophages. A 32‐base pair deletion in the chemokine receptor 5 gene (CCR5‐Δ32) leads to a non‐functional receptor. Conflicting evidence exists whether this deletion is associated with primary sclerosing cholangitis (PSC). We genotyped the CCR5‐Δ32 variant in 363 PSC patients and 366 controls. No significant increase in the Δ32 allele frequency was detected in the PSC patients compared to controls (12.7% vs 10.7% OR = 1.22, 95% CI [0.88, 1.68], P = 0.23). Survival analysis did not reveal any significant effects from CCR5‐Δ32 genotypes on disease progression. Thus, in this study (power > 90%, given OR = 2, α = 0.05), we were unable to replicate previous findings and our results do not support an involvement of CCR5‐Δ32 in either PSC susceptibility or progression.
Conservation of leukocyte cell surface proteins: implications for the generation of monoclonal antibodies against newly identified leukocyte cell surface proteins
Authors: Zola H. , Mavrangelos C. , Millard D. J. , Nicholson I. C.
Published: May 2006

The availability of mouse monoclonal antibodies has been integral to the classification of human leukocyte cell surface proteins under the ‘Cluster of Differentiation’ or ‘CD’ nomenclature system. The sequencing of the human genome has identified many more proteins that have characteristics similar to the known leukocyte cell surface proteins, but which have not so far been identified using monoclonal antibodies. One factor that may have limited the generation of monoclonal antibodies to some of these proteins is the high level of sequence conservation between the mouse and human proteins, in particular in the extracellular regions that are recognized by most of the widely used antibodies. An alternative approach is to use a more distant species, such as chickens, for the generation of antibody reagents. Here we compare the extent of amino acid differences in the protein CD molecules expressed by human leukocytes and their mouse and chicken homologs. The analysis confirms that the human proteins are more similar to the mouse homologs than the chicken homologs. The results indicate that chicken antibodies have the potential to be used as an alternative to mouse reagents where human‐mouse sequence conservation is high.